Numerical modelling of the backscattering of dual-polarization weather radar

Polarimetriset säätutkat ovat tulossa lähiaikoina operatiiviseen käyttöön Suomessa ja muualla maailmassa. Polarimetriset säätutkat tuovat lisää informaatiota ilmakehän hydrometeorien mittaukseen ja mahdollistavat siten perinteisiä säätutkia tarkemman sateen vesimäärän arvioinnin ja sateen olomuotojen luokittelun. Polarimetristen säätutkien parempaa hyödyntämistä varten tarvitaan lisää tietoa erilaisten hydrometeorien sirontaominaisuuksista . Tässä työssä tehtiin modifioitua DDA- eli diskreettidipoliapproksimaatiolaskentaa ja nollannen asteen säteilynkuljetusteoriaa käyttävä sirontamallinnusohjelma. Ohjelma kykenee laskemaan yksittäisen partikkelin eteenpäin ja takaisinsirontaparametrit eri polarisaatioille ja samoista kappaleista käyttäjän antamalla tiheydellä muodostuvan kerroksen sironta- ja vaimennusominaisuudet. Ohjelman toiminta validoitiin vertaamalla pallomaisten kappaleiden mallinnustuloksia analyyttisiin, ja siten tarkasti oikean tuloksen antaviin Mie-sirontatuloksiin. Ohjelmaa käytettiin sulavan lumi-, räntä- ja vesisateen etenemisvaimennuksen mallintamiseen. Ohjelmalla tutkittiin miten etenemisvaimennus muuttuu partikkelin sisältämän vesimäärän kasvaessa ja kuinka veden sijoittuminen eri puolille kappaletta vaikuttaa eri polarisaatioilla tapahtuvaan vaimennukseen. Sulamista mallinnettiin yksinkertaisella mallilla, jossa on neljä sulamisvaihetta. Vaimennusmallinnuksen tuloksista havaittiin, miten HH- ja VV-polarisaatioiden ero kasvaa voimakkaasti, kun partikkelin alaosaan kertyy nestemäistä vettä tai kun partikkelin muoto muuttuu litteämmäksi. Pallosymmetristä tilannetta kuvaavassa toisen sulamisvaiheen partikkelissa havaittiin oletuksen vastaisesti myös jonkin verran eroa polarisaatioiden vaimennustuloksissa. Ongelman oletettiin johtuvan tavasta, jolla partikkelit luotiin, eikä varsinaisesta mallinnusohjelmasta, joka vaikuttaa muuten toimivan oletetusti.Polarimetric weather radars will be in operational use in the near future. Polarimetric weather radars provide more information in the measurement of the atmospheric hydrometeors when compared to traditional weather radars. Hence more accurate estimates of the rain water content and precipitation types can be attained. In order to make better use of the features of polarimetric weather radars more information on the scattering properties of hydrometeors is needed. In this thesis a program, that models scattering using modified DDA calculation and the zeroeth degree radiative transfer theory, was made. The program is able to calculate forward and backscattering parameters of a single particle and scattering and attenuation properties for a layer consisting of those particles with a specified numerical density. The results from program for spherical particles were validated by comparing them to Mie scattering results, which are analytical, and therefore, true results for the scattering situation. The program was used to model attenuation due to hydrometeors in the melting layer. It was studied how the propagation attenuation changes when the water volume fraction in the particles increases and how differential accumulation of the water affects the attenuation in different polarization components. Melting of the particle was modeled with a simple model with four phases of melting. The results of the attenuation modeling suggest, that the difference between HH and VV polarizations increases strongly when more water accumulates in the bottom of the particle and when the particle changes to a flatter shape. The second phase of the melting was spherically symmetric but contrary, to the initial assumption, differences between attenuation results for different polarizations were noticed. The problem was assumed to be caused by the way the particles were generated and not by the program which otherwise seems to be working properly

Female C57BL/6J Mice Show Alcohol-Seeking Behaviour after Withdrawal from Prolonged Alcohol Consumption in the Social Environment.

Aims Recently we developed a model to study alcohol-seeking behaviour after withdrawal in a social context in female mice. The model raised several questions that we were eager to address to improve methodology. Methods In our model, female mice were group-housed in automated cages with three conditioned (CS+) corners and water in both sides of one separate non-conditioned corner. Water was available with opened doors at all the time of training. We established conditioning by pairing alcohol drinking with light cues. Here, we introduced prolonged access to increasing concentrations of alcohol instead of intermittent access. To study motivation to drink alcohol, we carried out the extinction tests on withdrawal days 1 (WD1) and 10 (WD10). During tests, the light cues were present in conditioned corners, but there was no liquid in the bottles. Results We found that the number of visits and nosepokes in the CS+ corner in the alcohol group was much higher than in the water group. Also, during training, the consumption of alcohol was increasing. In the extinction tests, we found that the number of nosepokes in the CS+ corner increased in the alcohol group on both WD1 and WD10. Conclusions Our study supports that alcohol-seeking behaviour after withdrawal can be modelled and studied in group-housed animals and environments without social isolation. Short Summary: We developed a model to study alcohol drinking behaviour in an enriched and social environment. Long-term conditioning coupling with alcohol reward results in cue-induced alcohol-seeking behaviour in group-housed female C57BL/6J mice. Moreover, a high number of nosepokes on the last day of alcohol drinking conditioning might potentiate alcohol-seeking after withdrawal response.Peer reviewe

Dopaminergic modulation of reward-guided decision making in alcohol-preferring AA rats

R**esults from animal gambling models have highlighted the importance of dopaminergic neurotransmission in modulating decision making when large sucrose rewards are combined with uncertainty. The majority of these models use food restriction as a tool to motivate animals to accomplish operant behavioral tasks, in which sucrose is used as a reward. As enhanced motivation to obtain sucrose due to hunger may impact its reward-seeking effect, we wanted to examine the decision-making behavior of rats in a situation where rats were fed ad libitum. For this purpose, we chose alcohol-preferring AA (alko alcohol) rats, as these rats have been shown to have high preference for sweet agents. In the present study, AA rats were trained to self-administer sucrose pellet rewards in a two-lever choice task (one pellet vs. three pellets). Once rational choice behavior had been established, the probability of gaining three pellets was decreased over time (50%, 33%, 25% then 20%). The effect of D-amphetamine on decision making was studied at every probability level, as well as the effect of the dopamine D-1 receptor agonist SKF-81297 and D-2 agonist quinpirole at probability levels of 100% and 25%. D-Amphetamine increased unprofitable choices in a dose-dependent manner at the two lowest probability levels. Quinpirole increased the frequency of unprofitable decisions at the 25% probability level, and SKF-82197 did not affect choice behavior. These results mirror the findings of probabilistic discounting studies using food-restricted rats. Based on this, the use of AA rats provides a new approach for studies on reward-guided decision making. (C) 2017 Elsevier B.V. All rights reserved.Peer reviewe

High road mortality during female-biased larval dispersal in an iconic beetle

Animals often disperse from one habitat to another to access mates or suitable breeding sites. The costs and benefits of such movements depend, in part, on the dispersing individuals' phenotypes, including their sex and age. Here we investigated dispersal and road-related mortality in larvae of a bioluminescent beetle, the European common glow-worm, Lampyris noctiluca, in relation to habitat, sex and proximity of pupation. We expected these variables to be relevant to larval dispersal because adult females are wingless, whereas adult males fly when searching for glowing females. We found that dispersing glow-worm larvae were almost exclusively females and close to pupation. The larvae were often found on a road, where they were able to move at relatively high speeds, with a tendency to uphill orientation. However, each passing vehicle caused a high mortality risk, and we found large numbers of larvae run over by cars, especially close to covered, forest-like habitat patches. In contrast, adult females in the same area were most often found glowing in more open rocky and grassy habitats. These findings demonstrate an underappreciated ecological strategy, sex-biased dispersal at larval phase, motivated by different habitat needs of larvae and wingless adult females. The results are also consistent with roads being an ecological trap, facilitating dispersal and presumably females' signal visibility but causing severe larval mortality just before the reproductive stage. Hence, in addition to the previously recognised threats of urbanisation, even low traffic volumes have a high potential to negatively affect especially females of this iconic beetle. Significance statement Animals sometimes need to move from one habitat to another to find mating partners or breeding sites. We found this need to result in strongly female-biased larval dispersal in the European common glow-worm, a beetle known for the glow of wingless females that attract flying males to mate. Female larvae moving between habitats often used a road or trail but perished in high numbers when run over by cars. Hence, roads are likely to be ecological traps for the female glow-worm larvae, attracting them during dispersal, but causing grave mortality. The sex-biased larval dispersal, demonstrated in this study, is a poorly known ecological strategy that was found to be very risky in a human-modified landscape.Peer reviewe

Prolyl Oligopeptidase Regulates Dopamine Transporter Phosphorylation in the Nigrostriatal Pathway of Mouse

Alpha-synuclein is the main component of Lewy bodies, a histopathological finding of Parkinson's disease. Prolyl oligopeptidase (PREP) is a serine protease that binds to alpha-synuclein and accelerates its aggregation in vitro. PREP enzyme inhibitors have been shown to block the alpha-synuclein aggregation process in vitro and in cellular models, and also to enhance the clearance of alpha-synuclein aggregates in transgenic mouse models. Moreover, PREP inhibitors have induced alterations in dopamine and metabolite levels, and dopamine transporter immunoreactivity in the nigrostriatal tissue. In this study, we characterized the role of PREP in the nigrostriatal dopaminergic and GABAergic systems of wild-type C57Bl/6 and PREP knockout mice, and the effects of PREP overexpression on these systems. Extracellular concentrations of dopamine and protein levels of phosphorylated dopamine transporter were increased and dopamine reuptake was decreased in the striatum of PREP knockout mice, suggesting increased internalization of dopamine transporter from the presynaptic membrane. Furthermore, PREP overexpression increased the level of dopamine transporters in the nigrostriatal tissue but decreased phosphorylated dopamine transporters in the striatum in wild-type mice. Our results suggest that PREP regulates the function of dopamine transporter, possibly by controlling the phosphorylation and transport of dopamine transporter into the striatum or synaptic membrane.Peer reviewe

Constitutive Ret signaling leads to long-lasting expression of amphetamine-induced place conditioning via elevation of mesolimbic dopamine

Addictive drugs enhance dopamine release in the striatum, which can lead to compulsive drug-seeking after repeated exposure. Glial cell line-derived neurotrophic factor (GDNF) is an important regulator of midbrain dopamine neurons, and may play a mechanistic role in addiction-related behaviors. To elucidate the components of GDNF-signaling that contribute to addiction-related behaviors of place preference and its extinction, we utilized two genetically modified GDNF mouse models in an amphetamine induced conditioned place preference (CPP) paradigm and evaluated how the behavioral findings correlate with dopamine signaling in the dorsal and ventral striatum. We utilized two knock-in mouse strains to delineate contributions of GDNF and Ret signaling using MEN2B mice (constitutively active GDNF receptor Ret), and GDNF hypermorphic mice (enhanced endogenous GDNF expression). The duration of amphetamine-induced CPP was greatly enhanced in MEN2B mice, but not in the GDNF hypermorphic mice. The enhanced duration of CPP was correlated with increased tyrosine hydroxylase (TH) expression and dopamine content in the ventral striatum. Together, our results suggest that downstream components of GDNF signaling, in this case Ret, may mediate persistent drug-seeking behavior through increased TH expression and dopamine levels in the mesolimbic dopamine neurons. (C) 2017 Elsevier Ltd. All rights reserved.Peer reviewe

Dicer and microRNAs protect adult dopamine neurons

MicroRNAs (miRs) are important post-transcriptional regulators of gene expression implicated in neuronal development, differentiation, aging and neurodegenerative diseases, including Parkinson's disease (PD). Several miRs have been linked to PD-associated genes, apoptosis and stress response pathways, suggesting that deregulation of miRs may contribute to the development of the neurodegenerative phenotype. Here, we investigate the cell-autonomous role of miR processing RNAse Dicer in the functional maintenance of adult dopamine (DA) neurons. We demonstrate a reduction of Dicer in the ventral midbrain and altered miR expression profiles in laser-microdissected DA neurons of aged mice. Using a mouse line expressing tamoxifen-inducible CreERT2 recombinase under control of the DA transporter promoter, we show that a tissue-specific conditional ablation of Dicer in DA neurons of adult mice led to decreased levels of striatal DA and its metabolites without a reduction in neuronal body numbers in hemizygous mice (Dicer(HET)) and to progressive loss of DA neurons with severe locomotor deficits in nullizygous mice (Dicer(CKO)). Moreover, we show that pharmacological stimulation of miR biosynthesis promoted survival of cultured DA neurons and reduced their vulnerability to thapsigargin-induced endoplasmic reticulum stress. Our data demonstrate that Dicer is crucial for maintenance of adult DA neurons, whereas a stimulation of miR production can promote neuronal survival, which may have direct implications for PD treatment.Peer reviewe

Characterization of the Structural and Functional Determinants of MANF/CDNF in Drosophila In Vivo Model

Peer reviewe

Mice Deficient in Transmembrane Prostatic Acid Phosphatase Display Increased GABAergic Transmission and Neurological Alterations

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Meriseurannan tiekartta – SYKEn ylläpitämien ja koordinoimien meren tilaseurantojen nykytila ja kehittäminen

Raportissa kuvataan nykyiset SYKEn ylläpitämät ja koordinoimat meren kuormitus- ja tilaseurannat ja esitetään tavoitteita seurantojen kehittämiselle ja seurantatiedon käytön tehostamiselle vuoteen 2026 mennessä. Työ perustuu vuonna 2016 tehtyyn meriseurantojen toteutusta ja niiden kehittämistarvetta koskeneeseen kyselyyn, joka lähetettiin n. 30 seurantojen ja kehittämishankkeiden vastuuhenkilölle SYKEssä. Vastausten perusteella koottiin tiekartan alustava luonnos, jota on vuosina 2018-2019 päivitetty ja tarkistettu yhteistyössä seurantojen ja kehittämishankkeiden vastuuhenkilöiden kanssa. Nyt raportoitava versio antaa ajantasaisen kuvan SYKEn ylläpitämistä ja koordinoimista meren tilaseurannoista ja niiden kehittämisestä heinäkuussa 2020 alkaneen merenhoidon toisen seurantakauden kynnyksellä. Työ jakautuu aihealueisiin, joita ovat manuaaliseen näytteenottoon perustuva seuranta, automaatio, kaukokartoitus, kansalaishavainnointi, seurannan tietojärjestelmät, mallinnus ja sen tietotarpeet, seurantojen optimointi ja aineistojen yhteiskäyttö sekä merenhoidon ja HELCOM -työn tietotarpeet. Lisäksi tarkastellaan seuranta-aineistojen käyttöä. Seurantojen kehittämiselle esitetään välittömät tavoitteet (vastikään valmistunut tai valmistumassa oleva kehittämistyö) sekä tavoitteet vuoden 2020 aikana ja vuoteen 2026 mennessä