Semiconductor Surface Studies

Contains an introduction, reports on two research projects and a list of publications.Joint Services Electronics Program Contract DAAL03-92-C-000

Empirical analysis and prediction of nitrate loading and crop yield for corn–soybean rotations

Nitrate nitrogen losses through subsurface drainage and crop yield are determined by multiple climatic and management variables. The combined and interactive effects of these variables, however, are poorly understood. Our objective is to predict crop yield, nitrate concentration, drainage volume, and nitrate loss in subsurface drainage from a corn (Zea mays L.) and soybean (Glycine max (L.) Merr.) rotation as a function of rainfall amount, soybean yield for the year before the corn–soybean sequence being evaluated, N source, N rate, and timing of N application in northeastern Iowa, U.S.A. Ten years of data (1994–2003) from a long-term study near Nashua, Iowa were used to develop multivariate polynomial regression equations describing these variables. The regression equations described over 87, 85, 94, 76, and 95% of variation in soybean yield, corn yield, subsurface drainage, nitrate concentration, and nitrate loss in subsurface drainage, respectively. A two-year rotation under average soil, average climatic conditions, and 125 kg N/ha application was predicted to loose 29, 37, 36, and 30 kg N/ha in subsurface drainage for early-spring swine manure, fall-applied swine manure, early-spring UAN fertilizer, and late-spring split UAN fertilizer (urea ammonium nitrate), respectively. Predicted corn yields were 10.0 and 9.7 Mg/ha for the swine manure and UAN sources applied at 125 kg N/ha. Timing of application (i.e., fall or spring) did not significantly affect corn yield. These results confirm other research suggesting that manure application can result in less nitrate leaching than UAN (e.g., 29 vs. 36 kg N/ha), and that spring application reduces nitrate leaching compared to fall application (e.g., 29 vs. 37 kg N/ha). The regression equations improve our understanding of nitrate leaching; offer a simple method to quantify potential N losses from Midwestern corn–soybean rotations under the climate, soil, and management conditions of the Nashua field experiment; and are a step toward development of easy to use N management tools

Semiconductor Surface Studies

Contains an introduction, reports on two research projects and a list of publications.Joint Services Electronics Program Contract DAALO3-92-C-000

Cyclooxygenase-1 and -2 modulate sweating but not cutaneous vasodilation during exercise in the heat in young men

We recently reported that the nonselective cyclooxygenase (COX) inhibitor ketorolac attenuated sweating but not cutaneous vasodilation during moderate‐intensity exercise in the heat. However, the specific contributions of COX‐1 and COX‐2 to the sweating response remained to be determined. We tested the hypothesis that COX‐1 but not COX‐2 contributes to sweating with no role for either COX isoform in cutaneous vasodilation during moderate‐intensity exercise in the heat. In thirteen young males (22 ± 2 years), sweat rate and cutaneous vascular conductance were measured at three forearm skin sites that were continuously treated with (1) lactated Ringer\u27s solution (Control), (2) 150 μmmol·L−1 celecoxib, a selective COX‐2 inhibitor, or (3) 10 mmol L−1 ketorolac, a nonselective COX inhibitor. Participants first rested in a non heat stress condition (≥85 min, 25°C) followed by a further 70‐min rest period in the heat (35°C). They then performed 50 min of moderate‐intensity cycling (~55% peak oxygen uptake) followed by a 30‐min recovery period. At the end of exercise, sweat rate was lower at the 150 μmol·L−1 celecoxib (1.51 ± 0.25 mg·min−1·cm−2) and 10 mmol·L−1 ketorolac (1.30 ± 0.30 mg·min−1·cm−2) treated skin sites relative to the Control site (1.89 ± 0.27 mg·min−1·cm−2) (both P ≤ 0.05). Additionally, sweat rate at the ketorolac site was attenuated relative to the celecoxib site (P ≤ 0.05). Neither celecoxib nor ketorolac influenced cutaneous vascular conductance throughout the experiment (both P > 0.05). We showed that both COX‐1 and COX‐2 contribute to sweating but not cutaneous vasodilation during moderate‐intensity exercise in the heat in young men

Semiconductor Surface Studies

Contains an introduction and reports on two research projects.Joint Services Electronics Program Contract DAAL03-89-C-000

GLIMPSE: I. A SIRTF Legacy Project to Map the Inner Galaxy

GLIMPSE (Galactic Legacy Infrared Mid-Plane Survey Extraordinaire), a SIRTF Legacy Science Program, will be a fully sampled, confusion-limited infrared survey of the inner two-thirds of the Galactic disk with a pixel resolution of \~1.2" using the Infrared Array Camera (IRAC) at 3.6, 4.5, 5.8, and 8.0 microns. The survey will cover Galactic latitudes |b| <1 degree and longitudes |l|=10 to 65 degrees (both sides of the Galactic center). The survey area contains the outer ends of the Galactic bar, the Galactic molecular ring, and the inner spiral arms. The GLIMPSE team will process these data to produce a point source catalog, a point source data archive, and a set of mosaicked images. We summarize our observing strategy, give details of our data products, and summarize some of the principal science questions that will be addressed using GLIMPSE data. Up-to-date documentation, survey progress, and information on complementary datasets are available on the GLIMPSE web site: www.astro.wisc.edu/glimpse.Comment: Description of GLIMPSE, a SIRTF Legacy project (Aug 2003 PASP, in press). Paper with full res.color figures at http://www.astro.wisc.edu/glimpse/glimpsepubs.htm

A Catalog of Chandra X-ray Sources in the Carina Nebula

We present a catalog of ~14,000 X-ray sources observed by the ACIS instrument on the Chandra X-ray Observatory within a 1.42 square degree survey of the Great Nebula in Carina, known as the Chandra Carina Complex Project (CCCP). This study appears in a Special Issue of the ApJS devoted to the CCCP. Here, we describe the data reduction and analysis procedures performed on the X-ray observations, including calibration and cleaning of the X-ray event data, point source detection, and source extraction. The catalog appears to be complete across most of the field to an absorption-corrected total-band luminosity of ~10^{30.7} erg/s for a typical low-mass pre-main sequence star. Counterparts to the X-ray sources are identified in a variety of visual, near-infrared, and mid-infrared surveys. The X-ray and infrared source properties presented here form the basis of many CCCP studies of the young stellar populations in Carina.Comment: Accepted for the ApJS Special Issue on the Chandra Carina Complex Project (CCCP), scheduled for publication in May 2011. All 16 CCCP Special Issue papers are available at http://cochise.astro.psu.edu/Carina_public/special_issue.html through 2011 at least. 29 pages, 11 figure

Spitzer Survey of the Large Magellanic Cloud, Surveying the Agents of a Galaxy's Evolution (SAGE) I: Overview and Initial Results

We are performing a uniform and unbiased, ~7x7 degrees imaging survey of the Large Magellanic Cloud (LMC), using the IRAC and MIPS instruments on board the Spitzer Space Telescope in order to survey the agents of a galaxy's evolution (SAGE), the interstellar medium (ISM) and stars in the LMC. The detection of diffuse ISM with column densities >1.2x10^21 H cm^-2 permits detailed studies of dust processes in the ISM. SAGE's point source sensitivity enables a complete census of newly formed stars with masses >3 solar masses that will determine the current star formation rate in the LMC. SAGE's detection of evolved stars with mass loss rates >1x10^-8 solar masses per year will quantify the rate at which evolved stars inject mass into the ISM of the LMC. The observing strategy includes two epochs in 2005, separated by three months, that both mitigate instrumental artifacts and constrain source variability. The SAGE data are non-proprietary. The data processing includes IRAC and MIPS pipelines and a database for mining the point source catalogs, which will be released to the community in support of Spitzer proposal cycles 4 and 5. We present initial results on the epoch 1 data with a special focus on the N79 and N83 region. The SAGE epoch 1 point source catalog has ~4 million sources. The point source counts are highest for the IRAC 3.6 microns band and decrease dramatically towards longer wavelengths consistent with the fact that stars dominate the point source catalogs and that the dusty objects, e.g. young stellar objects and dusty evolved stars that detected at the longer wavelengths, are rare in comparison. We outline a strategy for identifying foreground MW stars, that may comprise as much as 18% of the source list, and background galaxies, that may comprise ~12% of the source list.Comment: Accepted by the Astronomical Journa