390 research outputs found

    Ice volume distribution and implications on runoff projections in a glacierized catchment

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    A dense network of helicopter-based ground-penetrating radar (GPR) measurements was used to determine the ice-thickness distribution in the Mauvoisin region. The comprehensive set of ice-thickness measurements was combined with an ice-thickness estimation approach for an accurate determination of the bedrock. A total ice volume of 3.69 ± 0.31 km<sup>3</sup> and a maximum ice thickness of 290 m were found. The ice-thickness values were then employed as input for a combined glacio-hydrological model forced by most recent regional climate scenarios. This model provided glacier evolution and runoff projections for the period 2010–2100. Runoff projections of the measured initial ice volume distribution show an increase in annual runoff of 4% in the next two decades, followed by a persistent runoff decrease until 2100. Finally, we checked the influence of the ice-thickness distribution on runoff projections. Our analyses revealed that reliable estimates of the ice volume are essential for modelling future glacier and runoff evolution. Wrong estimations of the total ice volume might even lead to deviations of the predicted general runoff trend

    A Spectral Line Survey from 138.3 to 150.7 GHZ toward Orion-KL

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    We present the results of a spectral line survey from 138.3 to 150.7 GHz toward Orion-KL. The observations were made using the 14 m radio telescope of Taeduk Radio Astronomy Observatory. Typical system temperatures were between 500 and 700 K, with the sensitivity between 0.02−0.060.02 - 0.06 K in units of TA∗\rm T_A^*. A total of 149 line spectra are detected in this survey. Fifty lines have been previously reported, however we find 99 new detections. Among these new lines, 32 are `unidentified', while 67 are from molecular transitions with known identifications. There is no detection of H or He recombination lines. The identified spectra are from a total of 16 molecular species and their isotopic variants. In the range from 138.3 to 150.7 GHz, the strongest spectral line is the J=3-2 transition of CS molecule, followed by transitions of the H2CO\rm H_2CO, CH3OH\rm CH_3OH, CH3CN\rm CH_3CN, and SO2\rm SO_2. Spectral lines from the large organic molecules such as CH3OH\rm CH_3OH, CH3OCH3\rm CH_3OCH_3, HCOOCH3\rm HCOOCH_3, C2H5CN\rm C_2H_5CN and CH3CN\rm CH_3CN are prominent; with 80 % of the identified lines arising from transitions of these molecules. The rotational temperatures and column densities are derived using the standard rotation diagram analysis for CH3OH\rm CH_3OH (13CH3OH\rm ^{13}CH_3OH), HCOOCH3\rm HCOOCH_3, CH3CN\rm CH_3CN and SO2\rm SO_2 with 10∌270K\rm 10\sim 270 K and 0.2∌20×1015cm−2\rm 0.2\sim 20\times 10^{15} cm^{-2}. These estimates are fairly comparable to the values for the same molecule in other frequency regions by other studies.Comment: 10 figures, 2 tex files for a manuscript and tables, accepted to Ap

    Retirement Plans, Concepts and Attitudes of Farm Operators in Three Eastern South Dakota Counties

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    The central objective of this study was to obtain more comprehensive information on what provisions farmers are making for the latter years of their lives through answers to the following types of questions: Are they planning for retirement? If so, is it to be full or partial retirement? Will retirement mean moving away from their farm, reducing labor, reducing management? Will they have adequate sources of income in retirement years? What sources of income do they expect? What factors do they think will be important in their retirement adjustment? What characteristics are associated with a favorable attitude toward retirement

    High-Sensitivity Measurement of 3He-4He Isotopic Ratios for Ultracold Neutron Experiments

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    Research efforts ranging from studies of solid helium to searches for a neutron electric dipole moment require isotopically purified helium with a ratio of 3He to 4He at levels below that which can be measured using traditional mass spectroscopy techniques. We demonstrate an approach to such a measurement using accelerator mass spectroscopy, reaching the 10e-14 level of sensitivity, several orders of magnitude more sensitive than other techniques. Measurements of 3He/4He in samples relevant to the measurement of the neutron lifetime indicate the need for substantial corrections. We also argue that there is a clear path forward to sensitivity increases of at least another order of magnitude.Comment: 11 pages, 10 figure

    Pollen Processing Behavior of Heliconius Butterflies: A Derived Grooming Behavior

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    Pollen feeding behaviors Heliconius and Laparus (Lepidoptera: Nymphalidae) represent a key innovation that has shaped other life history traits of these neotropical butterflies. Although all flower visiting Lepidoptera regularly come in contact with pollen, only Heliconius and Laparus butterflies actively collect pollen with the proboscis and subsequently take up nutrients from the pollen grains. This study focused on the behavior of pollen processing and compared the movement patterns with proboscis grooming behavior in various nymphalid butterflies using video analysis. The proboscis movements of pollen processing behavior consisted of a lengthy series of repeated coiling and uncoiling movements in a loosely coiled proboscis position combined with up and down movements and the release of saliva. The proboscis-grooming behavior was triggered by contamination of the proboscis in both pollen feeding and non-pollen feeding nymphalid butterflies. Proboscis grooming movements included interrupted series of coiling and uncoiling movements, characteristic sideways movements, proboscis lifting, and occasionally full extension of the proboscis. Discharge of saliva was more pronounced in pollen feeding species than in non-pollen feeding butterfly species. We conclude that the pollen processing behavior of Heliconius and Laparus is a modified proboscis grooming behavior that originally served to clean the proboscis after contamination with particles

    Social response to population change and migration: the impact of population change on individuals and institutions

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    Population change over the last 40 years has greatly redistributed Midwest populations. Migration has long been a social response to change—both to changing capacities in the agricultural system and to socio-cultural attractions and opportunities in the urban-industrial areas. Some of the surplus agricultural population has moved to cities and suburbs. The result is a selective dismembering of many communities and an inordinate growth of others.https://lib.dr.iastate.edu/specialreports/1037/thumbnail.jp
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