1,516 research outputs found

    Ike\u27s Letters to a Friend, 1941-1958

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    “Swede Hazlett was one of the people to whom I ‘opened up.’”—Dwight D. Eisenhower Dwight D. Eisenhower and E. E. (“Swede”) Hazlett grew up together in Abilene, Kansas, and remained close, corresponding regularly from 1941 until Hazlett’s death in 1958. The letters collected in this volume, many of them surprisingly revealing, contain Eisenhower’s views on a wide range of diplomatic, military, and political issues. Taken together they constitute a remarkable inner history of Eisenhowers public career. Robert Griffith’s introductory essay is a masterful account of the Eisenhower-Hazlett relationship and of the insights provided by their correspondence for understanding the Eisenhower years. Griffith’s substantial headnotes give additional detail and context where necessary and provide a sense of narrative continuity to the correspondence. The Eisenhower who emerges from these pages bears little resemblance to the bumbling caricature produced by journalists in the 1950s. But neither does he fit the role assigned to him by so many people today, whether liberal critics of the Cold War, conservative opponents of Democratic fiscal policy, or White House aides attempting to “Eisenhowerize” Ronald Reagan. He is, rather, a complex and multidimensional historical figure whom we must study, on his own terms, if we are to fully understand our recent past. Description Robert W. Griffith (1940–2011) was professor of history at American University. He is the author of The Politics ofFear: JosephR. McCarthy and the Senate, as well as more than two dozen articles on the Truman and Eisenhower eras. With a New Foreword by Miroslava Chávez-Garca. This Kansas Open Books title is funded by a grant from the National Endowment for the Humanities and the Andrew W. Mellon Foundation Humanities Open Book Program.https://digitalcommons.pittstate.edu/kansas_open_books/1026/thumbnail.jp

    Linear Chains of Styrene and Methyl-Styrene Molecules and their Heterojunctions on Silicon: Theory and Experiment

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    We report on the synthesis, STM imaging and theoretical studies of the structure, electronic structure and transport properties of linear chains of styrene and methyl-styrene molecules and their heterojunctions on hydrogen-terminated dimerized silicon (001) surfaces. The theory presented here accounts for the essential features of the experimental STM data including the nature of the corrugation observed along the molecular chains and the pronounced changes in the contrast between the styrene and methyl-styrene parts of the molecular chains that are observed as the applied bias is varied. The observed evolution with applied bias of the STM profiles near the ends of the molecular chains is also explained. Calculations are also presented of electron transport along styrene linear chains adsorbed on the silicon surface at energies in the vicinity of the molecular HOMO and LUMO levels. For short styrene chains this lateral transport is found to be due primarily to direct electron transmission from molecule to molecule rather than through the silicon substrate, especially in the molecular LUMO band. Differences between the calculated position-dependences of the STM current around a junction of styrene and methyl-styrene molecular chains under positive and negative tip bias are related to the nature of lateral electron transmission along the molecular chains and to the formation in the LUMO band of an electronic state localized around the heterojunction.Comment: 17 pages plus 11 figures. To appear in Physical Review

    Open-Path Fourier Transform Infrared Studies of Large-Scale Laboratory Biomass Fires

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    A series of nine large-scale, open fires was conducted in the Intermountain Fire Sciences Laboratory (IFSL) controlled-environment combustion facility. The fuels were pure pine needles or sagebrush or mixed fuels simulating forest-floor, ground fires; crown fires; broadcast burns; and slash pile burns. Mid-infrared spectra of the smoke were recorded throughout each fire by open path Fourier transform infrared (FTIR) spectroscopy at 0.12 cm−1 resolution over a 3 m cross-stack pathlength and analyzed to provide pseudocontinuous, simultaneous concentrations of up to 16 compounds. Simultaneous measurements were made of fuel mass loss, stack gas temperature, and total mass flow up the stack. The products detected are classified by the type of process that dominates in producing them. Carbon dioxide is the dominant emission of (and primarily produced by) flaming combustion, from which we also measure nitric oxide, nitrogen dioxide, sulfur dioxide, and most of the water vapor from combustion and fuel moisture. Carbon monoxide is the dominant emission formed primarily by smoldering combustion from which we also measure carbon dioxide, methane, ammonia, and ethane. A significant fraction of the total emissions is unoxidized pyrolysis products; examples are methanol, formaldehyde, acetic and formic acid, ethene (ethylene), ethyne (acetylene), and hydrogen cyanide. Relatively few previous data exist for many of these compounds and they are likely to have an important but as yet poorly understood role in plume chemistry. Large differences in emissions occur from different fire and fuel types, and the observed temporal behavior of the emissions is found to depend strongly on the fuel bed and product type

    XO-2b: a hot Jupiter with a variable host star that potentially affects its measured transit depth

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    The transiting hot Jupiter XO-2b is an ideal target for multi-object photometry and spectroscopy as it has a relatively bright (VV-mag = 11.25) K0V host star (XO-2N) and a large planet-to-star contrast ratio (Rp_{p}/Rs0.015_{s}\approx0.015). It also has a nearby (31.21") binary stellar companion (XO-2S) of nearly the same brightness (VV-mag = 11.20) and spectral type (G9V), allowing for the characterization and removal of shared systematic errors (e.g., airmass brightness variations). We have therefore conducted a multiyear (2012--2015) study of XO-2b with the University of Arizona's 61" (1.55~m) Kuiper Telescope and Mont4k CCD in the Bessel U and Harris B photometric passbands to measure its Rayleigh scattering slope to place upper limits on the pressure-dependent radius at, e.g., 10~bar. Such measurements are needed to constrain its derived molecular abundances from primary transit observations. We have also been monitoring XO-2N since the 2013--2014 winter season with Tennessee State University's Celestron-14 (0.36~m) automated imaging telescope to investigate stellar variability, which could affect XO-2b's transit depth. Our observations indicate that XO-2N is variable, potentially due to {cool star} spots, {with a peak-to-peak amplitude of 0.0049±0.00070.0049 \pm 0.0007~R-mag and a period of 29.89±0.1629.89 \pm 0.16~days for the 2013--2014 observing season and a peak-to-peak amplitude of 0.0035±0.00070.0035 \pm 0.0007~R-mag and 27.34±0.2127.34 \pm 0.21~day period for the 2014--2015 observing season. Because of} the likely influence of XO-2N's variability on the derivation of XO-2b's transit depth, we cannot bin multiple nights of data to decrease our uncertainties, preventing us from constraining its gas abundances. This study demonstrates that long-term monitoring programs of exoplanet host stars are crucial for understanding host star variability.Comment: published in ApJ, 9 pages, 11 figures, 3 tables; updated figures with more ground-based monitoring, added more citations to previous work

    Nodule heterogeneity as shown by size differences between the targeted nodule and the tumor in thyroidectomy specimen

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    BACKGROUND. Missed papillary thyroid carcinoma (PTC) diagnoses on fine-needle aspiration (FNA) can result from many causes. To the authors' knowledge, the issue of whether the detection of PTC is correlated with nodule heterogeneity has not been studied to date. METHODS. The authors identified all thyroidectomy specimens with a diagnosis of PTC that had undergone at least 1 prior FNA in the study institution between 1998 and 2003. The tumor size at the time of the resection, the ultrasound (US)-determined nodule size, and other parameters were compared between the 2 groups in which PTC was or was not diagnosed on FNA. RESULTS. Of a total of 89 specimens, 47 were diagnosed on FNA with an average tumor size of 1.7 cm and an US-determined nodule size of 2.1 cm (a difference of 0.4 cm). Forty-two specimens with a smaller average tumor size of 0.9 cm ( P <.0001) and a US-determined nodule size of 2.4 cm (a difference of 1.5 cm) were missed. The differences with regard to the US-determined nodule size and tumor size between the 2 groups were significant (0.4 cm vs 1.5 cm; P < .0001). In the missed group, 29 specimens were found to have PTC foci that measured ≤1.0 cm and 26 had a reasonable size difference (RSD; defined as a PTC size outside the range of ±50% of the US-determined nodule size) as the indicator of the mixed nature of nodules targeted for FNA, whereas in the diagnostic group, 9 foci measured ≤1.0 cm and 6 had RSD. There was no cytologic evidence with which to render a diagnosis of PTC on further review in the missed group. CONCLUSIONS. The major reason for a missed diagnosis of PTC on FNA is because of inadequate tumor sampling due to the heterogeneity of the nodule targeted for FNA. This is illustrated by the RSD noted between the targeted nodule and the actual PTC tumor focus in the resection specimen. Cancer (Cancer Cytopathol) 2008. © 2007 American Cancer Society.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58022/1/23253_ftp.pd

    Emissions from Smoldering Combustion of Biomass Measured by Open-Path Fourier Transform Infrared Spectroscopy

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    Biomass samples from a diverse range of ecosystems were burned in the Intermountain Fire Sciences Laboratory open combustion facility. Midinfrared spectra of the nascent emissions were acquired at several heights above the fires with a Fourier transform infrared spectrometer (FTIR) coupled to an open multipass cell. In this report, the results from smoldering combustion during 24 fires are presented including production of carbon dioxide, carbon monoxide, methane, ethene, ethyne, propene, formaldehyde, 2-hydroxyethanal, methanol, phenol, acetic acid, formic acid, ammonia, hydrogen cyanide, and carbonyl sulfide. These were the dominant products observed, and many have significant influence on atmospheric chemistry at the local, regional, and global scale. Included in these results are the first optical, in situ measurements of smoke composition from fires in grasses, hardwoods, and organic soils. About one half of the detected organic emissions arose from fuel pyrolysis which produces white smoke rich in oxygenated organic compounds. These compounds deserve more attention in the assessment of fire impacts on the atmosphere. The compound 2-hydroxyethanal is a significant component of the smoke, and it is reported here for the first time as a product of fires. Most of the observed alkane and ammonia production accompanied visible glowing combustion. NH3 is normally the major nitrogen-containing emission detected from smoldering combustion of biomass, but from some smoldering organic soils, HCN was dominant. Tar condensed on cool surfaces below the fires accounting for ∼1% of the biomass burned, but it was enriched in N by a factor of 6–7 over the parent material, and its possible role in postfire nutrient cycling should be further investigated

    A multimerizing transcription factor of sea urchin embryos capable of looping DNA

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    SpGCF1 is a recently cloned sea urchin transcription factor that recognizes target sites in several different sea urchin genes. We find that in gel-shift experiments this factor is able to multimerize. A quantitative simulation of the gel-shift results suggests that SpGCF1 molecules that are bound to DNA target sites may also bind to one another, thus associating several DNA probe molecules. SpGCF1 might therefore be able to loop DNA molecules bearing its target sites at distant locations. We demonstrate this prediction by electron microscopy, and using the well-characterized cis-regulatory domain of the CyIIIa cytoskeletal actin gene, we show that the loop conformations predicted from the known SpGCF1 target site locations are actually formed in vitro. We speculate that the multimerization of this factor in vivo may function to bring distant regions of extended regulatory domains into immediate proximity so that they can interact with one another

    The Tropical Forest and Fire Emissions Experiment: Overview and Airborne Fire Emission Factor Measurements

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    The Tropical Forest and Fire Emissions Experiment (TROFFEE) used laboratory measurements followed by airborne and ground based field campaigns during the 2004 Amazon dry season to quantify the emissions from pristine tropical forest and several plantations as well as the emissions, fuel consumption, and fire ecology of tropical deforestation fires. The airborne campaign used an Embraer 110B aircraft outfitted with whole air sampling in canisters, mass-calibrated nephelometry, ozone by UV absorbance, Fourier transform infrared spectroscopy (FTIR), and proton-transfer mass spectrometry (PTR-MS) to measure PM(10), O(3), CO(2), CO, NO, NO(2), HONO, HCN, NH(3), OCS, DMS, CH(4), and up to 48 non-methane organic compounds (NMOC). The Brazilian smoke/haze layers extended to 2 - 3 km altitude, which is much lower than the 5 - 6 km observed at the same latitude, time of year, and local time in Africa in 2000. Emission factors (EF) were computed for the 19 tropical deforestation fires sampled and they largely compare well to previous work. However, the TROFFEE EF are mostly based on a much larger number of samples than previously available and they also include results for significant emissions not previously reported such as: nitrous acid, acrylonitrile, pyrrole, methylvinylketone, methacrolein, crotonaldehyde, methylethylketone, methylpropanal, \u27\u27 acetol plus methylacetate,\u27\u27 furaldehydes, dimethylsulfide, and C(1)-C(4) alkyl nitrates. Thus, we recommend these EF for all tropical deforestation fires. The NMOC emissions were similar to 80% reactive, oxygenated volatile organic compounds (OVOC). Our EF for PM(10) (17.8 +/- 4 g/kg) is similar to 25% higher than previously reported for tropical forest fires and may reflect a trend towards, and sampling of, larger fires than in earlier studies. A large fraction of the total burning for 2004 likely occurred during a two-week period of very low humidity. The combined output of these fires created a massive \u27\u27 mega-plume \u27\u27 \u3e 500 km across that we sampled on 8 September. The mega-plume contained high PM(10) and 10 - 50 ppbv of many reactive species such as O(3), NH(3), NO(2), CH(3)OH, and organic acids. This is an intense and globally important chemical processing environment that is still poorly understood. The mega-plume or \u27\u27 white ocean \u27\u27 of smoke covered a large area in Brazil, Bolivia, and Paraguay for about one month. The smoke was transported \u3e 2000 km to the southeast while remaining concentrated enough to cause a 3 - 4-fold increase in aerosol loading in the S (a) over tildeo Paulo area for several days
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