35 resultados para Methodological importance
Resumo:
Large carnivore populations are currently recovering from past extirpation efforts and expanding back into their original habitats. At the same time human activities have resulted in very few wilderness areas left with suitable habitats and size large enough to maintain populations of large carnivores without human contact. Consequently the long-term future of large carnivores depends on their successful integration into landscapes where humans live. Thus, understanding their behaviour and interaction with surrounding habitats is of utmost importance in the development of management strategies for large carnivores. This applies also to brown bears (Ursus arctos) that were almost exterminated from Scandinavia and Finland at the turn of the century, but are now expanding their range with the current population estimates being approximately 2600 bears in Scandinavia and 840 in Finland. This thesis focuses on the large-scale habitat use and population dynamics of brown bears in Scandinavia with the objective to develop modelling approaches that support the management of bear populations. Habitat analysis shows that bear home ranges occur mainly in forested areas with a low level of human influence relative to surrounding areas. Habitat modelling based on these findings allows identification and quantification of the potentially suitable areas for bears in Scandinavia. Additionally, this thesis presents novel improvements to home range estimation that enable realistic estimates of the effective area required for the bears to establish a home range. This is achieved through fitting to the radio-tracking data to establish the amount of temporal autocorrelation and the proportion of time spent in different habitat types. Together these form a basis for the landscape-level management of the expanding population. Successful management of bears requires also assessment of the consequences of harvest on the population viability. An individual-based simulation model, accounting for the sexually selected infanticide, was used to investigate the possibility of increasing the harvest using different hunting strategies, such as trophy harvest of males. The results indicated that the population can sustain twice the current harvest rate. However, harvest should be changed gradually while carefully monitoring the population growth as some effects of increased harvest may manifest themselves only after a time-delay. The results and methodological improvements in this thesis can be applied to the Finnish bear population and to other large carnivores. They provide grounds for the further development of spatially-realistic management-oriented models of brow bear dynamics that can make projections of the future distribution of bears while accounting for the development of human activities.
Resumo:
Benthic-pelagic coupling describes processes that operate across and between the seafloor and open-water ecosystems. In soft-sediment communities, bioturbation by sediment-dwelling and epibenthic organisms may strongly shape habitat characteristics and influence processes, e.g. biogeochemical cycling, which supplies bioavailable nutrients to pelagic primary producers. In addition, benthic fauna may mediate benthic-pelagic coupling by affecting the survival and hatching of zooplankton dormant eggs in the sediment. In the shallow waters and seasonally fluctuating environment of the Baltic Sea, emergence from the seafloor essentially contributes to the dynamics of zooplankton pelagic populations. In this thesis, I examine how benthic organisms with different functional traits affect the link between the benthic and pelagic systems in the northern Baltic Sea. By means of experimental laboratory studies, the effects of sediment-dwelling (Monoporeia affinis, Macoma balthica and Marenzelleria spp.) and nectobenthic (Mysis spp.) taxa on the survival and hatching of zooplankton benthic eggs and on benthic nutrient fluxes and sediment structure were investigated. In the predation studies, the nectobenthic mysids Mysis spp. preyed upon benthic eggs of the cladoceran Bosmina longispina maritima (syn. B. coregoni maritima), both in pelagic and benthic environments. Of the sediment-dwelling species, the amphipod M. affinis and the bivalve M. balthica reduced the number of cladoceran eggs in the sediment, whereas the polychaetes Marenzelleria spp. had no effects on cladoceran eggs. Both M. balthica and M. affinis also increased the mortality rates of benthic eggs of copepods and rotifers. It was estimated that zooplankton eggs provide an additional carbon source for food-limited benthic communities. The results indicate that predation pressure on zooplankton benthic eggs may be strong, but varies widely depending on the season and the functional characteristics of the macrofauna. Macoma balthica buried cladoceran eggs and a fluorescent tracer from the sediment surface to a depth of 3 4 cm, indicating efficient sediment mixing. In contrast, the other taxa had fewer effects on particle distributions. In addition to organic matter mineralization, particle mixing is crucial to the success of benthic recruitment of zooplankton, since only eggs close to the sediment surface may hatch. Macoma balthica and M. affinis altered the patterns of zooplankton emergence from the sediment. In general, the highest emergence rates were observed in the absence of macroscopic fauna, and M. balthica exerted a stronger suppressive effect than M. affinis. Moreover, copepods were less severely affected than cladocerans, while only one species (Temora longicornis) clearly benefited from the presence of the macrofauna. These differences probably result from species-specific differences in the resistance of eggs to disturbances. The results show that benthic fauna may considerably alter the patterns of zooplankton emergence from the seafloor, thereby shaping zooplankton pelagic populations. The semi-motile M. balthica and Marenzelleria spp. increased the fluxes of phosphate and ammonium from the sediment to the water, whereas the motile M. affinis and Mysis mixta had a contrasting effect. In the eutrophied Baltic Sea, efficient internal cycling of bioavailable nutrients forms a strong feedback inhibiting the recovery of the ecosystem. Based on the results, a change in species dominance from the two motile taxa, susceptible to oxygen deficiency, to the more tolerant semi-motile taxa provides additional feedback, strengthening internal nutrient cycling and accelerating eutrophication, with deteriorating near-bottom oxygen conditions and changes in the benthic communities. In shallow-water ecosystems, benthic nutrient regeneration plays a key role in determining the overall productivity of the ecosystem. In addition, the results of this study show that the communities in the benthos may essentially contribute to the structure of those in the plankton.
Resumo:
The neurotransmitter serotonin (5-HT) modulates many functions important for life, e.g., appetite and body temperature, and controls development of the neural system. Disturbed 5-HT function has been implicated in mood, anxiety and eating disorders. The serotonin transporter (SERT) controls the amount of effective 5-HT by removing it from the extracellular space. Radionuclide imaging methods single photon emission tomography (SPET) and positron emission tomography (PET) enable studies on the brain SERTs. This thesis concentrated on both methodological and clinical aspects of the brain SERT imaging using SPET. The first study compared the repeatability of automated and manual methods for definition of volumes of interest (VOIs) in SERT images. The second study investigated within-subject seasonal variation of SERT binding in healthy young adults in two brain regions, the midbrain and thalamus. The third study investigated the association of the midbrain and thalamic SERT binding with Bulimia Nervosa (BN) in female twins. The fourth study investigated the association of the midbrain and hypothalamic/thalamic SERT binding and body mass index (BMI) in monozygotic (MZ) twin pairs. Two radioligands for SERT imaging were used: [123I]ADAM (studies I-III) and [123I]nor-beta-CIT (study IV). Study subjects included young adult MZ and dizygotic (DZ) twins screened from the FinnTwin16 twin cohort (studies I-IV) and healthy young adult men recruited for study II. The first study validated the use of an automated brain template in the analyses of [123I]ADAM images and proved automated VOI definition more reproducible than manual VOI definition. The second study found no systematic within-subject variation in SERT binding between scans done in summer and winter in either of the investigated brain regions. The third study found similar SERT binding between BN women (including purging and non-purging probands), their unaffected female co-twins and other healthy women in both brain regions; in post hoc analyses, a subgroup of purging BN women had significantly higher SERT binding in the midbrain as compared to all healthy women. In the fourth study, MZ twin pairs were divided into twins with higher BMI and co-twins with lower BMI; twins with higher BMI were found to have higher SERT binding in the hypothalamus/thalamus than their leaner co-twins. Our results allow the following conclusions: 1) No systematic seasonal variation exists in the midbrain and thalamus between SERT binding in summer and winter. 2) In a population-based sample, BN does not associate with altered SERT status, but alterations are possible in purging BN women. 3) The higher SERT binding in MZ twins with higher BMIs as compared to their leaner co-twins suggests non-genetic association between acquired obesity and the brain 5-HT system, which may have implications on feeding behavior and satiety.
Resumo:
The resources of health systems are limited. There is a need for information concerning the performance of the health system for the purposes of decision-making. This study is about utilization of administrative registers in the context of health system performance evaluation. In order to address this issue, a multidisciplinary methodological framework for register-based data analysis is defined. Because the fixed structure of register-based data indirectly determines constraints on the theoretical constructs, it is essential to elaborate the whole analytic process with respect to the data. The fundamental methodological concepts and theories are synthesized into a data sensitive approach which helps to understand and overcome the problems that are likely to be encountered during a register-based data analyzing process. A pragmatically useful health system performance monitoring should produce valid information about the volume of the problems, about the use of services and about the effectiveness of provided services. A conceptual model for hip fracture performance assessment is constructed and the validity of Finnish registers as a data source for the purposes of performance assessment of hip fracture treatment is confirmed. Solutions to several pragmatic problems related to the development of a register-based hip fracture incidence surveillance system are proposed. The monitoring of effectiveness of treatment is shown to be possible in terms of care episodes. Finally, an example on the justification of a more detailed performance indicator to be used in the profiling of providers is given. In conclusion, it is possible to produce useful and valid information on health system performance by using Finnish register-based data. However, that seems to be far more complicated than is typically assumed. The perspectives given in this study introduce a necessary basis for further work and help in the routine implementation of a hip fracture monitoring system in Finland.
Resumo:
Follicular lymphoma (FL) is the second most common non-Hodgkin lymphoma. It is an indolent and clinically heterogeneous disease, which is generally considered incurable. Currently, immunochemotherapy has significantly improved the outcome of FL patients. This is based on the combination of rituximab, a monoclonal anti-CD20 antibody, with chemotherapy, and is used at present as a standard first-line therapy in FL. Thus far, however, patients have been selected for treatment based on clinical risk factors and indices that were developed before the rituximab era. Therefore, there is a growing need to understand the molecular mechanisms underlying the disease, which would not only provide information to predict survival in the rituximab era, but also enable the design of more targeted therapeutic strategies. In this study, our aim was to identify genes predicting the outcome in FL patients treated with immunochemotherapy. Thus, we performed a cDNA microarray with 24 FL patients. When gene expression differences from diagnostic tumour samples were related to the clinical outcome, we identified novel genes with a prognostic impact on survival. The expression of selected genes was further characterized with quantitative PCR and immunohistochemistry (IHC). Interestingly, the prognostic influence of these genes was often associated with their expression in non-malignant cells instead of tumour cells. Based on the observed gene expression patterns, we analyzed the abundance and prognostic value of non-malignant immune cells in 95-98 FL patients treated with immunochemotherapy. We observed that a high content of tumour-associated macrophages was a marker of a favourable prognosis. In contrast, the accumulation of mast cells correlated with a poor outcome and was further associated with tumour vascularity. Increased microvessel density also correlated with an inferior outcome. In addition, we used the same microarray data with a systems biology approach to identify signalling pathways or groups of genes capable of separating patients with favourable or adverse outcomes. Among the transcripts, there were many genes associated with signal transducers and activators of the transcription (STAT5a) pathway. When IHC was used as validation, STAT5a expression was mostly observed in T-cells and follicular dendritic cells, and expression was found to predict a favourable outcome. In cell cultures, rituximab was observed to induce the expression of STAT5a-associated interleukins in human lymphoma cell lines, which might provide a possible link for the cross-talk between rituximab-induced FL cells and their microenvironment. In conclusion, we have demonstrated that the microenvironment has a prognostic role in FL patients treated with immunochemotherapy. The results also address the importance of re-evaluating the prognostic markers in the rituximab era of lymphoma therapies.
Resumo:
Service researchers and practitioners have repeatedly claimed that customer service experiences are essential to all businesses. Therefore comprehension of how service experience is characterised in research is an essential element for its further development through research. The importance of greater in-depth understanding of the phenomenon of service experience has been acknowledged by several researchers, such as Carú and Cova and Vargo and Lusch. Furthermore, Service-Dominant (S-D) logic has integrated service experience to value by emphasising in its foundational premises that value is phenomenologically (experientially) determined. The present study analyses how the concept of service experience has been characterised in previous research. As such, it puts forward three ways to characterise it in relation to that research: 1) phenomenological service experience relates to the value discussion in S-D logic and interpretative consumer research, 2) process-based service experience relates to understanding service as a process, and 3) outcome-based service experience relates to understanding service experience as one element in models linking a number of variables or attributes to various outcomes. Focusing on the phenomenological service experience, the theoretical purpose of the study is to characterise service experience based on the phenomenological approach. In order to do so, an additional methodological purpose was formulated: to find a suitable methodology for analysing service experience based on the phenomenological approach. The study relates phenomenology to a philosophical Husserlian and social constructionist tradition studying phenomena as they appear in our experience in a social context. The study introduces Event-Based Narrative Inquiry Technique (EBNIT), which combines critical events with narratives and metaphors. EBNIT enabled the analysis of lived and imaginary service experiences as expressed in individual narratives. The study presents findings of eight case studies within service innovation of Web 2.0, mobile service, location aware service and public service in the municipal sector. Customers’ and service managers’ stories about their lived private and working lifeworld were the foundation for their ideal service experiences. In general, the thesis finds that service experiences are (1) subjective, (2) context-specific, (3) cumulative, (4) partially socially constructed, (5) both lived and imaginary, (6) temporally multiple-dimensional, and (7) iteratively related to perceived value. In addition to customer service experience, the thesis brings empirical evidence of managerial service experience of front-line managers experiencing the service they manage and develop in their working lifeworld. The study contributes to S-D logic, service innovation and service marketing and management in general by characterising service experience based on the phenomenological approach and integrating it to the value discussion. Additionally, the study offers a methodological approach for further exploration of service experiences. The study discusses managerial implications in conjunction with the case studies and discusses them in relation to service innovation.
Resumo:
A defining characteristic of most service encounters is that they are strongly influenced by interactions in which both the consumer and the service personnel are playing integral roles. Such is the importance of this interaction that it has even been argued that for the consumer, these encounters are in fact the service. Given this, it is not surprising that interactions involving communication and customer participation in the service encounters have received considerable attention within the field of services marketing. Much of the research on interactions and communication in services, however, appear to have assumed that the consumer and the service personnel by definition are perfectly able to interact and communicate effortlessly with each other. Such communication would require a common language, and in order to be able to take this for granted the market would need to be fairly homogenous. The homogenous country, however, and with it the homogenous market, would appear to be gone. It is estimated that more than half the consumers in the world are already speaking more than one language. For a company entering a new market, language can be a major barrier that firms may underestimate, and understanding language influence across different markets is important for international companies. The service literature has taken a common language between companies and consumers for granted but this is not matched by the realities on the ground in many markets. Owing to the communicational and interaction-oriented nature of services, the lack of a common language between the consumer and the service provider is a situation that could cause problems. A gap exists in the service theory, consisting of a lack of knowledge concerning how language influences consumers in service encounters. By addressing this gap, the thesis contributes to an increased understanding of service theory and provides a better practical understanding for service companies of the importance of native language use for consumers. The thesis consists of four essays. Essay one is conceptual and addresses how sociolinguistic research can be beneficial for understanding consumer language preferences. Essay two empirically shows how the influence of language varies depending on the nature of the service, essay three shows that there is a significant difference in language preferences between female and male consumers while essay four empirically compares consumer language preferences in Canada and Finland, finding strong similarities but also indications of difference in the motives for preferring native language use. The introduction of the thesis outlines the existence of a research gap within the service literature, a gap consisting of the lack of research into how native language use may influence consumers in service encounters. In addition, it is described why this gap is of importance to services and why its importance is growing. Building on this situation, the purpose of the thesis is to establish the existence of language influence in service encounters and to extend the knowledge of how language influences consumers on multilingual markets.
Resumo:
This study contributes to the mutual fund literature by looking at performance persistence on a fund family level, allowing for individual equity, bond and balanced funds to be included under single family umbrellas. The study is conducted on the emerging Finnish mutual fund market, an environment in which the importance of superior fund family teams is likely to be accentuated. Using both non–parametric and parametric tests we find robust evidence of performance persistence for the fund families. Persistence is particularly strong in the first half of the investigation period, which highlights the importance of fund families at early stages of market development.
Resumo:
This Working Paper reports the background to the first stage of the ongoing research project, The Quest for Well-being in Growth Industries: A Collaborative Study in Finland and Scotland, conducted under the auspices of the Academy of Finland research programme The Future of Work and Well-being (2008-2011). This collaborative project provides national and transnational data, analysis and outputs. The study is being conducted in the Department of Management and Organisation, Hanken School of Economics, Finland, in collaboration with Glasgow Caledonian University, University of East London, Heriot-Watt University and Reading University, UK. The project examines policies and practices towards the enhancement of work-related well-being in growth industries, and contradictory pressures and tensions posed in this situation. The overall aim is to evaluate the development, implementation and use of work-related well-being policies in four selected growth industries. These sectors – electronics, care, finance and accounting, and tourism – have been selected on the basis of European Union and national forecasts, and demographic and socio-economic trends in employment. In this working paper we outline the background to the research study, the initial research plan, and how the survey of employers has been constructed. The working paper concludes with a brief discussion of general ongoing research issues arising in the project.
Resumo:
The overlapping sound pressure waves that enter our brain via the ears and auditory nerves must be organized into a coherent percept. Modelling the regularities of the auditory environment and detecting unexpected changes in these regularities, even in the absence of attention, is a necessary prerequisite for orientating towards significant information as well as speech perception and communication, for instance. The processing of auditory information, in particular the detection of changes in the regularities of the auditory input, gives rise to neural activity in the brain that is seen as a mismatch negativity (MMN) response of the event-related potential (ERP) recorded by electroencephalography (EEG). --- As the recording of MMN requires neither a subject s behavioural response nor attention towards the sounds, it can be done even with subjects with problems in communicating or difficulties in performing a discrimination task, for example, from aphasic and comatose patients, newborns, and even fetuses. Thus with MMN one can follow the evolution of central auditory processing from the very early, often critical stages of development, and also in subjects who cannot be examined with the more traditional behavioural measures of auditory discrimination. Indeed, recent studies show that central auditory processing, as indicated by MMN, is affected in different clinical populations, such as schizophrenics, as well as during normal aging and abnormal childhood development. Moreover, the processing of auditory information can be selectively impaired for certain auditory attributes (e.g., sound duration, frequency) and can also depend on the context of the sound changes (e.g., speech or non-speech). Although its advantages over behavioral measures are undeniable, a major obstacle to the larger-scale routine use of the MMN method, especially in clinical settings, is the relatively long duration of its measurement. Typically, approximately 15 minutes of recording time is needed for measuring the MMN for a single auditory attribute. Recording a complete central auditory processing profile consisting of several auditory attributes would thus require from one hour to several hours. In this research, I have contributed to the development of new fast multi-attribute MMN recording paradigms in which several types and magnitudes of sound changes are presented in both speech and non-speech contexts in order to obtain a comprehensive profile of auditory sensory memory and discrimination accuracy in a short measurement time (altogether approximately 15 min for 5 auditory attributes). The speed of the paradigms makes them highly attractive for clinical research, their reliability brings fidelity to longitudinal studies, and the language context is especially suitable for studies on language impairments such as dyslexia and aphasia. In addition I have presented an even more ecological paradigm, and more importantly, an interesting result in view of the theory of MMN where the MMN responses are recorded entirely without a repetitive standard tone. All in all, these paradigms contribute to the development of the theory of auditory perception, and increase the feasibility of MMN recordings in both basic and clinical research. Moreover, they have already proven useful in studying for instance dyslexia, Asperger syndrome and schizophrenia.
Resumo:
XVIII IUFRO World Congress, Ljubljana 1986.