Salem numbers and Pisot numbers via interlacing

We present a general construction of Salem numbers via rational functions whose zeros and poles mostly lie on the unit circle and satisfy an interlacing condition. This extends and unifies earlier work. We then consider the "obvious" limit points of the set of Salem numbers produced by our theorems, and show that these are all Pisot numbers, in support of a conjecture of Boyd. We then show that all Pisot numbers arise in this way. Combining this with a theorem of Boyd, we show that all Salem numbers are produced via an interlacing construction.Comment: 21 pages, 5 figures, updated in response to reviewer comment

Oral History Interview: James Kee

This interview is one of series conducted concerning the Oral Hisotry of Appalachia. James Kee was the son of two Congressmen (John Kee and Elizabeth Kee) and was a member of Congress himself. He discussed his mother in depth, including how she helped her husband in his congressional work, and her attitudes towards oil imports in the 1950\u27s. He then discussed his childhood, education, early jobs, his role as assistant to the cleerk of the House, the workings of Congress and his attitudes towards the changes in Congress over the past forty years. He also discussed World War I and his service in the Air Force (Including a brief seciton on the atomic bombings), his employment experiences, his family, news media, politics, Ambassador Eddie Roddin, working is Uruguay and the political situation in South America, President Harry Truman and other U.S. Presidents, and his role with the Housing Authority.https://mds.marshall.edu/oral_history/1225/thumbnail.jp

Strategic transformation process: Toward purpose, people, process and power

Across the world, public and non-profit sector leaders face an extremely turbulent socio-political-economic environment. This environment creates additional risks and uncertainties for organizations and may hinder a leader’s ability to act strategically. Addressing these complex, constantly evolving conditions requires leaders to develop processes that involve the organization’s stakeholders and that create organizational conditions for self-generation, creativity, resilience and action planning. In this paper we provide an organizational-level, integrative framework for the strategic transformation of public and non-profit organizations to assist leaders who are committed to effective stewardship of their organizations. The Strategic Transformation Process involves an intense dialogue among organizational stakeholders designed to create a new vision, negotiate priorities, minimize risk, and create action plans and a commitment for change

Bilateral acute angle closure glaucoma precipitated by over the counter oral decongestant

Letter to the edito

Photocatalytic Concrete Pavements: Laboratory Investigation of NO Oxidation Rate Under Varied Environmental Conditions

Concrete pavements containing TiO2 can be used for air pollution control by oxidizing NOX under UV-bearing sunlight. This study employed a bench-scale photoreactor to estimate NO oxidation rates for varied environmental conditions. Rates correlated positively with NO inlet concentration and irradiance and negatively with relative humidity. No correlation occurred with flow rate. A decrease in slab moisture (previously unstudied) positively correlated with NO oxidation rate at 0–2% loss of saturated mass, but negatively correlated at losses greater that 2%. Although prior researchers deemed temperature insignificant, data indicated a positive correlation. Overall, rates ranged from 9.8–64 nmol∙m-2∙s-1

Bodily crises in skilled performance: Considering the need for artistic habits

Empirical evidence demonstrates that performing artists are confronted by a variety of ‘bodily crises’ (e.g., injury, attrition of habits induced by ageing) over the course of their careers (Wainwright, Williams, & Turner, 2005). Such crises may present a serious threat to the embodied subject. Unfortunately, many prominent theories of skill acquisition (e.g., Fitts & Posner, 1967) appear to evacuate the body from performance by suggesting that any form of conscious processing (i.e., paying conscious attention to one's action during motor skill execution) will disrupt habitual behaviour. As a result, few researchers have considered how performers might tackle bodily anomalies. In the current paper, we seek to address this issue by discussing a variety of the ‘crises’ that confront the performing body. We start by discussing a number of disciplinary practices that may contribute to these crises. Next, we argue that habitual movements must be open to ‘acts of creativity’ in order to maintain a productive relationship between the performing body and the environment. Then we consider what this ‘creative action’ might involve and discuss a number of approaches (e.g., mindfulness, somaesthetic awareness) that could maintain and improve one's movement proficiency. Here, our argument draws on Dewey's (1922) pragmatist philosophy and his belief that ‘intelligent habit’ was required to help people to improve their movement functioning. Finally, we consider the implications of our argument for current conceptualisations of ‘habitual’ movement and recommend that researchers explore the adaptive and flexible capacity of the performing body

NASAs EDSN Aims to Overcome the Operational Challenges of CubeSat Constellations and Demonstrate an Economical Swarm of 8 CubeSats Useful for Space Science Investigations

Operators of a constellation of CubeSats have to confront a number of daunting challenges that can be cost prohibitive, or operationally prohibitive, to missions that could otherwise be enabled by a satellite constellation. Challenges including operations complexity, intersatellite communication, intersatellite navigation, and time sharing tasks between satellites are all complicated by operating with the usual CubeSat size, power, and budget constraints. EDSN pioneers innovative solutions to these problems as they are presented on the nano-scale satellite platform

Epidemiology and Control of Legionellosis, Singapore

To determine trends and clinical and epidemiologic features of legionellosis in Singapore, we studied cases reported during 2000–2009. During this period, 238 indigenous and 33 imported cases of legionellosis were reported. Cases were reported individually and sporadically throughout each year. Although the annual incidence of indigenous cases had decreased from 0.46 cases per 100,000 population in 2003 to 0.16 cases per 100,000 in 2009, the proportion of imported cases increased correspondingly from 6.2% during 2000–2004 to 27.3% during 2005–2009 (p<0.0005). The prevalence of Legionella bacteria in cooling towers and water fountains was stable (range 12.1%–15.3%) during 2004–August 2008

A Foldable, Compact and Lightweight Solar Array Substrate with Large Deployed Wingspan for Small Spacecraft

A solar array (SA) mechanical subsystem made of thin and lightweight substrates was developed, built and tested for a small spacecraft. The SA is compactly foldable and deployable to a length of approximately five times the widthof the spacecraft. It has miniature hinges and latches, and deploys freely without dampers and synchronizing mechanisms. The solar cell interconnect harness consists ofthin, laminatedflexible circuits,and the substrates feature a syntactic foam core exposed to large temperature extremes. This developmental technology, currently at TRL 6, when completely proven out, would be viable for small satellites and would enable missions in the Express-class. The Express-class (or Express) refers to satellites in the range of 25kg to 100 kg that are positioned in the gap between 12U CubeSats and small ESPA-class spacecraft. Cornerstones of the SA development were compact packaging, deployment dynamic simulation, and hinge-latch tuning for dynamics and lock-up loads. Dynamic deployment simulations were modeled in Adams to observe the behavior of the unfolding array, to size the hinge springs and to monitor the lockup loads at the substrate to hinge interfaces. Extensive substrate mechanical and thermal tests were conducted to verify the substrate’s structural capability and dimensional stability in its operating environment. Thermal tests were carried out to observe the effect of mismatching coefficients of thermal expansion between the adhered flexible laminated interconnect circuits and the substrate. Gravity-negated wing deployment tests were performed at temperature limits and in vacuum to verify the overall design intent of the deployment. The stowed wing was vibration tested to verify its structural capabilities under launch environments, and then deployment tested again to demonstrate that the array as a mechanism was unaffected by launch loads. Mechanically, the Express SA substrate assembly has been advanced in its development and proven out as a structure and mechanism. Further development of the electrical power system is necessary, and additional testing for mechanical and thermal interactions of the solar cells with the overall SA substrate will need to be done. This SA subsystem would be an essential expansion to the Express hardware developed by The Applied Physics Laboratory (APL) for the advancement and enablement of Express-class missions