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  • Alvesalo, Joni (Helsingin yliopisto, 2007)
    Chlamydia pneumoniae is a common obligate intracellular bacterium that causes upper and lower respiratory infections worldwide. C. pneumoniae infections are persistence by nature, and an acute infection sometimes turn into chronic. The treatment of acute infections can be problematic. High doses and prolonged treatment with currently used antibiotics are often needed in order to achieve a clinical cure. In addition, more serious diseases such as atherosclerosis have recently been associated with chronic C. pneumoniae infection, which has proven to be extremely difficult to diagnose and impossible to treat with current antibiotics. In the present study, new antichlamydial compounds were searched among synthetic, natural and natural-derived compounds. A library of structurally diverse natural compounds, which were known to have a variety of health promoting effect in humans, was tested against C. pneumoniae. A library of synthetic compounds was pre screened in silico, in order to create smaller and more active targeted library, which was tested against C. pneumoniae. Antichlamydial compounds were found from both libraries, nature based compounds showing higher activity. A new high-throughput screening (HTS) assay was developed in order to search antichlamydial compound more efficiently. After optimizations of this partly automated time-resolved fluorometric immunoassay (TR-FIA) we were able to obtain results that were reliable, reproducible and consistent with mostly used assays in chlamydia susceptibility testing. Host cell response to acute C. pneumoniae infection was monitored in a gene and protein level. We were able to find four different human proteins with a significant difference in their expression, caused by the C. pneumoniae infection. All of these identified proteins were structural proteins, which supports earlier observations about the structural rearrangement that are requirement for a successful infection. In the genome level we were able to identify hundreds of genes that were significantly affected by the infection. In order to get more information out of the microarray data we used gene ontology (GO) classification, which group genes according to biological processes, cellular components and molecular functions. One set of potential drug target genes, was selected using GO classification data and another set of was selected using gene-wise analysis data, where data from the infected cells is compared against the control cell data. Expression changes of all target genes were confirmed with q-PCR, validated genes were silenced with the corresponding small interfering RNA (siRNA) molecule and the effect of silencing to C. pneumoniae infection was monitored. The greatest reduction in the number of C. pneumoniae inclusions was due to the silencing of the gene coding for the transcription factor EGR1, which decreased the number of inclusions by 38.6 %. Both data analysis methods revealed genes whose silencing reduced the number of C. pneumoniae particles more than 25 %, but GO-classified data proved to be more accurate and much more informative, compared to gene-wise analysis data.
  • Launiainen, Terhi (Helsingin yliopisto, 2011)
    Use of adverse drug combinations, abuse of medicinal drugs and substance abuse are considerable social problems that are difficult to study. Prescription database studies might fail to incorporate factors like use of over-the-counter drugs and patient compliance, and spontaneous reporting databases suffer from underreporting. Substance abuse and smoking studies might be impeded by poor participation activity and reliability. The Forensic Toxicology Unit at the University of Helsinki is the only laboratory in Finland that performs forensic toxicology related to cause-of-death investigations comprising the analysis of over 6000 medico-legal cases yearly. The analysis repertoire covers most commonly used drugs and drugs of abuse, and the ensuing database contains also background information and information extracted from the final death certificate. In this thesis, the data stored in this comprehensive post-mortem toxicology database was combined with additional metabolite and genotype analyses that were performed to complete the profile of selected cases. The incidence of drug combinations possessing serious adverse drug interactions was generally low (0.71%), but it was notable for the two individually studied drugs, a common anticoagulant warfarin (33%) and a new generation antidepressant venlafaxine (46%). Serotonin toxicity and adverse cardiovascular effects were the most prominent possible adverse outcomes. However, the specific role of the suspected adverse drug combinations was rarely recognized in the death certificates. The frequency of bleeds was observed to be elevated when paracetamol and warfarin were used concomitantly. Pharmacogenetic factors did not play a major role in fatalities related to venlafaxine, but the presence of interacting drugs was more common in cases showing high venlafaxine concentrations. Nicotine findings in deceased young adults were roughly three times more prevalent than the smoking frequency estimation of living population. Contrary to previous studies, no difference in the proportion of suicides was observed between nicotine users and non-nicotine users. However, findings of abused substances, including abused prescription drugs, were more common in the nicotine users group than in the non-nicotine users group. The results of the thesis are important for forensic and clinical medicine, as well as for public health. The possibility of drug interactions and pharmacogenetic issues should be taken into account in cause-of-death investigations, especially in unclear cases, medical malpractice suspicions and cases where toxicological findings are scarce. Post-mortem toxicological epidemiology is a new field of research that can help to reveal problems in drug use and prescription practises.
  • Panhelainen, Anne (Helsingin yliopisto, 2012)
    Drug addiction is defined as a chronically relapsing disorder of the brain. The characteristic compulsive drug use behaviour despite the negative consequences has been explained by a maladaptive learning phenomenon. Synaptic plasticity, i.e. the ability of neuronal connections to change on demand, forms the basis for learning and memory storage in the brain. Interestingly, many drugs of abuse have been shown to converge in their actions on the mesolimbic dopamine (DA) pathway as they induce synaptic plasticity in the DA neurons of the ventral tegmental area (VTA) that also mediate the recognition of natural rewards and reward-driven learning. This drug-induced plasticity is thought to facilitate future use of the drug i.e. reinforce drug-seeking behavior. Benzodiazepines are anxiolytic and sedative drugs that unfortunately can be addictive in a subset of users. The role of the DA system in benzodiazepine addiction is still controversial and thus this thesis was aimed at studying possible synaptic alterations in the VTA DA neurons induced by acute administration of benzodiazepine ligands. Diazepam and zolpidem were shown to induce persistent plasticity at the glutamatergic synapses in VTA DA neurons; a phenomenon claimed to be a common feature of different kinds of drugs of abuse. The possible effects of this synaptic plasticity at the behavioral level were examined by challenging the locomotor activity of mice with morphine and amphetamine, as the DA system plays a central role in their actions. We found that indeed the locomotor reactions of mice were altered: morphine-induced hyperlocomotion and amphetamine-induced sensitization were attenuated in mice while there was diazepam-induced plasticity at VTA DA neurons (24-72 h after diazepam administration). These findings indicated that the effects of morphine and amphetamine on DA neuron activity might be blunted during diazepam-induced synaptic plasticity. Orexins are neuropeptides synthesized in the hypothalamus; they posses important roles in several behaviors such as the regulation of sleep-wake cycle, arousal, energy balance, stress, motivation and reward. In particular, orexinergic signaling in VTA has been postulated to be important for drug-induced plasticity. The effects of diazepam on the activity of this neuronal population were studied by c-Fos immunohistochemistry as the levels of c-Fos are believed to mirror the activity of neurons. An anxiolytic dose of diazepam prevented the stress-induced increment in the orexinergic activity whereas a clearly sedative dose reduced the activity of these neurons even from the basal levels. These findings led to the formation of the hypothesis that orexinergic activity in the brain could have a role in the anxiolytic, sedative and hypnotic actions of benzodiazepines. In conclusion, this project revealed new aspects about the brain areas and the mechanisms mediating both the therapeutic properties as well as the addictive features of benzodiazepines. New evidence was found for a role of the mesolimbic DA system in mediating the addictive potential of benzodiazepines and a novel hypothesis was devised about how the orexinegic system may play a role in the therapeutic actions of benzodiazepines.
  • Salasuo, Mikko (2004)
    The long development trends in drug use in Finland are often described by means of a 'wave' metaphor. Usually two drug waves are mentioned, the first wave being the more general experimentation with and use of drugs, especially cannabis, in the 1960s. The second wave was an increasingly more common experimentation and use that can be traced to the beginning of the 1990s. The result of the latest increase was a higher use of drugs than ever before. Typical of both of these drug waves was a tie up to international youth culture trends (the hippie movement and the techno and rave culture respectively), whilst both drug waves are also characterised by occasional drugs use and the central position of the user culture. In the study, the cultural appearance of the two drug waves in Finland is viewed from different standpoints within qualitative research, as found in a summary article and in seven other articles. Thematically, the study starts with the cannabis pattern of the 1960s and 1970s, when youth culture was linked to drug use for the first time. The first article to be reviewed analyses these patterns, and will serve as a historical background and thematic standard of comparison for the other articles to be reviewed, which will analyse drug use as linked to the new party culture of the 1990s. The analysis starts with the history of ecstasy—the symbol of the drug phenomena of the 1990s—and how it intersected with the international youth culture. In relation to the spread of ecstasy, the parallel development of the drug markets is surveyed, as well as the difficulties faced when combating these markets. Following this, the "slower" history of the drug phenomenon is analysed through sociological analyses, with the focus on what forms the drug culture has taken in Finland, how users stood out from the rest of the youth culture and what kind of health issues were connected with drug use. Finally, current forms of drug education are studied. The Study Material Several different kinds of study material were used, and were seen to function at different levels, and it was possible to create interesting perspectives on the drug culture by linking these materials together. Among the most important materials to be used were the user interviews, interviews with the authorities, official control data, materials collected from the Internet, and a targeted Internet questionnaire. In particular, the interview material gives information that can be of use when analysing the cultural context of drug use. The remaining materials also contain cultural elements that support the interview material and raise new viewpoints that differ from it. The Study Results Drug waves are connected to certain periods and generations that attach special importance to the use of drugs and the meanings given to it. Both drug use and the users are mobilized as part of a historical and cultural experience that certain generations share. A common world of experience gives rise to different kinds of social and cultural movements, within which people organize themselves in order to pursue and promote a way of life and goals that they find fulfilling. The common world of experience shapes tastes, preferences and behaviour, and thus influences the prevalence of experimentation with drugs and drug use and the meanings attached to them. In practice, this has resulted in new ways of using drugs and new drugs, the emergence of new markets and a new kind of criminality, the development of new drug concepts, and thus the development of new drug patterns. The informal social control of the new cultures of drug use—as well as their rituals and norms—contribute to determining and regulating drug use.
  • Ahtola, Martti (2015)
    The goal of the thesis was to optimize a dry powder layering process that would produce a swelling polymer layer that could work as a base layer for another layer. The GPCG 1 (Glatt) fluidized bed granulator was equipped with a rotor. Such hydrophilic polymers were used for coating that would not be sensible timewise for wet coating methods because of long process time. For design of experiments Definitive Screening was chosen because it works in situations where time is limited and there is high number of parameters. There were six parameters, four related to the equipment settings and two related to the formulation, that were tested on three levels. The results were used to get optimized parameters using a model in MODDE software. The quality of the coating was analyzed by measuring the friability (strain test with fluidized bed granulator), particle size (dynamic image analyzer), density (helium pycnometer and mercurity porosimeter), erosion (size exclusion chromatography), loss on drying (halogen moisture analyzer) and coating efficiency (weighing and loss on drying). Coating was also analyzed also with scanning electron microscopy. The process was robust with regards to sphericity of the coated pellets. In SEM pictures none of the coatings showed complete film formation. Friability method did not show significant differences between batches. Coating efficiency was high for all batches. Correlations between product characteristics were analyzed and some correlations were observed between including correlations between LOD/CE and densities. No correlation between the densities measured with two different methods were seen. Some of the settings in the DOE were too extreme and produced batches that were very difficult to analyze. Two more batches were produced with adjusted settings. This affected somewhat the ability to develop a reliable model. Model development were also affected by insufficient results from erosion tests and because coating efficiency results with water was used. Some stability problems were noticed during design of experiments and chosen equipment limited the scale of settings. Coating material adhered to the surface of the pellets and process could be adjusted by changing the parameters of the DOE. Some correlations were noticed between formulation, equipment settings and coating properties.
  • Frände, Joakim (Suomalainen lakimiesyhdistys, 2013)
    Dual residence in the taxation of individuals Each country has the right to determine on which grounds and to what extent it exercises its tax authority. In the case of individuals a country usually bases its right to levy taxes on the connection between the country and the individual, or the country and the income or wealth in question. This thesis deals with the connection that exists between the country and the individual. Under domestic tax law systems a separation is usually made into full and limited tax liability. Full tax liability arises when there are strong ties between the individual and the state. Residence is usually considered a strong tie that results in full tax liability. A person who is resident in a country, and therefore subject to full tax liability, is usually taxed on his world wide income. However, if the person is not resident, the state does not claim the right to tax the individual as such, but taxes income that arises within the territory of the country. When determining residence in one country, no consideration is given to whether the person is also resident in other countries. Consequently, individuals can as a result of cross border movement be considered resident both in the country of arrival and the country of departure. When two countries both consider an individual resident, dual residence arises. The purpose of this thesis is to analyse three aspects of dual residence. First and foremost, national rules on residence will be analysed, as well as how dual residence occurs in practice. Secondly, the rules on how to determine tax residence for tax treaty purposes are discussed. Thirdly, the tax consequences of dual residence will be investigated. The emphasis will be on the first two aspects of dual residence mentioned. The thesis is based on a dogmatic approach to legal research. Some elements of comparative methods of research are also present. A person who is resident in Finland is subject to full tax liability in Finland. Residence for income tax purposes is determined in the income tax act (ITA) § 11. According to ITA § 11 a person is resident in Finland if he has his main abode and home in Finland, stays over six months in Finland or falls under the three-year rule. Finnish nationals who leave Finland are as a result of the three-year rule considered resident the year of departure and the three following years. Limited tax liability can arise before the three- year period ends if the individual can produce evidence that he lacks substantial ties to Finland. The Finnish rules on residence are partly problematic. The rules on when a visit to Finland has fulfilled the six months requirement are unclear. Also, the three-year rule does not specify what a substantial tie is. The three-year rule furthermore distinguishes between Finnish nationals and foreign nationals. Different tax consequences depending on nationality can be problematic from an EU perspective. A short analysis of the current ECJ cases, however, indicates that the three-year rule is probably in conformity with EU law. Residence is also used to determine tax liability for the purpose of other taxes, such as the gift and inheritance tax, car tax, municipal tax and social security contributions. Each above-mentioned tax has its own notion of residence. The different concepts of residence are compared with the residence concept that is used for income tax purposes. The comparison led to the observation that the residence concept for income tax purposes can impact on the other residence concepts. Usually residence for other tax purposes does not impact on the residence status for income tax purposes. However, the tax authorities claim that belonging to the Finnish social security system is a substantial tie according to the three-year rule. The Finnish rules on residence for income tax purposes are in many ways interesting in comparison to other countries rules on residence. A comparison has been made with Sweden, Norway, Denmark, Germany, the United Kingdom and the USA. Most of the above-mentioned countries have fairly recently amended and modernized their rules on residence. The comparison demonstrates that the Finnish rules on residence are outdated and in need of reformation. For instance, nationality does not carry any weight when determining tax liability in most other countries (except for the USA). When a Finnish national moves abroad, he is usually subject to full tax liability in the country of arrival, and at the same time subject to full tax liability in Finland due to the three-year rule. The resulting dual residence is solved by tax treaty, provided that the countries have concluded a treaty. For tax treaty purposes a person can only have one tax treaty residence at a time. Residence for tax treaty purposes is determined through the tie breaker in article 4(2). The state of residence has the primary right to tax the individual. The tie breaker is, however, problematic, since the criteria on which residence is decided are partly ambiguous and can be interpreted in different ways. Therefore the general rules on tax treaty interpretation have to be considered. Rules on tax treaty interpretation can be found in domestic legislation, international law, the Vienna convention, article 3(2) of tax treaties, and in the commentaries to the model tax convention. Some of the rules on interpretation can lead to different outcomes. The parties can also have diverging information about the individual s personal circumstances. Therefore it is possible that two countries cannot reach an agreement on which country should be the individual s state of residence according to article 4. When both countries claim to be the state of residence, the conflict shall be settled by the mutual agreement procedure in article 25 of the tax treaty. The mutual agreement procedure is time consuming and results cannot be guaranteed. In Finland there are no publications by the tax authorities on the mutual agreement procedure, and the procedure is hence not very well known. Therefore, I have tried to describe how the mutual agreement procedure is executed in practice. In 2008 the OECD added an arbitration clause to its model convention as a final means to solve tax treaty disputes that have not been solved by the mutual agreement procedure. Finland has not, however, included the clause in its treaties. Dual residence can result in several different consequences for the taxation of individuals, and the possible consequences are analysed in this thesis. The taxation of dual resident individuals can vary greatly from one situation to another depending on domestic legislation in both countries of residence, the type of income, the source of income, the tax treaties articles and the interpretation of the tax treaty. The taxation of dual resident persons can be divided into situations where no tax treaty has been concluded, a tax treaty exists and Finland is not the state of residence, and situations where both countries claim residence status according to the tax treaty. Some Finnish tax treaties include the three-year rule in article 23. According to the clause the source country is granted a more comprehensive, but secondary, right to tax persons who are resident according to domestic tax law, although the residence state for tax treaty purposes is in the other country. To demonstrate the impact of dual residence on the taxation of individuals, the taxation in Finland of interest, dividend, capital gains, salary and pensions is described through practical examples. Situations of dual residence can also have other tax implications, e.g. is there a progressive impact on other income, and how are deductions and losses taken into account when Finland is not the state of residence according to article 4? Dual residence does not necessarily cause double taxation as a result of national rules on credit and exemption and the elimination of double taxation. The concluding chapter sheds light on some of the most urgent problems in the current legislation on residence and presents some suggestions for improvements. The rules on residence in the domestic income tax act are scrutinized in detail. It is suggested that the nationality criterion in the three-year rule is abolished, and that substantial ties are defined in the income tax act. Furthermore, it is also suggested that the national rules on the elimination of double taxation are elucidated and that the scale of application is extended. On the international level it is recommended that article 3(2) in the OECD model tax convention is amended to primarily recommend an interpretation according to the context. Some minor adjustments are also presented to the articles on residence and mutual agreement.
  • Holopainen, Sari (Helsingin yliopisto, 2015)
    The boreal biome harbours a large share of the world s wetlands, and is the main breeding area for several duck species. Breeding habitats strongly influence duck reproduction. In this study, the habitat use of ducks and their breeding success was estimated in a boreal landscape in southern Finland. A review of duck habitat use in boreal wetlands was additionally made. Boreal forest lakes are normally considered stable environments, but from a duck s point of view both resource abundance and habitat quality in the lakes may differ from one year to another. In this study the vegetation of boreal freshwater lakes was found to slowly change during the 20-year study period. Beavers (Castor canadensis) caused pronounced alterations in the lakes by flooding them. Flooding rendered lake vegetation structure more luxuriant and increased the lake use by ducks. In general, duck brood lake use was positively associated with both the coverage of wide belts of tall emergent plants and the abundance of emerging insects and aquatic invertebrates. The relative importance of these factors varied between species. The brood production of common goldeneyes (Bucephala clangula) was regulated by density dependence per se, but fluctuated with food availability per capita. No spatial density-dependent effects were found for the common teal (Anas crecca), but the breeding success was instead explained well by habitat quality variation. Both food and flood abundance had a positive effect, but different variables seemed to operate during different phases of the breeding season. Many aspects of boreal breeding ducks are still poorly studied. Especially lacking are studies concerning duckling survival and the effects of anthropogenic actions on duck habitat use. This research underlines the importance of high quality habitats for breeding duck populations in the boreal landscape. The varying habitat requirements of duck species should be considered when implementing wetland management.
  • Monaco,Danilo (2000)
    Even though trade wars between Italy and France were definitely not a new phenomenon, when in 1969 the six members of the EEC decided to lay down the foundations of the wine common market, they hardly imagined the consequences that this kind of decision would have implied later on. For the first time ever French leadership was seriously threatened by import wines: by the spring 1975, when the first symptoms of overproduction appeared, the stage was set for the harshest trade conflict ever occured between two of the major partners of the common market area. Accusations of despicable economic practices hampering the principle of free trade were facing claims of illegal dumping exercises. Starting from a simple model on reciprocal dumping developed by Brander and Krugman (1983), this paper analyses the impact on dumping practices among economies with imperfectly competitive industries and firms producing homogeneous output. Particular emphasis is given to the problem of market leadership and of modelling trade as a multi-stage game where retaliation plays a fundamental role. The impact of different strategic tools as tariffs and subsidies is analysed, together with the overall effect of trade or autarky on overall welfare. While the theory often suggest equivocal payoffs, when considering the case of France-Italy wine trade and in the light of available evidence, the long run gains brought about to French consumers in the form of lower prices, reduced monopoly power and increased competition seem to have outweighed the losses incurred by its producers. Even though rationale for trade inhibiting practices has been in this paper theoretically shown to be sound, we have seen that retaliation often wipes off the benefits coming about through tariffs, subsidies and the likes. Ultimately, all the argumentation introduced in this paper braces more or less directly the free trade solution, since trade increases welfare through the effect of a reduced degree of monopoly in each country. This is a solution desirable under the pure economic point of view.
  • Rantala, Kati (2001)
    Studien analyserar modernistisk bildkonstfostran, som riktar sig till ungdomar. Denna fostran är upplysande, universaliserande och avskild från övrig samhällelig eller konstteoretisk diskussion. Enligt pedagogiken ökar konstaktiviteter förmågan att uttrycka sig fritt och individuellt. Detta medför att eleverna utvecklar sin personlighet, mognar andligt och lär sig leva ett etisk acceptabelt liv. Studien redogör för hur bildkonstfostran möter och försöker påverka den unge eleven och hans individualitet. Därutöver dryftar studien de utmaningar dagens samhälle ställer på bildkonstfostran: det ökade medvetandet om svårigheten att definiera konst och det allmänna goda, den ständiga betoningen av individens rätt att välja samt ungdomarnas egna visuella och estetiska kulturer. Materialet består av intervjuer med bildkonstelever och deras lärare, basläroplanen i konst samt intervjumaterial om nutidskonst och andra fritidsaktiviteter. I analysen tolkas betydelser och talesätt som ingår i materialet. Bildkonstfostran är en institution som eftersträvar det allmänna goda. Samtidigt försöker den legitimera sin verksamhet. Utan begreppet konst klarar sig institutionen inte. Detta ger upphov till retoriska problem och återvändsgränder: idén om konstens positiva verkan förpliktar konstpedagogerna att förse eleverna med färdigheter, som bottnar i sättet att uppfatta konst. För att skilja konsten från övrig symbolisk och produktiv verksamhet uppfattas den, i enlighet med traditionell estetik, som ett bildformspråk och som ett sätt att gestalta världen. Å andra sidan anses konsten vara ett sätt att fritt uttrycka känslor eller rentav kulminationen av mänsklig utveckling. I en mångkulturell debatt definieras konsten ofta som något som alltid existerat i alla kulturer. Men vad är i så fall inte konst? När "konst" förknippas med individens självuttryck har vi att göra med en några sekel lång social konstruktion. Eleverna tillägnar sig lätt lärarnas individualiserande talesätt. Uttrycket "du måste själv komma fram till det" beskriver lärarna lika väl som eleverna; som mål är det individuella uttrycket en paradox. Å andra sidan är det en självklarhet; eleverna framställer unika bilder och ger dem egna betydelser. När eleverna bedömer sina konkreta arbeten vill de veta hur deras färdigheter utvecklas. De vill utvärdera sin skicklighet, varvid tillfredsställelsen med sig själva grundar sig på att de flexibelt lär sig de regler och färdigheter som deras aktiviteter bygger på.
  • Torppa, Kaisa (2014)
    The purpose of this thesis was to examine the diversity and species composition of dung beetle (Scarabaeinae) communities in degraded rainforest landscapes in southeastern Madagascar. Several studies elsewhere in the world have revealed that forest-dwelling dung beetle communities and especially large species suffer from forest degradation and fragmentation by decreased species diversity. The most important factors affecting community structure of forest-dwelling dung beetles are habitat area, connectivity and vegetation quality i.e. microclimate. The hypothesis of this study was that the situation is the same in Madagascar. As dung beetles provide several important ecosystem services, like nutrient cycling and bioturbation, loss of dung beetle diversity imposes a secondary threat to the extraordinary nature of Madagascar by decreasing the regeneration ability of vegetation. Material for the study was collected in forest fragments of different size and quality between two areas of primary tropical rainforest – Ranomafana National Park and Vatovavy mountain – in November and December 2011 and January 2012. The sampling was conducted by transects of 30–60 fish- or carrion-baited pitfall traps which were set up in 55 localities in the study area. In each locality, several variables were measured to describe the vegetation and microclimatic conditions. The variables included temperature, humidity, estimate of vegetation quality by 6 observation-based classes, vegetation density, hights of three clearly visible vegetation layers, altitude and slope steepness. In addition, connectivities were measured for the localities using GIS and a satellite image –based vegetation classification. In order to demonstrate the differences between certain localities the study sites were divided into seven zones in terms of their distance from the Ranomafana National Park, average connectivity of the transects and elevation. Altogether 4,199 individuals belonging to 24 species were collected. Six of the species are currently under identification process in the Paris Museum of Natural History. According to the preliminary results they include two species new to science. Largest numbers of species were collected from good quality fragments between Ranomafana and Vatovavy. Also, a clear transition zone in species composition was detected a few kilometers west from Vatovavy, where altitude changes sharply. The study reveals that the species assemblages in the forest fragments and degraded forest areas are surprisingly species rich. This may, however, be partly because of extinction debt, and many of the still surviving species may soon die out due to restricted dispersal possibilities. Connectivity and vegetation quality were shown to have an effect on Canthonini species richness, with less species in less connected areas and lower vegetation quality. Vegetation quality was also shown to have an impact on the proportions of species with different body length: more small and medium-sized (< 8 mm) species were found in fragments where vegetation was more degraded. In addition to revealing how rainforest fragmentation and degradation affect local communities, the study gives interesting information about the distribution of certain species of Epilissus (Scarabaeinae: Canthonini). It has been known before that four species of Epilissus show elevational differentiation in their occurrence in Ranomafana. In this study, two more species of the same genus, E. prasinus and E. emmae obscurpennis, were shown to continue this pattern in lower elevations near Vatovavy mountain, about 50 kilometers east of Ranomafana.
  • Viljanen, Heidi (Helsingin yliopisto, 2009)
    The traditional aim of community ecology has been to understand the origin and maintenance of species richness in local communities. Why certain species occur in one place but not in another, how ecologically apparently similar species use resources, what is the role of the regional species pool in affecting species composition in local communities, and so forth. Madagascar offers great opportunities to conduct such studies, since it is a very large island that has been isolated for tens of million of years. Madagascar has remarkable faunal and floral diversity and species level endemism reaches 100% in many groups of species. Madagascar is also exceptional for endemism at high taxonomic levels and for the skewed representation of many taxa in comparison with continental faunas. For example, native ungulates that are dominant large herbivorous mammals on the African continent are completely lacking in Madagascar. The largest native Malagasy herbivores, and the main dung producers for Malagasy dung beetles, are the endemic primates, lemurs. Cattle was introduced to Madagascar about 1,000 yrs ago and is today abundant and widespread. I have studied Malagasy dung beetle communities and the distributional patterns of species at several spatial scales and compared the results with comparable communities in other tropical areas. There are substantial differences in dung beetle communities in Madagascar and elsewhere in the tropics in terms of the life histories of the species, species ecological traits, local and regional species diversities, and the sizes of species geographical ranges. These differences are attributed to Madagascar s ancient isolation, large size, heterogeneous environment, skewed representation of the mammalian fauna, and recent though currently great human impact.
  • Wirta, Helena (Helsingin yliopisto, 2009)
    Speciation on islands is affected by island size and the range of habitats and resources available and often also by limited interactions with other taxa. An ancestral population may evolve into a large number of species via an adaptive radiation. In Madagascar, most groups of animals and plants have radiated on the island, having arrived via oceanic dispersal during the long isolation of Madagascar. Characteristic features of Malagasy biota are exceptionally high level of endemism, high species richness as well as lack of many higher taxa that are dominant on the African mainland. Malagasy dung beetles are dominated by two tribes, Canthonini and Helictopleurina, with more than 250 endemic species. In this thesis I have reconstructed molecular phylogenies for the two tribes using several gene regions and different phylogenetic methods. Evolution of closely related species and among populations of the same species was examined with haplotype networks. The Malagasy Canthonini consists of three large lineages, while Helictopleurina forms a monophyletic group. The ancestors of each of the four clades colonised Madagascar at different times during Cenozoic. The subsequent radiations differ in terms of the number of extant species (from 37 to more than 100) and the level of ecological differentiation. In addition, Onthophagini (6 species) and Scarabaeini (3) have colonised Madagascar several times, but they have not radiated and the few species have not entered forests where Canthonini and Helictopleurina mostly occur. Among the three Canthonini radiations, speciation appears to have been mostly allopatric in the oldest and the youngest clades, while in the Epactoides clade sister species have diverged in their ecologies but have similar geographical distributions, indicating that speciation may have occurred in regional sympatry. The most likely isolating mechanisms have been rivers and forest refugia during dry and cool geological periods. Most species are generalists feeding on both carrion and dung, and competition among ecologically similar species may prevent their coexistence in the same communities. Some species have evolved to forage in the canopy and a few species have shifted to use cattle dung, a new resource in the open habitats following the introduction of cattle 1500 years ago. The latter shift has allowed species to expand their geographical ranges.
  • Hyvärinen, Heini (2010)
    Johdanto: Ikääntyessä iholla tapahtuva D-vitamiininmuodostus heikkenee ja lihakset ja luusto haurastuvat. Heikko lihaskunto on yhteydessä kaatumisriskiin, ja kaatuminen on yleisin syy vanhusten murtumiin. Monissa tutkimuksissa on osoitettu, että luustovaikutustensa lisäksi D-vitamiinilla on vaikutuksia luurankolihakseen. D-vitamiinihoidon on osoitettu vähentävän kaatumisia, mikä saattaa osin selittyä parantuneen tasapainon kautta. Joissakin tutkimuksissa on havaittu heikko tilastollinen yhteys Dvitamiinin ja kroonisen kivun välillä. D-vitamiinin puutokseen liitettyjä kipuja on esitetty luustoperäisiksi, mutta D-vitamiinin lihasvaikutukset huomioiden ne saattavat olla ainakin osin lihasperäisiä. Tavoitteet: Tämän poikkileikkaustutkimuksen tavoitteena oli tutkia, onko seerumin 25-hydroksi-Dvitamiinipitoisuus (25OHD) yhteydessä lihastoimintoihin itsenäisesti kotona asuvilla reumatauteja sairastavilla yli 50-vuotiailla. Hypoteesina oli, että D-vitamiinin puutos on yhteydessä heikentyneisiin neuromuskulaarisiin lihastoimintoihin, joita tässä tutkimuksessa mitattiin tasapainon perusteella. Aineisto ja menetelmät: Tutkimukseen rekrytoitiin yli 50-vuotiaita, koska tässä kohderyhmässä lihastoimintojen heikentymisen ja D-vitamiinin puutoksen odotettiin olevan yleisiä. Tutkittavien tuli kuitenkin olla kohtalaisen hyväkuntoisia, jotta he jaksaisivat fyysiset testit ja tutkimuksen mahdollisesti aiheuttaman henkisen rasituksen. Siksi lihastoimintojen ongelmia kuvaamaan valittiin polymyalgia rheumaticaa sairastavia, itsenäisesti kotona asuvia ihmisiä. Tutkimukseen osallistui myös joitakin yli 50- vuotiaita fibromyalgiaa ja nivelreumaa sairastavia henkilöitä. Seerumin 25OHD-pitoisuus määritettiin EIA-menetelmällä (IDS, UK). D-vitamiinin yhteyttä tutkittiin tasapainoon (Rombergin vakio tasapainolevyllä) ja lihasvoimaan (puristusvoima molempien käsien parhaan tuloksen keskiarvona, jalkojen nopeusvoima hyppylevyllä), kipuun ja toimintakykyyn. Tilastomenetelminä käytettiin ristiintaulukointia, t-testiä, lineaarista regressiota, logistista regressiota ja Pearsonin korrelaatiota. Tulokset: Tutkimukseen osallistui 47 henkilöä, joista viisi oli miehiä. Potilaat olivat 53-81 -vuotiaita (keski-ikä 70 v) ja hieman ylipainoisia (BMI 28). 25OHD oli keskimäärin 64 nmol/l. Ravitsemustila oli keskimäärin hyvä (MNA-pisteet 24). 25OHD oli alle 50 nmol/l 32 %:lla ja vastaavasti alle 75 nmol/l 74 %:lla tutkittavista. Potilaista 83 % käytti D-vitamiinivalmistetta. 25OHD korreloi positiivisesti ravitsemustilan (MNA) ja käänteisesti tasapainon ja kiputiheyden kanssa. 25OHD, ikä, sukupuoli ja MNA-pisteet selittivät 13,9 % (adjusted r2) huojunnan vaihtelusta ja 14,5 % (r2 Cox & Snell) kiputiheyden vaihtelusta. Ainoastaan 25OHD-pitoisuudella oli tilastollisesti merkitsevä itsenäinen selitysosuus huojuntaan (p = 0,024) ja kiputiheyteen (p = 0,045). Niillä, joilla 25OHD oli vähintään 75 nmol/l, oli 83 % pienempi riski kärsiä päivittäisestä kivusta kuin niillä, joilla 25OHD-pitoisuus oli alle 75 nmol/l. Lihasvoimalla, lihasmassalla ja kivun voimakkuudella ei havaittu yhteyttä D-vitamiinistatukseen. Johtopäätökset: Tässä tutkimuksessa reumatauteja sairastavien yli 50-vuotiaiden potilaiden matalat 25OHD-pitoisuudet olivat yhteydessä tasapainovaikeuksiin ja päivittäisiin kipuihin. Lihasmassa ja lihasvoima eivät olleet yhteydessä D-vitamiinistatukseen. Löydösten pohjalta olisi tulevaisuudessa tarpeen tutkia tarkemmin D-vitamiinikorvaushoidon vaikutuksia tasapainomittareihin ja kiputiheyteen.
  • Kairema, Anna (Helsingin yliopisto, 2013)
    This dissertation brings contribution to two interrelated topics. The first contribution concerns the so-called systems of dyadic cubes in the context of metric spaces. Second contribution is applications to one and two weight norm inequalities for linear and sublinear positive integral operators. Both of the topics are important in harmonic analysis and an ongoing area of study. The main novelties of the presented works consist of improving and extending existing results into more general frameworks. The work consists of four research articles and an introductory part. The first two articles, written in collaboration with T. Hytönen, study systems of dyadic cubes in metric spaces. In the Euclidean space, dyadic cubes are well-known and define a convenient structure with useful covering and intersection properties. Such dyadic structures are central especially in the modern trend of harmonic analysis. In the first article extensions of these structures are constructed in general geometrically doubling metric spaces. These consist of a refinement of existing constructions and a completely new construction of finitely many adjacent dyadic systems which behave like "translates" of a fixed system but without requiring a group structure. In this context, "cubes" are not properly cubes but rather more complicated sets that collectively have properties reminiscent of those in the Euclidean case. However, it is natural to ask what type of sets could or should be regarded cubes. In the second paper, we give a complete answer to this question in the general framework of a geometrically doubling metric space making use of the "plumpness" notion already appeared in the geometric measure theory. From another side; the two latter articles study weighted norm inequalities. Via the new construction of adjacent dyadic systems, weighted estimates for positive integral operators are obtained in a general framework. In the third paper, the two-weight problem is investigated for potential-type operators. Both strong and weak type estimates are characterized by "testing type" conditions: to show the full norm inequality it suffices to test the desired estimate on a specific class of simple test functions only. The results improve some previous results in the sense that the considered ambient space is more general (with more general measures and no additional geometric assumptions) and the testing is over a countable collection of test function only (instead of a significantly larger collection appearing in the previous works on the topic). The main technical novelty of the proof is a decomposition of the operator, along dyadic systems giving rise to certain finitely many "dyadic" versions of the original operator. In the fourth article, the focus is on sharp constant estimates for generalized fractional integral operators. A positive answer and its sharpness are given in the context of a space of homogeneous type. The result is reduced to weak-type inequalities using the results in the third paper. The sharpness requires a construction of functions that locally behave similarly to the basic power functions on the Euclidean space. The result extends a recent Euclidean result. Keywords: dyadic cube, adjacent dyadic systems, metric space, space of homogeneous type, potential type operator, testing condition, weighted norm inequality, sharp bound
  • Luther, Fred (1945)