Transfer of Natural Radionuclides in Terrestrial Food Chains—A Review of Investigations in Finland

Transfer of natural radionuclides 210Pb, 210Po, 238U, and 228,230,232Th in subarctic food chains has been studied in Finland since the 1960s. The unique food chain lichen-reindeer-man related to Sami people in Finnish Lapland and other food chain options, from berries or mushrooms to man, have been explored and the activity concentrations of natural radionuclides in biological samples determined. The results from Finnish radioecological studies are summarized and differences in bioaccumulation between different radionuclides are discussed. It was found out that, although a substantial amount of activity concentration data exist from the research projects executed in Finland during the last 6 decades, more data, especially from U and Th, in biological environment and humans would be useful, e.g., for modeling purposes and for improved assessment of bioaccumulation and adverse effects (both radiological and chemical) of radionuclides

Separation method for Pu, Am and Sr in large air filter sample sets

Peer reviewe

Measurements and modeling of airborne plutonium in Subarctic Finland between 1965 and 2011

The activity concentrations of Pu-238,Pu-239,Pu-240 and Am-241 (for determining its mother nuclide, Pu-241) as well as activity ratios of Pu-238/Pu239+240, Pu-241/Pu239+240 and Pu239+240/Cs-137 and the mass ratio of Pu-240/Pu-239 were determined from air filter samples collected in Rovaniemi (Finnish Lapland) in 1965 to 2011. The origin of plutonium in surface air was assessed based on these data from long time series. The most important Pu sources in the surface air of Rovaniemi were atmospheric nuclear-weapon testing in the 1950s and 1960s, later nuclear tests in 1973-1980 and the SNAP-9A satellite accident in 1964, whereas the influence from the 1986 Chernobyl accident was only minor. Contrary to the alpha-emitting Pu isotopes, Pu-241 from the Fukushima accident in 2011 was detected in Rovaniemi. Dispersion modeling results with the SILAM (System for Integrated modeLling of Atmospheric composition) model indicate that Pu contamination in northern Finland due to hypothetical reactor accidents would be negligible in the case of a floating reactor in the Shtokman natural gas field and relatively low in the case of an intended nuclear power plant in western Finland.Peer reviewe

241Pu and 241Pu/239+240Pu activity ratio in environmental samples from Finland as evaluated by the ingrowth of 241Am

Peer reviewe

How can sound strategic control and performance measurement be created in Russian and non-profit context? : Fitting the balanced scorecard to the needs of non-profit organization active in Russia

Siirretty Doriast

Novel Functions of ErbB4 and NRG-1 in Development and Cancer

Cells communicate, or signal, with each other constantly to ensure proper functioning of tissues and organs. Cell signaling is often performed by interplay of receptors and ligands that bind these receptors. ErbB receptors (epidermal growth factor receptors, EGFR, HER) bind extracellular growth factors and transduce these signals inside of cells. ErbB dysfunction promotes carcinogenesis, and also results in numerous defects during normal development. This study focused on the functions of one member of the ErbB receptor family, ErbB4, and growth factor, neuregulin-1 (NRG-1), that can bind and activate ErbB4. This study aimed to find novel functions of ErbB4 and NRG-1. Hypoxia, or deficiency of oxygen, is common in cancer and ischemic conditions. One of the key findings of the work was the identification and characterization of a cross-talk between ErbB4 and Hypoxia-inducible factor 1α (HIF-1α), the central mediator of hypoxia signaling. ErbB4 activation by NRG-1 was found to increase HIF-1α activity. Interestingly, this regulation occurred in reciprocal manner as HIF-1α was also able to increase protein levels of NRG-1 and ErbB4. Moreover, expression of NRG-1 and ErbB4 was associated with HIF activity in vivo in human clinical samples and in mice. Reduction of functional ErbB4 in developing zebrafish embryos resulted in defects in development of the skeletal muscles. To study ErbB4 functions in pathological situation in humans, clinical samples of serous ovarian carcinoma were analyzed using tissue microarrays and real-time RT-PCR. A specific isoform of ErbB4, CYT-1, was associated with poor survival in serous ovarian cancer and increased anchorage independent growth of ovarian cancer cells in vitro. These observations demonstrate that ErbB4 and NRG-1 are essential regulators of cellular response to hypoxia, of development, and of ovarian carcinogenesis.Elimistön solut viestivät keskenään normaalin kehityksen ja aikuisten kudosten normaalin toiminnan aikana. Tämä viestintä varmistaa solujen ympäristöönsä soveltuvan toiminnan. Soluviestintää välittävät reseptorit ja niihin sitoutuvat ligandit. ErbB (epidermaalisen kasvutekijän reseptorit, EGFR, HER) reseptorit sitovat solunulkoisia kasvutekijöitä, ja välittävät viestin solun sisälle. Monissa syövissä ErbB reseptorien toiminnan säätely on häiriintynyt. Tämä tutkimus keskittyi erään ErbB reseptorin, ErbB4:n, ja sen ligandin NRG-1:n toimintaan. Tutkimuksen päämääränä oli löytää uusia ErbB4:n ja NRG-1:n säätelemiä prosesseja ja niiden toimintamekanismeja. Hapenpuutetta, hypoksiaa, esiintyy monissa syövissä ja iskeemisissä tautitiloissa. Tutkimuksessa löytyi yhteys ErbB4:n välittämän viestinnän ja kes¬keisen hapen vähyyden viestijän (hypoksian indusoima tekijä 1α, HIF-1α) välillä. NRG-1 ja ErbB4 lisäsivät HIF-1α:n määrää ja aktiivisuutta. Tämä vuorovaikutus oli molemminpuolis¬ta, sillä myös HIF-1α:n aktiivisuus johti lisääntyneeseen NRG-1- ja ErbB4-määrään. Lisäksi lisääntynyt HIF-aktiivisuus oli yhteydessä lisääntyneeseen ErbB4:n ja NRG-1:n määrään kliinisissä näytteissä ja hiirimalleissa. ErbB4:n toiminnan estäminen seeprakalan alkiois¬sa johti luurankolihasten kehityksen häiriöihin. ErbB4:n toiminnan tutkimiseksi ihmisissä analysoitiin seröösin munasarjasyövän potilasnäytteitä kudossiruja sekä reaaliaikaista RT-PCR:ää käyttäen. ErbB4:n erityisen CYT-1 isomuodon ilmentyminen oli yhteydessä huonoon ennusteeseen seröösissä munasarjasyövässä sekä lisäsi munasarjasyöpäsolujen kasvua in vitro. Tutkimuksessa tehdyt havainnot viittaavat siihen, että NRG-1 ja ErbB4 ovat tärkeitä säätelijöitä solujen reagoimisessa hapenpuutteseen, kudosten kehittymisessä sekä seröösissä munasarjasyövässä.Siirretty Doriast