In situ cloud ground-based measurements in the Finnish sub-Arctic : intercomparison of three cloud spectrometer setups

Continuous, semi-long-term, ground-based in situ cloud measurements were conducted during the Pallas Cloud Experiment (PaCE) in 2013. The measurements were carried out in Finnish sub-Arctic region at Sammaltunturi station (67 degrees 58 ' N, 24 degrees 07 ' E; 560m a.s.l.), part of Pallas Atmosphere - Ecosystem Supersite and Global Atmosphere Watch (GAW) program. The main motivation of the campaign was to conduct in situ cloud measurements with three different cloud spectrometer probes and perform an evaluation of their ground-based setups. Therefore, we mutually compared the performance of the cloud and aerosol spectrometer (CAS), the cloud droplet probe (CDP) and the forward-scattering spectrometer probe (FSSP-100) (DMT; Boulder, CO, USA). We investigated how different meteorological parameters affect each instrument's ground-based setup operation and quantified possible biases and discrepancies of different microphysical cloud properties. Based on the obtained results we suggested limitations for further use of the instrument setups in campaigns where the focus is on investigating aerosol-cloud interactions. Measurements in this study were made by instruments owned by the Finnish Meteorological Institute and results concern their operation in sub-Arctic conditions with frequently occurring supercooled clouds. The measured parameter from each instrument was the size distribution, and additionally we derived the number concentration, the effective diameter, the median volume diameter and the liquid water content. A complete intercomparison between the CAS probe and the FSSP-100 ground setups and additionally between the FSSP-100 and the CDP probe ground setups was made and presented. Unfortunately, there was not a sufficient amount of common data to compare all three probes together due to operational problems of the CDP ground setup in sub-zero conditions. The CAS probe that was fixed to one direction lost a significant number of cloud droplets when the wind direction was out of wind iso-axial conditions in comparison with the FSSP-100 and the CDP, which were both placed on a rotating platform. We revealed that CAS and FSSP-100 had good agreement in deriving sizing parameters (effective diameter and median volume diameter from 5 to 35 mu m) even though CAS was losing a significant amount of cloud droplets. The most sensitive derived parameter was liquid water content, which was strongly connected to the wind direction and temperature.Peer reviewe

Fishing-induced versus natural selection in different brown trout (Salmo trutta) strains

Wild, adfluvial brown trout (Salmo trutta) are iconic targets in recreational fisheries but also endangered in many native locations. We compared how fishing and natural selection affect the fitness-proxies of brown trout from two pure angling-selected strains and experimental crosses between an adfluvial, hatchery-bred strain and three wild, resident strains. We exposed age 1+ parr to predation risk under controlled conditions where their behaviour was monitored with PIT-telemetry, and stocked age 2+ fish in two natural lakes for experimental fishing. Predation mortality (16% of the fish) was negatively size-dependent, while capture probability, also reflecting survival, in the lakes (38.9% of the fish) was positively length- and condition- dependent. Angling-induced selection against low boldness and slow growth rates relative to gillnet fishing indicated gear-dependent potential for fisheries-induced evolution in behaviours and life-histories. Offspring of wild, resident fish showed slower growth rates than the crossbred strains. Strain effects suggested significant heritable scope for artificial selection on life-history traits and demonstrated that choices of fish supplementation by stocking may override the genetic effects induced by angling.Peer reviewe

Does enriched rearing during early life affect sperm quality or skin colouration in the adult brown trout?

Enriched rearing has been demonstrated to shape the phenotype of hatchery-reared salmonids and improve their post-release survival in the wild, thus having an important applied value in conservation. However, it is unclear if rearing conditions or survival selection during the early life stages induce long-term fitness effects on adult phenotypes. Using a paired full-sib set-up, we investigated the influence of the environmental enrichment at the egg and fry stages on the milt quality and skin colouration of the adult brown trout (Salmo trutta L.). Overall, males had a higher number of skin spots than females. Notably, the total numbers of spots and black spots were significantly lower in fish raised in an enriched environment than in their full siblings reared in a conventional hatchery environment. However, neither sperm motility nor sperm swimming behaviour differed between full sib males reared in different environments. Our results suggest that rearing method may shape the colouration of brown trout, either by ecological carry-over effects or by selective survival during the rearing process. This, in turn, indicates that ecological conditions at early life can have long-prevailing phenotypically plastic or microevolutionary effects on the adult traits of fish. These effects should be taken into consideration to better understand the ecological role of rearing methodology in salmonid conservation.Peer reviewe

Comparing RADseq and microsatellites for estimating genetic diversity and relatedness - Implications for brown trout conservation

The conservation and management of endangered species requires information on their genetic diversity, relatedness and population structure. The main genetic markers applied for these questions are microsatellites and single nucleotide polymorphisms (SNPs), the latter of which remain the more resource demanding approach in most cases. Here, we compare the performance of two approaches, SNPs obtained by restriction-site-associated DNA sequencing (RADseq) and 16 DNA microsatellite loci, for estimating genetic diversity, relatedness and genetic differentiation of three, small, geographically close wild brown trout (Salmo trutta) populations and a regionally used hatchery strain. The genetic differentiation, quantified as F-ST, was similar when measured using 16 microsatellites and 4,876 SNPs. Based on both marker types, each brown trout population represented a distinct gene pool with a low level of interbreeding. Analysis of SNPs identified half- and full-siblings with a higher probability than the analysis based on microsatellites, and SNPs outperformed microsatellites in estimating individual-level multilocus heterozygosity. Overall, the results indicated that moderately polymorphic microsatellites and SNPs from RADseq agreed on estimates of population genetic structure in moderately diverged, small populations, but RADseq outperformed microsatellites for applications that required individual-level genotype information, such as quantifying relatedness and individual-level heterozygosity. The results can be applied to other small populations with low or moderate levels of genetic diversity.Peer reviewe

New particle formation, growth and apparent shrinkage at a rural background site in western Saudi Arabia

Atmospheric aerosols have significant effects on human health and the climate. A large fraction of these aerosols originates from secondary new particle formation (NPF), where atmospheric vapors form small particles that subsequently grow into larger sizes. In this study, we characterize NPF events observed at a rural background site of Hada Al Sham (21.802 degrees N, 39.729 degrees E), located in western Saudi Arabia, during the years 2013-2015. Our analysis shows that NPF events occur very frequently at the site, as 73 % of all the 454 classified days were NPF days. The high NPF frequency is likely explained by the typically prevailing conditions of clear skies and high solar radiation, in combination with sufficient amounts of precursor vapors for particle formation and growth. Several factors suggest that in Hada Al Sham these precursor vapors are related to the transport of anthropogenic emissions from the coastal urban and industrial areas. The median particle formation and growth rates for the NPF days were 8.7 cm(-3) s(-1) (J(7)(nm)) and 7.4 nm h(-1) (GR(7-12nm)), respectively, both showing highest values during late summer. Interestingly, the formation and growth rates increase as a function of the condensation sink, likely reflecting the common anthropogenic sources of NPF precursor vapors and primary particles affecting the condensation sink. A total of 76 % of the NPF days showed an unusual progression, where the observed diameter of the newly formed particle mode started to decrease after the growth phase. In comparison to most long-term measurements, the NPF events in Hada Al Sham are exceptionally frequent and strong both in terms of formation and growth rates. In addition, the frequency of the decreasing mode diameter events is higher than anywhere else in the world.Peer reviewe

Latent class analysis reveals clinically relevant atopy phenotypes in 2 birth cohorts

Background: Phenotypes of childhood-onset asthma are characterized by distinct trajectories and functional features. For atopy, definition of phenotypes during childhood is less clear. Objective: We sought to define phenotypes of atopic sensitization over the first 6 years of life using a latent class analysis (LCA) integrating 3 dimensions of atopy: allergen specificity, time course, and levels of specific IgE (sIgE). Methods: Phenotypes were defined by means of LCA in 680 children of the Multizentrische Allergiestudie (MAS) and 766 children of the Protection against allergy: Study in Rural Environments (PASTURE) birth cohorts and compared with classical nondisjunctive definitions of seasonal, perennial, and food sensitization with respect to atopic diseases and lung function. Cytokine levels were measured in the PASTURE cohort. Results: The LCA classified predominantly by type and multiplicity of sensitization (food vs inhalant), allergen combinations, and sIgE levels. Latent classes were related to atopic disease manifestations with higher sensitivity and specificity than the classical definitions. LCA detected consistently in both cohorts a distinct group of children with severe atopy characterized by high seasonal sIgE levels and a strong propensity for asthma; hay fever; eczema; and impaired lung function, also in children without an established asthma diagnosis. Severe atopy was associated with an increased IL-5/IFN-gamma ratio. A path analysis among sensitized children revealed that among all features of severe atopy, only excessive sIgE production early in life affected asthma risk. Conclusions: LCA revealed a set of benign, symptomatic, and severe atopy phenotypes. The severe phenotype emerged as a latent condition with signs of a dysbalanced immune response. It determined high asthma risk through excessive sIgE production and directly affected impaired lung function.Peer reviewe

Homogenous nucleation rates of n-propanol measured in the Laminar Flow Diffusion Chamber at different total pressures

Nucleation rates of n-propanol were investigated in the Laminar Flow Diffusion Chamber. Nucleation temperatures between 270 and 300 K and rates between 100 and 106 cm(-3) s(-1) were achieved. Since earlier measurements of n-butanol and n-pentanol suggest a dependence of nucleation rates on carrier gas pressure, similar conditions were adjusted for these measurements. The obtained data fit well to results available from literature. A small positive pressure effect was found which strengthen the assumption that this effect is attributed to the carbon chain length of the n-alcohol [D. Brus, A. P. Hyv rinen, J. Wedekind, Y. Viisanen, M. Kulmala, V. Zd mal, J. Smolik, and H. Lihavainen, J. Chem. Phys. 128, 134312 (2008)] and might be less intensive for substances in the homologous series with higher equilibrium vapor pressure. A comparison with the theoretical approach by Wedekind et al. [Phys. Rev. Lett. 101, 12 (2008)] shows that the effect goes in the same direction but that the intensity is much stronger in experiments than in theory. (C) 2014 AIP Publishing LLC

Measurements to Study the Coexistence of Private LTE TDD Networks in 2.3 GHz Band

Private wireless networks have recently gained interest in many business applications. Use of 4G and 5G technologies for private network deployments has become feasible recently. Finnish Transport and Communications Agency Traficom began to grant licenses for private mobile Time Division Duplex (TDD) networks on frequency band 2300-2320 MHz in 2020. In this study, the coexistence of two 4G TDD networks is investigated through an extensive measurement campaign. The laboratory test setup developed to conduct the interference measurement campaign can be used to study 4G and 5G TDD technologies in frequency bands below 4 GHz. Networks using TDD technology are recommended to use synchronized frame configurations to avoid interference. Private network applications and requirements differ between user organisations and hence the uplink and downlink data rate requirements are different and may need different TDD frame configurations. This paper studies interference between adjacent private networks, which have same or different TDD frame configurations. Measurement results indicate that non-synchronized networks produce interference and significant decrease in data throughput in neighboring networks

Field Measurements to Study the Co-Existence of Geographically Limited Local Industrial Mobile TDD Networks

Use of 4G and 5G technologies for local industrial networks has become feasible in recent years. This paper studies the co-existence of two geographically limited adjacent Time Division Duplex (TDD) local networks through a field measurement campaign. The networks have the same or different TDD frame configurations. The test setup developed to conduct the interference measurement campaign can be used to study both 4G and 5G TDD technologies. Measurement results indicate that non-synchronized networks produce interference and significant decrease in data throughput in neighboring networks. Thus, networks using TDD technology are recommended to use synchronized frame configurations to avoid interference. However, local network applications and their requirements may differ between user organizations, and hence the uplink and downlink data rate requirements are different and may need different TDD frame configurations