Miracle-dz/UniFAR-FTUs huggingface dataset:
Error Characterization, Channel Modeling and Coding for Flash Memories

NAND Flash memories have become a widely used non-volatile data storage technology and their application areas are expected to grow in the future with the advent of cloud computing, big data and the internet-of-things. This has led to aggressive scaling down of the NAND flash memory cell feature sizes and also increased adoption of flash memories with multiple cell levels to increase the data storage density. These factors have adversely affected the reliability of flash memories.In this dissertation, our main goal is to perform detailed characterization of the errors that occur in multi-level cell (MLC) flash memories and develop novel mathematical channel models that better reflect the measured error characteristics than do current models. The channel models thus developed are applied to error correcting code (ECC) frame error rate (FER) performance estimation in MLC flash memories and to estimating the flash memory channel capacity as represented by the channel models. We also utilize the characterization of inter-cell interference (ICI) errors to evaluate the performance of constrained coding schemes that mitigate ICI and improve the reliability of flash memories.In Chapter 5, which is self-contained, we propose and study modifications to adaptive linear programming decoding techniques applied to decoding polar codes. We also propose a reduced complexity representation of the polar code sparse factor graph, resulting in time complexity improvements in the adaptive LP decoder.
The reliability of South African real-time output gap estimates

Estimates of the output gap are an important component of policy-makersâ€™ toolkits. Both the theory underlying monetary policy analysis and the empirical models employed by central banks suggest that the output gap is a key variable explaining inflation. In this view, the estimate of the output gap provides not only an indication of how well the economy is operating relative to its potential, it also signals whether inflation is likely to increase or decrease in the future. The reliability of estimates of the output gap is therefore extremely important for policy making. However, a large literature has highlighted both conceptual and practical problems in measuring the gap, including the difficulty of using real-time data that will be revised in the future. The contribution of this paper is to assess the reliability of real-time estimates of the South African output gap, by estimating output gaps using a range of univariate methods applied to real-time gross domestic product (GDP) data. Consistent with the results of similar studies conducted in other countries, it is found that the real-time South African output gap estimates are in fact quite unreliable and are significantly revised over time. Furthermore, the source of these revisions is largely attributed to new data points becoming available, indicating the unreliability of end-of-sample estimates, rather than data or parameter revisions.
The Economic Effects of Interregional Trading of Renewable Energy Certificates in the U.S. WECC

In the U.S., individual states enact Renewable Portfolio Standards (RPSs) for renewable electricity production with little coordination. Each state imposes restrictions on the amounts and locations of qualifying renewable generation. Using a co-optimization (transmission and generation) planning model, we quantify the long run economic benefits of allowing flexibility in the trading of Renewable Energy Credits (RECs) among the U.S. states belonging to the Western Electricity Coordinating Council (WECC). We characterize flexibility in terms of the amount and geographic eligibility of out-of-state RECs that can be used to meet a state’s RPS goal. Although more trade would be expected to have economic benefits, neither the size of these benefits nor the effects of such trading on infrastructure investments, CO2 emissions and energy prices have been previously quantified. We find that up to 90% of the economic benefits are captured if approximately 25% of unbundled RECs are allowed to be acquired from out of state. Furthermore, increasing REC trading flexibility does not necessarily result in either higher transmission investment costs or a substantial impact on CO2 emissions. Finally, increasing REC trading flexibility decreases energy prices in some states and increases them elsewhere, while the WECC-wide average energy price decreases.
Identification of Intermediate and Branch Metabolites Resulting from Biotransformation of 2-Benzoxazolinone by Fusarium verticillioides

ABSTRACT Detoxification of the maize (Zea mays) antimicrobial compound 2-benzoxazolinone by the fungal endophyte Fusarium verticillioides involves two genetic loci, FDB1 and FDB2, and results in the formation of N-(2-hydroxyphenyl)malonamic acid. Intermediate and branch metabolites were previously suggested to be part of the biotransformation pathway. Evidence is presented here in support of 2-aminophenol as the intermediate metabolite and 2-acetamidophenol as the branch metabolite, which was previously designated as BOA-X. Overall, 2-benzoxazolinone metabolism involves hydrolysis (FDB1) to produce 2-aminophenol, which is then modified (FDB2) by addition of a malonyl group to produce N-(2-hydroxyphenyl)malonamic acid. If the modification is prevented due to genetic mutation (fbd2), then 2-acetamidophenol may accumulate as a result of addition of an acetyl group to 2-aminophenol. This study resolves the overall chemistry of the 2-benzoxazolinone detoxification pathway, and we hypothesize that biotransformation of the related antimicrobial 6-methoxy-2-benzoxazolinone to produce N-(2-hydroxy-4-methoxyphenyl)malonamic acid also occurs via the same enzymatic modifications. Detoxification of these antimicrobials by F. verticillioides apparently is not a major virulence factor but may enhance the ecological fitness of the fungus during colonization of maize stubble and field debris.
Comparative analysis of the pC194 group of rolling circle plasmids.

pC194-type plasmids have been isolated from widely divergent species of bacteria: Gram positive, Proteobacteria, Spirochaetes and Cyanobacteria. We have examined the three essential replication elements of these plasmids, i.e., the Rep protein, and the origins of double and single stranded synthesis. Comparative analysis of Rep protein sequences from these plasmids indicates that they are highly divergent. Those isolated from Gram positive species fall into five groups: a Bacillus group, a Lactobacillus group, a Streptococcus group and two Staphylococcus aureus groups. The two S. aureus clusters are quite separate, suggesting that there has been at least one plasmid transfer between divergent Gram positive species. The double stranded origin of replication and the active site of the Rep protein display similarities across species indicating that these motifs can function in very divergent hosts. In contrast the single stranded origin of replication is typical of the host from which the plasmid is isolated. This is exemplified by (i) pKYM where the single stranded origins are similar to the minus origins found on the single-stranded coliphages, and (ii) pTD1 (isolated from a Spirochaete), pNostoc, pMA1 and pRF1 (all isolated from Cyanobacteria) which have no sequence homology to the minus origins identified in Gram positive or Gram negative species. This points to the single stranded origin as a feature critical to the determination of the host range of the plasmid.
The Kennedy Experiment

The patter of events between June 10 and November 22,1963, provided a partial test of a theory of international relations. The essence of the theory is that psychological gestures initiated by one nation will be reciprocated by others with the effect of reducing international tensions. This tension reduction, in turn, will lessen the probability of international conflicts and wars. Examining this theory in light of the 1963 experiment, I ask: (a) What are the main propositions of the theory? (b) What initiatives were actually taken by the United States in the experiment period, and how did the Union of Soviet Socialist Republics react? (c) What were the effects of these initiatives and responses on inter-bloc relations, and to what degree did these effects conform to the expectations of the theory? (d) What other factors, not accounted for by the theory, could have produced all or part of these effects? (e) What factors limited both the scope and the extent of the experiment, and under what conditions could it be replicated or extended?
Comparison of smoking habits between patients with surgically confirmed herniated lumbar and cervical disc disease and controls.

There have been numerous studies that implicate cigarette smoking as a risk factor for the development of back pain or disc disease. The purpose of this article is to review patients who underwent surgery for cervical or lumbar radiculopathy and to investigate the relationship between cigarette smoking and development of surgical disc disease. A cigarette smoking study of 205 surgical patients with lumbar and cervical disc diseases was done, with the surgical patients compared to 205 age-sex-matched inpatient controls during 1987-1988. This study was conducted at the Pennsylvania Hospital in Philadelphia, Pennsylvania. There were 163 patients with lumbar disc disease and 42 patients with cervical disc disease. The ratio of men to women was 1.5:1 for lumbar disc and 2.5:1 for cervical disc disease. Smoking history (current and ex-smokers) was strikingly increased in both prolapsed lumbar intervertebral disc (56% vs. 37% of controls, p = 0.00029) and cervical disc disease (64.3% vs. 37% of controls, p = 0.0025). Calculated relative risks for smokers were 2.2 for lumbar disc and 2.9 for cervical disc diseases. This association between cigarette smoking and disc disease was more significant when comparing between current smokers versus nonsmokers (p = 0.000011 for lumbar disc disease, and p = 0.00064 for cervical disc disease). Relative risks for current smokers were 3.0 for lumbar disc and 3.9 for cervical disc diseases. This correlation was significant for both males (p = 0.000068 for lumbar disc disease, p = 0.043 for cervical disc disease) and females (p = 0.018 for lumbar disc disease, p = 0.006 for cervical disc disease). (ABSTRACT TRUNCATED AT 250 WORDS)
Comparing grounded theory and phenomenology as methods to understand lived experience of engineering educators implementing problem-based learning

ABSTRACT Convincing teachers to implement pedagogical innovations is notoriously hard. This research project investigated the shift in pedagogical approach among a small group of faculty as they replaced traditional lecture-based methods with problem-based learning projects. Interviews were conducted with eight drivers of this change, around the question: What was it like to be part of a learning group focused on tangible change toward student-centred learning? Objectives were to understand how pedagogical change happened in an electrical engineering programme at a post-secondary institution in Ireland; analyse data using two different research methods; describe the processes, results, and findings, determining: To what extents do the research methods of grounded theory and phenomenology fit our data and yield relevant and useful findings? Results of this multiple-methods approach indicate enjoyment, camaraderie, and grassroots ownership were essential to driving transformation. With this specific dataset, grounded theory produced valuable findings (including a graphic model of change). Phenomenological methodologies seeking to understanding raw, pre-reflective experience were not as effective, because interviews occurred two years after the events and thus interview comments were inherently reflective. This report should be of particular use to teachers and administrators strategising change and engineering education researchers assessing the applicability of various methods.
Online Consumer Surveys as a Methodology for Assessing the Quality of the United States Health Care System

Background Interest in monitoring the quality of health care in the United States has increased in recent years. However, the policy objectives associated with collecting this information are constrained by the limited availability of timely and relevant data at a reasonable cost. Online data-collection technologies hold the promise of gathering data directly and inexpensively from large, representative samples of patients and consumers. These new information technologies also permit efficient, real-time assessment in such areas as health status, access to care, and other aspects of the care experience that impact health outcomes. Objective This study investigates the feasibility, validity, and generalizability of consumer online surveys to measure key aspects of health care quality in the United States. Methods Surveys about the health and health care experiences of a general adult population and of adults with diabetes were administered online and by telephone. The online survey drew from a sample frame of nearly 1 million consumers and used a single e-mail notification. The random-digit-dial methodology included 6 follow-up calls. Results from the online sample were compared to the telephone sample and to national benchmark data. Results Survey responses about quality of care collected using online and telephone methods were commensurate once they were weighted to represent the demographic distribution of the 2000 United States Census. Expected variations in health and health care quality across demographic and socioeconomic groups were largely observed, as were hypothesized associations among quality indicators and other variables. Fewer individuals were required to be contacted to achieve target sample sizes using online versus telephone methods. Neither method yielded representative cohorts of nonwhite individuals. Conclusions Conclusions about the level and variations in health care quality in the United States are similar using data collected in this study compared to data collected using other telephone-based survey methods. As is typical for national telephone surveys conducted by the National Center for Health Statistics, stratified sampling and weighting of survey responses is necessary for results to be generalizable. Online methods are more appropriate for understanding health care quality than for conducting epidemiologic assessments of health in the United States.
Immediate Response of Mammalian Target of Rapamycin (mTOR)‐Mediated Signalling Following Acute Resistance Exercise in Rat Skeletal Muscle

The purpose of the present investigation was to determine whether mammalian target of rapamycin (mTOR)‐mediated signalling and some key regulatory proteins of translation initiation are altered in skeletal muscle during the immediate phase of recovery following acute resistance exercise. Rats were operantly conditioned to reach an illuminated bar located high on a Plexiglass cage, such that the animals completed concentric and eccentric contractions involving the hindlimb musculature. Gastrocnemius muscle was extracted immediately after acute exercise and 5, 10, 15, 30 and 60 min of recovery. Phosphorylation of protein kinase B (PKB) on Ser‐473 peaked at 10 min of recovery (282 % of control, P < 0.05) with no significant changes noted for mTOR phosphorylation on Ser‐2448. Eukaryotic initiation factor (eIF) 4E‐binding protein‐1 (4E‐BP1) and S6 kinase‐1 (S6K1), both downstream effectors of mTOR, were altered during recovery as well. 4E‐BP1 phosphorylation was significantly elevated at 10 min (292 %, P < 0.01) of recovery. S6K1 phosphorylation on Thr‐389 demonstrated a trend for peak activation at 10 min following exercise (336 %, P= 0.06) with ribosomal protein S6 phosphorylation being maximally activated at 15 min of recovery (647 %, P < 0.05). Components of the eIF4F complex were enhanced during recovery as eIF4E association with eIF4G peaked at 10 min (292 %, P < 0.05). Events regulating the binding of initiator methionyl‐tRNA to the 40S ribosomal subunit were assessed through eIF2B activity and eIF2α phosphorylation on Ser‐51. No differences were noted with either eIF2B or eIF2α. Collectively, these results provide strong evidence that mTOR‐mediating signalling is transiently upregulated during the immediate period following resistance exercise and this response may constitute the most proximal growth response of the cell.
Outcome of Screening for Hepatitis C Virus Infection Based on Risk Factors

OBJECTIVES:Screening for hepatitis C virus (HCV) infection in individuals at increased risk is currently recommended by most, but not all, health authorities. This study identifies outcomes of individuals diagnosed through a screening program targeting high-risk patients.METHODS:Veterans presenting for care in VA facilities are assessed for HCV risk factors by a questionnaire. Those with a risk factor are offered anti-HCV testing. Between October 1998 and May 2004, 25,701 patients were assessed and 8,471 patients had a risk factor for HCV. Patients diagnosed through the screening program were assessed per study protocol.RESULTS:The prevalence of a positive HCV antibody in veterans who identified a risk factor was 7.3% (95% CI 6.6–8.0%). Among those diagnosed through the screening program (N = 260), 47% had chronic hepatitis C. Among patients with chronic HCV, 18% had evidence of advanced liver disease (stage III/IV on biopsy or clinical cirrhosis) while 34% had persistently normal alanine aminotransferase (ALT). Two-thirds of individuals who underwent liver biopsy had minimal or no fibrosis. About half (47%) of the screen-detected patients with chronic HCV were treatment candidates. Forty-four percent were not immediate candidates secondary to medical or psychiatric comorbidities or active substance abuse. Twenty-two patients (8%) had died after a median follow-up of 911 days. Two were liver-related deaths.CONCLUSION:Screening for hepatitis C in persons at high risk can lead to early identification of individuals at risk for progressive liver disease who may benefit from antiviral therapy and counseling to reduce HCV-related liver injury.
Importance of the lay press in the transmission of medical knowledge to the scientific community.

BACKGROUND Efficient, undistorted communication of the results of medical research is important to physicians, the scientific community, and the public. Information that first appears in the scientific literature is frequently retransmitted in the popular press. Does popular coverage of medical research in turn amplify the effects of that research on the scientific community? METHODS To test the hypothesis that researchers are more likely to cite papers that have been publicized in the popular press, we compared the number of references in the Science Citation Index to articles in the New England Journal of Medicine that were covered by The New York Times with the number of references to similar articles that were not covered by the Times. We also performed the comparison during a three-month period when the Times was on strike but continued to prepare an "edition of record" that was not distributed; doing so enabled us to address the possibility that coverage in the Times was simply a marker of the most important articles, which would therefore be cited more frequently, even without coverage in the popular press. RESULTS Articles in the Journal that were covered by the Times received a disproportionate number of scientific citations in each of the 10 years after the Journal articles appeared. The effect was strongest in the first year after publication, when Journal articles publicized by the Times received 72.8 percent more scientific citations than control articles. This effect was not present for articles published during the strike; articles covered by the Times during this period were no more likely to be cited than those not covered. CONCLUSIONS Coverage of medical research in the popular press amplifies the transmission of medical information from the scientific literature to the research community.
Sequence-Based Identification of Aerobic Actinomycetes

ABSTRACT We investigated the utility of 500-bp 16S rRNA gene sequencing for identifying clinically significant species of aerobic actinomycetes. A total of 28 reference strains and 71 clinical isolates that included members of the genera Streptomyces, Gordonia, and Tsukamurella and 10 taxa of Nocardia were studied. Methods of nonsequencing analyses included growth and biochemical analysis, PCR-restriction enzyme analysis of the 439-bp Telenti fragment of the 65 hsp gene, susceptibility testing, and, for selected isolates, high-performance liquid chromatography. Many of the isolates were included in prior taxonomic studies. Sequencing of Nocardia species revealed that members of the group were generally most closely related to the American Type Culture Collection (ATCC) type strains. However, the sequences of Nocardia transvalensis, N. otitidiscaviarum, and N. nova isolates were highly variable; and it is likely that each of these species contains multiple species. We propose that these three species be designated complexes until they are more taxonomically defined. The sequences of several taxa did not match any recognized species. Among other aerobic actinomycetes, each group most closely resembled the associated reference strain, but with some divergence. The study demonstrates the ability of partial 16S rRNA gene sequencing to identify members of the aerobic actinomycetes, but the study also shows that a high degree of sequence divergence exists within many species and that many taxa within the Nocardia spp. are unnamed at present. A major unresolved issue is the type strain of N. asteroides, as the present one (ATCC 19247), chosen before the availability of molecular analysis, does not represent any of the common taxa associated with clinical nocardiosis.
The development and characterization of a thermosiphon photobioreactor for the cultivation of photosynthetic bacteria

v ABSTRAK . vii TABLE OF CONTENTS . ix LIST OF FIGURES . xii LIST OF TABLES . xvi NOMENCLATURE . xvii CHAPTER ONE: INTRODUCTION . 1 1.1 BACKGROUND AND MOTIVATION . 1 1.2 RESEARCH OBJECTIVES AND QUESTIONS . 4 1.2.1 OBJECTIVES . 4 1.2.2 RESEARCH QUESTIONS . 5 1.3 THESIS OVERVIEW . 5 CHAPTER TWO: LITERATURE REVIEW . 7 2.1 PHOTOFERMENTATION BY PURPLE NON-SULPUR BACTERIA . 7 2.2 PHOTOBIOREACTORS: DESIGNS AND TYPES . 10 2.2.1 VERTICAL COLUMN PBR. 12 2.2.2 FLAT PLATE PBR . 13 2.2.3 TUBULAR PBR . 14 2.3 LIGHT AVAILABILITY, TRANSMISSION AND SIMULATION . 16 Stellenbosch University https://scholar.sun.ac.za