Browsing by Subject "RANGE"

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  • Zhang, Shuo; Pakarinen, Olli Heikki; Backholm, Matilda; Djurabekova, Flyura; Nordlund, Kai; Keinonen, Juhani; Wang, T.S. (2018)
    In this work, we first simulated the amorphization of crystalline quartz under 50 keV Na-23 ion irradiation with classical molecular dynamics (MD). We then used binary collision approximation algorithms to simulate the Rutherford backscattering spectrometry in channeling conditions (RBS-C) from these irradiated MD cells, and compared the RBS-C spectra with experiments. The simulated RBS-C results show an agreement with experiments in the evolution of amorphization as a function of dose, showing what appears to be (by this measure) full amorphization at about 2.2 eV.atom(-1). We also applied other analysis methods, such as angular structure factor, Wigner-Seitz, coordination analysis and topological analysis, to analyze the structural evolution of the irradiated MD cells. The results show that the atomic-level structure of the sample keeps evolving after the RBS signal has saturated, until the dose of about 5 eV.atom(-1). The continued evolution of the SiO2 structure makes the definition of what is, on the atomic level, an amorphized quartz ambiguous.
  • Korpela, Ilkka (2017)
    Forest inventories comprise observations, models and sampling. Airborne LiDAR has established its role in providing observations of canopy geometry and topography. These data are input for estimation of important forest properties to support forestry-related decision-making. A major deficiency in forest remote sensing is tree species identification. This study examines the option of using multi-footprint airborne LiDAR data. Features of such sensor design exist in recently introduced multispectral laser scanners. The first objective was to acquire radiometrically normalized, multi-footprint (11, 22, 44 and 59 cm) waveform (WF) data that characterize 1064nm backscatter reflectance on the interval scale. The second objective was to analyze and validate the data quality in order to draw the correct conclusions about the effect of footprint size on WFs from natural and man-made targets. The experiment was carried out in Finland. Footprint variation was generated by acquiring data at different flying heights and by adjusting the transmitted power. The LiDAR campaign was successful and the data were of sufficient quality, except for a 1 dB trend due to the atmosphere. Significant findings were made conceming the magnitude of atmospheric losses, the linearity of the amplitude scale and the bandwidth characteristics of the receiver, the stability of the transmitter, the precision of the amplitude data and the transmission losses in canopies and power lines, as well as the response of WF attributes to footprint size in forest canopies. Multi-footprint data are a promising approach although the tree species-specific signatures were weak. (C) 2016 Elsevier Inc. All rights reserved.
  • Multanen, Juhani; Häkkinen, Arja; Kautiainen, Hannu; Ylinen, Jari (2021)
    Background: Neck pain has been associated with weaker neck muscle strength and decreased cervical spine range of motion. However, whether neck muscle strength or cervical spine mobility predict later neck disability has not been demonstrated. In this 16-year prospective study, we investigated whether neck muscle strength and cervical spine mobility are associated with future neck pain and related disability in women pain-free at baseline. Methods: Maximal isometric neck muscle strength and passive range of motion (PROM) of the cervical spine of 220 women (mean age 40, standard deviation (SD) 12 years) were measured at baseline between 2000 and 2002. We conducted a postal survey 16 years later to determine whether any subjects had experienced neck pain and related disability. Linear regression analysis adjusted for age and body mass index was used to determine to what extent baseline neck strength and PROM values were associated with future neck pain and related disability assessed using the Neck Disability Index (NDI). Results: The regression analysis Beta coefficient remained below 0.1 for all the neck strength and PROM values, indicating no association between neck pain and related disability. Of the 149 (68%) responders, mean NDI was lowest (3.3, SD 3.8) in participants who had experienced no neck pain (n = 50), second lowest (7.7, SD 7.1) in those who had experienced occasional neck pain (n = 94), and highest (19.6, SD 22.0) in those who had experienced chronic neck pain (n = 5). Conclusions: This 16-year prospective study found no evidence for an association between either neck muscle strength or mobility and the occurrence in later life of neck pain and disability. Therefore, screening healthy subjects for weaker neck muscle strength or poorer cervical spine mobility cannot be recommended for preventive purposes.
  • Tidenberg, Eeva-Maria; Liukko, Ulla-Maija; Stjernberg, Torsten (2019)
    This atlas is based on information in museum collections, literature, databases and unpublished data. In the last 150 years, the number of bat species in Finland increased from six to thirteen. Of these, five are common and regularly breeding (Eptesicus nilssonii, Myotis brandtii, Myotis daubentonii, Myotis mystacinus, Plecotus auritus), and eight rare (Eptesicus serotinus, Myotis dasycneme, Myotis nattereri, Nyctalus noctula, Pipistrellus nathusii, Pipistrellus pipistrellus, Pipistrellus pygmaeus, Vespertilio murinus), of which breeding of two (M. nattereri, P. nathusii) have been confirmed. The total number of records in the study is 11 234, of which 9717 are identified to species. The records are from 940 (25%) 10-km2 squares of Finland’s land area. Of the records, 89% are new (1993–2014). Of the recorded bat species, only Eptesicus nilssonii occurs in each of the 21 biogeographical provinces. A decreasing south–north gradient in species richness and abundance exists which may be related to research efforts that are clearly higher in the south.
  • Hammerl, Jens Andre; Barac, Andrea; Bienert, Anja; Demir, Aslihan; Drueke, Niklas; Jaeckel, Claudia; Matthies, Nina; Jun, Jin Woo; Skurnik, Mikael; Ulrich, Juliane; Hertwig, Stefan (2022)
    Yersinia pseudotuberculosis is an important animal pathogen, particularly for birds, rodents, and monkeys, which is also able to infect humans. Indeed, an increasing number of reports have been published on zoo animals that were killed by this species. One option to treat diseased animals is the application of strictly lytic (virulent) phages. However, thus far relatively few phages infecting Y. pseudotuberculosis have been isolated and characterized. To determine the prevalence of Y. pseudotuberculosis phages in zoo animals, fecal samples of birds and some primates, maras, and peccaries kept in the Tierpark Berlin were analyzed. Seventeen out of 74 samples taken in 2013 and 2017 contained virulent phages. The isolated phages were analyzed in detail and could be allocated to three groups. The first group is composed of 10 T4-like phages (PYps2T taxon group: Myoviridae; Tevenvirinae; Tequatrovirus), the second group (PYps23T taxon group: Chaseviridae; Carltongylesvirus; Escherichia virus ST32) consists of five phages encoding a podovirus-like RNA polymerase that is related to an uncommon genus of myoviruses (e.g., Escherichia coli phage phiEcoM-GJ1), while the third group is comprised of two podoviruses (PYps50T taxon group: Autographiviridae; Studiervirinae; Berlinvirus) which are closely related to T7. The host range of the isolated phages differed significantly. Between 5.5 and 86.7% of 128 Y. pseudotuberculosis strains belonging to 20 serotypes were lysed by each phage. All phages were additionally able to lyse Y. enterocolitica B4/O:3 strains, when incubated at 37 degrees C. Some phages also infected Y. pestis strains and even strains belonging to other genera of Enterobacteriaceae. A cocktail containing two of these phages would be able to lyse almost 93% of the tested Y. pseudotuberculosis strains. The study indicates that Y. pseudotuberculosis phages exhibiting a broad-host range can be isolated quite easily from zoo animals, particularly birds.
  • Virkkala, Raimo; Lehikoinen, Aleksi (2017)
    Species richness is predicted to increase in the northern latitudes in the warming climate due to ranges of many southern species expanding northwards. We studied changes in the composition of the whole avifauna and in bird species richness in a period of already warming climate in Finland (in northern Europe) covering 1,100km in south-north gradient across the boreal zone (over 300,000km(2)). We compared bird species richness and species-specific changes (for all 235 bird species that occur in Finland) in range size (number of squares occupied) and range shifts (measured as median of area of occupancy) based on bird atlas studies between 1974-1989 and 2006-2010. In addition, we tested how the habitat preference and migration strategy of species explain species-specific variation in the change of the range size. The study was carried out in 10km squares with similar research intensity in both time periods. The species richness did not change significantly between the two time periods. The composition of the bird fauna, however, changed considerably with 37.0% of species showing an increase and 34.9% a decrease in the numbers of occupied squares, that is, about equal number of species gained and lost their range. Altogether 95.7% of all species (225/235) showed changes either in the numbers of occupied squares or they experienced a range shift (or both). The range size of archipelago birds increased and long-distance migrants declined significantly. Range loss observed in long-distance migrants is in line with the observed population declines of long-distance migrants in the whole Europe. The results show that there is an ongoing considerable species turnover due to climate change and due to land use and other direct human influence. High bird species turnover observed in northern Europe may also affect the functional diversity of species communities.
  • Wiedensohler, A.; Andrade, M.; Weinhold, K.; Müller, T.; Birmili, W.; Velarde, F.; Moreno, Adam; Forno, R.; Sanchez, M. F.; Laj, P.; Ginot, P.; Whiteman, D. N.; Krejci, R.; Sellegri, K.; Reichler, T. (2018)
    Urban development, growing industrialization, and increasing demand for mobility have led to elevated levels of air pollution in many large cities in Latin America, where air quality standards and WHO guidelines are frequently exceeded. The conurbation of the metropolitan area of La Paz/El Alto is one of the fastest growing urban settlements in South America with the particularity of being located in a very complex terrain at a high altitude. As many large cities or metropolitan areas, the metropolitan area of La Paz/El Alto and the Altiplano region are facing air quality deterioration. Long-term measurement data of the equivalent black carbon (eBC) mass concentrations and particle number size distributions (PNSD) from the Global Atmosphere Watch Observatory Chacaltaya (CHC; 5240 m a.s.l., above sea level) indicated a systematic transport of particle matter from the metropolitan area of La Paz/El Alto to this high altitude station and subsequently to the lower free troposphere. To better understand the sources and the transport mechanisms, we conducted eBC and PNSDs measurements during an intensive campaign at two locations in the urban area of La Paz/El Alto from September to November 2012. While the airport of El Alto site (4040 m a.s.l.) can be seen as representative of the urban and Altiplano background, the road site located in Central La Paz (3590 m a.s.l.) is representative for heavy traffic-dominated conditions. Peaks of eBC mass concentrations up to 5 mu g m(-3) were observed at the El Alto background site in the early morning and evening, while minimum values were detected in the early afternoon, mainly due to thermal convection and change of the planetary boundary layer height. The traffic-related eBC mass concentrations at the road site reached maximum values of 10-20 mu g m(-3). A complete traffic ban on the specific Bolivian Day of Census (November 21, 2012) led to a decrease of eBC below 1 mu g m(-3) at the road site for the entire day. Compared to the day before and after, particle number concentrations decreased by a factor between 5 and 25 over the particle size range from 10 to 800 nm, while the submicrometer particle mass concentration dropped by approximately 80%. These results indicate that traffic is the dominating source of BC and particulate air pollution in the metropolitan area of La Paz/El Alto. In general, the diurnal cycle of eBC mass concentration at the Chacaltaya observatory is anti-correlated to the observations at the El Alto background site. This pattern indicates that the traffic-related particulate matter, including BC, is transported to higher altitudes with the developing of the boundary layer during daytime. The metropolitan area of La Paz/El Alto seems to be a significant source for BC of the regional lower free troposphere. From there, BC can be transported over long distances and exert impact on climate and composition of remote southern hemisphere.
  • Cai, Runlong; Attoui, Michel; Jiang, Jingkun; Korhonen, Frans; Hao, Jiming; Petäjä, Tuukka; Kangasluoma, Juha (2018)
    Classifying sub-3 nm particles effectively with relatively high penetration efficiencies and sizing resolutions is important for atmospheric new particle formation studies. A high-resolution supercritical differential mobility analyzer (half-mini DMA) was recently improved to classify aerosols at a sheath flow rate less than 100 L/min. In this study, we characterized the transfer functions, the penetration efficiencies, and the sizing resolution of the new half-mini DMA at the aerosol flow rate of 2.5-10 L/min and the sheath flow rate of 25-250 L/min using tetra-alkyl ammonium ions and tungsten oxide particles. The transfer functions of the new half-mini DMA at an aerosol flow rate lower than 5 L/min and a sheath flow rate lower than 150 L/min agree well with predictions using a theoretical diffusing transfer function. The penetration efficiencies can be approximated using an empirical formula. When classifying 1.48 nm molecular ions at an aerosol-to-sheath flow ratio of 5/50 L/min, the penetration efficiency, the sizing resolution, and the multiplicative broadening factor of the new half-mini DMA are 0.18, 6.8, and 1.11, respectively. Compared to other sub-3 nm DMAs applied in atmospheric measurements (e.g. the mini-cyDMA, the TSI DMA 3086, the TSI nanoDMA 3085, and the Grimm S-DMA), the new half-mini DMA characterized in this study is able to classify particles at higher aerosol and sheath flow rates, leading to a higher sizing resolution at the same aerosol-to-sheath flow ratio. Accordingly, the new half-mini DMA can reduce the uncertainties in atmospheric new particle formation measurement if coupled with an aerosol detector that could work at the corresponding high aerosol flow rate. (c) 2018 American Association for Aerosol Research
  • Kangasluoma, Juha; Hering, Susanne; Picard, David; Lewis, Gregory; Enroth, Joonas; Korhonen, Frans; Kulmala, Markku; Sellegri, Karine; Attoui, Michel; Petäjä, Tuukka (2017)
    In this study we characterized the performance of three new particle counters able to detect particles smaller than 3 nm during the Helsinki condensation particle counter (CPC) workshop in summer 2016: the Aerosol Dynamics Inc. (ADI; Berkeley, USA) versatile water condensation particle counter (vWCPC), TSI 3777 nano enhancer (TSI Inc., Shoreview, USA) and modified and boosted TSI 3010-type CPC from Universite Blaise Pascal called a B3010. The performance of all CPCs was first measured with charged tungsten oxide test particles at temperature settings which resulted in supersaturation low enough to not detect any ions produced by a radioactive source. Due to similar measured detection efficiencies, additional comparison between the 3777 and vWCPC were conducted using electrically neutral tungsten oxide test particles and with positively charged tetradodecylammonium bromide. Furthermore, the detection efficiencies of the 3777 and vWCPC were measured with boosted temperature settings yielding supersaturation which was at the onset of homogeneous nucleation for the 3777 or confined within the range of liquid water for the ADI vWCPC. Finally, CPC-specific tests were conducted to probe the response of the 3777 to various inlet flow relative humidities, of the B3010 to various inlet flow rates and of the vWCPC to various particle concentrations. For the 3777 and vWCPC the measured 50% detection diameters (d50s) were in the range of 1.3-2.4 nm for the tungsten oxide particles, depending on the particle charging state and CPC temperature settings, between 2.5 and 3.3 nm for the organic test aerosol, and in the range of 3.2-3.4 nm for tungsten oxide for the B3010.
  • Greiser, Caroline; Hylander, Kristoffer; Meineri, Eric; Luoto, Miska; Ehrlen, Johan (2020)
    The role of climate in determining range margins is often studied using species distribution models (SDMs), which are easily applied but have well-known limitations, e.g. due to their correlative nature and colonization and extinction time lags. Transplant experiments can give more direct information on environmental effects, but often cover small spatial and temporal scales. We simultaneously applied a SDM using high-resolution spatial predictors and an integral projection (demographic) model based on a transplant experiment at 58 sites to examine the effects of microclimate, light and soil conditions on the distribution and performance of a forest herb, Lathyrus vernus, at its cold range margin in central Sweden. In the SDM, occurrences were strongly associated with warmer climates. In contrast, only weak effects of climate were detected in the transplant experiment, whereas effects of soil conditions and light dominated. The higher contribution of climate in the SDM is likely a result from its correlation with soil quality, forest type and potentially historic land use, which were unaccounted for in the model. Predicted habitat suitability and population growth rate, yielded by the two approaches, were not correlated across the transplant sites. We argue that the ranking of site habitat suitability is probably more reliable in the transplant experiment than in the SDM because predictors in the former better describe understory conditions, but that ranking might vary among years, e.g. due to differences in climate. Our results suggest that L. vernus is limited by soil and light rather than directly by climate at its northern range edge, where conifers dominate forests and create suboptimal conditions of soil and canopy-penetrating light. A general implication of our study is that to better understand how climate change influences range dynamics, we should not only strive to improve existing approaches but also to use multiple approaches in concert.
  • Bolotov, Ivan N.; Makhrov, Alexander A.; Gofarov, Mikhail Yu.; Aksenova, Olga V.; Aspholm, Paul E.; Bespalaya, Yulia V.; Kabakov, Mikhail B.; Kolosova, Yulia S.; Kondakov, Alexander V.; Ofenbock, Thomas; Ostrovsky, Andrew N.; Popov, Igor Yu.; von Proschwitz, Ted; Rudzite, Mudite; Rudzitis, Maris; Sokolova, Svetlana E.; Valovirta, Ilmari; Vikhrev, Ilya V.; Vinarski, Maxim V.; Zotin, Alexey A. (2018)
    The effects of climate change on oligotrophic rivers and their communities are almost unknown, albeit these ecosystems are the primary habitat of the critically endangered freshwater pearl mussel and its host fishes, salmonids. The distribution and abundance of pearl mussels have drastically decreased throughout Europe over the last century, particularly within the southern part of the range, but causes of this wide-scale extinction process are unclear. Here we estimate the effects of climate change on pearl mussels based on historical and recent samples from 50 rivers and 6 countries across Europe. We found that the shell convexity may be considered an indicator of the thermal effects on pearl mussel populations under warming climate because it reflects shifts in summer temperatures and is significantly different in viable and declining populations. Spatial and temporal modeling of the relationship between shell convexity and population status show that global climate change could have accelerated the population decline of pearl mussels over the last 100 years through rapidly decreasing suitable distribution areas. Simulation predicts future warming-induced range reduction, particularly in southern regions. These results highlight the importance of large-scale studies of keystone species, which can underscore the hidden effects of climate warming on freshwater ecosystems.
  • Colado, Raquel; Pallarés, Susana; Fresneda, Javier; Mammola, Stefano; Rizzo, Valeria; Sánchez-Fernández, David (2022)
    The climatic variability hypothesis predicts the evolution of species with wide thermal tolerance ranges in environments with variable temperatures, and the evolution of thermal specialists in thermally stable environments. In caves, the extent of spatial and temporal thermal variability experienced by taxa decreases with their degree of specialization to deep subterranean habitats. We use phylogenetic generalized least squares to model the relationship among thermal tolerance (upper lethal limits), subterranean specialization (estimated using ecomorphological traits), and habitat temperature in 16 beetle species of the tribe Leptodirini (Leiodidae). We found a significant, negative relationship between thermal tolerance and the degree of subterranean specialization. Conversely, habitat temperature had only a marginal effect on lethal limits. In agreement with the climatic variability hypothesis and under a climate change context, we show that the specialization process to live in deep subterranean habitats involves a reduction of upper lethal limits, but not an adjustment to habitat temperature. Thermal variability seems to exert a higher evolutionary pressure than mean habitat temperature to configure the thermal niche of subterranean species. Our results provide novel insights on thermal physiology of species with poor dispersal capabilities and on the evolutionary process of adaptation to subterranean environments. We further emphasize that the pathways determining vulnerability of subterranean species to climate change greatly depend on the degree of specialization to deep subterranean environments.
  • Nowik, Katarzyna Ewa; Nowik, Kamil; Kanclerz, Piotr; Szaflik, Jacek Pawel (2022)
    Purpose: Extended depth of focus intraocular (EDOF) IOLs form a bridge between single- and multifocal IOL design. This study aimed to compare clinical outcomes obtained after implanting two different optical designs of EDOF IOLs: the Mini Well Ready (SIFI Medtech, Catania, Italy) and Tecnis Symfony (Abbott Laboratories, Illinois, USA). Methods: The retrospective observational study included 61 patients (122 eyes) who underwent bilateral implantation of the Mini Well Ready IOL (32 patients) or the Tecnis Symfony IOL (29 patients). The following preoperative and postoperative parameters were evaluated: spherical equivalent, anterior astigmatism, pupil size, monocular and binocular uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA), monocular and binocular uncorrected intermediate visual acuity (DIVA) and distance-corrected intermediate visual acuity (DCIVA), monocular and binocular uncorrected near visual acuity (UNVA) and distance-corrected near visual acuity (DCNVA). In the 6 months postoperative period, defocus curve, contrast sensitivity, photopic phenomena, and posterior capsule opacification were assessed. Results: The patients receiving the Tecnis Symfony had slightly better monocular and binocular UDVA and CDVA than with the Mini Well Ready IOL, the differences were not statistically significant. Whereas the DIVA, DCIVA, UNVA, DCNVA, UNVA and DCNVA values were higher in the Mini Well Ready group, the differences were not significant. There were no significant between-group differences regarding the defocus curve for the vast majority of tested vergences. Dysphotopsias postoperatively were assessed at 6 months. Conclusion: Patients receiving both the Mini Well Ready and Symfony IOLs had excellent visual acuity outcomes and spectacle independence.
  • Baibuz, Ekaterina; Vigonski, Simon; Lahtinen, Jyri Kalevi; Zhao, Junlei; Jansson, Ville Bernt Christian; Zadin, Vahur; Djurabekova, Flyura Gatifovna (2018)
    Atomistic rigid lattice Kinetic Monte Carlo (KMC) is an efficient method for simulating nano-objects and surfaces at timescales much longer than those accessible by molecular dynamics. A laborious and non-trivial part of constructing any KMC model is, however, to calculate all migration barriers that are needed to give the probabilities for any atom jump event to occur in the simulations. We have calculated three data sets of migration barriers for Cu self-diffusion with two different methods. The data sets were specifically calculated for rigid lattice KMC simulations of copper self-diffusion on arbitrarily rough surfaces, but can be used for KMC simulations of bulk diffusion as well.
  • Garzon, Marta Benito; Robson, T. Matthew; Hampe, Arndt (2019)
    Improving our understanding of species ranges under rapid climate change requires application of our knowledge of the tolerance and adaptive capacity of populations to changing environmental conditions. Here, we describe an emerging modelling approach, Delta TraitSDM, which attempts to achieve this by explaining species distribution ranges based on phenotypic plasticity and local adaptation of fitness-related traits measured across large geographical gradients. The collection of intraspecific trait data measured in common gardens spanning broad environmental clines has promoted the development of these new models - first in trees but now rapidly expanding to other organisms. We review, explain and harmonize the main findings from this new generation of models that, by including trait variation over geographical scales, are able to provide new insights into future species ranges. Overall, Delta TraitSDM predictions generally deliver a less alarming message than previous models of species distribution under new climates, indicating that phenotypic plasticity should help, to a considerable degree, some plant populations to persist under climate change. The development of Delta TraitSDMs offers a new perspective to analyse intraspecific variation in single and multiple traits, with the rationale that trait (co)variation and consequently fitness can significantly change across geographical gradients and new climates.
  • Liu, Yang; Pellikka, Petri; Li, Hansunbai; Fang, Xiuqi (2019)
    Continuous detection of dispersion and residence of volcanic plumes in troposphere and lower stratosphere is vitally important for improving the understanding on the role of volcano eruptions in climate change. We report a 3-month continuous detection of dispersion and residence of volcanic plumes in the troposphere and stratosphere generated from the volcanic SO2 erupted by Nabro in Eritrea on June 12th, 2011 observed by the OMI sensor. The background SO2 concentration of 3 different height layers in troposphere and lower stratosphere were estimated by the 3-year-average daily concentration of monthly SO2 in 2005, 2007 and 2013, when there were no large explosive volcanic eruptions occurring. We also traced the diffusion path and the concentration of volcanic SO2 for the first 3 months after Nabro's eruption, and detected the appearance and dissipation of sulfate aerosols, which is a product converted from volcanic SO2. The results show that after Nabro erupted on June 12th, the volcanic plumes spread to middle latitudes (30 degrees N -60 degrees N) of Northern Hemisphere and loading by westerly jet. The volcanic SO2 in middle troposphere layer (TRM) and lower troposphere layer (TRL) stopped eastward spreading, and dissipated over the western Pacific Ocean on June 23rd. On June 26th, the volcanic SO2 in upper troposphere and lower stratosphere (STL) reached Mexico in Central America, and almost encircled the low latitudes and parts of middle latitudes. On June 28th, the volcanic SO2 plume showed an even distribution in STL. 37 days after the eruption, the volcanic SO2 in STL encircled the Northern Hemisphere evenly, sulfate aerosols in STL largely covered the low and middle latitudes and the daily concentration of SO2 was still higher than the background value. One month after the eruption, the global mean daily concentration of SO2 dropped to the normal value, but the daily concentration of SO2 and sulfate aerosols in low latitudes remained high, and dissipated not earlier than 3 months after the eruption of Nabro.
  • Korpela, Ilkka; Haapanen, R.; Korrensalo, A.; Tuittila, E-S; Vesala, T. (2020)
    Boreal bogs are important stores and sinks of atmospheric carbon whose surfaces are characterised by vegetation microforms. Efficient methods for monitoring their vegetation are needed because changes in vegetation composition lead to alteration in their function such as carbon gas exchange with the atmosphere. We investigated how airborne image and waveform-recording LiDAR data can be used for 3D mapping of microforms in an open bog which is a mosaic of pools, hummocks with a few stunted pines, hollows, intermediate surfaces and mud-bottom hollows. The proposed method operates on the bog surface, which is reconstructed using LiDAR. The vegetation was classified at 20 cm resolution. We hypothesised that LiDAR data describe surface topography, moisture and the presence and depth of field-layer vegetation and surface roughness; while multiple images capture the colours and texture of the vegetation, which are influenced by directional reflectance effects. We conclude that geometric LiDAR features are efficient predictors of microforms. LiDAR intensity and echo width were specific to moisture and surface roughness, respectively. Directional reflectance constituted 4-34 % of the variance in images and its form was linked to the presence of the field layer. Microform-specific directional reflectance patterns were deemed to be of marginal value in enhancing the classification, and RGB image features were inferior to LiDAR variables. Sensor fusion is an attractive option for fine-scale mapping of these habitats. We discuss the task and propose options for improving the methodology.
  • Blomberg, Anna S.; Vasko, Ville; Salonen, Saku; Petersons, Gunars; Lilley, Thomas M. (2021)
    Highly mobile species are considered to be the first to respond to climate change by transforming their ranges of distribution. There is evidence suggesting that Pipistrellus nathusii, a species capable of long-distance migration, is expanding both its reproduction and overwintering ranges to the North. We recorded the echolocation calls of bats at 16 sites in South-Western Finland on two consecutive winters, and detected calls of P. nathusii at one of the sites throughout the second winter. To our knowledge, this is the northernmost record of an overwintering P. nathusii, and contributes to evidence that the species is already responding to climate change.
  • Kangasluoma, Juha; Ahonen, Lauri R.; Laurila, Tiia M.; Cai, Runlong; Enroth, Joonas; Mazon, Stephany Buenrostro; Korhonen, Frans; Aalto, Pasi P.; Kulmala, Markku; Attoui, Michel; Petäjä, Tuukka (2018)
    Measurement of atmospheric sub-10 nm nanoparticle number concentrations has been of substantial interest recently, which, however, is subject to considerable uncertainty. We report a laboratory characterization of a high flow differential mobility particle sizer (HFDMPS), which is based on the Half-mini type differential mobility analyzer (DMA) and nano condensation nuclei counter (A11), and show the first results from atmospheric observations. The HFDMPS utilizes the state-of-the-art aerosol technology, and is optimized for sub-10 nm particle size distribution measurements by a moderate resolution DMA, optimized and characterized low-loss particle sampling line and minimal dilution in the detector. We present an exhaustive laboratory calibration to the HFDMPS and compare the measured size data to the Hyytiala long-term DMPS and Neutral cluster and ion spectrometer. The HFDMPS detects about two times higher 3-10 nm particle concentrations than the long-term DMPS, and the counting uncertainties are halved as compared to the long-term DMPS. The HFDMPS did not observe any sub-2.5 nm particles in Hyytiala, and the reason for that was shown to be the inability of diethylene glycol to condense on such small biogenic particles. Last, we discuss the general implications of our results to the sub-10 nm DMPS based measurements.
  • Nordlund, Kai; Hori, Masaki; Sundholm, Dage (2022)
    We simulate the deceleration and transmission of antiprotons with keV-scale kinetic energies through polymer foils using a molecular dynamics approach, which includes a model of nuclear stopping based on the attractive interaction potentials between antiprotons and target atoms calculated by quantum chemical methods. Antiprotons scatter into larger angles with higher cross sections than protons. This causes a significant fraction of antiprotons to annihilate in the foil instead of emerging with energies of a few keV, especially when coatings of materials with high atomic number are applied to the surfaces. The simulation results are in good agreement with data from two experiments that involved pulsed antiproton beams with incident energies between 63 keV and 122 keV that traverse polymer foils with thicknesses of approximate to 1.3 mu m and 1.8 mu m. The 25-nm-thick layers of Ag on the latter foil reduced the transmission of antiprotons. The results will be utilized to design the degrader foils in laser spectroscopy experiments of antiprotonic helium atoms and experiments involving Penning traps that are carried out at the ELENA facility of CERN.