2,245 research outputs found
Using epigenomic studies in monozygotic twins to improve our understanding of cancer
No full textCancer is a set of diseases that exhibit not only genetic mutations but also a profoundly distorted epigenetic landscape. Over the last two decades, great advances have been made in identifying these alterations and their importance in the initiation and progression of cancer. Epigenetic changes can be seen from the very early stages in tumorigenesis and dysregulation of the epigenome has an increasingly acknowledged pathogenic role. Epigenomic twin studies have great potential to contribute to our understanding of complex diseases, such as cancer. This is because the use of monozygotic twins discordant for cancer enables epigenetic variation analysis without the confounding influence of the constitutive genetic background, age or cohort effects. It therefore allows the identification of susceptibility loci that may be sensitive to modification by the environment. These studies into cancer etiology will potentially lead to robust epigenetic markers for the detection and risk assessment of cance
Birthweight, vitamin D receptor genotype and the programming of osteoporosis
No full textStudies of the association between polymorphisms of the gene for the vitamin D receptor (VDR) and adult bone mass have been inconsistent, pointing to the possibility that gene–environment interactions may vary in different populations. We have demonstrated previously an association between weight in infancy (a marker of the intrauterine and early post-natal environment) and each of adult bone mass and VDR genotype. We therefore sought to extend these observations in an elderly UK cohort and to investigate the possibility of an interaction between these genetic and early environmental markers of later osteoporosis risk. One hundred and sixty-five men and 126 women aged 61–73 years for whom birth records were available underwent bone mass measurements at baseline and follow-up 4 years later. Whole-blood samples were obtained, DNA extracted using standard techniques and polymorphisms in the VDR and collagen type I?1 (Col IA1) genes identified. In the cohort as a whole, there were no significant associations between either birthweight or VDR genotype and bone mineral density (BMD) or bone loss rate at either site. However, the relationship between lumbar spine BMD and VDR genotype varied according to birthweight. Among individuals in the lowest third of birthweight, spine BMD was higher (P = 0.01) in individuals of genotype ‘BB’ after adjustment for age, sex and weight at baseline. In contrast, spine BMD was reduced (P = 0.04) in individuals of the same genotype who were in the highest third of the birthweight distribution. A significant (P = 0.02) statistical interaction was also found between VDR genotype and birthweight as determinants of BMD. Similar but slightly weaker associations were seen between lumbar spine bone mineral content (BMC) and VDR genotype in the lowest birthweight tertile. When examining the relationship between Col1A1 genotype and bone mass, lumbar spine BMC was higher in individuals of genotype ‘Ss’ or ‘ss’ in the lowest birthweight tertile (P = 0.02) after adjustment for age, sex and weight at baseline. These results suggest that genetic influences on adult bone size and mineral density may be modified by undernutrition in utero
Scholarly Communication and Publishing Lunch and Learn Talk #11: The ULS Open Access Author Fee Fund
No full textAt the May 2014 talk, you will learn about the ULS Open Access Author Fee Fund--what it is, why we do it, how it works, and how the program is going so far
Narrative threads: ethnographic tourism, Romani tourist tales, and fiber art
No full textThis thesis examines the need for the ethnographer to process their own emotions and experiences as part of the ethnographic experience. Specifically, it argues for the credibility of artistic expression resulting from fieldwork.
Drawing on the author’s experience during the 2012 inaugural "Romani Music, Culture, and Human Rights" study abroad program at the University of Pittsburgh, this thesis offers an analysis of five works of fiber art. Originally perceived by the author as separate from the thesis writing process, they became an integral part of thesis once they were recognized as the non-verbal processing of the my emotional response to events abroad and, therefore, essential components of the research process.
I argue that emotional processing is an integral part of writing an ethnography, for as the ethnographer works through their experiences, their understanding of the events changes, and this in turn impacts the ways in which the ethnographic is perceived and analyzed
Evaluating Research Impact through Open Access to Scholarly Communication
No full textScientific research is a competitive business – in order to secure funding, promotion and tenure researchers must demonstrate their work has impact in their field. To maximise impact researchers undertake high priority research, aim to get results first, and publish in the highest impact journals. The Internet now presents a new opportunity to the scholarly author seeking higher impact: s/he can now make their work instantly accessible on the Web through author self-archiving. This growing body of open access literature (coupled with new publishing models that make journals available for-free to the reader) maximises research impact by maximising the number of people who can read it, and making it available sooner. Open access also provides a new opportunity for bibliometric research. This thesis describes the relatively recent phenomenon of open access to research literature, tools that were built to collect and analyse that literature, and the results of analyses of the effect of open access and its effect on author behaviour. It shows that articles self-archived by authors receive between 50-250% more citations, that rapid pre-printing on the Web has dramatically reduced the peak citation rate from over a year to virtually instant and how citation-impact – now widely used for evaluation – can be expanded to include a new web metric of download impact
A new breed of publisher: towards open global sharing
No full textThis presentation was given at the Publishing in Libraries Conference at the College at Brockport, State University of New York on March 20, 2015 as part of a panel discussion entitled 'The repository as publisher: opportunities and challenges in a dual role', with Benjamin Hockenberry, Jessica Clemons, and Timothy Deliyannides. The presentation gives an overview of the evolution of the publishing program at the University of Pittsburgh beginning with the dissemination of new scholarly content through author self-archiving repositories and leading to the publication of scholarly peer-reviewed journals with partners located around the world. Pitt's journal publishing program is detailed. The presentation highlights the library's unique perspective, values, and commitment to openly sharing scholarly research in all its forms worldwide
Towards new modes of publishing and information-sharing among researchers at Pitt and internationally
No full textThe Office of Scholarly Communication and Publishing (OSCP) at the University of Pittsburgh Library System is engaged in a wide range of activities to support scholarly communication for researchers at Pitt, with special emphasis on promoting open access to research for the global community of scholars. In this talk, an overview of the activities of OSCP will be shown. In particular, the library’s extensive journal publishing program, D-scholarship@Pitt (publishing via institutional repository), the open access author fee fund, and innovations in measuring the scholarly impact of researchers at Pitt will be described. Additionally, the talk will explore the underlying philosophy and policies behind these activities, and explain the strategic goals of Pitt’s University Library System to demonstrate leadership in scholarly communications, publishing, and information sharing
Marker-Based Paternity Test in Polycross Breeding of Timothy
No full textAlthough the polycross is a useful and cost effective mating design, a lack of paternal pedigree information is a major limitation for polycross breeding in forage grasses such as timothy (Phleum pratense L.). This study describes a paternity test for use in timothy breeding using polymorphic data on 27 genomic simple sequence repeat markers. The paternity test is a simple exclusion statistical test with a combination of maternal information. It successfully determined paternity (success rate = 97%) for 112 progeny plants derived from three polycross groups (A, B, and D). Indirectly selected paternal parents in polycrosses were inferior to maternal parents directly selected by polycross progeny tests mainly for forage yield. Chi-squared values (χ2) in goodness-of-fit tests of the frequency distribution of paternal parents compared with the expected probabilities revealed unbalanced selection in Polycrosses B and D (χ2 = 141.4*** and 82.7***, respectively). Significant differences among the maternal and paternal parents in breeding values for competitiveness toward legumes and low-digestibility fiber content indicate that unbalanced paternal selection would result from individual phenotypic selection for these traits. These results demonstrate that implementation of a marker-based paternity test in timothy polycross breeding could significantly improve the selection of superior paternal parents and redress problems of parental imbalance
Effects of biochemical and mechanical stimulation of articular chondrocytes in collagen-GAG scaffolds : extracellular matrix biosynthesis and scaffold stiffness
No full textThesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004.Includes bibliographical references (p. 55-59).As the incidence of osteoarthritis and other degenerative joint conditions continues to grow, rehabilitation via tissue engineering is becomingly increasingly attractive as an alternative to traditional surgical interventions. Chapters 2 and 3 of this thesis are specifically concerned with cartilage tissue engineering, while chapter 4 is relevant to bone and osteochondral tissue engineering. The cartilage tissue engineering sections focus on the effects of two different classes of regulators of chondrocyte behavior: chemical growth factors and mechanical loading. In chapter 2, FGF-2, a chemical regulator, was supplied to chondrocyte-seeded constructs over a 4 week culture period. Afterward, these constructs were subjected to sequential ramp and hold compressive strains on a Dynastat mechanical testing apparatus, and the unconfined elastic moduli were calculated. These data were compared to the values for scaffolds receiving no FGF. The results indicate that FGF-2 induced a significant increase in the modulus of chondrocyte-seeded scaffolds. Numerous reports indicate that certain types of mechanical loading can increase chondrocytes' ECM biosynthesis in particular cell-scaffold systems in vitro. Few if any loading experiments have been done, however, with type II collagen-GAG scaffolds cultured in serum-free medium. Chapter 3 describes a series of experiments in which chondrocyte-seeded scaffolds were subjected to dynamic compression and the effects of this treatment on the proliferation of the chondrocytes, their synthesis of ECM, and the stiffness of the scaffolds were measured. The results of these experiments were inconclusive. Analysis indicated that very few chondrocytes were retained in the scaffolds.(cont.) A post hoc investigation of the scaffolds revealed that they were biologically inactive due to their oversize pores. The low cell density was reflected in unusually low biosynthesis values and no significant differences in stiffness post-loading. The mechanical properties of implantable constructs such as stiffness and compressive strength are likely to significantly affect the clinical outcome. The fourth chapter describes measurements of the elastic modulus and ultimate compressive strength of a bone scaffold material. Five different scaffold formulations were tested, and the mechanical properties correlated with the variations in their composition.by Timothy D. Gordon.S.M
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