Computational Investigation of Mononuclear Iron Water Oxidation Catalyst Design

Hydrogen production from non-carbon sources is an essential component of clean and sustainable technology for reducing greenhouse gas emissions from fuels. Water oxidation, which splits water molecules into hydrogen (protons) and molecular oxygen, is a thermodynamically challenging, multistep reaction achieved in photosynthetic organisms via photocatalysis by the Oxygen Evolving Complex (OEC) of Photosystem II. Mononuclear water oxidation catalysts that aim to mimic nature typically rely on heavy, rare metals such as ruthenium and iridium. Replacing these metals with iron is particularly appealing because it is abundant, benign, and inexpensive. We use density functional theory to characterize the catalytic ability of mononuclear iron photocatalysts compared with their ruthenium counterparts for 20 different ligand modifications with varying degrees of electron withdrawing behavior. We quantify the energetics, bond lengths, and charges in each of the steps leading to the highest oxidation state of the metal and necessary O-O bond formation in a mechanism determined experimentally for ruthenium catalysts and in many ways analogous to that followed by the OEC. Although many of the iron catalysts exhibited prohibitively high redox potentials in achieving the highest oxidation state required by this mechanism, a few display promising energetics and stability at each step explored. These results provide insights regarding the feasibility and performance of water oxidation catalysts using earth abundant metals as well as pinpointing mechanistic steps where catalytic ability degrades

Preterm Infant Feeding and Cardiorespiratory Stability

Purpose: The primary purpose of this study was to investigate the effect of two different bottle feeding positions on a preterm infant's cardiorespiratory stability while feeding. Other factors associated with feeding success such as feeding duration, volume of consumption, gestational age, and day of life were also examined with respect to the feeding positions used. The long term objective for this line of investigation was to develop a neonatal intensive care unit feeding position protocol in order to decrease length of stay, improve oral feeding success, reduce health care costs, and prevent future feeding problems.Background: Of all live births in the United States, approximately 12% are to premature infants and of those born prematurely 90% will require admission to a neonatal intensive care unit (NICU). Although technological advances have improved preterm infant survival rates, they have failed to decrease medical costs and length of hospital stay. This is due mostly to the preterm infant's failure to oral feed successfully. As a result, research efforts tend to focus on oral feeding skills, the transition period from nasogastric to oral feeding, oral feeding readiness, and oral feeding advancement. However, little attention has been given to bottle feeding positions used and the preterm infant's cardiorespiratory stability.Methods: The study used a randomized, two-period, cross-over design to test Upright (45 degree head up) and Cradle (15 degree head up) feeding positions on cardiorespiratory stability. Feeding positions were administered by a NICU nurse on 12 medically stable, bottle feeding infants who were < 35 weeks gestational age.Results: Subject demographics were similar between each order grouping. Findings indicated that neither the Cradle nor the Upright feeding positions had a statistically significant effect on the preterm infant's cardiorespiratory stability. No significant relationships were found between feeding positions, volume of consumption, gestational age, and day of life as well. However, results suggested that preterm infants experienced a somewhat slower heart rate (p = .005), higher oxygen saturation level (p = .02), and although non-significant, a slightly shorter feeding duration (p = .27) when held in an Upright position as compared to the Cradle position

Insulated Solar Electric Cooker Immersion Heater

This report is the final design review (FDR) report for our team completing the Insulated Solar Electric Cooker (ISEC) Immersion Heater mechanical engineering senior project. The goal of this project is to standardize and perform analysis on a preexisting, inexpensive solar-powered immersion heater for cooking use in developing countries, reducing the adverse effects presented by traditional biomass cooking fires. We also designed a manufacturing process to improve repeatability and to reduce labor investment of heater production. The ISEC research team from the California Polytechnic State University Physics Department have been working on the development of this immersion heater and have produced working prototypes. Our task was to improve upon this design with a focus on conductive filler material and proper diode chain manufacturing, and to develop a manufacturing process that will allow these heaters to be made more efficiently and with fewer people in order to reduce manufacturing costs. As a result, we created specifications for the heater that that impacted the design and use of our manufacturing jig, which was created to aid the manufacture of the heater. Our preliminary analysis suggests that in order to extend heater lifetime and promote more effective heating of food, the temperature difference between the inside and the outside of the heater should be below 100℃. We were not able to produce heaters to meet this specification, but were able to make recommendations for how to proceed based on our findings. More detailed design specifications are included in this report, as well as background research and details regarding the manufacturing process for the immersion heater. With our manufacturing jig, our team was able to reduce the heater manufacturing time to approximately a quarter of the time taken previously. Additionally, our manufacturing jig allows for one person to perform the most cumbersome steps of the process alone. Also included are the final design, manufacturing plan, and cost analysis for a manufacturing jig to aid in heater manufacturing

Remdesivir for the Treatment of COVID-19: A Systematic Review of the Literature

In March 2020, the World Health Organization declared the spread of SARS-CoV-2 a global pandemic. To date, coronavirus disease-2019 (COVID-19) has spread to over 200 countries, leading to over 1.6 million cases and over 99,000 deaths. Given that there is neither a vaccine nor proven treatment for COVID-19, there is currently an urgent need for effective pharmacotherapy. To address the need for an effective treatment of SARS-CoV-2 during the worldwide pandemic, this systematic review of intravenous (IV) remdesivir was performed. Remdesivir, an anti-viral prodrug originally developed to treat Ebola virus disease, has shown broad spectrum activity against the Coronavirus family. A recent case report reported improvement of clinical symptoms with remdesivir in a patient with COVID-19. After conducting a systematic search of 18 clinical trial registries and three large scientific databases, we identified 86 potentially eligible items. Following removal of duplicates (n = 21), eligible studies were reviewed independently by two authors. After the first round of screening, inter-rater agreement was 98.5% (κ = 0.925). After the second round of full-text screening, inter-rater agreement was 100%. A total of seven ongoing and recruiting clinical trials of remdesivir (100-200 milligrams, intravenous [IV]) were included. We identified the following primary outcomes: patients discharged (n = 2); time to clinical status improvement (n = 2); improved O2 saturation (n = 2); body temperature normalization (n = 2); and clinical status (n = 1). Secondary outcomes in all identified studies included documentation of adverse events. Phase 3 trials are expected to be completed between April 2020–2023. Therefore, despite supportive data from in vitro and in vivo studies, the clinical effectiveness of IV remdesivir for treatment of COVID-19 and potential side effects remain incompletely defined in the human population

Handcuffing the Vote: Diluting Minority Voting Power Through Prison Gerrymandering and Felon Disenfranchisement

For the purposes of legislative redistricting, Texas counts prison populations at the address of the prison in which they are incarcerated at the time of the census, rather than their home prior to incarceration—regardless of whether the prisoners themselves maintain a residence in their home communities and intend to return home after incarceration. This deprives those home communities of full representation in the redistricting process. Combined with Texas’s felon disenfranchisement laws, this also results in arbitrarily bolstering the representational power of some Texans on the backs of other Texans who themselves are unable to vote. All of this takes place against the backdrop of a long history of unconstitutional racial discrimination by the State of Texas and a broken criminal justice system. Some states have taken proactive policy measures to remedy the systemic problem of prison gerrymandering, and changing societal values might pave the way for new legal challenges to combat these injustices

Exploring the Vid : a critical analysis of the form and its works

This project asks what a fanvid (vid) is, and by extension, what vids are to television. Vids are derived from television and film sources but they are themselves neither television episodes nor films. These works approximate the music video in appearance and duration, but are non-commercial fan works which construct creative and critical analyses of existing media. Vids remake narratives for a deeply attentive fan audience who watch with a deep knowledge of the source text, or with familiarity of the codes and conventions of the vid form. This thesis is concerned with vids of live-action narrative fiction and covers technological changes from broadcast television, to VCR and the rise of home video, to digital viewership. The chapters focus on different aspects of the vid form in relation to current issues in television studies, with some recourse to the growing field of fandom studies to provide appropriate subcultural context. The first case study chapter addresses contrasting theoretical understandings of collections and archives to contextualise the kinds of archival work done by vidders as a form of historiography. Vids are created from personal archives of film, television and other media sources; vids bear traces of their archival origins, and their creation is the performance of the vidder’s knowledge of their own archive. This chapter includes vids from the VCR era, and has a particular focus on Star Trek. The next chapter addresses multifandom vids – a vid genre that draws together video clips from several sources to compare and contrast norms of representation – alongside critical work on found footage films, to analyse the visual pleasures of vids and their relationship with audience fascinations (of erotics, of spectacle, etc.). The final chapter is an intensive case study of a trilogy of Battlestar Galactica vids, to analyse both the vid’s relationship with adaptation and genre, and the central role of songs in vids. While vids rely heavily on their soundtrack to structure meaning within the work, they are not abstract illustrations of songs. Instead, the clichés and idioms of the chosen song’s instrumentation are vital in completing the vid’s reinterpretation of its source text. Television studies is an appropriate disciplinary frame for studying the vid, as it offers ways of thinking about audiences, sequential narratives and the textuality of video forms. The creators and audiences of vids are highly competent in the deep reading and careful viewing of both mainstream and cult television and film, and keep archives of media which they reframe and re-present

Cytolytic toxin production by \u3ci\u3eStaphylococcus aureus\u3c/i\u3e is dependent upon the activity of the protoheme IX farnesyltransferase

Staphylococcus aureus is a medically important pathogen with an abundance of virulence factors that are necessary for survival within a host, including the production of cytolytic toxins. The regulation of toxin production is mediated by the Agr quorum sensing system, and a poorly defined post-exponential growth phase signal independent of Agr. As part of a recent genome wide association study (GWAS) to identify novel loci that alter the expression of cytolytic toxins, a polymorphism in the cyoE gene, which encodes a protoheme IX farnesyltransferase, was identified. This enzyme is essential for processing heme into the electron transport chain for use as an electron acceptor. Interestingly, without this enzyme S. aureus were repressed in their ability to secrete cytolytic toxins, and this appears to be mediated through repression of the Agr quorum sensing system. We hypothesize that the loss of electron transport is inducing feedback inhibition of metabolic capabilities that suppress the TCA cycle, and that this coupled with decreased RNAIII transcription prevents synthesis of cytolytic toxins