23 resultados para HIV, primary resistance to antirretrovirales, virologic faulier, secondary resistance

em Helda - Digital Repository of University of Helsinki


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This academic work begins with a compact presentation of the general background to the study, which also includes an autobiography for the interest in this research. The presentation provides readers who know little of the topic of this research and of the structure of the educational system as well as of the value given to education in Nigeria. It further concentrates on the dynamic interplay of the effect of academic and professional qualification and teachers' job effectiveness in secondary schools in Nigeria in particular, and in Africa in general. The aim of this study is to produce a systematic analysis and rich theoretical and empirical description of teachers' teaching competencies. The theoretical part comprises a comprehensive literature review that focuses on research conducted in the areas of academic and professional qualification and teachers' job effectiveness, teaching competencies, and the role of teacher education with particular emphasis on school effectiveness and improvement. This research benefits greatly from the functionalist conception of education, which is built upon two emphases: the application of the scientific method to the objective social world, and the use of an analogy between the individual 'organism' and 'society'. To this end, it offers us an opportunity to define terms systematically and to view problems as always being interrelated with other components of society. The empirical part involves describing and interpreting what educational objectives can be achieved with the help of teachers' teaching competencies in close connection to educational planning, teacher training and development, and achieving them without waste. The data used in this study were collected between 2002 and 2003 from teachers, principals, supervisors of education from the Ministry of Education and Post Primary Schools Board in the Rivers State of Nigeria (N=300). The data were collected from interviews, documents, observation, and questionnaires and were analyzed using both qualitative and quantitative methods to strengthen the validity of the findings. The data collected were analyzed to answer the specific research questions and hypotheses posited in this study. The data analysis involved the use of multiple statistical procedures: Percentages Mean Point Value, T-test of Significance, One-Way Analysis of Variance (ANOVA), and Cross Tabulation. The results obtained from the data analysis show that teachers require professional knowledge and professional teaching skills, as well as a broad base of general knowledge (e.g., morality, service, cultural capital, institutional survey). Above all, in order to carry out instructional processes effectively, teachers should be both academically and professionally trained. This study revealed that teachers are not however expected to have an extraordinary memory, but rather looked upon as persons capable of thinking in the right direction. This study may provide a solution to the problem of teacher education and school effectiveness in Nigeria. For this reason, I offer this treatise to anyone seriously committed in improving schools in developing countries in general and in Nigeria in particular to improve the lives of all its citizens. In particular, I write this to encourage educational planners, education policy makers, curriculum developers, principals, teachers, and students of education interested in empirical information and methods to conceptualize the issue this study has raised and to provide them with useful suggestions to help them improve secondary schooling in Nigeria. Though, multiple audiences exist for any text. For this reason, I trust that the academic community will find this piece of work a useful addition to the existing literature on school effectiveness and school improvement. Through integrating concepts from a number of disciplines, I aim to describe as holistic a representation as space could allow of the components of school effectiveness and quality improvement. A new perspective on teachers' professional competencies, which not only take into consideration the unique characteristics of the variables used in this study, but also recommend their environmental and cultural derivation. In addition, researchers should focus their attention on the ways in which both professional and non-professional teachers construct and apply their methodological competencies, such as their grouping procedures and behaviors to the schooling of students. Keywords: Professional Training, Academic Training, Professionally Qualified, Academically Qualified, Professional Qualification, Academic Qualification, Job Effectiveness, Job Efficiency, Educational Planning, Teacher Training and Development, Nigeria.

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The main targets of human immunodeficiency virus (HIV) are CD4 receptors of CD4+ lymphocytes and many other cells such as monocytes/macrophages, megakaryocytes, peripheral blood dendritic cells, follicular dendritic cells (DC), epidermal Langerhans cells, and astrocytes. Infection and killing of CD4+ lymphocytes or false reaction of the body to HIV infection and the spontaneous apoptosis of CD4+ lymphocytes decrease CD4+ lymphocyte counts leading to immunosuppression, further disease progression, and appearance of opportunistic infections and malignancies. Oral manifestations are considered to be among the first signs of HIV infection. Enhanced degradation of extracellular matrix and basement membrane components in oral diseases including periodontitis is caused by Zn-dependent enzymes called matrix metalloproteinases (MMPs). The levels and degrees of activation of MMP-1, -2, -3, -7, -8, -9, -25, -26, tissue inhibitors of MMPs (TIMP)-1 and -2, and myeloperoxidase (MPO) and collagenolytic/gelatinolytic activities, and also Ig A, -G, and -M, total protein, and albumin levels in a two-year follow-up were studied from salivary samples. The expression of MMP-7, -8, -9, -25, and -26 immunoreactivities in gingival tissue specimens were studied. Healthy HIV-negative subjects served as controls. All studied clinical periodontal parameters and microbiological evaluation of the periodontopathogens showed that periodontal health of the HIV-positive patients was moderately decreased in comparison to the healthy controls. The levels of Candida in the periodontal pockets and salivary MPO increased with the severity of HIV infection. Immunoreactivities and levels of MMPs and TIMPs, and MMP activities (collagenase, gelatinase) were enhanced in the HIV-positive patient salivary samples relative to the healthy controls regardless of the phase of HIV infection. However, these parameters did not reflect periodontal status in a similar way as in the generally healthy periodontitis patients. Salivary total protein, albumin, IgA, -G, and -M levels were significantly higher in all phases of HIV infection compared to the controls, and salivary total protein, IgG and IgM levels remained higher after two years follow-up, partly correlating with the disease progression and which may reflect the leakage of serum components into the mouth and thus a decreased mucosal barrier. Salivary analyses of MMPs and TIMPs with immunohistochemical analyses showed that HIV infection could predispose to periodontal destruction when compared with healthy controls or the body s defence reactions associated with HIV infection may have been reflected or mediated by MMPs.

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The Vantaa Primary Care Depression Study (PC-VDS) is a naturalistic and prospective cohort study concerning primary care patients with depressive disorders. It forms a collaborative research project between the Department of Mental and Alcohol Research of the National Public Health Institute, and the Primary Health Care Organization of the City of Vantaa. The aim is to obtain a comprehensive view on clinically significant depression in primary care, and to compare depressive patients in primary care and in secondary level psychiatric care in terms of clinical characteristics. Consecutive patients (N=1111) in three primary care health centres were screened for depression with the PRIME-MD, and positive cases interviewed by telephone. Cases with current depressive symptoms were diagnosed face-to-face with the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I/P). A cohort of 137 patients with unipolar depressive disorders, comprising all patients with at least two depressive symptoms and clinically significant distress or disability, was recruited. The Structured Clinical Interview for DSM-IV Axis II Disorders (SCID-II), medical records, rating scales, interview and a retrospective life-chart were used to obtain comprehensive cross-sectional and retrospective longitudinal information. For investigation of suicidal behaviour the Scale for Suicidal Ideation (SSI), patient records and the interview were used. The methodology was designed to be comparable to The Vantaa Depression Study (VDS) conducted in secondary level psychiatric care. Comparison of major depressive disorder (MDD) patients aged 20-59 from primary care in PC-VDS (N=79) was conducted with new psychiatric outpatients (N =223) and inpatients (N =46) in VDS. The PC-VDS cohort was prospectively followed up at 3, 6 and 18 months. Altogether 123 patients (90%) completed the follow-up. Duration of the index episode and the timing of relapses or recurrences were examined using a life-chart. The retrospective investigation revealed current MDD in most (66%), and lifetime MDD in nearly all (90%) cases of clinically significant depressive syndromes. Two thirds of the “subsyndromal” cases had a history of major depressive episode (MDE), although they were currently either in partial remission or a potential prodromal phase. Recurrences and chronicity were common. The picture of depression was complicated by Axis I co-morbidity in 59%, Axis II in 52% and chronic Axis III disorders in 47%; only 12% had no co-morbidity. Within their lifetimes, one third (37%) had seriously considered suicide, and one sixth (17%) had attempted it. Suicidal behaviour clustered in patients with moderate to severe MDD, co-morbidity with personality disorders, and a history of treatment in psychiatric care. The majority had received treatment for depression, but suicidal ideation had mostly remained unrecognised. The comparison of patients with MDD in primary care to those in psychiatric care revealed that the majority of suicidal or psychotic patients were receiving psychiatric treatment, and the patients with the most severe symptoms and functional limitations were hospitalized. In other clinical aspects, patients with MDD in primary care were surprisingly similar to psychiatric outpatients. Mental health contacts earlier in the current MDE were common among primary care patients. The 18-month prospective investigation with a life-chart methodology verified the chronic and recurrent nature of depression in primary care. Only one-quarter of patients with MDD achieved and maintained full remission during the follow-up, while another quarter failed to remit at all. The remaining patients suffered either from residual symptoms or recurrences. While severity of depression was the strongest predictor of recovery, presence of co-morbid substance use disorders, chronic medical illness and cluster C personality disorders all contributed to an adverse outcome. In clinical decision making, beside severity of depression and co-morbidity, history of previous MDD should not be ignored by primary care doctors while depression there is usually severe enough to indicate at least follow-up, and concerning those with residual symptoms, evaluation of their current treatment. Moreover, recognition of suicidal behaviour among depressed patients should also be improved. In order to improve outcome of depression in primary care, the often chronic and recurrent nature of depression should be taken into account in organizing the care. According to literature management programs of a chronic disease, with enhancement of the role of case managers and greater integration of primary and specialist care, have been successful. Optimum ways of allocating resources between treatment providers as well as within health centres should be found.

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Background: Helicobacter pylori infection is usually acquired in early childhood and is rarely resolved spontaneously. Eradication therapy is currently recommended virtually to all patients. While the first and second therapies are prescribed without knowing the antibiotic resistance of the bacteria, it is important to know the primary resistance in the population. Aim: This study evaluates the primary resistance of H. pylori among patients in primary health care throughout Finland, the efficacy of three eradication regimens, the symptomatic response to successful therapy, and the effect of smoking on gastric histology and humoral response in H. pylori-positive patients. Patients and methods: A total of 23 endoscopy referral centres located throughout Finland recruited 342 adult patients with positive rapid urease test results, who were referred to upper gastrointestinal endoscopy from primary health care. Gastric histology, H. pylori resistance and H. pylori serology were evaluated. The patients were randomized to receive a seven-day regimen, comprising 1) lansoprazole 30 mg b.d., amoxicillin 1 g b.d. and metronidazole 400 mg t.d. (LAM), 2) lansoprazole 30 mg b.d., amoxicillin 1 g b.d. and clarithromycin 500 mg b.d. (LAC) or 3) ranitidine bismuth citrate 400 mg b.d., metronidazole 400 mg t.d. and tetracycline 500 mg q.d. (RMT). The eradication results were assessed, using the 13C-urea breath test 4 weeks after therapy. The patients completed a symptom questionnaire before and a year after the therapy. Results: Primary resistance of H. pylori to metronidazole was 48% among women and 25% among men. In women, metronidazole resistance correlated with previous use of antibiotics for gynaecologic infections and alcohol consumption. Resistance rate to clarithromycin was only 2%. Intention-to-treat cure rates of LAM, LAC, and RMT were 78%, 91% and 81%. While in metronidazole-sensitive cases the cure rates with LAM, LAC and RMT were similar, in metronidazole resistance LAM and RMT were inferior to LAC (53%, 67% and 84%). Previous antibiotic therapies reduced the efficacy of LAC, to the level of RMT. Dyspeptic symptoms in the Gastrointestinal Symptoms Rating Scale (GSRS) were decreased by 30.5%. In logistic regression analysis, duodenal ulcer, gastric antral neutrophilic inflammation and age from 50 to 59 years independently predicted greater decrease in dyspeptic symptoms. In the gastric body, smokers had milder inflammation and less atrophy and in the antrum denser H. pylori load. Smokers also had lower IgG antibody titres against H. pylori and a smaller proportional decrease in antibodies after successful eradication. Smoking tripled the risk of duodenal ulcers. Conclusions: in Finland H. pylori resistance to clarithromycin is low, but metronidazole resistance among women is high making metronidazole-based therapies unfavourable. Thus, LAC is the best choice for first-line eradication therapy. The effect of eradication on dyspeptic symptoms was only modest. Smoking slows the progression of atrophy in the gastric body.

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The purpose of the research was to determine how well Finnish pupils and students of different ages recognize plant species, which variables explain recognition of plant species, what plants and nature mean to the subjects and how plant species identification should be taught in general education in Finland. The subjects were pupils from: every class level of the primary schools (grades 1 6); lower- secondary school (grades 7 9); high school (grades I II); university departments of teacher education and classroom teachers and teachers from university involved with environmental teaching and also experts from education and botany. A total of 883 people took part in the research. Both quantitative and qualitative research methods were used. The quantitative methods were: a) plant species recognition test, where 70 plant species photos were shown to subjects and b) an experiment in which three experimental groups had a plant recognition test on the nature trail and the three comparison groups were tested on recognition of the same species in classroom. The testing materials consisted of 31 real plants outdoors and 31 photos taken of these real plant species that were shown to pupils from fourth, fifth and sixth classes (grade levels) from primary school. The qualitative methods were a questionnaire administered to pupils from elementary school and high school and students from the department of teacher education, to teachers from university and interviews, where 3 5 pupils and students who recognized the plant species best or worst in the recognition test were selected to be interviewed. Furthermore, classroom teachers from primary school and experts were interviewed. The research results showed that on average plant species were recognized insufficiently on every level of education. There was also variation between answers from primary school to university teachers. However, species recognition skills improved from primary school to university teachers. Among other things, sex and place of residence explained species recognition skills, because girls and pupils from rural areas knew plant species statistically significantly better than boys or pupil from cities. Almost every pupil, student and all classroom teachers wanted to recognize plant species better. Many pupils mentioned that a motivating teaching method would be to go outdoors and investigate the plant species themselves. University teachers and experts also mentioned that the best and most efficient learning and teaching method for species recognition skills, is to practice in nature. We should teach plant species in nature, using many senses and teaching methods. Also new technology could be used in teaching species recognition skills. Keywords: plant species recognition, plant species education, general education

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

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Surface proteolysis is important in migration of cells through tissue barriers. In the case of prokaryotes, surface proteolysis has been associated with invasiveness of pathogenic bacteria from the primary infection site into circulation and secondary infection sites in the host. This study addressed surface proteases of two important bacterial pathogens, Yersinia pestis which is the causative agent of the lethal systemic zoonosis, plague, and Salmonella enterica serovar Typhimurium which is an oral-faecal pathogen that annually causes millions of cases of gastoenteritis that may develop to septicaemia. Both bacterial species express an ortholog of the omptin family of transmembrane β-barrel, outer membrane proteases/adhesins. This thesis work addressed the functions of isolated plasminogen activator Pla of Y. pestis and the PgtE omptin of S. enterica. Pla and PgtE were isolated as His6-fusion proteins in denaturing conditions from recombinant Escherichia coli and activated by adding lipopolysaccharide (LPS). The structural features in LPS that enhance plasminogen activation by His6-Pla were determined, and it was found that the lack of O-specifi c chain, the presence of outer core oligosaccharide, the presence of phosphates in lipid A, as well as a low level of acylation in lipid A influence the enhancement of Pla activity by LPS. A conserved lipid A phosphate binding motif in Pla and PgtE was found important for the enhancement of enzymatic activity by LPS. The results help to explain the biological signifi cance of the genetic loss of the O-specifi c chain biosynthesis in Y. pestis as well as the variations in LPS structure upon entry of Y. pestis into the human host. Expression of Pla in Y. pestis is associated with adhesiveness to lamin of basement membranes. Here, isolated and LPS-activated His6-Pla was coated onto fluorescent microparticles. The coating conferred specifi c adhesiveness of the particles to laminin and reconstituted basement membrane, thus confi rming the intrinsic adhesive characteristics of the Pla protein. The adhesiveness is thought to direct plasmin proteolysis at tissue barriers, thus increasing tissue damage and bacterial spread. Gelatinase activity has not been previously reported in enteric bacteria. Expression of PgtE in S. enterica was associated with cleavage of porcine skin gelatin, denaturated human type I collagen, as well as DQ-gelatin. Purifi ed His6-PgtE also degraded porcine skin gelatin and human type I gelatin but did not react with DQ-gelatin, indicating that minor differences are seen in proteolysis by isolated and cell-bound PgtE. Pla was less effective in gelatin degradation. The novel gelatinase activity in S. enterica is likely to enhance bacterial dissemination during infection.

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Plants produce a diversity of secondary metabolites, i.e., low-molecular-weight compounds that have primarily ecological functions in plants. The flavonoid pathway is one of the most studied biosynthetic pathways in plants. In order to understand biosynthetic pathways fully, it is necessary to isolate and purify the enzymes of the pathways to study individual steps and to study the regulatory genes of the pathways. Chalcone synthases are key enzymes in the formation of several groups of flavonoids, including anthocyanins. In this study, a new chalcone synthase enzyme (GCHS4), which may be one of the main contributors to flower colour, was characterised from the ornamental plant Gerbera hybrida. In addition, four chalcone synthase-like genes and enzymes (GCHS17, GCHS17b, GCHS26 and GCHS26b) were studied. Spatial expression of the polyketide synthase gene family in gerbera was also analysed with quantitative RT-PCR from 12 tissues, including several developmental stages and flower types. A previously identified MYB transcription factor from gerbera, GMYB10, which regulates the anthocyanin pathway, was transferred to gerbera and the phenotypes were analysed. Total anthocyanin content and anthocyanidin profiles of control and transgenic samples were compared spectrophotometrically and with HPLC. The overexpression of GMYB10 alone was able to change anthocyanin pigmentation: cyanidin pigmentation was induced and pelargonidin pigmentation was increased. The gerbera 9K cDNA microarray was used to compare the gene expression profiles of transgenic tissues against the corresponding control tissues to reveal putative target genes for GMYB10. GMYB10 overexpression affected the expression of both early and late biosynthetic genes in anthocyanin-accumulating transgenic tissues, including the newly isolated gene GCHS4. Two new MYB domain factors, named as GMYB11 and GMYB12, were also upregulated. Gene transfer is not only a powerful tool for basic research, but also for plant breeding. However, crop improvement by genetic modification (GM) remains controversial, at least in Europe. Many of the concerns relating to both human health and to ecological impacts relate to changes in the secondary metabolites of GM crops. In the second part of this study, qualitative and quantitative differences in cytotoxicity and metabolic fingerprints between 225 genetically modified Gerbera hybrida lines and 42 non-GM Gerbera varieties were compared. There was no evidence for any major qualitative and quantitative changes between the GM lines and non-GM varieties. The developed cell viability assays offer also a model scheme for cell-based cytotoxicity screening of a large variety of GM plants in standardized conditions.

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The purpose of this research is to identify the optimal poverty policy for a welfare state. Poverty is defined by income. Policies for reducing poverty are considered primary, and those for reducing inequality secondary. Poverty is seen as a function of the income transfer system within a welfare state. This research presents a method for optimising this function for the purposes of reducing poverty. It is also implemented in the representative population sample within the Income Distribution Data. SOMA simulation model is used. The iterative simulation process is continued until a level of poverty is reached at which improvements can no longer be made. Expenditures and taxes are kept in balance during the process. The result consists of two programmes. The first programme (social assistance programme) was formulated using five social assistance parameters, all of which dealt with the norms of social assistance for adults (€/month). In the second programme (basic benefits programme), in which social assistance was frozen at the legislative level of 2003, the parameter with the strongest poverty reduction effect turned out to be one of the basic unemployment allowances. This was followed by the norm of the national pension for a single person, two parameters related to housing allowance, and the norm for financial aid for students of higher education institutions. The most effective financing parameter measured by gini-coefficient in all programmes was the percent of capital taxation. Furthermore, these programmes can also be examined in relation to their costs. The social assistance programme is significantly cheaper than the basic benefits programme, and therefore with regard to poverty, the social assistance programme is more cost effective than the basic benefits programme. Therefore, public demand for raising the level of basic benefits does not seem to correspond to the most cost effective poverty policy. Raising basic benefits has most effect on reducing poverty within the group of people whose basic benefits are raised. Raising social assistance, on the other hand, seems to have a strong influence on the poverty of all population groups. The most significant outcome of this research is the development of a method through which a welfare state’s income transfer-based safety net, which has severely deteriorated in recent decades, might be mended. The only way of doing so involves either social assistance or some forms of basic benefits and supplementing these by modifying social assistance.

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This study presents a population projection for Namibia for years 2011–2020. In many countries of sub-Saharan Africa, including Namibia, the population growth is still continuing even though the fertility rates have declined. However, many of these countries suffer from a large HIV epidemic that is slowing down the population growth. In Namibia, the epidemic has been severe. Therefore, it is important to assess the effect of HIV/AIDS on the population of Namibia in the future. Demographic research on Namibia has not been very extensive, and data on population is not widely available. According to the studies made, fertility has been shown to be generally declining and mortality has been significantly increasing due to AIDS. Previous population projections predict population growth for Namibia in the near future, yet HIV/AIDS is affecting the future population developments. For the projection constructed in this study, data on population is taken from the two most recent censuses, from 1991 and 2001. Data on HIV is available from HIV Sentinel Surveys 1992–2008, which test pregnant women for HIV in antenatal clinics. Additional data are collected from different sources and recent studies. The projection is made with software (EPP and Spectrum) specially designed for developing countries with scarce data. The projection includes two main scenarios which have different assumptions concerning the development of the HIV epidemic. In addition, two hypothetical scenarios are made: the first considering the case where HIV epidemic would never have existed and the second considering the case where HIV treatment would never have existed. The results indicate population growth for Namibia. Population in the 2001 census was 1.83 million and is projected to result in 2.38/2.39 million in 2020 in the first two scenarios. Without HIV, population would be 2.61 million and without treatment 2.30 million in 2020. Urban population is growing faster than rural. Even though AIDS is increasing mortality, the past high fertility rates still keep young adult age groups quite large. The HIV epidemic shows to be slowing down, but it is still increasing the mortality of the working-aged population. The initiation of HIV treatment in 2004 in the public sector seems to have had an effect on many projected indicators, diminishing the impact of HIV on the population. For example, the rise of mortality is slowing down.

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Aerosol particles have effect on climate, visibility, air quality and human health. However, the strength of which aerosol particles affect our everyday life is not well described or entirely understood. Therefore, investigations of different processes and phenomena including e.g. primary particle sources, initial steps of secondary particle formation and growth, significance of charged particles in particle formation, as well as redistribution mechanisms in the atmosphere are required. In this work sources, sinks and concentrations of air ions (charged molecules, cluster and particles) were investigated directly by measuring air molecule ionising components (i.e. radon activity concentrations and external radiation dose rates) and charged particle size distributions, as well as based on literature review. The obtained results gave comprehensive and valuable picture of the spatial and temporal variation of the air ion sources, sinks and concentrations to use as input parameters in local and global scale climate models. Newly developed air ion spectrometers (Airel Ltd.) offered a possibility to investigate atmospheric (charged) particle formation and growth at sub-3 nm sizes. Therefore, new visual classification schemes for charged particle formation events were developed, and a newly developed particle growth rate method was tested with over one year dataset. These data analysis methods have been widely utilised by other researchers since introducing them. This thesis resulted interesting characteristics of atmospheric particle formation and growth: e.g. particle growth may sometimes be suppressed before detection limit (~ 3 nm) of traditional aerosol instruments, particle formation may take place during daytime as well as in the evening, growth rates of sub-3 nm particles were quite constant throughout the year while growth rates of larger particles (3-20 nm in diameter) were higher during summer compared to winter. These observations were thought to be a consequence of availability of condensing vapours. The observations of this thesis offered new understanding of the particle formation in the atmosphere. However, the role of ions in particle formation, which is not well understood with current knowledge, requires further research in future.

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The purpose of the research was to determine how well Finnish children and youngsters in different ages recognize poisonous and eatable wild plant species and to which characteristics they pay attention to when identifying plants. The purpose was also to find out, how well the pupils and students can estimate if the wild plants are either poisonous or eatable. The goal was to gather knowledge about what factors explain these recognition and estimation skills. Also information was wanted about attitudes of children and youngsters towards recognizing and learning the poisonous and eatable wild plants. The research was made on subjects of 48 children and youngsters from grade 6 in primary school, grade 8 in lower- secondary school and vocational school. Both quantitative and qualitative methods were used. A plant recognition test, where 38 pictures on plants was presented, was made for the all subjects. The subjects were requested to name the plants and classify them to be either poisonous or eatable. In addition six students were interviewed from each class, altogether 18 subjects. The themes of the interviews were the attitudes towards eatable and poisonous wild plants and to learn to recognize species. During the interview pictures of plants were looked at and the subjects told which characteristics they pay attention to when trying to recognize it. The results showed that on average wild plants were recognized insufficiently. Standard variation in responses was large in all classes researched. The subjects got better results in classifying of the plants to be either poisonous or eatable than in naming the plants. This research shows that even when a subject cannot name a plant it is still possible for the subject to classify the plant to be either poisonous or eatable. Gender and being an immigrant explained the recognition skills of poisonous and eatable plants so that girls were somewhat better to recognize plant species and native Finns recognized poisonous and eatable plants better that immigrants. Age did not explain the skills to recognize species directly, since students in lower- secondary school recognized the poisonous and eatable plants better than primary school and vocational school students. In skills to estimate plants poisonous or eatability there was no difference according to gender, age, or immigrant background. The subjects considered the skills to recognize poisonous and eatable plants important. Learning to recognize plants at school was not considered interesting however. Since the recognition of plants in neighborhood belongs to tasks of general education it is important to think about how the teaching could be made interesting. According to findings of this study, especially the recognition of poisonous plants was considered important by the subjects. This knowledge as well as teaching about possibilities to utilize plants could be used as a way to motivate and teach the students. Avainsanat Nyckelord - Keywords Plant species recognition, recognition of poisonous plants, recognition of eatable plants, plant species education

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Snoring is a primary and major clinical symptom of upper airway obstruction during sleep. Sleep-disordered breathing ranges from primary snoring to significant partial upper airway obstruction, and obstructive sleep apnea. Adult snoring and obstructive sleep apnea have been extensively studied, whereas less is known about these disorders in children. Snoring and more severe obstructive sleep apnea have been shown to have a harmful effect on the neurobehavioral development of children, but the mechanisms of this effect remains unknown. Furthermore, the correlation of this effect to objective sleep study parameters remains poor. This study evaluated the prevalence of snoring in preschool-aged children in Finland. Host and environmental risk factors, and neurobehavioral and neurocognitive symptoms of children suffering from snoring or obstructive sleep apnea were also investigated. The feasibility of acoustic rhinometry in young children was assessed. The prevalence and risk factors of snoring (I) were evaluated by a questionnaire. The random sample included 2100 children aged 1-6 years living in Helsinki. All 3- to 6-year-old children whose parents reported their child to snore always, often, or sometimes were categorized as snorers, and invited to participate to the clinical study (II-IV). Non-snoring children whose parents were willing to participate in the clinical study were invited to serve as controls. Children underwent a clinical ear-nose-throat examination. Emotional, behavioral, and cognitive performances were evaluated by Child Behavioral Checklist (CBCL), Wechsler Preschool and Primary Scale of Intelligence (WPPSI-R) and NEPSY-A Developmental Neuropsychological Assessment (NEPSY). Nasal volume was measured by acoustic rhinometry, and nasal resistance by rhinomanometry. Lateral and posteroanterior cephalometry were performed. A standard overnight ambulatory polysomnography was performed in the home environment. Twenty-six healthy children were tested in order to assess the feasibility of acoustic rhinometry in young children (V). Snoring was common in children; 6.3% of children snored always or often, whereas 81.3% snored never or occasionally. No differences were apparent between snorers and non-snorers regarding age, or gender. Pediatric snoring was associated with recurrent upper respiratory infections, otitis media, and allergic rhinitis. Exposure to parental tobacco smoke, especially maternal smoking, was more common among snorers. Rhinitis was more common among children who exposured to tobacco smoke. Overnight polysomnography (PSG) was performed on 87 children; 74% showed no signs of significant upper airway obstruction during sleep. Three children had obstructive apnea/hypopnea index (OAHI) greater than 5/h. Age, gender, or a previous adenoidectomy or tonsillectomy did not correlate with OAHI, whereas tonsillar size did correlate with OAHI. Relative body weight and obesity correlated with none of the PSG parameters. In cephalometry, no clear differences or correlations were found in PSG parameters or between snorers and non-snorers. No correlations were observed between acoustic rhinometry, rhinomanometry, and PSG parameters. Psychiatric symptoms were more frequent in the snoring group than in the nonsnoring group. In particular, anxious and depressed symptoms were more prevalent in the snoring group. Snoring children frequently scored lower in language functions. However, PSG parameters correlated poorly with neurocognitive test results in these children. This study and previous studies indicate that snoring without episodes of obstructive apnea or SpO2 desaturations may cause impairment in behavioral and neurocognitive functions. The mechanism of action remains unknown. Exposure to parental tobacco smoke is more common among snorers than non-snorers, emphasizing the importance of a smoke-free environment. Children tolerated acoustic rhinometry measurements well.

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The aim of this study is to find out how urban segregation is connected to the differentiation in educational outcomes in public schools. The connection between urban structure and educational outcomes is studied on both the primary and secondary school level. The secondary purpose of this study is to find out whether the free school choice policy introduced in the mid-1990´s has an effect on the educational outcomes in secondary schools or on the observed relationship between the urban structure and educational outcomes. The study is quantitative in nature, and the most important method used is statistical regression analysis. The educational outcome data ranging the years from 1999 to 2002 has been provided by the Finnish National Board of Education, and the data containing variables describing the social and physical structure of Helsinki has been provided by Statistics Finland and City of Helsinki Urban Facts. The central observation is that there is a clear connection between urban segregation and differences in educational outcomes in public schools. With variables describing urban structure, it is possible to statistically explain up to 70 % of the variation in educational outcomes in the primary schools and 60 % of the variation in educational oucomes in the secondary schools. The most significant variables in relation to low educational outcomes in Helsinki are abundance of public housing, low educational status of the adult population and high numbers of immigrants in the school's catchment area. The regression model has been constructed using these variables. The lower coefficient of determination in the educational outcomes of secondary schools is mostly due to the effects of secondary school choice. Studying the public school market revealed that students selecting a secondary school outside their local catchment area cause an increase in the variation of the educational outcomes between secondary schools. When the number of students selecting a school outside their local catchment area is taken into account in the regressional model, it is possible to explain up to 80 % of the variation in educational outcomes in the secondary schools in Helsinki.

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The mitochondrion is an organelle of outmost importance, and the mitochondrial network performs an array of functions that go well beyond ATP synthesis. Defects in mitochondrial performance lead to diseases, often affecting nervous system and muscle. Although many of these mitochondrial diseases have been linked to defects in specific genes, the molecular mechanisms underlying the pathologies remain unclear. The work in this thesis aims to determine how defects in mitochondria are communicated within - and interpreted by - the cells, and how this contributes to disease phenotypes. Fumarate hydratase (FH) is an enzyme of the citrate cycle. Recessive defects in FH lead to infantile mitochondrial encephalopathies, while dominant mutations predispose to tumor formation. Defects in succinate dehydrogenase (SDH), the enzyme that precedes FH in the citrate cycle, have also been described. Mutations in SDH subunits SDHB, SDHC and SDHD are associated with tumor predisposition, while mutations in SDHA lead to a characteristic mitochondrial encephalopathy of childhood. Thus, the citrate cycle, via FH and SDH, seems to have essential roles in mitochondrial function, as well as in the regulation of processes such as cell proliferation, differentiation or death. Tumor predisposition is not a typical feature of mitochondrial energy deficiency diseases. However, defects in citrate cycle enzymes also affect mitochondrial energy metabolism. It is therefore necessary to distinguish what is specific for defects in citrate cycle, and thus possibly associated with the tumor phenotype, from the generic consequences of defects in mitochondrial aerobic metabolism. We used primary fibroblasts from patients with recessive FH defects to study the cellular consequences of FH-deficiency (FH-). Similarly to the tumors observed in FH- patients, these fibroblasts have very low FH activity. The use of primary cells has the advantage that they are diploid, in contrast with the aneuploid tumor cells, thereby enabling the study of the early consequences of FH- in diploid background, before tumorigenesis and aneuploidy. To distinguish the specific consequences of FH- from typical consequences of defects in mitochondrial aerobic metabolism, we used primary fibroblasts from patients with MELAS (mitochondrial encephalopathy with lactic acidosis and stroke-like episodes) and from patients with NARP (neuropathy, ataxia and retinitis pigmentosa). These diseases also affect mitochondrial aerobic metabolism but are not known to predispose to tumor formation. To study in vivo the systemic consequences of defects in mitochondrial aerobic metabolism, we used a transgenic mouse model of late-onset mitochondrial myopathy. The mouse contains a transgene with an in-frame duplication of a segment of Twinkle, the mitochondrial replicative helicase, whose defects underlie the human disease progressive external ophthalmoplegia. This mouse model replicates the phenotype in the patients, particularly neuronal degeneration, mitochondrial myopathy, and subtle decrease of respiratory chain activity associated with mtDNA deletions. Due to the accumulation of mtDNA deletions, the mouse was named deletor. We first studied the consequences of FH- and of respiratory chain defects for energy metabolism in primary fibroblasts. To further characterize the effects of FH- and respiratory chain malfunction in primary fibroblasts at transcriptional level, we used expression microarrays. In order to understand the in vivo consequences of respiratory chain defects in vivo, we also studied the transcriptional consequences of Twinkle defects in deletor mice skeletal muscle, cerebellum and hippocampus. Fumarate accumulated in the FH- homozygous cells, but not in the compound heterozygous lines. However, virtually all FH- lines lacked cytoplasmic FH. Induction of glycolysis was common to FH-, MELAS and NARP fibroblasts. In deletor muscle glycolysis seemed to be upregulated. This was in contrast with deletor cerebellum and hippocampus, where mitochondrial biogenesis was in progress. Despite sharing a glycolytic pattern in energy metabolism, FH- and respiratory chain defects led to opposite consequences in redox environment. FH- was associated with reduced redox environment, while MELAS and NARP displayed evidences of oxidative stress. The deletor cerebellum had transcriptional induction of antioxidant defenses, suggesting increased production of reactive oxygen species. Since the fibroblasts do not represent the tissues where the tumors appear in FH- patients, we compared the fibroblast array data with the data from FH- leiomyomas and normal myometrium. This allowed the determination of the pathways and networks affected by FH-deficiency in primary cells that are also relevant for myoma formation. A key pathway regulating smooth muscle differentiation, SRF (serum response factor)-FOS-JUNB, was found to be downregulated in FH- cells and in myomas. While in the deletor mouse many pathways were affected in a tissue-specific basis, like FGF21 induction in the deletor muscle, others were systemic, such as the downregulation of ALAS2-linked heme synthesis in all deletor tissues analyzed. However, interestingly, even a tissue-specific response of FGF21 excretion could elicit a global starvation response. The work presented in this thesis has contributed to a better understanding of mitochondrial stress signalling and of pathways interpreting and transducing it to human pathology.