995 research outputs found

    NUV/Blue spectral observations of sprites in the 320-460 nm region: N2{\mathrm N_2} (2PG) Emissions

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    A near-ultraviolet (NUV) spectrograph (320-460 nm) was flown on the EXL98 aircraft sprite observation campaign during July 1998. In this wavelength range video rate (60 fields/sec) spectrographic observations found the NUV/blue emissions to be predominantly N2 (2PG). The negligible level of N2+ (1NG) present in the spectrum is confirmed by observations of a co-aligned, narrowly filtered 427.8 nm imager and is in agreement with previous ground-based filtered photometer observations. The synthetic spectral fit to the observations indicates a characteristic energy of ~1.8 eV, in agreement with our other NUV observations.Comment: 7 pages, 2 figures, 1 table, JGR Space Physics "Effects of Thunderstorms and Lightning in the Upper Atmosphere" Special Sectio

    Preliminary Report on the Distribution of Bottom Organisms in West Lake Okoboji, Iowa

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    Little is known of the bottom fauna of the locality. This passage is taken from an Extension Bulletin of the State University of Iowa which describes the Iowa Lakeside Laboratory on West Lake Okoboji and its facilities for biological investigations. It should be stressed at the outse.t that there are few lakes which do not share with Okoboji this relatively unexplored state of their bottom biota. A study was begun in July 1950 with a view to eventually answering the following questions: 1. What is the distribution of macroscopic bottom dwelling animals in the lake? 2. Does this distribution follow a pattern that can be correlated with environmental factors such as the nature of bottom deposits, slope of the bottom in various regions, temperature, dissolved gases in the water, currents in the lake and others

    Regioselective Radical Arene Amination for the Concise Synthesis of <i>ortho</i>-Phenylenediamines.

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    The formation of arene C-N bonds directly from C-H bonds is of great importance and there has been rapid recent development of methods for achieving this through radical mechanisms, often involving reactive N-centered radicals. A major challenge associated with these advances is that of regiocontrol, with mixtures of regioisomeric products obtained in most protocols, limiting broader utility. We have designed a system that utilizes attractive noncovalent interactions between an anionic substrate and an incoming radical cation in order to guide the latter to the arene ortho position. The anionic substrate takes the form of a sulfamate-protected aniline and telescoped cleavage of the sulfamate group after amination leads directly to ortho-phenylenediamines, key building blocks for a range of medicinally relevant diazoles. Our method can deliver both free amines and monoalkyl amines allowing access to unsymmetrical, selectively monoalkylated benzimidazoles and benzotriazoles. As well as providing concise access to valuable ortho-phenylenediamines, this work demonstrates the potential for utilizing noncovalent interactions to control positional selectivity in radical reactions

    Paving the way: an evaluation of small business support programs in the Kivalliq region of Nunavut

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    Thesis (M.A.) University of Alaska Fairbanks, 2018Small businesses in Nunavut face many opportunities and challenges. The Government of Nunavut and Government of Canada have expressed a commitment to support small business development in Nunavut to promote economic development and improve socioeconomic conditions for Nunavummiut. The question is: how can they best do that? Nunavut has developed a complex business service network to support small business development. The network provides many products and services, particularly funding opportunities and advisory services. This research analyzes the history of economic and business development in the Kivalliq (southwest) region of Nunavut. This includes precolonial Inuit economic institutions, which are vastly different from western models, and the utilized strategies in the Nunavut business service network. Twenty-four open ended interviews were conducted with entrepreneurs and business service network employees to evaluate the realities of small businesses in Nunavut. Interviews were designed and studied from a social constructionist and phenomenological perspective. The primary issues that were identified in the Nunavut business service network were: low accountability; burdensome bureaucracy; poor effectiveness; lack of trust in business service employees; poor transparency; unreliable maintenance of confidentiality; and oversaturation of funders; and a need for greater communication between organizations. Most of these issues related more to non-repayable contributions programs than other forms of business service organizations. Contribution programs will be explored in greater detail. Recommendations were guided by ideas to increase the amount of support, both from a business counselling and funding perspective, for established businesses as opposed to start-ups; a need for greater accountability and transparency; methods to increase trust in business service employees; ways to improve communications between service organizations; and a need to reduce bureaucracy and streamline application processes. The final recommendations include restructuring financing programs, particularly contribution financing programs; establishing a mentorship program; creating a single-portal streamlined application for funding and site for information; adding additional metrics of evaluation, particularly for contribution financing programs; creating a pool of board members for business funding reviews; starting a business incubator or business advisory-only program; and establishing a stronger partnership with the Nunavut Arctic College in delivering training programs for business owners

    Overtly anaphoric control in type logical grammar

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    In this paper we analyse anaphoric pronouns in control sentences and we investigate the implications of these kinds of sentences in relation to the Propositional Theory versus Property Theory question. For these purposes, we invoke the categorial calculus with limited contraction, a conservative extension of Lambek calculus that builds contraction into the logical rules for a customized slash type-constructor.Peer ReviewedPostprint (author's final draft

    Condensed Tannins in Tropical Legumes: Concentration, Astringency and Effects on the Nutrition of Ruminants

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    A feeding trial was carried out to determine the effect of extractable condensed tannins (ECT) concentration and tannin astringency in tropical legumes on nitrogen (N) digestion by sheep. Test legumes were Desmodium ovalifolium (Do) and Flemingia macrophylla (Fm) which had similar concentrations of Extractable CT (9% DM) but tannins with different degree of astringency (Do, 0.6 and Fm, 0.3 g protein bound/g of ECT). Chopped sun-dried forage of each legume was sprayed with either water (control) or polyethylene glycol (PEG, 3.5% DM) to reduce ECT and fed to 8 sheep with ruminal and duodenal canulas arranged in a replicated 4 x 4 Latin Square changeover design. Greater (P\u3c0.05) N flow to duodenum, and fecal N were observed with Fm than with Do. Estimates of escape N were similar (58 to 61%) for both legumes. Reduction of ECT with PEG in both legumes (9.0-9.4 to 4.7-5.4%) resulted in lower (P\u3c0.05) proportion of N reaching the duodenum. Results indicate that concentration of ECT had a greater effect on N digestion by sheep than tannin astringency

    A Validated Software Application to Measure Fiber Organization in Soft Tissue

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    The mechanical behavior of soft connective tissue is governed by a dense network of fibrillar proteins in the extracellular matrix. Characterization of this fibrous network requires the accurate extraction of descriptive structural parameters from imaging data, including fiber dispersion and mean fiber orientation. Common methods to quantify fiber parameters include fast Fourier transforms (FFT) and structure tensors, however, information is limited on the accuracy of these methods. In this study, we compared these two methods using test images of fiber networks with varying topology. The FFT method with a band-pass filter was the most accurate, with an error of 0.71 ± 0.43 degrees in measuring mean fiber orientation and an error of 7.4 ± 3.0% in measuring fiber dispersion in the test images. The accuracy of the structure tensor method was approximately 4 times worse than the FFT bandpass method when measuring fiber dispersion. A free software application, FiberFit, was then developed that utilizes an FFT band-pass filter to fit fiber orientations to a semicircular von Mises distribution. FiberFit was used to measure collagen fibril organization in confocal images of bovine ligament at magnifications of 63x and 20x. Grayscale conversion prior to FFT analysis gave the most accurate results, with errors of 3.3 ± 3.1 degrees for mean fiber orientation and 13.3 ± 8.2% for fiber dispersion when measuring confocal images at 63x. By developing and validating a software application that facilitates the automated analysis of fiber organization, this study can help advance a mechanistic understanding of collagen networks and help clarify the mechanobiology of soft tissue remodeling and repair

    The Risk of Hepatotoxicity with Fluoroquinolones: A National Case-Control Safety Study

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    Purpose. Fluoroquinolones are generally considered safe and well-tolerated. However, suspected fluoroquinolone induced hepatotoxicity has been increasingly reported, but data are lacking. Thus, the objective of this study was to assess the risk of hepatotoxicity in patients using fluoroquinolones compared to non-users. Methods. National Veterans Affairs (VA) hospital admissions were assessed between January 1, 2002 and December 31, 2008. Our case-control study matched patients with a primary diagnosis of hepatotoxicity (cases) to those with myocardial infarction (controls) on admission date (matched up to 1:6). Conditional logistic regression was used to compute adjusted odds ratios (OR) and 95% confidence intervals (CI) of hepatotoxicity associated with fluoroquinolone exposure. Results. Our study included 7,862 cases and 45,512 matched controls. The majority of study patients were white (63.4%), males (97.7%), with a mean age of 61 years. After adjusting for confounders, fluoroquinolone use was significantly associated with a 20% increased risk of hepatotoxicity development (OR 1.20, 95% CI 1.04-1.38) compared to non-users. A statistically significant increased risk of hepatotoxicity was associated with ciprofloxacin use individually (OR 1.29, 95% CI 1.05-1.58), but not with levofloxacin or moxifloxacin use. Conclusion. The use of fluoroquinolones was associated with an increased risk of hepatotoxicity relative to non-users in our national VA study population
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