35 resultados para top-down approach


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The objective of my thesis is to assess mechanisms of ecological community control in macroalgal communities in the Baltic Sea. In the top-down model, predatory fish feed on invertebrate mesograzers, releasing algae partly from grazing pressure. Such a reciprocal relationship is called trophic cascade. In the bottom-up model, nutrients increase biomass in the food chain. The nutrients are first assimilated by algae and, via food chain, increase also abundance of grazers and predators. Previous studies on oceanic shores have described these two regulative mechanisms in the grazer - alga link, but how they interact in the trophic cascades from fish to algae is still inadequately known. Because the top-down and bottom-up mechanisms are predicted to depend on environmental disturbances, such as wave stress and light, I have studied these models at two distinct water depths. There are five factorial field experiments behind the thesis, which were all conducted in the Finnish Archipelago Sea. In all the experiments, I studied macroalgal colonization - either density, filament length or biomass - on submerged colonization substrates. By excluding predatory fish and mesograzers from the algal communities, the studies compared the strength of the top-down control to natural algal communities. A part of the experimental units were, in addition, exposed to enriched nitrogen and phosphorus concentrations, which enabled testing of bottom-up control. These two models of community control were further investigated in shallow (<1 m) and deep (ca. 3 m) water. Moreover, the control mechanisms were also expected to depend on grazer species. Therefore different grazer species were enclosed into experimental units and their impacts on macroalgal communities were followed specifically. The community control in the Baltic rocky shores was found to follow theoretical predictions, which have not been confirmed by field studies before. Predatory fish limited grazing impact, which was seen as denser algal communities and longer algal filaments. Nutrient enrichment increased density and filament length of annual algae and, thus, changed the species composition of the algal community. The perennial alga Fucus vesiculosusA and the red alga Ceramium tenuicorne suffered from the increased nutrient availabilities. The enriched nutrient conditions led to denser grazer fauna, thereby causing strong top-down control over both the annual and perennial macroalgae. The strength of the top-down control seemed to depend on the density and diversity of grazers and predators as well as on the species composition of macroalgal assemblages. The nutrient enrichment led to, however, weaker limiting impact of predatory fish on grazer fauna, because fish stocks did not respond as quickly to enhanced resources in the environment as the invertebrate fauna. According to environmental stress model, environmental disturbances weaken the top-down control. For example, on a wave-exposed shore, wave stress causes more stress to animals close to the surface than deeper on the shore. Mesograzers were efficient consumers at both the depths, while predation by fish was weaker in shallow water. Thus, the results supported the environmental stress model, which predicts that environmental disturbance affects stronger the higher a species is in the food chain. This thesis assessed the mechanisms of community control in three-level food chains and did not take into account higher predators. Such predators in the Baltic Sea are, for example, cormorant, seals, white-tailed sea eagle, cod and salmon. All these predatory species were recently or are currently under intensive fishing, hunting and persecution, and their stocks have only recently increased in the region. Therefore, it is possible that future densities of top predators may yet alter the strengths of the controlling mechanisms in the Baltic littoral zone.

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In general, models of ecological systems can be broadly categorized as ’top-down’ or ’bottom-up’ models, based on the hierarchical level that the model processes are formulated on. The structure of a top-down, also known as phenomenological, population model can be interpreted in terms of population characteristics, but it typically lacks an interpretation on a more basic level. In contrast, bottom-up, also known as mechanistic, population models are derived from assumptions and processes on a more basic level, which allows interpretation of the model parameters in terms of individual behavior. Both approaches, phenomenological and mechanistic modelling, can have their advantages and disadvantages in different situations. However, mechanistically derived models might be better at capturing the properties of the system at hand, and thus give more accurate predictions. In particular, when models are used for evolutionary studies, mechanistic models are more appropriate, since natural selection takes place on the individual level, and in mechanistic models the direct connection between model parameters and individual properties has already been established. The purpose of this thesis is twofold. Firstly, a systematical way to derive mechanistic discrete-time population models is presented. The derivation is based on combining explicitly modelled, continuous processes on the individual level within a reproductive period with a discrete-time maturation process between reproductive periods. Secondly, as an example of how evolutionary studies can be carried out in mechanistic models, the evolution of the timing of reproduction is investigated. Thus, these two lines of research, derivation of mechanistic population models and evolutionary studies, are complementary to each other.

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The deterioration of surface waters is one of the most important issues in the environmental management of the European Union. Thus, the EU Water Framework Directive 2000/60/EC (WFD) requires “good ecological and chemical status” of surface waters by 2015 allowing only a slight departure from ecological reference conditions characterized by the biological communities typical for the conditions of minimal anthropogenic impact. The WFD requires the determination of ecological reference conditions and the present ecological status of surface waters. To meet this legislative demand, sedimentary diatom assemblages were used in these studies with various methods 1) to assess natural and human activity induced environmental changes, 2) to characterize background conditions 3) to evaluate the present ecological status and 4) to predict the future of the water bodies in the light of palaeolimnological data. As the WFD refers to all surface waters, both coastal and inland sites were included. Two long and two short sediment cores from the Archipelago Sea in the northern Baltic Sea were examined for their siliceous microfossils in order to assess (1) the Holocene palaeoenvironmental history and (2) the recent eutrophication of the area. The diatom record was divided into local diatom assemblage zones (LDAZ, long cores) and diatom assemblage zones (DAZ, short cores). Locally weighted weighted averaging regression and calibration (LWWA) was applied for the quantitative reconstruction of past TN concentrations (short cores). An age model for the long cores was constructed by using independent palaeomagnetic and AMS-14C methods. The short cores were dated using radiometric (210Pb, 226Ra and 137Cs) methods. The long cores date back to the early history of the Archipelago Sea, which was freshwater – no salinity increase referable to the brackish phase of the Yoldia Sea is recognized. The nutrient status of the lacustrine phase was slightly higher in the Archipelago Sea than in the Baltic Proper. Initial brackish-water influence is observed at 8 150 ±80 cal. BP (LDAZ4), but fully brackish conditions were established at 7 700 ±80 cal. BP (LDAZ5). The diatom assemblages indicate increasing salinity, warming climate and possible eutrophic conditions during the lacustrine to brackish-water transition. The decreasing abundance of Pseudosolenia calcar-avis (Schultze) Sundström and the increasing abundance of the ice-cover indicator species Pauliella taeniata (Grunow) Round and Basson indicate decreasing salinity and climatic cooling after ca. 5 000 cal. BP. Signs of eutrophication are visible in the most recent diatom assemblage zones of both short cores. Diatom-inferred total nitrogen (DI-TN) reconstructions partially fail to trace the actual measured total nitrogen concentrations especially from the late 1980s to the mid 1990s. This is most likely due to the dominating diatom species Pauliella taeniata, Thalassiosira levanderi Van Goor and Fragilariopsis cylindrus (Grunow) W. Krieger being more influenced by factors such as the length of the ice-season rather than nutrient concentrations. It is concluded that the diatom assemblages of the study sites are principally governed by climate fluctuations, with a slight influence of eutrophication visible in the most recent sediments. There are indications that global warming, with reduced ice cover, could impact the spring blooming diatom species composition in the Archipelago Sea. In addition, increased sediment accumulation in the early 90s coincides with the short ice-seasons suggesting that warming climate with decreasing ice-cover may increase sedimentation in the study area. The diverse diatom assemblages dominated by benthic species (54 %) in DAZ1 in the Käldö Fjärd core can be taken as background diatom assemblages for the Archipelago Sea. Since then turbidity has increased and the diatom assemblages have been dominated by planktonic diatoms from around the mid 1800s onwards. The reconstructed reference conditions for the total nitrogen concentrations fluctuate around 400 μg l-1. Altogether two short sediment cores and eight short cores for top-bottom analysis were retrieved from Lake Orijärvi and Lake Määrjärvi to assess the impact of the acid mine drainage (AMD) derived metals from the Orijärvi mine tailings on the diatom communities of the lakes. The Cu (Pb, Zn) mine of Orijärvi (1757 – 1956) was the first one in Finland where flotation techniques (1911 – 1955) were used to enrich ore and large quantities of tailings were produced. The AMD derived metal impact to the lakes was found to be among the heaviest thus far recorded in Finland. Concentrations of Cu, Pb and Zn in Lake Orijärvi sediments are two to three orders of magnitude higher than background values. The metal inputs have affected Lake Orijärvi and Lake Määrjärvi diatom communities at the community levels through shifts in dominant taxa (both lakes) and at the individual level through alteration in frustule morphology (Lake Orijärvi). At present, lake water still has elevated heavy metal levels, indicating that the impact from the tailings area continues to affect both lakes. Lake Orijärvi diatom assemblages are completely dominated by benthic species and are lacking planktonic diatoms. In Lake Määrjärvi the proportion of benthic and tychoplanktonic diatoms has increased and the planktonic taxa have decreased in abundance. Achnanthidium minutissimum Kützing and Brachysira vitrea (Grun.) R. Ross in Hartley were the most tolerant species to increased metal concentrations. Planktonic diatoms are more sensitive to metal contamination than benthic taxa, especially species in the genus Cyclotella (Kützing) Brébisson. The ecological reference conditions assessed in this study for Lake Orijärvi and Lake Määrjärvi comprise diverse planktonic and benthic communitites typical of circumneutral oligotrophic lakes, where the planktonic diatoms belonging to genera Cyclotella , Aulacoseira Thwaites, Tabellaria Ehrenberg and Asterionella Hassall dominate in relative abundances up to ca. 70%. The benthic communities are more diverse than the planktonic consisting of diatoms belonging to the genera Achnanthes Bory, Fragilaria Lyngbye and Navicula St. Vincent. This study clearly demonstrates that palaeolimnological methods, especially diatom analysis, provide a powerful tool for the EU Water Frame Work Directive for defining reference conditions, natural variability and current status of surface waters. The top/bottom approach is a very useful tool in larger-scale studies needed for management purposes. This “before and after” type of sediment sampling method can provide a very time and cost effective assessment of ecological reference conditions of surface waters.

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The general goal of the present work was to study whether spatial perceptual asymmetry initially observed in linguistic dichotic listening studies is related to the linguistic nature of the stimuli and/or is modality-specific, as well as to investigate whether the spatial perceptual/attentional asymmetry changes as a function of age and sensory deficit via praxis. Several dichotic listening studies with linguistic stimuli have shown that the inherent perceptual right ear advantage (REA), which presumably results from the left lateralized linguistic functions (bottom-up processes), can be modified with executive functions (top-down control). Executive functions mature slowly during childhood, are well developed in adulthood, and decline as a function of ageing. In Study I, the purpose was to investigate with a cross-sectional experiment from a lifespan perspective the age-related changes in top-down control of REA for linguistic stimuli in dichotic listening with a forced-attention paradigm (DL). In Study II, the aim was to determine whether the REA is linguistic-stimulus-specific or not, and whether the lifespan changes in perceptual asymmetry observed in dichotic listening would exist also in auditory spatial attention tasks that put load on attentional control. In Study III, using visual spatial attention tasks, mimicking the auditory tasks applied in Study II, it was investigated whether or not the stimulus-non-specific rightward spatial bias found in auditory modality is a multimodal phenomenon. Finally, as it has been suggested that the absence of visual input in blind participants leads to improved auditory spatial perceptual and cognitive skills, the aim in Study IV was to determine, whether blindness modifies the ear advantage in DL. Altogether 180-190 right-handed participants between 5 and 79 years of age were studied in Studies I to III, and in Study IV the performance of 14 blind individuals was compared with that of 129 normally sighted individuals. The results showed that only rightward spatial bias was observed in tasks with intensive attentional load, independent of the type of stimuli (linguistic vs. non-linguistic) or the modality (auditory vs. visual). This multimodal rightward spatial bias probably results from a complex interaction of asymmetrical perceptual, attentional, and/or motor mechanisms. Most importantly, the strength of the rightward spatial bias changed as a function of age and augmented praxis due to sensory deficit. The efficiency of the performance in spatial attention tasks and the ability to overcome the rightward spatial bias increased during childhood, was at its best in young adulthood, and decreased as a function of ageing. Between the ages of 5 and 11 years probably at first develops movement and impulse control, followed by the gradual development of abilities to inhibit distractions and disengage attention. The errors especially in bilateral stimulus conditions suggest that a mild phenomenon resembling extinction can be observed throughout the lifespan, but especially the ability to distribute attention to multiple targets simultaneously decreases in the course of ageing. Blindness enhances the processing of auditory bilateral linguistic stimuli, the ability to overcome a stimulus-driven laterality effect related to speech sound perception, and the ability to direct attention to an appropriate spatial location. It was concluded that the ability to voluntarily suppress and inhibit the multimodal rightward spatial bias changes as a function of age and praxis due to sensory deficit and probably reflects the developmental level of executive functions.

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Rajavartiolaitos on yhteiskunnallisesti merkittävä turvallisuusviranomainen. Erityisesti laitoksen merellinen rooli sisäisen turvallisuuden kentässä on korostunut sen lakisääteisten merellisten tehtävien ansiosta. Rajavartiolaitoksen merelliselle roolille onkin asetettu huomattavat tavoitteet viraston strategia-asiakirjassa. Rajavartiolaitoksen strategian toimeenpanoa tai siinä suoriutumista ei tieteellisen tutkimuksen keinoin ole aiemmin tutkittu. Tutkimuksen tarkoituksena oli muodostaa rajavartiolaitoksen strategian toimeenpanon tutkimusta tukeva teoreettinen viitekehys. Näkökulma viitekehyksen muodostamiseksi oli merellinen. Kyseisen viitekehyksen avulla mahdollistetaan strategian toimeenpanossa onnistumisen tutkiminen nimenomaisesti merellisestä perspektiivistä. Tutkittaessa toimeenpanoon liittyvien tekijöiden toteutumista tai ilmentymiä rajavartiolaitoksen implementaatioprosessissa voidaan päätyä myös arvioon sen yhteiskunnallisesta vaikuttavuudesta ja viimekädessä roolista. Jatkotutkimuksen tehtävä on varsinainen implementaation tutkiminen nyt muodostettua teoreettista viitekehystä hyödyntäen. Implementaation tutkimuskenttään liittyy useita erilaisia teoreettisia suuntauksia. Teorialähtöisen sisällönanalyysin avulla pyrittiin muodostamaan kattava kuva vallitsevista teorioista varsinaisen paradigman puuttuessa. Sisällönanalyysin analyysirungoksi valittiin topdown- teorian käsitemaailma. Analysoitavat teokset valittiin implementaatiotutkimuksen vahvinta perinnettä edustavien tutkimusjulkaisujen ja artikkeleiden joukosta pyrkimyksenä huomioimaan tutkimuksen alan valtavirtaan kuuluvat merkittävimmät lähestymistavat. Rajavartiolaitoksen strategian toimeenpanon tutkimusta tukevan teorian muodostamiseksi tuli sisällönanalyysistä kumpuavat teoriat sitoa soveltuvin osin reaalimaailmaan eli viraston prosesseihin ja toimintaympäristöön. Tätä varten muodostettiin käsitys rajavartiolaitoksen strategisesta olosuhdeympäristöstä sekä sidottiin toimeenpanon prosessit governanssin teoriaan käyttäen Multiple Govenance Framework -viitekehystä (MGF). Varsinainen viitekehys ja siihen liittyvät tekijät valittiin analysoidusta materiaalista tukeutuen abduktiiviseen päättelyyn. Tutkimuksen johtopäätöksenä voidaan todeta rajavartiolaitoksen edustavan tietyssä määrin top-down-tutkimusperinteeseen liittyviä piirteitä. Tämä teoria ei kuitenkaan kaikilta osin huomio niitä erityispiirteitä, jotka tutkimuksessa tunnistettiin. Yhdistämällä MGF:n ominaisuudet ja top-down-teoriasta soveltuvat tekijät, muodostettiin hypoteesi rajavartiolaitoksen implementaatiota tukevasta viitekehyksestä. Viitekehys sidottiin rajavartiolaitokseen, mutta varsinainen operationalisointi jätettiin jatkotutkimuksen tehtäväksi.

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Tutkielman aiheena on tuloskortin kritiikki ja sen analysointi kontingenssiteorian näkökulmasta. Tutkimuksen kohdeyrityksen tuloskortin kritiikkiä on verrattu laskentatoimen tieteellisessä keskustelussa esitettyyn kritiikkiin. Tuloskortin kritiikin ja kontingenssiteorian näkökulmien perusteella tutkimuksen kohdeyrityksen suorituskyvyn mittaamisen kehittämiskohteita on tunnistettu. Tutkimuksen kohdeyritys on suomalainen korkean teknologian yritys, joka on osa yhdysvaltalaista globaalia konsernia. Tutkimuksen teoreettinen tausta perustuu kontingenssiteoriaan ja tuloskortin ja suorituskyvyn mittaamisen doktriiniin. Tutkimus on luonteeltaan toimintaanalyyttinen. Tutkimusaineisto koostuu tieteellisistä artikkeleista, kirjallisuudesta ja kohdeyrityksessä suoritetuista teemahaastatteluista. Tutkielman teoriaosa alkaa Balanced Scorecardin ja muiden tuloskorttien esittelyllä ja vertailulla. Kontingenssiteorian käsittely perustuu tieteellisessä kirjallisuudessa yleisiin tilannetekijöihin: ulkoinen ympäristö, teknologia, strategia ja organisaatiorakenne. Muista tilannetekijöistä käsiteltiin kulttuuripiiri, joka on relevantti tutkimuksen kohdeyrityksen tarkastelussa. Teoreettisen osan selkärangan muodostaa tuloskortin kritiikin analysointi, joka on jaettu Balanced Scorecardin kritiikkiin ja yleiseen tuloskortin kritiikkiin. Kritiikin sisältöä on tulkittu myös kontingenssiteorian avulla. Tutkimuksen kohdeyritys käyttää kolmea erilaista tuloskorttimallia. Tuloskortin kritiikki kohdeyrityksessä vastaa pääosin tieteellisessä keskustelussa esitettyä kritiikkiä. Tuloskortin näkökulmien väliset suhteet, liityntä strategiaan, puutteellinen ajallinen ulottuvuus ja rooli top-down –johtamismallin työkaluna olivat yleisimmät kritiikin kohteet. Kohdeyrityksessä esille nousivat myös tutkimuksen ja tuotekehityksen mittaamisen haasteellisuus, organisaation funktionaaliset rajaaidat, yhdysvaltalainen toiminnanohjaamisen malli ja kohdeyrityksen rooli osana globaalia konsernia. Kontingenssitekijöistä kritiikkiä eniten selittävät ulkoinen ympäristö, organisaatiorakenne ja kulttuuripiiri. Tutkimuksen kohdeyrityksessä tuloskortin kehittämistarpeet kohdistuvat organisaatiorakenteen muokkaamiseen, tuloskortin tavoitteiden viestintään henkilöstölle, tietoteknisiin ratkaisuihin ja konsernin osana toimimiseen. Kontingenssitekijöiden huomioiminen antaa tutkimuksen perusteella hyvän lähtökohdan tuloskortin ja yleisesti suorituskyvyn mittaamisen kehittämiselle yrityksissä.

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Prerequisites and effects of proactive and preventive psycho-social student welfare activities in Finnish preschool and elementary school were of interest in the present thesis. So far, Finnish student welfare work has mainly focused on interventions and individuals, and the voluminous possibilities to enhance well-being of all students as a part of everyday school work have not been fully exploited. Consequently, in this thesis three goals were set: (1) To present concrete examples of proactive and preventive psycho-social student welfare activities in Finnish basic education; (2) To investigate measurable positive effects of proactive and preventive activities; and (3) To investigate implementation of proactive and preventive activities in ecological contexts. Two prominent phenomena in preschool and elementary school years—transition to formal schooling and school bullying—were chosen as examples of critical situations that are appropriate targets for proactive and preventive psycho-social student welfare activities. Until lately, the procedures concerning both school transitions and school bullying have been rather problem-focused and reactive in nature. Theoretically, we lean on the bioecological model of development by Bronfenbrenner and Morris with concentric micro-, meso-, exo- and macrosystems. Data were drawn from two large-scale research projects, the longitudinal First Steps Study: Interactive Learning in the Child–Parent– Teacher Triangle, and the Evaluation Study of the National Antibullying Program KiVa. In Study I, we found that the academic skills of children from preschool–elementary school pairs that implemented several supportive activities during the preschool year developed more quickly from preschool to Grade 1 compared with the skills of children from pairs that used fewer practices. In Study II, we focused on possible effects of proactive and preventive actions on teachers and found that participation in the KiVa antibullying program influenced teachers‘ self-evaluated competence to tackle bullying. In Studies III and IV, we investigated factors that affect implementation rate of these proactive and preventive actions. In Study III, we found that principal‘s commitment and support for antibullying work has a clear-cut positive effect on implementation adherence of student lessons of the KiVa antibullying program. The more teachers experience support for and commitment to anti-bullying work from their principal, the more they report having covered KiVa student lessons and topics. In Study IV, we wanted to find out why some schools implement several useful and inexpensive transition practices, whereas other schools use only a few of them. We were interested in broadening the scope and looking at local-level (exosystem) qualities, and, in fact, the local-level activities and guidelines, along with teacherreported importance of the transition practices, were the only factors significantly associated with the implementation rate of transition practices between elementary schools and partner preschools. Teacher- and school-level factors available in this study turned out to be mostly not significant. To summarize, the results confirm that school-based promotion and prevention activities may have beneficial effects not only on students but also on teachers. Second, various top-down processes, such as engagement at the level of elementary school principals or local administration may enhance implementation of these beneficial activities. The main message is that when aiming to support the lives of children the primary focus should be on adults. In future, promotion of psychosocial well-being and the intrinsic value of inter- and intrapersonal skills need to be strengthened in the Finnish educational systems. Future research efforts in student welfare and school psychology, as well as focused training for psychologists in educational contexts, should be encouraged in the departments of psychology and education in Finnish universities. Moreover, a specific research centre for school health and well-being should be established.

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Companies today are forced to innovate in order to remain within business. Such innovation projects undertaken by the companies are defined in this study as creative ideas which have been managed through “Stage-Gate” innovation process. This process is used to manage innovation projects as they proceed from being newly created to ready for launching/implementing. This has ensured that the companies manage the innovation project right. However, with so many new creative ideas the companies can come up within limited resources, the companies must rely on Innovation Project Portfolio Management (IPPM) to ensure that they are managing only the right innovation projects. Although, there are many tools and techniques available for use within Project Portfolio Management, there is still no consensus on which are the most effective and no standard framework has been established especially for IPPM. Thus, this study proposes a practical framework for which individual innovative organization can follow as a guideline to manage its innovation project portfolio. The study theoretically first addresses the key differences between project portfolio management of innovation projects and other traditional projects - one of which is the stage nature of innovation projects due to their unclear objectives from the beginning compare to clearly established objectives of traditional projects. Secondly, different tools and techniques which can be used are examined based on the three goals of IPPM: (1) Maximizing the Value of Innovation Project Portfolio: Financial Methods, Decision Trees, Scoring Models and Checklists; (2) Balancing Innovation Project Portfolio: Visual Representations; and (3) Aligning Innovation Project Portfolio with Strategy: Bottom-Up (Scoring Models with Strategic Criteria) and Top-Down (Strategic Buckets). Finally, the two approaches in which IPPM can be integrated with Stage-Gate innovation process are discussed: (1) Gates- Dominated; and (2) Portfolio Reviews-Dominated. Practically, this study investigates IPPM of a case organization, and through analysis of the case study results proposes a practical framework for case organization to improve its current management of innovation project portfolio. This framework is then generalized to propose a final practical framework or guideline for which an innovative organization can follow to manage its innovation project portfolio.

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One of the greatest conundrums to the contemporary science is the relation between consciousness and brain activity, and one of the specifi c questions is how neural activity can generate vivid subjective experiences. Studies focusing on visual consciousness have become essential in solving the empirical questions of consciousness. Th e main aim of this thesis is to clarify the relation between visual consciousness and the neural and electrophysiological processes of the brain. By applying electroencephalography and functional magnetic resonance image-guided transcranial magnetic stimulation (TMS), we investigated the links between conscious perception and attention, the temporal evolution of visual consciousness during stimulus processing, the causal roles of primary visual cortex (V1), visual area 2 (V2) and lateral occipital cortex (LO) in the generation of visual consciousness and also the methodological issues concerning the accuracy of targeting TMS to V1. Th e results showed that the fi rst eff ects of visual consciousness on electrophysiological responses (about 140 ms aft er the stimulus-onset) appeared earlier than the eff ects of selective attention, and also in the unattended condition, suggesting that visual consciousness and selective attention are two independent phenomena which have distinct underlying neural mechanisms. In addition, while it is well known that V1 is necessary for visual awareness, the results of the present thesis suggest that also the abutting visual area V2 is a prerequisite for conscious perception. In our studies, the activation in V2 was necessary for the conscious perception of change in contrast for a shorter period of time than in the case of more detailed conscious perception. We also found that TMS in LO suppressed the conscious perception of object shape when TMS was delivered in two distinct time windows, the latter corresponding with the timing of the ERPs related to the conscious perception of coherent object shape. Th e result supports the view that LO is crucial in conscious perception of object coherency and is likely to be directly involved in the generation of visual consciousness. Furthermore, we found that visual sensations, or phosphenes, elicited by the TMS of V1 were brighter than identically induced phosphenes arising from V2. Th ese fi ndings demonstrate that V1 contributes more to the generation of the sensation of brightness than does V2. Th e results also suggest that top-down activation from V2 to V1 is probably associated with phosphene generation. The results of the methodological study imply that when a commonly used landmark (2 cm above the inion) is used in targeting TMS to V1, the TMS-induced electric fi eld is likely to be highest in dorsal V2. When V1 was targeted according to the individual retinotopic data, the electric fi eld was highest in V1 only in half of the participants. Th is result suggests that if the objective is to study the role of V1 with TMS methodology, at least functional maps of V1 and V2 should be applied with computational model of the TMS-induced electric fi eld in V1 and V2. Finally, the results of this thesis imply that diff erent features of attention contribute diff erently to visual consciousness, and thus, the theoretical model which is built up of the relationship between visual consciousness and attention should acknowledge these diff erences. Future studies should also explore the possibility that visual consciousness consists of several processing stages, each of which have their distinct underlying neural mechanisms.

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Graphene is a material with extraordinary properties. Its mechanical and electrical properties are unparalleled but the difficulties in its production are hindering its breakthrough in on applications. Graphene is a two-dimensional material made entirely of carbon atoms and it is only a single atom thick. In this work, properties of graphene and graphene based materials are described, together with their common preparation techniques and related challenges. This Thesis concentrates on the topdown techniques, in which natural graphite is used as a precursor for the graphene production. Graphite consists of graphene sheets, which are stacked together tightly. In the top-down techniques various physical or chemical routes are used to overcome the forces keeping the graphene sheets together, and many of them are described in the Thesis. The most common chemical method is the oxidisation of graphite with strong oxidants, which creates a water-soluble graphene oxide. The properties of graphene oxide differ significantly from pristine graphene and, therefore, graphene oxide is often reduced to form materials collectively known as reduced graphene oxide. In the experimental part, the main focus is on the chemical and electrochemical reduction of graphene oxide. A novel chemical route using vanadium is introduced and compared to other common chemical graphene oxide reduction methods. A strong emphasis is placed on electrochemical reduction of graphene oxide in various solvents. Raman and infrared spectroscopy are both used in in situ spectroelectrochemistry to closely monitor the spectral changes during the reduction process. These in situ techniques allow the precise control over the reduction process and even small changes in the material can be detected. Graphene and few layer graphene were also prepared using a physical force to separate these materials from graphite. Special adsorbate molecules in aqueous solutions, together with sonic treatment, produce stable dispersions of graphene and few layer graphene sheets in water. This mechanical exfoliation method damages the graphene sheets considerable less than the chemical methods, although it suffers from a lower yield.

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Diplomityön tavoitteena on tutkia valmistusstrategian muodostamista rajaten tarkastelu yhteen tuoteperheeseen. Työn teoriaosuudessa suoritaan kirjallisuuskatsaus, jonka keskeisempänä tuloksena luodaan teoriaviitekehys valmistusstrategian muodostamisesta. Valmistusstrategian osa-alueiksi rajataan toimitusketjun rakenne, tuotantomuodon valinta, kapasiteetin suunnittelu sekä materiaalinohjaus. Työn soveltavassa osuudessa muodostetaan esitetyn teoriaviitekehyksen avulla valmistusstrategiaehdotelma Case – yrityksen uudelle tuoteperheelle. Valmistusstrategian tavoitteet sekä rajoitteet tunnistetaan tarkastelemalla yrityksen ylemmän tason strategioita, markkinavaatimuksia, valmistuksen resursseja sekä päivittäistä toimintaa. Kokonaisuudessaan diplomityö käsittelee valmistusstrategian muodostamista aikaisempaa kirjallisuutta yksityiskohtaisemmin ja käytännönläheisemmästä näkökulmasta. Case – yrityksen uudelle tuoteperheelle ehdotettu valmistusstrategia todetaan seuraavan yleisesti hyviä toimitusketjun johtamisen periaatteita.

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In marine benthic communities, herbivores consume a considerable proportion of primary producer biomass and, thus, generate selection for the evolution of resistance traits. According to the theory of plant defenses, resistance traits are costly to produce and, consequently, inducible resistance traits are adaptive in conditions of variable herbivory, while in conditions of constant/strong herbivory constitutive resistance traits are selected for. The evolution of resistance plasticity may be constrained by the costs of resistance or lack of genetic variation in resistance. Furthermore, resource allocation to induced resistance may be affected by higher trophic levels preying on herbivores. I studied the resistance to herbivory of a foundation species, the brown alga Fucus vesiculosus. By using factorial field experiments, I explored the effects of herbivores and fish predators on growth and resistance of the alga in two seasons. I explored genetic variation in and allocation costs of resistance traits as well as their chemical basis and their effects on herbivore performance. Using a field experiment I tested if induced resistance spreads via water-borne cues from one individual to another in relevant ecological conditions. I found that in the northern Baltic Sea F. vesiculosus communities, strength of three trophic interactions strongly vary among seasons. The highly synchronized summer reproduction of herbivores promoted their escape from the top-down control of fish predators in autumn. This resulted into large grazing losses in algal stands. In spring, herbivore densities were low and regulated by fish, which, thus,enhanced algal growth. The resistance of algae to herbivory increased with an increase in constitutive phlorotannin content. Furthermore, individuals adopted induced resistance when grazed and when exposed to water-borne cues originating from grazing of conspecific algae both in the laboratory and in field conditions. Induced resistance was adopted to a lesser extent in the presence of fish predators. The results in this thesis indicate that inducible resistance in F. vesiculosus is an adaptation to varying herbivory in the northern Baltic Sea. The costs of resistance and strong seasonality of herbivory have likely contributed to the evolution of this defense strategy. My findings also show that fish predators have positive cascading effects on F. vesiculosus which arise via reduced herbivory but possibly also through reduced resource allocation to resistance. I further found evidence that the spread of resistance via water-borne cues also occurs in ecologically realistic conditions in natural marine sublittoral. Thus, water-borne induction may enable macroalgae to cope with the strong grazing pressure characteristic of marine benthic communities. The results presented here show that seasonality can have pronounced effects on the biotic interactions in marine benthic communities and thereafter influence the evolution of resistance traits in primary producers.

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Lisääntynyt Balanced Scorecardin käyttö herätti kiinnostuksen tutkia, mistä BSC:ssä oli oikein kysymys. Epäonnistumiset BSC-projekteissa vaikuttivat siihen, että haluttiin tutkia, mikä nykyisissä projektimalleissa oli vikana. Kirjallisuudessa on esitetty useita BSC:n käyttöönoton projektimalleja, joista tunnetuin on Kaplanin ja Nortonin kehittämä malli. Alun perin kyseessä oli varsin operatiivinen suoritusmittaristo, jonka tavoitteena oli nostaa ei-taloudelliset mittarit taloudellisten mittareiden rinnalle. Sittemmin lähestymistapa onlaajentunut strategiapohjaiseksi johtamisen järjestelmäksi, mutta mallin rakentamisessa on vielä puutteita. Havaitut puutteet BSC-projektimalleissa loivat tarpeen uuden mallin kehittämiselle. Tutkimuksen tavoitteena oli kehittää suomalaisten yritysjohtajien ja alan asiantuntijoiden avulla BSC-projektimalli, jota käyttämällä yritykset voisivat menestyksekkäämmin toteuttaa BSC-projektinsa. Lisäksi tavoitteena oli selvittää BSC:n käytön nykytila Suomen 500 suurimmassa yrityksessä. Tutkimuksessa haluttiin myös hankkia tietoa siitä, miksi yritykset olivat lähteneet BSC-projektiin, mitkä tekijät vaikuttivat BSC-projektin onnistumiseen jamitä muutoksia yritykset olivat tehneet BSC:n käytännön kokemuksen pohjalta. Tutkimuksen teoriaosassa tarkasteltiin yrityksen strategista suunnittelua ja johtamista, yrityksen johtamisessa käytettyjä ohjausjärjestelmiä, toiminnan kehittämistä ja BSC-projektien toteuttamista. Tutkimuksen empiriisessä osassa kehitettiinkymmenvaiheinen BSC-projektin toteuttamismalli. Se tehtiin tutustumalla 15 konsultointiyrityksen tapaan toteuttaa BSC-projekti ja paneutumalla 50 yrityksen BSC-projektista saamiin kokemuksiin. Kehitettyä mallia testattiin Tulikivi-casessa,ja sitä arvioitiin kyselytutkimuksessa ja työistunnossa. Kyselytutkimuksen mukaan ensimmäiset suomalaiset yritykset aloittivat BSC:n käytön vuonna 1995. Vuonna1996 käyttö yleistyi jonkin verran, ja vuosia 1997 ja 1998 voidaan Suomessa kutsua BSC:n läpimurtovuosiksi. Vastanneista yrityksistä 23,2 % ilmoitti käyttävänsä BSC:tä. Yrityksistä 14,8 % oli ottamassa sitä käyttöön, ja 19,2 % harkitsi käyttöönottamista. Yritykset olivat lähteneet BSC-projektiin mm. paremman ohjausjärjestelmän, toiminnan tehostamisen ja muutoksen aikaansaamisen toivossa. BSC-projektin onnistumisen tärkeimpinä tekijöinä pidettiin johdon sitoutumista hankkeeseen, mittariston kytkeytymistä strategiaan ja mittareiden selkeyttä. BSC:n nähtiin vaikuttaneen yrityksissä eniten liiketoiminnan kokonaisuuden ymmärtämiseen, strategian toteutumiseen ja ei-taloudellisten asioiden seurantaan. Yrityksissä olimuutettu toimintaa mm. niin, että se suuntautuisi enemmän asiakkaisiin ja tulevaisuuteen. Tulevaisuudessa BSC:llä uskottiin olevan suurimmat vaikutukset kokonaisvaltaiseen ja strategiseen johtamiseen sekä strategian toteutumisen seurantaan. Kyselytutkimuksen perusteella voitiin osoittaa, että suuret yritykset käyttävät BSC:tä enemmän kuin pienet yritykset. Myös alueellisia eroja on: pääkaupunkiseudulla BSC:tä käytetään enemmän kuin muualla maassa. Mitä kannattavammaksi kyselyyn vastaaja arvioi yrityksensä, sitä parempana se piti tässä tutkimuksessa kehitettyä BSC-projektimallia verrattuna Kaplanin ja Nortonin kehittämään BSC-projektimalliin. BSC-projekti on niin kokonaisvaltainen, että sen onnistuminen edellyttää koko henkilöstön osallistuvan siihen. Ylimmän johdon aito sitoutuminen on välttämätöntä, jotta BSC-projekti saa riittävästi resursseja. Projektissa visio jastrategiat puretaan käytännön toimiksi, joten ilman ylimmän johdon mukanaoloa projektilla ei ole asiakasta. Keskijohto ja henkilöstö toteuttavat laaditut strategiat, jolloin heidän panoksensa on erittäin merkittävä projektin onnistumiseksi. Henkilöstö pitää saada osallistumaan mittaristotyöhön, jotta he sitoutuisivat asetettuihin tavoitteisiin. Ellei henkilöstöä saada mukaan, mittaristo jää helposti ylimmän johdon työkaluksi. Tällöin strategian toteuttaminen koko organisaatiossa on hyvin työlästä, jopa mahdotonta. Mittariston pitää olla strategialähtöinen, eikä se saa olla liian monimutkainen. Mitä alemmalle tasolle organisaatiossamennään, sitä yksinkertaisempi mittariston pitää olla. Ylimmillä tasoilla mittareita voi olla kahdeksasta kahteentoista, mutta alemmilla tasoilla niitä on oltava hieman vähemmän. Projektin nopea läpivienti yrityksessä ei saa olla itsetarkoitus, mutta nopeasti saadut konkreettiset tulokset auttavat, että projekti saa resursseja ja mahdollistavat palautteen saamisen ja oppimisen. Kerralla ei BSC:täsaada täydellisesti toimivaksi, vaan se on oppimisprosessi, joka mahdollistaa syvällisemmän strategian toteuttamiseen. Tässä tutkimuksessa kehitetty BSC-projektin toteuttamismalli perustuu kymmenien asiantuntijoiden kokemuksiin ja näkemyksiin BSC-projektin toteuttamisesta. Kyselytutkimuksesta, työistunnosta ja Tulikivi-casesta saadut tulokset osoittavat, että kehitetyn mallin avulla yrityksillä on entistä paremmat mahdollisuudet saada BSC-projekti onnistumaan. Näin tutkimuksen päätavoite saavutettiin. Muut tavoitteet saavutettiin kyselytutkimuksen tulosten avulla.

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Tämän tutkielman tavoitteena oli määrittää uuden markkinan valinnan perusteita teolliselle tuotteelle. Tutkielma keskittyi jo tunnettuihin kansainvälisen markkinavalinnan lähestymistapoihin ja pyrki soveltamaan yhtä menetelmää käytäntöön tutkielman empiria osassa case-tutkimuksen avulla. Tutkimusote oli tutkiva, eksploratiivinen ja perustui sekundääri analyysiin. Käytetyt tiedon lähteet olivat suureksi osin sekundäärisiä tuottaen kvalitatiivista tietoa. Kuitenkin haastatteluita suoritettiin myös. Kattava kirjallisuus katsaus tunnetuista teoreettisista lähestymistavoista kansainväliseen markkinavalintaan oli osa tutkielmaa. Kolme tärkeintä lähestymistapaa esiteltiin tarkemmin. Yksi lähestymistavoista, ei-järjestelmällinen, muodosti viitekehyksen tutkielman empiria-osalle. Empiria pyrki soveltamaan yhtä ei-järjestelmällisen lähestymistavan malleista kansainvälisessä paperiteollisuudessa. Tarkoituksena oli tunnistaa kaikkein houkuttelevimmat maat mahdollisille markkinointitoimenpiteille tuotteen yhdellä loppukäyttöalueella. Tutkielmassa päädyttiin käyttämään ilmastollisia olosuhteita, siipikarjan päälukua sekä siipikarjan kasvuprosenttia suodattimina pyrittäessä vähentämään mahdollisten maiden lukumäärää. Tutkielman empiria-osa kärsi selkeästi relevantin tiedon puutteesta. Siten myös tutkielman reliabiliteetti ja validiteetti voidaan jossain määrin kyseenalaistaa.

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Social networking and social networking sites have gained popularity among internet users during the past few years. Social networks fulfill the need of users to stay connected to friends and other people interested in the same issues. Combining social networks to the mobile environment is a growing interest of mobile device users as it allows the users to be in their online social community despite their mobility. This thesis highlights the basics of mobile environment, social networking and PeerHood and introduces a new approach of social networking on mobile environment, which is a new concept in mobile social networking. This approach is based on dynamic group discovery in accordance to some common user interests and management in the PeerHood environment. A reference implementation of a social networking application built on top of PeerHood is presented and it is tested and analyzed to understand the social networking on mobile environment and the new concept of dynamic group discovery in it.