GODIVA2: interactive visualization of environmental data on the Web

GODIVA2 is a dynamic website that provides visual access to several terabytes of physically distributed, four-dimensional environmental data. It allows users to explore large datasets interactively without the need to install new software or download and understand complex data. Through the use of open international standards, GODIVA2 maintains a high level of interoperability with third-party systems, allowing diverse datasets to be mutually compared. Scientists can use the system to search for features in large datasets and to diagnose the output from numerical simulations and data processing algorithms. Data providers around Europe have adopted GODIVA2 as an INSPIRE-compliant dynamic quick-view system for providing visual access to their data

Arp2/3 complex activity in filopodia of spreading cells

Background Cells use filopodia to explore their environment and to form new adhesion contacts for motility and spreading. The Arp2/3 complex has been implicated in lamellipodial actin assembly as a major nucleator of new actin filaments in branched networks. The interplay between filopodial and lamellipodial protrusions is an area of much interest as it is thought to be a key determinant of how cells make motility choices. Results We find that Arp2/3 complex localises to dynamic puncta in filopodia as well as lamellipodia of spreading cells. Arp2/3 complex spots do not appear to depend on local adhesion or on microtubules for their localisation but their inclusion in filopodia or lamellipodia depends on the activity of the small GTPase Rac1. Arp2/3 complex spots in filopodia are capable of incorporating monomeric actin, suggesting the presence of available filament barbed ends for polymerisation. Arp2/3 complex in filopodia co-localises with lamellipodial proteins such as capping protein and cortactin. The dynamics of Arp2/3 complex puncta suggests that they are moving bi-directionally along the length of filopodia and that they may be regions of lamellipodial activity within the filopodia. Conclusion We suggest that filopodia of spreading cells have regions of lamellipodial activity and that this activity affects the morphology and movement of filopodia. Our work has implications for how we understand the interplay between lamellipodia and filopodia and for how actin networks are generated spatially in cells

Cold spray surface patterning of aluminum on aluminum, silicon, glass, and printed circuit board substrates

17 USC 105 interim-entered record; under review.The aim of the present study is to investigate the feasibility and the criteria of using the cold spray technique for surface patterning to create two-dimensional surface features on various substrates. Metal meshes (16, 45, 170, 200, 400, and 5/16″) were used as screens for surface patterning in this investigation; fabricated features were characterized with optical microscope, scanning electron microscope, and optical profilometer. Processing parameters like mesh size, standoff distance, gun traverse speed, and number of spray passes were examined to study their influence to the morphology of the fabricated features. Two-dimensional aluminum features were successfully fabricated on aluminum, soda-lime glass, silicon wafer, and the copper foil-layer of printed circuit board. The smallest feature created with −45 to +5 μm aluminum feedstock powders, has an average size of 67.4 μm. It was determined that the pore size of a mesh needs to be at least 3.3 times bigger than the average size of feedstock powders in order to create features successfully. To estimate the probability of feedstock powders passing through a mesh and simulate the topography of the fabricated features, a Monte Carlo simulation incorporating the particle size distribution and the geometries of meshes was developed. With the capability of creating features on diverse substrates, the cold spray surface patterning technique shows promising potential to create heterogeneous two-dimensional functional features or devices at micron-sized with high efficiency.This work was funded by the Department of Mechanical and Aerospace Engineering of the Naval Postgraduate School

Phase sensitivity at the Heisenberg limit in an SU(1,1) interferometer via parity detection

We theoretically investigate the phase sensitivity with parity detection on an SU(1,1) interferometer with a coherent state combined with a squeezed vacuum state. This interferometer is formed with two parametric amplifiers for beam splitting and recombination instead of beam splitters. We show that the sensitivity of estimation phase approaches Heisenberg limit and give the corresponding optimal condition. Moreover, we derive the quantum Cram\'er-Rao bound of the SU(1,1) interferometer.Comment: 9 pages, 2 figures, 3 table