An instrumental evaluation of selected metal functionalised semiconductors in the facilitation of photo-organic transformations.

Doctoral Degree. University of KwaZulu-Natal, Pietermaritzburg.Throughout this research study, various strategies to design, synthesise and test the photo-reactivity of attenuated wide band gap semiconductors in alcohol oxidation studies have been explored. An alizarin red-sensitised zinc oxide photocatalyst which was stabilised in a silver-sodium electrolyte effectively facilitated a broad aromatic and aliphatic alcohol oxidation table with reported conversions ranging from 10 to ≥ 99 %. A systematic characterisation of the alizarin red-sensitised zinc oxide investigated the photoelectronic migrations across the alizarin red–zinc oxide interface and detected the transfer of electrons from the highest occupied molecular orbital of alizarin to the defect site of zinc oxide at 507 nm. Further studies were directed towards the development of a novel titanium dioxide semiconductor that was activated by visible light. Three attempted strategies (pseudo perovskites [Cu3TiO5, Ni3TiO5, and Mn3TiO5], silver functionalised cadmium sulfide and a heterojunction between cadmium sulfide and titanium dioxide) explored the possibility of lowering the band gap potential of wide band gap semiconductors through metal ion functionalisation (Cu, Ni, Mn, and Ag) and heterojunction principles for the purpose of finding applications in mediating alcohol oxidations. Whilst the three strategies were unable to demonstrate viable photocatalytic properties, the instrumental insight obtained during the process identified a suitable three-component semiconductor system (Cu/Pd-N-TiO2). Cu/Pd-N-TiO2 was extensively characterised with an array of instrumental techniques, thus developing an in-depth understanding of the photophysical properties that governed the photo-oxidative transformation of a range of cyclic alcohols and in the remediation of two dyestuffs typically associated with environmental contamination

A study towards the use of semiconductors as mediators in organic oxidation transformations.

M. Sc. University of KwaZulu-Natal, Pietermaritzburg 2015.Abstract available in PDF file

In-Flight Evaluation of the Traffic Aware Planner on the NASA HU-25A Guardian Aircraft

NASAs Traffic Aware Planner (TAP) software is a research-prototype decision support tool that provides pilots with time- and fuel-saving route recommendations that optimize their current trajectory. The software runs on a first-of-a-kind system architecture onboard three aircraft in revenue service conducting operational evaluations with a major domestic airline. Therefore, significant NASA-internal testing is required prior to releasing the software to the partner airline. This paper describes a flight test plan that exercises the functionality of the TAP software in a representative operational environment, describes the system architecture developed and implemented for the NASA Langley HU-25A Guardian aircraft to support the test objectives, presents outcomes of the flight test campaign, and discusses use cases that demonstrate the value of flight testing for this activity.Research into flight path optimization of transport aircraft conducted by the National Aeronautics and SpaceAdministration (NASA) has produced an operational concept known as Traffic Aware Strategic Aircrew Requests(TASAR) [1, 2]. This near-term concept [3] provides the aircrew with a flight deck decision support tool known asthe Traffic Aware Planner (TAP). The TAP software leverages a growing number of information sources on the flightdeck to make time- and fuel-saving route optimization recommendations to the aircrew while en route. The aircrewcan then use the suggestions provided by the tool to make route change requests with a greater likelihood of acceptanceby air traffic control (ATC). Since TASAR is a concept intended for the current operational environment, it isintentionally designed to have no safety-critical impact or require any changes to current Federal AviationAdministration (FAA) rules and procedures [4, 5].The research prototype TAP system [68], explained further in Section III.C, continually incorporates up-to-dateaircraft state data from onboard avionics, as well as the latest position of surrounding traffic, the most recent windforecast, and the most recent convective weather forecast, in order to calculate candidate trajectory modifications thatimprove upon the current active route. These trajectories account for user-selectable objective functions [3] of reducedfuel burn, reduced flight time, or an airline-derived combination of factors known as trip cost. Previous analyses andsimulations have estimated substantial savings for airlines employing this technique within the U.S. National AirspaceSystem (NAS) [911]. Operational evaluations with Alaska Airlines seek to validate these projected benefits usingmeasured data while simultaneously providing benefits to the airline [12, 13].The TAP software has undergone a number of human-in-the-loop simulations [14] and flight test activities[1517] in order to validate the operational concept, evaluate human factors considerations (e.g., workload, usability,distraction, etc.), and to assess the ability of the software to function in a representative operational environment (e.g.,connected to live avionics data, using in-flight internet connectivity, etc.). However, these simulations and flight testcampaigns did not account for the hardware architecture implemented on the three aircraft for Alaska Airlinesoperational evaluations of the TAP software. Therefore, a need was identified to thoroughly test the functionality ofthe software in a similar hardware architecture to that of the partner airlines aircraft. Information regarding testapparatus and environments used to evaluate TAP prior to testing on the HU-25A can be found in reference [18].A campaign of flight trials on a NASA aircraft, the HU-25A Guardian, was conducted to ensure that the researchprototype TAP system functions well in a configuration similar to the Alaska Airlines aircraft prior to deployment.This airborne, networked environment enables an assessment of the operational factors unique to the flight environment. Additionally, this activity evaluated the effectiveness and benefit of new TAP functionality andoperation in a relevant flight environment while allowing the rapid prototyping of new concepts and features.This paper is organized as follows: Section II discusses the details of the flight test plan, flight profiles, and theduties of personnel involved with conducting flight operations. Section III describes the test platform, avionicsequipage, and system architecture. Section IV presents a discussion of results, and Section V contains concludingremarks

Expression of HOXDIO Gene in Normal Endometrium and Endometrial Adenocarcinoma

Objective: Hox genes encode DNA transcription regulatory that contain a conserved 61 amino acid protein called the homeodomain. Although best known for their role in cellular differentiation during embryonic development, aberrant expression of these genes has been associated with hematologic and solid neoplasms. The purpose of this study was to determine the relative expression of HOXD10 in huamn endometrial adenocarcionmas. Methods: mRNA was isolated from 7 normal endometrial specimens and 28 endometrial adenocarcinoma specimens. cDNA was synthesized using randon hexamer primers. The expression of HOXD10 relative to βtubulin (internal control) was assessed by densitometric comparison of co-amplified Phosphorus-32 (32P) labeled gene products separated by agarose gel electrophoesis. Direct sequencing of purified HOXD10 polymerase chain reaction product was also performed. Results: The sequence of the purified HOXD10 product corresponds to the known DNA sequence reported in the National Institutes of Health Gene Bank. mRNA expression of HOXD10 relative to β-tubulin is significantly lower in endometrial carcinomas than in normal endometrium. Furthermore, the ratio of HOXD10 to β-tubulin expression varies inversely with the histologic grade of the tumor (P = .0009). Conclusion: Cancer is a multistep proces involving aberrant expression of genes that regulate cell growth and differentiation. Human HOXD10 gene expression is altered in endometrial carcinoma and varies with the histologic grade of differentiation. This observation supports the theory that homeobox genes play a role in oncogenesis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69122/2/10.1177_107155769800500509.pd

Fluency Assistance Device (FAD): Masker Upgrades

There are around seventy million people internationally who have a stutter, a form of fluency disorder. Some fluency assistance devices are available to the public, but most are highly expensive or unreliable. The Fluency Assistive Device (FAD) team seeks to assist a niche community of these individuals for whom therapy has not worked, and who currently rely on a device known as the Edinburgh Masker. To best reach this community, FAD is partnering with Dave Germeyer, who has invaluable experience repairing these masker devices for his clientele. FAD is redesigning the masker to increase its portability, functionality, and cost-effectiveness by developing an improved analog and new digital version. The Analog Masker v1.3 focuses on updated components and consolidated circuitry to eliminate troublesome wiring of the original. The Digital Masker v1.0 employs a Bluetooth-enabled microcontroller to achieve masker functionality, offering the flexibility of alternative fluency assistance algorithms to assist a broader group of users. An updated prototype of the Analog Masker v1.3 was fabricated and tested for power consumption and overall functional output characteristics versus the original Edinburgh version. The Analog Masker v1.3 has also been fully packaged and enclosed to produce a client testable unit. Bluetooth audio output for the Digital Masker has almost been completed, and two of the alternative algorithms have been coded for the masking output. One of these algorithms, Delayed Altered Feedback (DAF), now produces the expected output in response to an audio test input. Clarity and integrity of the DAF signal output have also been improved. The Masking Altered Feedback (MAF) algorithm that emulates the behavior of the Edinburgh original on the Digital Masker v1.0 is under development. Funding for this work provided by The Collaboratory for Strategic Partnerships and Applied Research.https://mosaic.messiah.edu/engr2022/1006/thumbnail.jp

Loss of murine Paneth cell function alters the immature intestinal microbiome and mimics changes seen in neonatal necrotizing enterocolitis

Necrotizing enterocolitis (NEC) remains the leading cause of gastrointestinal morbidity and mortality in premature infants. Human and animal studies suggest a role for Paneth cells in NEC pathogenesis. Paneth cells play critical roles in host-microbial interactions and epithelial homeostasis. The ramifications of eliminating Paneth cell function on the immature host-microbial axis remains incomplete. Paneth cell function was depleted in the immature murine intestine using chemical and genetic models, which resulted in intestinal injury consistent with NEC. Paneth cell depletion was confirmed using histology, electron microscopy, flow cytometry, and real time RT-PCR. Cecal samples were analyzed at various time points to determine the effects of Paneth cell depletion with and without Klebsiella gavage on the microbiome. Deficient Paneth cell function induced significant compositional changes in the cecal microbiome with a significant increase in Enterobacteriacae species. Further, the bloom of Enterobacteriaceae species that occurs is phenotypically similar to what is seen in human NEC. This further strengthens our understanding of the importance of Paneth cells to intestinal homeostasis in the immature intestine

Whole-genome sequencing for national surveillance of Shiga toxin–producing Escherichia coli O157

Background. National surveillance of gastrointestinal pathogens, such as Shiga toxin–producing Escherichia coli O157 (STEC O157), is key to rapidly identifying linked cases in the distributed food network to facilitate public health interventions. In this study, we used whole-genome sequencing (WGS) as a tool to inform national surveillance of STEC O157 in terms of identifying linked cases and clusters and guiding epidemiological investigation. Methods. We retrospectively analyzed 334 isolates randomly sampled from 1002 strains of STEC O157 received by the Gastrointestinal Bacteria Reference Unit at Public Health England, Colindale, in 2012. The genetic distance between each isolate, as estimated by WGS, was calculated and phylogenetic methods were used to place strains in an evolutionary context. Results. Estimates of linked clusters representing STEC O157 outbreaks in England and Wales increased by 2-fold when WGS was used instead of traditional typing techniques. The previously unidentified clusters were often widely geographically distributed and small in size. Phylogenetic analysis facilitated identification of temporally distinct cases sharing common exposures and delineating those that shared epidemiological and temporal links. Comparison with multi locus variable number tandem repeat analysis (MLVA) showed that although MLVA is as sensitive as WGS, WGS provides a more timely resolution to outbreak clustering. Conclusions. WGS has come of age as a molecular typing tool to inform national surveillance of STEC O157; it can be used in real time to provide the highest strain-level resolution for outbreak investigation. WGS allows linked cases to be identified with unprecedented specificity and sensitivity that will facilitate targeted and appropriate public health investigations

Fibroblasts derived from oesophageal adenocarcinoma differ in DNA methylation profile from normal oesophageal fibroblasts

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.Oesophageal adenocarcinoma (OAC) is increasing in incidence and has a poor prognosis. Tumour derived fibroblasts (TDFs) differ functionally from normal fibroblasts (NDFs), and play a pivotal role in cancer. Many of the differences persist through subculture. We measured the DNA methylation profiles of 10 TDFs from OAC with 12 NDF from normal oesophageal mucosa using Infinium HumanMethylation450 Beadchips and found they differed in multidimensional scaling analysis. We identified 4,856 differentially methylated CpGs (DMCs, adjusted p  0.15), of which 3,243 (66.8%) were hypomethylated in TDFs compared to NDFs. Hypermethylated DMCs were enriched at transcription start sites (TSSs) and in CpG islands, and depleted in transcriptional enhancers. Gene ontology analysis of genes with DMCs at TSSs revealed an enrichment of genes involved in development, morphogenesis, migration, adhesion, regulation of processes and response to stimuli. Alpha-smooth muscle actin (α-SMA) is a marker of activated fibroblasts and a poor prognostic indicator in OAC. Hypomethylated DMCs were observed at the TSS of transcript variant 2 of α-SMA, which correlated with an increase in α-SMA protein expression. These data suggest that DNA methylation may contribute to the maintenance of the TDF phenotype