Dynamical shift condition for unequal mass black hole binaries

Certain numerical frameworks used for the evolution of binary black holes make use of a gamma driver, which includes a damping factor. Such simulations typically use a constant value for damping. However, it has been found that very specific values of the damping factor are needed for the calculation of unequal mass binaries. We examine carefully the role this damping plays, and provide two explicit, non-constant forms for the damping to be used with mass-ratios further from one. Our analysis of the resultant waveforms compares well against the constant damping case.Comment: 10 pages, 14 figure

328— Watershed Analysis of the Eberswalde Delta (Early Hesperian), Mars

The Eberswalde Delta is an impressive Martian fluvial-deltaic system. It is fed by an Earth-like dendritic river system that indicates past precipitation. This study is designed to quantify controls on network morphometry and its past extent using Esri ArcMap. Upstream contributing area (km2), elevation (m), depth (m), width (m), W/D ratio, and slope (-m/m), were calculated and graphed by stream order and long profiles. Width/depth increased with distance downstream but fluctuated in the fifth-order channel that was convex with knickpoints. This implied the system was youthful. The fourth-order stream was concave and in a sedimentary sub-basin. This sub-basin may have been an Early Hesperian lake with water elevation fluctuations; this could have generated knicks/youthful convex profiles of the first to third-order streams. Width and depth correlated weakly to slope which suggested additional lithologic control from the heterogenous ejecta of Holden Crater. A degradation of ~35 m was calculated from the age of Eberswalde and basaltic plain degradation rates (Mangold et al., 2012; Sweeney et al., 2018). Many first-order streams were near drainage divides with minimal upstream contributing area. This suggested degradation less than 35 m and that the system was not much more complex than present

Inflation and seigniorage studies in Africa

The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file (viewed on April 2, 2008)Includes bibliographical references.Thesis (M.A.) University of Missouri-Columbia 2007.Dissertations, Academic -- University of Missouri--Columbia -- Economics.This paper explores the link between inflation and seigniorage, which is the revenue governments get from printing money. My research uses data from twenty-nine African countries in the time period 1981 to 2005 to find the inflation and seigniorage connection in long-term, short-term, and country-by-country analysis. The inflation-seigniorage link should be in the form of a Laffer curve and my results confirm this hypothesis. The inflation-seigniorage link is a significant problem in monetary economics as it relates to maximizing government revenues from the printing of money and the possibility of hyperinflation from the excessive pursuit of seigniorage. My research implies that seigniorage comes from the inflation tax alone (as the form of the Laffer curve without an intercept is a great deal more significant than the version with an intercept) and that countries rarely attempt to maximize seigniorage, as demonstrated by the rarity of inflation figures past the peak of the Laffer curve

Blockchain Research in Information Systems: Current Trends and an Inclusive Future Research Agenda

The potential of blockchain has been extensively discussed in practitioner literature, yet rigorous empirical and theory-driven information systems (IS) research on blockchain remains scarce. This special issue addresses the need for innovative research that offers a fresh look at the opportunities and challenges of blockchain. This editorial integrates and goes beyond the papers included in this special issue by providing a framework for blockchain research in IS that emphasizes two important issues. First, we direct the attention of IS research toward the blockchain protocol level, which is characterized by recursive interactions between human agents and the blockchain protocol. Second, we highlight the need for IS research to consider how the protocol level constrains and affords blockchain applications, and how these constraints and other concerns at the application level lead to changes at the protocol level. Rooted in a socio-material view of IS, we offer a multi-paradigmatic IS research agenda that underscores the need for behavioral (individual, group, and organizational), design science, and IS economics research on blockchain. Our research agenda emphasizes issues of blockchain governance, human and material agency, blockchain affordances and constraints, as well as the consequences of its use

A practical model of twin-beam experiments for sub-shot-noise absorption measurements

Quantum-intensity-correlated twin beams of light can be used to measure absorption with precision beyond the classical shot-noise limit. The degree to which this can be achieved with a given estimator is defined by the quality of the twin-beam intensity correlations, which is quantified by the noise reduction factor. We derive an analytical model of twin-beam experiments, incorporating experimental parameters such as the relative detection efficiency of the beams, uncorrelated optical noise, and uncorrelated detector noise. We show that for twin beams without excessive noise, measured correlations can be improved by increasing the detection efficiency of each beam, notwithstanding this may unbalance detection efficiency. However, for beams with excess intensity or other experimental noise, one should balance detection efficiency, even at the cost of reducing detection efficiency -- we specifically define these noise conditions and verify our results with statistical simulation. This has application in design and optimization of absorption spectroscopy and imaging experiments.Comment: 4 page main text, 4 page appendix, 4 figure

Clark County town advisory boards and citizens advisory councils: Participation rates

Citizen participation rates in Clark County Town Advisory Boards (TABs) and Citizens Advisory Councils (CACs) were assessed. We measured citizen participation by analyzing attendance at TAB and CAC meetings over a two-month period. We designed a survey and distributed it to TAB and CAC meetings to profile volume of attendees, demographic characteristics, and other relevant data. Each member of our group also personally attended two TAB and CAC meetings to collect observations and conducted an interview with the Clark County liaison for that group. We also examined the Clark County website to determine if it could be better used to enhance citizen participation. Our results show that a substantial portion of the demographic in Clark County, including minorities and young adults, is not represented at TAB and CAC meetings. We also find that communication between citizens and government at TAB and CAC meetings can be further enhanced and optimized. We found the Clark County website somewhat difficult to navigate overall, which could impede citizens’ electronic participation capabilities. We recommend that Clark County consider initiatives to reach out to minorities, take measures to enhance two-way communication between citizens and government at TAB and CAC meetings, and solicit and incorporate citizen feedback as they move forward with the restructuring and revamping of their current website

Within- and among-population variation in oviposition preference for urea-supplemented food in Drosophila melanogaster

Oviposition preference for ureasupplemented food was assayed by simultaneous choice trials on five pairs of closely related laboratory populations of Drosophila melanogaster.Each pair of populations had been derived from a separate ancestral population about 85 generations prior to this study. One population in each pair had been subjected to selection for larval tolerance to the toxic effects of urea; the other population served as a control. Considerable variation in oviposition preference was seen both within and among populations, with four of the ten populations showing a significant mean preference for ureasupplemented food. The degree of specificity shown by individual females was surprisingly high, leading to a bimodal distribution of oviposition preference in some populations. Overall, selection for larval tolerance to urea did not significantly affect oviposition preference. However, the data indicated that pairwise comparisons between randomly selected populations from the two larval selection regimes would lead to a range of possible outcomes, suggesting, in several cases, that selection for larval urea tolerance had led to significant differentiation of adult oviposition preference for urea in one or the other direction. The results, therefore, highlight the importance of population level replication and caution against the practice, common in ecological studies, of assaying oviposition preference in two populations that utilize different hosts in nature, and then drawing broad evolutionary inferences from the results