Ice flow velocity is used to estimate ice mass changes in glaciers and is a significant indicator of the stability of the Antarctica ice sheet in global change studies. The existing regional Antarctica ice flow speed ...
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Ice flow velocity is used to estimate ice mass changes in glaciers and is a significant indicator of the stability of the Antarctica ice sheet in global change studies. The existing regional Antarctica ice flow speed maps are usually derived from radar or optical satellite observations of modern satellites since the 1970s. This paper presents a new analytical photogrammetric method for estimating Antarctica ice flow velocity fields by using film-based stereo ARGON photographs collected in the 1960s. The key of the proposed innovative method is a parallax decomposition that separates the effect of the terrain relief from the ice flow motion. An innovative implementation strategy is developed by using a framework that involves key techniques of hierarchical stereo image matching, ice flow direction determination, parallax decomposition, and ice flow speed estimation. This method is applied in the Rayner glacier in eastern Antarctica by using two sets of ARGON images with a two-month interval in 1963. The produced digital terrain model and speed map achieved a ground position accuracy of 61 m and a speed accuracy of 70 m a(-1). A comparison with recent products from 2000 to 2010 shows no significant topographic changes in the study area. Furthermore, the speed around the grounding line remained at the same level, while the speed in the ice shelf front decreased by 73 m a(-1.) The ice shelf front advanced by approximately 7 km over more than 40 years. Overall, the observation results indicate favorable conditions for the stability of the Rayner glacier-ice shelf system.
The emergence of multidrug-resistant (MDR) microbes caused by overuse of antibiotics leads to urgent demands for novel antibiotics exploration. Our recent data showed that Ly2.1-3 (a novel lymphocyte antigen 6 (Ly6) g...
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The emergence of multidrug-resistant (MDR) microbes caused by overuse of antibiotics leads to urgent demands for novel antibiotics exploration. Our recent data showed that Ly2.1-3 (a novel lymphocyte antigen 6 (Ly6) gene cluster) were proteins with cationic nature and rich in cysteine content, that are characteristic of antimicrobial peptides (AMPs) and their expression were all significantly up-regulated after challenge with lipopolysaccharide (LPS). These strongly suggested that Ly2.1-3 are potential AMPs, but firm evidence are lacking. Here, we clearly showed that the recombinant proteins of Ly2.1-3 were capable of killing Gram-negative bacteria Aeromonas hydrophila and Escherichia coli, while they had little bactericidal activity against the Gram-positive bacteria Staphylococcus aureus and Bacillus subtilis. We also showed that recombinant proteins Ly2.1-3 (rLy2.1-3) were able to bind to the Gram-negative bacteria A. hydrophila, E. coli and the microbial signature molecule LPS, but not to the Gram-positive bacteria S. aureus and B. subtilis as well as the microbial signature molecule LTA. Moreover, the Scatchard analysis revealed that rLy2.1-3 could specifically bind to LPS. Finally, we found that Ly2.1-3 were not cytotoxic to mammalian cells. All these together indicate that Ly2.1-3 can function as AMPs.
As the key part of chip-scale atomic clocks(CSACs), the vapor cell directly determines the volume, stability,and power consumption of the CSAC. The reduction of the power consumption and CSAC volumes demands the manuf...
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As the key part of chip-scale atomic clocks(CSACs), the vapor cell directly determines the volume, stability,and power consumption of the CSAC. The reduction of the power consumption and CSAC volumes demands the manufacture of corresponding vapor cells. This overview presents the research development of vapor cells of the past few years and analyzes the shortages of the current preparation technology. By comparing several different vapor cell preparation methods, we successfully realized the micro-fabrication of vapor cells using anodic bonding and deep silicon etching. This cell fabrication method is simple and effective in avoiding weak bonding strengths caused by alkali metal volatilization during anodic bonding under high ***, the vapor cell D2 line was characterized via optical-absorption resonance. According to the results,the proposed method is suitable for CSAC.
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