98 research outputs found

    Spatio-temporal impact of salinated mine water on Lake JormasjÀrvi, Finland

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    The salinization of freshwater environments is a global concern, and one of the largest sources of salinated water is the mining industry. An increasing number of modern mines are working with low grade sulfide ores, resulting in increased volumes of potentially harmful saline drainage. We used water monitoring data, together with data on sedimentary fossil remains (cladoceran, diatom and chironomid), to analyze the spatio-temporal (5 sampling locations and 3 sediment depths) impact of salinated mine water originating from the Talvivaara/Terrafame open cast mine on multiple components of the aquatic ecosystem of Lake JormasjÀrvi, Finland. Lake JormasjÀrvi is the fourth and largest lake in a chain of lakes along the path of the mine water. Despite the location and large water volume, the mine water has changed the chemistry of Lake JormasjÀrvi, reflected in increased electrical conductivity values since 2010. The ecological impact is significant around the inflow region of the lake, as all biological indicator groups show a rapid and directional shift towards new species composition. There is a clear trend in improved water quality as one moves further from the point of inflow, and as one looks back in time. Our results show that salinated mine water may induce rapid and large scale changes, even far downstream along a chain of several sinking basins. This is of special importance in cases where large amounts of waste water are processed in the vicinity of protected habitats.Peer reviewe

    Waste water discharge from a large Ni-Zn open cast mine degrades benthic integrity of Lake NuasjÀrvi (Finland)

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    The Talvivaara/Terrafame multi-metal mining company is Europe’s largest nickel open cast mine, it is also known for the largest wastewater leakage in the Finnish mining history and a series of other accidents. In this paleolimnological study, influences of a recently constructed treated waste water discharge pipeline into Lake NuasjĂ€rvi were investigated by analyzing past (pre-disturbance) and present community compositions of key aquatic organism groups, including diatoms, Cladocera and Chironomidae, along spatial (distance, water depth) gradients. In addition to defining ecological changes and impacts of saline mine waters in the lake, chironomids were used to quantitatively reconstruct bottom water oxygen conditions before and after the pipe installation (in 2015). The diatom and cladoceran communities, which reflect more the open-water habitat, showed only relatively minor changes throughout the lake, but a general decrease in diversity was observed within both groups. Chironomids, which live on substrates, showed more significant changes, including complete faunal turnovers and deteriorated benthic quality, especially at the sites close to the pipe outlet, where also chironomid diversity was almost completely lost. Furthermore, the reconstructed hypolimnetic oxygen values indicated a major oxygen decline and even anoxia at the sites near the pipe outlet. The limnoecological influence of the pipe decreased at sites located counter-flow or behind underwater barriers suggesting that the waste waters currently have location-specific impacts. Our study clearly demonstrates that whereas the upper water layers appear to have generally maintained their previous state, the deep-water layers close to the pipe outlet have lost their ecological integrity. Furthermore, the current hypolimnetic anoxia close to the pipe indicates enhanced lake stratification caused by the salinated mine waters. This study clearly exhibits the need to investigate different water bodies at several trophic levels in a spatiotemporal context to be able to reliably assess limnoecological impacts of mining.Peer reviewe

    AsiakaslÀhtöinen Toimintakykyni-sovellus : KehittÀminen ja kÀytettÀvyystutkimus

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    Tausta: Asiakkaan toimintakyvyn arviointi on tÀrkeÀ, toistuva ja aikaa vievÀ vaihe asiakkaan hakeutuessa sote-palveluihin. Asiakkaat kokevat asioidensa toistamisen useampaan kertaan turhauttavaksi. Kelan kehittÀmisrahaston rahoittamassa THL:n, Invalidiliiton ja JyvÀskylÀn Ammattikorkeakoulun yhteistyöhankkeessa kehitettiin asiakkaille prototyyppi toimintakyvyn itsearviointia helpottavasta sovelluksesta ja testattiin sen kÀytettÀvyyttÀ. Sovelluksen työnimi oli mobiili ICanFunction (mICF, suomeksi Toimintakykyni). MenetelmÀt: Asiakkaan kÀyttöliittymÀÀ kehitettiin erikseen aikuisten (n = 47) ja lasten (n = 11) palvelumuotoilutyöpajoissa. Useista lÀhteistÀ koottu arkikielinen sisÀltö sillattiin ICF-luokkiin. SisÀllön yllÀpitoa ja sovelluksessa nÀyttÀmistÀ varten luotiin FunctionMapper-metatietokanta THL:n Termieditoriin. Standardoidut fyysisen toimintakyvyn PROMIS-mittari aikuisille ja liikkumisen PROMIS-mittari lapsille kÀÀnnettiin suomeksi ja aikuisten mittari liitettiin sovellukseen. Koodaus toteutettiin standardien pohjalta ja kehitysversion 0.0.12 sai ladattua Playkaupasta tai Appstoresta omiin mobiililaitteisiin. Lapset (n = 11) sekÀ nuoret ja aikuiset (n = 19) kÀyttivÀt sitÀ noin viikon ajan, jonka jÀlkeen heidÀn kokemuksiaan sovelluksen kÀytettÀvyydestÀ kerÀttiin haastatteluilla. Lyhytkasvuisten henkilöiden (n = 13) toimintakyky-tietoa verrattiin LYHTY-tutkimuksen toimintakykyaineistoon. Tulokset: Sovelluksen avulla kÀyttÀjÀ voi valita tÀrkeÀksi kokemiaan aiheita ja kuvailla valitsemiaan toimintakykyyn tai ympÀristötekijöihin liittyviÀ asioita asteikolla, sanallisesti tai valokuvilla. KÀyttÀjÀ sai tÀyttÀmistÀÀn tiedoista yhteenvedon, jota hÀn voi nÀyttÀÀ ammattilaiselle. Aikuiset ja nuoret kokivat Toimintakykyni-sovelluksen hyvÀksyttÀvÀksi. He kÀyttÀisivÀt sitÀ hakemusten teossa tai sote-palveluihin mennessÀÀn, jos se olisi liitetty niihin. Se koettiin helppokÀyttöiseksi, mutta kÀyttömukavuus paranisi sovelluksen navigointia ja virheitÀ korjaamalla. He toivoivat sovellukseen alkuopastusta, visuaalisempaa yhteenvetoa ja mahdollisuutta seurata omassa tilanteessaan tapahtuvia muutoksia. Omaa arkitilannettaan he eivÀt voineet jakaa ammattilaisille, koska se koettiin keskenerÀiseksi ja irralliseksi palveluista. Lapset kÀyttivÀt sovellusta innostuneesti. He pitivÀt sitÀ todella hyvÀnÀ vÀlineenÀ saada oma ÀÀnensÀ kuuluviin. JohtopÀÀtökset: Lopputuloksena syntyi Toimintakykyni-sovelluksen prototyyppi, joka mahdollisti asiakkaalle yksilöllisen ja monipuolisen sekÀ samalla rakenteisen toimintakykytiedon kuvaamisen. Aikuiset, nuoret ja lapset hyvÀksyivÀt sen ja pitivÀt sitÀ hyödyllisenÀ ja helppokÀyttöisenÀ. He pystyivÀt kuvaamaan sovelluksen avulla elÀmÀntilannettaan yksilöllisesti, mutta sovelluksen kÀsitteitÀ tulisi kehittÀÀ lisÀÀ. Asiakkaat kÀyttÀisivÀt sovellusta erityisesti, jos se liitettÀisiin moniin palveluihin. Jatkossa pitÀÀ varmistaa, ettÀ asiakkaiden kehitysehdotukset otetaan huomioon ja ettÀ sovelluksesta kehitetÀÀn yhteys sosiaali- ja terveydenhuollon tietojÀrjestelmiin. Asiakkaiden raportoima tieto tulisi ottaa huomioon palveluiden suunnittelussa ja seurannassa, jotta asiakkaat saisivat sovelluksen kÀytöstÀ tÀyden hyödyn

    AsiakaslÀhtöinen Toimintakykyni-sovellus. KehittÀminen ja kÀytettÀvyystutkimus

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    62 s.Tausta: Asiakkaan toimintakyvyn arviointi on tÀrkeÀ, toistuva ja aikaa vievÀ vaihe asiakkaan hakeutuessa sote-palveluihin. Asiakkaat kokevat asioidensa toistamisen useampaan kertaan turhauttavaksi. Kelan kehittÀmisrahaston rahoittamassa THL:n, Invalidiliiton ja JyvÀskylÀn Ammattikorkeakoulun yhteistyöhankkeessa kehitettiin asiakkaille prototyyppi toimintakyvyn itsearviointia helpottavasta sovelluksesta ja testattiin sen kÀytettÀvyyttÀ. Sovelluksen työnimi oli mobiili ICanFunction (mICF, suomeksi Toimintakykyni). MenetelmÀt: Asiakkaan kÀyttöliittymÀÀ kehitettiin erikseen aikuisten (n = 47) ja lasten (n = 11) palvelumuotoilutyöpajoissa. Useista lÀhteistÀ koottu arkikielinen sisÀltö sillattiin ICF-luokkiin. SisÀllön yllÀpitoa ja sovelluksessa nÀyttÀmistÀ varten luotiin FunctionMapper-metatietokanta THL:n Termieditoriin. Standardoidut fyysisen toimintakyvyn PROMIS-mittari aikuisille ja liikkumisen PROMIS-mittari lapsille kÀÀnnettiin suomeksi ja aikuisten mittari liitettiin sovellukseen. Koodaus toteutettiin standardien pohjalta ja kehitysversion 0.0.12 sai ladattua Playkaupasta tai Appstoresta omiin mobiililaitteisiin. Lapset (n = 11) sekÀ nuoret ja aikuiset (n = 19) kÀyttivÀt sitÀ noin viikon ajan, jonka jÀlkeen heidÀn kokemuksiaan sovelluksen kÀytettÀvyydestÀ kerÀttiin haastatteluilla. Lyhytkasvuisten henkilöiden (n = 13) toimintakyky-tietoa verrattiin LYHTY-tutkimuksen toimintakykyaineistoon. Tulokset: Sovelluksen avulla kÀyttÀjÀ voi valita tÀrkeÀksi kokemiaan aiheita ja kuvailla valitsemiaan toimintakykyyn tai ympÀristötekijöihin liittyviÀ asioita asteikolla, sanallisesti tai valokuvilla. KÀyttÀjÀ sai tÀyttÀmistÀÀn tiedoista yhteenvedon, jota hÀn voi nÀyttÀÀ ammattilaiselle. Aikuiset ja nuoret kokivat Toimintakykyni-sovelluksen hyvÀksyttÀvÀksi. He kÀyttÀisivÀt sitÀ hakemusten teossa tai sote-palveluihin mennessÀÀn, jos se olisi liitetty niihin. Se koettiin helppokÀyttöiseksi, mutta kÀyttömukavuus paranisi sovelluksen navigointia ja virheitÀ korjaamalla. He toivoivat sovellukseen alkuopastusta, visuaalisempaa yhteenvetoa ja mahdollisuutta seurata omassa tilanteessaan tapahtuvia muutoksia. Omaa arkitilannettaan he eivÀt voineet jakaa ammattilaisille, koska se koettiin keskenerÀiseksi ja irralliseksi palveluista. Lapset kÀyttivÀt sovellusta innostuneesti. He pitivÀt sitÀ todella hyvÀnÀ vÀlineenÀ saada oma ÀÀnensÀ kuuluviin. JohtopÀÀtökset: Lopputuloksena syntyi Toimintakykyni-sovelluksen prototyyppi, joka mahdollisti asiakkaalle yksilöllisen ja monipuolisen sekÀ samalla rakenteisen toimintakykytiedon kuvaamisen. Aikuiset, nuoret ja lapset hyvÀksyivÀt sen ja pitivÀt sitÀ hyödyllisenÀ ja helppokÀyttöisenÀ. He pystyivÀt kuvaamaan sovelluksen avulla elÀmÀntilannettaan yksilöllisesti, mutta sovelluksen kÀsitteitÀ tulisi kehittÀÀ lisÀÀ. Asiakkaat kÀyttÀisivÀt sovellusta erityisesti, jos se liitettÀisiin moniin palveluihin. Jatkossa pitÀÀ varmistaa, ettÀ asiakkaiden kehitysehdotukset otetaan huomioon ja ettÀ sovelluksesta kehitetÀÀn yhteys sosiaali- ja terveydenhuollon tietojÀrjestelmiin. Asiakkaiden raportoima tieto tulisi ottaa huomioon palveluiden suunnittelussa ja seurannassa, jotta asiakkaat saisivat sovelluksen kÀytöstÀ tÀyden hyödyn

    Warm summers and rich biotic communities during N-Hemisphere deglaciation

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    Detailed studies on fossil remains of plants or animals in glacial lake sediments are rare. As a result, environmental conditions right at the moment of deglaciation of the large N-Hemisphere ice-sheets remain largely unknown. Here we study three deglacial phases of the Fennoscandian Ice Sheet as a unique, repeated element in a long sediment record preserved at Sokli in northern Finland. We summarize extensive multi-proxy data (diatoms, phytoliths, chironomids, pollen, spores, non-pollen palynomorphs, macrofossils, lithology, loss-on-ignition, C/N) obtained on glacial lake sediments dated to the early Holocene (ca. 10 kyr BP), early MIS 3 (ca. 50 kyr BP) and early MIS 5a (ca. 80 kyr BP). In contrast to the common view of an unproductive ice-marginal environment, our study reconstructs rich ecosystems both in the glacial lake and along the shores with forest on recently deglaciated land. Higher than present-day summer temperatures are reconstructed based on a large variety of aquatic taxa. Rich biota developed due to the insolation-induced postglacial warming and high nutrient levels, the latter resulting from erosion of fresh bedrock and sediment, leaching of surface soils, decay of plant material under shallow water conditions, and sudden decreases in lake volume. Aquatic communities responded quickly to deglaciation and warm summers and reflect boreal conditions, in contrast to the terrestrial ecosystem which responded with some delay probably due to time required for slow soil formation processes. Birch forest is reconstructed upon deglaciation of the large LGM ice-sheet and shrub tundra following the probably faster melting smaller MIS 4 and MIS 5b ice-sheets. Our study shows that glacial lake sediments can provide valuable palaeo-environmental data, that aquatic biota and terrestrial vegetation rapidly accommodated to new environmental conditions during deglaciation, and that glacial lake ecosystems, and the carbon stored in their sediments, should be included in earth system modeling.Peer reviewe

    Comparison of quantitative Holocene temperature reconstructions using multiple proxies from a northern boreal lake

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    Four biotic proxies (plant macrofossils, pollen, chironomids and diatoms) are employed to quantitatively reconstruct variations in mean July air temperatures (T-jul) at Lake Loitsana (northern Finland) during the Holocene. The aim is to evaluate the robustness and biases in these temperature reconstructions and to compare the timing of highest T-jul in the individual reconstructions. The reconstructed T-jul values are evaluated in relation to local-scale/site-specific processes associated with the Holocene lake development at Loitsana as these factors have been shown to significantly influence the fossil assemblages found in the Lake Loitsana sediments. While pollen-based temperatures follow the classical trend of gradually increasing early-Holocene T-jul with a mid-Holocene maximum, the aquatic/wetland assemblages reconstruct higher-than-present T-jul already during the early Holocene, that is, at the peak of summer insolation. The relatively low early-Holocene July temperatures recorded by the pollen are the result of site-specific factors possibly combined with a delayed response of the terrestrial ecosystem compared with the aquatic ecosystem. Our study shows that all reconstructions are influenced at least to some extent by local factors. This finding stresses the need to evaluate quantitatively reconstructed climate values against local lake development and highlights the benefit of using multi-proxy data in Holocene climate reconstructions.Peer reviewe

    Effect of Temperature on the Size of Sedimentary Remains of Littoral Chydorids

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    The body size of aquatic invertebrates is, to a great extent, dependent on ambient temperature, but size distributions are also determined by other factors like food supply and predation. The effect of temperature on organisms is formulated in the temperature–size hypothesis, which predicts a smaller body size with increasing temperature. In this study, the effect of temperature on the subfossil remains of three littoral Cladocera (Alona affnis, A. quadrangularis, and Chydorus cf. sphaericus) was investigated. Exoskeletal remains of these species can be found in large numbers in lacustrine sediments and over a wide north–south range in Europe. The total length of both headshield and postabdomen for A. affinis and A. quadrangularis and carapace length for C. cf. sphaericus were measured to observe their response to changes in latitude and temperature. A different response to ambient temperature in the growth of body parts was observed. The size of the headshields of both Alona species and of the carapace of Chydorus was significantly larger in colder regions as opposed to warm ones. It turned out that the postabdomen was not a good predictor of ambient temperature. While the sizes of all remains increased with latitude, the sizes of the Alona remains was smaller in the mountain lakes of the Southern Carpathians than in other cold lakes, in this case in Finland, a fact indicative of the importance of other factors on size distribution. This study demonstrates that a morphological response to climate is present in littoral cladocerans, and, therefore, changes in the length of headshield and carapace may be used as a proxy for climate changes in paleolimnological records

    Inferring past trends in lake water organic carbon concentrations in northern lakes using sediment spectroscopy

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    Changing lake water total organic carbon (TOC)concentrations are of concern for lake management because of corresponding effects on aquatic ecosystem functioning, drinking water resources and carbon cycling between land and sea. Understanding the importance of human activities on TOC changes requires knowledge of past concentrations; however, water-monitoring data are typically only available for the past few decades, if at all. Here, we present a universal model to infer past lake water TOC concentrations in northern lakes across Europe and North America that uses visible-near-infrared (VNIR) spectroscopy on lake sediments. In the orthogonal partial least squares model, VNIR spectra of surface-sediment samples are calibrated against corresponding surface-water TOC concentrations (0.5–41 mg L-1) from 345 Arctic to northern temperate lakes in Canada, Greenland, Sweden and Finland. Internal model-cross-validation resulted in a R2 of 0.57 and a prediction error of 4.4 mg TOC L-1. First applications to lakes in southern Ontario and Scotland, which are outside of the model’s geographic range, show the model accurately captures monitoring trends, and suggests that TOC dynamics during the 20th century at these sites were primarily driven by changes in atmospheric deposition. Our results demonstrate that the lake-water TOC model has multi-regional applications and is not biased by post-depositional diagenesis, allowing the identification of past TOC variations in northern lakes of Europe and North America over timescales of decades to millennia

    Visual Coding in Locust Photoreceptors

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    Information capture by photoreceptors ultimately limits the quality of visual processing in the brain. Using conventional sharp microelectrodes, we studied how locust photoreceptors encode random (white-noise, WN) and naturalistic (1/f stimuli, NS) light patterns in vivo and how this coding changes with mean illumination and ambient temperature. We also examined the role of their plasma membrane in shaping voltage responses. We found that brightening or warming increase and accelerate voltage responses, but reduce noise, enabling photoreceptors to encode more information. For WN stimuli, this was accompanied by broadening of the linear frequency range. On the contrary, with NS the signaling took place within a constant bandwidth, possibly revealing a ‘preference’ for inputs with 1/f statistics. The faster signaling was caused by acceleration of the elementary phototransduction current - leading to bumps - and their distribution. The membrane linearly translated phototransduction currents into voltage responses without limiting the throughput of these messages. As the bumps reflected fast changes in membrane resistance, the data suggest that their shape is predominantly driven by fast changes in the light-gated conductance. On the other hand, the slower bump latency distribution is likely to represent slower enzymatic intracellular reactions. Furthermore, the Q10s of bump duration and latency distribution depended on light intensity. Altogether, this study suggests that biochemical constraints imposed upon signaling change continuously as locust photoreceptors adapt to environmental light and temperature conditions
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