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"Flood, Christopher"
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Timescale Realization with Linked Platforms for AltPNT
Recognition of the critical importance of positioning, navigation, and timing to all economic sectors is driving the development of diverse alternatives to global navigation satellite systems (GNSSs), termed AltPNT. One promising approach is to leverage the proliferation of small satellite constellations in low Earth orbit (LEO) to deliver GNSS augmentation services. The generation of one-way ranging signals suitable for AltPNT requires stable timing, accurately referenced to a common timescale such as Global Positioning System Time or Coordinated Universal Time. This paper describes a small-scale laboratory demonstration of an approach for cooperatively realizing a local timescale using low-size, weight, and power clocks distributed across multiple platforms, with no dependence on a GNSS. The demonstration is based on four interconnected software-defined radios to represent a four-satellite subset of a LEO constellation. Lab results show how each platform can generate a common timescale, with stability benefiting from all reference clocks.
Journal Article
Britain after Brexit
The national mood in Britain is sour. The general election of July 2024 had brought a change of government after fourteen years of increasingly detested Conservative rule. However, relief at ousting the Conservatives did not reflect wholehearted endorsement of a new Labour government whose parliamentary dominance owed far more to the distortions of an archaic electoral system than to genuine popularity of the party or its leadership. This article examines the sorry state of British politics in the light of ideological divisions leading to, and following, Britain’s withdrawal from the European Union in 2020.
Journal Article
Expanding legal treatment options for medical marijuana in the State of Louisiana
Background: The use of cannabis for ‘medical’ purposes has expanded throughout the USA. Despite the limited peer-reviewed medical research, medical marijuana therapy has been to treat chronic pain, stimulate appetite, treat nausea, and ameliorate muscle spasticity.Challenge: In the state of Louisiana, this potential treatment is strictly controlled. The ability of the individual patient to receive this therapy is limited since any prescribing provider had to be both licensed by the state medical board and registered with the board to prescribe medical marijuana. Medical cannabis could be used only for limited medical disorders. The ‘Medical Marijuana’ HB819 bill authorizes the recommendation of medical marijuana for additional conditions and allows any state-licensed physician to recommend/prescribe medical marijuana.Alternative options: The government may consider working with the state medical board to lessen its regulation allowing a collaborative effort to formalize protocols for safe prescribing of medical marijuana. A more liberal option would be to make it available to the consumer over the counter, while a state tracking mechanism is set in place to limit the amount purchased.Conclusions: Two stakeholders pertaining to this new legislation to focus on are the Louisiana State government and healthcare providers. This law probably has the biggest impact on healthcare providers and their relationship to patients. This legislation may allow providers to have more ‘freedom in medical marijuana treatment plans’. These benefits would be monitored using such criteria as cost, access to care, as well as patient and healthcare provider satisfaction.
Journal Article
Time Transfer Architectures for Small Satellite Platforms
Constellations of small satellites are playing an increasing role in supporting global communication, Earth observation, and positioning, navigation and timing (PNT). All of these applications require some level of accurate timing and frequency control onboard; however, the specific performance requirements differ dramatically. The research in this dissertation describes both radio frequency (RF) and optical techniques to support small satellite applications requiring timing between the nanosecond and femtosecond range. Radio frequency techniques are applied to a low size, weight, and power (SWaP) clock hardware testbed for sub-ns clock comparison between oscillators on separate software defined radio (SDR) platforms. The multi-platform configuration is used to demonstrate extensible timescale formation approaches, with an ensemble realization having frequency stability 1.5e-12 at 10,000 seconds. A second study presents development of a frequency comb-based optical system capable of sub-femtosecond time transfer and nanometer ranging, which can support future astronomical sensing missions. A free space experiment was conducted between the National Institute of Standards and Technology (NIST) and the University of Colorado Boulder to evaluate performance of a reduced SWaP system, which achieved sub-femtosecond time transfer and sub-micrometer ranging precision. Experimental results are comparable to previous NIST laboratory demonstrations, indicating only a minor degradation in precision when reducing SWaP. The research within this thesis outlines radio frequency and optical timekeeping techniques applicable to navigation from future satellite constellations and science missions using clusters of small satellites.
Dissertation
Political and Cultural Representations of Muslims
At a time of tension between some Muslim and non-Muslim countries, accompanied by frictions between Muslim and non-Muslim majorities or minorities within states, this collection centres on the often distorted perceptions underlying public debates over collective identities and cultures.
eBook
Nationalism or Nationism? Pierre-André Taguieff and the Defense of the French Republic
This article examines the political ideas of Pierre-André Taguieff, one of France’s leading republican intellectuals. Taguieff has had a distinguished academic career as a historian of ideas, philosopher, and political analyst. Author of more than twenty books, he is frequently interviewed, and widely quoted, in the media. He has written important works on topics such as racism and antiracism, antisemitism, populism, the idea of progress, the integration of ethnic minorities, and the continuing validity of the republican model of the nation-state. Thematically, his work has shown strong elements of continuity, but there has been organic development as Taguieff has brought related topics into play to elaborate or move beyond those he has examined previously. The main axis of his writing is analytical. He traces the history of political concepts and explores their contemporary variants. However, because his work also bears the stamp of his ideological commitments, Taguieff engages with current controversies and proposes remedies to the political problems that he examines, although he does this more often in terms of general principles than of specific policy proposals. The article has two parts. The first of these outlines the overall shape and intellectual style of Taguieff’s work. The second part takes a more critical approach, arguing that Taguieff’s increasingly defensive positions on a range of domestic and international issues—coupled with a tendency to take refuge in polemics against the political correctness and intellectual conformism of the age—threaten to swamp the more open, constructive, and innovative dimensions of his political thought.
Journal Article
Preparation of the cardiac patient for noncardiac surgery
Approximately 20 to 40 percent of patients at high risk of cardiac-related morbidity develop myocardial ischemia perioperatively. The preferred approach to diagnostic evaluation depends on the interactions of patient-specific risk factors, surgery-specific risk factors, and exercise capacity. Stress testing should be reserved for patients at moderate to high risk undergoing moderate- or high-risk surgery and those who have poor exercise capacity. Further cardiovascular studies should be limited to patients who are at high risk, have poor exercise tolerance, or have known poor ventricular function. Medical therapy using beta blockers, statins, and alpha agonists may be effective in high-risk patients. The evidence appears to be the strongest for beta blockers, especially in high-risk patients with proven ischemia on stress testing who are undergoing vascular surgery. Many questions remain unanswered, including the optimal role of statins and alpha agonists, whether or not these therapies are as effective in patients with subclinical coronary artery disease or left ventricular dysfunction, and the optimal timing and dosing regimens of these medications.
Journal Article
Evaluation of human fecal pollution in Mississippi coastal and creek waters using library independent markers
The objective of this study was to determine whether statistically valid correlations could be elucidated between standard indicator bacteria (enterococci and fecal coliforms) from coastal creek and marine samples and the presence of four library independent molecular markers that are human or sewage specific. Eight hundred and nineteen samples were collected between August 2007 and July 2010 to determine enterococcal and fecal coliform counts and the presence of genetic markers for sewage indicator organisms Methanobrevibacter smithii, human specific Bacteroides sp., Bacteroides thetaiotaomicron, and Fecalibacterium sp. During the course of this study environmental parameters were measured and statistically analyzed to determine if there was any correlation for the presence of any one of these organisms and the environmental variables.
Dissertation