Browsing by Subject "ARRAY"

Sort by: Order: Results:

Now showing items 1-5 of 5
  • Ronnberg, Bengt; Gustafsson, Ake; Vapalahti, Olli; Emmerich, Petra; Lundkvist, Ake; Schmidt-Chanasit, Jonas; Blomberg, Jonas (2017)
    The recent spread of Zika virus (ZIKV) in the Americas and Asia necessitates an increased preparedness for improved maternal and perinatal health and blood safety. However, serological cross-reactions, especially to Dengue virus (DENV), complicate ZIKV antibody serodiagnosis. A novel "pan-Flavi" suspension multiplex immunoassay (PFSMIA) using 25 antigens, whole virus (WV), non-structural protein 1 (NS1), and envelope (E) proteins, from 7 zoonotic flaviviruses for specific detection of ZIKV and DENV IgM and IgG was developed. Patterns of antibody cross-reactivity, avidity, and kinetics were established in 104 sera from returning travelers with known ZIKV and DENV infections. PFSMIA gave IgM- and IgG-sensitivities for both viruses of 96-100%, compared to an immunofluorescence assay. Main IgM cross-reactions were to NS1, for IgG to the E and WV antigens. Infecting virus yielded reactivity to several antigens of the homologous virus, while cross-reactions tended to occur only to a single antigen from heterologous virus(es). A specificity-enhancing computer procedure took into account antibody isotype, number of antibody-reactive antigens per virus, avidity, average degree of cross-reactivity to heterologous flavivirus antigens, and reactivity changes in serial sera. It classified all 50 cases correctly. Applied to sera from 200 pregnant women and 173 blood donors from Sweden, one blood donor was found ZIKV NS1 IgM positive, and another as ZIKV NS1 IgG positive. These samples did not react with other ZIKV antigens and were thereby judged as false-positives. PFSMIA provided sensitive and specific ZIKV and DENV serology, warranting high-throughput serological surveillance and a minimized need for laborious and expensive virus neutralization assays.
  • Ritari, Jarmo; Hultman, Jenni; Fingerroos, Rita; Tarkkanen, Jussi; Pullat, Janne; Paulin, Lars; Kivi, Niina; Auvinen, Petri; Auvinen, Eeva (2012)
  • Nordlund, Jessica; Backlin, Christofer L.; Zachariadis, Vasilios; Cavelier, Lucia; Dahlberg, Johan; Ofverholm, Ingegerd; Barbany, Gisela; Nordgren, Ann; Overnas, Elin; Abrahamsson, Jonas; Flaegstad, Trond; Heyman, Mats M.; Jonsson, Olafur G.; Kanerva, Jukka; Larsson, Rolf; Palle, Josefine; Schmiegelow, Kjeld; Gustafsson, Mats G.; Lonnerholm, Gudmar; Forestier, Erik; Syvanen, Ann-Christine (2015)
  • Inbal, Asaf; Cristea-Platon, Tudor; Ampuero, Jean-Paul; Hillers, Gregor; Agnew, Duncan; Hough, Susan E. (2018)
  • Hillers, Gregor; Vuorinen, Tommi A.T.; Uski, Marja; Kortström, Jari; Mäntyniemi, Päivi; Tiira, Timo; Malin, Peter E.; Saarno, Tero (2020)
    A seismic network was installed in Helsinki, Finland to monitor the response to an similar to 6-kilometer-deep geothermal stimulation experiment in 2018. We present initial results of multiple induced earthquake seismogram and ambient wavefield analyses. The used data are from parts of the borehole network deployed by the operating St1 Deep Heat Company, from surface broadband sensors and 100 geophones installed by the Institute of Seismology, University of Helsinki, and from Finnish National Seismic Network stations. Records collected in the urban environment contain many signals associated with anthropogenic activity. This results in time- and frequency-dependent variations of the signal-to-noise ratio of earthquake records from a 260-meter-deep borehole sensor compared to the combined signals of 24 collocated surface array sensors. Manual relocations of similar to 500 events indicate three distinct zones of induced earthquake activity that are consistent with the three clusters of seismicity identified by the company. The fault-plane solutions of 14 selected ML 0.6-1.8 events indicate a dominant reverse-faulting style, and the associated SH radiation patterns appear to control the first-order features of the macroseismic report distribution. Beamforming of earthquake data from six arrays suggests heterogeneous medium properties, in particular between the injection site and two arrays to the west and southwest. Ambient-noise cross-correlation functions reconstruct regional surface-wave propagation and path-dependent body-wave propagation. A 1D inversion of the weakly dispersive surface waves reveals average shear-wave velocities around 3.3 km/s below 20 m depth. Consistent features observed in relative velocity change time series and in temporal variations of a proxy for wavefield partitioning likely reflect the medium response to the stimulation. The resolution properties of the obtained data can inform future monitoring strategies and network designs around natural laboratories.