"We drove the Alaska Highway": romanticizing the road north

Thesis (M.A.) University of Alaska Fairbanks, 2006The Alaska Highway is a road that still fascinates and draws people north more than sixty years after its initial construction. Beginning in 1942, literature concerning the road's hasty wartime construction and the men who worked on the highway led to the formation of Alaska Highway myths and legends and enticed Americans north after World War II. Many of these travelers wrote and published the accounts of their adventures, inspiring readers' to make an Alaska Highway journey as well. The objective of this work is to show how the Alaska Highway literature perpetuates the frontier romance of the northern road. This paper examines American frontierism and how the Alaska Highway was and is a perfect outlet for Americans to have a frontier experience. Also, the paper explores the various highway literature written since 1942, particularly the 'I drove the Alaska Highway' works that influenced many Americans to seek their own frontier adventures on the Alaska Highway.1. Introduction -- 1.1. Highways -- 1.2. The frontier thesis -- 1.3. The Alaska Highway as a Frontier -- 1.4. Highway literature -- 2. Building the road north -- 2.1. Evolution of the Alaska Highway -- 2.2. Construction of the Alaska Highway -- 3. Building the myth -- 3.1. Introduction -- 3.2. War stories -- 3.3. Conclusion -- 4. After the war, 1946-1963 -- 4.1. Introduction -- 4.2. Travel guide books -- 4.3. Highway stories -- 4.4. Conclusion -- 5. The adventure continues, 1964-1992 -- 5.1. Introduction -- 5.2. Road guides -- 5.3. Highway stories -- 5.4. Conclusion -- 6. Conclusion -- 6.1. The modern highway -- 6.2. Frontier romance and the Alaska Highway -- Bibliography

Facilitators and Barriers to Prescribing PreExposure Prophylaxis (PrEP) for the Prevention of HIV

Background: What is PrEP and who gets it? PrEP is the use of medication by individuals to prevent HIV contraction, approved in 2012 after demonstrating safety and efficacy in the iPrEx study and Partners PrEP2 trials. HIV infection risk is 92% lower in patients using PrEP. Truvada®, a combination of tenofovir and emtricitabine taken orally daily, is the only approved PrEP regimen and is intended to compliment other prevention strategies such as condoms. HIV negative-individuals at risk for exposure to HIV have been identified as men who have sex with men (MSM), IV drug users, heterosexuals who have unprotected sex with partners of unknown HIV status, and those in serodiscordant relationships. Barriers to PrEP Implementation PrEP is effective when patients adhere; however, both the medical community and some high-risk populations have been slow to adopt it as an HIV prevention strategy. Surveys have shown clinicians perceived barriers to PrEP such as adverse side effects, viral drug resistance, increased high-risk behavior, cost, and training. HIV in Vermont New diagnoses of HIV among Vermont residents has remained relatively stable over the last twenty years. Vermont CARES, a non-profit, offers free and anonymous HIV tests and in-person risk-reduction counseling. Clients are increasingly asking about PrEP as a prevention strategy, but the response from the medical community is difficult to ascertain.https://scholarworks.uvm.edu/comphp_gallery/1235/thumbnail.jp

Ultraspectral Sounding Retrieval Error Budget and Estimation

The ultraspectral infrared radiances obtained from satellite observations provide atmospheric, surface, and/or cloud information. The intent of the measurement of the thermodynamic state is the initialization of weather and climate models. Great effort has been given to retrieving and validating these atmospheric, surface, and/or cloud properties. Error Consistency Analysis Scheme (ECAS), through fast radiative transfer model (RTM) forward and inverse calculations, has been developed to estimate the error budget in terms of absolute and standard deviation of differences in both spectral radiance and retrieved geophysical parameter domains. The retrieval error is assessed through ECAS without assistance of other independent measurements such as radiosonde data. ECAS re-evaluates instrument random noise, and establishes the link between radiometric accuracy and retrieved geophysical parameter accuracy. ECAS can be applied to measurements of any ultraspectral instrument and any retrieval scheme with associated RTM. In this paper, ECAS is described and demonstration is made with the measurements of the METOP-A satellite Infrared Atmospheric Sounding Interferometer (IASI).

How Well Can Infrared Sounders Observe the Atmosphere and Surface Through Clouds?

Infrared sounders, such as the Atmospheric Infrared Sounder (AIRS), the Infrared Atmospheric Sounding Interferometer (IASI), and the Cross-track Infrared sounder (CrIS), have a cloud-impenetrable disadvantage in observing the atmosphere and surface under opaque cloudy conditions. However, recent studies indicate that hyperspectral, infrared sounders have the ability to detect cloud effective-optical and microphysical properties and to penetrate optically thin clouds in observing the atmosphere and surface to a certain degree. We have developed a retrieval scheme dealing with atmospheric conditions with cloud presence. This scheme can be used to analyze the retrieval accuracy of atmospheric and surface parameters under clear and cloudy conditions. In this paper, we present the surface emissivity results derived from IASI global measurements under both clear and cloudy conditions. The accuracy of surface emissivity derived under cloudy conditions is statistically estimated in comparison with those derived under clear sky conditions. The retrieval error caused by the clouds is shown as a function of cloud optical depth, which helps us to understand how well infrared sounders can observe the atmosphere and surface through clouds

Hyperspectrally-Resolved Surface Emissivity Derived Under Optically Thin Clouds

Surface spectral emissivity derived from current and future satellites can and will reveal critical information about the Earth s ecosystem and land surface type properties, which can be utilized as a means of long-term monitoring of global environment and climate change. Hyperspectrally-resolved surface emissivities are derived with an algorithm utilizes a combined fast radiative transfer model (RTM) with a molecular RTM and a cloud RTM accounting for both atmospheric absorption and cloud absorption/scattering. Clouds are automatically detected and cloud microphysical parameters are retrieved; and emissivity is retrieved under clear and optically thin cloud conditions. This technique separates surface emissivity from skin temperature by representing the emissivity spectrum with eigenvectors derived from a laboratory measured emissivity database; in other words, using the constraint as a means for the emissivity to vary smoothly across atmospheric absorption lines. Here we present the emissivity derived under optically thin clouds in comparison with that under clear conditions

Inter-comparison between AIRS and IASI through Retrieved Parameters

A State-of-the-art retrieval algorithm dealing with all-weather conditions has been applied to satellite/aircraft instruments retrieving cloud/surface and atmospheric conditions. High quality retrievals have been achieved from IASI data. Surface, cloud, and atmospheric structure and variation are well captured by IASI measurements and/or retrievals. The same retrieval algorithm is also applied to AIRS for retrieval inter-comparison. Both AIRS and IASI have a similar FOV size but AIRS has a higher horizontal resolution. AIRS data can be interpolated to IASI horizontal resolution for inter-comparison at the same geophysical locations, however a temporal variation between AIRS and IASI observations need to be considered. JAIVEx has employed aircraft to obtain the atmospheric variation filling the temporal gap between two satellites. First results show that both AIRS and IASI have a very similar vertical resolving power, atmospheric conditions are well captured by both instruments, and radiances are well calibrated. AIRS data shown in retrievals (e.g., surface emissivity and moisture) have a relatively higher noise level. Since the this type of retrieval is very sensitive to its radiance quality, retrieval products inter-comparison is an effective way to identify/compare their radiance quality, in terms of a combination of spectral resolution and noise level, and to assess instrument performance. Additional validation analyses are needed to provide more-definitive conclusions

Cloud and Thermodynamic Parameters Retrieved from Satellite Ultraspectral Infrared Measurements

Atmospheric-thermodynamic parameters and surface properties are basic meteorological parameters for weather forecasting. A physical geophysical parameter retrieval scheme dealing with cloudy and cloud-free radiance observed with satellite ultraspectral infrared sounders has been developed and applied to the Infrared Atmospheric Sounding Interferometer (IASI) and the Atmospheric InfraRed Sounder (AIRS). The retrieved parameters presented herein are from radiance data gathered during the Joint Airborne IASI Validation Experiment (JAIVEx). JAIVEx provided intensive aircraft observations obtained from airborne Fourier Transform Spectrometer (FTS) systems, in-situ measurements, and dedicated dropsonde and radiosonde measurements for the validation of the IASI products. Here, IASI atmospheric profile retrievals are compared with those obtained from dedicated dropsondes, radiosondes, and the airborne FTS system. The IASI examples presented here demonstrate the ability to retrieve fine-scale horizontal features with high vertical resolution from satellite ultraspectral sounder radiance spectra

Optimization by Quantum Annealing: Lessons from hard 3-SAT cases

The Path Integral Monte Carlo simulated Quantum Annealing algorithm is applied to the optimization of a large hard instance of the Random 3-SAT Problem (N=10000). The dynamical behavior of the quantum and the classical annealing are compared, showing important qualitative differences in the way of exploring the complex energy landscape of the combinatorial optimization problem. At variance with the results obtained for the Ising spin glass and for the Traveling Salesman Problem, in the present case the linear-schedule Quantum Annealing performance is definitely worse than Classical Annealing. Nevertheless, a quantum cooling protocol based on field-cycling and able to outperform standard classical simulated annealing over short time scales is introduced.Comment: 10 pages, 6 figures, submitted to PR

Noise and performance of propellers for light aircraft : final report

July 1980Project Manager: G. P. Succi ; Contributors: E.E. Larrabee, P.D. [i.e. P. B.] Dunbeck, D.H. Munro, J.A. Zimmer; Principal Investigators: K.U. Ingard, J.L. KerrebrockIncludes bibliographical references (pages 22-23)Final report. February 24, 1978 to July 31, 1980Introduction and Summary: The project "Noise and Performance of Propellers for Light Aircraft," Contract #NASl-15154 between NASA Langley and MIT, has now been completed, and the main results obtained are summarized in this report and its appendices. The primary practical objective of the study was to explore the possibility of reducing the noise from a general aviation type propeller without altering significantly its aerodynamic performance or the engine characteristics. After an extensive study of this question, involving aerodynamic and acoustic theory, design, construction and wind tunnel testing of model propellers, design and manufacturing of full scale propellers and, finally, flight tests, we are pleased to report that for one of the propellers tested an overall reduction of 4.8 dBA as measured in a flight test was achieved.The theory deals with aerodynamics and acoustics of lightly loaded propellers with subsonic tip speeds and includes studies of the effects of sweeping the blades, altering the radial load distribution, and changing the number of blades. These studies lead to new insight into the general problem of sound generation from moving bodies. Of particular value are the algorithms, which are well suited for computer coding. The wind tunnel tests involved three propellers, 1/4 scale, including a replica of a fixed pitch propeller used on a 150 HP single engine airplane. The other two propellers were designed to have the peak radial load distribution shifted inboard. The acoustic wind tunnel which was used in these tests enabled measurement not only of the radiated sound field but also the thrust and torque of the propeller. In addition, the load distribution was determined indirectly from wake surveys.Sound pressure signatures were obtained at different locations and speeds (up to a tip Mach number of 0.75) and compared with theoretical predictions in which only the shape and motion of the propeller were needed as input parameters; no empirical adjustments were made. Agreement to within a few percent was obtained throughout except in the presence of a transonic "buzz" instability which was encountered within a narrow speed range. On the basis of the theoretical analysis and its verification in the model tests, a two-bladed fixed pitch propeller was designed for a 150 HP single engine airplane. Flight tests with this propeller indicated about the same performance as the production propeller for that airplane, but the maximum sound level during a full power flyover at 1000 feet was found to be 4.8 dBA lower. A second propeller, with three blades and fixed pitch, was designed for the Ohio State University 180 HP single engine airplane.Flight tests of this propeller have not yet been made at this time.NASA Contract NAS1-1515

SAT-based Explicit LTL Reasoning

We present here a new explicit reasoning framework for linear temporal logic (LTL), which is built on top of propositional satisfiability (SAT) solving. As a proof-of-concept of this framework, we describe a new LTL satisfiability tool, Aalta\_v2.0, which is built on top of the MiniSAT SAT solver. We test the effectiveness of this approach by demonnstrating that Aalta\_v2.0 significantly outperforms all existing LTL satisfiability solvers. Furthermore, we show that the framework can be extended from propositional LTL to assertional LTL (where we allow theory atoms), by replacing MiniSAT with the Z3 SMT solver, and demonstrating that this can yield an exponential improvement in performance