8 resultados para LARGE NONCLINICAL SAMPLE

em Helda - Digital Repository of University of Helsinki


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In clinical settings impulsivity refers to a symptom of psychiatric disorder, but nonclinically oriented research treats impulsivity as a personality and temperament dimension. This prospective study examined whether impulsivity predicts adverse health-related behaviour and increased risk of health problems in a large, nonclinical sample of 5433 subjects working in 12 Finnish hospitals. The data were collected using two questionnaire surveys at a 2-year interval. After controlling for alcohol use at baseline, higher impulsivity predicted increased alcohol consumption at follow-up in both genders (p < .01) and was associated with increased likelihood of becoming a heavy drinker or taking up smoking (p < .05). Impulsivity also predicted an increased number of cigarettes smoked per day in the follow-up among women (p < .001), but not among men, although adjustment for the number of cigarettes smoked at baseline attenuated these associations (p = .08 for women). In men, higher impulsivity was associated with shorter sleep duration and waking up several times per night independent of baseline characteristics (p < .01), whereas in women, higher impulsivity predicted difficulty in falling asleep and waking up feeling tired after the usual amount of sleep (p < .05). In women, these associations became nonsignificant after adjustment for pre-existing somatic and psychiatric diseases. Finally, higher impulsivity was associated with an increased 2-year incidence of physician-diagnosed peptic ulcer disease (adjusted odds ratio (OR) = 2.42, 95% confidence interval (CI) = 1.21 - 4.82) and onset of depression (OR = 1.95, 95% CI = 1.28 - 2.97) after adjustment for a variety of baseline covariates. In conclusion, this study shows that in a nonclinical population, impulsivity appears to be a risk factor for various unhealthy behaviour and health problems.

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During the past ten years, large-scale transcript analysis using microarrays has become a powerful tool to identify and predict functions for new genes. It allows simultaneous monitoring of the expression of thousands of genes and has become a routinely used tool in laboratories worldwide. Microarray analysis will, together with other functional genomics tools, take us closer to understanding the functions of all genes in genomes of living organisms. Flower development is a genetically regulated process which has mostly been studied in the traditional model species Arabidopsis thaliana, Antirrhinum majus and Petunia hybrida. The molecular mechanisms behind flower development in them are partly applicable in other plant systems. However, not all biological phenomena can be approached with just a few model systems. In order to understand and apply the knowledge to ecologically and economically important plants, other species also need to be studied. Sequencing of 17 000 ESTs from nine different cDNA libraries of the ornamental plant Gerbera hybrida made it possible to construct a cDNA microarray with 9000 probes. The probes of the microarray represent all different ESTs in the database. From the gerbera ESTs 20% were unique to gerbera while 373 were specific to the Asteraceae family of flowering plants. Gerbera has composite inflorescences with three different types of flowers that vary from each other morphologically. The marginal ray flowers are large, often pigmented and female, while the central disc flowers are smaller and more radially symmetrical perfect flowers. Intermediate trans flowers are similar to ray flowers but smaller in size. This feature together with the molecular tools applied to gerbera, make gerbera a unique system in comparison to the common model plants with only a single kind of flowers in their inflorescence. In the first part of this thesis, conditions for gerbera microarray analysis were optimised including experimental design, sample preparation and hybridization, as well as data analysis and verification. Moreover, in the first study, the flower and flower organ-specific genes were identified. After the reliability and reproducibility of the method were confirmed, the microarrays were utilized to investigate transcriptional differences between ray and disc flowers. This study revealed novel information about the morphological development as well as the transcriptional regulation of early stages of development in various flower types of gerbera. The most interesting finding was differential expression of MADS-box genes, suggesting the existence of flower type-specific regulatory complexes in the specification of different types of flowers. The gerbera microarray was further used to profile changes in expression during petal development. Gerbera ray flower petals are large, which makes them an ideal model to study organogenesis. Six different stages were compared and specifically analysed. Expression profiles of genes related to cell structure and growth implied that during stage two, cells divide, a process which is marked by expression of histones, cyclins and tubulins. Stage 4 was found to be a transition stage between cell division and expansion and by stage 6 cells had stopped division and instead underwent expansion. Interestingly, at the last analysed stage, stage 9, when cells did not grow any more, the highest number of upregulated genes was detected. The gerbera microarray is a fully-functioning tool for large-scale studies of flower development and correlation with real-time RT-PCR results show that it is also highly sensitive and reliable. Gene expression data presented here will be a source for gene expression mining or marker gene discovery in the future studies that will be performed in the Gerbera Laboratory. The publicly available data will also serve the plant research community world-wide.

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The human resource (HR) function is under pressure both to change roles and to play a large variety of roles. Questions of change and development in the HR function become particularly interesting in the context of mergers and acquisitions when two corporations are integrated. The purpose of the thesis is to examine the roles played by the HR function in the context of large-scale mergers and thus to understand what happens to the HR function in such change environments, and to shed light on the underlying factors that influence changes in the HR function. To achieve this goal, the study seeks first to identify the roles played by the HR function before and after the merger, and second, to identify the factors that affect the roles played by the HR function. It adopts a qualitative case study approach including ten focal case organisations (mergers) and four matching cases (non-mergers). The sample consists of large corporations originating from either Finland or Sweden. HR directors and members of the top management teams within the case organisations were interviewed. The study suggests that changes occur within the HR function, and that the trend is for the HR function to become increasingly strategic. However, the HR function was found to play strategic roles only when the HR administration ran smoothly. The study also suggests that the HR function has become more versatile. An HR function that was perceived to be mainly administrative before the merger is likely after the merger to perform some strategically important activities in addition to the administrative ones. Significant changes in the roles played by the HR function were observed in some of the case corporations. This finding suggests that the merger integration process is a window of opportunity for the HR function. HR functions that take a proactive and leading role during the integration process might expand the number of roles played and move from being an administrator before the merger to also being a business partner after integration. The majority of the HR functions studied remained mainly reactive during the organisational change process and although the evidence showed that they moved towards strategic tasks, the intra-functional changes remained comparatively small in these organisations. The study presents a new model that illustrates the impact of the relationship between the top management team and the HR function on the role of the HR function. The expectations held by the top management team for the HR function and the performance of the HR function were found to interact. On a dimension reaching from tactical to strategic, HR performance is likely to correspond to the expectations held by top management.

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The concept of vascular cognitive impairment (VCI) covers a wide spectrum of cognitive dysfunctions related to cerebrovascular disease. Among the pathophysiological determinants of VCI are cerebral stroke, white matter lesions and brain atrophy, which are known to be important risk factors for dementia. However, the specific mechanisms behind the brain abnormalities and cognitive decline are still poorly understood. The present study investigated the neuropsychological correlates of particular magnetic resonance imaging (MRI) findings, namely, medial temporal lobe atrophy (MTA), white matter hyperintensities (WMH), general cortical atrophy and corpus callosum (CC) atrophy in subjects with cerebrovascular disease. Furthermore, the cognitive profile of subcortical ischaemic vascular disease (SIVD) was examined. This study was conducted as part of two large multidisciplinary study projects, the Helsinki Stroke Aging Memory (SAM) Study and the multinational Leukoaraiosis and Disability (LADIS) Study. The SAM cohort consisted of 486 patients, between 55 and 85 years old, with ischaemic stroke from the Helsinki University Hospital, Helsinki, Finland. The LADIS Study included a mixed sample of subjects (n=639) with age-related WMH, between 65 and 84 years old, gathered from 11 centres around Europe. Both studies included comprehensive clinical and neuropsychological assessments and detailed brain MRI. The relationships between the MRI findings and the neuropsychological test performance were analysed by controlling for relevant confounding factors such as age, education and other coexisting brain lesions. The results revealed that in elderly patients with ischaemic stroke, moderate to severe MTA was specifically related to impairment of memory and visuospatial functions, but mild MTA had no clinical relevance. Instead, WMH were primarily associated with executive deficits and mental slowing. These deficits mediated the relationship between WMH and other, secondary cognitive deficits. Cognitive decline was best predicted by the overall degree of WMH, whereas the independent contribution of regional WMH measures was low. Executive deficits were the most prominent cognitive characteristic in SIVD. Compared to other stroke patients, the patients with SIVD also presented more severe memory deficits, which were related to MTA. The cognitive decline in SIVD occurred independently of depressive symptoms and, relative to healthy control subjects, it was substantial in severity. In stroke patients, general cortical atrophy also turned out to be a strong predictor of cognitive decline in a wide range of cognitive domains. Moreover, in elderly subjects with WMH, overall CC atrophy was related to reduction in mental speed, while anterior CC atrophy was independently associated with frontal lobe-mediated executive functions and attention. The present study provides cross-sectional evidence for the involvement of WMH, MTA, general cortical atrophy and CC atrophy in VCI. The results suggest that there are multifaceted pathophysiological mechanisms behind VCI in the elderly, including both vascular ischaemic lesions and neurodegenerative changes. The different pathological changes are highly interrelated processes and together they may produce cumulative effects on cognitive decline.

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Background. Evidence of cognitive dysfunction in depressive and anxiety disorders is growing. However, the neuropsychological profile of young adults has received only little systematic investigation, although depressive and anxiety disorders are major public health problems for this age group. Available studies have typically failed to account for psychiatric comorbidity, and samples derived from population-based settings have also seldom been investigated. Burnout-related cognitive functioning has previously been investigated in only few studies, again all using clinical samples and wide age groups. Aims. Based on the information gained by conducting a comprehensive review, studies on cognitive impairment in depressive and anxiety disorders among young adults are rare. The present study examined cognitive functioning in young adults with a history of unipolar depressive or anxiety disorders in comparison to healthy peers, and associations of current burnout symptoms with cognitive functioning, in a population-based setting. The aim was also to determine whether cognitive deficits vary as a function of different disorder characteristics, such as severity, psychiatric comorbidity, age at onset, or the treatments received. Methods. Verbal and visual short-term memory, verbal long-term memory and learning, attention, psychomotor processing speed, verbal intelligence, and executive functioning were measured in a population-based sample of 21-35 year olds. Performance was compared firstly between participants with pure non-psychotic depression (n=68) and healthy peers (n=70), secondly between pure (n=69) and comorbid depression (n=57), and thirdly between participants with anxiety disorders (n=76) and healthy peers (n=71). The diagnostic procedure was based on the SCID interview. Fourthly, the associations of current burnout symptoms, measured with the Maslach Burnout Inventory General Survey, and neuropsychological test performance were investigated among working young adults (n=225). Results. Young adults with depressive or anxiety disorders, with or without psychiatric comorbidity, were not found to have major cognitive impairments when compared to healthy peers. Only mildly compromised verbal learning was found among depressed participants. Pure and comorbid depression groups did not differ in cognitive functioning, either. Among depressed participants, those who had received treatment showed more impaired verbal memory and executive functioning, and earlier onset corresponded with more impaired executive functioning. In anxiety disorders, psychotropic medication and low psychosocial functioning were associated with deficits in executive functioning, psychomotor processing speed, and visual short-term memory. Current burnout symptoms were associated with better performance in verbal working memory and verbal intelligence. However, lower examiner-rated social and occupational functioning was associated with problems in verbal attention, memory, and learning. Conclusions. Depression, anxiety disorders, or burnout symptoms may not be associated with major cognitive deficits among young adults derived from the general population. Even psychiatric comorbidity may not aggravate cognitive functioning in depressive or anxiety disorders among these young adults. However, treatment-seeking in depression was found to be associated with cognitive deficits, suggesting that these deficits relate to increased distress. Additionally, early-onset depression, found to be associated with executive dysfunction, may represent a more severe form of the disorder. In anxiety disorders, those with low symptom-related psychosocial functioning may have cognitive impairment. An association with self-reported burnout symptoms and cognitive deficits was not detected, but individuals with low social and occupational functioning may have impaired cognition.

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The aim of this dissertation was to explore teaching in higher education from the teachers’ perspective. Two of the four studies analysed the effect of pedagogical training on approaches to teaching and on self-efficacy beliefs of teachers on teaching. Of these two studies, Study I analysed the effect of pedagogical training by applying a cross-sectional setting. The results showed that short training made teachers less student-centred and decreased their self-efficacy beliefs, as reported by the teachers themselves. However, more constant training enhanced the adoption of a student-centred approach to teaching and increased the self-efficacy beliefs of teachers as well. The teacher-focused approach to teaching was more resistant to change. Study II, on the other hand, applied a longitudinal setting. The results implied that among teachers who had not acquired more pedagogical training after Study II there were no changes in the student-focused approach scale between the measurements. However, teachers who had participated in further pedagogical training scored significantly higher on the scale measuring the student-focused approach to teaching. There were positive changes in the self-efficacy beliefs of teachers among teachers who had not participated in further training as well as among those who had. However, the analysis revealed that those teachers had the least teaching experience. Again, the teacher-focused approach was more resistant to change. Study III analysed approaches to teaching qualitatively by using a large and multidisciplinary sample in order to capture the variation in descriptions of teaching. Two broad categories of description were found: the learning-focused and the content-focused approach to teaching. The results implied that the purpose of teaching separates the two categories. In addition, the study aimed to identify different aspects of teaching in the higher-education context. Ten aspects of teaching were identified. While Study III explored teaching on a general level, Study IV analysed teaching on an individual level. The aim was to explore consonance and dissonance in the kinds of combinations of approaches to teaching university teachers adopt. The results showed that some teachers were clearly and systematically either learning- or content-focused. On the other hand, profiles of some teachers consisted of combinations of learning- and content-focused approaches or conceptions making their profiles dissonant. Three types of dissonance were identified. The four studies indicated that pedagogical training organised for university teachers is needed in order to enhance the development of their teaching. The results implied that the shift from content-focused or dissonant profiles towards consonant learning-focused profiles is a slow process and that teachers’ conceptions of teaching have to be addressed first in order to promote learning-focused teaching.

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This cross-sectional study analyzed psychological well-being at school using the Self-Determination theory as a theoretical frame-work. The study explored basic psychological needs fulfillment (BPNS), academic (SRQ-A), prosocial self-regulation (SRQ-P) and motivation, and their relationship with achievement in general, special and selective education (N=786, 444 boys, 345 girls, mean age 12 yrs 8 mths). Motivation starts behavior which becomes guided by self-regulation. The perceived locus of control (PLOC) affects how self-determined this behavior will be; in other words, to what extent it is autonomously regulated. In order learn and thus to be able to accept external goals, a student has to feel emotionally safe and have sufficient ego-flexibility—all of which builds on satisfied psychological needs. In this study those conditions were explored. In addition to traditional methods Self-organizing maps (SOM), was used in order to cluster the students according to their well-being, self-regulation, motivation and achievement scores. The main impacts of this research were: a presentation of the theory based alternative of studying psychological well-being at school and usage of both the variable and person-oriented approach. In this Finnish sample the results showed that the majority of students felt well, but the well-being varied by group. Overall about for 11–15% the basic needs were deprived depending on the educational group. Age and educational group were the most effective factors; gender was important in relation to prosocial identified behavior. Although the person-oriented SOM-approach, was in a large extent confirming what was no-ticed by using comparison of the variables: the SEN groups had lower levels of basic needs fulfillment and less autonomous self-regulation, interesting deviations of that rule appeared. Some of the SEL- and GEN-group members ended up in the more unfavorable SOM-clusters, and not all SEN-group members belonged to the poorest clusters (although not to the best either). This evidence refines the well-being and self-regulation picture, and may re-direct intervention plans, and turn our focus also on students who might otherwise remain unnoticed. On the other hand, these results imply simultaneously that in special education groups the average is not the whole truth. On the basis of theoretical and empirical considerations an intervention model was sug-gested. The aim of the model was to shift amotivation or external motivation in a more intrinsic direction. According to the theoretical and empirical evidence this can be achieved first by studying the self-concept a student has, and then trying to affect both inner and environmental factors—including a consideration of the basic psychological needs. Keywords: academic self-regulation, prosocial self-regulation, basic psychological needs, moti-vation, achievement

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The basic goal of a proteomic microchip is to achieve efficient and sensitive high throughput protein analyses, automatically carrying out several measurements in parallel. A protein microchip would either detect a single protein or a large set of proteins for diagnostic purposes, basic proteome or functional analysis. Such analyses would include e.g. interactomics, general protein expression studies, detecting structural alterations or secondary modifications. Visualization of the results may occur by simple immunoreactions, general or specific labelling, or mass spectrometry. For this purpose we have manufactured chip-based proteome analysis devices that utilize the classical polymer gel electrophoresis technology to run one and two-dimensional gel electrophoresis separations of proteins in just a smaller size. In total, we manufactured three functional prototypes of which one performed a miniaturized one-dimensional gel electrophoresis (1-DE) separation, the second and third preformed two-dimensional gel electrophoresis (2-DE) separations. These microchips were successfully used to separate and characterize a set of predefined standard proteins, cell and tissue samples. Also, the miniaturized 2-DE (ComPress-2DE) chip presents a novel way of combining the 1st and 2nd dimensional separations, thus avoiding manual handling of the gels, eliminate cross-contamination, and make analyses faster and repeatability better. They all showed the advantages of miniaturization over the commercial devices; such as fast analysis, low sample- and reagent consumption, high sensitivity, high repeatability and inexpensive performance. All these instruments have the potential to be fully automated due to their easy-to-use set-up.