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Makris NC Ratilal P Symonds DT Jagannathan S Lee S Nero RW 《Science (New York, N.Y.)》2006,311(5761):660-663
Until now, continental shelf environments have been monitored with highly localized line-transect methods from slow-moving research vessels. These methods significantly undersample fish populations in time and space, leaving an incomplete and ambiguous record of abundance and behavior. We show that fish populations in continental shelf environments can be instantaneously imaged over thousands of square kilometers and continuously monitored by a remote sensing technique in which the ocean acts as an acoustic waveguide. The technique has revealed the instantaneous horizontal structural characteristics and volatile short-term behavior of very large fish shoals, containing tens of millions of fish and stretching for many kilometers. 相似文献
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Chakrapani V Angus JC Anderson AB Wolter SD Stoner BR Sumanasekera GU 《Science (New York, N.Y.)》2007,318(5855):1424-1430
Undoped, high-quality diamond is, under almost all circumstances, one of the best insulators known. However, diamond covered with chemically bound hydrogen shows a pronounced conductivity when exposed to air. This conductivity arises from positive-charge carriers (holes) and is confined to a narrow near-surface region. Although several explanations have been proposed, none has received wide acceptance, and the mechanism remains controversial. Here, we report the interactions of hydrogen-terminated, macroscopic diamonds and diamond powders with aqueous solutions of controlled pH and oxygen concentration. We show that electrons transfer between the diamond and an electrochemical reduction/oxidation couple involving oxygen. This charge transfer is responsible for the surface conductivity and also influences contact angles and zeta potentials. The effect is not confined to diamond and may play a previously unrecognized role in other disparate systems. 相似文献
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Lahann J Mitragotri S Tran TN Kaido H Sundaram J Choi IS Hoffer S Somorjai GA Langer R 《Science (New York, N.Y.)》2003,299(5605):371-374
We report the design of surfaces that exhibit dynamic changes in interfacial properties, such as wettability, in response to an electrical potential. The change in wetting behavior was caused by surface-confined, single-layered molecules undergoing conformational transitions between a hydrophilic and a moderately hydrophobic state. Reversible conformational transitions were confirmed at a molecular level with the use of sum-frequency generation spectroscopy and at a macroscopic level with the use of contact angle measurements. This type of surface design enables amplification of molecular-level conformational transitions to macroscopic changes in surface properties without altering the chemical identity of the surface. Such reversibly switching surfaces may open previously unknown opportunities in interfacial engineering. 相似文献
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Venkataramanan Ragothaman Sreekumar Chirukandoth Anilkumar Rishipal Selvaraj P. Vidhya Nainar M. Mathagowder Iyue 《Tropical animal health and production》2010,42(5):1027-1029
Silage, which is anaerobically fermented green fodder, is valued throughout the world as a source of animal feed during lean
months. Several farms in India use carbohydrate sources like jaggery or molasses at 2% for preparation of silage, and this
increases cost of production. The present study was undertaken to assess the effect of jaggery on quality and intake of maize
silage, with an objective to find out whether additional carbohydrate source is essential in preparation of silage using green
maize. Three silage types, one without jaggery (A), the second with 1% jaggery (B), and the third with 2% jaggery (C) were
prepared in cylindrical bins under similar conditions. They were compared for colour, pH, lactic acid bacteria count, lactic
acid content, proximate composition and silage intake by sheep. Silage type C with 2% jaggery was significantly different
from the other two types with values of 3.98 and 805.66 g for pH and mean silage intake, respectively. Even though the values
of pH and dry matter intake for all three silage types were within normal levels, silage type C was significantly superior
in terms of fermentation and palatability. The method of preparation followed could be ideal for small holder farmers requiring
less quantity of silage. 相似文献
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The hypoglycemic effect of the aqueous extract of the seeds of Mucuna pruriens was investigated in normal, glucose load conditions and streptozotocin (STZ)-induced diabetic rats. In normal rats, the aqueous extract of the seeds of Mucuna pririens (100 and 200 mg/kg body weight) significantly (P<0.001) reduced the blood glucose levels after an oral glucose load from 127.5+/-3.2 to 75.6+/-4.8 mg% 2 h after oral administration of seed extract. It also significantly lowered the blood glucose in STZ diabetic rats from 240.5+/-7.2 to 90.6+/-5.6 mg% after 21 days of daily oral administration of the extract (P<0.001). Thus, this study shows that M. pruriens has an anti-hyperglycemic action and it could be a source of hypoglycemic compounds. 相似文献
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