Structural Insight into Archaic and Alternative Chaperone-Usher Pathways Reveals a Novel Mechanism of Pilus Biogenesis

AVZ is supported by the Finnish Academy (grants 140959 and 273075; http://sciencenordic.com/partner/academy-finland) and Sigrid Juselius Foundation (grant 2014; www.sigridjuselius.fi/foundation). SMis supported by the Wellcome Trust (Senior Investigator Award 100280, Programme grant 079819; http://www.wellcome.ac.uk) The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Changing climate and outbreaks of forest pest insects in a cold northern country, Finland

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Bacterial Surface Appendages Strongly Impact Nanomechanical and Electrokinetic Properties of Escherichia coli Cells Subjected to Osmotic Stress

The physicochemical properties and dynamics of bacterial envelope, play a major role in bacterial activity. In this study, the morphological, nanomechanical and electrohydrodynamic properties of Escherichia coli K-12 mutant cells were thoroughly investigated as a function of bulk medium ionic strength using atomic force microscopy (AFM) and electrokinetics (electrophoresis). Bacteria were differing according to genetic alterations controlling the production of different surface appendages (short and rigid Ag43 adhesins, longer and more flexible type 1 fimbriae and F pilus). From the analysis of the spatially resolved force curves, it is shown that cells elasticity and turgor pressure are not only depending on bulk salt concentration but also on the presence/absence and nature of surface appendage. In 1 mM KNO3, cells without appendages or cells surrounded by Ag43 exhibit large Young moduli and turgor pressures (∼700–900 kPa and ∼100–300 kPa respectively). Under similar ionic strength condition, a dramatic ∼50% to ∼70% decrease of these nanomechanical parameters was evidenced for cells with appendages. Qualitatively, such dependence of nanomechanical behavior on surface organization remains when increasing medium salt content to 100 mM, even though, quantitatively, differences are marked to a much smaller extent. Additionally, for a given surface appendage, the magnitude of the nanomechanical parameters decreases significantly when increasing bulk salt concentration. This effect is ascribed to a bacterial exoosmotic water loss resulting in a combined contraction of bacterial cytoplasm together with an electrostatically-driven shrinkage of the surface appendages. The former process is demonstrated upon AFM analysis, while the latter, inaccessible upon AFM imaging, is inferred from electrophoretic data interpreted according to advanced soft particle electrokinetic theory. Altogether, AFM and electrokinetic results clearly demonstrate the intimate relationship between structure/flexibility and charge of bacterial envelope and propensity of bacterium and surface appendages to contract under hypertonic conditions

Performance analysis of <em>m</em>MCSK-<em>m</em>MFSK modulation variants with comparative discussion

Abstract This thesis deals with the fascinating subject of the design of digital communication systems - or more precisely one topic therein, i.e., modulation. Modulation and its counterpart demodulation are the means of making the information ride the beast of a wireless radio channel. The introduction of mMFSK and amMFSK generated ideas of applying the approach to other modulation methods. The straightforward extension was to apply the method to CSK modulation to introduce mMCSK modulation. The analysis shows that due to the orthogonality of the signaling waveforms of mMCSK (with Walsh codes) and mMFSK, the same performance is achieved for modulation methods with the same modulation alphabet. But with CSK it is rather easy to construct non-orthogonal signaling waveforms. Hence, the thesis also gives analytical results for non-orthogonal mMCSK and especially considers (as an example) the use of Gold and Kasami codes. The results indicate that the best choice of codes for a non-coherent mMCSK system is the orthogonal code family, which is a rather intuitive result. However, for a coherent mMCSK system, better performance could be achieved with non-orthogonal codes. Given that we can construct a code set where the cross-correlation between the codes in the family is negative (&#961;i,j&#60;0), performance improvement compared to the orthogonal code family is achieved. The results show that, for instance, a 0.5 dB performance improvement in the AWGN channel can be achieved by using a specifically constructed set of Kasami codes as the basis functions in the modulation. The thesis also presents the performance analysis results of mMCSK in a flat Rayleigh fading channel. To further enlarge the modulation alphabet sizes (with the price of larger spectrum usage) it was realized that combining the mMFSK and mMCSK would be an interesting choice. The mMCSK-mMFSK modulation was hence introduced, which can be viewed as the main contribution of this thesis. A method to analyze this two-component modulation was developed and the performance analyses give results for mMCSK-mMFSK modulation in AWGN and flat Rayleigh fading channels for both coherent and non-coherent receivers. The performance was also assessed with orthogonal and non-orthogonal code constructs. Moreover, an antipodal extension of the mMCSK-mMFSK modulation was introduced with the analysis of the performance. A third contribution of the thesis was to introduce the mPPM modulation method following the mMFSK principles. The performance results obtained in the mMCSK can also be applied to these modulation formats in certain scenarios. PPM modulation has been widely suggested to be used in UWB systems. In UWB systems, the means to adapt the data rate is the use of pulse repetition. Hence, the performance analysis of the mPPM modulation methods with pulse repetition and a non-coherent receiver was computed. The performance of pulse repetition in impulsive interference was also computed.Tiivistelmä Tässä väitöskirjatyössä tarkastellaan tietoliikennejärjestelmän suunnitteluun liittyvää osa-aluetta modulaatiomenetelmä. Modulaatio ja sen vastinpari demodulaatio ovat mekanismit, joiden avulla siirrettävä tieto saatetaan muotoon, jolla se voidaan siirtää radiokanavassa. mMFSK ja amMFSK modulaatiomenetelmien kehittäminen loi pohjan, jota lähdettiin soveltamaan myös muihin modulaatiotekniikoihin. Suoritetut matemaattiset analyysit osoittavat, että samalle modulaatioaakkoston koolle mMCSK (käyttäen Walsh-koodeja) ja mMFSK saavuttavat saman suorituskyvyn olettaen modulaatioiden olevan ortogonaalisia. CSK-tekniikalla on kuitenkin helppo rakentaa koodeja, jotka ovat epäortogonaalisia. Väitöskirjassa analysoidaan myös muutamia tapauksia epaortogonaaliselle mMCSK:lle, jossa esimerkinomaisesti tarkastellaan Gold- ja Kasami-koodien käyttöä. Tulokset osoittavat, että epäkoherentille mMCSK:lle paras valinta koodiperheeksi on ortogonaalinen koodiperhe, joka tuloksena on myös intuitiivinen. Koherentille mMCSK:lle voidaan kuitenkin rakentaa epäortogonaalisia koodikonstruktioita, joissa koodien välinen ristikorrelaatio on negatiivinen ja tällöin saavutetaan suorituskyvyn parantumista ortogonaaliseen koodiperheeseen verattuna. Tulokset Gold- ja Kasami-koodeille AWGN-kanavassa osoittavat, että n. 0.5 dB suorituskyvyn paraneminen on saavutettavissa. Työssä johdetaan myös analyyttiset tulokset vastaaville tapauksille Rayleigh-häipyvässä kanavassa. Tutkittaessa mMCSK- ja mMFSK-modulaatioita, huomattiin, että yhdistämällä nämä kaksi voidaan saavuttaa erittäin suuria modulaatioaakkostoja. Hintana on suurempi spektrin käyttö. mMCSK-mMFSK-modulaation kehittämistä voidaan pitää tämän työn päätuloksena. Työssä kehitetään likimääräinen menetelmä tämän kaksi-komponenttisen modulaation suorituskyvyn analysoimiseksi. Tuloksina esitetään modulaatiomenetelmän suorituskyky sekä AWGN- että Rayleigh-häipyvässä kanavassa. Suorituskykytuloksia esitetään myös epäortogonaalisille koodikonstruktioille. Lisäksi kehitettiin antipodaalinen laajennus mMCSK-mMFSK-modulaatiosta ja suoritettiin suorituskykyanalyysi AWGN-kanavassa. Työn kolmantena tuloksena esitetään mPPM-modulaatiomenetelmä hyödyntäen mMCSK-modulaation periaatteita. mMCSK-suorituskykyanalyysia voidaan tietyin ehdoin soveltaa myös näihin modulaatiomenetelmiin, joiden käyttöä esitetään usein ultralaajakaistajärjestelmissä (UWB). UWB-järjestelmissä datanopeutta säädetään usein pulssin toistoa käyttämällä. Työssä johdetaan suorityskykytulokset epäkoherentille mPPM-vastaanottimelle myös pulssintoiston yhteydessä. Lisäksi johdettiin suorituskykylausekkeet ko. modulaatioille impulsiivisen häiriön läsnäollessa

6G white paper on validation and trials for verticals towards 2030’s

Executive Summary This white paper discusses the different business verticals that are expected to gain productivity enhancements with the introduction of B5G/6G wireless services. It is evident that wireless offers benefits when the use case exhibits mobility, and requires nomadic behavior or flexibility. In some situations, costs may favor wireless solutions (e.g. retrofitting). In many cases, however, a fiber optic solution remains a viable approach. Based on revenue expansion potential and the most opportunity-rich verticals, we have selected seven vertical businesses and future software-based testing for discussion: industry4.0; future mobility; eHealth; energy; finance and banking; public safety; and agribusiness. We describe the drivers in the respective verticals and the expected change. We also highlight the features within verticals that may require 6G capabilities and make an initial attempt to provide some key performance and value indicators for vertical businesses, highlighting the divergence in requirements to be experienced in the 2030s. We conclude the discussion by proposing some guidelines for trialing and validation activities within verticals to agree golden references that set a reference baseline against which any system provider can test their solutions. Finally, out of the white paper, we have formulated critical research questions to be answered during this decade to provide the foreseen vertical-specific solutions