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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

The Functional Role of Hepatic Argonaute (Ago)-2 Slicer Activity in Metformin’s Action and Glucose Metabolism in Obese Mice

Salem, Esam 22 October 2020 (has links)
No description available.
22

Hur uppstår nya sociala rörelser? : En kvalitativ fallstudie av den nya formen av spontan organisering genom informella nätverk som blev tongivande under flyktingmottagandet 2015 / How are new social movements created? : A qualitative case study of the new form of spontaneous organization through informal networks that became influential during the receiving of refugees in 2015

Holmblad, Carolin January 2017 (has links)
Uppsatsen undersöker den spontana organisering genom informella nätverk som blev ett betydande inslag i Sveriges flyktingmottagande 2015. Utifrån en fallstudie av volontärer som är aktiva i organisationerna undersöker studien vilka motiv som ligger till grund för deras val att engagera sig utanför redan befintliga organisationer. Det huvudsakliga syftet med undersökningen är att studera huruvida den spontana formen av organisering bör betraktas som en ny social rörelse. Uppsatsens teoretiska ramverk utgår från teorier om hur sociala rörelser uppstår samt vad som utmärker mindre formell form av organisering. Sammanlagt genomfördes sju stycken semistrukturerade intervjuer med volontärer från organisationer registrerade i Sverige och som startade under flyktingmottagandet 2015. Bland organisationerna finns de med fokus på mottagandet i Sverige samt de med primärt internationellt fokus. Resultatet visar att volontärernas engagemang i den nya formen av organisering till stor del kan betraktas som en ny social rörelse med hänvisning till uppsatsens teoretiska ramverk.
23

The Passionate Combining Entrepreneurs

Nordström, Carin January 2015 (has links)
Entrepreneurs are portrayed as salient drivers of regional development and for a number of years nascent entrepreneurs have been studied in a large number of countries as part of the Global Entrepreneurship Monitor project and the Panel Study of Entrepreneurial Dynamics. Scholars have devoted much effort to investigating factors that determine how individuals engage in entrepreneurial activities, with most of the discussion limited to business start-ups. However, since this type of project does not follow identical nascent entrepreneurs over time, limited knowledge exists about their development and whether they stay in this nascent phase for a long time. In practice, it is common for entrepreneurs to run a business and at the same time work in wage work, so-called combining entrepreneurs. In Sweden, almost half of all business owners combine wage work with a business. However, not all combining entrepreneurs will eventually decide to leave the wage work and invest fully in the business. Consequently, much research has focused on the first step of entering entrepreneurship full time, but less has focused on the second step, the transition from the combining phase to full-time self-employment. The aim of this thesis is therefore to contribute to the theory of entrepreneurship by gaining a deeper understanding of combining entrepreneurs and their motives and intentions.   In the context of combining entrepreneurs, the theory of identity, resources and choice overload has been used to examine how entrepreneurs’ age (when starting the business), entrepreneurial tenure (the length of engagement in the side-business), hours spent (weekly involvement in the side-business), involvement in entrepreneurial teams (leading the business with one or more partners) and involvement in networks (business networks) influence their passion for engaging in entrepreneurship while sustaining wage work. Different categories of combining entrepreneurs and their intentions have also been examined.   A survey was administered to 1457 entrepreneurs within the creative sector in two counties in Sweden (Gävleborgs County and Jämtlands County). Since there were no separate mailing lists to only combining entrepreneurs, the survey was sent to all entrepreneurs within the chosen industry and counties. The total response rate was 33.5 percent and of them 57.6 percent combined, yielding 262 combining entrepreneurs who answered the questionnaire. The survey was then followed up with eight focus group interviews and two single interviews to validate the answers from the questionnaire.   The results indicate three types of combining entrepreneurs: nascent – with the intention to leave the combining phase for a transition into full-time self-employment, lifestyle – with the intention to stay in the combining phase, and occasional – with the intention to leave the combining phase for full-time wage work and close down the business. Transitioning fully to self-employment increases with the individual’s age. Also, a positive interactive effect exists with involvement in entrepreneurial networks. The results also indicate that the ability to work with something one is passionate about is the top motive for combining wage work with a side-business. Passion is also more likely to be the main motive behind the combining form among individuals who are older at business start-up, but passion is less likely to be the main motive behind the combining form among individuals who spend more time on the business. The longer the individual has had the side-business, the less likely passion is the main motive behind the combining form, and passion is less likely to be the main motive among those who are part of an entrepreneurial team. / <p>Avhandlingen baseras på fem delarbeten, tre var opublicerade vid tidpunkten för disputationen, två länkas här.</p>
24

The Passionate Combining Entrepreneurs

Nordström, Carin January 2015 (has links)
Entrepreneurs are portrayed as salient drivers of regional development and for a number of years nascent entrepreneurs have been studied in a large number of countries as part of the Global Entrepreneurship Monitor project and the Panel Study of Entrepreneurial Dynamics. Scholars have devoted much effort to investigating factors that determine how individuals engage in entrepreneurial activities, with most of the discussion limited to business start-ups. However, since this type of project does not follow identical nascent entrepreneurs over time, limited knowledge exists about their development and whether they stay in this nascent phase for a long time. In practice, it is common for entrepreneurs to run a business and at the same time work in wage work, so-called combining entrepreneurs. In Sweden, almost half of all business owners combine wage work with a business. However, not all combining entrepreneurs will eventually decide to leave the wage work and invest fully in the business. Consequently, much research has focused on the first step of entering entrepreneurship full time, but less has focused on the second step, the transition from the combining phase to full-time self-employment. The aim of this thesis is therefore to contribute to the theory of entrepreneurship by gaining a deeper understanding of combining entrepreneurs and their motives and intentions.   In the context of combining entrepreneurs, the theory of identity, resources and choice overload has been used to examine how entrepreneurs’ age (when starting the business), entrepreneurial tenure (the length of engagement in the side-business), hours spent (weekly involvement in the side-business), involvement in entrepreneurial teams (leading the business with one or more partners) and involvement in networks (business networks) influence their passion for engaging in entrepreneurship while sustaining wage work. Different categories of combining entrepreneurs and their intentions have also been examined.   A survey was administered to 1457 entrepreneurs within the creative sector in two counties in Sweden (Gävleborgs County and Jämtlands County). Since there were no separate mailing lists to only combining entrepreneurs, the survey was sent to all entrepreneurs within the chosen industry and counties. The total response rate was 33.5 percent and of them 57.6 percent combined, yielding 262 combining entrepreneurs who answered the questionnaire. The survey was then followed up with eight focus group interviews and two single interviews to validate the answers from the questionnaire.   The results indicate three types of combining entrepreneurs: nascent – with the intention to leave the combining phase for a transition into full-time self-employment, lifestyle – with the intention to stay in the combining phase, and occasional – with the intention to leave the combining phase for full-time wage work and close down the business. Transitioning fully to self-employment increases with the individual’s age. Also, a positive interactive effect exists with involvement in entrepreneurial networks. The results also indicate that the ability to work with something one is passionate about is the top motive for combining wage work with a side-business. Passion is also more likely to be the main motive behind the combining form among individuals who are older at business start-up, but passion is less likely to be the main motive behind the combining form among individuals who spend more time on the business. The longer the individual has had the side-business, the less likely passion is the main motive behind the combining form, and passion is less likely to be the main motive among those who are part of an entrepreneurial team.
25

Genome-wide identification and characterization of C. elegans DNA replication origins during development / Identification et caractérisation sur tout le génome des origines de réplication de l'ADN chez C. elegans au cours du développement

Rodriguez Martinez, Marta 16 December 2013 (has links)
La réplication de l'ADN chez les eucaryotes commence lorsque le complexe de reconnaissance de l'origine (ORC) se lie à l'ADN puis recrute les facteurs nécessaires à la duplication du génome. Bien que les mécanismes biochimiques et les facteurs impliqués dans l'initiation de la réplication semblent être conservés, les séquences d'ADN (les origines de réplication) sur lesquelles ces événements ont lieu ne le sont pas. L'ensemble des données connues suggèrent fortement un rôle prépondérant de la mise en place des origines de réplication dans la structuration du génome et l'organisation des autres processus cellulaires lors de la différenciation. Comprendre la coordination de ces processus in vivo et au cours du développement est primordial pour déchiffrer la régulation cellulaire dans son contexte réel. Le modèle du développement embryonnaire du nématode C.elegans constitue un outil génétique de premier choix pour l'étude de la mise en place des origines de réplication au cours du développement. Au cours de ma thèse, j'ai dû premièrement développer une technique de culture de C.elegans synchronisée en grosse échelle, afin d'obtenir le matériel nécessaire pour identifier les origines de réplication. Cette technique nous a aussi permis de caractériser, pour la première fois, la croissance synchronisée en bioréacteur d'un métazoaire. D'autre part, l'étude des origines de réplication a révélé une distribution hétérogène des origines de réplication dans les chromosomes qui corrèle avec des domaines de certaines marques épigénétiques, une corrélation avec des séquences d'ADN capables de former des structures cruciformes de l'ADN, ainsi comme une confirmation de la corrélation avec la transcription. Nous avons aussi vu que la corrélation de origines de réplication avec des CpG, est fortement établie après le début de la gastrulation, et que l'association avec des éléments fonctionnels spécifiques du génome, comme les operons, est perdu une fois la transcription embryonnaire deviens nécessaire après la gastrulation. L'ensemble de résultats suggèrent fortement un changement dans l'organisation des origines de réplication après gastrulation, qui corrèle avec des éléments fonctionnels du génome. / Eukaryotic DNA replication begins when the origin recognition complexes (ORC) binds to DNA and recruits the necessary factors for genome duplication. Even though, biochemical mechanisms as well as the factors involved seem to be well conserved, the DNA sequences (replication origins) where these events take place are not. The known data strongly suggest that replication origins establishment may play an important role in genome structuring as well as in the organization of other cellular processes during cell differentiation. To understand how these processes are coordinated in vivo and during development, is essential for deciphering cellular regulation in its real context. C.elegans embryonic development is a genetic tool of first choice for studying replication origins in vivo and their correlation with other genome features and processes during development.During my thesis and with the aim of obtaining enough material for the replication origins identification method, I've had to develop a new technique of synchronized high-scale liquid culture of the nematode C.elegans. This technique has allowed the characterization for the first time of the synchronize growth of a metazoan in bioreactor. Furthermore, the study of replication origins has revealed a heterogenic distribution of replication origins along chromosomes that correlates with specific epigenetic marks. Moreover, replication origins are strongly associated with specific DNA structures able to form cruciforms, and we have confirmed the correlation of replication origins and transcription. This study also show that the association of replication origins with CpGs is greatly increased after gastrulation, and that the association with some genetic elements, such as operons, is reduced after gastrulation begins. Taken together these results show a change of replication origins before and after cell differentiation during embryonic development that correlate with functional genome elements.
26

Ambiguity and intermediation in the early moments of market formation : the case of the UK social investment market

Casasnovas, Guillermo January 2016 (has links)
Markets are arenas of social interaction for the exchange of products and services that are embedded in specific networks, cultures, and political relations. The study of how new markets come into being is a lively area of scholarly debate, and the purpose of this thesis is to shed light on the dynamics of these early moments of market formation. These nascent markets are characterized by the lack of shared meanings and settled rules around their participants, processes, and infrastructure. I approach them with arguments from economic sociology and from theories of organizations and institutions. The empirical context is a longitudinal study of the UK social investment market from 2000 to 2015, a field that intersects the social, financial, and public sectors. Social investment refers to the combination of financial returns and social impact, but the contest over its meaning and practice is itself a part of this analysis. The core data collection is based on interviews, reports, field events, and online sources, which provide an empirical basis to understand the social, cultural, and political processes that are shaping this market. I build on different traditions in the sociology of markets to explore changes over time in the rules, identities, practices, and dominant actors during the early moments of the UK social investment market. My first main finding is that the initial period of uncontested ambiguity is followed by efforts from mainstream organizations to reduce that ambiguity by reshaping rules and practices. This then results in a period of collaborative contestation, where peripheral actors challenge the core features of the field and hinder the path to stability. The second finding is about the role played by intermediary organizations in nascent markets, which consists of building the market infrastructure by connecting actors, developing a language, and establishing rules and practices. These findings point to the importance of theorizing about ambiguity in the early moments of markets. I contribute to this endeavor by specifying some of its features and dynamics, and by emphasizing the centrality of intermediation. I also further our understanding of those markets that span across the worlds of business, policy, and civil society.
27

Dynamic Modelling of a Fixed Bed Reactor to Study the First Instants of Gas Phase Ethylene Polymerisation / Modélisation en dynamique d'un réacteur à lit fixe pour étudier les premiers instants de la polymérisation de l'éthylène en phase gaz

Hazard Browning, Barbara 09 July 2013 (has links)
La polymérisation des oléfines à l'aide de catalyseurs metallocène est une réaction développée au niveau industriel. Bien que les premiers instants de la réaction aient une importance déterminante pour le procédé, ils n'ont fait l'objet que de très peu de travaux de recherche. Dernièrement, le l'équipe du prof. Mc Kenna a conçu un réacteur de type lit fixe pour étudier en détail ces premiers instants de la réaction. Néanmoins, face à la complexité de la réaction étudiée, un travail de modélisation s'avérait nécessaire afin de mieux appréhender l'ensemble des phénomènes influant sur les résultats et ainsi proposer des améliorations à ce montage expérimental. C'est ce travail qui est présenté dans ce manuscrit. Le premier modèle considère le réacteur comme un calorimètre semi-ouvert sur la matière en entrée, et utilise des lois cinétiques simplifiées. Il a ainsi était démontré que l'augmentation de la température dans le réacteur était un paramètre particulièrement important. Le design a ainsi été modifié en conséquence afin de contrôler l'exothermie de la réaction. Dans un second temps, une étude fine sur les mesures de pression récupérées dans le réacteur a été réalisée mettant en avant que le régime transitoire de montée en pression avait un rôle clef sur cette réaction. L'intégration de ces données a permis d'améliorer le modèle utilisé. Contrairement aux résultats obtenus sur des temps de réaction longs, il a été démontré que la désactivation était plus rapide à basse température lors des premiers instants de la réaction / The behaviour of silica supported metallocene catalyst in the early moments of olefin polymerization is not well understood. The complexity, rapidity and high exothermicity of the reaction impede observation of the kinetics and morphological changes. The fixed bed reactor constructed by McKenna’s group is designed to study these first instants of gas phase olefin polymerisation. The purpose of the modelling work presented is to gain understanding and improve the set-up through better knowledge of the reactor conditions. After a literature survey, the existing set-up was reviewed and analysed. A reactor model was constructed and programmed with polymerisation kinetics represented by a simple relation. The model was validated for individual experiments under optimised conditions. Use of the reactor as a calorimeter was evaluated and a state observer for the polymerisation rate was tested. The model was also used to show that very high temperatures are possible in the reactor bed and to simulate effects of changes to reactor construction and operating conditions. The reactor pressurisation profile is non negligible for experiments of shorter duration. New kinetics based on this were incorporated into the model: these were able to represent series of experiments and take account of the deactivation reaction. Contrary to results from longer duration experiments, our model finds initial deactivation does not appear to be controlled by temperature
28

The Relationship Between Corporate Taxation And R&amp;D Investments : A quantitative study of R&amp;D expenditure in U.S. firms when subjected to reductions in corporate taxation

Brattlöf, Linus, Mbenga, Ida January 2021 (has links)
Corporate taxation is a very politicized topic, and policymakers have different perspectives on what level of corporate tax rate yields the optimal outcome for research and innovation activity. The argument is divided where one side believes that corporate taxation and R&amp;D activity has a negative relationship, which implies that a decrease in corporate taxation yields a better outcome for firms’ R&amp;D activity. Whilst the other side believes that there exists a positive relationship, implying that the prevailing strategy is to increase corporate taxes to further encourage R&amp;D activity. Therefore, the inherent purpose of this study focuses on the effect that corporate taxation has on the U.S corporate environment, whilst researching to understand the two polarized perspectives on corporate taxation and discover which perspective appears more prominent. To succeed in this regard, this study extracts internal financial information from firms located in the U.S states, by comparing the corporate tax change that the Trump administration implemented in 2018. Enabling this research study to compare firms’ R&amp;D expenditure during the pre-tax reform (2017) with the post-tax reform (2018), indicating a firm’s differences in R&amp;D expenditure. The difference-in-difference method was used with a total sample size of 71 firms, which uses a control group and a treatment group to negate macro-environmental disruptions to indicate the accurate effects of the tax policy change. The results state that companies that experienced a reduction in corporate taxes raised their R&amp;D expenditure, approximately by 11.60%. This showed that there was a very large increase in R&amp;D activity when corporate taxation was significantly lowered, which would support the literature’s findings that suggested the existence of a negative relationship. However, the research yielded a result that would indicate that the 11.60% increase was not a statistically significant result and that further studies need to be conducted.
29

Parental Support on the Nascent Entrepreneur : An Empirical Study on the Emotional Support Provided by Entrepreneurial Parents

De Laender, Jordan-Dawn, Focke, Antonia January 2021 (has links)
Background: Receiving social support facilitates the founding of a nascent entrepreneurs’ business. Support that is received from entrepreneurial parents contributes towards the development of the entrepreneur’s capabilities as well as potentials, thus, shaping the nascent entrepreneur. Our study will focus on one part of social support, namely emotional support, provided by entrepreneurial parents. While parents intend to positively influence the nascent entrepreneur’s well-being and emotional stability, the exchange of support happens rather simultaneously and unconsciously. Purpose: This thesis aims to create a better understanding of the influence of entrepreneurial parents concerning the support system received by a nascent entrepreneur when in the founding stage. Therefore, creating theoretical consistency in the form of a developed conceptual model, which can be put into the broader context of family business and entrepreneurship. Method: Ontology – Relativism; Epistemology – Social Constructionism; Research Approach – Inductive; Methodology – Exploratory Study; Data Collection – 15 Semi-structured interviews with nascent entrepreneurs and three interviews with entrepreneurial parents; Sampling – Purposive, Convenience and Snowball Sampling; Data Analysis – Grounded Analysis. Conclusion: The influence of entrepreneurial parents affects the support approach of a nascent entrepreneur. Specifically, it contributes to the development of the entrepreneur’s entrepreneurial competence and spirit, which in its turn enhances the entrepreneurial activities connected to the founding of a new business.
30

2A-induced ribosome stalling

Odon, Valèrie M. N. January 2014 (has links)
Originally 2A was characterised in foot-and-mouth disease virus. Site directed mutagenesis identified a C-terminus consensus motif [D(V/I)ExNPGP] and it is proposed that 2A interacts with the exit tunnel of the ribosome in a way that a specific peptide bond is skipped between the last glycine of 2A and the proline of 2B, thus providing a discontinuity in translation, resulting in release of discrete proteins from one single ORF. 2A was also identified in other picornaviruses, positive, single and double-stranded RNA insect viruses and mammalian rotaviruses. A motif present at the C-terminus of the 2A oligopeptide [D(V/I)ExNPGP] is very highly, though not completely conserved . The sequence upstream of this motif shows, however, no apparent conservation between 2As of different viruses. In this study, extensive site-directed mutagenesis were performed on several 2A sequences and a series of ‘hybrid' 2As comprising different consensus motifs juxtaposed with different upstream contexts were created as part of a detailed analysis of the mechanism of 2A-mediated ribosome stalling. The results demonstrated that a minimal region of twenty to twenty-three amino acids interacts with the exit tunnel of the ribosome to bring about a pause in processivity, alter the peptidyl transferase centre geometry and restrict the ribosome A site via two distinctive stalling mechanisms. Other molecular analyses tested here will require further optimisations or alternative methods: a visual method to explore the dynamics of re-initiation of translation from proline codon, purification of the translation-regulating factors and structural resolution of 2A sequences. Previously, cellular 2As were identified in non-LTR retrotransposons of trypanosomes. It is reported here as part of two other cellular organisms Saccoglossus kowalevskii (acorn worm) and Branchiostoma floridae (amphioxus). In the acorn worm, the nucleotides sequences corresponding to 2A motifs were part of the untranslated genome. In amphioxus, three 2A elements were identified in hypothetical proteins, and at the N-terminus of twenty non-LTR retrotransposons.

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