Electronic position indicator for latching solenoid valves

Electronic circuit connected to solenoid valve coils visually indicates the position of the valve stem. Transient suppression is provided to prevent damaging voltage spikes

Spatial organization of visuomotor reflexes in Drosophila

In most animals, the visual system plays a central role in locomotor guidance. Here, we examined the functional organization of visuomotor reflexes in the fruit fly, Drosophila, using an electronic flight simulator. Flies exhibit powerful avoidance responses to visual expansion centered laterally. The amplitude of these expansion responses is three times larger than those generated by image rotation. Avoidance of a laterally positioned focus of expansion emerges from an inversion of the optomotor response when motion is restricted to the rear visual hemisphere. Furthermore, motion restricted to rear quarter-fields elicits turning responses that are independent of the direction of image motion about the animal's yaw axis. The spatial heterogeneity of visuomotor responses explains a seemingly peculiar behavior in which flies robustly fixate the contracting pole of a translating flow field

German Romanticism

The German romantic movement was the result of defective culture, of bodily and mental derangement, of spiritual and nervous disorder. It is a work of degeneration, deformation, and disease. And it bears on its front the stigmata of its infirmities - absurdity, folly, inanity, and confusion. There is Hardenberg, the pattern of the school, who falls in love with a chit of thirteen and at her death a year or so later dedicates himself to the grave, an unblemished sacrifice of love, unblighted by sickness, violence, or sorrow, the cheerful victim of his own regret. In the meanwhile he begins a new era and dates his note-books from the epoch of her decease

Stylolites in the Burlington Limestone near Kinderhook, Illinois

Weil developed stylolites showing a peculiar relationship to chert occur in the Burlington limestone north of Kinderhook, Illinois. Specimens were studied by the preparation of insoluble residues of the limestone and clay cap, and by making thin sections of the chert nodules. Stockdale\u27s conclusion of origin by solution in an indurated rock is ascribed to for the stylolites in question because, (1) crinoid stems are fluted along the sides of prongs the same as the mass of the rock, (2) the suite of minerals occurring in the clay cap\u27\u27 represents nearly a true average of the suites of minerals from the residues above and below the stylolite, (3) the chert in every case examined was prior to the stylolite formation as shown by fluting along the sides and pitting of upper and lower surfaces, and (4) the presence of systems of subsidiary stylolites which crosscut the prongs of the earlier and larger system. The thickness of the clay cap has little relation to the amount of material removed, as it varied up to 75 per cent soluble

LensPerfect: Gravitational Lens Massmap Reconstructions Yielding Exact Reproduction of All Multiple Images

We present a new approach to gravitational lens massmap reconstruction. Our massmap solutions perfectly reproduce the positions, fluxes, and shears of all multiple images. And each massmap accurately recovers the underlying mass distribution to a resolution limited by the number of multiple images detected. We demonstrate our technique given a mock galaxy cluster similar to Abell 1689 which gravitationally lenses 19 mock background galaxies to produce 93 multiple images. We also explore cases in which far fewer multiple images are observed, such as four multiple images of a single galaxy. Massmap solutions are never unique, and our method makes it possible to explore an extremely flexible range of physical (and unphysical) solutions, all of which perfectly reproduce the data given. Each reconfiguration of the source galaxies produces a new massmap solution. An optimization routine is provided to find those source positions (and redshifts, within uncertainties) which produce the "most physical" massmap solution, according to a new figure of merit developed here. Our method imposes no assumptions about the slope of the radial profile nor mass following light. But unlike "non-parametric" grid-based methods, the number of free parameters we solve for is only as many as the number of observable constraints (or slightly greater if fluxes are constrained). For each set of source positions and redshifts, massmap solutions are obtained "instantly" via direct matrix inversion by smoothly interpolating the deflection field using a recently developed mathematical technique. Our LensPerfect software is straightforward and easy to use and is made publicly available via our website.Comment: 17 pages, 18 figures, accepted by ApJ. Software and full-color version of paper available at http://www.its.caltech.edu/~coe/LensPerfect