67 resultados para common pool resources


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The purpose of the present study was to increase understanding of the interaction of rural people and, specifically, women with the environment in a dry area in Sudan. The study that included both nomadic pastoralists and farmers aimed at answering two main research questions, namely: What kinds of roles have the local people, and the women in particular, had in land degradation in the study area and what kinds of issues would a gender-sensitive, forestry-related environmental rehabilitation intervention need to consider there? The study adopted the definition of land degradation as proposed by the United Nations Convention to Combat Desertification (UNCCD), which describes land degradation as reduction or loss the biological or economic productivity and complexity of land in arid, semi-arid and dry sub-humid areas. The Convention perceives desertification as land degradation. The dry study area in Sudan, South of the Sahara, has been the subject of land degradation or desertification discussions since the 1970s, and other studies have been also conducted to assess the degradation in the area. Nevertheless, the exact occurrence, scale and local significance of land degradation in the area is still unclear. This study explored how the rural population whose livelihood depended on the area, perceived environmental changes occurring there and compared their conceptions with other sources of information of the area such as research reports. The main fieldwork methods included interviews with open-ended questions and observation of people and the environment. The theoretical framework conceptualised the rural population as land users whose choices of environmental activities are affected by multiple factors in the social and biophysical contexts in which they live. It was emphasised that these factors have their own specific characteristics in different contexts, simultaneously recognising that there are also factors that generally affect environmental practices in various areas such as the land users' environmental literacy (conceptions of the environment), gender and livelihood needs. The people studied described that environmental changes, such as reduced vegetation cover and cropland production, had complicated the maintenance of their livelihoods in the study area. Some degraded sites were also identified through observations during the fieldwork. Whether a large-scale reduction of cropland productivity had occurred in the farmers' croplands remained, however, unclear. The study found that the environmental impact of the rural women's activities varied and was normally limited. The women's most significant environmental impact resulted from their cutting of trees, which was likely to contribute, at least in some places, to land degradation, affecting the environment together with climate and livestock. However, when a wider perspective is taken, it becomes questionable whether the women have really played roles in land degradation, since gender, poverty and the need to maintain livelihood had caused them to conduct environmentally harmful activities. The women have had, however, no power to change the causes of their activities. The findings further suggested that an inadequate availability of food was the most critical problem in the study area. Therefore, an environmental programme in the area was suggested to include technical measures to increase the productivity of croplands, opportunities for income generation and readiness to co-operate with other programmes to improve the local people's abilities to maintain their livelihoods. In order to protect the environment and alleviate the women's work burden, the introduction of fuel-saving stoves was also suggested. Furthermore, it was suggested that increased planting of trees on homesteads would be supported by an easy availability of tree seedlings. Planting trees on common property land was, however, perceived as extremely demanding in the study area, due to scarcity of such land. In addition, it became apparent that the local land users, and women in particular, needed to allocate their labour to maintain the immediate livelihood of their families and were not motivated to allocate their labour solely for environmental rehabilitation. Nonetheless, from the point of view of the existing social structures, women's active participation in a community-based environmental programme would be rather natural, particularly among the farmer women who had already formed a women's group and participated in communal decision making. Forming of a women group or groups was suggested to further support both the farmer women's and pastoral women's active participation within an environmental programme and their general empowerment. An Environmental programme would need to acknowledge that improving rural people's well-being and maintaining their livelihood in the study area requires development and co-operation with various sectors in Sudan.

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The objectives of this study were to investigate the stand structure and succession dynamics in Scots pine (Pinus sylvestris L.) stands on pristine peatlands and in Scots pine and Norway spruce (Picea abies (L.) Karst.) dominated stands on drained peatlands. Furthermore, my focus was on characterising how the inherent and environmental factors and the intermediate thinnings modify the stand structure and succession. For pristine peatlands, the study was based on inventorial stand data, while for drained peatlands, longitudinal data from repeatedly measured stands were utilised. The studied sites covered the most common peatland site types in Finland. They were classified into two categories according to the ecohydrological properties related to microsite variation and nutrient levels within sites. Tree DBH and age distributions in relation to climate and site type were used to study the stand dynamics on pristine sites. On drained sites, the Weibull function was used to parameterise the DBH distributions and mixed linear models were constructed to characterise the impacts of different ecological factors on stand dynamics. On pristine peatlands, both climate and the ecohydrology of the site proved to be crucial factors determining the stand structure and its dynamics. Irrespective of the vegetation succession, enhanced site productivity and increased stand stocking they significantly affected the stand dynamics also on drained sites. On the most stocked sites on pristine peatlands the inter-tree competition seemed to also be a significant factor modifying stand dynamics. Tree age and size diversity increased with stand age, but levelled out in the long term. After drainage, the stand structural unevenness increased due to the regeneration and/or ingrowth of the trees. This increase was more pronounced on sparsely forested composite sites than on more fully stocked genuine forested sites in Scots pine stands, which further undergo the formation of birch and spruce undergrowth beneath the overstory as succession proceeds. At 20-30 years after drainage the structural heterogeneity started to decrease, indicating increased inter-tree competition, which increased the mortality of suppressed trees within stand. Peatland stands are more dynamic than anticipated and are generally not characterized by a balanced, self-perpetuating structure. On pristine sites, various successional pathways are possible, whereas on drained sites the succession has more uniform trend. Typically, stand succession proceeds without any distinct developmental stages on pristine peatlands, whereas on drained peatlands, at least three distinct stages could be identified. Thinnings had only little impact on the stand succession. The new information on stand dynamics may be utilised, e.g. in forest management planning to facilitate the allocation of the growth resources to the desired crop component by appropriate silvicultural treatments, as well as assist in assessing the effects of the climate change on the forested boreal peatlands.

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We described the patterns and extent of microsatellite DNA variation in historical and present-day Atlantic salmon (Salmo salar L.) stocks in the Baltic Sea and neighbouring areas, and in European whitefish (Coregonus lavaretus) ecotypes, populations and run-timing types in Finland. Moreover, the amount and pattern of genetic diversity in historical salmon populations before human impact were described, and the proportion of diversity maintained in the present hatchery stocks evaluated. Salmon populations in the Baltic Sea were, on average, significantly less variable than eastern Atlantic populations, and the diversity of landlocked populations (Lakes Vänern, Saimaa, Onega and Ladoga) was in turn significantly lower than that of anadromous salmon populations in the Baltic Sea populations. Within the Baltic Sea, the anadromous populations of Atlantic salmon formed three clear groups, corresponding to the northern (Gulf of Bothnia), eastern (Gulf of Finland and eastern Baltic Main Basin) and southern (western Baltic Main Basin) regions. Based on microsatellite data, three salmon population groups in the Baltic Sea were considered potentially different colonization lineages. In short- and long-term breeding programmes of Atlantic salmon, the average observed rate of loss of alleles was 4.9% and 2.0% per generation and the average rate of loss of heterozygosity was 1.4% and 1% per generation, respectively. When comparing the genetic parameters of stocks before and after hatchery breeding of several successive generations (Rivers Iijoki and Oulujoki), statistically significant changes in allele frequencies were common, while large wild stock in the Teno River has remained temporally very stable over 56 years. Despite the observed losses of genetic diversity in broodstock breeding, a large proportion of the genetic resources of the extirpated stocks are still conserved in the broodstocks. Genetic differentiation among European whitefish ecotypes was generally low, thus giving support to the hypothesis of one native European whitefish species in Fennoscandia. Among the ecotypes, the northern, large sparsely rakered, bottom-dwelling whitefish was the most unique. The known genetic differences in quantitative traits have thus either developed independently of potential phylogenetic lineages, or the lineages have mixed and the quantitative traits of the ecotypes, like gill-raker number, have later changed according to environment and selection pressures. Overall, genetic distances between the anadromous whitefish populations along the Finnish coast, especially in the Bothnian Bay area, were small. Wild whitefish populations studied had slightly higher allelic diversity than hatchery-reared populations in corresponding rivers.

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Buffer zones are vegetated strip-edges of agricultural fields along watercourses. As linear habitats in agricultural ecosystems, buffer strips dominate and play a leading ecological role in many areas. This thesis focuses on the plant species diversity of the buffer zones in a Finnish agricultural landscape. The main objective of the present study is to identify the determinants of floral species diversity in arable buffer zones from local to regional levels. This study was conducted in a watershed area of a farmland landscape of southern Finland. The study area, Lepsämänjoki, is situated in the Nurmijärvi commune 30 km to the north of Helsinki, Finland. The biotope mosaics were mapped in GIS. A total of 59 buffer zones were surveyed, of which 29 buffer strips surveyed were also sampled by plot. Firstly, two diversity components (species richness and evenness) were investigated to determine whether the relationship between the two is equal and predictable. I found no correlation between species richness and evenness. The relationship between richness and evenness is unpredictable in a small-scale human-shaped ecosystem. Ordination and correlation analyses show that richness and evenness may result from different ecological processes, and thus should be considered separately. Species richness correlated negatively with phosphorus content, and species evenness correlated negatively with the ratio of organic carbon to total nitrogen in soil. The lack of a consistent pattern in the relationship between these two components may be due to site-specific variation in resource utilization by plant species. Within-habitat configuration (width, length, and area) were investigated to determine which is more effective for predicting species richness. More species per unit area increment could be obtained from widening the buffer strip than from lengthening it. The width of the strips is an effective determinant of plant species richness. The increase in species diversity with an increase in the width of buffer strips may be due to cross-sectional habitat gradients within the linear patches. This result can serve as a reference for policy makers, and has application value in agricultural management. In the framework of metacommunity theory, I found that both mass effect(connectivity) and species sorting (resource heterogeneity) were likely to explain species composition and diversity on a local and regional scale. The local and regional processes were interactively dominated by the degree to which dispersal perturbs local communities. In the lowly and intermediately connected regions, species sorting was of primary importance to explain species diversity, while the mass effect surpassed species sorting in the highly connected region. Increasing connectivity in communities containing high habitat heterogeneity can lead to the homogenization of local communities, and consequently, to lower regional diversity, while local species richness was unrelated to the habitat connectivity. Of all species found, Anthriscus sylvestris, Phalaris arundinacea, and Phleum pretense significantly responded to connectivity, and showed high abundance in the highly connected region. We suggest that these species may play a role in switching the force from local resources to regional connectivity shaping the community structure. On the landscape context level, the different responses of local species richness and evenness to landscape context were investigated. Seven landscape structural parameters served to indicate landscape context on five scales. On all scales but the smallest scales, the Shannon-Wiener diversity of land covers (H') correlated positively with the local richness. The factor (H') showed the highest correlation coefficients in species richness on the second largest scale. The edge density of arable field was the only predictor that correlated with species evenness on all scales, which showed the highest predictive power on the second smallest scale. The different predictive power of the factors on different scales showed a scaledependent relationship between the landscape context and local plant species diversity, and indicated that different ecological processes determine species richness and evenness. The local richness of species depends on a regional process on large scales, which may relate to the regional species pool, while species evenness depends on a fine- or coarse-grained farming system, which may relate to the patch quality of the habitats of field edges near the buffer strips. My results suggested some guidelines of species diversity conservation in the agricultural ecosystem. To maintain a high level of species diversity in the strips, a high level of phosphorus in strip soil should be avoided. Widening the strips is the most effective mean to improve species richness. Habitat connectivity is not always favorable to species diversity because increasing connectivity in communities containing high habitat heterogeneity can lead to the homogenization of local communities (beta diversity) and, consequently, to lower regional diversity. Overall, a synthesis of local and regional factors emerged as the model that best explain variations in plant species diversity. The studies also suggest that the effects of determinants on species diversity have a complex relationship with scale.

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The current study of Scandinavian multinational corporate subsidiaries in the rapidly growing Eastern European market, due to their particular organizational structure, attempts to gain some new insights into processes and potential benefits of knowledge and technology transfer. This study explores how to succeed in knowledge transfer and to become more competitive, driven by the need to improve transfer of systematic knowledge for the manufacture of product and service provisions in newly entered market. The scope of current research is exactly limited to multinational corporations, which are defined as enterprises comprising entities in two or more countries, regardless of legal forms and field of activity of those entities, and which operate under a system of decision-making permitting coherent policies and a common strategy through one or more decision-making centers. The entities are linked, by ownership, and able to exercise influence over the activities of the others; and, in particular, to share the knowledge, resources, and responsibilities with others. The research question is "How and to which extent can knowledge-transfer influence a company's technological competence and economic competitiveness?" and try to find out what particular forces and factors affect the development of subsidiary competencies; what factors influence the corporate integration and use of the subsidiary's competencies; and what may increase competitiveness of MNC pursuing leading position in entered market. The empirical part of the research was based on qualitative analyses of twenty interviews conducted among employees in Scandinavian MNC subsidiary units situated in Ukraine, using structured sequence of questions with open-ended answers. The data was investigated by comparison case analyses to literature framework. Findings indicate that a technological competence developed in one subsidiary will lead to an integration of that competence with other corporate units within the MNC. Success increasingly depends upon people's learning. The local economic area is crucial for understanding competition and industrial performance, as there seems to be a clear link between the performance of subsidiaries and the conditions prevailing in their environment. The linkage between competitive advantage and company's success is mutually dependent. Observation suggests that companies can be characterized as clusters of complementary activities such as R&D, administration, marketing, manufacturing and distribution. Study identifies barriers and obstacles in technology and knowledge transfer that is relevant for the subsidiaries' competence development. The accumulated experience can be implemented in new entered market with simple procedures, and at a low cost under specific circumstances, by cloning. The main goal is focused to support company prosperity, making more profits and sustaining an increased market share by improved product quality and/or reduced production cost of the subsidiaries through cloning approach. Keywords: multinational corporation; technology transfer; knowledge transfer; subsidiary competence; barriers and obstacles; competitive advantage; Eastern European market

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The objective of this thesis is to find out how dominant firms in a liberalised electricity market will react when they face an increase in the level of costs due to emissions trading, and how this will effect the price of electricity. The Nordic electricity market is chosen as the setting in which to examine the question, since recent studies on the subject suggest that interaction between electricity markets and emissions trading is very much dependent on conditions specific to each market area. There is reason to believe that imperfect competition prevails in the Nordic market, thus the issue is approached through the theory of oligopolistic competition. The generation capacity available at the market, marginal cost of electricity production and seasonal levels of demand form the data based on which the dominant firms are modelled using the Cournot model of competition. The calculations are made for two levels of demand, high and low, and with several values of demand elasticity. The producers are first modelled under no carbon costs and then by adding the cost of carbon dioxide at 20€/t to those technologies subject to carbon regulation. In all cases the situation under perfect competition is determined as a comparison point for the results of the Cournot game. The results imply that the potential for market power does exist on the Nordic market, but the possibility for exercising market power depends on the demand level. In season of high demand the dominant firms may raise the price significantly above competitive levels, and the situation is aggravated when the cost of carbon dioixide is accounted for. Under low demand leves there is no difference between perfect and imperfect competition. The results are highly dependent on the price elasticity of demand.

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This study Contested Lands: Land disputes in semi-arid parts of northern Tanzania. Case Studies of the Loliondo and Sale Division in the Ngorongoro District concentrates on describing the specific land disputes which took place in the 1990s in the Loliondo and Sale Divisions of the Ngorongoro District in northern Tanzania. The study shows the territorial and historical transformation of territories and property and their relation to the land disputes of the 1990s'. It was assumed that land disputes have been firstly linked to changing spatiality due to the zoning policies of the State territoriality and, secondly, they can be related to the State control of property where the ownership of land property has been redefined through statutory laws. In the analysis of the land disputes issues such as use of territoriality, boundary construction and property claims, in geographical space, are highlighted. Generally, from the 1980s onwards, increases in human population within both Divisions have put pressure on land/resources. This has led to the increased control of land/resource, to the construction of boundaries and finally to formalized land rights on village lands of the Loliondo Division. The land disputes have thus been linked to the use of legal power and to the re-creation of the boundary (informal or formal) either by the Maasai or the Sonjo on the Loliondo and Sale village lands. In Loliondo Division land disputes have been resource-based and related to multiple allocations of land or game resource concessions. Land disputes became clearly political and legal struggles with an ecological reference.Land disputes were stimulated when the common land/resource rights on village lands of the Maasai pastoralists became regulated and insecure. The analysis of past land disputes showed that space-place tensions on village lands can be presented as a platform on which spatial and property issues with complex power relations have been debated. The reduction of future land disputes will succeed only when/if local property rights to land and resources are acknowledged, especially in rural lands of the Tanzanian State.

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Territoriality is a central issue in indigenous peoples struggles. The territorial struggles involve struggles over the control of natural resources and over political participation and representation, but also over the perception of territorial rights and the symbolic representation of the territory. These struggles are carried through both in material and symbolic ways through recurring to different discourses and representations that provide legitimation for the territorial claims of the group. The study is located in the Northern Autonomous Atlantic Region of Nicaragua. The study concerns the territorial strategies, conceptions and practices of the indigenous people and other actors. Territorial conflicts exist between the autonomous region and the central government of Nicaragua, between mestizo settlers and indigenous people, between different indigenous groups, and between these and development agents such as conservation projects. The study focuses on how territorial discourses and representations are used to legitimate territorial control. Environmental, historical and cartographical discourses are the most important discourses recurred to. The influence of discourses and representations on the territorial practices and policies of the different actors, the links between the local struggles and global processes, and the broader structural factors impacting on the territorial struggles are also analysed. Among the structural factors are the problems related to land tenure and management and the use of natural resources, the advance of the agricultural frontier, the institutional weaknesses of the central and regional governments and the legislative processes. The territorial discourses are both recurred to in a strategic way and also grounded in local ideals and practices. The discourses have produced real effects for example in legislation, land tenure systems, political representation and environmental practices. Although the use of discourses and representations are an important power tool in territorial struggles, territorial control cannot be effectively accomplished merely through representing territorial claims in a legitimate way or through reforming legislation, as the conflicts are also largely a result of structural factors affecting the region. The fieldwork was carried out during a total of twelve months between 2000 and 2002. The research methods used were semi-structured interviews, participant observation and participatory research methods. A broad range of literary sources were also used to collect data. The study is located within the field of critical political geography with a discursive political ecology approach. It can be called a critical realist approach to the discursive analysis of indigenous territoriality.

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In this thesis we study a series of multi-user resource-sharing problems for the Internet, which involve distribution of a common resource among participants of multi-user systems (servers or networks). We study concurrently accessible resources, which for end-users may be exclusively accessible or non-exclusively. For all kinds we suggest a separate algorithm or a modification of common reputation scheme. Every algorithm or method is studied from different perspectives: optimality of protocols, selfishness of end users, fairness of the protocol for end users. On the one hand the multifaceted analysis allows us to select the most suited protocols among a set of various available ones based on trade-offs of optima criteria. On the other hand, the future Internet predictions dictate new rules for the optimality we should take into account and new properties of the networks that cannot be neglected anymore. In this thesis we have studied new protocols for such resource-sharing problems as the backoff protocol, defense mechanisms against Denial-of-Service, fairness and confidentiality for users in overlay networks. For backoff protocol we present analysis of a general backoff scheme, where an optimization is applied to a general-view backoff function. It leads to an optimality condition for backoff protocols in both slot times and continuous time models. Additionally we present an extension for the backoff scheme in order to achieve fairness for the participants in an unfair environment, such as wireless signal strengths. Finally, for the backoff algorithm we suggest a reputation scheme that deals with misbehaving nodes. For the next problem -- denial-of-service attacks, we suggest two schemes that deal with the malicious behavior for two conditions: forged identities and unspoofed identities. For the first one we suggest a novel most-knocked-first-served algorithm, while for the latter we apply a reputation mechanism in order to restrict resource access for misbehaving nodes. Finally, we study the reputation scheme for the overlays and peer-to-peer networks, where resource is not placed on a common station, but spread across the network. The theoretical analysis suggests what behavior will be selected by the end station under such a reputation mechanism.

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The Ideal of Volunteerism. An institutional approach to social welfare work in the parishes of the Diocese of Porvoo especially in the deaneries of Iitti and Tampere, Finland, in the years 1897-1923 Social welfare work (also known as diakonia) has achieved a high status in the Evangelical Lutheran Church of Finland. Since 1944, provisions of the Finnish Church Act have obliged each parish to employ at least one deacon or deaconess. This study sets out to examine the background and development of social welfare work in the Evangelical Lutheran Church of Finland from the 1890s to the 1920s, by which time social welfare work had become an established practice in the Church. The study investigates the development of social welfare work on the level of parishes. The main source material was collected from sixteen parishes in the Diocese of Porvoo especially in the deaneries of Iitti and Tampere. In the 1890s, two approaches were used in church social work in Finland. The dioceses of Kuopio, Savonlinna and Turku pursued a congregational approach to social work, while the Diocese of Porvoo employed an institutional approach, mainly because of the influence of Bishop Herman Råbergh. This study charts the formation of church social work in Finnish parishes, which took place during a period of tension between the two approaches. The institutional approach to church social work adopted by the Diocese of Porvoo was based on the German system of Asisters= houses@, in which deaconess institutes sent parish sisters to serve congregations. The parish or, in many cases, a separate association dedicated to church social work paid an annual fee to the deaconess institute, which took care of the parish sisters in old age. In the institutional approach, volunteers were recruited to carry out church social work. It was considered as inappropriate to use tax revenue or other public funding for church social work, which was supposed to be based on Christian love for one=s fellow humans and the needy, and for which only voluntary financial contributions were supposed to be used. In the congregational approach, church social work was directly based on the efforts of the parish. The approach relied on the administrative bodies of parishes and the Church, and tax revenue collected by the parishes, as well as other forms of public funding, could be used to carry out the social welfare work. The parishes employed deacons and deaconesses and paid their salaries. The approaches described above were not pursued in their ideal forms; instead, many variations existed. However, in principle, the social welfare work undertaken by the parishes of the Diocese of Porvoo was based on the institutional approach, while the congregational approach was largely employed elsewhere in Finland. Both of the approaches were viable. Parishes began to employ deacons and deaconesses as of the 1890s. The number of parishes which had hired a deacon or deaconess increased particularly in the 1910s, by which time 60% of parishes had employed one. This level was maintained until 1944 when each parish in the Evangelical Lutheran Church of Finland was obliged to employ a deacon or deaconess. Deaconesses usually worked as travelling nurses. The autonomous status of Finland as part of the Russian Empire did not give Finns the right to develop legislation on social affairs and health care. Consequently, the legislation process did not begin until Finland gained its independence in 1917. The social welfare work carried out by parishes and a number of voluntary organisations satisfied the emerging need for medical treatment in Finnish society. Neither the government nor the municipalities had sufficient resources to provide this treatment. Based on the ideal of volunteerism, the institutional social work practiced in the Diocese of Porvoo ran into serious difficulties at the end of the First World War. Because of severe inflation, prices began to rise as of 1915 and tripled in 1917-1918. During the same period, Finnish society went through a deep crisis which escalated into Civil War in spring 1918. This period of economic and social turmoil marked a turning-point which led to a weakening of the status of institutional social work in parishes. Voluntary efforts were no longer sufficient to maintain the practice. In contrast, congregational social work, which was based on public funding, was able to cope with the changes and survived the crisis. The approach to social work adopted by the Diocese of Porvoo turned out to be no more than a brief detour in the history of social work in the Evangelical Lutheran Church of Finland. At the start of the 1920s, the two approaches were integrated into a common vision for establishing church social work as a statutory practice in parishes.

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A vast amount of public services and goods are contracted through procurement auctions. Therefore it is very important to design these auctions in an optimal way. Typically, we are interested in two different objectives. The first objective is efficiency. Efficiency means that the contract is awarded to the bidder that values it the most, which in the procurement setting means the bidder that has the lowest cost of providing a service with a given quality. The second objective is to maximize public revenue. Maximizing public revenue means minimizing the costs of procurement. Both of these goals are important from the welfare point of view. In this thesis, I analyze field data from procurement auctions and show how empirical analysis can be used to help design the auctions to maximize public revenue. In particular, I concentrate on how competition, which means the number of bidders, should be taken into account in the design of auctions. In the first chapter, the main policy question is whether the auctioneer should spend resources to induce more competition. The information paradigm is essential in analyzing the effects of competition. We talk of a private values information paradigm when the bidders know their valuations exactly. In a common value information paradigm, the information about the value of the object is dispersed among the bidders. With private values more competition always increases the public revenue but with common values the effect of competition is uncertain. I study the effects of competition in the City of Helsinki bus transit market by conducting tests for common values. I also extend an existing test by allowing bidder asymmetry. The information paradigm seems to be that of common values. The bus companies that have garages close to the contracted routes are influenced more by the common value elements than those whose garages are further away. Therefore, attracting more bidders does not necessarily lower procurement costs, and thus the City should not implement costly policies to induce more competition. In the second chapter, I ask how the auctioneer can increase its revenue by changing contract characteristics like contract sizes and durations. I find that the City of Helsinki should shorten the contract duration in the bus transit auctions because that would decrease the importance of common value components and cheaply increase entry which now would have a more beneficial impact on the public revenue. Typically, cartels decrease the public revenue in a significant way. In the third chapter, I propose a new statistical method for detecting collusion and compare it with an existing test. I argue that my test is robust to unobserved heterogeneity unlike the existing test. I apply both methods to procurement auctions that contract snow removal in schools of Helsinki. According to these tests, the bidding behavior of two of the bidders seems consistent with a contract allocation scheme.

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The knowledge about the optimal rearing conditions, such as water temperature and quality, photoperiod and density, with the understanding of animal nutritional requirements forms the basis of economically stable aquaculture for freshwater crayfish. However, the shift from a natural environment to effective culture conditions induces several changes, not only at the population level, but also at the individual level. The social contacts between conspecifics increase with increasing animal density. The competition for limited resources (e.g. food, shelter, mates) is more severe with the presence of agonistic behaviour and may lead to unequal distribution of these. The objectives of this study were to: 1) study the distribution of a common food resource between communally reared signal crayfish (Pacifastacus leniusculus) and to assign potential feeding hierarchy on the basis of individual food intake measurements, 2) explore the possibilities of size distribution manipulations to affect population dynamics and food intake to improve growth and survival in culture and 3) study the effect of food ration and spatial distribution on food intake and to explore the effect of temperature and food ration on growth and body composition of freshwater crayfish. The feeding ranks between animals were assigned with a new method for individual food intake measurement of communally reared crayfish. This technique has a high feasibility and a great potential to be applied in crayfish aquaculture studies. In this study, signal crayfish showed high size-related variability in food consumption both among individuals within a group (inter-individual) and within individual day-to-day variation (intra-individual). Increased competition for food led to an unequal distribution of this resource and this may be a reason for large growth differences between animals. The consumption was significantly higher when reared individually in comparison with communal housing. These results suggest that communally housed crayfish form a feeding hierarchy and that the animal size is the major factor controlling the position in this hierarchy. The optimisation of the social environment ( social conditions ) was evaluated in this study as a new approach to crayfish aquaculture. The results showed that the absence of conspecifics (individual rearing vs. communal housing) affects growth rate, food intake and the proportion of injured animals, whereas size variation between animals influences the number and duration of agonistic encounters. In addition, animal size had a strong influence on the fighting success of signal crayfish reared in a social milieu with a wide size variation of conspecifics. Larger individuals initiated and won most of the competitions, which suggests size-based social hierarchy of P. leniusculus. This is further supported by the fact that the length and weight gain of smaller animals increased after size grading, maybe because of a better access to the food resource due to diminished social pressure. However, the high dominance index was not based on size under conditions of limited size variation, e.g. those characteristic of restocked natural populations and aquaculture, indicating the important role of behaviour on social hierarchy.

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Natural selection generally operates at the level of the individual, or more specifically at the level of the gene. As a result, individual selection does not always favour traits which benefit the population or species as a whole. The spread of an individual gene may even act to the detriment of the organism in which it finds. Thus selection at the level of the individual can affect processes at the level of the organism, group or even at the level of the species. As most behaviours ultimately affect births, deaths and the distribution of individuals, it seems inevitable that behavioural decisions will have an impact on population dynamics and population densities. Behavioural decisions can often involve costs through allocation of energy into behavioural strategies, such as the investment into armaments involved in fighting over resources or increased mortality due to injury or increased predation risk. Similarly, behaviour may act o to benefit the population, in terms of higher survival and increased fecundity. Examples include increased investment through parental care, choosing a mate based on the nuptial gifts they may supply and choosing territories in the face of competition. Investigating the impact of behaviour on population ecology may seem like a trivial task, but it is likely to have important consequences at different levels. For example, antagonistic behaviour may occasionally become so extreme that it increases the risk of extinction, and such extinction risk may have important implications for conservation. As a corollary, any such behaviour may also act as a macroevolutionary force, weeding out populations with traits which, whilst beneficial to the individuals in the short term, ultimately result in population extinction. In this thesis, I examine how behaviours, specifically conflict and competition over a resource and aspects of behaviour involved in sexual selection, can affect population densities, and what the implications are for the evolution and ecology of the populations in question. It is found that both behaviours related to individual conflict and mating strategies can have an effect at the level of the population, but that various factors, such as a feedback between selection and population densities or macroevolution caused by species extinctions, may act to limit the intensity of conflicts that we observe in nature.