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- Dutkiewicz, Stephanie, et al.
(author)
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Multiple biotic interactions establish phytoplankton community structure across environmental gradients
- 2024
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In: Limnology and Oceanography. - : John Wiley & Sons. - 0024-3590 .- 1939-5590. ; 69:5, s. 1086-1100
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Journal article (peer-reviewed)abstract
- The combination of taxa and size classes of phytoplankton that coexist at any location affects the structure of the marine food web and the magnitude of carbon fluxes to the deep ocean. But what controls the patterns of this community structure across environmental gradients remains unclear. Here, we focus on the North East Pacific Transition Zone, a similar to 10 degrees region of latitude straddling warm, nutrient-poor subtropical and cold, nutrient-rich subpolar gyres. Data from three cruises to the region revealed intricate patterns of phytoplankton community structure: poleward increases in the number of cell size classes; increasing biomass of picoeukaryotes and diatoms; decreases in diazotrophs and Prochlorococcus; and both increases and decreases in Synechococcus. These patterns can only be partially explained by existing theories. Using data, theory, and numerical simulations, we show that the patterns of plankton distributions across the transition zone are the result of gradients in nutrient supply rates, which control a range of complex biotic interactions. We examine how interactions such as size-specific grazing, multiple trophic strategies, shared grazing between several phytoplankton size classes and heterotrophic bacteria, and competition for multiple resources can individually explain aspects of the observed community structure. However, it is the combination of all these interactions together that is needed to explain the bulk compositional patterns in phytoplankton across the North East Pacific Transition Zone. The synthesis of multiple mechanisms is essential for us to begin to understand the shaping of community structure over large environmental gradients.
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- Ahmad, Mohd Riduan, et al.
(author)
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Lightning interference in multiple antennas wireless communication systems
- 2012
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In: Journal of Lightning Research. - : Bentham open. - 1652-8034. ; 4, s. 155-165
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Journal article (peer-reviewed)abstract
- This paper analyzes the interference of lightning flashes with multiple antennas wireless communicationsystems operating in the microwave band at 2.4 GHz and 5.2 GHz. A bit error rate (BER) measurement method was usedto evaluate BER and packet error rate (PER) during 5 heavy thunderstorms on January 25 and March 17 to 20, 2011,respectively. In addition, BER measurements also were done on January 21 and March 30, 2011 under fair weather (FW)conditions providing a baseline for comparison. The Transmitter-Receiver separation was fixed at 10 meter with line-ofsight(LOS) consideration. We infer that lightning interfered with the transmitted digital pulses which resulted in a higherrecorded BER. The maximum recorded BER was 9.9·10-1 and the average recorded BER and PER were 2.07·10-2 and2.44·10-2 respectively during the thunderstorms with the average fair weather BER and PER values under the influence ofadjacent channel interference (ACI) and co-channel interference (CCI) being 1.75·10-5 and 7.35·10-6 respectively. Weconclude that multiple antennas wireless communication systems operating at the microwave frequency can besignificantly interfered by lightning.
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4. |
- Kristiansson, J., et al.
(author)
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Prolonged vasopressor support during hip-fracture surgery is a risk factor for enhanced mortality
- 2019
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In: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172. ; 63:1, s. 46-54
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Journal article (peer-reviewed)abstract
- Background Hip fracture is a common injury in the elderly population and is associated with high morbidity and mortality. Intraoperative hypotension is commonly noted, and is often treated with vasopressors (VP), however, to what extent is unknown. We set out to examine retrospectively how many hip fracture-patients received VP perioperatively and further to investigate if VP treatment is connected to increased mortality. Method Data on VP treatment were captured from medical and anaesthesia journals, and if so, data were investigated to find potential confounders. Patients were divided into (a) no VP, (b) VP by injection, (c) VP by infusion <3 hours, and (d) VP by infusion >= 3 hours to achieve stratification. Results Nine hundred and ninety-seven patients were included. About 80.4% received VP treatment. The 30-day mortality rates in subgroups were 3.6%, 5.4%, 6.4% and 19.1% respectively. The 90-day mortality rates were 6.7%, 10.3%, 11.6% and 30.3% respectively. Finally, the same patient groups had 365-day mortality rates of 12.8%, 20.0%, 23.3% and 44.9% respectively. We found a significant increase in mortality (30-90-365 days) in patients receiving VP infusion >= 3 hours, after adjusting for confounding factors. There was no increased mortality in patients treated by injection and by infusion Conclusion Vasopressor treatment is common during hip fracture surgery. Patients treated with VP infusion >= 3 hours have increased mortality, while patients treated with injections or infusion
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5. |
- Nguyen, C. T., et al.
(author)
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A Comprehensive Survey of Enabling and Emerging Technologies for Social Distancing : Part I Fundamentals and Enabling Technologies
- 2020
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In: IEEE Access. - : Institute of Electrical and Electronics Engineers (IEEE). - 2169-3536. ; 8, s. 153479-153507
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Journal article (peer-reviewed)abstract
- Social distancing plays a pivotal role in preventing the spread of viral diseases illnesses such as COVID-19. By minimizing the close physical contact among people, we can reduce the chances of catching the virus and spreading it across the community. This two-part paper aims to provide a comprehensive survey on how emerging technologies, e.g., wireless and networking, artificial intelligence (AI) can enable, encourage, and even enforce social distancing practice. In this Part I, we provide a comprehensive background of social distancing including basic concepts, measurements, models, and propose various practical social distancing scenarios. We then discuss enabling wireless technologies which are especially effect- in social distancing, e.g., symptom prediction, detection and monitoring quarantined people, and contact tracing. The companion paper Part II surveys other emerging and related technologies, such as machine learning, computer vision, thermal, ultrasound, etc., and discusses open issues and challenges (e.g., privacy-preserving, scheduling, and incentive mechanisms) in implementing social distancing in practice.
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6. |
- Nguyen, C. T., et al.
(author)
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A Comprehensive Survey of Enabling and Emerging Technologies for Social Distancing - Part II : Emerging Technologies and Open Issues
- 2020
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In: IEEE Access. - : Institute of Electrical and Electronics Engineers (IEEE). - 2169-3536. ; 8, s. 154209-154236
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Journal article (peer-reviewed)abstract
- This two-part paper aims to provide a comprehensive survey on how emerging technologies, e.g., wireless and networking, artificial intelligence (AI) can enable, encourage, and even enforce social distancing practice. In Part I, an extensive background of social distancing is provided, and enabling wireless technologies are thoroughly surveyed. In this Part II, emerging technologies such as machine learning, computer vision, thermal, ultrasound, etc., are introduced. These technologies open many new solutions and directions to deal with problems in social distancing, e.g., symptom prediction, detection and monitoring quarantined people, and contact tracing. Finally, we discuss open issues and challenges (e.g., privacy-preserving, scheduling, and incentive mechanisms) in implementing social distancing in practice. As an example, instead of reacting with ad-hoc responses to COVID-19-like pandemics in the future, smart infrastructures (e.g., next-generation wireless systems like 6G, smart home/building, smart city, intelligent transportation systems) should incorporate a pandemic mode in their standard architectures/designs.
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- Paschinger, K., et al.
(author)
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N-glycan antennal modifications are altered in Caenorhabditis elegans lacking the HEX-4 N-acetylgalactosamine-specific hexosaminidase
- 2023
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In: Journal of Biological Chemistry. - : Elsevier BV. - 0021-9258. ; 299:4
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Journal article (peer-reviewed)abstract
- Simple organisms are often considered to have simple gly-comes, but plentiful paucimannosidic and oligomannosidic glycans overshadow the less abundant N-glycans with highly variable core and antennal modifications; Caenorhabditis ele-gans is no exception. By use of optimized fractionation and assessing wildtype in comparison to mutant strains lacking either the HEX-4 or HEX-5 beta-N-acetylgalactosaminidases, we conclude that the model nematode has a total N-glycomic po-tential of 300 verified isomers. Three pools of glycans were analyzed for each strain: either PNGase F released and eluted from a reversed-phase C18 resin with either water or 15% methanol or PNGase Ar released. While the water-eluted frac-tions were dominated by typical paucimannosidic and oligo-mannosidic glycans and the PNGase Ar-released pools by glycans with various core modifications, the methanol-eluted fractions contained a huge range of phosphorylcholine-modified structures with up to three antennae, sometimes with four N-acetylhexosamine residues in series. There were no major differences between the C. elegans wildtype and hex-5 mutant strains, but the hex-4 mutant strains displayed altered sets of methanol-eluted and PNGase Ar-released pools. In keeping with the specificity of HEX-4, there were more glycans capped with N-acetylgalactosamine in the hex-4 mutants, as compared with isomeric chito-oligomer motifs in the wildtype. Considering that fluorescence microscopy showed that a HEX-4::enhanced GFP fusion protein colocalizes with a Golgi tracker, we conclude that HEX-4 plays a significant role in late-stage Golgi processing of N-glycans in C. elegans. Furthermore, finding more "parasite-like" structures in the model worm may facilitate discovery of glycan-processing enzymes occurring in other nematodes.
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- Wojcik-Gargula, A., et al.
(author)
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Studies on the behaviour of titanium activation foils during long-term exposure at the JET tokamak
- 2022
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In: Fusion engineering and design. - : Elsevier BV. - 0920-3796 .- 1873-7196. ; 177, s. 113056-
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Journal article (peer-reviewed)abstract
- Titanium activation foils for neutron studies were exposed inside the JET tokamak vessel during the entire 15 months long experimental campaign with deuterium fuelling. Afterwards, it was found that the structure of some foils was only slightly affected, while others were totally or partly disintegrated into dust: flakes and powder. The analyses indicated that defects produced in materials by cutting during the sample preparation eventually lead to the degradation of the titanium crystal structure upon the exposure in JET to neutral particles including hydrogen. In some cases, a passive oxide layer on the foil surface effectively prevented the access of hydrogen, and by this protected the metal against partial or complete transformation into the titanium hydride powder.
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