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Purkis Sam J. Gleason Arthur C. R. Purkis Charlotte R. Dempsey Alexandra C. Renaud Philip G. Faisal Mohamed Saul Steven Kerr Jeremy M. 《Coral reefs (Online)》2019,38(3):467-488
Coral Reefs - With compelling evidence that half the world’s coral reefs have been lost over the last four decades, there is urgent motivation to understand where reefs are located and their... 相似文献
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Bromoform (tribromomethane, CHBr3), one of the trihalomethanes, is a chlorination byproduct in cooling water of power plants and industrial complexes. We used the distribution of bromoform in seawater to monitor the movement of cooling water from the Youngkwang Nuclear Power Plant (YNPP) located on the West Coast of Korea. Bromoform concentrations were highest, 124 g l–1, in surface water near the outlet of YNPP and decreased linearly with distance from the outlet, mimicking the dissipation of cooling water discharged from the power plant. This byproduct of chlorination is thus a potential tracer of coastal water masses, due to its conservative behavior in the cooling water, low natural background in seawater, and easy analytical detection. 相似文献
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Sam?Van?WassenberghEmail author Anthony?Herrel Dominique?Adriaens Peter?Aerts 《Zoomorphology》2004,123(2):81-93
Some species of Clariidae (air breathing catfishes) have extremely well developed (hypertrophied) jaw closing muscles that increase the maximal biting force of these species. As these enlarged jaw muscles tightly cover the suspensoria, which are firmly connected to the neurocranium, we expect diminished lateral expansions during suction for species with hypertrophied jaw muscles. In turn, this could imply a reduced suction performance for these species. Compared to Clarias gariepinus, which has relatively small jaw closers, Clariallabes longicauda shows a clear hypertrophy of the jaw adductors. A kinematic analysis of prey capture in these two species is presented here. As predicted, Clariallabes longicauda shows less lateral expansion (average abduction of the hyoids of 19.0°) than Clarias gariepinus (abduction of 31.1°). However, our data indicate that the decrease in lateral expansion capacity in the species with excessive adductor development is compensated for by a larger and faster ventral expansion of the buccal cavity by depression of the hyoid. 相似文献
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Hayes JR English LL Carr LE Wagner DD Joseph SW 《Applied and environmental microbiology》2004,70(10):6005-6011
The potential impact of food animals in the production environment on the bacterial population as a result of antimicrobial drug use for growth enhancement continues to be a cause for concern. Enterococci from 82 farms within a poultry production region on the eastern seaboard were isolated to establish a baseline of susceptibility profiles for a number of antimicrobials used in production as well as clinical environments. Of the 541 isolates recovered, Enterococcus faecalis (53%) and E. faecium (31%) were the predominant species, while multiresistant antimicrobial phenotypes were observed among all species. The prevalence of resistance among isolates of E. faecalis was comparatively higher among lincosamide, macrolide, and tetracycline antimicrobials, while isolates of E. faecium were observed to be more frequently resistant to fluoroquinolones and penicillins. Notably, 63% of the E. faecium isolates were resistant to the streptogramin quinupristin-dalfopristin, while high-level gentamicin resistance was observed only among the E. faecalis population, of which 7% of the isolates were resistant. The primary observations are that enterococci can be frequently isolated from the poultry production environment and can be multiresistant to antimicrobials used in human medicine. The high frequency with which resistant enterococci are isolated from this environment suggests that these organisms might be useful as sentinels to monitor the development of resistance resulting from the usage of antimicrobial agents in animal production. 相似文献
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A theoretical study of alkene epoxidation, by the high-valent iron-oxo species (Compound I) of cytochrome P450, reveals a multi-state scenario in which the different products are generated in a state specific manner. All the low-spin doublet state processes are effectively concerted epoxide producing pathways. By contrast, all the high-spin quartet processes are stepwise and either lead to epoxide that does not conserve the isomeric identity of the alkene (cis or trans), or/and to by-products such as suicidal complexes and aldehydes. The product/state inventory is the following: (a) The epoxide with conserved alkene stereochemistry is generated from the low-spin doublet states of Compound I in a nonsynchronous but effectively concerted pathways that involve carbon radical (with Fe(III) and Fe(IV)) and cationic intermediates. (b) The epoxide with scrambled alkene stereochemistry is obtained from the quartet high-spin radical intermediate (with Fe(IV)). (c) The suicidal complex, with a C-N bond between the alkene and the porphyrin, is obtained from the high-spin cationic state that possesses one electron in the sigma xy* orbital (the antibonding Fe-N orbital made from dxy and nitrogen sigma-hybrids). (d) The aldehyde by-product is obtained from the high-spin cationic state that possesses one electron in the sigma xy* orbital (the antibonding O-Fe-S orbital made from dz2 and the oxo and sulfur sigma-hybrids). Factors controlling the competition between these processes are discussed. 相似文献
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Solution-phase and solid-phase permanganate oxidation reactions of thymine acetic acid were investigated by spectroscopy. The spectral data showed the formation of a stable organomanganese intermediate, which was responsible for the rise in the absorbance at 420 nm. This result enables unambiguous interpretation of the absorbance change at 420 nm, as the intermediate permanganate ions could be isolated on the solid supports. 相似文献