Monitoring and visualizing information resources

The continuous increase in information necessitates monitoring and display techniques that maximize comprehension yet minimize effort. In this paper, we discuss the use of hypertools, confluent zoom and graphical encoding of text as solutions to this problem, and we introduce Irwin and information resource and display tool

Calibration of the LIGO gravitational wave detectors in the fifth science run

The Laser Interferometer Gravitational Wave Observatory (LIGO) is a network of three detectors built to detect local perturbations in the space–time metric from astrophysical sources. These detectors, two in Hanford, WA and one in Livingston, LA, are power-recycled Fabry-Perot Michelson interferometers. In their fifth science run (S5), between November 2005 and October 2007, these detectors accumulated one year of triple coincident data while operating at their designed sensitivity. In this paper, we describe the calibration of the instruments in the S5 data set, including measurement techniques and uncertainty estimation.United States. National Aeronautics and Space AdministrationCarnegie TrustLeverhulme TrustDavid & Lucile Packard FoundationResearch CorporationAlfred P. Sloan Foundatio

Interlaboratory round robin on cantilever calibration for AFM force spectroscopy.

Item does not contain fulltextSingle-molecule force spectroscopy studies performed by Atomic Force Microscopes (AFMs) strongly rely on accurately determined cantilever spring constants. Hence, to calibrate cantilevers, a reliable calibration protocol is essential. Although the thermal noise method and the direct Sader method are frequently used for cantilever calibration, there is no consensus on the optimal calibration of soft and V-shaped cantilevers, especially those used in force spectroscopy. Therefore, in this study we aimed at establishing a commonly accepted approach to accurately calibrate compliant and V-shaped cantilevers. In a round robin experiment involving eight different laboratories we compared the thermal noise and the Sader method on ten commercial and custom-built AFMs. We found that spring constants of both rectangular and V-shaped cantilevers can accurately be determined with both methods, although the Sader method proved to be superior. Furthermore, we observed that simultaneous application of both methods on an AFM proved an accurate consistency check of the instrument and thus provides optimal and highly reproducible calibration. To illustrate the importance of optimal calibration, we show that for biological force spectroscopy studies, an erroneously calibrated cantilever can significantly affect the derived (bio)physical parameters. Taken together, our findings demonstrated that with the pre-established protocol described reliable spring constants can be obtained for different types of cantilevers.1 december 201

A record of soil loss from Butrint, southern Albania, using mineral magnetism indicators and charcoal (AD 450 to 1200).

Mineral magnetic and charcoal analyses were carried out on two sections 0.6 km apart on the Vrina Plain at Shën Dëlli, a suburb of Roman Butrint (ancient Buthrotum), southern Albania. Using a chronology developed by archaeomagnetic dating, the two sections postdate Roman archaeological structures on the site, providing a sediment record between c. ad 450 and 1200. Environmental magnetic data were analysed using cluster analysis to interpret a consistent stratigraphic development between the two sections. Above the archaeo logical remains on the western side of the Shën Dëli settlement, marsh clay sedimentation started ad 450–500, contemporaneous with evidence of site occupation. Anthropogenic activity is evident from the high macro-charcoal content, which declines at ad 750–800, and may mark the end of settlement in the vicinity. Both sections show similar sedimentation rates which, when extrapolated, suggest that marsh growth to the present day levels would have been completed between about ad 1500 and 1600. From about ad 750 to 850 sedimentation continued consistently across the site, with low microcharcoal input, but an increasingly important pres ence of magnetic minerals, including superparamagnetic magnetite, associated with top soil input. Between ad 1050 and 1200 the input from magnetically enhanced topsoil had increased tenfold over 300 years earlier, indicating that soil erosion was a major sediment source. This marked increase in soil loss could be due either to different land-management practices or to local deforestation. Whether this change in topsoil loss is linked to climatic changes associated with the beginning of the ‘Mediaeval Warm Period’ (c. ad 1000–1400) needs further investigation