A Guide to Disability Statistics from the National Health Interview Survey

The purpose of this paper is to examine the information on the population with disabilities in a nationally representative survey conducted by the National Center on Health Statistics called the National Health Interview Survey (NHIS). The paper provides a description of the disability information available in the NHIS and how the data may be used to assess the employment, economic well being and health of the population. Descriptive statistics from the 2002 NHIS public use files are used to illustrate the type of analysis that will be useful to researchers and policymakers

Minimum requirements for feedback enhanced force sensing

The problem of estimating an unknown force driving a linear oscillator is revisited. When using linear measurement, feedback is often cited as a mechanism to enhance bandwidth or sensitivity. We show that as long as the oscillator dynamics are known, there exists a real-time estimation strategy that reproduces the same measurement record as any arbitrary feedback protocol. Consequently some form of nonlinearity is required to gain any advantage beyond estimation alone. This result holds true in both quantum and classical systems, with non-stationary forces and feedback, and in the general case of non-Gaussian and correlated noise. Recently, feedback enhanced incoherent force sensing has been demonstrated [Nat. Nano. \textbf{7}, 509 (2012)], with the enhancement attributed to a feedback induced modification of the mechanical susceptibility. As a proof-of-principle we experimentally reproduce this result through straightforward filtering.Comment: 5 pages + 2 pages of Supplementary Informatio

Cambrian Hydrocarbon Potential Indicated in Kentucky\u27s Rome Trough

A recent gas discovery in the Rome Trough has resulted in a new phase of deep exploration in eastern Kentucky. This activity is located in Elliott County, near the northern boundary fault of the Cambrian Rome Trough graben. The Carson Associates No. 1 Kazee well was drilled in 1994, and blew out with a reported uncontrolled flow of 11 million cubic feet of gas per day. Although completed at a much lower rate, this well renewed interest in the deep gas potential of the Rome Trough, which has seen sporadic drilling activity since the 1940\u27s. Gas production in the Rome Trough is from marine sandstones and fractured shales assigned to the Cambrian Rome Formation or Conasauga Group. These units are significantly thicker in the fault-bounded extensional graben that trends west-southwest to northeast in eastern Kentucky and continues through West Virginia and Pennsylvania into New York. Recent mapping of the Precambrian basement surface has refined the structure of eastern Kentucky and the Rome Trough. Reservoir fades include fine- to very fine-grained, micaceous, and glauconitic sandstones and fractured shales. Coarser sandstones may occur near border faults, in fan-delta deposits. Traps are primarily structural, and faulting was contemporaneous with deposition. Stratigraphic traps may also exist in the trough, but have not been proven by drilling to date. Stratigraphic traps may include sandstones deposited in turbidite fans in deeper parts of the graben. Potential hydrocarbon source rocks have not been identified. Limited geochemical analyses of well and outcrop samples from the Rome and Conasauga intervals show poor hydrocarbon source potential. Composition of gas produced from the Rome Trough varies significantly in eastern Kentucky. Several occurrences of gas high in nitrogen and helium content were found in the western part of the trough, and may be related to proximity to the Grenville Front. Gas of commercial quality is typical in the eastern part of the trough, where several wells are producing gas with Btu values over 1,000. Significant hydrocarbon potential remains in the Rome Trough, but this play is characterized by complex faulting that influenced the deposition and distribution of potential reservoir rocks. Interpretation of high-quality seismic data will be a key factor to future success in this play

Structure and Isopach Maps of the Mississippian Big Lime (Newman Limestone/Slade Formation), Eastern Kentucky

The maps included in this publication were made using stratigraphic data collected by us from almost 8,000 wells as part of a regional stratigraphic study of the Mississippian Slade Formation in eastern Kentucky. The data extend from the Mississippian outcrop belt along the northwestern edge of the map area to the state borders on the northeast. The southeastern border of the map area is marked by the Pine Mountain Fault. Formation tops data for these wells were collected from geophysical (electric) logs and drillers\u27 logs, and are available in electronic format from the Kentucky Geological Survey (Harris and Sparks, 1997). In the subsurface this stratigraphic interval is commonly referred to as the Big Lime by drillers. Because this term is widely used in the oil and gas industry, it will be used in this publication. Regional geologic cross sections for the mapped area by Harris and Sparks (2000) were previously published. These structural and stratigraphic cross sections were constructed from geophysical well logs and provide additional data (lithology, porosity) for the Big Lime. These structure and isopach maps illustrate the structural configuration and thickness, respectively, of the Mississippian Slade Formation (Newman Limestone or Big Lime). Data points used to make the maps are shown. The maps include both color shading and labeled contours. The structure map is contoured with a 50-ft interval, and the isopach with a 15-ft interval

Structural Evolution and Petroleum Potential of a Cambrian Intracratonic Rift System: Mississippi Valley Graben, Rough Creek Graben, and Rome Trough

Drilling and geophysical data demonstrate that the Mississippi Valley Graben, Rough Creek Graben, and Rome Trough are fault-bounded structures filled with as much as 27,000 ft of Cambrian sediments. Data including stratigraphic tops from 1,764 wells, 106 seismic profiles, aeromagnetic and gravity surveys, and mapped surface geology at a scale of 1:24,000 were used to study seven stratigraphic packages across parts of Kentucky, Ohio, Indiana, Illinois, Missouri, and Tennessee. Detailed analysis of the thickness patterns of these stratigraphic packages was used to interpret the locations and timing of movement along major fault systems in the study area. Active rifting of the Precambrian crystalline bedrock began by the Early Cambrian and resulted in thick, sand-rich deposits of the Reelfoot Arkose in the Mississippi Valley Graben and Rough Creek Graben, and the Rome Formation in the Rome Trough. Subsidence continued in these grabens during the Middle to Late Cambrian, leading to deposition of an alternating succession of shales and carbonates (Eau Claire Formation of the Illinois Basin and Conasauga Group of the Appalachian Basin) on top of the coarse clastic Reelfoot Arkose and Rome Formation. Although the tectonic extension that formed these features ended by the Late Cambrian, fault-zone reactivation during the Taconic, Acadian, and Alleghenian Orogenies altered fault-block orientations and produced areas of basin inversion, possibly creating numerous deep structural traps for hydrocarbons sourced by the Cambrian shales of the Eau Claire Formation and Conasauga Group