50 resultados para Braking In a Turn.
Resumo:
The aim of the study is to find out “What are the challenges to overcome for the successful nanotechnology commercialization in Russia?” Working closely with the case country was definitely an advantage when it comes to the understanding of the research subject. The thesis is divided to two parts: first part examines the concept of technology commercialization and identifies unique aspects of the process in context of nanotechnology. Second part is dedicated to an empirical research, investigating current status of nanotechnology commercialization in Russia. For the purpose of this study, Russian and international scientists, researchers, entrepreneurs, industry and government representatives were interviewed systematically during 2007 – 2009. Based on the research done it can be concluded that immense public funding provides necessary support for the development of Russian nanotechnology industry. However, investments alone do not address important structural shortcomings of a national innovation system, which in turn slow down the progress. Taking into consideration gap between science and business and challenging IPR legislation, expected significant economic impact in Russia may be overestimated. Nevertheless it should be noted that development of nanotechnology is advancing rapidly and therefore, the state of commercialization is changing accordingly, even while this lines are written.
Resumo:
The growth of breast cancer is regulated by hormones and growth factors. Recently, aberrant fibroblast growth factor (FGF) signalling has been strongly implicated in promoting the progression of breast cancer and is thought to have a role in the development of endocrine resistant disease. FGFs mediate their auto- and paracrine signals through binding to FGF receptors 1-4 (FGFR1-4) and their isoforms. Specific targets of FGFs in breast cancer cells and the differential role of FGFRs, however, are poorly described. FGF-8 is expressed at elevated levels in breast cancer, and it has been shown to act as an angiogenic, growth promoting factor in experimental models of breast cancer. Furthermore, it plays an important role in mediating androgen effects in prostate cancer and in some breast cancer cell lines. We aimed to study testosterone (Te) and FGF-8 regulated genes in Shionogi 115 (S115) breast cancer cells, characterise FGF-8 activated intracellular signalling pathways and clarify the role of FGFR1, -2 and -3 in these cells. Thrombospondin-1 (TSP-1), an endogenous inhibitor of angiogenesis, was recognised as a Te and FGF-8 regulated gene. Te repression of TSP-1 was androgen receptor (AR)-dependent. It required de novo protein synthesis, but it was independent of FGF-8 expression. FGF-8, in turn, downregulated TSP-1 transcription by activating the ERK and PI3K pathways, and the effect could be reversed by specific kinase inhibitors. Differential FGFR1-3 action was studied by silencing each receptor by shRNA expression in S115 cells. FGFR1 expression was a prerequisite for the growth of S115 tumours, whereas FGFR2 expression alone was not able to promote tumour growth. High FGFR1 expression led to a growth advantage that was associated with strong ERK activation, increased angiogenesis and reduced apoptosis, and all of these effects could be reversed by an FGFR inhibitor. Taken together, the results of this thesis show that FGF-8 and FGFRs contribute strongly to the regulation of the growth and angiogenesis of experimental breast cancer and support the evidence for FGF-FGFR signalling as one of the major players in breast cancers.
Resumo:
The overall goal of this study was to support evidence based clinical nursing regarding patient seclusion and restraint practices. This was done by ensuring professional competence through innovative learning methods. The data were collected in three phases between March 2007 and May 2009 on acute psychiatric wards. Firstly, psychiatric inpatients’ experiences and suggestions for seclusion and restraint practices were explored (n=30). Secondly, nursing and medical personnel’s perceptions of seclusion and restraint practices were explored (n=27). Thirdly, the impacts of a continuing vocational eLearning course on nurses’ professional competence was evaluated (n=158). Patients’ perspectives received insufficient attention during the seclusion and restraint process. Improvements and alternatives to seclusion and restraint as suggested by the patients focused on essential parts of clinical nursing, but were not extensively adopted. Also nursing and medical personnel thought that patients’ subjective perspective received little attention. Personnel proposed a number of alternatives to seclusion and restraint, and they expressed a need for education and support to adopt these in clinical nursing. Evaluation of impacts of eLearning course on nurses’ professional competence showed no statistical differences between an eLearning group and an education-as-usual group. This dissertation provides evidence based knowledge about the realization of seclusion and restraint practices and the impacts of eLearning course on nurses’ professional competence in psychiatric hospitals. In order to improve clinical nursing the patient perspective must be accentuated. To ensure personnel’s professional competence, there is a need for written clinical guidelines, education and support. Continuing vocational education should bring together written clinical guidelines, ethical and legal issues and the support for personnel. To achieve the ambitious goal of such integration, achievable and affordable educational programmes are required. This, in turn, yields a call for innovative learning methods.
Resumo:
Adequate supply of oxygen is essential for the survival of multicellular organisms. However, in several conditions the supply of oxygen can be disturbed and the tissue oxygenation is compromised. This condition is termed hypoxia. Oxygen homeostasis is maintained by the regulation of both the use and delivery of oxygen through complex, sensitive and cell-type specific transcriptional responses to hypoxia. This is mainly achieved by one master regulator, a transcription factor called hypoxiainducible factor 1 (HIF-1). The amount of HIF-1 is under tight oxygen-dependent control by a family of oxygen-dependent prolyl hydroxylase domain proteins (PHDs) that function as the cellular oxygen sensors. Three family members (PHD1-3) are known to regulate HIF of which the PHD2 isoform is thought to be the main regulator of HIF-1. The supply of oxygen can be disturbed in pathophysiological conditions, such as ischemic disorders and cancer. Cancer cells in the hypoxic parts of the tumors exploit the ability of HIF-1 to turn on the mechanisms for their survival, resistance to treatment, and escape from the oxygen- and nutrient-deprived environment. In this study, the expression and regulation of PHD2 were studied in normal and cancerous tissues, and its significance in tumor growth. The results show that the expression of PHD2 is induced in hypoxic cells. It is overexpressed in head and neck squamous cell carcinomas and colon adenocarcinomas. Although PHD2 normally resides in the cytoplasm, nuclear translocation of PHD2 was also seen in a subset of tumor cells. Together with the overexpression, the nuclear localization correlated with the aggressiveness of the tumors. The nuclear localization of PHD2 caused an increase in the anchorage-independent growth of cancer cells. This study provides information on the role of PHD2, the main regulator of HIF expression, in cancer progression. This knowledge may prove to be valuable in targeting the HIF pathway in cancer treatment.
Knowledge Sharing between Generations in an Organisation - Retention of the Old or Building the New?
Resumo:
The study explores knowledge transfer between retiring employees and their successors in expert work. My aim is to ascertain whether there is knowledge development or building new knowledge related to this organisational knowledge transfer between generations; in other words, is the transfer of knowledge from experienced, retiring employees to their successors merely retention of the existing organisational knowledge by distributing it from one individual to another or does this transfer lead to building new and meaningful organisational knowledge. I call knowledge transfer between generations and the possibly related knowledge building in this study knowledge sharing between generations. The study examines the organisation and knowledge management from a knowledge-based and constructionist view. From this standpoint, I see knowledge transfer as an interactive process, and the exploration is based on how the people involved in this process understand and experience the phenomenon studied. The research method is organisational ethnography. I conducted the analysis of data using thematic analysis and the articulation method, which has not been used before in organisational knowledge studies. The primary empirical data consists of theme interviews with twelve employees involved in knowledge transfer in the organisation being studied and five follow-up theme interviews. Six of the interviewees are expert duty employees due to retire shortly, and six are their successors. All those participating in the follow-up interviews are successors of those soon to retire from their expert responsibilities. The organisation in the study is a medium-sized Finnish firm, which designs and manufactures electrical equipment and systems for the global market. The results of the study show that expert work-related knowledge transfer between generations can mean knowledge building which produces new, meaningful knowledge for the organisation. This knowledge is distributed in the organisation to all those that find it useful in increasing the efficiency and competitiveness of the whole organisation. The transfer and building of knowledge together create an act of knowledge sharing between generations where the building of knowledge presupposes transfer. Knowledge sharing proceeds between the expert and the novice through eight phases. During the phases of knowledge transfer the expert guides the novice to absorb the knowledge to be transferred. With the expert’s help the novice gradually comes to understand the knowledge and in the end he or she is capable of using it in his or her work. During the phases of knowledge building the expert helps the novice to further develop the knowledge being transferred so that it becomes new, useful knowledge for the organisation. After that the novice takes the built knowledge to use in his or her work. Based on the results of the study, knowledge sharing between generations takes place in interaction and ends when knowledge is taken to use. The results I obtained in the interviews by the articulation method show that knowledge sharing between generations is shaped by the novices’ conceptions of their own work goals, knowledge needs and duties. These are not only based on the official definition of the work, but also how the novices find their work or how they prioritise the given objectives and responsibilities. The study shows that the novices see their work primarily as maintenance or development. Those primarily involved in maintenance duties do not necessarily need knowledge defined as transferred between generations. Therefore, they do not necessarily transfer knowledge with their assigned experts, even though this can happen in favourable circumstances. They do not build knowledge because their view of their work goals and duties does not require the building of new knowledge. Those primarily involved in development duties, however, do need knowledge available from their assigned experts. Therefore, regardless of circumstances they transfer knowledge with their assigned experts and also build knowledge because their work goals and duties create a basis for building new knowledge. The literature on knowledge transfer between generations has focused on describing either the knowledge being transferred or the means by which it is transferred. Based on the results of this study, however, knowledge sharing between generations, that is, transfer and building is determined by how the novice considers his or her own knowledge needs and work practices. This is why studies on knowledge sharing between generations and its implementation should be based not only on the knowledge content and how it is shared, but also on the context of the work in which the novice interprets and shares knowledge. The existing literature has not considered the possibility that knowledge transfer between generations may mean building knowledge. The results of this study, however, show that this is possible. In knowledge building, the expert’s existing organisational knowledge is combined with the new knowledge that the novice brings to the organisation. In their interaction this combination of the expert’s “old” and the novice’s “new” knowledge becomes new, meaningful organisational knowledge. Previous studies show that knowledge development between the members of an organisation is the prerequisite for organisational renewal which in turn is essential for improved competitiveness. Against this background, knowledge building enables organisational renewal and thus enhances competitiveness. Hence, when knowledge transfer between generations is followed by knowledge building, the organisation kills two birds with one stone. In knowledge transfer the organisation retains the existing knowledge and thus maintains its competitiveness. In knowledge building the organisation developsnew knowledge and thus improves its competitiveness.
Resumo:
The use of domain-specific languages (DSLs) has been proposed as an approach to cost-e ectively develop families of software systems in a restricted application domain. Domain-specific languages in combination with the accumulated knowledge and experience of previous implementations, can in turn be used to generate new applications with unique sets of requirements. For this reason, DSLs are considered to be an important approach for software reuse. However, the toolset supporting a particular domain-specific language is also domain-specific and is per definition not reusable. Therefore, creating and maintaining a DSL requires additional resources that could be even larger than the savings associated with using them. As a solution, di erent tool frameworks have been proposed to simplify and reduce the cost of developments of DSLs. Developers of tool support for DSLs need to instantiate, customize or configure the framework for a particular DSL. There are di erent approaches for this. An approach is to use an application programming interface (API) and to extend the basic framework using an imperative programming language. An example of a tools which is based on this approach is Eclipse GEF. Another approach is to configure the framework using declarative languages that are independent of the underlying framework implementation. We believe this second approach can bring important benefits as this brings focus to specifying what should the tool be like instead of writing a program specifying how the tool achieves this functionality. In this thesis we explore this second approach. We use graph transformation as the basic approach to customize a domain-specific modeling (DSM) tool framework. The contributions of this thesis includes a comparison of di erent approaches for defining, representing and interchanging software modeling languages and models and a tool architecture for an open domain-specific modeling framework that e ciently integrates several model transformation components and visual editors. We also present several specific algorithms and tool components for DSM framework. These include an approach for graph query based on region operators and the star operator and an approach for reconciling models and diagrams after executing model transformation programs. We exemplify our approach with two case studies MICAS and EFCO. In these studies we show how our experimental modeling tool framework has been used to define tool environments for domain-specific languages.
Resumo:
The purpose of this thesis is to study organizational core values and their application in practice. With the help of literature, the thesis discusses the implementation of core values and the benefits that companies can gain by doing it successfully. Also, ways in which companies can improve their values’ application to their everyday work are presented. The case company’s value implementation is evaluated through a survey research conducted on their employees. The true power of values lies in their application, and therefore, core values should be the basis for all organizational behavior, integrated into everything a company does. Applying values in practice is an ongoing process and companies should continuously work towards creating a more value-based organizational culture. If a company does this effectively, they will most likely become more successful with stakeholders as well as financially. Companies looking to turn their values into actions should start with a self-assessment. Employee surveys are effective in assessing the current level of value implementation, since employees have valuable, first-hand information regarding the situations and behaviors they face in their everyday work. After the self-assessment, things like management commitment, communication, training, and support are key success factors in value implementation.
Resumo:
This thesis studies the use of heuristic algorithms in a number of combinatorial problems that occur in various resource constrained environments. Such problems occur, for example, in manufacturing, where a restricted number of resources (tools, machines, feeder slots) are needed to perform some operations. Many of these problems turn out to be computationally intractable, and heuristic algorithms are used to provide efficient, yet sub-optimal solutions. The main goal of the present study is to build upon existing methods to create new heuristics that provide improved solutions for some of these problems. All of these problems occur in practice, and one of the motivations of our study was the request for improvements from industrial sources. We approach three different resource constrained problems. The first is the tool switching and loading problem, and occurs especially in the assembly of printed circuit boards. This problem has to be solved when an efficient, yet small primary storage is used to access resources (tools) from a less efficient (but unlimited) secondary storage area. We study various forms of the problem and provide improved heuristics for its solution. Second, the nozzle assignment problem is concerned with selecting a suitable set of vacuum nozzles for the arms of a robotic assembly machine. It turns out that this is a specialized formulation of the MINMAX resource allocation formulation of the apportionment problem and it can be solved efficiently and optimally. We construct an exact algorithm specialized for the nozzle selection and provide a proof of its optimality. Third, the problem of feeder assignment and component tape construction occurs when electronic components are inserted and certain component types cause tape movement delays that can significantly impact the efficiency of printed circuit board assembly. Here, careful selection of component slots in the feeder improves the tape movement speed. We provide a formal proof that this problem is of the same complexity as the turnpike problem (a well studied geometric optimization problem), and provide a heuristic algorithm for this problem.
Resumo:
Yritysostojen määrä on historiallisen suuri 2000-luvulla, vaikka melkein puolet niistä epäonnistuu. Aineettomilla tekijöillä, kuten organisaatiokulttuureilla, on keskeinen rooli yritysostojen onnistumisissa. Myös case yritys on aktiivinen yritysostoissa ja haluaa arvioida integraatioprosessinsa tehokkuutta. Siten diplomityön tarkoituksena on luoda työkalu organisaatiokulttuurien yhteensopivuuden arvioimiseksi, jotta ostopäätöksentekoa sekä integraation suunnittelua voitaisiin tukea paremmin yrityksessä. Diplomityö vastaakin kysymyksiin, kuten miten arvioida kulttuurista yhteensopivuutta ennen integraatiota integraatioprosessin parantamiseksi sekä mitkä ovat olleet kaikkein ongelmallisimmat ja toisaalta kaikkein menestyksekkäimmät kulttuuritekijät tutkitussa integraatiossa. Kulttuurisen yhteensopivuuden arviointi tulisi nähdä prosessina osana yrityskauppaa. Prosessin tulisi alkaa kulttuurisen integraation tavoitteiden määrittämisellä sekä organisaatiokulttuurin käsitteen ymmärtämisellä. Kulttuurianalyysi tulisi suorittaa työpajan avulla. Sen tulisi käsitellä ainakin yhdeksän kulttuurin osa-aluetta: innovatiivisuus, päätöksenteko, ihmissuuntautuneisuus, kommunikaatio, kontrolli, asiakassuuntautuneisuus, ajanhallinta, identifikaatio, sekä kollektivismi. Lisäksi kuhunkin dimensioon liittyvään kysymykseen tulisi vastata pisteillä yhdestä viiteen, jolloin voidaan piirtää kulttuurisen yhteensopivuuden kuvio. Tämän jälkeen johdon tulisi keskustella tuloksista vielä kerran tarkemmin ja lopulta koota tulokset kirjalliseksi raportiksi. Tutkitussa integraatiossa parhaiten integraatiota tukivat ihmissuuntautuneisuus sekä ajanhallinta (työn ja vapaa-ajan välinen tasapaino sekä tulevaisuus-suuntautuneisuus). Haasteellisimmat kulttuuritekijät koskivat päätöksentekoa, kommunikaatiota ja kontrollia, jotka vaikuttavat olevan tyypillisiä ongelmia ison yrityksen ostaessa pienemmän yrityksen.
Resumo:
Increase of computational power and emergence of new computer technologies led to popularity of local communications between personal trusted devices. By-turn, it led to emergence of security problems related to user data utilized in such communications. One of the main aspects of the data security assurance is security of software operating on mobile devices. The aim of this work was to analyze security threats to PeerHood, software intended for performing personal communications between mobile devices regardless of underlying network technologies. To reach this goal, risk-based software security testing was performed. The results of the testing showed that the project has several security vulnerabilities. So PeerHood cannot be considered as a secure software. The analysis made in the work is the first step towards the further implementation of PeerHood security mechanisms, as well as taking into account security in the development process of this project.
Resumo:
The condensation rate has to be high in the safety pressure suppression pool systems of Boiling Water Reactors (BWR) in order to fulfill their safety function. The phenomena due to such a high direct contact condensation (DCC) rate turn out to be very challenging to be analysed either with experiments or numerical simulations. In this thesis, the suppression pool experiments carried out in the POOLEX facility of Lappeenranta University of Technology were simulated. Two different condensation modes were modelled by using the 2-phase CFD codes NEPTUNE CFD and TransAT. The DCC models applied were the typical ones to be used for separated flows in channels, and their applicability to the rapidly condensing flow in the condensation pool context had not been tested earlier. A low Reynolds number case was the first to be simulated. The POOLEX experiment STB-31 was operated near the conditions between the ’quasi-steady oscillatory interface condensation’ mode and the ’condensation within the blowdown pipe’ mode. The condensation models of Lakehal et al. and Coste & Lavi´eville predicted the condensation rate quite accurately, while the other tested ones overestimated it. It was possible to get the direct phase change solution to settle near to the measured values, but a very high resolution of calculation grid was needed. Secondly, a high Reynolds number case corresponding to the ’chugging’ mode was simulated. The POOLEX experiment STB-28 was chosen, because various standard and highspeed video samples of bubbles were recorded during it. In order to extract numerical information from the video material, a pattern recognition procedure was programmed. The bubble size distributions and the frequencies of chugging were calculated with this procedure. With the statistical data of the bubble sizes and temporal data of the bubble/jet appearance, it was possible to compare the condensation rates between the experiment and the CFD simulations. In the chugging simulations, a spherically curvilinear calculation grid at the blowdown pipe exit improved the convergence and decreased the required cell count. The compressible flow solver with complete steam-tables was beneficial for the numerical success of the simulations. The Hughes-Duffey model and, to some extent, the Coste & Lavi´eville model produced realistic chugging behavior. The initial level of the steam/water interface was an important factor to determine the initiation of the chugging. If the interface was initialized with a water level high enough inside the blowdown pipe, the vigorous penetration of a water plug into the pool created a turbulent wake which invoked the chugging that was self-sustaining. A 3D simulation with a suitable DCC model produced qualitatively very realistic shapes of the chugging bubbles and jets. The comparative FFT analysis of the bubble size data and the pool bottom pressure data gave useful information to distinguish the eigenmodes of chugging, bubbling, and pool structure oscillations.
Resumo:
En option är ett finansiellt kontrakt som ger dess innehavare en rättighet (men medför ingen skyldighet) att sälja eller köpa någonting (till exempel en aktie) till eller från säljaren av optionen till ett visst pris vid en bestämd tidpunkt i framtiden. Den som säljer optionen binder sig till att gå med på denna framtida transaktion ifall optionsinnehavaren längre fram bestämmer sig för att inlösa optionen. Säljaren av optionen åtar sig alltså en risk av att den framtida transaktion som optionsinnehavaren kan tvinga honom att göra visar sig vara ofördelaktig för honom. Frågan om hur säljaren kan skydda sig mot denna risk leder till intressanta optimeringsproblem, där målet är att hitta en optimal skyddsstrategi under vissa givna villkor. Sådana optimeringsproblem har studerats mycket inom finansiell matematik. Avhandlingen "The knapsack problem approach in solving partial hedging problems of options" inför en ytterligare synpunkt till denna diskussion: I en relativt enkel (ändlig och komplett) marknadsmodell kan nämligen vissa partiella skyddsproblem beskrivas som så kallade kappsäcksproblem. De sistnämnda är välkända inom en gren av matematik som heter operationsanalys. I avhandlingen visas hur skyddsproblem som tidigare lösts på andra sätt kan alternativt lösas med hjälp av metoder som utvecklats för kappsäcksproblem. Förfarandet tillämpas även på helt nya skyddsproblem i samband med så kallade amerikanska optioner.
Resumo:
Vad händer i tidvattenzonen? Var går gränsen mellan land och hav, vad händer i tidvattenzonen och vem ansvarar för detta? I västra Indiska oceanen (VIO) kan avståndet mellan den lägsta nivån för lågvattnet och den högsta nivån för högvattnet vara flera kilometer och nivåskillnaderna upp till 6 meter och detta skapar ett stort och föränderligt område. Syftet med min avhandling är att öka förståelsen för tidvattenzonen i tropiska och subtropiska västra Indiska oceanen. Sammanfattningsvis visar mina studier att det finns ett mycket stort värde i den komplexa tidvattenzonen, men också att det här området hotas från både land och hav, genom t.ex. överexploatering, erosion och föroreningar. Uttnyttjandet av tidvattenzonen är stort och min avhandling har visat att aktiviteter såsom fiske i form av plocking av musslor och andra ryggradslösa djur och hamnaktiviteter påverkar den biologiska mångfalden negativt, vilket leder till försämrad levnadsstandard för resursutnyttjande människor i regionen. För att förbättra situationen krävs det mer forskning, miljöövervakning och bättre förvaltning av tidvattenzonen. Experter i regionen har rangordnat förslag på förvaltningsstrategier som skulle kunna testas för att förbättra miljön och skapa ett mer hållbart nyttjande. Avhandlingen visar även att det är möjligt att använda fjärranalysteknik såsom satellitbildsanalys för att kvantifiera mängden sjögräsvegetation (i form av biomassa), vilket kan ha stor betydelse för att förbättra storskalig miljöövervakning av kustnära naturtyper (habitat). I avhandlingsarbetet har jag använt mig av ett multidisciplinärt tillvägagångssätt och använt metoder såsom ekologisk och biologisk provtagning, intervjuer, observationer, diskussionsgrupper, frågeformulär och fjärranalys. Resultaten presenterade i denna avhandling ger en ökad kunskap om tidvattenzonen i utvecklingsländerna inom VIO-regionen som kan användas för att initiera och fortsätta att utveckla hållbara förvaltningsstrategier av biologiska resurser.
Resumo:
The biological variation in nature is called biodiversity. Anthropogenic pressures have led to a loss of biodiversity, alarming scientists as to what consequences declining diversity has for ecosystem functioning. The general consensus is that diversity (e.g. species richness or identity) affects functioning and provides services from which humans benefit. The aim of this thesis was to investigate how aquatic plant species richness and identity affect ecosystem functioning in terms of processes such as primary production, nutrient availability, epifaunal colonization and properties e.g. stability of Zostera marina subjected to shading. The main work was carried out in the field and ranged temporally from weeklong to 3.5 months-long experiments. The experimental plants used frequently co-occur in submerged meadows in the northern Baltic Sea and consist of eelgrass (Z. marina), perfoliate pondweed (Potamogeton perfoliatus), sago pondweed (P. pectinatus), slender-leaved pondweed (P. filiformis) and horned pondweed (Zannichellia palustris). The results showed that plant richness affected epifaunal community variables weakly, but had a strong positive effect on infaunal species number and functional diversity, while plant identity had strong effects on amphipods (Gammarus spp.), of which abundances were higher in plant assemblages consisting of P. perfoliatus. Depending on the starting standardizing unit, plant richness showed varying effects on primary production. In shoot density-standardized plots, plant richness increased the shoot densities of three out of four species and enhanced the plant biomass production. Both positive complementarity and selection effects were found to underpin the positive biodiversity effects. In shoot biomass-standardized plots, richness effects only affected biomass production of one species. Negative selection was prevalent, counteracting positive complementarity, which resulted in no significant biodiversity effect. The stability of Z. marina was affected by plant richness in such that Z. marina growing in polycultures lost proportionally less biomass than Z. marina in monocultures and thus had a higher resistance to shading. Monoculture plants in turn gained biomass faster, and thereby had a faster recovery than Z. marina growing in polycultures. These results indicate that positive interspecific interactions occurred during shading, while the faster recovery of monocultures suggests that the change from shading stress to recovery resulted in a shift from positive interactions to resource competition between species. The results derived from this thesis show that plant diversity affects ecosystem functioning and contribute to the growing knowledge of plant diversity being an important component of aquatic ecosystems. Diverse plant communities sustain higher primary productivity than comparable monocultures, affect faunal communities positively and enhance stability. Richness and identity effects vary, and identity has generally stronger effects on more variables than richness. However, species-rich communities are likely to contain several species with differing effects on functions, which renders species richness important for functioning. Mixed meadows add to coastal ecosystem functioning in the northern Baltic Sea and may provide with services essential for human well-being.
Resumo:
Alcohol consumption during pregnancy can potentially affect the developing fetus in devastating ways, leading to a range of physical, neurological, and behavioral alterations most accurately termed Fetal Alcohol Spectrum Disorders (FASD). Despite the fact that it is a preventable disorder, prenatal alcohol exposure today constitutes a leading cause of intellectual disability in the Western world. In Western countries where prevalence studies have been performed the rates of FASD exceed, for example, autism spectrum disorders, Down’s syndrome and cerebral palsy. In addition to the direct effects of alcohol, children and adolescents with FASD are often exposed to a double burden in life, as their neurological sequelae are accompanied by adverse living surroundings exposing them to further environmental risk. However, children with FASD today remain remarkably underdiagnosed by the health care system. This thesis forms part of a larger multinational research project, The Collaborative Initiative on Fetal Alcohol Spectrum Disorders (the CIFASD), initiated by the National Institute of Alcohol Abuse and Alcoholism (NIAAA) in the U.S.A. The general aim of the present thesis was to examine a cohort of children and adolescents growing up with fetal alcohol-related damage in Finland. The thesis consists of five studies with a broad focus on diagnosis, cognition, behavior, adaptation and brain metabolic alterations in children and adolescents with FASD. The participants consisted of four different groups: one group with histories of prenatal exposure to alcohol, the FASD group; one IQ matched contrast group mostly consisting of children with specific learning disorder (SLD); and two typically-developing control groups (CON1 and CON2). Participants were identified through medical records, random sampling from the Finnish national population registry and email alerts to students. Importantly, the participants in the present studies comprise a group of very carefully clinically characterized children with FASD as the studies were performed in close collaboration with leading experts in the field (Prof. Edward Riley and Prof. Sarah Mattson, Center for Behavioral Teratology, San Diego State University, U.S.A; Prof. Eugene Hoyme, Sanford School of Medicine, University of South Dakota, U.S.A.). In the present thesis, the revised Institute of Medicine diagnostic criteria for FASD were tested on a Finnish population and found to be a reliable tool for differentiating among the subgroups of FASD. A weighted dysmorphology scoring system proved to be a valuable additional adjunct in quantification of growth deficits and dysmorphic features in children with FASD (Study 1). The purpose of Study 2 was to clarify the relationship between alcohol-related dysmorphic features and general cognitive capacity. Results showed a significant correlation between dysmorphic features and cognitive capacity, suggesting that children with more severe growth deficiency and dysmorphic features have more cognitive limitations. This association was, however, only moderate, indicating that physical markers and cognitive capacity not always go hand in hand in individuals with FASD. Behavioral problems in the FASD group proved substantial compared to the typically developing control group. In Study 3 risk and protective factors associated with behavioral problems in the FASD group were explored further focusing on diagnostic and environmental factors. Two groups with elevated risks for behavioral problems emerged: length of time spent in residential care and a low dysmorphology score proved to be the most pervasive risk factor for behavioral problems. The results underscore the clinical importance of appropriate services and care for less visibly alcohol affected children and highlight the need to attend to children with FASD being raised in institutions. With their background of early biological and psychological impairment compounded with less opportunity for a close and continuous caregiver relationship, such children seem to run an especially great risk of adverse life outcomes. Study 4 focused on adaptive abilities such as communication, daily living skills and social skills, in other words skills that are important for gradually enabling an independent life, maintain social relationships and allow the individual to become integrated into society. The results showed that adaptive abilities of children and adolescents growing up with FASD were significantly compromised compared to both typically-developing peers and IQ-matched children with SLD. Clearly different adaptive profiles were revealed where the FASD group performed worse than the SLD group, who in turn performed worse than the CON1 group. Importantly, the SLD group outperformed the FASD group on adaptive behavior in spite of comparable cognitive levels. This is the first study to compare adaptive abilities in a group of children and adolescents with FASD relative to both a contrast group of IQ-matched children with SLD and to a group of typically-developing peers. Finally, in Study 5, through magnetic resonance spectroscopic imaging (MRS) evidence of longstanding neurochemical alterations were observed in adolescents and young adults with FASD related to alcohol exposure in utero 14-20 years earlier. Neurochemical alterations were seen in several brain areas: in frontal and parietal cortices, corpus callosum, thalamus and frontal white matter areas as well as in the cerebellar dentate nucleus. The findings are compatible with neuropsychological findings in FASD. Glial cells seemed to be more affected than neurons. In conclusion, more societal efforts and resources should be focused on recognizing and diagnosing FASD, and supporting subgroups with elevated risk of poor outcome. Without adequate intervention children and adolescents with FASD run a great risk of marginalization and social maladjustment, costly not only to society but also to the lives of the many young people with FASD.