44 resultados para Up-conversion emission

em Helda - Digital Repository of University of Helsinki


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Temporomandibular disorders (TMD) and psychosocial factors reportedly associate. The underlying factors remain partially obscure, however, and further studies are required to clarify the relationships. The aims of this study were thus to assess in a non-patient working population the prevalence of TMD and related symptoms, and to clinically diagnose and follow the natural courses of TMD over a one-year period. In addition, possible comorbidity of temporomandibular and/or neck muscle pain and perceived stress and their impact on work performance were investigated, as well as how various psychosocial aspects relate to TMD. A questionnaire was mailed to all 30- to 55-year-old employees of the Finnish Broadcasting Company Ltd. whose employment in the Helsinki area had lasted at least five years (n = 1784). Of the 1339 subjects, who returned the questionnaire, 241 were examined according to the RDC/TMD and standard neck muscle palpation methods. Clinical signs of temporomandibular and/or neck muscle pain were found in 118 subjects. One-year follow-up TMD examinations were conducted on 211 subjects. The prevalence of frequent painless TMJ-related symptoms was 10%, orofacial pain 7%, neck pain 38%, and headache 15%. TMD diagnoses were: myofascial pain (13%), disc displacements (16%), and arthralgia, osteoarthritis, osteoarthrosis (4%). Chronic myofascial pain was present in 7% and chronic disc displacement with reduction in 11% of the subjects. Symptoms were significantly associated with almost all the studied psychosocial symptoms. Reduced work performance was significantly positively associated with continuous pain, severity of pain, and health stress perception, and according to logistic regression, somatization with the probability of having chronic myofascial pain. It could be concluded based on the results of this study among a non-patient working population that TMD and related symptoms are common and associated with psychosocial factors. Moreover, myofascial pain and disc displacement with reduction are the most common diagnoses of TMD. In addition, self-reported health related stress, and continuous pain in temporomandibular and/or neck muscles are associated with reduced work performance, and somatization is significantly associated with chronic myofascial pain.

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The aim of the study was to examine the effects of a smoking prevention program and smoking from early adolescence to early adulthood by using longitudinal data. In addition, predictors of smoking, smoking cessation, and associations of smoking with socio-economic factors and other health behaviours were assessed. The data was gathered in connection with the North Karelia Youth Project follow-up study during 15 years. A two-year cardiovascular disease risk factor prevention program was carried out among students from grades seven to nine in four schools in North Karelia. Two schools were selected from Kuopio province for the control schools. The North Karelia Project, a community-based cardiovascular disease prevention program, was implemented in the same area. At the baseline in 1978 the subjects were 13-year-olds (n=903) and in the following surveys 15-, 16-, 17-, 21- and 28-year-olds. The parents of the subjects were studied twice, in 1978 and 1980. A two-year intervention based on social influence approach prevented the onset of smoking for several years. The continuity of smoking from adolescence to adulthood was strong: most adolescent smokers were still smoking in adulthood. Moreover, approximately half of the 28-year-old smokers had started smoking after the age of 15. Previous smoking status and smoking by friends were the most important predictors of smoking. One third of all adolescent smokers had stopped smoking before the age of 28, averaging at 2.3 % annual decline. The socioeconomic status of the subject and, especially, education were strongly related to smoking, the lower socioeconomic groups smoking the most. Parental socioeconomic status and intergenerational social mobility were not significantly related to the smoking of the subject in adolescence or adulthood. Smoking was associated positively with the use of alcohol and negatively with physical activity from adolescence to adulthood. The results support the feasibility of a school-based social influence program with a community-based program in smoking prevention among adolescents. Strong continuity of smoking from adolescence to adulthood supports the importance of preventing the onset of smoking in adolescence. It would be useful to continue prevention programs also after the comprehensive school, since so many young start smoking after that. It would likewise be important to develop cessation programs tailor-made for adolescents and young adults. Additionally, the results support the importance of using methods based on social influence in smoking prevention and cessation programs, targeting especially such risk groups as those with low socioeconomic status as well as those with other unhealthy behaviours.

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The aims of this dissertation were 1) to investigate associations of weight status of adolescents with leisure activities, and computer and cell phone use, and 2) to investigate environmental and genetic influences on body mass index (BMI) during adolescence. Finnish twins born in 1983–1987 responded to postal questionnaires at the ages of 11-12 (5184 participants), 14 (4643 participants), and 17 years (4168 participants). Information was obtained on weight and height, leisure activities including television viewing, video viewing, computer games, listening to music, board games, musical instrument playing, reading, arts, crafts, socializing, clubs, sports, and outdoor activities, as well as computer and cell phone use. Activity patterns were studied using latent class analysis. The relationship between leisure activities and weight status was investigated using logistic and linear regression. Genetic and environmental effects on BMI were studied using twin modeling. Of individual leisure activities, sports were associated with decreased overweight risk among boys in both cross-sectional and longitudinal analyses, but among girls only cross-sectionally. Many sedentary leisure activities, such as video viewing (boys/girls), arts (boys), listening to music (boys), crafts (girls), and board games (girls), had positive associations with being overweight. Computer use was associated with a higher prevalence of overweight in cross-sectional analyses. However, musical instrument playing, commonly considered as a sedentary activity, was associated with a decreased overweight risk among boys. Four patterns of leisure activities were found: ‘Active and sociable’, ‘Active but less sociable’, ‘Passive but sociable’, and ‘Passive and solitary’. The prevalence of overweight was generally highest among the ‘Passive and solitary’ adolescents. Overall, leisure activity patterns did not predict overweight risk later in adolescence. An exception were 14-year-old ‘Passive and solitary’ girls who had the greatest risk of becoming overweight by 17 years of age. Heritability of BMI was high (0.58-0.83). Common environmental factors shared by family-members affected the BMI at 11-12 and 14 years but their effect had disappeared by 17 years of age. Additive genetic factors explained 90-96% of the BMI stability across adolescence. Genetic correlations across adolescence were high, which suggests similar genetic effects on BMI throughout adolescence, while unique environmental effects on BMI appeared to vary. These findings suggest that family-based interventions hold promise for obesity prevention into early and middle adolescence, but that later in adolescence obesity prevention should focus on individuals. A useful target could be adolescents' leisure time, and our findings highlight the importance of versatility in leisure activities.

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Objective: The aim of the present study was to examine co-twin dependence and its impact on twins' social contacts, leisure-time activities and psycho-emotional well-being. The role of co-twin dependence was also examined as a moderator of genetic and environmental influences on alcohol use in adolescence and in early adulthood. Methods: The present report is based on the Finnish Twin Cohort Study (FinnTwin16), a population-based study of five consecutive birth cohorts of Finnish twins born in the years 1975-1979. Baseline assessments were collected through mailed questionnaires, within two months of the twins' sixteenth birthday yielding replies from 5563 twin individuals. All respondent twins were sent follow-up questionnaires at ages of 17, 18½, and in early adulthood, when twins were 22-27 years old. Measures: The questionnaires included a survey of health habits and attitudes, a symptom checklist and questions about twins' relationships with parents, peers and co-twin. Measures used were twins' self-reports of their own dependence and their co-twin's dependence at age 16, reports of twins' leisure-time activities and social contacts, alcohol use, psychological distress and somatic symptoms both in adolescence and in early adulthood. Results: In the present study 25.6% of twins reported dependence on their co-twin. There were gender and zygosity differences in dependence, females and MZ twins were more likely to report dependence than males and DZ twins. Co-twin dependence can be viewed on one hand as an individual characteristic, but on the other hand as a pattern of dyadic interaction that is mutually regulated and reciprocal. Most of the twins (80.7%) were either concordantly co-twin dependent or concordantly co-twin independent. The associations of co-twin dependence with twins' social interactions and psycho-emotional characteristics were relatively consistent both in adolescence and in early adulthood. Dependence was related to higher contact frequency and a higher proportion of shared leisure-time activities between twin siblings at the baseline and the follow-up. Additionally co-twin dependence was associated with elevated levels of psycho-emotional distress and somatic complaints, especially in adolescence. In the framework of gene-environment interaction, these results suggest that the genetic contribution to individual differences in drinking patterns is dependent on the nature of the pair-wise relationship of twin siblings. Conclusions: The results of this study indicate that co-twin dependence is a genuine feature of the co-twin relationship and shows the importance of studying the impact of various features of co-twin relationships on individual twins' social and psycho-emotional life and well-being. Our study also offers evidence that differences in inter-personal relationships contribute to the effects of genetic propensities.

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Chronic myeloid leukemia (CML) is a malignant clonal blood disease that originates from a pluripotent hematopoietic stem cell. The cytogenetic hallmark of CML, the Philadelphia chromosome (Ph), is formed as a result of reciprocal translocation between chromosomes 9 and 22, which leads to a formation of a chimeric BCR-ABL fusion gene. The BCR-ABL protein is a constitutively active tyrosine kinase that changes the adhesion properties of cells, constitutively activates mitogenic signaling, enhances cell proliferation and reduces apoptosis. This results in leukemic growth and the clinical disease, CML. With the advent of targeted therapies against the BCR-ABL fusion protein, the treatment of CML has changed considerably during the recent decade. In this thesis, the clinical significance of different diagnostic methods and new prognostic factors in CML have been assessed. First, the association between two different methods for measuring CML disease burden (the RQ-PCR and the high mitotic index metaphase FISH) was assessed in bone marrow and peripheral blood samples. The correlation between positive RQ-PCR and metaphase FISH samples was high. However, RQ-PCR was more sensitive and yielded measurable transcripts in 40% of the samples that were negative by metaphase FISH. The study established a laboratory-specific conversion factor for setting up the International Scale when standardizing RQ-PCR measurements. Secondly, the amount of minimal residual disease (MRD) after allogeneic hematopoietic stem cell transplantation (alloHSCT) was determined. For this, metaphase FISH was done for the bone marrow samples of 102 CML patients. Most (68%), had no residual cells during the entire follow-up time. Some (12 %) patients had minor (<1%) MRD which decreased even further with time, whereas 19% had a progressive rise in MRD that exceeded 1% or had more than 1% residual cells when first detected. Residual cells did not become eradicated spontaneously if the frequency of Ph+ cells exceeded 1% during follow-up. Next, the impact of deletions in the derivative chromosome 9, was examined. Deletions were observed in 15% of the CML patients who later received alloHSCT. After alloHSCT, there was no difference in the total relapse rate in patients with or without deletions. Nor did the estimates of overall survival, transplant-related mortality, leukemia-free survival and relapse-free time show any difference between these groups. When conventional treatment regimens are used, the der(9) status could be an important criterion, in conjunction with other prognostic factors, when allogeneic transplantation is considered. The significance of der(9) deletions for patients treated with tyrosine kinase inhibitors is not clear and requires further investigation. In addition to the der(9) status of the patient, the significance of bone marrow lymphocytosis as a prognostic factor in CML was assessed. Bone marrow lymphocytosis during imatinib therapy was a positive predictive factor and heralded optimal response. When combined with major cytogenetic response at three months of treatment, bone marrow lymphocytosis predicted a prognostically important major molecular response at 18 months of imatinib treatment. Although the validation of these findings is warranted, the determination of the bone marrow lymphocyte count could be included in the evaluation of early response to imatinib treatment already now. Finally, BCR-ABL kinase domain mutations were studied in CML patients resistant against imatinib treatment. Point mutations detected in the kinase domain were the same as previously reported, but other sequence variants, e.g. deletions or exon splicing, were also found. The clinical significance of the other variations remains to be determined.

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The study focuses on the potential roles of the brick making industries in Sudan in deforestation and greenhouse gas emission due to the consumption of biofuels. The results were based on the observation of 25 brick making industries from three administrative regions in Sudan namely, Khartoum, Kassala and Gezira. The methodological approach followed the procedures outlined by the Intergovernmental Panel on Climate Change (IPCC). For predicting a serious deforestation scenario, it was also assumed that all of wood use for this particular purpose is from unsustainable sources. The study revealed that the total annual quantity of fuelwood consumed by the surveyed brick making industries (25) was 2,381 t dm. Accordingly, the observed total potential deforested wood was 10,624 m3, in which the total deforested round wood was 3,664 m3 and deforested branches was 6,961 m3. The study observed that a total of 2,990 t biomass fuels (fuelwood and dung cake) consumed annually by the surveyed brick making industries for brick burning. Consequently, estimated total annual emissions of greenhouse gases were 4,832 t CO2, 21 t CH4, 184 t CO, 0.15 t N20, 5 t NOX and 3.5 t NO while the total carbon released in the atmosphere was 1,318 t. Altogether, the total annual greenhouse gases emissions from biomass fuels burning was 5,046 t; of which 4,104 t from fuelwood and 943 t from dung cake burning. According to the results, due to the consumption of fuelwood in the brick making industries (3,450 units) of Sudan, the amount of wood lost from the total growing stock of wood in forests and trees in Sudan annually would be 1,466,000 m3 encompassing 505,000 m3 round wood and 961,000 m3 branches annually. By considering all categories of biofuels (fuelwood and dung cake), it was estimated that, the total emissions from all the brick making industries of Sudan would be 663,000 t CO2, 2,900 t CH4, 25,300 t CO, 20 t N2O, 720 t NOX and 470 t NO per annum, while the total carbon released in the atmosphere would be 181,000 t annually.

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This thesis studies the informational efficiency of the European Union emission allowance (EUA) market. In an efficient market, the market price is unpredictable and profits above average are impossible in the long run. The main research problem is does the EUA price follow a random walk. The method is an econometric analysis of the price series, which includes an autocorrelation coefficient test and a variance ratio test. The results reveal that the price series is autocorrelated and therefore a nonrandom walk. In order to find out the extent of predictability, the price series is modelled with an autoregressive model. The conclusion is that the EUA price is autocorrelated only to a small degree and that the predictability cannot be used to make extra profits. The EUA market is therefore considered informationally efficient, although the price series does not fulfill the requirements of a random walk. A market review supports the conclusion, but it is clear that the maturing of the market is still in process.

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Knowledge-sharing in a teamwork The study examines the link between knowledge-sharing that takes place in a team and the dimensions and objectives of the team s activities. The question the study poses is: How does knowledge-sharing in a team relate to the team s activities? The exchange of knowledge is examined using knowledge-sharing networks and the conversion model, which describes the process of knowledge formation. The answer to the question is sought through four empirical articles describing the activities of a team from the viewpoint of quality, fairness, power related to knowledge management, and performance. One of the articles used in the study describes the role of networks in work life more generally. It attempts to shed light on the manner in which team-related networks operate as part of a more extensive structure of organizational networks. Finland is one of the most eager users of teamwork, if numbers are used as a yardstick. About half of all Finnish wage earners worked in teams in 2009, and comparisons show that the use of teams in Finland is above the EU average. This study focuses on so-called semi-autonomous teams, which carry out permanent work tasks. In such teams, tasks are interdependent, and teams are jointly responsible for ensuring that the work is done. Team members may also, at least to some extent, agree between themselves on how the tasks are carried out and are able to take part in the decision-making process. Such teamwork makes knowledge-sharing an important element for the team s activities. Knowledge and knowledge-sharing have become a major resource, allowing organizations to operate and even compete in today s increasingly competitive markets. A single team or a single organization cannot, however, possess all the knowledge required for carrying out the tasks assigned to it. Although it is difficult to copy the knowledge generated in an organization, it is important to share the knowledge within and between organizations. External links supply teams and organizations with important knowledge that allows them to keep their operations up-to-date and their structures well-functioning. In fact, knowledge provides teams and organizations with an intangible resource that improves their capacity to interact with their environment and to adjust to it. For this reason, it is important to examine both the internal and external knowledge-sharing taking place in a team. The findings of the study show that in terms of quality, fairness, performance and the knowledge management issues concerning a team, its social network structure is both internally and externally connected with its activities. A team structure that is internally coherent and at the same time open to external contacts, is, with certain restrictions, connected with the quality, fairness, and performance of the team. The restrictions concern differences between procedural and interactional justice, public and private sectors, and the team leaders and ordinary team members. The role of the team leader is closely connected with the management of networks that are considered valuable. The results of the study indicate that teamwork is supervisor-dominated. Thus, teamwork does not substantially strengthen the influence of individual employees as players in knowledge-transfer networks. However, ordinary team members possess important peer contacts inside the organization. Teamwork clearly allows employees to interact in a democratic manner, and here the transfer of tacit knowledge plays an important role. Keywords: teamwork, knowledge-sharing, social networks, organization