Systematic Investigation of Hydrogel Material Properties on Cell Responses for Vocal Fold and Vascular Graft Tissue Engineering

The research presented here deals with synthetic materials for application in tissue engineering, primarily poly(ethylene glycol) (PEG) and poly(dimethyl siloxane)star (PDMS)star. Tissue engineering seeks to repair or replace damaged tissue through implantation of cell encapsulated in an artificial scaffold. Cell differentiation and extracellular matrix (ECM) deposition can be influenced through a wide variety of in vitro culture techniques including biochemical stimuli, cell-cell interactions, mechanical conditioning and scaffold physical properties. In order to systematically optimize in vitro conditions for tissue engineering experiments, the individual effects of these different components must be studied. PEG hydrogels are a suitable scaffold for this because of their biocompatibility and biological "blank slate" nature. This dissertation presents data investigating: the effects of glycosaminoglycans (GAGs) as biochemical stimuli on pig vocal fold fibroblasts (PVFfs); the effects of mechanical conditioning and cell-cell interactions on smooth muscle cells (SMCs); and the effects of scaffold physical properties on SMCs. Results show that GAGs influence PVFf behavior and are an important component in scaffold design. Hyaluronic acid (HA) formulations showed similar production in collagen I and III as well as reduced levels of smooth muscle a-actin (SMa-actin), while chondroitin sulfate (CSC) and heparin sulfate showed enriched collagen III environments with enhanced expression of SMa-actin. A physiological flow system was developed to give comprehensive control over in vitro mechanical conditioning on TEVGs. Experiments performed on SMCs involved creating multi-layered TEVGs to mimic natural vascular tissue. Constructs subjected to mechanical conditioning with an endothelial cell (EC) layer showed enhanced expression of SMC differentiation markers calponin h1 and myocardin and enhanced deposition of elastin. Consistent with other studies, EC presence diminished overall collagen production and collagen I, specifically. Novel PDMSstar-PEG hydrogels were studied to investigate the effects of inorganic content on mesenchymal stem cell differentiation for use in TEVGs. Results agree with previous observations showing that a ratio of 5:95 PDMSstar: PEG by weight enhances SMC differentiation markers; however, statistically significant conclusions could not be made. By studying and optimizing in vitro culture conditions including scaffold properties, mechanical conditioning and multi-layered cell-cell interactions, TEVGs can be designed to maximize SMC differentiation and ECM production

Scatter of Journals and Literature Obsolescence Reflected in Document Delivery Requests

In this paper we investigate the scattering of journals and literature obsolescence reflected in more than 137,000 document delivery requests submitted to a national document delivery service. W e first summarize the major findings of the study with regards to the performance of the service.We then identify the “core” journals from which article requests were satisfied and address the following research questions: (a) Does the distribution of core) journals conform to the Bradford’s Law of Scattering? (b) Is there a relationship between usage of journals and impact factors, journals with high impact factors being used more often than the rest? (c) Is there a relationship between usage of journals and total citation counts, journals with high total citation counts being used more often than the rest?(d) What is the median age of use (half-life) of requested articles in general? (e) Do requested articles that appear in core journals get obsolete more slowly? (f) Is there a relationship between obsolescence and journal impact factors, journals with high impact factors being obsolete more slowly? (g) Is there a relationship between obsolescence and total citation counts, journals with high total citation counts being obsolete more slowly? Based on the analysis of findings, we found that the distribution of highly and moderately used journal titles conform to Bradford’s Law.The median age of use was 8 years for all requested articles. Ninety percent of the articles requested were 21 years of age or younger.Articles that appeared in 168 core journal titles seem to get obsolete slightly more slowly than those of all titles.W e observed no statistically significant correlations between the frequency of journal use and ISI journal impact factors, and between the frequency of journal use and ISI-Institute for Scientific Information, Philadelphia, PA) cited half-lives for the most heavily used 168 core journal titles.There was a weak correlation between usage of journals and ISI-reported total citation counts.No statistically significant relationship was found between median age of use and journal impact factors and between median age of use and total citation counts.There was a weak negative correlation between ISI journal impact factors and cited half-lives of 168 core journals, and a weak correlation between ISI citation halflives and use half-lives of core journals.No correlation was found between cited half-lives of 168 core journals and their corresponding total citation counts as reported by ISI.Findings of the current study are discussed along with those of other studies

Book Use as a Bradford-Zipf Phenomenon

published or submitted for publicatio

An ethnography of student behavior in secluded and open spaces: Preliminary findings and implications for library space planning

From: Bulick, N. & Frey, S. (2019). An ethnography of student behavior in secluded and open spaces: Preliminary findings and implications for library space planning. In A. Katsirikou (Ed.), Book of abstracts: 11th Qualitative and quantitation methods in libraries QQML 2019 international conference (pp. 189-190). Maryville, Florence, Italy: International Society for the Advancement of Science and Technology. file:///C:/Users/sfrey/Desktop/Book-of-Abstracts_Final_AfterConf_v1.pdf The design of physical space in academic libraries has become an increasingly important focus of concern in serving the diverse needs of contemporary student populations. Responding to trends that shift the focus of library space away from collections-centered to more user-centered design, many are exploring ways of creating a better library user experience. To achieve this aim, valuable research has been conducted by directly asking students to articulate their wants and needs via surveys, and in some cases, interviews. However, little research has been devoted to the systematic field observation of how students’ use library spaces. Even less of this research has synthesized data findings with robust theoretical frameworks. This poster details the preliminary findings of an ethnographic study at a four-year, public university. Researchers designed a protocol to observe students in freely available secluded and non-secluded library spaces to examine behavior, communication, and social interaction within the context of proxemics theory. The anthropological study of proxemics is useful in evaluating how people behave within immediate organizations of space, and has been successfully applied to the design of public and semi-public spaces. Attendees will learn of study findings, and how these data can be applied to practical applications such as furniture composition and layout, lighting, and general space planning. Also addressed are details of the next phase of this study. Keywords: Space/Buildings; Organizational Change; Proxemics2019 International Qualitative and Quantitative Methods in Libraries (QQML) ConferenceSusan M Frey2019 International Qualitative and Quantitative Methods in Libraries (QQML) Conferenc