53 resultados para Locally Nilpotent Derivations
Resumo:
In nature, variation for example in herbivory, wind exposure, moisture and pollution impact often creates variation in physiological stress and plant productivity. This variation is seldom clear-cut, but rather results in clines of decreasing growth and productivity towards the high-stress end. These clines of unidirectionally changing stress are generally known as ‘stress gradients’. Through its effect on plant performance, stress has the capacity to fundamentally alter the ecological relationships between individuals, and through variation in survival and reproduction it also causes evolutionary change, i.e. local adaptations to stress and eventually speciation. In certain conditions local adaptations to environmental stress have been documented in a matter of just a few generations. In plant-plant interactions, intensities of both negative interactions (competition) and positive ones (facilitation) are expected to vary along stress gradients. The stress-gradient hypothesis (SGH) suggests that net facilitation will be strongest in conditions of high biotic and abiotic stress, while a more recent ‘humpback’ model predicts strongest net facilitation at intermediate levels of stress. Plant interactions on stress gradients, however, are affected by a multitude of confounding factors, making studies of facilitation-related theories challenging. Among these factors are plant ontogeny, spatial scale, and local adaptation to stress. The last of these has very rarely been included in facilitation studies, despite the potential co-occurrence of local adaptations and changes in net facilitation in stress gradients. Current theory would predict both competitive effects and facilitative responses to be weakest in populations locally adapted to withstand high abiotic stress. This thesis is based on six experiments, conducted both in greenhouses and in the field in Russia, Norway and Finland, with mountain birch (Betula pubescens subsp. czerepanovii) as the model species. The aims were to study potential local adaptations in multiple stress gradients (both natural and anthropogenic), changes in plant-plant interactions under conditions of varying stress (as predicted by SGH), potential mechanisms behind intraspecific facilitation, and factors confounding plant-plant facilitation, such as spatiotemporal, ontogenetic, and genetic differences. I found rapid evolutionary adaptations (occurring within a time-span of 60 to 70 years) towards heavy-metal resistance around two copper-nickel smelters, a phenomenon that has resulted in a trade-off of decreased performance in pristine conditions. Heavy-metal-adapted individuals had lowered nickel uptake, indicating a possible mechanism behind the detected resistance. Seedlings adapted to heavy-metal toxicity were not co-resistant to others forms of abiotic stress, but showed co-resistance to biotic stress by being consumed to a lesser extent by insect herbivores. Conversely, populations from conditions of high natural stress (wind, drought etc.) showed no local adaptations, despite much longer evolutionary time scales. Due to decreasing emissions, I was unable to test SGH in the pollution gradients. In natural stress gradients, however, plant performance was in accordance with SGH, with the strongest host-seedling facilitation found at the high-stress sites in two different stress gradients. Factors confounding this pattern included (1) plant size / ontogenetic status, with seedling-seedling interactions being competition dominated and host-seedling interactions potentially switching towards competition with seedling growth, and (2) spatial distance, with competition dominating at very short planting distances, and facilitation being strongest at a distance of circa ¼ benefactor height. I found no evidence for changes in facilitation with respect to the evolutionary histories of plant populations. Despite the support for SGH, it may be that the ‘humpback’ model is more relevant when the main stressor is resource-related, while what I studied were the effects of ‘non-resource’ stressors (i.e. heavy-metal pollution and wind). The results have potential practical applications: the utilisation of locally adapted seedlings and plant facilitation may increase the success of future restoration efforts in industrial barrens as well as in other wind-exposed sites. The findings also have implications with regard to the effects of global change in subarctic environments: the documented potential by mountain birch for rapid evolutionary change, together with the general lack of evolutionary ‘dead ends’, due to not (over)specialising to current natural conditions, increase the chances of this crucial forest-forming tree persisting even under the anticipated climate change.
Resumo:
Tässä kandidaatintyössä on käsitelty akkuja ja vetypolttokennoja sähköauton voimanlähteenä. Työssä on esitelty sähköautojen ja niiden voimanlähteiden teknologioiden periaatteita, energiankantajia, hyötysuhteita ja päästöjä. Lisäksi on tarkasteltu polttomoottorikäyttöisiä autotekniikoita vertailukohdan saamiseksi. Työn lopuksi on analysoitu sähköautojen markkinoita ja niiden yleistymiseen vaikuttavia tekijöitä. Sähköautot mahdollistavat vaihtoehtoisten energialähteiden käytön, joka antaa tilaisuuden saasteiden ja päästöjen keskitettyyn vähentämiseen ja talteenottoon. Niiden avulla päästään myös pois öljyriippuvuudesta ja paikallisesti aiheutuneista päästöistä. Nykyisten polttoaineiden helpon käsiteltävyyden, kohtuullisien energiatiheyksien ja laajojen infrastruktuurien vuoksi käytössä olevien tekniikoiden syrjäyttäminen on vaikeaa. Uusien tekniikoiden etuja ja haittoja voidaan tarkastella yksinkertaisilla metodeilla, kuten kustannusten, hyötysuhteiden, päästöjen ja polttoaineiden elinkaarien vertailulla. Vertailua vaikeuttaa tosin hintatasojen ja verotuksen eroavaisuudet eri maissa, ja se on siksi suoritettava osin maakohtaisesti. Suurimpia esteitä uusille tekniikoille ovat tällä hetkellä niiden tuomat lisäkustannukset, infrastruktuurien puuttuminen ja nykyisten polttoaineiden korvaaminen toisella.
Resumo:
This thesis deals with distance transforms which are a fundamental issue in image processing and computer vision. In this thesis, two new distance transforms for gray level images are presented. As a new application for distance transforms, they are applied to gray level image compression. The new distance transforms are both new extensions of the well known distance transform algorithm developed by Rosenfeld, Pfaltz and Lay. With some modification their algorithm which calculates a distance transform on binary images with a chosen kernel has been made to calculate a chessboard like distance transform with integer numbers (DTOCS) and a real value distance transform (EDTOCS) on gray level images. Both distance transforms, the DTOCS and EDTOCS, require only two passes over the graylevel image and are extremely simple to implement. Only two image buffers are needed: The original gray level image and the binary image which defines the region(s) of calculation. No other image buffers are needed even if more than one iteration round is performed. For large neighborhoods and complicated images the two pass distance algorithm has to be applied to the image more than once, typically 3 10 times. Different types of kernels can be adopted. It is important to notice that no other existing transform calculates the same kind of distance map as the DTOCS. All the other gray weighted distance function, GRAYMAT etc. algorithms find the minimum path joining two points by the smallest sum of gray levels or weighting the distance values directly by the gray levels in some manner. The DTOCS does not weight them that way. The DTOCS gives a weighted version of the chessboard distance map. The weights are not constant, but gray value differences of the original image. The difference between the DTOCS map and other distance transforms for gray level images is shown. The difference between the DTOCS and EDTOCS is that the EDTOCS calculates these gray level differences in a different way. It propagates local Euclidean distances inside a kernel. Analytical derivations of some results concerning the DTOCS and the EDTOCS are presented. Commonly distance transforms are used for feature extraction in pattern recognition and learning. Their use in image compression is very rare. This thesis introduces a new application area for distance transforms. Three new image compression algorithms based on the DTOCS and one based on the EDTOCS are presented. Control points, i.e. points that are considered fundamental for the reconstruction of the image, are selected from the gray level image using the DTOCS and the EDTOCS. The first group of methods select the maximas of the distance image to new control points and the second group of methods compare the DTOCS distance to binary image chessboard distance. The effect of applying threshold masks of different sizes along the threshold boundaries is studied. The time complexity of the compression algorithms is analyzed both analytically and experimentally. It is shown that the time complexity of the algorithms is independent of the number of control points, i.e. the compression ratio. Also a new morphological image decompression scheme is presented, the 8 kernels' method. Several decompressed images are presented. The best results are obtained using the Delaunay triangulation. The obtained image quality equals that of the DCT images with a 4 x 4
Resumo:
Pienkiinteistöjen öljyvahingot ovat viime vuosina lisääntyneet. Tämän työn tarkoituksena on luoda öljyvahingon torjuntaan ja jälkihoitoon osallistuvalle urakoitsijalle toimintamalli asuinkiinteistön öljyvahingon hoitamiseksi. Mallin halutaan erityisesti kuvaavan öljyvahingon hoitoon osallistuvien viranomaisten ja muiden tahojen vastuita ja velvollisuuksia. Työn tavoitteena on myös tunnistaa pienkiinteistöissä tapahtuvat öljyvahinkotyypit sekä niille altistavat riskitekijät. Öljyn päästäminen ympäristöön sekä öljyn käsittely ja varastointi niin, että siitä aiheutuu öljyvahingon vaara, kielletään laissa. Vahinkojen torjumiseksi on annettu määräyksiä muun muassa öljylämmityslaitteistojen turvallisuutta koskien. Asuinkiinteistöjen öljyvahingot liittyvät yleensä öljysäiliön täyttötilanteisiin. Vahinkojen syynä on usein säiliön ja sen varusteiden puutteellisuus tai huono kunto. Asuinrakennusten lämmitykseen käytetään kevyttä polttoöljyä. Maahan joutuessaan polttoöljy imeytyy sora- ja hiekkamaahan nopeasti, jolloin vaarana on öljyn kulkeutuminen pohjaveteen ja vesistöihin. Asuinkiinteistön öljyvahingossa öljyä joutuu usein myös rakenteisiin. Öljyvahingosta tulee ilmoittaa aina hätäkeskukseen. Vastuu öljyvahinkojen torjunnasta kuuluu alueelliselle pelastustoimelle. Torjuntatoimiin osallistuu usein myös urakoitsija. Jos vahinkokohdetta ei torjuntatoimin saada kunnostettua, alueellinen ympäristökeskus voi määrätä puhdistamisesta vastuussa olevan selvittämään pilaantuneen alueen laajuuden ja puhdistamistarpeen sekä toteuttamaan mahdollisen kunnostuksen. Pilaantuneen maaperän kunnostus voidaan toteuttaa massan vaihtona tai paikan päällä maata kaivamatta. Likaantuneiden rakenteiden saneerausta tarvitaan sisäilman hajuhaittojen poistamiseksi. Öljyvahingon kustannukset voivat nousta hyvinkin suuriksi. Ensisijainen vastuu niistä kuuluu vahingonaiheuttajalle.
Resumo:
Hormone-dependent diseases, e.g. cancers, rank high in mortality in the modern world, and thus, there is an urgent need for new drugs to treat these diseases. Although the diseases are clearly hormone-dependent, changes in circulating hormone concentrations do not explain all the pathological processes observed in the diseased tissues. A more inclusive explanation is provided by intracrinology – a regulation of hormone concentrations at the target tissue level. This is mediated by the expression of a pattern of steroid-activating and -inactivating enzymes in steroid target tissues, thus enabling a concentration gradient between the blood circulation and the tissue. Hydroxysteroid (17beta) dehydrogenases (HSD17Bs) form a family of enzymes that catalyze the conversion between low active 17-ketosteroids and highly active 17beta-hydroxysteroids. HSD17B1 converts low active estrogen (E1) to highly active estradiol (E2) with high catalytic efficiency, and altered HSD17B1 expression has been associated with several hormone-dependent diseases, including breast cancer, endometriosis, endometrial hyperplasia and cancer, and ovarian epithelial cancer. Because of its putative role in E2 biosynthesis in ovaries and peripheral target tissues, HSD17B1 is considered to be a promising drug target for estrogen-dependent diseases. A few studies have indicated that the enzyme also has androgenic activity, but they have been ignored. In the present study, transgenic mice overexpressing human HSD17B1 (HSD17B1TG mice) were used to study the effects of the enzyme in vivo. Firstly, the substrate specificity of human HSD17B1 was determined in vivo. The results indicated that human HSD17B1 has significant androgenic activity in female mice in vivo, which resulted in increased fetal testosterone concentration and female disorder of sexual development appearing as masculinized phenotype (increased anogenital distance, lack of nipples, lack of vaginal opening, combination of vagina with urethra, enlarged Wolffian duct remnants in the mesovarium and enlarged female prostate). Fetal androgen exposure has been linked to polycystic ovary syndrome (PCOS) and metabolic syndrome during adulthood in experimental animals and humans, but the genes involved in PCOS are largely unknown. A putative mechanism to accumulate androgens during fetal life by HSD17B1 overexpression was shown in the present study. Furthermore, as a result of prenatal androgen exposure locally in the ovaries, HSD17B1TG females developed ovarian benign serous cystadenomas in adulthood. These benign lesions are precursors of low-grade ovarian serous tumors. Ovarian cancer ranks fifth in mortality of all female cancers in Finland, and most of the ovarian cancers arise from the surface epithelium. The formation of the lesions was prevented by prenatal antiandrogen treatment and by transplanting wild type (WT) ovaries prepubertally into HSD17B1TG females. The results obtained in our non-clinical TG mouse model, together with a literature analysis, suggest that HSD17B1 has a role in ovarian epithelial carcinogenesis, and especially in the development of serous tumors. The role of androgens in ovarian carcinogenesis is considered controversial, but the present study provides further evidence for the androgen hypothesis. Moreover, it directly links HSD17B1-induced prenatal androgen exposure to ovarian epithelial carcinogenesis in mice. As expected, significant estrogenic activity was also detected for human HSD17B1. HSD17B1TG mice had enhanced peripheral conversion of E1 to E2 in a variety of target tissues, including the uterus. Furthermore, this activity was significantly decreased by treatments with specific HSD17B1 inhibitors. As a result, several estrogen-dependent disorders were found in HSD17B1TG females. Here we report that HSD17B1TG mice invariably developed endometrial hyperplasia and failed to ovulate in adulthood. As in humans, endometrial hyperplasia in HSD17B1TG females was reversible upon ovulation induction, triggering a rise in circulating progesterone levels, and in response to exogenous progestins. Remarkably, treatment with a HSD17B1 inhibitor failed to restore ovulation, yet completely reversed the hyperplastic morphology of epithelial cells in the glandular compartment. We also demonstrate that HSD17B1 is expressed in normal human endometrium, hyperplasia, and cancer. Collectively, our non-clinical data and literature analysis suggest that HSD17B1 inhibition could be one of several possible approaches to decrease endometrial estrogen production in endometrial hyperplasia and cancer. HSD17B1 expression has been found in bones of humans and rats. The non-clinical data in the present study suggest that human HSD17B1 is likely to have an important role in the regulation of bone formation, strength and length during reproductive years in female mice. Bone density in HSD17B1TG females was highly increased in femurs, but in lesser amounts also in tibias. Especially the tibia growth plate, but not other regions of bone, was susceptible to respond to HSD17B1 inhibition by increasing bone length, whereas the inhibitors did not affect bone density. Therefore, HSD17B1 inhibitors could be safer than aromatase inhibitors in regard to bone in the treatment of breast cancer and endometriosis. Furthermore, diseases related to improper growth, are a promising new indication for HSD17B1 inhibitors.
Resumo:
Tietotekniikan osaston osastokirjaston nykyinen varausjärjestelmä toimii paperilapuin merkittävin varauksin. Kirjojen lainaus- ja saatavuustilanne halutaan selkeämmäksi, sekä lainausprosessi helpommaksi. Työssä suunnitellaan varausjärjestelmä vanhan kirjojen hakuun jo olemassa olevan järjestelmän pohjalta, kaikki ohjelmakoodi kirjoitetaan kuitenkin uusiksi, jotta järjestelmä olisi yhtenäinen. Uusina toimintoina lisätään kirjojen varaus ja lainaus, sekä admin-käyttäjälle mahdollisuus tarkastella lainoja ja varauksia. Työn toteutuksessa edetessä sitä testataan jatkuvasti, ennen käyttöönottoa järjestelmää testataan oikeassa käyttöympäristössään. Työn tuloksena on järjestelmä, joka mahdollistaa kirjojen varaamisen ja lainaamisen sekä selkeyttää kirjojen lainaustilannetta. Lisäksi tässä dokumentissa selvitetään lyhyesti järjestelmän jatkokehitysmahdollisuuksia.
Resumo:
Genetic diversity is one of the levels of biodiversity that the World Conservation Union (IUCN) has recognized as being important to preserve. This is because genetic diversity is fundamental to the future evolution and to the adaptive flexibility of a species to respond to the inherently dynamic nature of the natural world. Therefore, the key to maintaining biodiversity and healthy ecosystems is to identify, monitor and maintain locally-adapted populations, along with their unique gene pools, upon which future adaptation depends. Thus, conservation genetics deals with the genetic factors that affect extinction risk and the genetic management regimes required to minimize the risk. The conservation of exploited species, such as salmonid fishes, is particularly challenging due to the conflicts between different interest groups. In this thesis, I conduct a series of conservation genetic studies on primarily Finnish populations of two salmonid fish species (European grayling, Thymallus thymallus, and lake-run brown trout, Salmo trutta) which are popular recreational game fishes in Finland. The general aim of these studies was to apply and develop population genetic approaches to assist conservation and sustainable harvest of these populations. The approaches applied included: i) the characterization of population genetic structure at national and local scales; ii) the identification of management units and the prioritization of populations for conservation based on evolutionary forces shaping indigenous gene pools; iii) the detection of population declines and the testing of the assumptions underlying these tests; and iv) the evaluation of the contribution of natural populations to a mixed stock fishery. Based on microsatellite analyses, clear genetic structuring of exploited Finnish grayling and brown trout populations was detected at both national and local scales. Finnish grayling were clustered into three genetically distinct groups, corresponding to northern, Baltic and south-eastern geographic areas of Finland. The genetic differentiation among and within population groups of grayling ranged from moderate to high levels. Such strong genetic structuring combined with low genetic diversity strongly indicates that genetic drift plays a major role in the evolution of grayling populations. Further analyses of European grayling covering the majority of the species’ distribution range indicated a strong global footprint of population decline. Using a coalescent approach the beginning of population reduction was dated back to 1 000-10 000 years ago (ca. 200-2 000 generations). Forward simulations demonstrated that the bottleneck footprints measured using the M ratio can persist within small populations much longer than previously anticipated in the face of low levels of gene flow. In contrast to the M ratio, two alternative methods for genetic bottleneck detection identified recent bottlenecks in six grayling populations that warrant future monitoring. Consistent with the predominant role of random genetic drift, the effective population size (Ne) estimates of all grayling populations were very low with the majority of Ne estimates below 50. Taken together, highly structured local populations, limited gene flow and the small Ne of grayling populations indicates that grayling populations are vulnerable to overexploitation and, hence, monitoring and careful management using the precautionary principles is required not only in Finland but throughout Europe. Population genetic analyses of lake-run brown trout populations in the Inari basin (northernmost Finland) revealed hierarchical population structure where individual populations were clustered into three population groups largely corresponding to different geographic regions of the basin. Similar to my earlier work with European grayling, the genetic differentiation among and within population groups of lake-run brown trout was relatively high. Such strong differentiation indicated that the power to determine the relative contribution of populations in mixed fisheries should be relatively high. Consistent with these expectations, high accuracy and precision in mixed stock analysis (MSA) simulations were observed. Application of MSA to indigenous fish caught in the Inari basin identified altogether twelve populations that contributed significantly to mixed stock fisheries with the Ivalojoki river system being the major contributor (70%) to the total catch. When the contribution of wild trout populations to the fisheries was evaluated regionally, geographically nearby populations were the main contributors to the local catches. MSA also revealed a clear separation between the lower and upper reaches of Ivalojoki river system – in contrast to lower reaches of the Ivalojoki river that contributed considerably to the catch, populations from the upper reaches of the Ivalojoki river system (>140 km from the river mouth) did not contribute significantly to the fishery. This could be related to the available habitat size but also associated with a resident type life history and increased cost of migration. The studies in my thesis highlight the importance of dense sampling and wide population coverage at the scale being studied and also demonstrate the importance of critical evaluation of the underlying assumptions of the population genetic models and methods used. These results have important implications for conservation and sustainable fisheries management of Finnish populations of European grayling and brown trout in the Inari basin.
Resumo:
Suomenlahden lisääntynyt meriliikenne on herättänyt huolta meriliikenteen turvallisuuden tasosta, ja erityisesti Venäjän öljyviennin kasvu on lisännyt öljyonnettomuuden todennäköisyyttä Suomenlahdella. Erilaiset kansainväliset, alueelliset ja kansalliset ohjauskeinot pyrkivät vähentämään merionnettomuuden riskiä ja meriliikenteen muita haittavaikutuksia. Tämä raportti käsittelee meriturvallisuuden yhteiskunnallisia ohjauskeinoja: ohjauskeinoja yleisellä tasolla, meriturvallisuuden keskeisimpiä säätelijöitä, meriturvallisuuden ohjauskeinoja ja meriturvallisuuspolitiikan tulevaisuuden näkymiä, ohjauskeinojen tehokkuutta ja nykyisen meriturvallisuuden ohjausjärjestelmän heikkouksia. Raportti on kirjallisuuskatsaus meriturvallisuuden yhteiskunnalliseen sääntelyn rakenteeseen ja tilaan erityisesti Suomenlahden meriliikenteen näkökulmasta. Raportti on osa tutkimusprojektia ”SAFGOF - Suomenlahden meriliikenteen kasvunäkymät 2007 - 2015 ja kasvun vaikutukset ympäristölle ja kuljetusketjujen toimintaan” ja sen työpakettia 6 ”Keskeisimmät riskit ja yhteiskunnalliset vaikutuskeinot”. Yhteiskunnalliset ohjauskeinot voidaan ryhmitellä hallinnollisiin, taloudellisiin ja tietoohjaukseen perustuviin ohjauskeinoihin. Meriturvallisuuden edistämisessä käytetään kaikkia näitä, mutta hallinnolliset ohjauskeinot ovat tärkeimmässä asemassa. Merenkulun kansainvälisen luonteen vuoksi meriturvallisuuden sääntely tapahtuu pääosin kansainvälisellä tasolla YK:n ja erityisesti Kansainvälisen merenkulkujärjestön (IMO) toimesta. Lisäksi myös Euroopan Unionilla on omaa meriturvallisuuteen liittyvää sääntelyä ja on myös olemassa muita alueellisia meriturvallisuuden edistämiseen liittyviä elimiä kuten HELCOM. Joitakin meriturvallisuuden osa-alueita säädellään myös kansallisella tasolla. Hallinnolliset meriturvallisuuden ohjauskeinot sisältävät aluksen rakenteisiin ja varustukseen, alusten kunnon valvontaan, merimiehiin ja merityön tekemiseen sekä navigointiin liittyviä ohjauskeinoja. Taloudellisiin ohjauskeinoihin kuuluvat esimerkiksi väylä- ja satamamaksut, merivakuutukset, P&I klubit, vastuullisuus- ja korvauskysymykset sekä taloudelliset kannustimet. Taloudellisten ohjauskeinojen käyttö meriturvallisuuden edistämiseen on melko vähäistä verrattuna hallinnollisten ohjauskeinojen käyttöön, mutta niitä voitaisiin varmasti käyttää enemmänkin. Ongelmana taloudellisten ohjauskeinojen käytössä on se, että ne kuuluvat pitkälti kansallisen sääntelyn piiriin, joten alueellisten tai kansainvälisten intressien edistäminen taloudellisilla ohjauskeinoilla voi olla hankalaa. Tieto-ohjaus perustuu toimijoiden vapaaehtoisuuteen ja yleisen tiedotuksen lisäksi tieto-ohjaukseen sisältyy esimerkiksi vapaaehtoinen koulutus, sertifiointi tai meriturvallisuuden edistämiseen tähtäävät palkinnot. Poliittisella tasolla meriliikenteen aiheuttamat turvallisuusriskit Suomenlahdella on otettu vakavasti ja paljon työtä tehdään eri tahoilla riskien minimoimiseksi. Uutta sääntelyä on odotettavissa etenkin liittyen meriliikenteen ympäristövaikutuksiin ja meriliikenteen ohjaukseen kuten meriliikenteen sähköisiin seurantajärjestelmiin. Myös inhimilliseen tekijän merkitykseen meriturvallisuuden kehittämisessä on kiinnitetty lisääntyvissä määrin huomiota, mutta inhimilliseen tekijän osalta tehokkaiden ohjauskeinojen kehittäminen näyttää olevan haasteellista. Yleisimmin lääkkeeksi esitetään koulutuksen kehittämistä. Kirjallisuudessa esitettyjen kriteereiden mukaan tehokkaiden ohjauskeinojen tulisi täyttää seuraavat vaatimukset: 1) tarkoituksenmukaisuus – ohjauskeinojen täytyy olla sopivia asetetun tavoitteen saavuttamiseen, 2) taloudellinen tehokkuus – ohjauskeinon hyödyt vs. kustannukset tulisi olla tasapainossa, 3) hyväksyttävyys – ohjauskeinon täytyy olla hyväksyttävä asianosaisten ja myös laajemman yhteiskunnan näkökulmasta katsottuna, 4) toimeenpano – ohjauskeinon toimeenpanon pitää olla mahdollista ja sen noudattamista täytyy pystyä valvomaan, 5) lateraaliset vaikutukset – hyvällä ohjauskeinolla on positiivisia seurannaisvaikutuksia muutoinkin kuin vain ohjauskeinon ensisijaisten tavoitteiden saavuttaminen, 6) kannustin ja uuden luominen – hyvä ohjauskeino kannustaa kokeilemaan uusia ratkaisuja ja kehittämään toimintaa. Meriturvallisuutta koskevaa sääntelyä on paljon ja yleisesti ottaen merionnettomuuksien lukumäärä on ollut laskeva viime vuosikymmenien aikana. Suuri osa sääntelystä on ollut tehokasta ja parantanut turvallisuuden tasoa maailman merillä. Silti merionnettomuuksia ja muita vaarallisia tapahtumia sattuu edelleen. Nykyistä sääntelyjärjestelmää voidaan kritisoida monen asian suhteen. Kansainvälisen sääntelyn aikaansaaminen ei ole helppoa: prosessi on yleensä hidas ja tuloksena voi olla kompromissien kompromissi. Kansainvälinen sääntely on yleensä reaktiivista eli ongelmakohtiin puututaan vasta kun jokin onnettomuus tapahtuu sen sijaan että se olisi proaktiivista ja pyrkisi puuttumaan ongelmakohtiin jo ennen kuin jotain tapahtuu. IMO:n työskentely perustuu kansallisvaltioiden osallistumiseen ja sääntelyn toimeenpano tapahtuu lippuvaltioiden toimesta. Kansallisvaltiot ajavat IMO:ssa pääasiallisesti omia intressejään ja sääntelyn toimeenpanossa on suuria eroja lippuvaltioiden välillä. IMO:n kyvyttömyys puuttua havaittuihin ongelmiin nopeasti ja ottaa sääntelyssä huomioon paikallisia olosuhteita on johtanut siihen, että esimerkiksi Euroopan Unioni on alkanut itse säädellä meriturvallisuutta ja että on olemassa sellaisia alueellisia erityisjärjestelyjä kuin PSSA (particularly sensitive sea area – erityisen herkkä merialue). Merenkulkualalla toimii monenlaisia yrityksiä: toisaalta yrityksiä, jotka pyrkivät toimimaan turvallisesti ja kehittämään turvallisuutta vielä korkeammalle tasolle, ja toisaalta yrityksiä, jotka toimivat niin halvalla kuin mahdollista, eivät välitä turvallisuusseikoista, ja joilla usein on monimutkaiset ja epämääräiset omistusolosuhteet ja joita vahingon sattuessa on vaikea saada vastuuseen. Ongelma on, että kansainvälisellä merenkulkualalla kaikkien yritysten on toimittava samoilla markkinoilla. Vastuuttomien yritysten toiminnan mahdollistavat laivaajat ja muut alan toimijat, jotka suostuvat tekemään yhteistyötä niiden kanssa. Välinpitämätön suhtautuminen turvallisuuteen johtuu osaksi myös merenkulun vanhoillisesta turvallisuuskulttuurista. Verrattaessa meriturvallisuuden sääntelyjärjestelmää kokonaisuutena tehokkaiden ohjauskeinoihin kriteereihin, voidaan todeta, että monien kriteerien osalta nykyistä järjestelmää voidaan pitää tehokkaana ja onnistuneena. Suurimmat ongelmat lienevät sääntelyn toimeenpanossa ja ohjauskeinojen kustannustehokkuudessa. Lippuvaltioiden toimeenpanoon perustuva järjestelmä ei toimi toivotulla tavalla, josta mukavuuslippujen olemassa olo on selvin merkki. Ohjauskeinojen, sekä yksittäisten ohjauskeinojen että vertailtaessa eri ohjauskeinoja keskenään, kustannustehokkuutta on usein vaikea arvioida, minkä seurauksena ohjauskeinojen kustannustehokkuudesta ei ole saatavissa luotettavaa tietoa ja tuloksena voi olla, että ohjauskeino on käytännössä pienen riskin eliminoimista korkealla kustannuksella. Kansainvälisen tason meriturvallisuus- (ja merenkulku-) politiikan menettelytavoiksi on ehdotettu myös muita vaihtoehtoja kuin nykyinen järjestelmä, esimerkiksi monitasoista tai polysentristä hallintojärjestelmää. Monitasoisella hallintojärjestelmällä tarkoitetaan järjestelmää, jossa keskushallinto on hajautettu sekä vertikaalisesti alueellisille tasoille että horisontaalisesti ei-valtiollisille toimijoille. Polysentrinen hallintojärjestelmä menee vielä askeleen pidemmälle. Polysentrinen hallintojärjestelmä on hallintotapa, jonka puitteissa kaikentyyppiset toimijat, sekä yksityiset että julkiset, voivat osallistua hallintoon, siis esimerkiksi hallitukset, edunvalvontajärjestöt, kaupalliset yritykset jne. Kansainvälinen lainsäädäntö määrittelee yleiset tasot, mutta konkreettiset toimenpiteet voidaan päättää paikallisella tasolla eri toimijoiden välisessä yhteistyössä. Tämän tyyppisissä hallintojärjestelmissä merenkulkualan todellinen, kansainvälinen mutta toisaalta paikallinen, toimintaympäristö tulisi otetuksi paremmin huomioon kuin järjestelmässä, joka perustuu kansallisvaltioiden keskenään yhteistyössä tekemään sääntelyyn. Tällainen muutos meriturvallisuuden hallinnassa vaatisi kuitenkin suurta periaatteellista suunnanmuutosta, jollaisen toteutumista ei voi pitää kovin todennäköisenä ainakaan lyhyellä tähtäimellä.
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Tutkimuksen tavoitteena on tuottaa malli globaalin tietoliikenneverkkojen palvelutuotannon toteuttamiseksi metsäteollisuuden yrityksessä. Pääongelmana on selvittää miten tietoliikenneverkkojen palvelutuotanto on toteutettava ottaen huomioon tarvittavat toimijat, kustannustehokkuus ja tiedonhallinta. Ongelmaa lähestyttiin IT- johtamisen, ulkoistamisen, yhteistyöverkostojen, prosessien, yhteisten työkalujen ja standardoinnin näkökulmista. Yrityksen tietoliikenneverkkojen nykytilaa ja tavoitetilaa tutkittiin laadullisella kyselytutkimuksella. Tutkimuksen perusteella päädyttiin malliin, jossa tietoliikenneverkkojen palvelutuotannon laadukkuuteen ja tehokkuuteen vaikuttavat oleellisesti toimijat, yhteiset työkalut, standardointi kaikilla tasoilla ja harkittu ja laskelmoitu ulkoistaminen. Keskeiseen rooliin nousivat standardit prosessit ja niitä tukevat yhteiset työkalut, jotka on toteutettu keskitetysti ja kriittisten osien osalta myös paikallisesti. Prosessien ja työkalujen tulee tukea tiedonhallintaa luonnollisena osana päivittäistä toimintaa. Toimijoiden rajapinnat on oltava yksiselitteisesti määritelty ja toimijoiden välillä on kyettävä kommunikoimaan yhteisillä työkaluilla ja jakamaan tietoa avoimesti.
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The deterioration of surface waters is one of the most important issues in the environmental management of the European Union. Thus, the EU Water Framework Directive 2000/60/EC (WFD) requires “good ecological and chemical status” of surface waters by 2015 allowing only a slight departure from ecological reference conditions characterized by the biological communities typical for the conditions of minimal anthropogenic impact. The WFD requires the determination of ecological reference conditions and the present ecological status of surface waters. To meet this legislative demand, sedimentary diatom assemblages were used in these studies with various methods 1) to assess natural and human activity induced environmental changes, 2) to characterize background conditions 3) to evaluate the present ecological status and 4) to predict the future of the water bodies in the light of palaeolimnological data. As the WFD refers to all surface waters, both coastal and inland sites were included. Two long and two short sediment cores from the Archipelago Sea in the northern Baltic Sea were examined for their siliceous microfossils in order to assess (1) the Holocene palaeoenvironmental history and (2) the recent eutrophication of the area. The diatom record was divided into local diatom assemblage zones (LDAZ, long cores) and diatom assemblage zones (DAZ, short cores). Locally weighted weighted averaging regression and calibration (LWWA) was applied for the quantitative reconstruction of past TN concentrations (short cores). An age model for the long cores was constructed by using independent palaeomagnetic and AMS-14C methods. The short cores were dated using radiometric (210Pb, 226Ra and 137Cs) methods. The long cores date back to the early history of the Archipelago Sea, which was freshwater – no salinity increase referable to the brackish phase of the Yoldia Sea is recognized. The nutrient status of the lacustrine phase was slightly higher in the Archipelago Sea than in the Baltic Proper. Initial brackish-water influence is observed at 8 150 ±80 cal. BP (LDAZ4), but fully brackish conditions were established at 7 700 ±80 cal. BP (LDAZ5). The diatom assemblages indicate increasing salinity, warming climate and possible eutrophic conditions during the lacustrine to brackish-water transition. The decreasing abundance of Pseudosolenia calcar-avis (Schultze) Sundström and the increasing abundance of the ice-cover indicator species Pauliella taeniata (Grunow) Round and Basson indicate decreasing salinity and climatic cooling after ca. 5 000 cal. BP. Signs of eutrophication are visible in the most recent diatom assemblage zones of both short cores. Diatom-inferred total nitrogen (DI-TN) reconstructions partially fail to trace the actual measured total nitrogen concentrations especially from the late 1980s to the mid 1990s. This is most likely due to the dominating diatom species Pauliella taeniata, Thalassiosira levanderi Van Goor and Fragilariopsis cylindrus (Grunow) W. Krieger being more influenced by factors such as the length of the ice-season rather than nutrient concentrations. It is concluded that the diatom assemblages of the study sites are principally governed by climate fluctuations, with a slight influence of eutrophication visible in the most recent sediments. There are indications that global warming, with reduced ice cover, could impact the spring blooming diatom species composition in the Archipelago Sea. In addition, increased sediment accumulation in the early 90s coincides with the short ice-seasons suggesting that warming climate with decreasing ice-cover may increase sedimentation in the study area. The diverse diatom assemblages dominated by benthic species (54 %) in DAZ1 in the Käldö Fjärd core can be taken as background diatom assemblages for the Archipelago Sea. Since then turbidity has increased and the diatom assemblages have been dominated by planktonic diatoms from around the mid 1800s onwards. The reconstructed reference conditions for the total nitrogen concentrations fluctuate around 400 μg l-1. Altogether two short sediment cores and eight short cores for top-bottom analysis were retrieved from Lake Orijärvi and Lake Määrjärvi to assess the impact of the acid mine drainage (AMD) derived metals from the Orijärvi mine tailings on the diatom communities of the lakes. The Cu (Pb, Zn) mine of Orijärvi (1757 – 1956) was the first one in Finland where flotation techniques (1911 – 1955) were used to enrich ore and large quantities of tailings were produced. The AMD derived metal impact to the lakes was found to be among the heaviest thus far recorded in Finland. Concentrations of Cu, Pb and Zn in Lake Orijärvi sediments are two to three orders of magnitude higher than background values. The metal inputs have affected Lake Orijärvi and Lake Määrjärvi diatom communities at the community levels through shifts in dominant taxa (both lakes) and at the individual level through alteration in frustule morphology (Lake Orijärvi). At present, lake water still has elevated heavy metal levels, indicating that the impact from the tailings area continues to affect both lakes. Lake Orijärvi diatom assemblages are completely dominated by benthic species and are lacking planktonic diatoms. In Lake Määrjärvi the proportion of benthic and tychoplanktonic diatoms has increased and the planktonic taxa have decreased in abundance. Achnanthidium minutissimum Kützing and Brachysira vitrea (Grun.) R. Ross in Hartley were the most tolerant species to increased metal concentrations. Planktonic diatoms are more sensitive to metal contamination than benthic taxa, especially species in the genus Cyclotella (Kützing) Brébisson. The ecological reference conditions assessed in this study for Lake Orijärvi and Lake Määrjärvi comprise diverse planktonic and benthic communitites typical of circumneutral oligotrophic lakes, where the planktonic diatoms belonging to genera Cyclotella , Aulacoseira Thwaites, Tabellaria Ehrenberg and Asterionella Hassall dominate in relative abundances up to ca. 70%. The benthic communities are more diverse than the planktonic consisting of diatoms belonging to the genera Achnanthes Bory, Fragilaria Lyngbye and Navicula St. Vincent. This study clearly demonstrates that palaeolimnological methods, especially diatom analysis, provide a powerful tool for the EU Water Frame Work Directive for defining reference conditions, natural variability and current status of surface waters. The top/bottom approach is a very useful tool in larger-scale studies needed for management purposes. This “before and after” type of sediment sampling method can provide a very time and cost effective assessment of ecological reference conditions of surface waters.
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Mining has severe impacts on its surrounding. Particularly in the developing countries it has degraded the environment and signigicantly altered the socio-economical dynamics of the hosts. Especially relocation disrupts people from their homes, livelihoods, cultures and social activities. Mining industry has failed to develop the local host and streghten its governance structures; instead it has further degraded the development of mineral rich third world countries, which are among the world poorest ones. Cash flows derived from mining companies have not benefitted the crass-root level that however, bears most of the detrimental impacts. Especially if the governance structure of the host is weak, the sudden wealth is likely to accelerate disparities, corruption and even fuel wars. Environmental degradation, miscommunication, mistrust and disputes over land use have created conflicts between the communities and a mining company in Obuasi, Ghana; a case study of this thesis. The disputes are deeply rooted and further fuelled by unrealistic expectations and broken promises. The relations with artisanal and illegal miners have been especially troublesome. Illegal activities, mainly encroachment of the land and assets of the mine, such as vandalising tailings pipes have resulted in profits losses, environmental degradation and security hazards. All challenges mentioned above have to be addressed locally with site-specific solutions. It is vital to increase two-way communication, initiate collaboration and build capacity of the stakeholders such as local communities, NGOs and governance authorities. The locals must be engaged to create livelihood opportunities that are designed with and for them. Capacity can also be strengthened through education and skills training, such as women’s literacy programs. In order to diminish the overdependence of locals to the mine, the activities have to be self -sufficient and able to survive without external financial and managerial inputs. Additionally adequate and fair compensation practises and dispute resolution methods that are understood and accepted by all parties have to be agreed on as early as possible.
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The aim of this study was to characterize the cellular mechanisms leading to the beneficial effect of anti-oxidative gene therapy and pro-angiogenic stem cell therapy in acute peripheral ischemia. Post-ischemic events aim to re-establish tissue blood perfusion, to clear cellular debris, and to regenerate lost tissue by differentiation of satellite cells into myoblasts. Although leukocytes have an essential role in clearing cellular debris and promoting angiogenesis, they also contribute to tissue injury through excessive ROS production. First, we investigated the therapeutic properties of extracellular superoxide dismutase (SOD3) gene transfer. SOD3 was shown to reduce oxidative stress, to normalize glucose metabolism, and to enhance cell proliferation in the ischemic muscle. Analysis of the mitogenic Ras-Erk1/2 pathway showed SOD3 mediated induction offering a plausible explanation for enhanced cell proliferation. In addition, SOD3 reduced NF-κB activity by enhancing IκBα expression thus leading to reduced expression of inflammatory cytokines and adhesion molecules with consequent reduction in macrophage infiltration. Secondly, we sought to determine the fate and the effect of locally transplanted mesenchymal stem/stromal cells (MSCs) in acute ischemia. We showed that a vast majority of the transplanted cells are cleared from the injury site within 24 hours after local transplantation. Despite rapid clearance, transplantation was able to temporarily promote angiogenesis and cell proliferation in the muscle. Lack of graft-derived growth factor expression suggests other than secretory function to mediate this observed effect. In conclusion, both SOD3 and MSCs could be utilized to alleviate peripheral ischemia induced tissue injury. We have described a previously unidentified growth regulatory role for SOD3, and suggest a novel mechanism whereby transplanted MSCs enhance the reparative potential of the recipient tissue through physical contacts.
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The oxygen cutting is a thermal cutting process, in which metal is heated locally up to its ignition temperature and burnt off by oxygen blast. Oxygen cutting can be used to remove upset metal of a hollow bar occurred due to solid-state welding process. The main goal of this research was to establish a connection between oxygen blasts and mass of metal removed and relate findings to production to suggest improvements to the current process. This master´s thesis describes the designing and building of a test rig for oxygen blowing measurements. It also contains all executed tests and test results, which were carried out. There are different cutting parameters which were studied as well as their effect on cutting process. The oxygen cutting process, used in solid-state welding process, can be improved by the test results.
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Programming and mathematics are core areas of computer science (CS) and consequently also important parts of CS education. Introductory instruction in these two topics is, however, not without problems. Studies show that CS students find programming difficult to learn and that teaching mathematical topics to CS novices is challenging. One reason for the latter is the disconnection between mathematics and programming found in many CS curricula, which results in students not seeing the relevance of the subject for their studies. In addition, reports indicate that students' mathematical capability and maturity levels are dropping. The challenges faced when teaching mathematics and programming at CS departments can also be traced back to gaps in students' prior education. In Finland the high school curriculum does not include CS as a subject; instead, focus is on learning to use the computer and its applications as tools. Similarly, many of the mathematics courses emphasize application of formulas, while logic, formalisms and proofs, which are important in CS, are avoided. Consequently, high school graduates are not well prepared for studies in CS. Motivated by these challenges, the goal of the present work is to describe new approaches to teaching mathematics and programming aimed at addressing these issues: Structured derivations is a logic-based approach to teaching mathematics, where formalisms and justifications are made explicit. The aim is to help students become better at communicating their reasoning using mathematical language and logical notation at the same time as they become more confident with formalisms. The Python programming language was originally designed with education in mind, and has a simple syntax compared to many other popular languages. The aim of using it in instruction is to address algorithms and their implementation in a way that allows focus to be put on learning algorithmic thinking and programming instead of on learning a complex syntax. Invariant based programming is a diagrammatic approach to developing programs that are correct by construction. The approach is based on elementary propositional and predicate logic, and makes explicit the underlying mathematical foundations of programming. The aim is also to show how mathematics in general, and logic in particular, can be used to create better programs.
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PIXE (Particle Induce X-ray Emission spectrometry) was used for analysing stem bark and stem wood of Scots pine, Norway spruce and Silver birch. Thick samples were irradiated, in laboratory atmosphere, with 3 MeV protons and the beam current was measured indirectly using a photo multiplicator (PM) tube. Both point scans and bulk analyses were performed with the 1 mm diameter proton beam. In bulk analyses, whole bark and sectors of discs of the stem wood were dry ashed at 550 ˚C. The ashes were homogenised by shaking and prepared to target pellets for PIXE analyses. This procedure generated representative samples to be analysed, but the enrichment also enabled quantification of some additional trace elements. The ash contents obtained as a product of the sample preparation procedure also showed to be of great importance in the evaluation of results in environmental studies. Spot scans from the pith of pine wood outwards, showed clearly highest concentrations of manganese, calcium and zinc in the first spot irradiated, or 2-3 times higher than in the surrounding wood. For stem wood from the crown part of a pine this higher concentration level was found in the first four spots/mms, including the pith and the two following growth rings. Zinc showed increasing concentrations outwards in sapwood of the pine stem, with the over-all lowest concentrations in the inner half of the sapwood. This could indicate emigration of this element from sapwood being under transformation to heartwood. Point scans across sapwood of pine and spruce showed more distinct variations in concentrations relative to hearth wood. Higher concentrations of e.g. zinc, calcium and manganese were found in earlywood than in denser latewood. Very high concentrations of iron and copper were also seen for some earlywood increments. The ash content of stem bark is up to and order higher than for the stem wood. However, when the elemental concentration in ashes of bark and wood of the same disc were compared, these are very similar – this when trees are growing at spots with no anthropogenic contamination from the atmosphere. The largest difference was obtained for calcium which appeared at two times high concentrations in ashes of bark than in ashes of the wood (ratio of 2). Pine bark is often used in monitoring of atmospheric pollution, where concentrations in bark samples are compared. Here an alternative approach is suggested: Bark and the underlying stem wood of a pine trees are dry ashed and analysed. The elemental concentration in the bark ash is then compared to the concentration of the same element in the wood ash. Comparing bark to wood includes a normalisation for the varying availability of an element from the soil at different sites. When this comparison is done for the ashes of the materials, a normalisation is also obtained for the general and locally different enrichment of inorganic elements from wood to bark. Already a ratio >2 between the concentration in the bark ash and the concentration in the wood ash could indicate atmospheric pollution. For monitoring where bark is used, this way of “inwards” comparison is suggested - instead of comparing to results from analyses of bark from other trees (read reference areas), growing at sites with different soil and, locally, different climate conditions. This approach also enables evaluation of atmospheric pollution from sampling of only relative few individual trees –preferable during forest felling.