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  • Qi, Lu; Vogel, Alexander L.; Esmaeilirad, Sepideh; Cao, Liming; Zheng, Jing; Jaffrezo, Jean-Luc; Fermo, Paola; Kasper-Giebl, Anne; Dällenbach, Kaspar; Chen, Mindong; Ge, Xinlei; Baltensperger, Urs; Prevot, Andre S. H.; Slowik, Jay G. (2020)
    The aerosol mass spectrometer (AMS), combined with statistical methods such as positive matrix factorization (PMF), has greatly advanced the quantification of primary organic aerosol (POA) sources and total secondary organic aerosol (SOA) mass. However, the use of thermal vaporization and electron ionization yields extensive thermal decomposition and ionization-induced fragmentation, which limit chemical information needed for SOA source apportionment. The recently developed extractive electrospray ionization time-of-flight mass spectrometer (EESI-TOF) provides mass spectra of the organic aerosol fraction with a linear response to mass and no thermal decomposition or ionization-induced fragmentation. However, the costs and operational requirements of online instruments make their use impractical for long-term or spatially dense monitoring applications. This challenge was overcome for AMS measurements by measuring re-nebulized water extracts from ambient filter samples. Here, we apply the same strategy for EESI-TOF measurements of 1 year of 24 h filter samples collected approximately every fourth day throughout 2013 at an urban site. The nebulized water extracts were measured simultaneously with an AMS. The application of positive matrix factorization (PMF) to EESI-TOF spectra resolved seven factors, which describe water-soluble OA: less and more aged biomass burning aerosol (LABB(EESI) and MABB(EESI), respectively), cigarette-smoke-related organic aerosol, primary biological organic aerosol, biogenic secondary organic aerosol, and a summer mixed oxygenated organic aerosol factor. Seasonal trends and relative contributions of the EESI-TOF OA sources were compared with AMS source apportionment factors, measured water-soluble ions, cellulose, and meteorological data. Cluster analysis was utilized to identify key factor-specific ions based on PMF. Both LABB and MABB contribute strongly during winter. LABB is distinguished by very high signals from C6H10O5 (levoglucosan and isomers) and C8H12O6, whereas MABB is characterized by a large number of CxHyOz and CxHyOzN species of two distinct populations: one with low H : C and high O : C and the other with high H : C and low O : C. Two oxygenated summertime SOA sources were attributed to terpene-derived biogenic SOA, a major summertime aerosol source in central Europe. Furthermore, a primary biological organic aerosol factor was identified, which was dominated by plant-derived fatty acids and correlated with free cellulose. The cigarette-smoke-related factor contained a high contribution of nicotine and high abundance of organic nitrate ions with low m/z.
  • Cecchetti, Cristina; Strauss, Jannik; Stohrer, Claudia; Naylor, Claire; Pryor, Edward; Hobbs, Jeanette; Tanley, Simon; Goldman, Adrian; Byrne, Bernadette (2021)
    Membrane proteins have a range of crucial biological functions and are the target of about 60% of all prescribed drugs. For most studies, they need to be extracted out of the lipid-bilayer, e.g. by detergent solubilisation, leading to the loss of native lipids, which may disturb important protein-lipid/bilayer interactions and thus functional and structural integrity. Relipidation of membrane proteins has proven extremely successful for studying challenging targets, but the identification of suitable lipids can be expensive and laborious. Therefore, we developed a screen to aid the high-throughput identification of beneficial lipids. The screen covers a large lipid space and was designed to be suitable for a range of stability assessment methods. Here, we demonstrate its use as a tool for identifying stabilising lipids for three membrane proteins: a bacterial pyrophosphatase (Tm-PPase), a fungal purine transporter (UapA) and a human GPCR (A(2A)R). A(2A)R is stabilised by cholesteryl hemisuccinate, a lipid well known to stabilise GPCRs, validating the approach. Additionally, our screen also identified a range of new lipids which stabilised our test proteins, providing a starting point for further investigation and demonstrating its value as a novel tool for membrane protein research. The pre-dispensed screen will be made commercially available to the scientific community in future and has a number of potential applications in the field.
  • Hu, Man; Lehtonen, Aleksi; Minunno, Francesco; Mäkelä, Annikki (2020)
    Tree structure equations derived from pipe model theory (PMT) are well-suited to estimate biomass allocation in Scots pine (Pinus sylvestrisL.) and Norway spruce (Picea abies[L.] Karst.). However, age dependence of parameters should be accounted for when applying the equations.
  • Laursen, Karsten; Moller, Anders Pape; Haugaard, Lars; Öst, Markus; Vainio, Jouni (2019)
    Capital breeders, such as the eider duck Somateria mollissima, accumulate resources before the start of breeding. Eiders preferentially feed on blue mussels Mytilus edulis to build up body condition during winter. We explored how body condition and gizzard mass of wintering eiders relate to mussel quality and quantity, winter climate and body condition of females at the breeding grounds. Body condition during winter (defined as scaled body mass index) of eiders increased during winter and the magnitude of the effect depended on age and mussel quality. Gizzard mass of eiders increased during winter with effects of mussel quality, mussel stocks and sex. Body condition in winter of adult females increased from the first half of January to the second half of February on average by 1.5%, equal to c. 96 g. During the same period gizzard mass of adult females increased by 12.2%, i.e., a nearly ten-fold increase compared to that observed in body condition in winter. Body condition of females at the breeding grounds in Finland (defined as body condition at hatching) was significantly positively correlated with gizzard mass in winter, but not significantly correlated with body condition in winter. Thus, eiders allocate body reserves to increase gizzard mass but less so to increase body condition in winter. This can be considered an adaptive migratory strategy of these eiders, whereby large winter (pre-migratory) gizzards increase food processing capacity, making it possible for eiders to arrive at the breeding grounds with superior body condition and a high reproductive potential.
  • Jussila, Vilho; Fälth, Billy; Mäntyniemi, Päivi; Voss, Peter H.; Lund, Björn; Fülöp, Ludovic (2021)
    We present a modeling technique for generating synthetic ground motions, aimed at earthquakes of design significance for critical structures and ground motions at distances corresponding to the engineering near field, in which real data are often missing. We use dynamic modeling based on the finite-difference approach to simulate the rupture process within a fault, followed by kinematic modeling to generate the ground motions. The earthquake source ruptures were modeled using the 3D distinct element code (Itasca, 2013). We then used the complete synthetic program by Spudich and Xu (2002) to simulate the propagation of seismic waves and to obtain synthetic ground motions. In this work, we demonstrate the method covering the frequency ranges of engineering interests up to 25 Hz and quantify the differences in ground motion generated. We compare the synthetic ground motions for distances up to 30 km with a ground-motion prediction equation, which synthesizes the expected ground motion and its randomness based on observations. The synthetic ground motions can be used to supplement observations in the near field for seismic hazard analysis. We demonstrate the hybrid approach to one critical site in the Fennoscandian Shield, northern Europe.
  • Jussila, Vilho; Fälth, Billy; Mäntyniemi, Päivi; Voss, Peter H.; Lund, Björn; Fülöp, Ludovic (2021)
    We present a modeling technique for generating synthetic ground motions, aimed at earthquakes of design significance for critical structures and ground motions at distances corresponding to the engineering near field, in which real data are often missing. We use dynamic modeling based on the finite-difference approach to simulate the rupture process within a fault, followed by kinematic modeling to generate the ground motions. The earthquake source ruptures were modeled using the 3D distinct element code (Itasca, 2013). We then used the complete synthetic program by Spudich and Xu (2002) to simulate the propagation of seismic waves and to obtain synthetic ground motions. In this work, we demonstrate the method covering the frequency ranges of engineering interests up to 25 Hz and quantify the differences in ground motion generated. We compare the synthetic ground motions for distances up to 30 km with a ground-motion prediction equation, which synthesizes the expected ground motion and its randomness based on observations. The synthetic ground motions can be used to supplement observations in the near field for seismic hazard analysis. We demonstrate the hybrid approach to one critical site in the Fennoscandian Shield, northern Europe.
  • Vuorio, Joni; Vattulainen, Ilpo; Martinez-Seara, Hector (2017)
    Hyaluronan is a polyanionic, megadalton-scale polysaccharide, which initiates cell signaling by interacting with several receptor proteins including CD44 involved in cell-cell interactions and cell adhesion. Previous studies of the CD44 hyaluronan binding domain have identified multiple widespread residues to be responsible for its recognition capacity. In contrast, the X-ray structural characterization of CD44 has revealed a single binding mode associated with interactions that involve just a fraction of these residues. In this study, we show through atomistic molecular dynamics simulations that hyaluronan can bind CD44 with three topographically different binding modes that in unison define an interaction fingerprint, thus providing a plausible explanation for the disagreement between the earlier studies. Our results confirm that the known crystallographic mode is the strongest of the three binding modes. The other two modes represent metastable configurations that are readily available in the initial stages of the binding, and they are also the most frequently observed modes in our unbiased simulations. We further discuss how CD44, fostered by the weaker binding modes, diffuses along HA when attached. This 1D diffusion combined with the constrained relative orientation of the diffusing proteins is likely to influence the aggregation kinetics of CD44. Importantly, CD44 aggregation has been suggested to be a possible mechanism in CD44-mediated signaling.
  • Jolma, Arttu; Zhang, Jilin; Mondragon, Estefania; Morgunova, Ekaterina; Kivioja, Teemu; Laverty, Kaitlin U.; Yin, Yimeng; Zhu, Fangjie; Bourenkov, Gleb; Morris, Quaid; Hughes, Timothy R.; Maher III, Louis James; Taipale, Jussi (2020)
    RNA-binding proteins (RBPs) regulate RNA metabolism at multiple levels by affecting splicing of nascent transcripts, RNA folding, base modification, transport, localization, translation, and stability. Despite their central role in RNA function, the RNA-binding specificities of most RBPs remain unknown or incompletely defined. To address this, we have assembled a genome-scale collection of RBPs and their RNA-binding domains (RBDs) and assessed their specificities using high-through-put RNA-SELEX (HTR-SELEX). Approximately 70% of RBPs for which we obtained a motif bound to short linear sequenc-es, whereas similar to 30% preferred structured motifs folding into stem-loops. We also found that many RBPs can bind to multiple distinctly different motifs. Analysis of the matches of the motifs in human genomic sequences suggested novel roles for many RBPs. We found that three cytoplasmic proteins-ZC3H12A, ZC3H12B, and ZC3H12C-bound to motifs resembling the splice donor sequence, suggesting that these proteins are involved in degradation of cytoplasmic viral and/or unspliced transcripts. Structural analysis revealed that the RNA motif was not bound by the conventional C3H1 RNA-binding domain of ZC3H12B. Instead, the RNA motif was bound by the ZC3H12B's PilT N terminus (PIN) RNase domain, revealing a po-tential mechanism by which unconventional RBDs containing active sites or molecule-binding pockets could interact with short, structured RNA molecules. Our collection containing 145 high-resolution binding specificity models for 86 RBPs is the largest systematic resource for the analysis of human RBPs and will greatly facilitate future analysis of the various bi-ological roles of this important class of proteins.
  • Frege, Carla; Bianchi, Federico; Molteni, Ugo; Trostl, Jasmin; Junninen, Heikki; Henne, Stephan; Sipilä, Mikko; Herrmann, Erik; Rossi, Michel J.; Kulmala, Markku; Hoyle, Christopher R.; Baltensperger, Urs; Dommen, Josef (2017)
    The ion composition at high altitude (3454 m a.s.l.) was measured with an atmospheric pressure interface time-of-flight mass spectrometer (APi-TOF) during a period of 9 months, from August 2013 to April 2014. The negative mass spectra were dominated by the ions of sulfuric, nitric, malonic, and methanesulfonic acid (MSA) as well as SO5. The most prominent positive ion peaks were from amines. The other cations were mainly organic compounds clustered with a nitrogen-containing ion, which could be either NH4+ or an aminium. Occasionally the positive spectra were characterized by groups of compounds each differing by a methylene group. In the negative spectrum, sulfuric acid was always observed during clear sky conditions following the diurnal cycle of solar irradiation. On many occasions we also saw a high signal of sulfuric acid during nighttime when clusters up to the tetramer were observed. A plausible reason for these events could be evaporation from particles at low relative humidity. A remarkably strong correlation between the signals of SO5 and CH3SO3- was observed for the full measurement period. The presence of these two ions during both the day and the night suggests a non-photochemical channel of formation which is possibly linked to halogen chemistry. Halogenated species, especially Br- and IO3-, were frequently observed in air masses that originated mainly from the Atlantic Ocean and occasionally from continental areas based on back trajectory analyses. We found I2O5 clustered with an ion, a species that was proposed from laboratory and modeling studies. All halogenated ions exhibited an unexpected diurnal behavior with low values during daytime. New particle formation (NPF) events were observed and characterized by (1) highly oxygenated molecules (HOMs) and low sulfuric acid or (2) ammonia-sulfuric acid clusters. We present characteristic spectra for each of these two event types based on 26 nucleation episodes. The mass spectrum of the ammonia-sulfuric acid nucleation event compares very well with laboratory measurements reported from the CLOUD chamber. A source receptor analysis indicates that NPF events at the Jungfraujoch take place within a restricted period of time of 24-48 h after air masses have had contact with the boundary layer. This time frame appears to be crucial to reach an optimal oxidation state and concentration of organic molecules necessary to facilitate nucleation.
  • Elminen, Tuija; Zwingmann, Horst; Kaakinen, Anu (2018)
    Sheared sedimentary clay was found in a faulted fracture in crystalline bedrock in a tunnelling site at 60 m depth in southern Finland. Brittle faults are numerous in the Fennoscandian Palaeoproterozoic bedrock, but only some of them have relative age constraints, while absolute ages are nearly lacking. Sedimentary rocks altogether are uncommon in Finland and only sparsely dated by micropaleontological studies. This study reports K-Ar data of fresh, non-weathered authigenic illite and constrains a time framework for the local faulting and sedimentation. The Neoproterozoic Tonian to Cryogenian ages derived from the grains in diminishing grain-size order are c. 967, 947, 809 and 697 Ma. Results indicate that the formation of the extension fracture is related to the collapse of Sveconorwegian orogeny c. 1000 Ma; clay and mature quartz sand were deposited in this extension fracture in shallow water in an intracratonic basin followed by early diagenetic processes and neocrystallization of illite around 967-947 Ma. The Neoproterozoic 1000-700 Ma sedimentation documented in this study is rare in the Fennoscandian shield as a whole. Neocrystallization of authigenic illite in the finest 0.4 and <0.1 pm fractions c. 809-697 Ma ago is interpreted as resulting from reactivation in the fault due to the continental break-up on the western side of the craton as documented by arenite crosscutting relationships. The younger ages may also be attributed to a Caledonian thermal overprint ca. 410 Ma ago that would influence the 967 Ma age if sufficient thermal energy had been present.
  • Kwiatek, Grzegorz; Saarno, Tero; Ader, Thomas; Bluemle, Felix; Bohnhoff, Marco; Chendorain, Michael; Dresen, Georg; Heikkinen, Pekka; Kukkonen, Ilmo; Leary, Peter; Leonhardt, Maria; Malin, Peter; Martínez-Garzón, Patricia; Passmore, Kevin; Passmore, Paul; Valenzuela, Sergio; Wollin, Christopher (2019)
    We show that near–real-time seismic monitoring of fluid injection allowed control of induced earthquakes during the stimulation of a 6.1-km-deep geothermal well near Helsinki, Finland. A total of 18,160 m3 of fresh water was pumped into crystalline rocks over 49 days in June to July 2018. Seismic monitoring was performed with a 24-station borehole seismometer network. Using near–real-time information on induced-earthquake rates, locations, magnitudes, and evolution of seismic and hydraulic energy, pumping was either stopped or varied—in the latter case, between well-head pressures of 60 and 90 MPa and flow rates of 400 and 800 liters/min. This procedure avoided the nucleation of a project-stopping magnitude MW 2.0 induced earthquake, a limit set by local authorities. Our results suggest a possible physics-based approach to controlling stimulation-induced seismicity in geothermal projects.
  • Lehti, Timo; Pajunen, Maria; Jokilammi, Anne; Korja, Miikka Joojakim; Lilie, Hauke; Vettenranta, Kim; Finne, Jukka (2021)
    Polysialic acid, an abundant cell surface component of the developing nervous system, which declines rapidly postnatally to virtual absence in the majority of adult tissues, is highly expressed in some malignant tumors including neuroblastoma. We found that the binding of a noncatalytic endosialidase to polysialic acid causes internalization of the complex from the surface of neuroblastoma kSK-N-SH cells, a subline of SK-N-SH, and leads to a complete relocalization of polysialic acid to the intracellular compartment. The binding and uptake of the endosialidase is polysialic acid-dependent as it is inhibited by free excess ligand or removal of polysialic acid by active endosialidase, and does not happen if catalytic endosialidase is used in place of inactive endosialidase. Afusion protein composed of the noncatalytic endosialidase and the cytotoxic portion of diphtheria toxin was prepared to investigate whether the cellular uptake observed could be used for the specific elimination of polysialic acid-containing cells. The conjugate toxin was found to be toxic to polysialic acid-positive kSKN-SH with an IC50 of 1.0 nmol/L. Replacing the noncatalytic endosialidase with active endosialidase decreased the activity to the level of nonconjugated toxin. Normal nonmalignant cells were selectively resistant to the toxin conjugate. The results demonstrate that noncatalytic endosialidase induces a quantitative removal and cellular uptake of polysialic acid from the cell surface which, by conjugation with diphtheria toxin fragment, can be exploited for the selective elimination of polysialic acid-containing tumor cells.
  • Escudero, Javier; Heredia-Soto, Victoria; Wang, Yinyin; Ruiz, Patricia; Hu, Yingying; Gallego, Alejandro; Pozo-Kreilinger, Jose Juan; Martinez-Marin, Virginia; Berjon, Alberto; Ortiz-Cruz, Eduardo; Bernabeu, Daniel; Feliu, Jaime; Tang, Jing; Redondo, Andres; Mendiola, Marta (2021)
    Background Eribulin has shown antitumour activity in some soft tissue sarcomas (STSs), but it has only been approved for advanced liposarcoma (LPS). Methods In this study, we evaluated the effect of eribulin on proliferation, migration and invasion capabilities in LPS, leiomyosarcoma (LMS) and fibrosarcoma (FS) models, using both monolayer (2D) and three-dimensional (3D) spheroid cell cultures. Additionally, we explored combinations of eribulin with other drugs commonly used in the treatment of STS with the aim of increasing its antitumour activity. Results Eribulin showed activity inhibiting proliferation, 2D and 3D migration and invasion in most of the cell line models. Furthermore, we provide data that suggest, for the first time, a synergistic effect with ifosfamide in all models, and with pazopanib in LMS as well as in myxoid and pleomorphic LPS. Conclusions Our results support the effect of eribulin on LPS, LMS and FS cell line models. The combination of eribulin with ifosfamide or pazopanib has shown in vitro synergy, which warrants further clinical research.
  • Saponaro, Giulia; Kolmonen, Pekka; Sogacheva, Larisa; Rodriguez, Edith; Virtanen, Timo; De Leeuw, Gerrit (2017)
    Retrieved from the Moderate Resolution Imaging Spectroradiometer (MODIS) on-board the Aqua satellite, 12 years (2003-2014) of aerosol and cloud properties were used to statistically quantify aerosol-cloud interaction (ACI) over the Baltic Sea region, including the relatively clean Fennoscandia and the more polluted central-eastern Europe. These areas allowed us to study the effects of different aerosol types and concentrations on macro-and microphysical properties of clouds: cloud effective radius (CER), cloud fraction (CF), cloud optical thickness (COT), cloud liquid water path (LWP) and cloud-top height (CTH). Aerosol properties used are aerosol optical depth (AOD), Angstrom exponent (AE) and aerosol index (AI). The study was limited to low-level water clouds in the summer. The vertical distributions of the relationships between cloud properties and aerosols show an effect of aerosols on low-level water clouds. CF, COT, LWP and CTH tend to increase with aerosol loading, indicating changes in the cloud structure, while the effective radius of cloud droplets decreases. The ACI is larger at relatively low cloud-top levels, between 900 and 700 hPa. Most of the studied cloud variables were unaffected by the lower-tropospheric stability (LTS), except for the cloud fraction. The spatial distribution of aerosol and cloud parameters and ACI, here defined as the change in CER as a function of aerosol concentration for a fixed LWP, shows positive and statistically significant ACI over the Baltic Sea and Fennoscandia, with the former having the largest values. Small negative ACI values are observed in central-eastern Europe, suggesting that large aerosol concentrations saturate the ACI.
  • Vanninen, Paula; Östin, Anders; Beldowski, Jacek; Pedersen, Erik A.; Söderström, Martin; Szubska, Marta; Grabowski, Milosz; Siedlewicz, Grzegorz; Czub, Michal; Popiel, Stanislaw; Dziedzic, Daniel; Jakacki, Jaromir; Paczek, Bartlomiej; Nawala, Jakub (2020)
    About 50 000 tons of chemical weapons (CW) were dumped to the Baltic Sea after the Second World War. Munitions are located in the deep areas of the Baltic Sea, and there they act as a point source of contamination to the ecosystem. Corroded munitions release chemical warfare agents (CWAs) to nearby water and sediments. In this study we investigated known dumpsites (Bornholm, Gotland and Gdansk Deep) and dispersed chemical munitions, to evaluate the extent of contamination of nearby sediments, as well as to assess the degradation process of released CWA. It was found that CWA-related phenylarsenic chemicals (Clark I, Clark II and Adamsite) and sulfur mustard are released to the sediments and undergo environmental degradation to chemicals, of which some remain toxic. The extent of pollution of released CWAs and their corresponding degradation products reaches more than 250 m from the CW objects, and seem to follow a power curve decrease of concentration from the source. Bornholm Deep is characterised with the highest concentration of CWAs in sediments, but occasional concentration peaks are also observed in the Gdansk Deep and close to dispersed munitions. Detailed investigation of spreading pattern show that the range of pollution depends on bottom currents and topography.
  • Cano-Fernandez, Hugo; Jernvall, Jukka (2022)
    Objectives The occlusal surface of many mammalian teeth has grooves that have been collectively called crenulations. The evolutionary significance of this trait is unknown, but it has been associated with a hard diet. It has not been explained, however, why crenulated molars may present an increased mechanical resistance. The objective of this study was to determine whether a crenulated surface dissipate mechanical stress more efficiently than a smooth one. Materials and methods Using mu CT scans we built 3D models of lower second molars from Homo, Pan, Gorilla, and Pongo. The crenulated models from Homo and Pongo were modified to remove crenulations. Finite element analysis was used to determine the distribution of mechanical stress in all the models when a vertical force was applied. Results The results show that crenulated molars have a distinctive pattern of mechanical stress, namely the stress is higher in the valleys than in the crests of the crenulations. In non-crenulated molars, mechanical stress is more homogeneously distributed. Highly crenulated molars of orangutans show the smallest values of mean stress among the compared species. Artificially removing crenulations results in more homogeneous distribution of stresses and increased mean stress values. Conclusions Molar crenulations may increase molar resistance by canalizing mechanical stress from the tip to the base of the cusps. The overall cusp shape also influences the distribution of stress. This mechanism may be a functional hypothesis to explain the association between crenulated molars and mechanically demanding diets.
  • Lan, Hangzhen; Holopainen, Jani; Hartonen, Kari; Jussila, Matti; Ritala, Mikko; Riekkola, Marja-Liisa (2019)
    Comprehensive and time-dependent information (e.g., chemical composition, concentration) of volatile organic compounds (VOCs) in atmospheric, indoor, and breath air is essential to understand the fundamental science of the atmosphere, air quality, and diseases diagnostic. Here, we introduced a fully automated online dynamic in-tube extraction (ITEX)-gas chromatography/mass spectrometry (GC/MS) method for continuous and quantitative monitoring of VOCs in air. In this approach, modified Cycle Composer software and a PAL autosampler controlled and operated the ITEX preconditioning, internal standard (ISTD) addition, air sampling, and ITEX desorption sequentially to enable full automation. Air flow passed through the ITEX with the help of an external pump, instead of plunger up-down strokes, to allow larger sampling volumes, exhaustive extraction, and consequently lower detection limits. Further, in order to evaluate the ITEX system stability and to develop the corresponding quantitative ITEX method, two laboratory-made permeation systems (for standard VOCs and ISTD) were constructed. The stability and suitability of the developed system was validated with a consecutive 19 day atmospheric air campaign under automation. By using an electrospun polyacrylonitrile nanofibers packed ITEX, selective extraction of some VOCs and durability of over 1500 extraction and desorption cycles were achieved. Especially, the latter step is critically important for on-site long-term application at remote regions. This ITEX method provided 2-3 magnitudes lower quantitation limits than the headspace dynamic ITEX method and other needle trap methods. Our results proved the excellence of the fully automated online dynamic ITEX-GC/MS system for tracking VOCs in the atmospheric air.
  • Tallavaara, Miikka; Pesonen, Petro (2020)
    High-quality palaeoenvironmental proxies and well-preserved archaeological record make Fennoscandia as an excellent area for the studies of long-term human-environment interaction in high-latitude settings. Here, we use palaeoenvironmental data and temporal frequency distributions of 754 shoreline dated hunter-gatherer sites to analyse the relationship between environmental changes and hunter-gatherer population dynamics, mobility, social organisation, and conflicts in the Baltic Sea coast of western Finland. Our results suggest, firstly, that hunter-gatherer population dynamics were strongly influenced by changes in the productivity of terrestrial and marine environments. Secondly, the degree of residential mobility, as indicated by the frequency of house pit sites, was correlated with population size. Thirdly, large villages and large co-residential units were tightly associated with the highest population size and their frequency dropped sharply when population size started to decrease. Fourthly, intensity of conflicts, as indicated by frequency of defensive structures, was the highest slightly after the highest population sizes, when environmental productivity had started to decline. Increased conflicts were probably caused by the imbalance between human population and its resources. Lastly, dramatic population crash (76% within 200 years) occurred just after the intensity peak in conflicts. The crash was partly density dependent (conflicts) and partly density independent phenomenon as it coincided with the onset of the Late Holocene acceleration in the cooling trend in climate. Continuing decline in the environmental productivity during the Late Holocene did not allow hunter-gatherer population to recover from the collapse. All this highlights the importance of environmental forcing on hunter-gatherer populations in northern Europe.
  • Cruz, Cristina D; Wrigstedt, Pauli; Moslova, Karina; Iashin, Vladimir; Mäkkylä, Heidi; Ghemtio, Leo; Heikkinen, Sami; Tammela, Päivi; Perea-Buceta, Jesus Enrique (2021)
    N-aryl-oxazolidinones is a prominent family of antimicrobials used for treating infections caused by clinically prevalent Gram-positive bacteria. Recently, boron-containing compounds have displayed intriguing potential in the antibiotic discovery setting. Herein, we report the unprecedented introduction of a boron-containing moiety such as an aryl boronic acid in the external region of the oxazolidinone structure via a chemoselective acyl coupling reaction. As a result, we accessed a series of analogues with a distal aryl boronic pharmacophore on the oxazolidinone scaffold. We identified that a peripheric linear conformation coupled with freedom of rotation and no further substitution on the external aryl boronic ring, an amido linkage with hydrogen bonding character, in addition to a para-relative disposition between boronic group and linker, are the optimal combination of structural features in this series for antimicrobial activity. In comparison to linezolid, the analogue comprising all those features, compound 20b, displayed levels of antimicrobial activity augmented by an eight-fold to a thirty-two-fold against a panel of Gram-positive strains, and a near one hundred-fold against Escherichia coli JW5503, a Gram-negative mutant strain with a defective efflux capability.
  • Mamali, D.; Mikkilä, J.; Henzing, B.; Spoor, R.; Ehn, M.; Petäjä, T.; Russchenberg, H.; Biskos, G. (2018)
    Long-term measurements of PM2.5 mass concentrations and aerosol particle size distributions from 2008 to 2015, as well as hygroscopicity measurements conducted over one year (2008-2009) at Cabauw, The Netherlands, are compiled here in order to provide a comprehensive dataset for understanding the trends and annual variabilities of the atmospheric aerosol in the region. PM2.5 concentrations have a mean value of 14.4 mu g m(-3) with standard deviation 2.1 mu g m(-3), and exhibit an overall decreasing trend of -0.74 mu g m(-3) year(-1). The highest values are observed in winter and spring and are associated with a shallower boundary layer and lower precipitation, respectively, compared to the rest of the seasons. Number concentrations of particles smaller than 500 nm have a mean of 9.2 x 10(3) particles cm(-3) and standard deviation 4.9x10(3) particles cm(-3), exhibiting an increasing trend between 2008 and 2011 and a decreasing trend from 2013 to 2015. The particle number concentrations exhibit highest values in spring and summer (despite the increased precipitation) due to the high occurrence of nucleation-mode particles, which most likely are formed elsewhere and are transported to the observation station. Particle hygroscopicity measurements show that, independently of the air mass origin, the particles are mostly externally mixed with the more hydrophobic mode having a mean hygroscopic parameter kappa of 0.1 while for the more hydrophilic mode kappa is 0.35. The hygroscopicity of the smaller particles investigated in this work (i.e., particles having diameters of 35 nm) appears to increase during the course of the nucleation events, reflecting a change in the chemical composition of the particles. (C) 2017 Elsevier B.V. All rights reserved.