• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 69
  • 13
  • 4
  • 4
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • Tagged with
  • 121
  • 51
  • 21
  • 21
  • 18
  • 17
  • 14
  • 14
  • 14
  • 12
  • 11
  • 10
  • 9
  • 7
  • 7
  • 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.
61

Digit ratio (2D:4D) predicts communion in exploratory structural equation modeling of self-narratives

Unknown Date (has links)
Agency and communion are fundamental dimensions underlying psychological processes. Although agency and communion are coherent dimensions, their origins, nature, stability differ across theoretical framework. Common to these frameworks are gender differences in agency and communion. The present study hypothesized that because agency and communion relate to gender, they may also relate to digit ratio. The present study is important because digit ratio may offer clues on the origins and nature of agency and communion, and their gender differences. Agency and Communion factors were extracted from implicit linguistic measures obtained by LIWC analysis of selfnarratives. Exploratory structural equation modeling indicated communion related to digit ratio in men, and gender differences in communion. Although the results supported the distal, biological influences of communion argued by evolutionary accounts, the null finding agency was not related to digit ratio, while not directly interpretable, did not contradict socialization accounts of agency. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
62

Investigating the RNA Binding Domains of MBNL1 and the Alternative Splicing Motifs They Recognize

Purcell, Jamie, Purcell, Jamie January 2012 (has links)
Muscleblind-like 1 (MBNL1) is a ubiquitously expressed RNA binding protein that regulates the alternative splicing of a variety of transcripts. In Myotonic Dystrophy (DM) aberrant cellular localization of MBNL1 results in disease-associated mis-splicing of several MBNL1 target pre-mRNAs. Due to its role in DM pathogenesis, MBNL1 has been a topic of intense study for the last decade, however many open mechanistic questions remain regarding how MBNL1 recognizes RNA substrates to mediate splicing. The RNA recognition motif for MBNL1, 5'-YGCY-3', was defined herein. This motif was used to identify novel MBNL1 binding sites within regulated transcripts and create synthetic MBNL1-regulated splicing reporters. MBNL1 contains four zinc finger (ZF) RNA binding domains arranged into two pairs of two ZFs. A comprehensive, combinatorial mutagenic study of MBNL1 was conducted to determine the role of each ZF in RNA binding and splicing activity. Functional analysis of the mutant proteins in cellular splicing assays and assessment of RNA binding activity demonstrated that the ZF pairs (i.e. ZF1-2 or ZF3-4) do not have equivalent activity. The ZF1-2 pair is responsible for MBNL1's high affinity RNA binding and splicing activity, whereas the ZF3-4 pair has reduced affinity for RNA and impaired ability to regulate splicing of some transcripts. Hierarchical clustering analysis revealed that two distinct classes of MBNL1-regulated splicing events exist within the small set of splicing events examined. For Class II splicing events the binding and splicing activity for the ZF mutants correlated well. However, for Class I events there was no significant correlation between RNA binding and splicing activity. For pre-mRNAs in the latter class it appears that MBNL1 exerts surprisingly robust splicing activity in the absence of strong RNA binding, suggesting that MBNL1 may be recruited to some pre-mRNA substrates through protein-protein interactions. This study provides the first demonstration that functionally distinct classes of MBNL1-mediated splicing events exist in terms of requirements for different ZFs and the importance of RNA binding. This dissertation includes previously published and unpublished co-authored material as well as recently co-authored material that has been submitted for publication.
63

ZBP-89 expression in hepatocellular carcinoma and its interaction with mutant p53. / CUHK electronic theses & dissertations collection

January 2011 (has links)
Zhang, Zhiyi. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves ). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
64

NMR studies of the ADR1 zinc finger transcription factor /

Schaufler, Lawrence E. January 2001 (has links)
Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 202-216).
65

Role of fluid elasticity and viscous instabilities in proppant transport in hydraulic fractures

Malhotra, Sahil 02 October 2013 (has links)
This dissertation presents an experimental investigation of fluid flow, proppant settling and horizontal proppant transport in hydraulic fractures. The work is divided into two major sections: investigation of proppant settling in polymer-free surfactant-based viscoelastic (VES) fluids and development of a new method of proppant injection, referred to as Alternate-Slug fracturing. VES fluid systems have been used to eliminate polymer-based damage and to efficiently transport proppant into the fracture. Current models and correlations neglect the important influence of fracture walls and fluid elasticity on proppant settling. Experimental data is presented to show that elastic effects can increase or decrease the settling velocity of particles, even in the creeping flow regime. Experimental data shows that significant drag reduction occurs at low Weissenberg number, followed by a transition to drag enhancement at higher Weissenberg numbers. A new correlation is presented for the sphere settling velocity in unbounded viscoelastic fluids as a function of the fluid rheology and the proppant properties. The wall factors for sphere settling velocities in viscoelastic fluids confined between solid parallel plates (fracture walls) are calculated from experimental measurements made on these fluids over a range of Weissenberg numbers. Results indicate that elasticity reduces the retardation effect of the confining walls and this reduction is more pronounced at higher ratios of the particle diameter to spacing between the walls. Shear thinning behavior of fluids is also observed to reduce the retardation effect of the confining walls. A new empirical correlation for wall factors for spheres settling in a viscoelastic fluid confined between two parallel walls is presented. An experimental study on proppant placement using a new method of fracturing referred to as Alternate-Slug fracturing is presented. This method involves alternate injection of low viscosity and high viscosity fluids into the fracture, with proppant pumped in the low viscosity fluid. Experiments are conducted in Hele-Shaw cells to study the growth of viscous fingers over a wide range of viscosity ratios. Data is presented to show that the viscous finger velocities and mixing zone velocities increase with viscosity ratio up to viscosity ratios of about 350 and the trend is consistent with Koval’s theory. However, at higher viscosity ratios the mixing zone velocity values plateau signifying no further effect of viscosity contrast on the growth of fingers and mixing zone. The plateau in the velocities at high viscosity ratios is caused by an increase in the thickness of the displacing fluid and a reduction in the thin film of the displaced fluid on the walls of the Hele-Shaw cell. Fluid elasticity is observed to retard the growth of fingers and leads to growth of multiple thin fingers as compared to a single thick dominant finger in less elastic fluids. Observations show the shielding effect is reduced by fluid elasticity. Elastic effects are observed to reduce the thickness of thin film of displaced fluid on the walls of Hele-Shaw cell. The dominant wave number for the growth of instabilities is observed to be higher in more elastic fluids. At the onset of instability, the interface breaks down into a greater number of fingers in more elastic fluids. Experiments are performed in simulated fractures (slot cells) to show the proppant distribution using alternate-slug fracturing. Observations show alternate-slug fracturing ensures deeper placement of proppant through two primary mechanisms: (a) proppant transport in viscous fingers formed by the low viscosity fluid and (b) an increase in drag force in the polymer slug leading to better entrainment and displacement of any proppant banks that may have formed. The method offers advantages of lower polymer costs, lower pumping horsepower, smaller fracture widths, better control of fluid leak-off and less gel damage compared to conventional gel fracs. / text
66

Risk of hearing loss from combined exposure to hand-arm vibrations and noise

Pettersson, Hans January 2013 (has links)
Hearing loss from noise exposure is one of the most common occupational injuries, and exposure to vibrations may increase the risk of noise-induced hearing loss. Earlier cross-sectional and longitudinal studies found an increased risk of noise-induced hearing loss among workers with vibration-induced white fingers (VWF) symptoms compared to workers without such symptoms. It has been suggested that vibrations to the hand stimulate the sympathetic nervous system and cause vasoconstriction in both the exposed hand and the ears and that this contributes to noise-induced hearing loss. The overall aim of this thesis was to examine how hand-arm vibrations (HAV) interact with noise in the development of noise-induced hearing loss. The experimental study in this thesis examined the effects of HAV and noise, both separately and combined, on the temporary threshold shift (TTS) in hearing in 22 healthy male and female subjects. The two longitudinal studies in this thesis were based on a cohort of 189 male workers at a heavy engineering workshop. The first cohort study examined the risk of noise-induced hearing loss from long-term exposure to HAV and noise. The second cohort study examined if workers with VWF had an increased risk of noise-induced hearing loss compared to workers without such symptoms. Finally, the questionnaire study in this thesis examined the occurrence of Raynaud’s phenomenon among 133 men and women with noise-induced hearing loss in relation to exposure to vibrations. In the experimental study, no differences in TTS in hearing were observed after combined exposure to HAV and noise compared to exposure to only noise. In the first cohort study, there was an increased risk of noise-induced hearing loss with increased exposure to HAV in a noisy environment. In the second cohort study, it was found that workers with VWF had an increased risk of noise-induced hearing loss compared to workers without VWF. In the questionnaire study, many men and women with noise-induced hearing loss had used hand-held vibrating machines suggesting that vibrations might contribute to noise-induced hearing loss. A high prevalence of Raynaud’s phenomenon was found among men. This thesis demonstrated that there was a long-term effect on noise-induced hearing loss from combined exposure to noise and HAV, but no short-term effect, and that having Raynaud’s phenomenon may also increase the risk of noise-induced hearing loss. / Många arbetare använder sig av handhållna vibrerande verktyg. Det utsätter dem för höga nivåer av både buller och vibrationer. Människor som utsätts för höga bullernivåer under lång tid kan skada sin hörsel. Risken för hörselnedsättning orsakad av buller kan eventuellt öka om personen samtidigt är utsatt för vibrationer från handhållna vibrerande verktyg. Syftet med avhandlingen var att studera om vibrationer i kombination med buller ökar risken för hörselnedsättning. Avhandlingen består av fyra studier. Den första studien är en experimentell studie med 22 friska deltagare med god hörsel. Denna studie undersökte hur hörseln tillfälligt påverkas av buller och vibrationer, separat och i kombination. Den andra och tredje studien bygger på en population bestående av 189 verkstadsarbetare i Sundsvall som följts regelbundet sedan 1987. Den andra studien undersökte om det finns en ökad risk för hörselnedsättning för arbetare som utsätts för buller och vibrationer under lång tid. Den tredje studien undersökte om arbetare med vita fingrar har en ökad risk för hörselnedsättning än arbetare utan vita fingrar. Vita fingrar är en kärlskada orsakad av vibrationer som gör att fingrarna reagerar onormalt snabbt på kyla. Fingrarna blir vita när blodtillförseln till dem stryps. Den fjärde studien är en enkätstudie med 342 kvinnor och män som har en bekräftad hörselnedsättning orsakad av buller. Studien undersökte hur många ur denna grupp som utsätts för vibrationer samt har vita fingrar. Resultaten från studierna visar att det inte finns någon skillnad i hörselpåverkan från buller och vibrationer i kombination jämfört med enbart buller under kort tid. De som utsätts för vibrationer från handhållna vibrerande verktyg i en bullrig miljö under lång tid har en ökad risk för hörselnedsättning. Arbetare med vita fingrar har en högre risk för hörselnedsättning än de utan. En hög andel av de med hörselnedsättning orsakad av buller använder sig av handhållna vibrerande verktyg. I studien fanns även en hög andel med vita fingrar. Sammanfattningsvis visar resultaten att det finns en långtidseffekt av buller och vibrationer på hörselnedsättning men inte någon korttidseffekt, och att vita fingrar kan påverka risken för hörselnedsättning.
67

Evidence for the involvement of the zinc cluster protein Asg1p in the transcriptional regulation of some stress response genes in Saccharomyces cerevisiae

Drolet, Jessica Ann. January 2007 (has links)
Saccharomyces cerevisiae has developed mechanisms in order to survive harsh environmental conditions. This species responds to stresses such as ethanol, heat, and weak acid exposure via two well-characterized stress response pathways. These typically involve either the Hsf1p or the Msn2/4p transcriptional regulators. Recently, our lab has begun to characterize a member of the zinc cluster protein family: Asg1p (Activator of Stress Genes, systematic name: YIL130W), which is presumed to stimulate stress response genes independently of the Hsflp and Msn2/4p pathways. Previous work has revealed five target genes of Asg1p (HSP30, STP4, YER130C, TPO2, YRO2) thought to be involved in this novel stress response pathway. In this study, we attempted to better characterize the role of Asg1p and its target genes during stress induction. We first determined if the induction of certain Asg1p target genes by stress is strain specific. HSP30 induction by heat shock is specific to the W303 strain as shown by primer extension analysis. We then generated the deletion strains Deltaasg1 and Astp4 in W303. We observed a loss of induction of HSP30 in the Deltaasg1 deletion strain when cells were exposed to ethanol. This led us to believe that Asg1p does play a role in the stress response pathway. Also, we attempted to globally define the target sites of Asg1p in vivo on a genome-wide scale by combining Chromatin Immuno Precipitation with microarrays (ChIP-chip). We identified eight putative Asg1p target genes: YRO2, HSP78, ZRT2, ZRT1, MSN4, STP4, TPO2, and HSP30.
68

The p53-induced gene wig-1 : regulation of expression and role in embryonic development /

Wilhelm, Margareta, January 2003 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 4 uppsatser.
69

ZNF451 is a novel binding partner of the bHLH transcription factor E₁₂

Zhou, Shengli. January 2008 (has links)
Thesis (M.S.)--University of Toledo, 2008. / "In partial fulfillment of the requirements for the degree of Master of Science in Biomedical Sciences." Title from title page of PDF document. Bibliography: pages 49-62.
70

Mediation of pleiotropic drug resistance by zinc cluster transcriptional regulators in Saccharomyces cerevisiae

Patel, Reena, January 2009 (has links)
Thesis (M.Sc.). / Written for the Division of Experimental Medicine. Title from title page of PDF (viewed 2009/06/30). Includes bibliographical references.

Page generated in 0.058 seconds