601 research outputs found
Designing a Whey Protein Based Material as a Scaffold for Bone Regeneration
A novel gel material was designed and optimized for use as a bone tissue regeneration scaffold. Whey protein isolate (WPI), the primary component of the material, underwent considerable testing for conformity to a set of known material characteristics required for application in bone regeneration. WPI gels of different compositions were fabricated by thermally inducing gelation of high-concentration protein suspensions, and characterized for compressive strength and modulus, hydration swelling and drying properties, mechanical behavior change due to polysaccharide additives, and intrinsic pore network structure. The gels were also tested for their compatibility with MC3T3-E1 cells, and interactions such as cell adhesion, cytotoxicity, proliferation kinetics, and bone formation, were characterized for gels of different compositions. Some properties of interest were composition- and processing-dependent, while others varied little with such variables. Results revealed that the most favorable mechanical properties could be obtained by using a material of 40% w/v WPI, 10 mM CaCl2, and 0.2 g amylopectin per g WPI. The mechanical properties of this composite approached the ultimate strength necessary for a load-bearing scaffold, and were within one order of magnitude of the lower limit of the necessary compressive modulus. The proper modulus could likely be achieved by converting the conventional composite to a nanocomposite. The observed cell-scaffold interactions were highly suitable. All tested naïve gels and composites supported the adhesion and proliferation of the model cell line for extended culture periods. Amylopectin incorporation decreased initial preosteoblast adhesion but improved the proliferation rate constant – the more important system parameter. Both the naïve gel and the composites enabled cells to differentiate and create bone in vitro, and sustained viability for the length of the 4-week study. The current fabrication technique left insufficient porosity and interconnectivity for a bone scaffold, though the necessary pore size distribution was achieved. The effect of WPI concentration and precursor suspension viscosity on these properties was thoroughly characterized. In order to correct the disparity in properties, a method for electrospinning WPI was developed, and shows great promise. While further studies are required, the developed composite has significant potential for implementation in the industry
What Does it Mean to Teach Interpretively?
The ‘interpretive turn’ has gained traction as a research approach in recent decades in the empirical social sciences. While the contributions of interpretive research and interpretive research methods are clear, we wonder: Does an interpretive perspective lend itself to – or even demand – a particular style of teaching? This question was at the heart of a roundtable discussion we organised at the 2014 Interpretive Policy Analysis (IPA) International Conference. This essay reports on the contours of the discussion, with a focus on our reflections upon what it might mean to teach ‘interpretively’. Prior to outlining these, we introduce the defining characteristics of an interpretive perspective and describe our respective experiences and interests in this conversation. In the hope that this essay might constitute the beginning of a wider conversation, we close it with an invitation for others to respond
Mapping Genes for Complex Traits: Obesity, Diabetes, Hypertension, and Dyslipidemia on the Pacific Island of Kosrae
One of the current challenges in human genetics is to map genes for common, complex diseases. For powerful mapping of such phenotypes, the suggestions are to analyze the underlying quantitative traits with covariate corrections in large extended pedigrees with multipoint analysis. This is virtually impossible to do with the current linkage programs, due to the computation difficulties of exactly calculating every possibility. Instead, sampling methods that sample the most likely data configuration from all the possibilities need to be used. This has been implemented in the reversible jump Markov chain Monte Carlo method Loki, which can carry out segregation and linkage analysis on quantitative traits in large pedigrees with multipoint analysis. Loki can model the trait with covariates, identify the number of quantitative trait loci, linked loci, and estimate allele frequencies and gene effects. This method has a lot promise but has not been vigorously tested for complete genome scans. The first part of this study was to develop a strategy for carrying out genome scans using Loki and to evaluate the output. This was first done using the Genetic Analysis Workshop 12 simulated dataset with known answers. This resulted in a number of suggestions, such as initial single chromosome analysis, correction for polygenic effect, joint analysis of positive signals, and convergence analysis. Next these suggestions were applied to a real dataset from the population of Kosrae, the Federated States of Micronesia. This is a study of the population on the island of Kosrae, which one large extended pedigree and high prevalence of the common complex disorders that are known as Syndrome X: obesity, type II diabetes, hypertension, and dyslipidemia. This resulted in a number of additional suggestions, such as phenotypic and genotypic corrections, dealing with mixing issues, and inspection of L-graphs for signal reliability. Once this strategy was developed, the second part of this study was to use Loki to identify quantitative trait loci for the continuous traits associated with Syndrome X and stature. This resulted in quantitative trait loci for body mass index, hip circumference, weight, fasting blood sugar, systolic blood pressure, arterial blood pressure, apolipoprotein B, total cholesterol, and height. This also identified interesting chromosomal regions with slight signals for correlated traits on chromosomes 1, 2, 7, 9, 13, and 16. This study shows that Loki is a program that can powerfully and reliably carry out linkage analysis on quantitative traits that was previously impossible to do and finds loci for many of the quantitative traits related to common metabolic disorders as well as height
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Keepers of the vision : students\u27 perceptions of themselves as creators and changers.
This qualitative study undertook an exploration into the connections between creativity and change/transformation. Its purpose was to begin to understand how creativity could be used as a tool for empowerment, liberation, and transformation, and how creative techniques could be incorporated into educational efforts. Participants were students who were enrolled in an undergraduate course designed and taught by the researcher, entitled Creativity and Change. Using their coursework and interviews, this research explored how these student/participants perceived of themselves as creative individuals and as persons capable of making change in their lives and in the world, how they connected the two concepts of creativity and change, and how they utilized creative processes in envisioning change strategies. This study broke ground in two areas of creativity research: (1) looking at the effects and benefits of a creativity class from the perspective of the students who were enrolled in it, and (2) expanding on the research on climate for creativity by connecting creativity to personal and social change efforts, again, from the perspective of students. The results of this study are a beginning to better understanding the multiple aspects of creativity--expression, process, products--and their importance ta self-development, empowerment, and liberation in education. The responses of the students who participated in this study were encouraging in supporting the premise that there are multiple connections between creativity and change. They demonstrated the effects of creativity in increasing self-knowledge and self-esteem, making connections between people, envisioning solutions to social problems, expanding perceptions to incorporate different perspectives and viewpoints, breaking boundaries, and taking the risks that transformation demands. These student/participants demonstrated, through the discovery of their own creative, capable selves, a sense of empowerment arising from the knowledge that I CAN. Being able to think outside of conventional structures and paradigms, challenging dualistic thought, and incorporating holistic teaching and learning strategies are some of the strengths and gifts of creativity. This study has shown that the openness and imagination of creative thought and behavior can become a tool to dismantle the injustices of the world and create new, transformative paradigms
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