The role of catechol-O-methyltransferase (COMT) and the effects of COMT inhibition in brain and in cardiovascular and renal pathophysiology

Catechol-O-methyltransferase (COMT) metabolizes catecholamines such as dopamine (DA), noradrenaline (NA) and adrenaline, which are vital neurotransmitters and hormones that play important roles in the regulation of physiological processes. COMT enzyme has a functional Val158Met polymorphism in humans, which affects the subjects COMT activity. Increasing evidence suggests that this functional polymorphism may play a role in the etiology of various diseases from schizophrenia to cancers. The aim of this project was to provide novel biochemical information on the physiological and especially pathophysiological roles of COMT enzyme as well as the effects of COMT inhibition in the brain and in the cardiovascular and renal system. To assess the roles of COMT and COMT inhibition in pathophysiology, we used four different study designs. The possible beneficial effects of COMT inhibition were studied in double-transgenic rats (dTGRs) harbouring human angiotensinogen and renin genes. Due to angiotensin II (Ang II) overexpression, these animals exhibit severe hypetension, cardiovascular and renal end-organ damage and mortality of approximately 25-40% at the age of 7-weeks. The dTGRs and their Sprague-Dawley controls tissue samples were assessed with light microscopy, immunohistochemistry, reverse transcriptase-polymerase chain reaction (RT-PCR) and high-pressure liquid chromatography (HPLC) to evaluate the tissue damages and the possible protective effects pharmacological intervention with COMT inhibitors. In a second study, the consequence of genetic and pharmacological COMT blockade in blood pressure regulation during normal and high-sodium was elucidated using COMT-deficient mice. The blood pressure and the heart rate were measured using direct radiotelemetric blood pressure surveillance. In a third study, the effects of acute and subchronic COMT inhibition during combined levodopa (L-DOPA) + dopa decarboxylase inhibitor treatment in homocysteine formation was evaluated. Finally, we assessed the COMT enzyme expression, activity and cellular localization in the CNS during inflammation-induced neurodegeneration using Western blotting, HPLC and various enzymatic assays. The effects of pharmacological COMT inhibition on neurodegeneration were also studied. The COMT inhibitor entacapone protected against the Ang II-induced perivascular inflammation, renal damage and cardiovascular mortality in dTGRs. COMT inhibitors reduced the albuminuria by 85% and prevented the cardiovascular mortality completely. Entacapone treatment was shown to ameliorate oxidative stress and inflammation. Furthermore, we established that the genetic and pharmacological COMT enzyme blockade protects against the blood pressure-elevating effects of high sodium intake in mice. These effects were mediated via enhanced renal dopaminergic tone and suggest an important role of COMT enzyme, especially in salt-sensitive hypertension. Entacapone also ameliorated the L-DOPA-induced hyperhomocysteinemia in rats. This is important, since decreased homocysteine levels may decrease the risk of cardiovascular diseases in Parkinson´s disease (PD) patients using L-DOPA. The Lipopolysaccharide (LPS)-induced inflammation and subsequent delayed dopaminergic neurodegeneration were accompanied by up-regulation of COMT expression and activity in microglial cells as well as in perivascular cells. Interestingly, similar perivascular up-regulation of COMT expression in inflamed renal tissue was previously noted in dTGRs. These results suggest that inflammation reactions may up-regulate COMT expression. Furthermore, this increased glial and perivascular COMT activity in the central nervous system (CNS) may decrease the bioavailability of L-DOPA and be related to the motor fluctuation noted during L-DOPA therapy in PD patients.

Essays on socially optimal phosphorus policies in crop production

Phosphorus is a nutrient needed in crop production. While boosting crop yields it may also accelerate eutrophication in the surface waters receiving the phosphorus runoff. The privately optimal level of phosphorus use is determined by the input and output prices, and the crop response to phosphorus. Socially optimal use also takes into account the impact of phosphorus runoff on water quality. Increased eutrophication decreases the economic value of surface waters by Deteriorating fish stocks, curtailing the potential for recreational activities and by increasing the probabilities of mass algae blooms. In this dissertation, the optimal use of phosphorus is modelled as a dynamic optimization problem. The potentially plant available phosphorus accumulated in soil is treated as a dynamic state variable, the control variable being the annual phosphorus fertilization. For crop response to phosphorus, the state variable is more important than the annual fertilization. The level of this state variable is also a key determinant of the runoff of dissolved, reactive phosphorus. Also the loss of particulate phosphorus due to erosion is considered in the thesis, as well as its mitigation by constructing vegetative buffers. The dynamic model is applied for crop production on clay soils. At the steady state, the analysis focuses on the effects of prices, damage parameterization, discount rate and soil phosphorus carryover capacity on optimal steady state phosphorus use. The economic instruments needed to sustain the social optimum are also analyzed. According to the results the economic incentives should be conditioned on soil phosphorus values directly, rather than on annual phosphorus applications. The results also emphasize the substantial effects the differences in varying discount rates of the farmer and the social planner have on optimal instruments. The thesis analyzes the optimal soil phosphorus paths from its alternative initial levels. It also examines how erosion susceptibility of a parcel affects these optimal paths. The results underline the significance of the prevailing soil phosphorus status on optimal fertilization levels. With very high initial soil phosphorus levels, both the privately and socially optimal phosphorus application levels are close to zero as the state variable is driven towards its steady state. The soil phosphorus processes are slow. Therefore, depleting high phosphorus soils may take decades. The thesis also presents a methodologically interesting phenomenon in problems of maximizing the flow of discounted payoffs. When both the benefits and damages are related to the same state variable, the steady state solution may have an interesting property, under very general conditions: The tail of the payoffs of the privately optimal path as well as the steady state may provide a higher social welfare than the respective tail of the socially optimal path. The result is formalized and an applied to the created framework of optimal phosphorus use.

Integration of natural hazards, risk and climate change into spatial planning practices

Most countries of Europe, as well as many countries in other parts of the world, are experiencing an increased impact of natural hazards. It is often speculated, but not yet proven, that climate change might influence the frequency and magnitude of certain hydro-meteorological natural hazards. What has certainly been observed is a sharp increase in financial losses caused by natural hazards worldwide. Eventhough Europe appears to be a space that is not affected by natural hazards to such catastrophic extents as other parts of the world are, the damages experienced here are certainly increasing too. Natural hazards, climate change and, in particular, risks have therefore recently been put high on the political agenda of the EU. In the search for appropriate instruments for mitigating impacts of natural hazards and climate change, as well as risks, the integration of these factors into spatial planning practices is constantly receiving higher attention. The focus of most approaches lies on single hazards and climate change mitigation strategies. The current paradigm shift of climate change mitigation to adaptation is used as a basis to draw conclusions and recommendations on what concepts could be further incorporated into spatial planning practices. Especially multi-hazard approaches are discussed as an important approach that should be developed further. One focal point is the definition and applicability of the terms natural hazard, vulnerability and risk in spatial planning practices. Especially vulnerability and risk concepts are so many-fold and complicated that their application in spatial planning has to be analysed most carefully. The PhD thesis is based on six published articles that describe the results of European research projects, which have elaborated strategies and tools for integrated communication and assessment practices on natural hazards and climate change impacts. The papers describe approaches on local, regional and European level, both from theoretical and practical perspectives. Based on these, passed, current and future potential spatial planning applications are reviewed and discussed. In conclusion it is recommended to shift from single hazard assessments to multi-hazard approaches, integrating potential climate change impacts. Vulnerability concepts should play a stronger role than present, and adaptation to natural hazards and climate change should be more emphasized in relation to mitigation. It is outlined that the integration of risk concepts in planning is rather complicated and would need very careful assessment to ensure applicability. Future spatial planning practices should also consider to be more interdisciplinary, i.e. to integrate as many stakeholders and experts as possible to ensure the sustainability of investments.

Optimaalinen rangaistus talousrikoksesta : Tutkimus velallisen rikoksista

Optimal Punishment of Economic Crime: A Study on Bankruptcy Crime This thesis researches whether the punishment practise of bankruptcy crimes is optimal in light of Gary S. Becker’s theory of optimal punishment. According to Becker, a punishment is optimal if it eliminates the expected utility of the crime for the offender and - on the other hand - minimizes the cost of the crime to society. The decision process of the offender is observed through their expected utility of the crime. The expected utility is calculated based on the offender's probability of getting caught, the cost of getting caught and the profit from the crime. All objects including the punishment are measured in cash. The cost of crimes to the society is observed defining the disutility caused by the crime to the society. The disutility is calculated based on the cost of crime prevention, crime damages, punishment execution and the probability of getting caught. If the goal is to minimize the crime profits, the punishments of bankruptcy crimes are not optimal. If the debtors would decide whether or not to commit the crime solely based on economical consideration, the crime rate would be multiple times higher than the current rate is. The prospective offender relies heavily on non-economic aspects in their decision. Most probably social pressure and personal commitment to oblige the laws are major factors in the prospective criminal’s decision-making. The function developed by Becker measuring the cost to society was not useful in the measurement of the optimality of a punishment. The premise of the function that the costs of the society correlate to the costs for the offender from the punishment proves to be unrealistic in observation of the bankruptcy crimes. However, it was observed that majority of the cost of crime for the society are caused by the crime damages. This finding supports the preventive criminal politics.

From Francovich to Köbler and beyond : The evolution of a State liability regime for the EC

The aim of this paper is to present the evolution of the Francovich doctrine within the European legal order. The first part deals with the gradual development of the ECJ's case law on State liability in damages for breach of EC law. Starting from the seminal Francovich and Brasserie du Pêcheur, the clarification of the criteria set by the Court is attempted with reference to subsequent case law, whereas issues concerning the extent and form of the compensation owned are also mentioned. The second part concerns one of the more recent developments in the field, namely State liability for breaches of Community law attributed to national judiciary. The Court's ruling in Köbler is examined in connection with two other recent judgments, namely Commission v. Italy of 2003 and Kühne & Heitz, as an attempt of the ECJ to reframe its relationships with national supreme courts and appropriate for itself the position of the Supreme Court in the European legal order. The implications on State liability claims by the ruling in Commission v. France of 1997 constitute the theme of the third part, where it is submitted that Member States can also be held liable for disregard of Community law by private individuals within their respected territories. To this extent, Schmidberger is viewed as a manifestation of this opinion, with fundamental rights acquiring a new dimension, being invoked by the States, contra the individuals as a shield to liability claims. Finally, the third part examines the relationship between the Francovich doctrine and the principle of legal certainty and concludes that the solutions employed by the ECJ have been both predictable and acceptable by the national legal orders. Keywords: State liability, damages, Francovich, Köbler, Schmidberger

Endoplasmic reticulum stress and cell death mechanisms in the cell model of Huntington’s disease

This thesis clarifies important molecular pathways that are activated during the cell death observed in Huntington’s disease. Huntington’s disease is one of the most common inherited neurodegenerative diseases, which is primarily inherited in an autosomal dominant manner. HD is caused by an expansion of CAG repeats in the first exon of the IT15 gene. IT15 encodes the production of a Huntington’s disease protein huntingtin. Mutation of the IT15 gene results in a long stretch of polyQ residues close to the amino-terminal region of huntingtin. Huntington’s disease is a fatal autosomal neurodegenerative disorder. Despite the current knowledge of HD, the precise mechanism behind the selective neuronal death, and how the disease propagates, still remains an enigma. The studies mainly focused on the control of endoplasmic reticulum (ER) stress triggered by the mutant huntingtin proteins. The ER is a delicate organelle having essential roles in protein folding and calcium regulation. Even the slightest perturbations on ER homeostasis are effective enough to trigger ER stress and its adaptation pathways, called unfolded protein response (UPR). UPR is essential for cellular homeostasis and it adapts ER to the changing environment and decreases ER stress. If adaptation processes fail and stress is excessive and prolonged; irreversible cell death pathways are engaged. The results showed that inhibition of ER stress with chemical agents are able to decrease cell death and formation of toxic cell aggregates caused by mutant huntingtin proteins. The study concentrated also to the NF-κB (nuclear factor-kappaB) pathway, which is activated during ER stress. NF-κB pathway is capable to regulate the levels of important cellular antioxidants. Cellular antioxidants provide a first line of defence against excess reactive oxygen species. Excess accumulation of reactive oxygen species and subsequent activation of oxidative stress damages motley of vital cellular processes and induce cell degeneration. Data showed that mutant huntingtin proteins downregulate the expression levels of NF-κB and vital antioxidants, which was followed by increased oxidative stress and cell death. Treatment with antioxidants and inhibition of oxidative stress were able to counteract these adverse effects. In addition, thesis connects ER stress caused by mutant huntingtin to the cytoprotective autophagy. Autophagy sustains cellular balance by degrading potentially toxic cell proteins and components observed in Huntington’s disease. The results revealed that cytoprotective autophagy is active at the early points (24h) of ER stress after expression of mutant huntingtin proteins. GADD34 (growth arrest and DNA damage-inducible gene 34), which is previously connected to the regulation of translation during cell stress, was shown to control the stimulation of autophagy. However, GADD34 and autophagy were downregulated at later time points (48h) during mutant huntingtin proteins induced ER stress, and subsequently cell survival decreased. Overexpression GADD34 enhanced autophagy and decreased cell death, indicating that GADD34 plays a critical role in cell protection. The thesis reveales new interesting data about the neuronal cell death pathways seen in Huntington’s disease, and how cell degeneration is partly counteracted by various therapeutic agents. Expression of mutant huntingtin proteins is shown to alter signaling events that control ER stress, oxidative stress and autophagy. Despite that Huntington’s disease is mainly an untreatable disorder; these findings offer potential targets and neuroprotective strategies in designing novel therapies for Huntington’s disease.

Kohdennetut liposomit syövän hoidossa

Suurin ongelma syöpätautien lääkehoidossa on sen aiheuttamat toksiset sivuvaikutukset. Tyypillisesti vain noin 1 % elimistöön annostellusta lääkeaineesta saavuttaa hoitoa tarvitsevat syöpäsolut, loppuosa lääkeaineesta jää vahingoittamaan elimistön terveitä soluja. Toksiset sivuvaikutukset rajoittavat lääkehoidon annoksen nostamista elimistössä riittävälle pitoisuudelle, mikä johtaa usein sairauden ennenaikaiseen pahenemiseen ja mahdollisen lääkeaineresistenssin kehittymiseen. Liposomien välittämä lääkeaineen kohdentaminen voidaan jakaa kahteen eri menetelmään: passiiviseen ja aktiiviseen kohdentamiseen. Liposomien passiivisen kohdentamisen tarkoituksena on lisätä sytotoksisen lääkeaineen paikallistumista pelkästään kasvainkudokseen. Passiivinen kohdentaminen perustuu liposomien kulkeutumiseen verenkierron mukana, jolloin liposomit kerääntyvät epänormaalisti muodostuneeseen kasvainkudokseen. Liposomien aktiivisella kohdentamisella pyritään parantamaan passiivisesti kohdentuvien liposomien terapeuttista tehokkuutta kohdentamalla lääkeaineen vaikutus pelkästään syöpäsoluihin. Aktiivisessa kohdennuksessa liposomin pintaan kiinnitetään ligandi, joka spesifisesti tunnistaa kohdesolun. Tämän pro gradu -tutkielman kirjallisen osion tarkoituksena oli tutustua syöpäkudokseen kohdennettujen liposomien ominaisuuksiin tehokkaan soluunoton ja sytotoksisuuden saavuttamiseksi. Kokeellisessa osiossa tutkittiin kohdennettujen liposomien soluunottoa ja sytotoksista vaikutusta ihmisen munasarjasta eristetyillä adenokarsinoomasoluilla (SKOV-3). Liposomit kohdennettiin setuksimabi (C225, Erbitux®) vasta-aineella, jonka on todettu olevan tietyissä syöpätyypeissä (mm. keuhko- ja kolorektaalisyövissä, pään ja kaulan syövissä sekä rinta-, munuais-, eturauhas-, haima- ja munasarjasyövissä) yli-ilmentyneen epidermaalisen kasvutekijäreseptoriperheen HER1-proteiinin (ErbB-1, EGFR, epidermal growth factor receptor) spesifinen ja selektiivinen inhibiittori. Afrikan viherapinan munuaisista lähtöisin olevaa CV-1 solulinjaa käytettiin kontrollina kuvaamaan elimistön normaaleja soluja. Kohdennettujen liposomien soluunottoa tutkittiin soluunottokokeilla, joissa käytettiin kontrollina kohdentamattomia pegyloituja liposomeja. Setuksimabi-vasta-aineen spesifinen sitoutuminen EGF-reseptoriin todettiin kilpailutuskokeilla. Doksorubisiinia sisältävien immunoliposomien sytotoksisuutta selvitettiin Alamar Blue™ -elävyystestillä. Lisäksi immunoliposomien säilyvyyttä seurattiin mittaamalla liposomien keskimääräinen halkaisija noin kahden viikon välein. Setuksimabi-vasta-aineella kohdennettujen liposomien soluunotto oli huomattavasti suurentunut SKOV-3 syöpäsoluissa ja doksorubisiinia sisältävät kohdennetut liposomit aiheuttivat voimakkaamman sytotoksisen vaikutuksen kuin kohdentamattomat liposomit. Kohdennettujen doksorubisiiniliposomien sytotoksisuus tuli kuitenkin esille viiveellä, mikä viittaa lääkeaineen hitaaseen vapautumiseen liposomista. Suurentunutta soluunottoa ja sytotoksista vaikutusta ei havaittu CV-1 solulinjassa. Kohdennettujen liposomien sovellusmahdollisuudet lääketieteessä ja syövän hoidossa ovat merkittävät. Tällä hetkellä liposomien kliininen käyttö rajoittuu passiivisesti kohdennettuihin liposomeihin (Doxil® (Am.),Caelyx® (Eur.)). Lupaavista solukokeista huolimatta kohdennettujen liposomien terapeuttinen käyttö tulevaisuudessa näyttää haasteelliselta.

Männyn neulaskadon arviointi laserkeilauksella

Leaf and needle biomasses are key factors in forest health. Insects that feed on needles cause growth losses and tree mortality. Insect outbreaks in Finnish forests have increased rapidly during the last decade and due to climate change the damages are expected to become more serious. There is a need for cost-efficient methods for inventorying these outbreaks. Remote sensing is a promising means for estimating forests and damages. The purpose of this study is to investigate the usability of airborne laser scanning in estimating Scots pine defoliation caused by the common pine sawfly (Diprion pini L.). The study area is situated in Ilomantsi district, eastern Finland. Study materials included high-pulse airborne laser scannings from July and October 2008. Reference data consisted of 90 circular field plots measured in May-June 2009. Defoliation percentage on these field plots was estimated visually. The study was made on plot-level and methods used were linear regression, unsupervised classification, Maximum likelihood method, and stepwise linear regression. Field plots were divided in defoliation classes in two different ways: When divided in two classes the defoliation percentages used were 0–20 % and 20–100 % and when divided in four classes 0–10 %, 10–20 %, 20–30 % and 30–100 %. The results varied depending on method and laser scanning. In the first laser scanning the best results were obtained with stepwise linear regression. The kappa value was 0,47 when using two classes and 0,37 when divided in four classes. In the second laser scanning the best results were obtained with Maximum likelihood. The kappa values were 0,42 and 0,37, correspondingly. The feature that explained defoliation best was vegetation index (pulses reflected from height > 2m / all pulses). There was no significant difference in the results between the two laser scannings so the seasonal change in defoliation could not be detected in this study.

Irradiation effects in graphene and related materials

Nanomaterials with a hexagonally ordered atomic structure, e.g., graphene, carbon and boron nitride nanotubes, and white graphene (a monolayer of hexagonal boron nitride) possess many impressive properties. For example, the mechanical stiffness and strength of these materials are unprecedented. Also, the extraordinary electronic properties of graphene and carbon nanotubes suggest that these materials may serve as building blocks of next generation electronics. However, the properties of pristine materials are not always what is needed in applications, but careful manipulation of their atomic structure, e.g., via particle irradiation can be used to tailor the properties. On the other hand, inadvertently introduced defects can deteriorate the useful properties of these materials in radiation hostile environments, such as outer space. In this thesis, defect production via energetic particle bombardment in the aforementioned materials is investigated. The effects of ion irradiation on multi-walled carbon and boron nitride nanotubes are studied experimentally by first conducting controlled irradiation treatments of the samples using an ion accelerator and subsequently characterizing the induced changes by transmission electron microscopy and Raman spectroscopy. The usefulness of the characterization methods is critically evaluated and a damage grading scale is proposed, based on transmission electron microscopy images. Theoretical predictions are made on defect production in graphene and white graphene under particle bombardment. A stochastic model based on first-principles molecular dynamics simulations is used together with electron irradiation experiments for understanding the formation of peculiar triangular defect structures in white graphene. An extensive set of classical molecular dynamics simulations is conducted, in order to study defect production under ion irradiation in graphene and white graphene. In the experimental studies the response of carbon and boron nitride multi-walled nanotubes to irradiation with a wide range of ion types, energies and fluences is explored. The stabilities of these structures under ion irradiation are investigated, as well as the issue of how the mechanism of energy transfer affects the irradiation-induced damage. An irradiation fluence of 5.5x10^15 ions/cm^2 with 40 keV Ar+ ions is established to be sufficient to amorphize a multi-walled nanotube. In the case of 350 keV He+ ion irradiation, where most of the energy transfer happens through inelastic collisions between the ion and the target electrons, an irradiation fluence of 1.4x10^17 ions/cm^2 heavily damages carbon nanotubes, whereas a larger irradiation fluence of 1.2x10^18 ions/cm^2 leaves a boron nitride nanotube in much better condition, indicating that carbon nanotubes might be more susceptible to damage via electronic excitations than their boron nitride counterparts. An elevated temperature was discovered to considerably reduce the accumulated damage created by energetic ions in both carbon and boron nitride nanotubes, attributed to enhanced defect mobility and efficient recombination at high temperatures. Additionally, cobalt nanorods encapsulated inside multi-walled carbon nanotubes were observed to transform into spherical nanoparticles after ion irradiation at an elevated temperature, which can be explained by the inverse Ostwald ripening effect. The simulation studies on ion irradiation of the hexagonal monolayers yielded quantitative estimates on types and abundances of defects produced within a large range of irradiation parameters. He, Ne, Ar, Kr, Xe, and Ga ions were considered in the simulations with kinetic energies ranging from 35 eV to 10 MeV, and the role of the angle of incidence of the ions was studied in detail. A stochastic model was developed for utilizing the large amount of data produced by the molecular dynamics simulations. It was discovered that a high degree of selectivity over the types and abundances of defects can be achieved by carefully selecting the irradiation parameters, which can be of great use when precise pattering of graphene or white graphene using focused ion beams is planned.

After interpretation.

Using 58 audio recorded sessions of psychoanalysis (coming from two analysts and three patients) as data and conversation analysis as method, this paper shows how psychoanalysts deal with patients’ responses to interpretations. After the analyst offers an interpretation, the patient responds: at that point (in the “third position”), the analysts recurrently modify the tenor of the description from what it was in the patients’ responses. They intensify the emotional valence of the description, or they reveal layers of the patients’ experience other than those that the patient reported. Both are usually accomplished in an implicit, non-marked way, and they discreetly index possible opportunities for the patients to modify their understandings of the initial interpretation. Although the patients usually do not fully endorse these modifications, the data available suggests that during the sessions that follow, the participants do work with the aspects of patients’ experience that the analyst highlighted. In discussion, it is suggested that actions that the psychoanalysts produce in therapy, such as choices of turn design in third position, may be informed by working understanding of the minds and mental conflicts of individual patients, alongside the more general therapeutic model of mind they hold to.

Change detection and controlling forest information using multi-temporal Landsat TM imagery.

A method was developed for relative radiometric calibration of single multitemporal Landsat TM image, several multitemporal images covering each others, and several multitemporal images covering different geographic locations. The radiometricly calibrated difference images were used for detecting rapid changes on forest stands. The nonparametric Kernel method was applied for change detection. The accuracy of the change detection was estimated by inspecting the image analysis results in field. The change classification was applied for controlling the quality of the continuously updated forest stand information. The aim was to ensure that all the manmade changes and any forest damages were correctly updated including the attribute and stand delineation information. The image analysis results were compared with the registered treatments and the stand information base. The stands with discrepancies between these two information sources were recommended to be field inspected.

Lumettoman maan routaolojen mallintaminen ja ennustettavuus muuttuvassa ilmastossa

Raportissa on arvioitu ilmastonmuutoksen vaikutusta Suomen maaperän talviaikaiseen jäätymiseen lämpösummien perusteella. Laskelmat kuvaavat roudan paksuutta nimenomaisesti lumettomilla alueilla, esimerkiksi teillä, joilta satanut lumi aurataan pois. Luonnossa lämpöä eristävän lumipeitteen alla routaa on ohuemmin kuin tällaisilla lumettomilla alueilla. Toisaalta luonnollisessa ympäristössä paikalliset erot korostuvat johtuen mm. maalajeista ja kasvillisuudesta. Roudan paksuudet laskettiin ensin perusjakson 1971–2000 ilmasto-oloissa talviaikaisten säähavaintotietoihin pohjautuvien lämpötilojen perusteella. Sen jälkeen laskelmat toistettiin kolmelle tulevalle ajanjaksolle (2010–2039, 2040–2069 ja 2070–2099) kohottamalla lämpötiloja ilmastonmuutosmallien ennustamalla tavalla. Laskelman pohjana käytettiin 19 ilmastomallin A1B-skenaarioajojen keskimäärin simuloimaa lämpötilan muutosta. Tulosten herkkyyden arvioimiseksi joitakin laskelmia tehtiin myös tätä selvästi heikompaa ja voimakkaampaa lämpenemisarviota käyttäen. A1B-skenaarion mukaisen lämpötilan nousun toteutuessa nykyisiä mallituloksia vastaavasti routakerros ohenee sadan vuoden aikana Pohjois-Suomessa 30–40 %, suuressa osassa maan keski- ja eteläosissa 50–70 %. Jo lähivuosikymmeninä roudan ennustetaan ohentuvan 10–30 %, saaristossa enemmän. Mikäli lämpeneminen toteutuisi voimakkaimman tarkastellun vaihtoehdon mukaisesti, roudan syvyys pienenisi tätäkin enemmän. Roudan paksuuden vuosienvälistä vaihtelua ja sen muuttumista tulevaisuudessa pyrittiin myös arvioimaan. Leutoina talvina routa ohenee enemmän kuin normaaleina tai ankarina pakkastalvina. Päivittäistä sään vaihtelua simuloineen säägeneraattorin tuottamassa aineistoissa esiintyi kuitenkin liian vähän hyvin alhaisia ja hyvin korkeita lämpötiloja. Siksi näitten lämpötilatietojen pohjalta laskettu roudan paksuuskin ilmeisesti vaihtelee liian vähän vuodesta toiseen. Kelirikkotilanteita voi esiintyä myös kesken routakauden, jos useamman päivän suojasää ja samanaikainen runsas vesisade pääsevät sulattamaan maata. Tällaiset routakauden aikana sattuvat säätilat näyttävätkin yleistyvän lähivuosikymmeninä. Vuosisadan loppua kohti ne sen sijaan maan eteläosissa jälleen vähenevät, koska routakausi lyhenee oleellisesti. Tulevia vuosikymmeniä koskevien ilmastonmuutosennusteiden ohella routaa ja kelirikon esiintymistä on periaatteessa mahdollista ennustaa myös lähiaikojen sääennusteita hyödyntäen. Pitkät, viikkojen tai kuukausien mittaiset sääennusteet eivät tosin ole ainakaan vielä erityisen luotettavia, mutta myös lyhyemmistä ennusteista voisi olla hyötyä mm. tienpitoa suunniteltaessa.

Maidontuottajatila ja ravinnepolitiikka: Tilan toimintamekanismit, politiikan tarve ja ohjauskeinojen vaikuttavuus

Tutkielman tarkoituksena on rakentaa malli, jolla voidaan arvioida maitotilan toimintaa monipuolisesti ravinnehuuhtouman kannalta. Tavoitteena on ennen muuta analyyttinen tarkastelu siten, että kuitenkin huomioiden maidontuotannon ominaispiirteet, keskeisinä esimerkkeinä ravinnon, maidontuotannon ja lannan ominaisuuksien väliset riippuvuudet. Analyysissa tarkastellaan tilanomistajan yksityisen hyödynmaksimoinnin ja yhteiskunnan tavoitteiden eroavaisuutta. Lisäksi johdetaan optimaaliset ohjauskeinot ja arvioidaan eräiden yksinkertaisten ohjauskeinojen vaikuttavuutta. Mallin analysoinnin perusteella yksityinen ja yhteiskunnallinen optimiratkaisu eroavat toisistaan kaikkien päätösmuuttujien osalta. Ei voida kuitenkaan yleispätevästi sanoa muutosten merkittävyyttä tai suuntaa ottamatta kantaa mallin funktiomuotoihin ja parametriarvoihin. Optimaaliset ohjauskeinot tulisi asettaa keinolannoitteen ja lannan levitykselle, väkirehuruokinnalle ja säilörehun viljelylle, mutta ei eläinten määrälle. Toisaalta optimaaliset ohjauskeinot ovat hyvin monimutkaisia. Tarkasteltujen yksinkertaisempien ohjauskeinojen vaikuttavuutta ei voida tarkasti arvioida analyyttisella tasolla. Numeeristen tulosten perusteella yhteiskunnallisessa optimissa eläinmäärä olisi hieman yksityistä optimia pienempi, väkirehun käyttö vähäisempää, enemmän peltoa allokoitaisiin säilörehun viljelyyn ja lannoitustasot olisivat kautta linjan hieman pienemmät. Lannanlevitykset eroavat etäisyyden suhteen: molemmissa tapauksissa lannanlevityksen intensiteetti kasvaa kohti tilan keskusta kuljettaessa, mutta yksityisessä optimissa lähimmälle pellolle dumpataan kaikki ylimääräinen lanta, kun taas yhteiskunnallisessa optimissa lanta levitetään tasaisemmin eri pelloille. Ero kokonaishyvinvoinnissa jää pieneksi, mutta eläinmäärän kasvu kärjistäisi lannan dumppauksen aiheuttamia huuhtoumahaittoja. Yksinkertaisista ohjauskeinoista lannoitusrajoitus sekä ravinne- ja keinolannoitevero osoittautuivat kohtalaisen käyttökelpoisiksi numeeristen tulosten perusteella. Sen sijaan eläinmäärän rajoittaminen ja lannan kuljetuskustannuksia kompensoivat tuet vaikuttavat tulosten perusteella huonoilta ratkaisuilta.