7 resultados para Konsekvenser

em Helda - Digital Repository of University of Helsinki


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The aim of the study was to explore why the MuPSiNet project - a computer and network supported learning environment for the field of health care and social work - did not develop as expected. To grasp the problem some hypotheses were formulated. The hypotheses regarded the teachers' skills in and attitudes towards computing and their attitudes towards constructivist study methods. An online survey containing 48 items was performed. The survey targeted all the teachers within the field of health care and social work in the country, and it produced 461 responses that were analysed against the hypotheses. The reliability of the variables was tested using the Cronbach alpha coefficient and t-tests. Poor basic computing skills among the teachers combined with a vulnerable technical solution, and inadequate project management combined with lack of administrative models for transforming economic resources into manpower were the factors that turned out to play a decisive role in the project. Other important findings were that the teachers had rather poor skills and knowledge in computing, computer safety and computer supported instruction, and that these skills were significantly poorer among female teachers who were in majority in the sample. The fraction of teachers who were familiar with software for electronic patient records (EPR) was low. The attitudes towards constructivist teaching methods were positive, and further education seemed to utterly increase the teachers' readiness to use alternative teaching methods. The most important conclusions were the following: In order to integrate EPR software as a natural tool in teaching planning and documenting health care, it is crucial that the teachers have sufficient basic skills in computing and that more teachers have personal experience of using EPR software. In order for computer supported teaching to become accepted it is necessary to arrange with extensive further education for the teachers presently working, and for that further education to succeed it should be backed up locally among other things by sufficient support in matters concerning computer supported teaching. The attitudes towards computing showed significant gender differences. Based on the findings it is suggested that basic skills in computing should also include an awareness of data safety in relation to work in different kinds of computer networks, and that projects of this kind should be built up around a proper project organisation with sufficient resources. Suggestions concerning curricular development and further education are also presented. Conclusions concerning the research method were that reminders have a better effect, and that respondents tend to answer open-ended questions more verbosely in electronically distributed online surveys compared to traditional surveys. A method of utilising randomized passwords to guarantee respondent anonymity while maintaining sample control is presented. Keywords: computer-assisted learning, computer-assisted instruction, health care, social work, vocational education, computerized patient record, online survey

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Life-history theory states that although natural selection would favour a maximisation of both reproductive output and life-span, such a combination can not be achieved in any living organism. According to life-history theory the reason for the fact that not all traits can be maximised simultaneously is that different traits compete with each other for resources. These relationships between traits that constrain the simultaneous evolution of two or more traits are called trade-offs. Therefore, during different life-stages an individual needs to optimise its allocation of resources to life-history components such as growth, reproduction and survival. Resource limitation acts on these traits and therefore investment in one trait, e.g. reproduction, reduces the resources available for investment in another trait, e.g. residual reproduction or survival. In this thesis I study how food resources during different stages of the breeding event affect reproductive decisions in the Ural owl (Strix uralensis) and the consequences of these decisions on parents and offspring. The Ural owl is a suitable study species for such studies in natural populations since they are long-lived, site-tenacious, and feed on voles. The vole populations in Fennoscandia fluctuate in three- to four-year cycles, which create a variable food environment for the Ural owls to cope with. The thesis gives new insight in reproductive costs and their consequences in natural animal populations with emphasis on underlying physiological mechanisms. I found that supplementary fed Ural owl parents invest supplemented food resources during breeding in own self-maintenance instead of allocating those resources to offspring growth. This investment in own maintenance instead of improving current reproduction had carry-over effects to the following year in terms of increased reproductive output. Therefore, I found evidence that reduced reproductive costs improves future reproductive performance. Furthermore, I found evidence for the underlying mechanism behind this carry-over effect of supplementary food on fecundity. The supplementary-fed parents reduced their feeding investment in the offspring compared to controls, which enabled the fed female parents to invest the surplus resources in parasite resistance. Fed female parents had lower blood parasite loads than control females and this effect lasted until the following year when also reproductive output was increased. Hence, increased investment in parasite resistance when resources are plentiful has the potential to mediate positive carry-over effects on future reproduction. I further found that this carry-over effect was only present when potentials for future reproduction were good. The thesis also provides new knowledge on resource limitation on maternal effects. I found that increased resources prior to egg laying improve the condition and health of Ural owl females and enable them to allocate more resources to reproduction than control females. These additional resources are not allocated to increase the number of offspring, but instead to improve the quality of each offspring. Fed Ural owl females increased the size of their eggs and allocated more health improving immunological components into the eggs. Furthermore, the increased egg size had long-lasting effects on offspring growth, as offspring from larger eggs were heavier at fledging. Limiting resources can have different short- and long-term consequences on reproductive decisions that affect both offspring number and quality. In long-lived organisms, such as the Ural owl, it appears to be beneficial in terms of fitness to invest in long breeding life-span instead of additional investment in current reproduction. In Ural owls, females can influence the phenotypic quality of the offspring by transferring additional resources to the eggs that can have long-lasting effects on growth.

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Herbivorous insects comprise a major part of terrestrial biodiversity, and their interactions with their host plants and natural enemies are of vast ecological importance. A large body of research demonstrates that the ecology and evolution of these insects may be affected by trophic interactions, by abiotic influences, and by intraspecific processes, but so far research on these individual aspects has rarely been combined. This thesis uses the leaf-mining moth Tischeria ekebladella and the pedunculate oak (Quercus robur) as a case study to assess how spatial variation in trophic interactions and the physical distribution of host trees jointly affect the distribution, dynamics and evolution of a host-specific herbivore. With respect to habitat quality, Tischeria ekebladella experiences abundant variation at several spatial scales. Most of this variation occurs at small scales notably among leaves and shoots within individual trees. While hypothetically this could cause moths to evolve an ability to select leaves and shoots of high quality, I did not find any coupling between female preference and offspring performance. Based on my studies on temporal variation in resource quality I therefore propose that unpredictable temporal changes in the relative rankings of individual resource units may render it difficult for females to predict the fate of their developing offspring. With respect to intraspecific processes, my results suggest that limited moth dispersal in relation to the spatial distribution of oak trees plays a key role in determining the regional distribution of Tischeria ekebladella. The distribution of the moth is aggregated at the landscape level, where local leaf miner populations are less likely to be present where oaks are scarce. A modelling exercise based on empirical dispersal estimates revealed that the moth population on Wattkast an island in south-western Finland is spatially structured overall, but that the relative importance of local and regional processes on tree-specific moth dynamics varies drastically across the landscape. To conclude, my work in the oak-Tischeria ekebladella system demonstrates that the local abundance and regional distribution of a herbivore may be more strongly influenced by the spatial location of host trees than by their relative quality. Hence, it reveals the importance of considering spatial context in the study of herbivorous insects, and forms a bridge between the classical fields of plant-insect interactions and spatial ecology.

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Social groups are common across animal species. The reasons for grouping are straightforward when all individuals gain directly from cooperating. However, the situation becomes more complex when helping entails costs to the personal reproduction of individuals. Kin selection theory has offered a fruitful framework to explain such cooperation by stating that individuals may spread their genes not only through their own reproduction, but also by helping related individuals reproduce. However, kin selection theory also implicitly predicts conflicts when groups consist of non-clonal individuals, i.e. relatedness is less than one. Then, individual interests are not perfectly aligned, and each individual is predicted to favour the propagation of their own genome over others. Social insects provide a solid study system to study the interplay between cooperation and conflict. Breeding systems in social insects range from solitary breeding to eusocial colonies displaying complete division of reproduction between the fertile queen and the sterile worker caste. Within colonies, additional variation is provided by the presence of several reproductive individuals. In many species, the queen mates multiply, which causes the colony to consist of half-sib instead of full-sib offspring. Furthermore, in many species colonies contain multiple breeding queens, which further dilutes relatedness between colony members. Evolutionary biology is thus faced with the challenge to answer why such variation in social structure exists, and what the consequences are on the individual and population level. The main part of this thesis takes on this challenge by investing the dynamics of socially polymorphic ant colonies. The first four chapters investigate the causes and consequences of different social structures, using a combination of field studies, genetic analyses and laboratory experiments. The thesis ends with a theoretical chapter focusing on different social interactions (altruism and spite), and the evolution of harming traits. The main results of the thesis show that social polymorphism has the potential to affect the behaviour and traits of both individuals and colonies. For example, we found that genetic polymorphism may increase the phenotypic variation between individuals in colonies, and that socially polymorphic colonies may show different life history patterns. We also show that colony cohesion may be enhanced even in multiple-queen colonies through patterns of unequal reproduction between queens. However, the thesis also demonstrates that spatial and temporal variation between both populations and environments may affect individual and colony traits, to the degree that results obtained in one place or at one time may not be applicable in other situations. This opens up potential further areas of research to explain these differences.

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Defects in mitochondrial DNA (mtDNA) maintenance cause a range of human diseases, including autosomal dominant progressive external ophthalmoplegia (adPEO). This study aimed to clarify the molecular background of adPEO. We discovered that deoxynucleoside triphosphate (dNTP) metabolism plays a crucial in mtDNA maintenance and were thus prompted to search for therapeutic strategies based on the modulation of cellular dNTP pools or mtDNA copy number. Human mtDNA is a 16.6 kb circular molecule present in hundreds to thousands of copies per cell. mtDNA is compacted into nucleoprotein clusters called nucleoids. mtDNA maintenance diseases result from defects in nuclear encoded proteins that maintain the mtDNA. These syndromes typically afflict highly differentiated, post-mitotic tissues such as muscle and nerve, but virtually any organ can be affected. adPEO is a disease where mtDNA molecules with large-scale deletions accumulate in patients tissues, particularly in skeletal muscle. Mutations in five nuclear genes, encoding the proteins ANT1, Twinkle, POLG, POLG2 and OPA1, have previously been shown to cause adPEO. Here, we studied a large North American pedigree with adPEO, and identified a novel heterozygous mutation in the gene RRM2B, which encodes the p53R2 subunit of the enzyme ribonucleotide reductase (RNR). RNR is the rate-limiting enzyme in dNTP biosynthesis, and is required both for nuclear and mitochondrial DNA replication. The mutation results in the expression of a truncated form of p53R2, which is likely to compete with the wild-type allele. A change in enzyme function leads to defective mtDNA replication due to altered dNTP pools. Therefore, RRM2B is a novel adPEO disease gene. The importance of adequate dNTP pools and RNR function for mtDNA maintenance has been established in many organisms. In yeast, induction of RNR has previously been shown to increase mtDNA copy number, and to rescue the phenotype caused by mutations in the yeast mtDNA polymerase. To further study the role of RNR in mammalian mtDNA maintenance, we used mice that broadly overexpress the RNR subunits Rrm1, Rrm2 or p53R2. Active RNR is a heterotetramer consisting of two large subunits (Rrm1) and two small subunits (either Rrm2 or p53R2). We also created bitransgenic mice that overexpress Rrm1 together with either Rrm2 or p53R2. In contrast to the previous findings in yeast, bitransgenic RNR overexpression led to mtDNA depletion in mouse skeletal muscle, without mtDNA deletions or point mutations. The mtDNA depletion was associated with imbalanced dNTP pools. Furthermore, the mRNA expression levels of Rrm1 and p53R2 were found to correlate with mtDNA copy number in two independent mouse models, suggesting nuclear-mitochondrial cross talk with regard to mtDNA copy number. We conclude that tight regulation of RNR is needed to prevent harmful alterations in the dNTP pool balance, which can lead to disordered mtDNA maintenance. Increasing the copy number of wild-type mtDNA has been suggested as a strategy for treating PEO and other mitochondrial diseases. Only two proteins are known to cause a robust increase in mtDNA copy number when overexpressed in mice; the mitochondrial transcription factor A (TFAM), and the mitochondrial replicative helicase Twinkle. We studied the mechanisms by which Twinkle and TFAM elevate mtDNA levels, and showed that Twinkle specifically implements mtDNA synthesis. Furthermore, both Twinkle and TFAM were found to increase mtDNA content per nucleoid. Increased mtDNA content in mouse tissues correlated with an age-related accumulation of mtDNA deletions, depletion of mitochondrial transcripts, and progressive respiratory dysfunction. Simultaneous overexpression of Twinkle and TFAM led to a further increase in the mtDNA content of nucleoids, and aggravated the respiratory deficiency. These results suggested that high mtDNA levels have detrimental long-term effects in mice. These data have to be considered when developing and evaluating treatment strategies for elevating mtDNA copy number.

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Bakgrunden till denna undersökning utgörs av arbetslivets förändring och dess konsekvenser för konstrueringen av självidentiteten; hur avväger unga konsulter i början av sin karriär mellan olika diskurser för att skapa en förhandlad självidentitet som styrs av idén om en karriär och såvida är hållbar även i ett långtidsperspektiv? Undersökningen tar avstamp i de sociologiska diskussionerna om informationssamhällets framväxt och dess inverkan på arbetets karaktär. Undersökningen utgår från begreppet kunskapsarbete (Alvesson 2001; Blom, Melin & Pyöriä 2001) eftersom konsultyrket kan anses representera denna typ av arbete. Ett genomgående tema är flexibiliteten och det höga tempot som å ena sidan möjliggör självförverkligande men å andra sidan försvårar skapandet av en sammanhängande självidentitet (Sennett 2002). Denna problematik är viktigt att ta i beaktande då förlängandet av arbetskarriärerna och ökandet av arbetslivets attraktivitet blivit centrala mål för den finska samhällspolitiken (Julkunen & Pärnänen 2005) samtidigt som ett generationsskifte håller på att ske på den finländska arbetsmarknaden. Undersökningen utgår från idén om karriären som ett manuskript som ger upphov för identitetsförhandlingar och sammanbinder livets olika domäner till ett personligt liv inte bara i nuläget utan även i ett långtidsperspektiv. Enligt Alvesson & Willmot (2002) framkallas identitetsförhandlingar genom både samhälleliga och organisationsspecifika identitetsreglerande praktiker. Jag utgår från antagandet att självidentiteten fungerar som den sammanbindande knytpunkten mellan karriären och det övriga livet, vilket gör det intressant att koncentrera sig på de identitetsförhandlingar som informanterna utsätts för i förhållande till sitt arbete och idén om en karriär. Begreppet personligt liv ger utrymme för individuell aktivitet och personliga betydelser men behåller ändå föreställningen om individen som inbäddad och sammanbunden i och med det sociala och kulturella (Smart 2007). I bakgrunden finns teorierna om den nya form som makten antagit i organisationer (Foucault; Rose 1999; Grey 1994, Casey 1995) och förvandlat individen till en ett självstyrande subjekt som arbetar som en entreprenör (Rose 1999). Jag poängterar den subjektiva aspekten av karriären som någonting som individen själv konstruerar (Hughes 1997; Barley 1989) och uppfattar i likhet med Julkunen (2003) och Acker (1990; 2006) ålder och kön som sociala kategorier i organisationsstrukturen. Syftet med denna studie är att undersöka hur unga personer utför identitetsförhandlingar i förhållande till arbetet och idén om en karriär i nuläget, samt sammanbinder karriären, framtiden och livet över lag med sin självidentitet i ett karriärperspektiv. Jag har valt unga konsulter som forskningsobjekt, eftersom endast en liten del av den sociologiska arbetslivsforskningen intresserat sig för just unga. Konsultbranschen är ett intressant forskningsobjekt av samma orsak – denna bransch har behandlats i mycket liten skala i finländsk forskning. Det empiriska materialet består av kvalitativa intervjuer med unga, högutbildade män och kvinnor i konsultbranschen. Som analysmetod har jag använt mig av tema-analys inspirerad av diskursanalys. Genom att undersöka individers identitetsförhandlingar i ett karriärperspektiv hoppas jag kunna bidra med nya synpunkter och infallsvinklar samt bättre förståelse för det postindustriella arbetslivet som karakteriseras av kunskapsintensifiering och snabba förändringar i organisationer. Studien visar att idén om en karriär fungerar som ett medel för designandet av det postmoderna självet på samma sätt som till exempel konsumtionen av vissa varumärken. Enligt studien har den flexibla kapitalismen olika inverkan på män och kvinnors idéer om en karriär och betjänar den manliga karriären betydligt bättre än den kvinnliga, åtminstone så länge traditionella könskonstruktioner dominerar. För männen är det naturligt att totalt utesluta faderskapet från karriärkonstruktionen, vilket får dem att kapitulera inför organisationens krav. För kvinnorna är det lika naturligt att justera idén om den framtida karriären enligt möjliga barn i framtiden. Möjligheten att bejaka moderskapets krav verkar beskydda den kvinnliga självidentiteten från att totalt ge efter för organisationens försök att kontrollera subjektiviteten. De unga informanterna konstruerar sitt arbete i mycket annorlunda termer än vad som traditionellt förknippas med arbete; konsultarbetets projektbaserade karaktär konstrueras som äventyrligt, roligt, intressant och omväxlande. Eftersom avsaknad av långsiktighet och rutiner förknippas med den tid i livet då man är ung, underlättades sammanförandet av konsultarbetet med självidentiteten. Samtidigt visar studien hur svårt individen, som fungerar likt en entreprenör i förhållande till sin arbetsgivare, har att skilja mellan arbete och övrigt liv samtidigt som diskursen om balans mellan arbete och fritid dominerar i samhället. Detta ger upphov till en konstruktion av självet som en lycklig och autonom individ som är nöjd över sitt val av start på karriären och tycker om att jobba, medan de långa arbetsdagarna och kraven på ständig effektivitet och prestationer konstrueras som något naturligt. Slutligen efterlyser studien en omdefiniering av begreppet kunskapsarbete. Arbetssociologin i sin helhet har utgått från tanken om arbete som något ofrivilligt eller som tvång, medan informanterna i denna undersökning tvärtom konstruerar sitt arbete i termer som traditionellt förknippas med fritid och frivillighet . Man kan fråga sig ifall kunskapsarbetet håller på att slita sig loss från den traditionella uppfattningen om arbete och skapa en allt skarpare kontrast till det arbete som utförs i traditionell bemärkelse?