545 research outputs found

    Henry David Thoreau (1817–1862)

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    In lieu of an abstract, here is the article\u27s first paragraph: The American author Henry David Thoreau is best known for his magnum opus Walden, or Life in the Woods (1854); second to this in popularity is his essay, “Resistance to Civil Government” (1849), which was later republished posthumously as “Civil Disobedience” (1866). His fame largely rests on his role as a literary figure exploring the wilds of the natural world, not as a philosopher

    Ruehl, Catherine (Death, 1906-04-27)

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    Address: 2215 Loth St.Age at death: 70 yrs.623/Pg 60/1906/F W M/Germany/Dr. P. M. Goor/W. L. Meyer/Spring GroveOriginal record filed in drawer labeled 'ROUS-RUNK'

    Detection, quantification and identification of fungal extracellular laccases using polyclonal antibody and mass spectrometry

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    This study presents a combined method to analyze extracellular fungal laccases using a new anti-laccase antibody together with the identification of tryptic laccase peptides by mass spectrometry (nanoLC-ESI-MS/MS). The polyclonal anti-laccase antibody LccCbr2 was raised against peptides designed from the copper binding region 11 of fungal laccases using in silico data obtained from GenBank database. As a consequence, detection requires denaturation of the enzymes due to the stable conformation of the copper binding region II. The specificity of the antibody was shown with denatured laccase Lcc1 of Coprinopsis cinerea and laccase of Hypholoma fasciculare. LccCbr2 detected amounts as low as 5 ng of highly purified laccase, indicating a possible use of the antibody for quantification of laccase proteins. Denatured extracellular laccases from culture supernatants of the basidiomycetes C. cinerea, H. fasciculare, Lentinula edodes, Mycena sp., Piriformospora indica, Pleurotus cornucopiae, Pleurotus ostreatus, Pycnoporus cinnabarinus, Trametes versicolor and furthermore the ascomycete Verpa conica were detected with apparent molecular masses between 60 and 70 kDa by LccCbr2. The identity of extracellular laccases from C cinerea, H. fasciculare, P ostreatus, P. cinnabarinus and T versicolor were verified by tryptic peptides using nanoLC-ESI-MS/MS. (C) 2007 Elsevier Inc. All rights reserved

    Reciprocal Transplant Reveals Trade-off of Resource Quality and Predation Risk in the Field

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    Balancing trade-offs between avoiding predators and acquiring food enables animals to maximize fitness. Quantifying their relative contribution to vital rates in nature is challenging because predator abundance and nutrient enrichment are often confounded. We employed a reciprocal transplant study design to separate these confounded effects on growth and reproduction of snails at wetland sites along a gradient of predator threats and phosphorus (P) enrichment associated with a canal. We held snails in mesh bags that allowed the passage of waterborne predator cues and fed them local or transplanted periphyton. Molluscivores were more abundant near the canal, and snails tethered near the canal suffered 33 % greater mortality than those tethered far from it (far sites). The greatest difference in snail growth rates was at the far sites where growth on far periphyton was 48 % slower than on P-enriched (near canal) periphyton. Close proximity to the canal reduced growth on near periphyton by 21 % compared to growth on the same periphyton far from the canal; there was no difference in growth rate on either periphyton type when snails were raised near the canal. Snails laid 81 % more egg masses at far sites than at near sites, regardless of periphyton origin. Top–down and bottom–up processes were elevated near the canal, and their effects canceled on growth, but not reproduction. Phenotypic trade-offs such as these may explain why some taxa show little response to nutrient enrichment, compared to others, or that the effects of nutrient enrichment may be context dependent

    Evaluating the contribution of physicochemical parameters to two common off-flavor compounds in a drinking water reservoir

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    Off-flavors, such as 2-methylisoborneol (MIB) and geosmin, are compounds that produce an earthy or musty taste and odor, which can negatively impact drinking water treatment and aquaculture products. Although these compounds were first identified as secondary metabolites of actinomycetes, cyanobacteria are considered to be the primary cause of off-flavors in freshwater lakes and ponds. Humans can detect off-flavors at very low concentrations (10 and 30 ng/L for MIB and geosmin, respectively), and, although not a health risk, off-flavors can promote distrust between consumers and water utilities. Removal of these compounds requires a large financial investment and is not guaranteed. Controlling ecological factors that promote off-flavor production may be more cost-effective in addition to improving the ecosystem as a whole. Due to their ability to produce toxins, cyanobacteria have been under particular scrutiny, and environmental factors promoting cyanobacterial blooms are relatively well known. Using some accepted paradigms surrounding cyanobacterial production, I conducted two limnocorral experiments that manipulated physicochemical conditions aimed at influencing phytoplankton community structure and, thereby, off-flavor production. The first experiment was conducted during fall 2013 and consisted of an unbalanced factorial design with four nitrogen-to-phosphorus (N:P) ratios and three nitrogen levels. I found that the addition of both N and P promoted MIB and effects were associated with cyanobacterial and diatom biovolume. The second experiment was a complete factorial design conducted during summer 2014 using the nutrient concentrations from the fall experiment that were found to best promote off-flavor. I also manipulated limnocorral mixing frequency to potentially affect growth and off-flavor production of diatoms, taxa not usually associated with off-flavor production. I found that MIB was positively correlated with diatoms, and negatively correlated with green algae and cryptophytes. I also found that geosmin was positively correlated with cyanobacteria. MIB and geosmin showed no concurrent trends throughout the second experiment, suggesting that different management approaches are required for each off-flavor compound. In general, off-flavors increased in both experiments under elevated nutrient conditions. Diatom biovolume was consistently correlated with MIB production, but contributions of cyanobacterial biovolume to off-flavors appeared to vary seasonally. These results indicate that lake managers should consider year-round control of nutrient loading and mixing patterns to better eliminate MIB and geosmin

    Aesthetic Fundamentalism in Weimar Poetry

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    This chapter takes a historical journey into the George-Kreis or George Circle, the mysterious coterie of followers that surrounded the poet and political visionary Stefan George. His many acolytes included Karl Wolfskehl, Ernst Bertram, and the historian Ernst Kantorowicz. The Circle saw itself not just as a counter-cultural, but also as a “counter-intellectual” movement, in radical opposition to the “official” Zeitgeist of Wilhelmine Germany. Even before the First World War, members of the Circle had voiced their critical distance to contemporary academic scholarship, their different educational ideals, and their hope for comprehensive spiritual renewal. It was only in the Weimar period, however, when George became an iconic figure and his disciples played a more prominent role in public debates, that the ideas and ideals of the Circle came to have a palpable effect in German intellectual life.</p

    How quickly do cloud droplets form on atmospheric particles?

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    The influence of aerosols on cloud properties is an important modulator of the climate system. Traditional Köhler theory predicts the equilibrium concentration of cloud condensation nuclei (CCN); however, it is not known to what extent particles exist in the atmosphere that may be prevented from acting as CCN by kinetic limitations. We measured the rate of cloud droplet formation on atmospheric particles sampled at four sites across the United States during the summer of 2006: Great Smoky Mountain National Park, TN; Bondville, IL; Houston, TX; and the Atmospheric Radiation Measurement Program Southern Great Plains site near Lamont, OK. We express droplet growth rates with the mass accommodation coefficient (α), and report values of α measured in the field normalized to the mean α measured for lab-generated ammonium sulfate (AS) particles (i.e., &amp;alpha;&apos;=α/&amp;alpha;&lt;sub&gt;AS&lt;/sub&gt;). Overall, 59% of ambient CCN grew at a rate similar to AS. We report the fraction of CCN that were &quot;low-&amp;alpha;&apos; &quot; (&amp;alpha;&apos;&lt;10&lt;sup&gt;&amp;minus;1&lt;/sup&gt;, corresponding to α&amp;lt;1.5&amp;times;10&lt;sup&gt;&amp;minus;2&lt;/sup&gt;). Of the 16 days during which these measurements were made, 8 had relatively few low-&amp;alpha;&apos; CCN (&amp;lt;16%), 6 had moderate low-&amp;alpha;&apos; fractions (27% to 59%), and 2 had large low-&amp;alpha;&apos; fractions (&amp;gt;82% during at least one ~30 min period). Day to day variability was greatest in Tennessee and Illinois, and low-&amp;alpha;&apos; particles were most prevalent on days when back trajectories suggested that air was arriving from aloft. The highest fractions of low-&amp;alpha;&apos; CCN in Houston and Illinois occurred around local noon, and decreased later in the day. These results suggest that for some air masses, accurate quantification of CCN concentrations may need to account for kinetic limitations
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