3,549 research outputs found

    Hot methane line lists for exoplanet and brown dwarf atmospheres

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    We present comprehensive experimental line lists of methane (CH4) at high temperatures obtained by recording Fourier transform infrared emission spectra. Calibrated line lists are presented for the temperatures 300 - 1400 degC at twelve 100 degC intervals spanning the 960 - 5000 cm-1 (2.0 - 10.4 microns) region of the infrared. This range encompasses the dyad, pentad and octad regions, i.e., all fundamental vibrational modes along with a number of combination, overtone and hot bands. Using our CH4 spectra, we have estimated empirical lower state energies (Elow in cm-1) and our values have been incorporated into the line lists along with line positions (cm-1) and calibrated line intensities (S' in cm molecule-1). We expect our hot CH4 line lists to find direct application in the modeling of planetary atmospheres and brown dwarfs.Comment: Supplementary material is provided via the Astrophysical Journal referenc

    College Students’ Attitudes toward Debt

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    College student debt has gained much attention. This article uses survey data to examine the influence of psychological factors on college student attitudes toward debt. In the sample of 283 undergraduates enrolled in a personal finance elective course, financial self-confidence was significantly related to debt attitude, indicating that less financially self-confident students tended to have more positive attitudes toward debt. Two other psychological factors, ability to delay gratification and comparing oneself to others, were not significantly related to debt attitudes. Among the control variables, only gender was significantly related; women had more negative attitudes toward debt than men. College major, involvement with parents about personal finance, and financial knowledge were not significantly related to student attitudes toward debt. Future researchers should consider reexamining the use of the scales used in this research. Although the scales had been used by previous researchers, they may have less relevance to young adults whose debt attitudes were no doubt influenced by the Great Recession of 2007-2009

    College Students’ Attitudes toward Debt

    Get PDF
    College student debt has gained much attention. This article uses survey data to examine the influence of psychological factors on college student attitudes toward debt. In the sample of 283 undergraduates enrolled in a personal finance elective course, financial self-confidence was significantly related to debt attitude, indicating that less financially self-confident students tended to have more positive attitudes toward debt. Two other psychological factors, ability to delay gratification and comparing oneself to others, were not significantly related to debt attitudes. Among the control variables, only gender was significantly related; women had more negative attitudes toward debt than men. College major, involvement with parents about personal finance, and financial knowledge were not significantly related to student attitudes toward debt. Future researchers should consider reexamining the use of the scales used in this research. Although the scales had been used by previous researchers, they may have less relevance to young adults whose debt attitudes were no doubt influenced by the Great Recession of 2007-2009.Faculty Sponsor: Dr. Brenda J. Cud

    Pressure to Perform: Is Cardiac Output Estimation from Arterial Waveforms Good Enough for Routine Use?

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    journal articleBiomedical Informatic

    Recent applications of NMR spectroscopy in plant metabolomics

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    Recent research has established NMR as a key method for high-throughput comparative analysis of plant extracts. We discuss recent examples of the use of NMR to provide metabolomic data for various applications in plant science and look forward to the key role that NMR will play in data provision for plant systems biology

    Absolute differential positronium-formation cross sections

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    The first absolute experimental determinations of the differential cross-sections for the formation of ground-state positronium are presented for He, Ar, H2 and CO2 near 0○. Results are compared with available theories. The ratio of the differential and integrated cross-sections for the targets exposes the higher propensity for forward-emission of positronium formed from He and H2

    Sertoli Cell Adenylyl Cyclase Is Stimulated by a Factor Associated with Germ Cells

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74745/1/j.1749-6632.1984.tb38341.x.pd

    Metabolomic analysis of Arabidopsis reveals hemiterpenoid glycosides as products of a nitrate ion-regulated, carbon flux overflow

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    An understanding of the balance between carbon and nitrogen assimilation in plants is key to future bioengineering for a range of applications. Metabolomic analysis of the model plant, Arabidopsis thaliana, using combined NMR-MS revealed the presence of two hemiterpenoid glycosides that accumulated in leaf tissue, to ~1% dry weight under repeated nitrate-deficient conditions. The formation of these isoprenoids was correlated with leaf nitrate concentrations that could also be assayed in the metabolomic data using a unique flavonoid–nitrate mass spectral adduct. Analysis of leaf and root tissue from plants grown in hydroponics with a variety of root stressors identified the conditions under which the isoprenoid pathway in leaves was diverted to the hemiterpenoids. These compounds were strongly induced by root wounding or oxidative stress and weakly induced by potassium deficiency. Other stresses such as cold, saline, and osmotic stress did not induce the compounds. Replacement of nitrate with ammonia failed to suppress the formation of the hemiterpenoids, indicating that nitrate sensing was a key factor. Feeding of intermediates was used to study aspects of 2-C-methyl-d-erythritol-4-phosphate pathway regulation leading to hemiterpenoid formation. The formation of the hemiterpenoids in leaves was strongly correlated with the induction of the phenylpropanoids scopolin and coniferin in roots of the same plants. These shunts of photosynthetic carbon flow are discussed in terms of overflow mechanisms that have some parallels with isoprene production in tree species
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