1. Weekly report POS 508 [POS508]

(22.01.-30.01.2017

2. Weekly report POS 508 [POS508]

(30.01-06.02.2017

Bacterial Colonization and Vertical Distribution of Marine Gel Particles (TEP and CSP) in the Arctic Fram Strait

Gel particles—a class of abundant transparent organic particles—have increasingly gathered attention in marine research. Field studies on the bacterial colonization of marine gels however are still scarce. So far, most studies on respective particles have focused on the upper ocean, while little is known on their occurrence in the deep sea. Here, we report on the vertical distribution of the two most common gel particle types, which are polysaccharide-containing transparent exopolymer particles (TEP) and proteinaceous Coomassie stainable particles (CSP), as well as numbers of bacteria attached to gel particles throughout the water column, from the surface ocean down to the bathypelagial (< 3,000 m). Our study was conducted in the Arctic Fram Strait during northern hemispheres' summer in 2015. Besides data on the bacterial colonization of the two gel particle types (TEP and CSP), we present bacterial densities on different gel particle size classes according to 12 different sampling depths at four sampling locations. Gel particles were frequently abundant at all sampled depths, and their concentrations decreased from the euphotic zone to the dark ocean. They were colonized by bacteria at all sampled water depths with risen importance at the deepest water layers, where fractions of bacteria attached to gel particles (%) increased within the total bacterial community. Due to the omnipresent bacterial colonization of gel particles at all sampled depths in our study, we presume that euphotic production of this type of organic matter may affect microbial species distribution within the whole water column in the Fram Strait, down to the deep sea. Our results raise the question if changes in the bacterial community composition and functioning on gel particles occur over depth, which may affect microbial respiration and remineralization rates of respective particles in different water layers

Weekly Report POS 531 [POS531]

(18.01.2019 - 27.01.2019

When Logs Become Big Data

As we move into the era of Cloud Computing and the Internet of Things, an increasing amount of devices are connected to our networks and this is expected to be doubled in the next five years. This results in large amounts of logs, sensor data and other metrics that has to be stored and analyzed. In this project three databases are compared from a log analytics viewpoint. These databases are Cassandra, Elasticsearch and PostgreSQL. Experiments are designed and run to test the general performance of the databases with write and read operations, in addition to some experiments that are designed to look like normal use cases from log analytics. Some of the experiments are repeated in an Elasticsearch cluster of varying sizes to see how this influences the performance. The results indicate that all the databases get quite similar results in the general performance tests, but that Cassandra does very poorly in the use cases that try to simulate log analytics. It is concluded that PostgreSQL and Elasticsearch are both good options. And the results from the clustering experiment indicate that Elasticsearch would scale up very well, meaning that it is well prepared for future needs

Limited sinking of Phaeocystis during a 12 days sediment trap study

There is a controversy discussion about the contribution of the genus Phaeocystis to the vertical carbon export with evidence for and against sedimentation of Phaeocystis. So far, the presence of Phaeocystis in sinking matter was investigated with methods depending on morphological features (microscopy) and fast degradable substances (biochemical analyses). In this study, we determine the occurrence and abundance of Phaeocystis antarctica in short-term sediment traps and the overlying water column during a 12-day time period in the Atlantic sector of the Southern Ocean with 454-pyrosequencing and microscopy counting. In the sediment trap samples, we only found few sequences belonging to Phaeocystis, which was not reflecting the situation in the water column above. The cell counts showed the same results. We conclude that Phaeocystis cells are not generally transported downwards by active sinking or other sinking processes

Impact of Microsetella norvegica on carbon flux attenuation and as a secondary producer during the polar night in the subarctic Porsangerfjord

It is known that Microsetella norvegica feed on phytoplankton and provide an important link to higher trophic levels in Arctic fjords, such as fish sprat (Sprattus sprattus) and three-spined stickleback (Gasterosteus aculeatus). It has recently been suggested that M. norvegica may also contribute substantially to carbon flux attenuation during periods of high abundance. However, we still know very little about how seasonal variations in abundance and vertical distribution of M. norvegica impact the efficiency of the biological carbon pump in Arctic fjords. We investigated the role of Microsetella norvegica, a small harpacticoid copepod, for particulate organic carbon flux attenuation via aggregate feeding in a subarctic fjord. We quantified the vertical distribution and abundance of M. norvegica, phytoplankton, and marine snow simultaneously with a Digital Autonomous Video Plankton Recorder in Porsangerfjord, northern Norway, between August 2013 and November 2014. We estimated the highest abundance of M. norvegica as 4.86x106 individuals m-2 in October. Our results suggest that M. norvegica preferred diatoms over both marine snow and the prymnesiophyte Phaeocystis pouchetii during euphotic bloom conditions. However, during oligotrophic conditions when phytoplankton were scarce, M. norvegica switched to marine snow as a food source. M. norvegica has the potential to explain 1.4% and 0.29% of the total carbon flux attenuation in October and November, respectively. These results suggest that small copepods feed on settling detritus when no alternative food is available. Detritus feeding by M. norvegica may have an ecological impact during the polar night, both via direct carbon flux attenuation, but also as secondary producers in periods with low primary production. Currently small copepods such as M. norvegica are not included in carbon budgets or large-scale modelling, but considering their potentially high abundance they may represent an important but overlooked pathway in both the carbon cycle and trophic level interactions

The Exercise of Mandate:How Mandatory Service Implementation- Promoted the Use of E-Government Services in Denmark.

Danish e-government has for two decades been considered a global leader. Among the various reasons for this Danish success, this article explores the mandatory online self-service and digital post initiative (2012-2015) as one of the effective, strategic contributions in increasing the wider penetration and use of digital public services in Danish society. Although the mandatory shift to digital service could have caused negative reactions from public servants and citizens, this was not the case in Denmark. By reviewing a set of mandatory digital public services in the Danish context, four key aspects are identified as essential drivers. That is: pride as citizens, high levels of trust and privacy, usability and accessibility of e-government services, and informal support by family and community. The article discusses the four supportive prerequisites as keys for enforcing the implementations, which could otherwise be seen as national coercive dirigisme