Synthesis of a Glutathione Analogue Using 2-α-Methyl-β-Cysteine

Inhibitors of glutathione reductase (GR) have been synthesized and studied in order to reverse an increasing trend in resistance to common malaria treatments. Analogues of glutathione (GSH) are being synthesized in order to increase resistance to proteolysis, thereby acting as an inhibitor of GR. Through the use of unnatural amino acids, solution-phase synthesis of GSH can be easily performed using modified cysteine (Cys) residues. A modified Cys residue, 2-α-methyl-β-cysteine, has been successfully synthesized, and coupling of this residue with the other required residues of GSH, glycine (Gly) and glutamic acid (Glu), has the potential to be successfully synthesized in good yields, thereby creating a stable GSH analogue

A W-String Realization of the Bosonic String

It has recently been shown that the ordinary bosonic string can be represented by a special background of N=1 or N=2 strings. In this paper, it will be shown that the bosonic string can also be represented by a special background of $W$-strings.Comment: 8 pages plain Tex, KCL-TH-93-1

Machine Learning Hub for Tapis

"Machine learning is indispensable for extracting insights from intricate datasets, expediting data analysis, and enabling cross-disciplinary decision-making. However, the complexity of machine learning models can hinder non-technical users, necessitating for user-friendly tools. Within the Cloud and Interactive Computing group (CIC) at the Texas Advanced Computing Center (TACC), we are actively developing a Machine Learning Hub (ML Hub) API for the Tapis Framework. Comprising accessible microservices, each with an independent REST API implemented in Python's Flask and codified with OpenAPI v3 definitions, our research aims to enhance the experiences of developers, scientists, and researchers. The integration of Hugging Face's API into ML Hub provides open-source pre-trained models for state-of-the-art AI capabilities. Currently, ML Hub's Models Overview and Models Download functions offer a gateway for non-technical users to explore and download machine learning models, authenticated using a JSON Web Token (JWT) from the Tapis Authenticator API. Future developments encompass implementing the Inference Client and Training Engine, seamlessly integrating with the Tapis UI in React and Typescript. Key features of ML Hub: 1. Models Overview: A portal showcasing top Hugging Face models with filtering options. 2. Models Download: Users can obtain specific models, with options to either download a binary file of the model or a zip file containing the model's repository, cached in a version-aware manner. 3. Inference Client: Facilitating server initiation for machine learning model inference on TACC's HPC cluster, enabling rapid prototyping. 4. Training Engine: Enabling users to fine-tune models and showcase them on TACC's HPC cluster, removing technical complexities. This research contributes to the broader discourse on democratizing machine learning's potential, by providing user- friendly access to state-of-the-art models and addressing non-technical users' challenges. We hope that this project will foster innovative collaboration and user engagement, paving the way for an inclusive and impactful future in machine learning research."Texas Advanced Computing Center (TACC

Oceanographic and Geomagnetic Influences on Sea Turtle Migrations

The research presented here explores the migratory behavior of sea turtles from behavioral, ecological, and evolutionary perspectives. Turtles display long-distance migratory movements at all stages of their lives; as hatchlings they migrate offshore from nesting beaches, as juveniles they navigate oceanic gyres, and as adults they move between foraging and reproductive grounds. For each of these migrations I examine how behavioral processes mediate large-scale biogeographic patterns. Analyses revealed a relationship between sea turtle nest abundance and offshore oceanic conditions. A disproportionate number of nests were deposited on beaches near ocean currents that facilitate the successful migration of hatchling turtles. This nesting pattern may persist through time because turtles return to nest near their natal beaches; thus, areas that produce the most surviving hatchlings and juveniles might also have the highest number of adults returning to nest. Laboratory experiments demonstrated that young turtles are capable of extracting latitudinal and longitudinal information from the earth's magnetic field to assess their position along their open ocean migration. Computer simulations indicated that even limited swimming in response to these magnetic cues exerts considerable influence on the open-ocean distribution of turtles. Specifically, magnetic navigation behavior appears to increase the number of turtles that encounter high-productivity foraging grounds and decrease the number that enter or remain in suboptimal oceanic regions. Additionally, the synthesis of results from a decade of behavioral assays on magnetic navigation in turtles, combined with geomagnetic and ocean circulation models, provided the first quantitative insight into how environmental conditions select for the evolution of this behavior. Finally, geomagnetic models were used to explore the long-standing mystery of how female turtles return to their natal beach after dispersing thousands of kilometers over a decade or more. Analyses indicate that a simple strategy of imprinting on the magnetic field of the natal site and using this information to return at maturity can account for the known homing precision of several different species of sea turtles. Moreover, the predictions from this hypothesis are consistent with the population structure for numerous sea turtle nesting assemblages across the world, as well as other spatiotemporal patterns in nest abundance.Doctor of Philosoph

Remedying contact dermatitis in broiler chickens with novel flooring treatments

Simple Summary Contact dermatitis is an overarching term for inflamed or necrotic lesions after contact with an allergen or irritant. Broiler chickens commonly experience these lesions due to prolonged contact with moisture, feces, and ammonia within litter. This study aimed to find methods to prevent and remedy lesions on broilers' feet, hocks, and breast. Furthermore, the impact of treatments on plumage cleanliness, gait, and body weight was investigated. We applied novel flooring treatments consisting of plastic slats and disinfectant mats containing povidone-iodine, which we compared to the industry control (used litter) and a positive control (clean litter). Weekly measurements on a sample of birds in each pen showed us the impact of both flooring treatments and age (weeks) on animal welfare outcomes. Contrary to expectations, the novel flooring treatments did not prevent or remedy contact dermatitis. In fact, the positive control, consisting of replacing litter every four days, resulted in the best welfare condition, with limited to no contact dermatitis at week seven of age. Contact dermatitis (footpad dermatitis (FPD), hock burns, and breast dermatitis) is a welfare issue for broiler chickens, causing pain and behavioral restrictions. Once lesions develop, often nothing is done to remedy the issue for the affected flock. Our objective was to evaluate novel flooring treatments at the flock level by providing preventative and remedial treatments against contact dermatitis, plumage soiling, and gait impairment. Broilers (n = 546) were housed in 42 pens, with 13 birds/pen. The flooring treatments (four) included used litter (NEG), new pine shavings replaced regularly (POS), a mat filled with 1% povidone-iodine solution (MAT), and the iodine mat placed on a slatted floor (SLAT). Flooring treatments were provided from day one of age (preventative approach; PREV) or day 29 (remedial approach; REM). Contact dermatitis, soiling, gait, and weight were recorded weekly (seven birds/pen). Results showed a treatment effect for all measures, dependent on bird age. Overall, the POS treatment resulted in the best welfare outcomes (FPD, hock burns, and gait). The worst contact dermatitis was found in the MAT and SLAT groups. NEG birds showed little contact dermatitis, opposite to expectations. Weights were lower for PREV-POS in week seven only. The treatments with povidone-iodine were deemed ineffective against contact dermatitis. Access to clean litter prevented and remedied contact dermatitis, and a comparable approach may be commercially feasible

Carbon Sources, Sinks and Offsets in Global Forest Investments

Global Forest Partners (GFP) is a forestry investment advisor that manages over 750,000 hectares of timberland around the globe on behalf of their investors. The primary objective of this analysis was to quantify GFP’s annual net carbon footprint, including both carbon sequestration occurring through their forest assets as well as the emissions that are attributable to the company. Additionally, we will provide a modeling tool with which GFP can continue to monitor their carbon impact in the coming years. We structured our carbon footprint analysis based on the methodology established by the California Air Resources Board for use in the California cap-and-trade system and the methodology used in the Verified Carbon Standard for global voluntary carbon markets. After performing our carbon accounting analysis, we sought to provide a global perspective of carbon pricing mechanisms. Due to low carbon prices, historic volatility within global carbon markets, and impending large-scale changes within international carbon trading, it does not appear to be pressing for GFP to pursue a monetization of their carbon sequestration at present. In order to properly prepare for an impending phase of expansion and interconnectedness in the global carbon marketplace, we recommend that GFP begin considering the potential carbon additionality impacts of future acquisitions. GFP should also take steps during its asset evaluation process to determine whether undertaking a forestry carbon offset project in any of its existing forests would be feasible from a regulatory and financial standpoint. Key trends to anticipate include the establishment of a Chinese emissions trading scheme by 2020, a potential increase in carbon trading within the United States, and a potential increase in international carbon trading as a result of the 2015 Conference of Parties 21 talks. As a result of this project, GFP will gain a firm foundation of knowledge regarding the methods involved in calculating forest carbon sequestration, evaluating additionality, assessing the value proposition for forestry carbon offset projects, and understanding the operation and outlooks of major global carbon markets.Master of Science (MS)Natural Resources and EnvironmentUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/117635/1/Carbon_Sources,_sinkes,_and_offset_in_global_forest_FINAL.pd

Coal dust explosibility meter evaluation and recommendations for application

"This report details the results of a NIOSH investigation on the ability of the Coal Dust Explosibility Meter (CDEM) to accurately predict the explosibility of samples of coal and rock dust mixtures collected from underground coal mines in the U.S. The CDEM, which gives instantaneous results in real time, represents a new way for miners and operators to assess the relative hazard of dust accumulations in their mines and the effectiveness of their rock dusting practices. The CDEM was developed by the National Institute for Occupational Safety and Health (NIOSH) and successfully underwent national and international peer review. The intention of the device is to assist mine operators in complying with the Mine Safety and Health Administration (MSHA) final rule 30 CFR* 75.403, requiring that the incombustible content of combined coal dust, rock dust, and other dust be at least 80% in underground areas of bituminous coal mines. As a final step towards commercialization of the CDEM, and to evaluate the performance of the device as a potential compliance tool, NIOSH undertook an extensive cooperative study with MSHA. This study, completed in 2009-2010, involved field use of the CDEM within MSHA's 10 bituminous coal districts. As part of their routine dust compliance surveys in these districts, MSHA inspectors collected sample coal and rock dust mixtures, field testing these samples for explosibility with the CDEM. Samples were then sent to the MSHA National Air and Dust Laboratory at Mt. Hope, WV, for parallel testing, first using a drying oven to determine the moisture followed by the traditional low temperature ashing (LTA) method. The LTA method determines explosibility of a coal and rock dust sample in a laboratory by heating the mixture to burn off the combustible material. The results, when combined with the moisture, are reported as total incombustible content (TIC). If the TIC is . 80%, the sample is deemed to be nonexplosible and compliant with 30 CFR 75.403. In the field component of this study, MSHA's use of the CDEM indicated that 30% (175) of the 591 samples collected were explosible. NIOSH was able to obtain and remeasure 297 samples, and 97% of those identified by the CDEM as being explosible (27% of samples) or nonexplosible (73% of samples) correlated with the results of the subsequent lab analysis using the LTA method. Of the remaining 3% where there were differences between the field and laboratory methods, subsequent NIOSH evaluation attributed these differences to the variability (incomplete mixing, inadequate drying of the sample, the particle size of the rock dust and/or coal dust) of the samples being analyzed, the retained moisture in those samples, and the inherent ash in the coal. In considering these results and comparing the CDEM field measurements to the LTA laboratory measurements, it is important to understand the fundamental distinctions between the two methods. The determination of TIC by the LTA method is not itself a direct measure of explosibility, but a surrogate that calculates a single parameter associated with full-scale experimental results. This method is not based on particle size and treats all particles equally regardless of the size. In contrast, the CDEM utilizes a different approach, using optical reflectance to determine the ratio of rock dust to coal dust in a mixture, with full-scale experiments on flame propagation having already demonstrated the effects of varying the coal dust particle sizes and incombustible concentrations on the explosible vs. nonexplosible dust mixtures. A final important distinction between the two methods is that the CDEM offers real-time measurements of the explosion propagation hazard within a coal mine entry, allowing for immediate identification and mitigation of the problem, while the results from the traditional LTA method are not known for days or weeks after a sample is collected, allowing for the deficiency in rock dust to continue. The conclusions of this study strongly support the field use of the CDEM to measure the explosibility of coal and rock dust mixtures, to more effectively improve the onsite adequacy of rock dusting for explosion prevention. Mine operators could use the CDEM on a regular basis to ensure that their rock dusting practices are achieving inertization requirements and meeting the intent of 30 CFR 75.403. MSHA inspectors could use the CDEM as a tool to immediately identify onsite explosibility hazards and initiate corrective action. A critical issue to both the LTA and the CDEM analysis methods is that the results are dependent on representative samples being collected for analysis." - NIOSHTIC-2Executive summary -- Introduction -- Background on coal dust and explosibility testing -- CDEM 0peration -- Comparison of laboratory results and CDEM results -- Joint study between NIOSH and MSHA -- Results and discussion -- GREEN measurements -- RED/YELLOW measurements -- Conclusions from the NIOSH study -- Commercial CDEM development -- Calibration and programming of the commercial CDEM -- Commercial CDEM changes based on potential customer concerns -- The Commercial CDEM as a verification and compliance tool -- NIOSH recommendations -- Acknowledgments -- References -- APPENDIX A: CDEM design -- APPENDIX B: CDEM training -- APPENDIX C: Prototype CDEM calibration and testing procedures used in the joint study -- APPENDIX D: Particle size effect -- APPENDIX E: MSHA inspector questions and commentsMarcia L. Harris, Michael J. Sapko, Floyd D. Varley, and Eric S. Weiss"August 2012."Also available via the World Wide Web.Includes bibliographical references (p. 25-26)