1,223 research outputs found
Mechanistic interrogations of ribosomal and non-ribosomal natural product enzymes
No full textDescribed herein is my thesis work towards structural and biochemical characterization of bacterial proteins involved in metabolite regulation and natural product biosynthesis. In the first case, I will describe the structural basis for transcriptional regulation of a small molecule metabolite, p-coumarate, and the remaining cases involve enzymes responsible for biosyntheses of complex natural products. Among the natural product cases are those falling under the class of ribosomally synthesized and post-translationally modified peptides (RiPPs), with a particular emphasis on the thiopeptide subclass of RiPPs. Additionally, characterization of an off-loading enzyme involved in hybrid polyketide/non-ribosomal peptide (PK-NRP) natural product biosynthesis is described.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2021-05-01The student, Dillon Cogan, accepted the attached license on 2019-04-03 at 18:53.The student, Dillon Cogan, submitted this Dissertation for approval on 2019-04-03 at 19:08.This Dissertation was approved for publication on 2019-04-08 at 16:47.DSpace SAF Submission Ingestion Package generated from Vireo submission #13487 on 2019-08-22 at 16:20:40Made available in DSpace on 2019-08-23T20:44:38Z (GMT). No. of bitstreams: 2
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Previous issue date: 2019-04-08Embargo set by: Seth Robbins for item 112279
Lift date: 2021-08-23T20:44:50Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 112279
Lift date: 2021-08-23T20:46:41Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 112279
Lift date: 2021-08-23T20:47:38Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 112279
Lift date: 2021-08-23T20:48:32Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 112279 on 2021-08-24T09:15:38Z
“Ready to Be a Normal Person Again”: Occupational Needs of Service Members With Mild Traumatic Brain Injury
No full textAbstract
Date Presented 4/1/2017
The purpose of this study is to describe the occupational challenges in daily life faced by active duty military service members who experience persistent symptoms following mild traumatic brain injury. The findings establish needs that fall within each aspect of the occupational therapy domain of practice.
Primary Author and Speaker: Alison Cogan
Contributing Authors: Maria Devore, Christine Haines, Karla Lepore, Margaret Ryan</jats:p
Oldest allies, guarded friends the United States and France since 1940
No full textOffering a revisionist-style look at the French-American relationship, Charles G. Cogan presents a series of case studies dating from the "great misunderstanding" between the Roosevelt administration and the Free French movement in World War II to the formation of the Euro-Corps in the early 1990s. In struggling to regain France's leading position in Europe, the French leadership under Charles de Gaulle sought on the one hand an independent nuclear force, and, on the other, a strengthening of Europe with a Franco-German alliance at its core. Both of these policies provoked friction with the United States; both will now have to be revised, the author asserts, after the end of the Cold War and the emergence of a powerful, reunited Germany. The overall prospect, however, is that of continuing differences between France and the United States, as the antagonisms of the past, which date primarily from the World War II era, will not easily die out. Written by a former senior intelligence officer with a background of extensive French government and academic relationships, Oldest Allies, Guarded Friends will be invaluable to all students of contemporary European history and U.S. foreign relations
Thinking Small: Progress on Microscale Neurostimulation Technology
No full textFull text access from Treasures at UT Dallas is restricted to current UTD affiliates.Objectives: Neural stimulation is well-accepted as an effective therapy for a wide range of neurological disorders. While the scale of clinical devices is relatively large, translational, and pilot clinical applications are underway for microelectrode-based systems. Microelectrodes have the advantage of stimulating a relatively small tissue volume which may improve selectivity of therapeutic stimuli. Current microelectrode technology is associated with chronic tissue response which limits utility of these devices for neural recording and stimulation. One approach for addressing the tissue response problem may be to reduce physical dimensions of the device. "Thinking small" is a trend for the electronics industry, and for implantable neural interfaces, the result may be a device that can evade the foreign body response. Materials and Methods: This review paper surveys our current understanding pertaining to the relationship between implant size and tissue response and the state-of-the-art in ultrasmall microelectrodes. A comprehensive literature search was performed using PubMed, Web of Science (Clarivate Analytics), and Google Scholar. Results: The literature review shows recent efforts to create microelectrodes that are extremely thin appear to reduce or even eliminate the chronic tissue response. With high charge capacity coatings, ultramicroelectrodes fabricated from emerging polymers, and amorphous silicon carbide appear promising for neurostimulation applications. Conclusion: We envision the emergence of robust and manufacturable ultramicroelectrodes that leverage advanced materials where the small cross-sectional geometry enables compliance within tissue. Nevertheless, future testing under in vivo conditions is particularly important for assessing the stability of thin film devices under chronic stimulation.The Space and Naval Warfare Systems Center, Pacific Grant/Contract No. HR0011-15-2-0017 and NIH grant U01NS090454-01Erik Jonsson School of Engineering and Computer Scienc
Electrodeposited Iridium Oxide on Carbon Fiber Ultramicroelectrodes for Neural Recording and Stimulation
No full textHost encapsulation decreases the ability of chronically implanted microelectrodes to record or stimulate neural activity. The degree of foreign body response is thought to depend strongly on the cross-sectional dimensions of the electrode shaft penetrating neural tissue. Microelectrodes with cellular or sub-cellular scale shaft cross-sectional dimensions, such as carbon fiber ultramicroelectrodes have been previously demonstrated to elicit minimal tissue response, but their small geometric surface area results in high electrode impedances for neural recording, and reduced charge injection capacity during current pulsing for neural stimulation. We investigated electrodeposited iridium oxide films (EIROF) on carbon fiber ultramicroelectrodes as a means of enhancing the charge injection capacity and reducing electrode impedance. EIROF coatings reduced the electrode impedance measured at 1 kHz by a factor of 10 and improved charge storage and charge injection capacities. The maximum charge injection capacity was also strongly dependent on the interpulse bias and pulse width, and reflected a potential-dependent EIROF impedance. The charge injection capacity of the EIROF-coated carbon fiber ultramicroelectrodes measured in an inorganic buffered saline model of interstitial fluid exceeded 17 mC/cm2 with appropriate biasing, allowing charge-injection at levels well above reported charge/phase thresholds for intraneural microstimulation.NIH grant U01NS090454Erik Jonsson School of Engineering and Computer Scienc
The life and works of James Miller, 1704-1744, with particular reference to the satiric content of his poetry and plays.
No full textPhDJames Miller was born the son of a Dorset rector in 1704. He
was himself ordained, but acquired no benefice until just before his
early death, probably because of a scathing portrayal of the Bishop
of London in one of his verse satires. At Oxford he wrote a vivacious
comedy of humours, set in the University. Its production in 1730
began his dramatic career, at a time when the number of London
theatres had just doubled, and new dramatic forms were being invented.
In 1731 his poem Harlequin-Horace, a witty inversion of
the Ars Poetica, attacked pantomime and opera, but also painted a
lively portrait of the entire theatrical world, in the tradition of
the Dunciad.
After collaborating in a translation of Moliere's works Miller
wrote two plays based on this author. Of all his dramatic works
these were the most successful with his contemporaries, and were
followed by a modernisation of Much Ado, and a ballad-opera adapted
from an afterpiece by Jean-Baptiste Rousseau, and rendered highly
topical. Miller made similar use of a recent French comedy showing
a Red Indian's reactions to civilisation, a satiric "fable" by Walsh
and Voltaire's Mahomet. A large quantity of original material was
incorporated into most of these, and this is generally satirical in
nature. The Indian is made to voice almost egalitarian sentiments.
An afterpiece, "The Camp Visitants", satirised military inaction
in the war, and was apparently banned. The manuscripts of the six
plays produced after the Licensing Act bear the examiner's deletions,
and illustrate the nature of the censorship at this time.
Miller's greatest strength is probably his flexible, vigorously
colloquial dialogue. His political satire is mostly contained in
the poetry, which attacks Walpole's administration with increasing
vehemence through the seventeen-thirties, until its fall. In 1740
two poems that used Pope in symbolic contrast to Walpole caused a
sensation. In both poetry and plays Miller is also a social satirist,
who lays unusually strong emphasis on false taste and the deterioration
of culture
Music for classical guitar by South African composers : a historical survey, notes on selected works and a general catalogue
No full textIncludes abstract.Includes bibliographical references (leaves 296-309).This is the first comprehensive investigation of music for, or including, the classical guitar by South African composers. The focus of this research has been, firstly, to uncover as much of the repertoire as possible, and, secondly, to collate, study, catalogue and report on the information. A brief historical survey of the guitar in South Africa provides the context within which this study was conducted. The primary sources of quantitative data collection were through the archival catalogues of the South African Music Rights Organisation and through personal contact with guitarists, composers and guitar teachers. Other sources consulted were publishers, broadcasting corporations, recording companies, libraries and the internet. The body of the dissertation comprises biographical sketches, background notes, analyses and technical notes on 17 selected solo and chamber works dating from 1947 to 2007 by some of South Africa's most prominent composers and guitaristcomposers. The repertoire ranges in style from the traditional and ethnically inspired to the experimental and abstract. As this is an empirical survey, each selected entry includes details on instrumentation, duration, level of difficulty, number of pages, scordatura, commissions or requests, sources or publishers, premières and recordings. A biography of each composer is provided as well as background notes which offer an overview of the selected work. The notes discuss historical, cultural, musical and extra-musical influences, and frequently include references to interview material. The commentaries on the selected works, with musical examples, include an analytical component describing structure, form, stylistic and compositional elements, while the technical observations include performance suggestions and a grading for each work
Complex-systems design methodology for systems-engineering collaborative environment
No full textIn the last decades man-made systems have gained in overall complexity and have become more articulated than before. From an engineering point of view, a complex system may be defined as one in which there are multiple interactions between many different elements of the system and many different disciplines concurring to its definition. However, the complexity seen from the system perspective is only partial. In more general terms complexity does not only regard the system per se, but it is also related to the whole life-cycle management of the system. This encompasses all the activities needed to support the program development from the requirements definition to the verification, validation and operation of the system in the presence of a large number of different stakeholders. These two interrelated views of complexity, being bottom-up in the first case and top-down in the second, both converge to the system defined as an entity formed by a set of interdependent functions and elements that complete one or more functions defined by requirements and specifications. Systems Engineering processes have been increasingly adopted and implemented by enterprise environments to face this increased complexity. The purpose is to pursue time and cost reduction by a parallelization of processes and activities, while at the same time maintaining high-quality standards. From the life-cycle management point of view the tendency has been to rely more and more on software tools to formally applying modelling techniques in support of all the activities involved in the system life-cycle from the beginning to the end. The transition from document-centric to model-centric systems engineering allows for an efficient management of the information flow across space and time by delivering the right information, in the right place, at the right time, and to the right people working in geographically-distributed multi-disciplinary teams. This standardized implementation of model-centric systems engineering, using virtual systems modelling standards, is usually called Model Based Systems Engineering, MBSE. On the other side, looking at the problem from the perspective of the system as a product, the management of complexity is also experiencing a radical modification. The former adopted approach of sequentially designing with separate discipline activities is now being replaced by a more integrated approach. In the Aerospace-Engineering domain, for instance, designing with highly integrated mathematical models has become the norm. Already from the preliminary design of a new system all its elements and the disciplines involved over the entire life-cycle are taken into account, with the objective of reducing risks and costs, and possibly optimizing the performance. When the right people all work as a team in a multi-disciplinary collaborative environment, the MBSE and the Concurrent Engineering finally converge to the definition of the system. The main concern of the engineering activities involved in system design is to predict the behavior of the physical phenomena typical of the system of interest. The development and utilization of mathematical models able to reproduce the future behavior of the system based on inputs, boundary conditions and constraints, is of paramount importance for these design activities. The basic idea is that before those decisions that are hard to undo are made, the alternatives should be carefully assessed and discussed. Despite the favorable environment created by MBSE and Concurrent Engineering for the discipline experts to work, discuss and share knowledge, a certain lack of engineering-tool interoperability and standardized design methodologies has been so far a significant inhibitor, (International Council on Systems Engineering [INCOSE], 2007). The systems mathematical models usually implemented in the collaborative environments provide exceptional engineering-data exchange between experts, but often lack in providing structured and common design approaches involving all the disciplines at the same time. In most of the cases the various stakeholders have full authority on design issues belonging to their inherent domain only. The interfaces are usually determined by the experts and manually fed to the integrated models. We believe that the enormous effort made to conceive, implement, and operate MBSE and Concurrent Engineering could be consolidated and brought to a more fundamental level, if also the more common design analytical methods and tools could be concurrently exploited. Design-space exploration and optimization, uncertainty and sensitivity analysis, and trade off analysis are certainly design activities that are common to all the disciplines, consistently implemented for design purposes at the discipline-domain level. Bringing fundamental analysis techniques from the discipline-domain level to the system-domain level, to exploit interactions and synergies and to enable an efficient trade-off management is the central topic discussed in this chapter. The methodologies presented in this chapter are designed for their implementation in collaborative environments to support the engineering team and the decision-makers in the activity of exploring the design space of complex-system, typically long-running, models. In Section 2 some basic definitions, terminology, and design settings of the class of problems of interest are discussed. In Section 3 a test case of an Earth-observation satellite mission is introduced. This satellite mission is used throughout the chapter to show the implementation of the methods step by step. Sampling the design space is the first design activity discussed in Section 4. Then in Section 5 and Section 6 a general approach to compute sensitivity and to support the engineering team and decision makers with standard visualization tools are discussed. In Section 7 we provide an overview on the utilization of a unified sampling method for uncertainty and robustness analysis. Finally, we conclude the chapter providing some recommendations and additional thoughts in Section
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