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Search Results: 1 - 10 of 727 matches for " Katie Coughlin "
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Using the QBO to predict the number of hurricanes hitting the U.S
Katie Coughlin
Physics , 2007,
Abstract: A simple study of the relationship between the QBO and the number of hurricanes in the Atlantic, both in the Basin and hitting the U.S. coastline, demonstrates that the QBO is not a particularly useful index to help predict hurricane numbers on five-year time scales. It is shown that there is very little difference between the number of hurricanes following easterly winds in the equatorial stratosphere and the number that follow westerly winds. Given this it is reasonable one would make better predictions just using the mean number of hurricanes in lieu of using the QBO and this is also simply demonstrated here.
Ethical issues in epidemiologic research and public health practice
Steven S Coughlin
Emerging Themes in Epidemiology , 2006, DOI: 10.1186/1742-7622-3-16
Abstract: A rich and growing body of literature has emerged on ethics in epidemiologic research and public health practice [1-11]. Recent articles have included conceptual frameworks of public health ethics and overviews of historical developments in the field [7,8,11]. Several important topics in public health ethics have also been highlighted [7,11,12].This article provides an overview of ethical issues in epidemiologic research and public health practice for readers who do not necessarily have an in-depth knowledge of public health ethics. In the discussion that follows, a summary is provided of current definitions and conceptualizations of public health ethics and key ethical concerns in the field.The starting point for conceptualizations of public health ethics has often been general definitions of public health, such as the definition provided by the Institute of Medicine in 1988: "Public health is what we, as a society, do collectively to assure the conditions in which people can be healthy." As noted by Childress et al. [8], "Public health is primarily concerned with the health of the entire population, rather than the health of individuals. Its features include an emphasis on the promotion of health and the prevention of disease and disability; the collection and use of epidemiological data, population surveillance, and other forms of empirical quantitative assessment; a recognition of the multidimensional nature of the determinants of health; and a focus on the complex interactions of many factors – biological, behavioral, social, and environmental – in developing effective interventions." Public health activities also include community collaborations and partnerships for health and the identification of priorities for public health action.Previous authors have identified ethical issues and core values in public health, and highlighted differences and similarities between public health ethics and other areas of bioethics [5,7]. Public health ethics, which can be def
How Many Principles for Public Health Ethics?
Steven S. Coughlin
The Open Public Health Journal , 2008, DOI: 10.2174/1874944500801010008]
Abstract: General moral (ethical) principles play a prominent role in certain methods of moral reasoning and ethical decision- making in bioethics and public health. Examples include the principles of respect for autonomy, beneficence, nonmaleficence, and justice. Some accounts of ethics in public health have pointed to additional principles related to social and environmental concerns, such as the precautionary principle and principles of solidarity or social cohesion. This article provides an overview of principle-based methods of moral reasoning as they apply to public health ethics including a summary of advantages and disadvantages of methods of moral reasoning that rely upon general principles of moral reasoning. Drawing upon the literature on public health ethics, examples are provided of additional principles, obligations, and rules that may be useful for analyzing complex ethical issues in public health. A framework is outlined that takes into consideration the interplay of ethical principles and rules at individual, community, national, and global levels. Concepts such as the precautionary principle and solidarity are shown to be useful to public health ethics to the extent that they can be shown to provide worthwhile guidance and information above and beyond principles of beneficence, nonmaleficence, and justice, and the clusters of rules and maxims that are linked to these moral principles. Future directions likely to be productive include further work on areas of public health ethics such as public trust, community empowerment, the rights of individuals who are targeted (or not targeted) by public health interventions, individual and community resilience and wellbeing, and further clarification of principles, obligations, and rules in public health disciplines such as environmental science, prevention and control of chronic and infectious diseases, genomics, and global health.
Editorial - How Health Services Researchers are Helping to Transform the Delivery of Medical Care in the United States
Steven S. Coughlin
The Open Health Services and Policy Journal , 2008, DOI: 10.2174/1874924000801010001]
Abstract: 1-4
Observations and Models of Eclipsing Binary Systems: RT And, TU Boo, KV Gem, UU Lyn, MY Cyg, KR Per, RU Eri, and YY Cet
Jeffrey L. Coughlin
Physics , 2010,
Abstract: Eclipsing binary systems form the fundamental basis of Astronomy in the sense that they are the primary means to determine fundamental stellar astrophysical quantities such as mass, radius, and temperature. Furthermore, they allow us to study the internal dynamos and resulting magnetic cycles of stars that we would normally only be able to study for one star, our Sun. The systems themselves are extremely interesting objects, consisting of a multitude of configurations that are tied together by a complex evolutionary history. Finally, they allow us to test theories of stellar structure and even General Relativity. Thus the accurate observation and modeling of these systems is of great importance to the field. The first three chapters of this thesis are devoted to acquainting a reader with a general science background, but no knowledge of Astronomy, to eclipsing binaries and the field in general, and should provide the reader with an adequate background to understand the rest of the thesis. The subsequent eight chapters are each devoted to the analysis of eight separate systems, (RT And, TU Boo, KV Gem, UU Lyn, MY Cyg, KR Per, RU Eri, and YY Cet), with each chapter arranged as would be generally found in a journal article. The collected data, models, and derived parameters for each system are analyzed in context to previous findings and general trends seen throughout the thesis. An evolutionary scenario for the formation of A and W type W Uma systems, with two types of near-contact systems as precursors and intermediates, is proposed.
Seismic topographic scattering in the context of GW detector site selection
Michael Coughlin,Jan Harms
Physics , 2011, DOI: 10.1088/0264-9381/29/7/075004
Abstract: In this paper, we present a calculation of seismic scattering from irregular surface topography in the Born approximation. Based on US-wide topographic data, we investigate topographic scattering at specific sites to demonstrate its impact on Newtonian-noise estimation and subtraction for future gravitational-wave detectors. We find that topographic scattering at a comparatively flat site in Oregon would not pose any problems, whereas scattering at a second site in Montana leads to significant broadening of wave amplitudes in wavenumber space that would make Newtonian-noise subtraction very challenging. Therefore, it is shown that topographic scattering should be included as criterion in the site-selection process of future low-frequency gravitational-wave detectors.
Upper Limit on a Stochastic Background of Gravitational Waves from Seismic Measurements in the Range 0.05 Hz to 1 Hz
Michael Coughlin,Jan Harms
Physics , 2014, DOI: 10.1103/PhysRevLett.112.101102
Abstract: In this paper, we present an upper limit of $\Omega_{\rm GW}<1.2\times 10^{8}$ on an isotropic stochastic gravitational-wave (GW) background integrated over a year in the frequency range 0.05 Hz - 1 Hz, which improves current upper limits from high-precision laboratory experiments by about 9 orders of magnitude. The limit is obtained using the response of Earth itself to GWs via a free-surface effect described more than 40 years ago by F.J. Dyson. The response was measured by a global network of broadband seismometers selected to maximize the sensitivity.
Seedless clustering in all-sky searches for gravitational-wave transients
Eric Thrane,Michael Coughlin
Physics , 2014, DOI: 10.1103/PhysRevD.89.063012
Abstract: The problem of searching for unmodeled gravitational-wave bursts can be thought of as a pattern recognition problem: how to find statistically significant clusters in spectrograms of strain power when the precise signal morphology is unknown. In a previous publication, we showed how "seedless clustering" can be used to dramatically improve the sensitivity of searches for long-lived gravitational-wave transients. In order to manage the computational costs, this initial analysis focused on externally triggered searches where the source location and emission time are both known to some degree of precision. In this paper, we show how the principle of seedless clustering can be extended to facilitate computationally-feasible, all-sky searches where the direction and emission time of the source are entirely unknown. We further demonstrate that it is possible to achieve a considerable reduction in computation time by using graphical processor units (GPUs), thereby facilitating more sensitive searches.
Constraining the gravitational wave energy density of the Universe in the Range 0.1 Hz to 1 Hz using the Apollo Seismic Array
Michael Coughlin,Jan Harms
Physics , 2014, DOI: 10.1103/PhysRevD.90.102001
Abstract: In this paper, we describe an analysis of Apollo era lunar seismic data that places an upper limit on an isotropic stochastic gravitational-wave background integrated over a year in the frequency range 0.1\,Hz -- 1\,Hz. We find that because the Moon's ambient noise background is much quieter than that of the Earth, significant improvements over an Earth based analysis were made. We find an upper limit of $\Omega_{\rm GW}<1.2\times 10^{5}$, which is three orders of magnitude smaller than a similar analysis of a global network of broadband seismometers on Earth and the best limits in this band to date. We also discuss the benefits of a potential Earth-Moon correlation search and compute the time-dependent overlap reduction function required for such an analysis. For this search, we find an upper limit an order of magnitude larger than the Moon-Moon search.
Fundamental Parameters of Exoplanets and Their Host Stars
Jeffrey L. Coughlin
Physics , 2013,
Abstract: For much of human history we have wondered how our solar system formed, and whether there are any other planets like ours around other stars. Only in the last 20 years have we had direct evidence for the existence of exoplanets, with the number of known exoplanets dramatically increasing in recent years, especially with the success of the Kepler mission. Observations of these systems are becoming increasingly more precise and numerous, thus allowing for detailed studies of their masses, radii, densities, temperatures, and atmospheric compositions. However, one cannot accurately study exoplanets without examining their host stars in equal detail, and understanding what assumptions must be made to calculate planetary parameters from the directly derived observational parameters. In this thesis, I present observations and models of the primary transits and secondary eclipses of transiting exoplanets from both the ground and Kepler in order to better study their physical characteristics and search for additional exoplanets. I then identify, observe, and model new eclipsing binaries to better understand the stellar mass-radius relationship and stellar limb-darkening, compare these observations to the predictions of stellar models, and attempt to define to what extent these fundamental stellar characteristics can impact derived planetary parameters. I also present novel techniques for the direct determination of exoplanet masses and stellar inclinations via multi-wavelength astrometry, the ground-based photometric observation of stars at sub-millimagnitude precision, the reduction of Kepler photometry from pixel-level data, the extraction of radial velocities from spectroscopic observations, and the automatic identification, period analysis, and modeling of eclipsing binaries and transiting planets in large datasets.
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