111 resultados para Hardy, Alan


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Lactobacillus rhamnosus GG is a probiotic bacterium that is known worldwide. Since its discovery in 1985, the health effects and biology of this health-promoting strain have been researched at an increasing rate. However, knowledge of the molecular biology responsible for these health effects is limited, even though research in this area has continued to grow since the publication of the whole genome sequence of L. rhamnosus GG in 2009. In this thesis, the molecular biology of L. rhamnosus GG was explored by mapping the changes in protein levels in response to diverse stress factors and environmental conditions. The proteomics data were supplemented with transcriptome level mapping of gene expression. The harsh conditions of the gastro-intestinal tract, which involve acidic conditions and detergent-like bile acids, are a notable challenge to the survival of probiotic bacteria. To simulate these conditions, L. rhamnosus GG was exposed to a sudden bile stress, and several stress response mechanisms were revealed, among others various changes in the cell envelope properties. L. rhamnosus GG also responded in various ways to mild acid stress, which probiotic bacteria may face in dairy fermentations and product formulations. The acid stress response of L. rhamnosus GG included changes in central metabolism and specific responses related to the control of intracellular pH. Altogether, L. rhamnosus GG was shown to possess a large repertoire of mechanisms for responding to stress conditions, which is a beneficial character of a probiotic organism. Adaptation to different growth conditions was studied by comparing the proteome level responses of L. rhamnosus GG to divergent growth media and to different phases of growth. Comparing different growth phases revealed that the metabolism of L. rhamnosus GG is modified markedly during shift from the exponential to the stationary phase of growth. These changes were seen both at proteome and transcriptome levels and in various different cellular functions. When the growth of L. rhamnosus GG in a rich laboratory medium and in an industrial whey-based medium was compared, various differences in metabolism and in factors affecting the cell surface properties could be seen. These results led us to recommend that the industrial-type media should be used in laboratory studies of L. rhamnosus GG and other probiotic bacteria to achieve a similar physiological state for the bacteria as that found in industrial products, which would thus yield more relevant information about the bacteria. In addition, an interesting phenomenon of protein phosphorylation was observed in L. rhamnosus GG. Phosphorylation of several proteins of L. rhamnosus GG was detected, and there were hints that the degree of phosphorylation may be dependent on the growth pH.

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This dissertation empirically explored interest as a motivational force in university studies, including the role it currently plays and possible ways of enhancing this role as a student motivator. The general research questions were as follows: 1) What role does interest play in university studies? 2) What explains academic success if studying is not based on interest? 3) How do different learning environments support or impede interest-based studying? Four empirical studies addressed these questions. Study 1 (n=536) compared first-year students explanations of their disciplinary choices in three fields: veterinary medicine, humanities and law. Study 2 (n=28) focused on the role of individual interest in the humanities and veterinary medicine, fields which are very different from each other as regards their nature of studying. Study 3 (n=52) explored veterinary students motivation and study practices in relation to their study success. Study 4 (n=16) explored veterinary students interest experience in individual lectures on a daily basis. By comparing different fields and focusing on one study field in more detail, it was possible to obtain a many-sided picture of the role of interest in different learning environments. Questionnaires and quantitative methods have often been used to measure interest in academic learning. The present work is based mostly on qualitative data, and qualitative methods were applied to add to the previous research. Study 1 explored students open-ended answers, and these provided a basis for the interviews in Study 2. Study 3 explored veterinary students portfolios in a longitudinal setting. For Study 4, a diary including both qualitative and quantitative measures was designed to capture veterinary students interest experience. Qualitative content analysis was applied in all four studies, but quantitative analyses were also added. The thesis showed that university students often explain their disciplinary choices in terms of interest. Because interest is related to high-quality learning, the students seemed to have a good foundation for successful studies. However, the learning environments did not always support interest-based studying; Time-management and coping skills were found to be more important than interest in terms of study success. The results also indicated that interest is not the only motivational variable behind university studies. For example, future goals are needed in order to complete a degree. Even so, the results clearly indicated that it would be worth supporting interest-based studying both in professionally and generally oriented study fields. This support is important not only to promote high-quality learning but also meaningful studying, student well-being, and life-long learning.

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The loss and degradation of forest cover is currently a globally recognised problem. The fragmentation of forests is further affecting the biodiversity and well-being of the ecosystems also in Kenya. This study focuses on two indigenous tropical montane forests in the Taita Hills in southeastern Kenya. The study is a part of the TAITA-project within the Department of Geography in the University of Helsinki. The study forests, Ngangao and Chawia, are studied by remote sensing and GIS methods. The main data includes black and white aerial photography from 1955 and true colour digital camera data from 2004. This data is used to produce aerial mosaics from the study areas. The land cover of these study areas is studied by visual interpretation, pixel-based supervised classification and object-oriented supervised classification. The change of the forest cover is studied with GIS methods using the visual interpretations from 1955 and 2004. Furthermore, the present state of the study forests is assessed with leaf area index and canopy closure parameters retrieved from hemispherical photographs as well as with additional, previously collected forest health monitoring data. The canopy parameters are also compared with textural parameters from digital aerial mosaics. This study concludes that the classification of forest areas by using true colour data is not an easy task although the digital aerial mosaics are proved to be very accurate. The best classifications are still achieved with visual interpretation methods as the accuracies of the pixel-based and object-oriented supervised classification methods are not satisfying. According to the change detection of the land cover in the study areas, the area of indigenous woodland in both forests has decreased in 1955 2004. However in Ngangao, the overall woodland area has grown mainly because of plantations of exotic species. In general, the land cover of both study areas is more fragmented in 2004 than in 1955. Although the forest area has decreased, forests seem to have a more optimistic future than before. This is due to the increasing appreciation of the forest areas.

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The aim of this master s thesis was to clarify employees views on outsourcing. The main questions of the study were 1) How the employees dealt with the change created by outsourcing and what things they felt important when implementing the change? 2) What kind of organizational questions the employees paid attention to when moving from one organization to another? 3) What kind of management issues the employees brought up in the outsourcing process? and 4) How the employees reflected change while experienced outsourcing? The theoretical foundations of the study were Jack Mezirow s theory of transformational learning and Yrjö Engeström s theory of expansive learning. The management of outsourcing was viewed by John P. Kotter s change management model. Research casted light on transformation and learning on four levels of analysis: on individual, organizational and management levels and on the level of reflection. The target of the study were the outsourced employees, who were moved from a Finnish public corporation to a private ITC organization along with the services they produce. The study material was eleven interviews from the outsourced employees. The study was implemented by fenomenographical theme analysis. The analysis revealed results in all four levels. On the individual level the main results were the importance of systematic and open information, meaning of social and technical integration and the feeling of employee s own control. On the organizational level the move from the public sector to private and all the changes in organizational culture and in fringe benefitswere fundamental. Organizational learning was analyzed with expansive learning theory. Expanding was perceived in four dimensions: temporal dimension, spatial dimension, responsibility-moral dimension and developmental dimension. On the management level the actions of one s closest manager was vital, as was the upper management s clear engagement and a shared view of the necessity of a change. In the data was found employees reflective talking, which was indicating the meaning of the change and which was interpreted from the learning point of view. According to this study, it is possible to identify and analyze reflective talk and that way have information about employees learning in an organizational change. It was prominent to notice how reflection in the process of outsourcing is extremely versatile and extensive.

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Taman tutkielman tarkoituksena oli selvittaa metsikon rakenteen seka hakkuiden vaikutuksia pintakasvillisuuden lajikoostumukseen ja biomassaan Etela-Suomen lehtomaisilla, tuoreilla ja kuivahkoilla kankailla. Aineistona tassa tyossa on 8. valtakunnan metsien inventoinnin yhteydessa vuosina 1985–86 metsaluonnon ja ympariston tilan seurantaa varten perustetuista noin 3 000 pysyvasta koealasta poimittu otos. Pintakasvillisuuden lajisto muuttuu metsikon kehitysvaiheen mukaan. Hakkuu on huomattava hairio, joka aiheuttaa nopeita ja suuria muutoksia pintakasvillisuudessa. Pintakasvillisuutta on tarkasteltu lahinna lajiryhmittain (heinat, ruohot, varvut, sammalet seka jakalat). Kunkin lajiryhman peittavyyden eroavaisuuksia testattiin varianssianalyysilla kun selittavana muuttujana ovat luokittain metsikon ika ja edellisesta hakkuusta kulunut aika. Lajikohtaisia tarkasteluja on sen sijaan tehty kasvillisuuden ordinaatioanalyyseilla. Tassa kaytetty ordinaatiomenetelma on epametrinen moniulotteinen skaalaus (Non-metric multidimensional scaling, NMDS), jonka avulla voidaan tehda paatelmia kasvillisuuden rakenteen ekologisesta vaihtelusta ymparistomuuttujien suhteen. Harvennus- ja avohakkuiden vaikutuksia pintakasvillisuuteen myos mallinnettiin lajiryhmittain kayttaen yleistettyja lineaarisia malleja (Generalized linear models). Lajiryhmien peittavyyksien kehitysta mallinnettiin puuston pohjapinta-alan funktiona. Metsikon ian kasvaessa heinien ja ruohojen osuus pienenee, kun taas varpujen ja sammalten osuus lisaantyy. Harvennushakkuiden vaikutukset ovat lievempia kuin avohakkuiden eivatka ne useimmiten aiheuttaneet tilastollisesti merkittavia muutoksia pintakasvillisuuden peittavyyksissa. Avohakkuu sen sijaan on voimakkaampi ja aiheuttaa merkittavia muutoksia. Heinia ja ruohoja esiintyy hakkuun jalkeen enemman ja vastaavasti sammalet ja varvut taantuvat. Kasvillisuuden kokonaispeittavyys ja biomassa ovat suurimmillaan hakkaamattomissa metsikoissa. Harvennushakkuun jalkeen peittavyys ja biomassa voi kuitenkin hetkellisesti olla suurimmillaan kun harvennuksesta on kulunut muutama vuosi. Yleistetyt lineaariset mallit kuvasivat pintakasvillisuuden kehitysta metsikon pohjapinta-alan funktiona luotettavasti. Malleja voidaan kayttaa myos ennustamaan miten pintakasvillisuus kehittyy avohakkuun jalkeen. Malleja voidaan soveltaa esimerkiksi laskettaessa pintakasvillisuuden sitoman hiilen maaraa eriikaisissa metsissa. Niiden avulla voidaan myos arvioida esimerkiksi avohakkuuta voimaperaisemman energiapuun korjuun vaikutuksia pintakasvillisuuden runsauteen.

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I seminariet samlades nordiska experter inom fältet för att diskutera om de aktuella frågorna gällande administrativa sanktioner.