Land–ice interaction in the Baltic Sea

An overview of the evolution of landfast ice in the Baltic Sea, especially in the vicinity of Hailuoto Island in the north, is given, and semi-analytical models are presented to examine the vertical and lateral growth and breakage of landfast ice. The outer edge of landfast ice moves further offshore as the ice becomes thicker. Occasionally, landfast ice breaks and moves, forming grounded ridges, scouring the sea bottom, piling up on the shore and riding up onto land up to distances of more than 100 m. According to observations of ice breakage, the yield strength of landfast ice is proportional to the squared ice thickness. In very shallow areas the water may freeze to the bottom, and after sea level rise the ice may drift away and transport bottom sediment. The models provide a first-order approach to understand the evolution of the landfast ice zone from the start to the winter maximum

Studies on TGF-β family signalling in the diseased lung tissue

This thesis focuses on transforming growth factor (TGF)-β signalling system in the human lung. Two lung parenchymal diseases, idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD), were studied. In IPF, persistent fibroblasts and extracellular matrix accumulate in the lung parenchyma, causing thickening of the parenchyma with subsequent difficulties in breathing. An opposing process in the lung parenchyma is seen in emphysematous lung in COPD, where alveolar wall damage causes loss of alveolar structure and shortness of breath. The aim of the study was to examine alterations in TGF-β signalling activity in pathologically distinct areas of damaged lung tissue (fibrosis, emphysema). Furthermore, TGF-β signalling properties, i.e. storage and activation, as well as the role of transcription factor GATA-6 in the pathogenesis of IPF were studied. Finally, novel treatment options for IPF were sought. The studied materials were tissue samples from patient lung biopsies along with a selection of commercial and primary lung cell lines. Gene expression levels and protein (co)localization as well as cell differentiation were studied with modern molecular biology tools. Reporter cells and high-throughput screening were used in the search for new candidate drugs for IPF. The results of the screen were validated in a mouse model of silica-induced pulmonary fibrosis. The results showed that TGF-β signalling activity varies within pathologically distinct areas of the lung, with emphysematous areas showing decreased and fibrotic areas showing increased signalling activity. In fibrotic tissue, this is accompanied by a significant increase in the storage and activation of latent TGF-β. It is a common belief that the fibroblastic foci (i.e. aggregates of (myo)fibroblasts) in IPF consist of actively proliferating cells. Here, this view was challenged as fibroblastic foci were found to consist of quiescent, non-proliferating and non-apoptotic cells. These cells, however, were still responsive to TGF-β signals, suggesting that they keep contributing to the extracellular matrix accumulation. Transcription factor GATA-6 was found to be a crucial mediator of the TGF-β-induced cell differentiation of epithelial cells and fibroblasts towards a myofibroblast-like phenotype. For the first time in IPF research, high-throughput screening technology was used in the search for novel treatment options. The results were promising: primary in vitro data revealed one compound which affected TGF-β family signalling and showed biologically significant antifibrotic effects in a mouse model of fibrosis. The data obtained here offers a starting point for further studies.Idiopaattisessa keuhkofibroosissa (idiopathic pulmonary fibrosis, IPF) soluja ja soluväliainetta alkaa tuntemattomasta syystä kertyä keuhkokudokseen. Tämän seurauksena keuhkokudos paksuuntuu ja kaasujenvaihto vaikeutuu. Vastakkainen ilmiö on keuhkoahtaumataudille (chronic obstructive pulmonry disease, COPD) tyypillinen emfyseema eli keuhkojen laajentuma, jossa keuhkorakkularakenne on tuhoutunut. Tämän tutkimuksen tavoitteena oli selvittää TGF-β-sytokiinin (transforming growth factor-beta) signaalinvälityksessä tapahtuvia muutoksia vaurioituneiden keuhkojen eri alueilla (fibroosi, emfyseema). Lisäksi tutkittiin TGF-β:n varastointia ja aktivaatiota sekä transkriptiofaktori GATA-6:n roolia keuhkofibroosin patogeneesissä. Lopuksi etsittiin uusia mahdollisuuksia keuhkofibroosin lääkehoitoon. Tutkimusmateriaaleina käytettiin keuhkokudosnäytteitä sekä erilaisia solulinjoja. Geenien ilmentymistä, proteiinien sijaintia kudoksessa sekä solujen erilaistumista tutkittiin modernein ja monipuolisin molekyylibiologian menetelmin. Molekyylikirjastojen seulonnassa hyödynnettiin tehoseulontateknologiaa. Tutkimustulokset osoittivat, että TGF-β-signalointiaktiivisuus vaihtelee vaurioituneen keuhkokudoksen eri alueilla: se oli laskenut keuhkokudosnäytteiden emfysemaattisilla alueilla ja kohonnut fibroottisilla alueilla. Fibroottisessa keuhkokudoksessa havaittiin merkittävää nousua myös TGF-β:n varastointiin ja aktivaatioon liittyvän proteiinin ilmentymisessä. Perinteisesti on uskottu, että fibroblastifokukset eli fibroosille tyypilliset (myo)fibroblastisolujen muodostamat pesäkkeet muodostuvat aktiivisesti jakautuvista soluista. Tutkimustulostemme mukaan näiden pesäkkeiden solut näyttäisivät kuitenkin olevan lepotilassa, ts. niillä ei havaittu aktiivista solunjakautumista tai ohjelmoitua solukuolemaa. Tästä huolimatta myofibroblastit olivat säilyttäneet kykynsä ottaa vastaan TGF-β-välitteisiä signaaleja, mikä viittaisi siihen, että ne edelleen ylläpitävät soluväliaineen tuottoa. Transkriptiofaktori GATA-6:n todettiin olevan oleellinen osa TGF-β:n indusoimaa, epiteeli- ja fibroblastisolujen erilaistumista ohjaavaa signaalinvälitysreittiä. Tehoseulontateknologiaa käytettiin ensimmäistä kertaa IPF-tutkimuksessa. Tulokset olivat lupaavia: molekyylikirjastojen seulonnoissa löytyi yksi TGF-β-perheen signalointiin vaikuttava yhdiste, jolla pystyttiin osoittamaan biologisesti merkittäviä antifibroottisia vaikutuksia keuhkofibroosin hiirimallissa

The brine and gas content of sea ice with attention to low salinities and high temperatures

Based on the well known sea ice phase diagram, equations are derived for determining the brine and gas content of sea Ice for high temperatures (range 0 to -2 °C) and low salinities. The presently widely used equations of Cox and Weeks (1982) are valid only for temperatures below -2°C. Fresh-water ice is used as a boundary condition for the equations. The relative salt concentrations in brine are_assumed to be the same as in normal (or standard) seawater. Two sets of equations are presented: 1) accurate formulae based on UNESCO standard sea water equations, and 2) approximate formulae based on general properties of weak solutions. The approximate formulae are not essentially different from the classical system which basically assumes the freezing point to be a linear function of fractional salt content. The agreement between the two approaches is excellent and the approximate system is good enough for most applications

Kymijoen jääolosuhteet ja veden laatu

In this paper we will present results from field measurements at the River Kymijoki gathered during winter 2011/2012. River Kymijoki research project was started in fall 2011 and these results are part of the results that were made for master’s thesis of Tom Kokkonen. River Kymijoki is located in southeast Finland, it freezes annually, and the catchment area of the river is 37 107 km2 which is about 11 % of the area of Finland. The lake percentage of the river catchment is 19 %. Aim of this first stage of the research project was to select measurement points and evaluate their suitability to present the River Kymijoki ice and water quality phenomena. Other goal for the project was to examine the collected data and process a comprehensive image of the River Kymijoki ice phenomena and water quality.Non peer reviewe

Ice Phenology in Eurasian Lakes over Spatial Location and Altitude

Eurasian freezing lakes cover an almost 180° wide longitude sector between the latitudes 30° and 75° N, and their altitudes range from below the sea surface level up to 5 km elevation. Ice phenology varies widely in this region. However, these variations and their influence factors have been little studied. Analytic models are applied here to examine these variations supported by historical ice and weather data. These models are forced by a linear air–lake heat exchange formula based on local empirical fits. The weather brings latitude–longitude–altitude patterns to the large-scale lake ice phenology. Freezing and breakup dates are forced by the local air temperature and solar radiation, and their rates of change are also important. In addition, freezing depends on lake depth and breakup depends on accumulated ice thickness. Lake depth provides a lag and radiation balance provides a shift with respect to the air temperature in cooling of the lake, and breakup is dictated by spring warming conditions and ice thickness. Due to solar radiation forcing, the common degree-day approach is biased for modelling ice phenology, especially in low latitudes. Analytic models provide a first-order tool for climate sensitivity of ice seasons. The freezing date and breakup date both change by around five days per one-degree shift in air temperature away from the climatological ice margin; however, at this margin, the sensitivity is higher

Ice Phenology in Eurasian Lakes over Spatial Location and Altitude

Eurasian freezing lakes cover an almost 180° wide longitude sector between the latitudes 30° and 75° N, and their altitudes range from below the sea surface level up to 5 km elevation. Ice phenology varies widely in this region. However, these variations and their influence factors have been little studied. Analytic models are applied here to examine these variations supported by historical ice and weather data. These models are forced by a linear air–lake heat exchange formula based on local empirical fits. The weather brings latitude–longitude–altitude patterns to the large-scale lake ice phenology. Freezing and breakup dates are forced by the local air temperature and solar radiation, and their rates of change are also important. In addition, freezing depends on lake depth and breakup depends on accumulated ice thickness. Lake depth provides a lag and radiation balance provides a shift with respect to the air temperature in cooling of the lake, and breakup is dictated by spring warming conditions and ice thickness. Due to solar radiation forcing, the common degree-day approach is biased for modelling ice phenology, especially in low latitudes. Analytic models provide a first-order tool for climate sensitivity of ice seasons. The freezing date and breakup date both change by around five days per one-degree shift in air temperature away from the climatological ice margin; however, at this margin, the sensitivity is higher

Interannual variability and trends in winter weather and snow conditions in Finnish Lapland

The interannual variability of the air temperature, precipitation and snow conditions were examined in the Finnish Arctic region based on data from the period 1946-2012. The purpose of this work was to describe the climatology of the region and to examine long-term variations in the climatic parameters. This information is essential for both environmental and socioeconomic aspects of the Finnish Arctic region. The air temperature, precipitation and snow depth records from nine weather stations were analysed in order to study the evolution of the winter duration (sub-zero temperature days), precipitation, snow cover duration and snow depth. The climatological description was based on the most recent 30-year period record available (1982-2011). Since 1946, air temperature has increased significantly by 0.4 degrees C/decade. Significant precipitation trends reached up to 35 mm/decade. For the most part there were no significant trends in snow depth and snow cover duration.Peer reviewe

Seasonal and annual heat budgets offshore the Hanko Peninsula, Gulf of Finland

Peer reviewe

Evolution of snow cover and dynamics of atmospheric deposits in the snow in the Antarctica. Data report

Field programme on the surface layer of the ice sheet in the Dronning Maud Land, Antarctica has been performed in 2009-2011. The objectives were to examine the annual accumulation and sublimation history, snow melting, chemistry of snow impurities, and life history of supraglacial and epiglacial lakes in blue ice regions. Fieldwork was done during FINNARP 2009 and 2010 expeditions. The sites were at the Finnish research station Aboa (73 02.5'S, 013 24.4'W), a snow line from Rampen at the edge of the ice shelf pass Aboa to the station Svea, and blue ice at Basen and neighboring nunataks. Snow measurements were made using classical snow pit method, ice and snow sampling, and with automatic observation stations (surface radiation balance, penetration of sunlight into snow and ice, and temperature within the surface layer of snow and ice). Life history, physics, and ecological state of lakes were mapped. This document is the data report including a brief project introduction, descriptions of the experiments, and the data obtained