21,341 research outputs found
Advanced Recital: Charlotte Hwang and Rawslyn Ruffin, composition
No full textThis recital is given in partial fulfillment of the requirements for the Master of Music degreeMs. Hwang is a student of Arthur Gottschalk. Ms. Ruffin is a student of Paul Cooper.The Bug-A-Boo Song Cycle (Poems by Ogden Nash), Rawslyn Ruffin (1959) -- Brass Quintet, Charlotte Hwang (b. 1959) -- Variations on a Theme by R. F. T. Schlumberger, Rawslyn Ruffin -- Three Character Sketches, Poems by e. e. cummings, Charlotte Hwang -- Brass Quintet in Five Movements, Rawslyn Ruffin -- Perspicuity, Charlotte Hwang -- Fantasia/Bolero, Rawslyn Ruffi
The Importance of Proofs of Security for Key Establishment Protocols: Formal Analysis of Jan-Chen, Yang-Shen-Shieh, Kim-Huh-Hwang-Lee, Lin-Sun-Hwang, and Yeh-Sun Protocols
No full textDespite the importance of proofs in assuring protocol implementers about the security properties of key establishment protocols, many protocol designers fail to provide any proof of security. Flaws detected long after the publication and/or implementation of protocols will erode the credibility of key establishment protocols. We revisit recent work of Choo, Boyd, Hitchcock, & Maitland (2004) where they utilize the Bellare, Pointcheval, & Rogaway (2000) computational complexity proof model in a machine specification and analysis (using an automated model checker -- SHVT) for provably-secure key establishment protocol analysis. We then examine several key establishment protocols without proofs of security, namely: protocols due to Jan & Chen (2004), Yang, Shen, & Shieh (1999), Kim, Huh, Hwang, & Lee (2004), Lin, Sun, & Hwang (2000), and Yeh & Sun (2002). Using these protcols as case studies, we demonstrate previously unpublished flaws in these protocols. We may speculate that such errors could have been found by protocol designers if proofs of security were to be constructed, and hope this work will encourage future protocol designers to provide proofs of security
Zorotypus medoensis Hwang
No full textZorotypus medoensis Hwang <p>(Figs 6, 7)</p> <p> <i>Zorotypus medoensis</i> Hwang, 1976: 225.</p> <p> <b>Material examined.</b> 2 apteron ♂♂, 1 apteron ♀, 2 alate ♀♀, labeled: ‘ China, Xizang A. R. [= Tibet], Motuo Hsien [ffiRθ], Hanmi [R÷], 29°21’50’’N, 95°07’48’’E, under bark covered with moss, 15.vii.2013, 2100 m, Chao Wu leg.’ (pcWC, pcBW); 9 deälate ♀♀, labeled: ‘ China, Xizang A. R., Motuo Hsien, 80K, 29°39’18’’N, 95°29’25’’E, under bark, 2.viii.2013, 2100 m, Wen-Xuan Bi leg.’ (pcBW).</p> <p> <b>Biology.</b> All individuals were collected under barks of large fallen decomposing logs (Fig. 7).</p> <p> <b>Distribution.</b> Southwestern China: Xizang Autonomous Region.</p> <p> <b>Comments.</b> According to Hwang (1976), <i>Zorotypus medoensis</i> is very similar to <i>Z</i>. <i>sinensis</i> in general morphology, and can be separated from the latter only by the chaetotaxy of male sternum VIII, and form of the male genitalia. For comparative purposes, important diagnostic features of <i>Zorotypus medoensis</i> from the type locality are figured (Fig. 6). Both <i>Z</i>. <i>medoensis</i> and <i>Z</i>. <i>sinensis</i> lack a strongly elongate and coiled flagellum, indicating that these two species may be more closely related to <i>Z</i>. <i>ceylonicus</i> Silverstri from Sri Lanka (Hwang 1974: 427) than to the southeastern Asian and central American species that share this structure (see ‘Comparative diagnosis’ of <i>Z</i>. <i>hainanensis</i> sp. n. above, and Mashimo et al. 2013: 512).</p>Published as part of <i>Yin, Zi-Wei, Li, Li-Zhen & Wu, Chao, 2015, New and little known species of Zorotypus Silvestri (Zoraptera: Zorotypidae) from China, pp. 557-566 in Zootaxa 4007 (4)</i> on page 565, DOI: 10.11646/zootaxa.4007.4.6, <a href="http://zenodo.org/record/240040">http://zenodo.org/record/240040</a>
Nonuniqueness for the Kinetic Fokker-Planck Equation with Inelastic Boundary Conditions
No full textWe describe the structure of solutions of the kinetic Fokker-Planck equations in domains with boundaries near the singular set in one-space dimension. We study in particular the behaviour of the solutions of this equation for inelastic boundary conditions which are characterized by means of a coefficient r describing the amount of energy lost in the collisions of the particles with the boundaries of the domain. A peculiar feature of this problem is the onset of a critical exponent r(c) which follows from the analysis of McKean (J Math Kyoto Univ 2:227-235 1963) of the properties of the stochastic process associated to the Fokker-Planck equation under consideration. In this paper, we prove rigorously that the solutions of the considered problem are nonunique if r <r(c) and unique if rc<r1. In particular, this nonuniqueness explains the different behaviours found in the physics literature for numerical simulations of the stochastic differential equation associated to the Fokker-Planck equation. In the proof of the results of this paper we use several asymptotic formulas and computations in the companion paper (Hwang in Q Appl Math 2018).11Nsciescopu
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Retraction: Crystal structure of a Baeyer–Villiger flavin‐containing monooxygenase from Staphylococcus aureus MRSA strain MU50, William C. Hwang, Qingping Xu, Bainan Wu, Adam Godzik
No full textThe above article from Proteins: Structure, Function, and Bioinformatics, published online on 5 August 2014 in Wiley Online Library (http://onlinelibrary.wiley.com/doi/10.1002/prot.24661/full), has been retracted by agreement between William C. Hwang, Qingping Xu, Bainan Wu, Adam Godzik, the Editor‐in‐Chief, Bertrand E. Garcia‐Moreno, and Wiley Periodicals, Inc. The retraction has been agreed because submission was made without agreement from co‐author Adam Godzik
R 패리티 비보존 및 뉴트리노 질량에 관한 현상론
No full text학위논문(박사) - 한국과학기술원 : 물리학과, 2002.2, [ ii, 132 p. ]We study various phenomenological implications of R-parity violating interactions and neutrino masses in supersymmetric models. Supersymmetry has been introduced to solve the gauge hierarchy problem. Minimal Supersymmetric Standard Model requires extra discrete symmetry which would forbid the rapid proton decay. Models which conserve baryon number and allow for small lepton number violation
explain non-zero neutrino masses while avoiding rapid proton decay.
We first review the basic materials of supersymmetry and present the important consequences of R-parity violation. R-parity violating interactions can contribute to various low energy processes via the exchange of virtual superparticles. The upper limits on trilinear R-parity violating couplings can be deduced from such processes under the assumption of single coupling dominance. All these bounds are collected and systematically reviewed. We also dicuss the new contributions, which contains both bilinear and trilinear R-parity violating interactions, to the fermion EDM and several lepton number violating processes like μ→eγ↔, μ→eee, μ↔e conversion.
One loop contributions to the neutrino mass matrix in R-parity violating supersymmetric models are studied and expressed in terms of basis independent quantities. We investigate the possibility of explaining all the fermion mass hierarchy in terms of flavor U(1) symmetry, including the neutrino mass and mixing structure suggested by neutrino oscillation experiments. A general formulation of sneutrino - antisneutrino mixing phenomena is presented in the field theory approach and applied to the anomaly mediated supersymmetry breaking models and R-parity violating models.한국과학기술원 : 물리학과
Is renewable energy more favorable to diversity than conventional energy sources on R&D performance?
No full textDiversity is often key to solving challenging problems. It sparks creativity through embracing various perspectives. Energy transition and climate change are challenges that require significant creativity and innovative ideas. This study is designed to analyze if diversity in the workforce has a meaningful relation to research and development (R&D) performance of public renewable energy in South Korea, and possibly, to compare the diversity of the workforce and its relation to performance between power generation industries. Using 538 public R&D projects, this study analyzed intellectual and economic performance along with workforce diversity based on gender, age, educational background, and educational level. Among several findings in this study, this study found a positive relationship between gender diversity and intellectual performance but a negative relationship between age diversity and intellectual performance. In addition, a clear distinction was found between renewable energy and nuclear and thermal power in terms of the research workforce itself and its relation to performance.N
Hee Jin Hwang
No full text학위논문(박사)--아주대학교 일반대학원 :분자과학기술학과,2017. 2Chapter 1. General Introduction 1
1.1. Synthetic biology 2
1.2. Synthetic biology tools for metabolic engineering 3
1.2.1. DNA assembly method 3
1.2.2. Genome editing method 3
1.2.3. Promoter engineering 4
1.2.4. Metabolite sensor 5
1.3. Protein engineering 6
1.4. Biochemical production in E.coli 7
1.5. Aims of this study 9
Chapter 2. Protein Engineering of Butyraldehyde Dehydrogenase for Enhancing Production of 1,4-Butanediol 10
2.1. Abstract 11
2.2. Introduction 12
2.3. Materials and methods 15
2.3.1. Bacterial strains, plasmids, and growth conditions 15
2.3.2. Construction of synthetic expression modules 15
2.3.3. Error-prone PCR mutagenesis and screening 16
2.3.4. Site-directed mutagenesis 17
2.3.5. Expression of proteins 17
2.3.6. Purification of proteins 17
2.3.7. Enzyme assays 18
2.3.8. Fermentation conditions 19
2.3.9. Analytical methods 19
2.3.10. Computational methods 20
2.4. Results and discussion 25
2.4.1. Selection of bld and bdh of C. saccharoperbutylacetonicum 25
2.4.2. Directed evolution of Bld 27
2.4.3. Analysis of Bld mutants 30
2.4.4. Second-generated Bld L273X mutants 34
2.4.5. Enzyme assays for wild-type Bld, L273I, and L273T 37
2.4.6. 1.4-BDO Production in knock-out strain 39
2.5. Conclusion 41
Chapter 3. Application of an Oxygen-Inducible nar Promoter System for Production of D-Lactate, 2,3-Butanediol and 1,3-Propanediol 42
3.1. Abstract 43
3.2. Introduction 44
3.3. Materials and Methods 48
3.3.1. Strains and plasmids 48
3.3.2. Media and Cultivation 49
3.3.3. Protein analysis 50
3.3.4. Fluorescence analysis 50
3.3.5. Metabolite analysis 51
3.4. Results and discussion 56
3.4.1. Evaluation of nar promoter using GFPm as a reporter protein 56
3.4.2. Production of D-lactate by the nar promoter 58
3.4.3. Production of (R,R)-2,3-BDO by the nar promoter 61
3.4.4. Production of 1,3-PDO by the nar promoter 64
3.5. Conclusion 67
Chapter 4. Development and Application of Synthetic nar Promoters for Production of D-Lactate and 2,3-Butanediol 68
4.1. Abstract 69
4.2. Introduction 70
4.3. Materials and Methods 72
4.3.1. Strains 72
4.3.2. Construction of synthetic promoter library 72
4.3.3. Manipulation of plasmids 72
4.3.4. Screening of the promoter library 73
4.3.5. Production of D-lactate and 2,3-BDO 74
4.3.6. Transcriptional analysis 75
4.3.7. Protein analysis 75
4.3.8. Fluorescence analysis 76
4.3.9. Metabolite analysis 76
4.4. Results and discussion 83
4.4.1. Construction and screening of the synthetic nar promoter library 83
4.4.2. Promoter strength analysis of the synthetic promoters by GFP fluorescence intensity 86
4.4.3. Characterization of the selected synthetic promoters 88
4.4.4. Production of D-lactate with synthetic promoter 91
4.4.5. Production of acetoin and 2,3-BDO with synthetic promoters 94
4.5. Conclusion 98
CONCLUSIONS 100
REFERENCE 102
ABSTRACT IN KOREAN 114
ACKNOWLEDGEMENTS 117DoctoralIn metabolic engineering, a number of heterologous genes are introduced in host strains, such as Escherichia coli and Saccharomyces cerevisiae, for production of natural products, chemicals and fuels. However, microbial cell factories have problems to be solved in order to produce high yields of target products. Especially, when a metabolic pathway is constructed using heterologous genes, which is a non-natural substance, low gene expression and low enzyme activity result in low production yield. Recently, synthetic biology tools have been used to overcome these problems. In this thesis, I have been carried out as followings: 1) securing of Bld mutants to be used to replace AdhE2 in 1,4-butanediol (BDO) biosynthesis pathway, 2) establishing applicability of the nar promoter for metabolic engineering to replace the inducible promoter, and 3) enhancing biochemical production through the synthetic nar promoter.
First, adhE2, a gene used in the 1,4-BDO biosynthetic pathway, was replaced with a bld gene. The production of 1,4-butanediol using both Bld and Bdh enzymes was lower than AdhE2. However, 1,4-BDO production was increased due to BldL273I, a mutant of Bld obtained through directed evolution. BldL273T, which is a mutant secured through saturated mutagenesis, produced an approximately 4-fold higher production than wild-type Bld. Genomic editing of E. coli also produced minimal byproducts and increased 1,4-BDO production. In engineered E.coli, AdhE2 produced 180 ± 30 mg/L of 1,4-BDO and BldL273T produced 660 ± 40 mg/L of 1,4-BDO, approximately 3.6-fold higher. Second, a dissolved oxygen (DO) dependent nar promoter was applied to the biosynthesis pathway of the target product in order to overcome the disadvantages of inducible promoters, including chemical inducer cost and abrupt changes of the microbial environment. To confirm the applicability of the nar promoter under micro-aerobic conditions, the D-lactic acid, (R, R)-2,3-butanediol (2,3-BDO) and 1,3-propanediol (1,3-PDO) biosynthesis pathways were used. The production of D-lactic acid, (R, R)-2,3-BDO and 1,3-PDO were 113.12 ± 2.37 g/L, 48.0 ± 8.48 g/L and 15.8 ± 0.62 g/L, respectively. These results were higher production than other reported production in E.coli and, confirmed that the nar promoter could be used for metabolic engineering. Finally, biosynthesis pathway genes under the control of the synthetic nar promoter libraries were fine-tuned to improve biochemical production. The synthetic nar promoter library was selected using GFP as a reporter protein, and three promoters were selected. The pathway enzymes were regulated by each synthetic promoter. Production of D-lactic acid was 105.56 g/L with synthetic strong promoter in fed-batch fermentation. The combination of ilvBN encoding acetohydroxy acid synthase with synthetic strong promoter, BDH1 encoding butanediol dehydrogenase with synthetic strong promoter and aldB encoding acetolactate decarboxylase with synthetic weak promoter produced 87.95 g/L of (R,R)-2,3-BDO in fed-batch fermentation.
In conclusion, through DNA assembly, protein engineering and promoter engineering, secured BldL273T produced improved production of 1,4-BDO, and the synthetic nar promoter as an alternative inducible promoter was used to fine-tuning gene expression for increasing biochemical production
Author Correction: Understanding the role of bitter taste perception in coffee, tea and alcohol consumption through Mendelian randomization
No full textAn amendment to this paper has been published and can be accessed via a link at the top of the paper. The original version of this Article contained an error in the author name Liang-Dar Hwang, which was incorrectly given as Daniel Liang-Dar Hwang
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