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941.
High spatial and temporal resolution maps of sea surface temperature (SST) have numerous applications in coastal and estuarine systems. A climatology map, tracking SST as a function of year-day, was produced at Southern New England using 53 Landsat TM and ETM+ thermal infrared data. A recursive curve-fitting algorithm was used to fit these data and eliminate cloud contamination, resulting in an average daily temperature at every 60-m pixel. The climatology was validated against long-term in situ records that were analyzed with the same techniques. The results show, as expected, that isolated and shallow water bodies undergo more extreme temperature variation (−2 to 25 °C) than deeper, well-connected embayments (1 to 21 °C) or the coastal ocean (4 to 18 °C). The coastal ocean is shown to lag insolation and shallow lakes by up to 44 days, with embayments showing a gradation between these extremes. Despite the subtle temperature range variation, there is rich detail in the spatial patterns which are relevant to the applied sciences of coastal and estuarine systems. The spatial pattern of the climatology reveals anomalous patterns, such as occur where anthropogenic forcing alters climatological patterns. The heat budget of Mount Hope Bay in northeast Narragansett Bay has anthropogenic thermal input from a large power plant, and this input is reflected in the climatology. From the results, it is seen that Narragansett Bay has, on average, a mean annual temperature of 11.86±0.41 °C, while the Mount Hope Bay system is consistently warmer at 12.30±0.21 °C and shows a delayed response to autumn cooling. The long history of Landsat data acquisition can be used to create a climatology of coastal and estuarine scale dynamics at an order of magnitude finer scale resolution than AVHRR climatologies. 相似文献
942.
While there has been substantial interest in using e-science and cyberinfrastructure technologies to enable synchronous remote participation in experimental research, the details of such participation are in question. On the one hand, there is a desire to give remote participants the same views and capabilities that they would have as local participants. On the other hand, there are settings where experimental specimens and apparatus are large and difficult to manipulate effectively or view from a remote vantage point. This article argues for more novel forms of remote participation by drawing on exploratory interview and observation data gathered in civil engineering laboratories. It is shown that, while experiments are in progress, the engineers studied focus primarily on detecting and preventing specimen failures, and that their unease about remote participation stems from doubts about the ability of remote participants to detect failures adequately. It is argued that this presents the opportunity to consider novel roles for remote participants that exploit the features of e-science technologies. 相似文献
943.
Dunn Elizabeth W.; Biesanz Jeremy C.; Human Lauren J.; Finn Stephanie 《Canadian Metallurgical Quarterly》2007,92(6):990
Positive self-presentation may have beneficial consequences for mood that are typically overlooked. Across a series of studies, participants underestimated how good they would feel in situations that required them to put their best face forward. In Studies 1 and 2A, participants underestimated the emotional benefits of interacting with an opposite sex stranger versus the benefits of interacting with a romantic partner. In Study 2B, participants who were instructed to engage in self-presentation felt happier after interacting with their romantic partner than participants who were not given this instruction, although other participants serving as forecasters did not anticipate such benefits. Increasing the generalizability of this self-presentation effect across contexts, the authors demonstrated that participants also underestimated how good they would feel before and after being evaluated by another person (Studies 3 and 4). This failure to recognize the affective benefits of putting one's best face forward may underlie forecasting errors regarding the emotional consequences of the most common forms of social interactions. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
944.
Mistry Rashmita S.; Biesanz Jeremy C.; Taylor Lorraine C.; Burchinal Margaret; Cox Martha J. 《Canadian Metallurgical Quarterly》2004,40(5):727
The current study examines relations of mean-level estimates, linear changes, and instability in income and family processes to child outcomes and addresses whether income, through its impact on family functioning, matters more for children living in poverty. Temporal changes and instability in family processes, but not income, predicted children's adjustment. Cross-sectional mediational analyses indicated that for families living at the poverty threshold, family processes fully mediated the effect of average income over the study period on social behavior but only partially mediated its effect on cognitive-linguistic development. The strength of these associations diminished as average income exceeded the poverty threshold. That is, income had a greater impact on the family functioning and development of poor children than of nonpoor children. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
945.
How do observers search through familiar scenes? A novel panoramic search method is used to study the interaction of memory and vision in natural search behavior. In panoramic search, observers see part of an unchanging scene larger than their current field of view. A target object can be visible, present in the display but hidden from view, or absent. Visual search efficiency does not change after hundreds of trials through an unchanging scene (Experiment 1). Memory search, in contrast, begins inefficiently but becomes efficient with practice. Given a choice between vision and memory, observers choose vision (Experiments 2 and 3). However, if forced to use their memory on some trials, they learn to use memory on all trials, even when reliable visual information remains available (Experiment 4). The results suggest that observers make a pragmatic choice between vision and memory, with a strong bias toward visual search even for memorized stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
946.
European Food Research and Technology - In Kuhmilch und Stutenmilch und in daraus hergestellten Milchprodukten wurde nach einem früher entwickelten Verfahren der Gehalt an flüchtigen und... 相似文献
947.
948.
Jeremy R. Court S. John Pirt 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1981,31(1):235-240
Fed batch culture was used to investigate penicillin production when the growth of Penicillium chrysogenum was limited by the supply of either sucrose and or ammonium ions. It was found that a ‘quasi steady state’ (in which the growth rate was virtually equal to the dilution rate) could be established under these conditions. Some metabolic parameters (specific sucrose consumption rate and growth yields) were dependent on the ratio of sucrose: ammonium ions in the feed medium over a range of ammonium concentrations both above and below the double substrate-limited point. The maximum specific rate of penicillin production required the supply of a large excess of ammonium ion, about five times the growth-limiting level. That is, the ratio of ammonium-nitrogen: sucrose, fed to the (sucrose-limited) culture, was 0.11 and the residual ammonium ion concentration was in excess of 18 mmol dm?3, at a dry biomass concentration of 0.6%. 相似文献
949.
Meyer MJ Schieffer GM Moeker EK Brodersen JJ Swenson OF Borgerding AJ 《Analytical chemistry》2004,76(6):1702-1707
We report results for a new gas chromatography detector that is comparatively sensitive and far more selective for aromatic compounds than the traditional photoionization detector. The detection means is multiphoton ionization at atmospheric pressure. The ionization source in these experiments is a diode-pumped passively Q-switched microchip laser operating at 266 nm. Experiments were conducted with the detector interfaced to a fast gas chromatograph. For <20 s elution time, limits of detection were <1 pg for toluene, ethylbenzene, xylenes, and isopropylbenzene; the limit of detection for benzene is approximately 10 pg. Detector response was linear over 5 orders of magnitude, including these low levels. Negligible signals were observed for nonaromatic ketones, aldehydes, ethers, and cycloalkanes at levels as high as 0.1 microg (10 mg/L concentration). Detector efficiency after fast GC separation was 0.002% when using a detector cell with a radius of 1.1 cm and a purge gas flow of 500 mL/min. The advantages of this detector are further illustrated by the fast GC analysis of fuel samples. 相似文献
950.
Flinders J DeFina SC Brackett DM Baugh C Wilson C Dieckmann T 《Chembiochem : a European journal of chemical biology》2004,5(1):62-72
Ribonucleic acids are an attractive drug target owing to their central role in many pathological processes. Notwithstanding this potential, RNA has only rarely been successfully targeted with novel drugs. The difficulty of targeting RNA is at least in part due to the unusual mode of binding found in most small-molecule-RNA complexes: the ligand binding pocket of the RNA is largely unstructured in the absence of ligand and forms a defined structure only with the ligand acting as scaffold for folding. Moreover, electrostatic interactions between RNA and ligand can also induce significant changes in the ligand structure due to the polyanionic nature of the RNA. Aptamers are ideal model systems to study these kinds of interactions owing to their small size and the ease with which they can be evolved to recognize a large variety of different ligands. Here we present the solution structure of an RNA aptamer that binds triphenyl dyes in complex with malachite green and compare it with a previously determined crystal structure of a complex formed with tetramethylrosamine. The structures illustrate how the same RNA binding pocket can adapt to accommodate both planar and nonplanar ligands. Binding studies with single- and double-substitution mutant aptamers are used to correlate three-dimensional structure with complex stability. The two RNA-ligand complex structures allow a discussion of structural changes that have been observed in the ligand in the context of the overall complex structure. Base pairing and stacking interactions within the RNA fold the phosphate backbone into a structure that results in an asymmetric charge distribution within the binding pocket that forces the ligand to adapt through a redistribution of the positive partial charge. 相似文献