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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.
71

THE DEVELOPMENT AND COMMITMENT OF T HELPER SUBSETS

Stritesky, Gretta L. 09 March 2011 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / T helper cells play a crucial role in providing protection against a wide variety of pathogens. The differentiation and effector function of T helper cell subsets is dependent on cytokine activation of Signal Transducer and Activator of Transcription (STAT) family members. The development of Th17 cells, which are important for immunity to fungi and extracellular bacteria, relies on STAT3. We show that IL-23 in combination with IL-1β promotes maintenance of the Th17 phenotype following multiple rounds of stimulation. However, IL-23 does not promote commitment of Th17 cells, and when Th17 cells are cultured with IL-12 or IL-4 they switch to a Th1 and Th2 phenotype, respectively. The maintenance of the Th17 phenotype by IL-23 also requires STAT4. STAT4-deficient memory cells cultured with IL-23 have reduced IL-17 production following stimulation with either anti-CD3 or IL-18+IL-23 stimulation compared to wild type memory cells. Furthermore, STAT4-deficient mice have impaired in vivo Th17 development following immunization with ovalbumin. This challenges a one-STAT/one-subset paradigm and suggests that multiple STAT proteins can contribute to a single phenotype. To test this further we examined whether STAT3 is required for the development of Th2 cells, a subset known to depend upon the IL-4-induced activation of STAT6 for immunity to parasites and promoting allergic inflammation. We demonstrate that in the absence of STAT3, the expression of Th2-associated cytokines and transcription factors is dramatically reduced. STAT3 is also required for in vivo development of Th2 cells. Moreover, allergic inflammation is diminished in mice that have T cells lacking expression of STAT3. STAT3 does not affect STAT6 activation, but does impact how STAT6 functions in binding target genes. Thus, multiple STAT proteins can cooperate in promoting the development of specific T helper subsets.
72

An Examination of the Impact of Studying Abroad with AFS on Level of Differentiation

Issenmann, Anthony John 24 October 2008 (has links)
The purpose of this study was to examine differences in the changes in levels of differentiation, as measured by the Differentiation of Self Inventory (DSI) (Knauth & Skowron, 2004), that occurred among high school students who participated in a semester-long (n = 69) and year-long (n = 119) AFS (formerly known as American Field Service) program and a control group (n = 75) that did not study abroad. Gender of student and level of individualism of host country were also examined. The DSI full scale and four subscales: emotional reactivity, I position, emotional cutoff, and fusion with others were used to assess levels of differentiation. This study was a non-equivalent control group experimental pretest-posttest design. Pretest scores were used as the covariate in the posttest ANCOVA. Results revealed that female students who studied abroad for both one year and one semester experienced significant increases in levels of differentiation as measured by the DSI full scale versus female students who did not study abroad. There were no significant differences among males who studied abroad for one year, one semester or not at all. Additional results indicate a significant difference in changes in level of differentiation, as measured by the DSI full scale, between genders in the control group and the semester abroad group. Additional gender differences were revealed on the emotional reactivity and fusion with others subscales. Level of host country's individualism was not a significant factor. Results support previous literature which states that males and females engage in differing processes when forming their identity. Results also demonstrate that studying abroad is a meaningful life experience significant enough to assist females with increasing levels of differentiation. Additional results, a discussion of the results, limitations, and implications for practice and research are also provided. / Ph. D.
73

Control of self-renewal and pluripotency by the Mbd3/NuRD complex

Signolet, Jason George January 2014 (has links)
No description available.
74

Study of melting and differentiation in iron meteorite parent bodies : How ambient temperature and abundance of 26Al affect accretion times

Mattson, Tuomas January 2016 (has links)
This bachelor thesis consists of two parts. The first part consists of a review of the theoretical background. It starts off with a shorter review on theories of the history of the early Solar System, from protostellar evolution to grain agglomeration. This is then followed by a brief summary of different kinds of meteorites, what their origins might be and the radiometric dating techniques used to determine their ages. The second part of the thesis consists of an investigation of the possible forming times of the early planetesimals by computer simulation. These planetesimals can later become the parent bodies for iron-rich meteorites. Factors studied are ambient temperature and the abundance of the short-lived radioactive isotope 26Al in the forming nebula. The study found that the parent bodies of iron meteorites had to accrete within the first few million years after the earliest solids in the Solar System, the CAI. It also found that changes in the studied boundary conditions did extend this period, but not further than around 2.8Myrs compared to the standard 2.1Myrs. This data compares well to other, similar, studies. / Denna kandidatuppsats består av två delar. Först sammanfattas teorier om hur solsystemet tros ha formats, från hur solens närområde kan ha sett ut till hur de första himlakroppsembryona kan ha börjat formas. Detta följs av en kortare sammanfattning av olika typer av meteoriter och var de kan ha kommit från. Dessutom sammanfattas några tekniker som används för att bestämma åldern på dessa meteoriter. Huvuddelen av uppsatsen består av en undersökning av hur och när de kroppar järnrika meteoriter kommer från kan ha bildats med hjälp av en datorsimulering, och hur olika parametrar såsom temperatur och mängd radioaktiva isotoper kan ha påverkat denna tid. Undersökningen kom fram till att himlakropparna måste ha bildats snart, inom ca 2 Mår, efter de tidigaste kända delarna av vårt solsystem, CAI. Förändringar i de undersökta parametrarna kunde ändra denna tid något, men inte till senare än ca 2.8 Mår efter CAI. Detta stämmer väl med andra, liknande, studier.
75

Characterization of the roles of PAK5 in neuronal celldifferentiation

Poon, Hoi-fung., 潘海鋒. January 2009 (has links)
published_or_final_version / Anatomy / Master / Master of Philosophy
76

Molecular studies on the swarming migration of Proteus mirabilis

Lai, Hsin-Chih January 1994 (has links)
No description available.
77

Studies on the regulation and evolution of tra-1, the terminal somatic sex determining gene in Caenorhabditis elegans

De Bono, Mario Godwin January 1994 (has links)
No description available.
78

Cellular and molecular characterisation of vanadate-induced phenotypic change in PC12 cells

Buensuceso, Charito Saradpon January 1995 (has links)
No description available.
79

Banach function algebras and their properties

Bland, William J. January 2001 (has links)
No description available.
80

A 'dyslexia-friendly' school, but only for the 'right sort' of dyslexic : responding to individual differences in a private school context

Collins, Elizabeth January 2005 (has links)
This research set out to examine the barriers to a secondary private school in implementing dyslexia-friendly practice and responding to different needs, through an in-depth case study of a girls’ school where this was an acknowledged aim. Data were collected through participant observation, interviews with staff, pupils and other key informants. Adolescent girls were chosen as the focus in relation to issues of self-esteem. Before looking at potential barriers, perspectives of pupils in three different private schools for girls were examined in order to investigate how significant practices designated as dyslexia friendly were in the experience of adolescent girls. This suggested that there was no significant difference in the practices and teaching strategies found helpful by dyslexic or non-dyslexic pupils. What was significant was the strength of reaction to teaching strategies that were perceived as patronising or critical, despite often being intended as helpful. Examinations of teachers’ beliefs about the nature of difficulties showed that even where there appeared to be an interventionist perspective, this was diluted in the case of pupils who did not fit the profile of the ‘right sort of dyslexic’ who would reflect well on staff and school. Three significant barriers to the development of more inclusive practice were identified: the culture of autonomy in the classroom and suspicion of collaborative work; a high level of dependence on ability grouping; lack of consensus over the role of the Special Educational Needs Coordinator (SENCO). Significance of the findings in relation to the current dichotomy in the wider educational setting between league table pressures on one hand and inclusive ideology on the other is discussed and suggestions are made about areas for further investigation.

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