Abstract: The present invention provides an isolated nucleic acid covalently linked to a photolabile caging group which reversibly prevents expression of the nucleic acid. The present invention further provides a method of selectively expressing a nucleic acid in a cell, comprising: a) covalently linking the nucleic acid to a photolabile caging group which reversibly prevents expression of the nucleic acid; b) introducing the nucleic acid of step (a) into the cell; and c) exposing the cell of step (b) to light, whereby exposure to the light unlinks the nucleic acid and the caging group and the nucleic acid is selectively expressed in the cell.

Abstract: A device for effecting local reduction of sea wave amplitude includes a grid plate adapted to be supported in the sea at a predetermined depth ensuring that the grid plate remains submerged below the trough of the highest wave expected to be encountered in use of the wave reduction device. The grid plate member includes a plurality of interconnected elongate supporting members hingedly supporting flapper valve plates which are operable between substantially opened and closed positions, each flapper walve in its opened position permitting sea water to flow substantially unimpeded through the flapper valve and in its closed position substantially blocking the flow of sea water through the flapper valve.

Abstract: A plurality of blades extend radially from a hub which is rotated by a motor about a drive axis. Each blade has a root which is rotatably connected to the hub so that it can be independently twisted to vary the pitch thereof relative to the drive axis. A plurality of electromagnets are annularly positioned adjacent the hub so that permanent magnets connected to the roots of corresponding blades can be attracted and/or repelled to induce twisting motion in the blades as the hub rotates about its drive axis. A control circuit receives input commands for a manual control device and causes predetermined electrical signals to be applied to the electromagnets for simultaneously varying the pitch of the blades. The pitch of the blades can be varied cyclically and collectively in accordance with any real continuous function, and not just sinusoidally as in the case of prior mechanical linkages employing swash plates.

Abstract: A submarine well drilling and geological exploration station includes an inner pressure hull specially configured for submerged drilling and exploration and an outer fairing hull of conventional submarine design. The pressure hull is divided by an air lock into an atmospheric pressure chamber and a superatmospheric pressure chamber. Ballast tanks are arranged so that the station may be rotated from a horizontal in-transit orientation to a vertical drilling and exploration orientation. The superatmospheric chamber permits exploration and drilling operations therein in the vertical orientation. A tandem propeller system is used to stabilize the station in position while in the vertical orientation and to propel the station from location to location while submerged in the horizontal orientation.

Abstract: An apparatus for damping vertical movement of a semi-submersible vessel having a small waterplane area, whose buoyancy is provided substantially completely by submerged pontoon means and which includes at least one submerged damper plate having valves or similar flow controllers therein for providing substantially greater resistance to upward movement of the plate than downward movement. The damper plate is supported deep beneath the semi-submersible vessel by flexible, tensioned support elements such as chains or cables, at a depth beneath the water surface in the semi-submerged condition of the vessel, at which depth the amplitude of subsurface wave motion is less than the maximum heave amplitude which would be experienced by the semi-submersible vessel alone under identical sea conditions. The area of the damper plate is several times larger than the waterplane area of the vessel.

Abstract: The disclosed device provides a normal minimum flush cycle for water closets with the ability to override the short cycle to cause a larger water volume flush cycle. The conventional tank flapper dump valve is modified so as to retain no buoyancy during the flush cycle and a positively buoyant member is adjustably fixed on the valve operating chain an appropriate distance from the valve. When the operating handle is actuated, the added buoyancy holds the valve open while the water level in the tank falls until the added buoyancy member surfaces at which time the valve closes and the tank refills normally. Short cycle override is accomplished by merely holding the handle in the actuated position allowing a greater portion of the water in the reservoir to pass.