16,078 research outputs found

    Micropatterned carbon nanotube embedded cell-laden gelatin methacrylate hybrid hydrogels for cardiac tissue

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    Thesis (M.A.)--Boston UniversityCardiovascular disease is the leading cause of mortality in the world. Cardiac tissue engineering promises to replace damaged organs and tissues with biologically compatible engineered substitutes. Micro- and nanotechnologies have proven to be effective to address current challenges in tissue engineering and regenerative medicine. A principle approach in tissue engineering is the integration of innovative biomaterials with micro- and nanofabrication techniques to generate constructs that recapitulate the in vivo cellular microenvironments. In this study, highly organized three-dimensional (3D) cardiac tissue constructs in carbon nanotube (CNT) embedded gelatin methacrylate (GelMA) were generated using micropatterning techniques. Neonatal rat ventricular cardiomyocytes (NRVMs) and cardiac fibroblasts (CFs) were used as the primary cardiac cell types to be encapsulated in the three-dimensional tissue constructs. The resulting cardiac constructs in CNT-GelMA hybrid hydrogels from various methods showed enhanced cell viability and higher spontaneous synchronous beating rates, compared to those in pristine GelMA hydrogels. Further studies are necessary to determine the efficacy of micropatterned 3D cardiac tissue constructs in CNT-GelMA hybrid hydrogels for in vitro studies and therapeutic purposes

    A Homage to Beethoven Piano Concerto No.5 Emperor

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    The purpose of this thesis is to explore my personal experience with the reciprocal relationships of the various fields of art. The media of art includes the fine arts, crafts, visual arts, theater, film, music, dance and literature - all genres commonly considered the arts. These different fields are not isolated in and of themselves but rather have mutual connections amongst them. This thesis elucidates my concept of art as one. A vague fondness for the arts drew me to the Seoul Arts High School in 1987. I had a broad interest in art in general, and did not limit myself to any one field even though I majored in sculpture. During three years of my high school days, I experimented with Western Painting, Traditional Eastern Asian Painting, basic sculpture and design and in other arts related courses that combined music and dance with the visual arts. Loyalty to the fundamentals is what I have considered ideal in art since my high school days. Though fundamental cannot be described in a single word, it can be said that the basic underlying theme of art itself is humanity - humanity in reference to everything being created by mankind in any field of art. The meaning art comes from the Latin ars. The Latin word simply defines itself as aesthetic beauty; however, we have expanded that definition to include the fine arts, music, film, dance and literature - all genres commonly considered The Arts. The arts communicate and interconnect amongst their various fields. For example: a composer may create music for a work of poetry; a choreographer may express himself or herself by using specific music; a literary work may serve as the basis for a theatrical work. These seemingly different fields of arts do not possess clearly defined boundaries but rather interact with each other to communicate reciprocally. Thus, I have considered combining different fields of arts, which include fine arts and other fields of art, to seek the fundamentals of art from the aesthetic point of view. My intent for this thesis explanation was to create a body of large-scale, hand built sculpture inspired by Beethoven Piano Concerto No. 5 Emperor. I used the repetitive and sequential use of forms that provide an auditory sense of feeling by visual unity

    FROM ESL LEARNERS TO EFL LEARNERS: A CASE STUDY OF ADOLESCENT KOREAN RETURNEES

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    There are growing populations of Korean parents who wish their children to have a study abroad experience in the ESL (English as a second language) context due to their beliefs that early exposure to an English-speaking environment is beneficial for childrenā€™s English proficiency. However, many children return to South Korea before reaching college age for various reasons, and Korean returnees are concerned on how to maintain (or improve) their childrenā€™s English proficiency in the EFL (English as a foreign language) context. Although there are some studies related to Korean English language learnersā€™ study abroad experiences and second language acquisition, few studies have been conducted to investigate how study abroad experience influences Korean returneesā€™ English language learning experience. The purpose of this qualitative case study was to investigate English language learners who recently returned to South Korea after learning English in the U.S. for more than two years. The research questions were as follows: 1) How do Korean returnees perceive the change of learning status from ESL learners to EFL learners, and 2) What characteristics influence the extent to which Korean returnees maintain or lose their English proficiency after having returned to South Korea? The theoretical framework of this dissertation is based on the related literature of second language acquisition (SLA) theories and study abroad (SA) studies. Among second language acquisition studies, second language attrition theories are investigated and specific Korean education backgrounds are introduced. By using a case study method, I provide an extensive and in-depth description of Korean returneesā€™ English language learning experiences. Data were collected through the researcherā€™s field notes and semi-structured interviews with five participants and their mother. By analyzing Korean returneesā€™ perceptions on ESL and EFL learning contexts, this study extends the literature in the field of second language acquisition and contributes knowledge about factors that motivate English language learners to maintain and improve their English proficiency. This study has implications for English language learners within the U.S. and from other countries who struggle to achieve or at least maintain their second language proficiency

    Patient-Clinician Communications: A Design Intervention for Patients' Comprehension of Their Care

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    Master of Design in Integrative DesignUniversity of Michiganhttps://deepblue.lib.umich.edu/bitstream/2027.42/136866/1/JYShin_2017_MDes-Thesis.pd

    High-Throughput Screening of Acyl-CoA Thioesterase I Mutants Using a Fluid Array Platform

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    Screening target microorganisms from a mutated recombinant library plays a crucial role in advancing synthetic biology and metabolic engineering. However, conventional screening tools have several limitations regarding throughput, cost, and labor. Here, we used the fluid array platform to conduct high-throughput screening (HTS) that identified Escherichia coli ???TesA thioesterase mutants producing elevated yields of free fatty acids (FFAs) from a large (106) mutant library. A growth-based screening method using a TetA-RFP fusion sensing mechanism and a reporter-based screening method using high-level FFA producing mutants were employed to identify these mutants via HTS. The platform was able to cover >95% of the mutation library, and it screened target cells from many arrays of the fluid array platform so that a post-analysis could be conducted by gas chromatography. The ???TesA mutation of each isolated mutant showing improved FFA production in E. coli was characterized, and its enhanced FFA production capability was confirmed

    "Long Term Loans and Investment in Japan: An Empirical Analysis Based on the Panel Data of Japanese Firms"

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    The purpose of this paper is to investigate whether that the policy-based allocation of long-term funds played an important role in promoting the high economic growth in post-war Japan. Using the panel data functions of Japanese firms, we estimate Tobinfs Q investment functions in two different sample periods | 1972-84 and 1985-96. In 1972-84, we find that the long-term loan ratio had an additional positive effect on investment. In particular, the result holds true regardless of the size of corporate cash flows or the type of corporate groupings. However, in 1985-96, we cannot find that a higher ratio of long-term loans increased the Japanese firmfs investment. The result indicates that the size of long-term loans had a great influence on the firmfs investment only before the financial liberalization in Japan.

    Erratum: Funding Acknowledgment

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    WordRank: Learning Word Embeddings via Robust Ranking

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    Embedding words in a vector space has gained a lot of attention in recent years. While state-of-the-art methods provide efficient computation of word similarities via a low-dimensional matrix embedding, their motivation is often left unclear. In this paper, we argue that word embedding can be naturally viewed as a ranking problem due to the ranking nature of the evaluation metrics. Then, based on this insight, we propose a novel framework WordRank that efficiently estimates word representations via robust ranking, in which the attention mechanism and robustness to noise are readily achieved via the DCG-like ranking losses. The performance of WordRank is measured in word similarity and word analogy benchmarks, and the results are compared to the state-of-the-art word embedding techniques. Our algorithm is very competitive to the state-of-the- arts on large corpora, while outperforms them by a significant margin when the training set is limited (i.e., sparse and noisy). With 17 million tokens, WordRank performs almost as well as existing methods using 7.2 billion tokens on a popular word similarity benchmark. Our multi-node distributed implementation of WordRank is publicly available for general usage.Comment: Conference on Empirical Methods in Natural Language Processing (EMNLP), November 1-5, 2016, Austin, Texas, US
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