Abstract: The present invention provides methods of post-transcriptional gene silencing which involve the use of a first dsRNA having substantial sequence identity to a target nucleic acid and a short, second dsRNA which inhibits dsRNA-mediated toxicity. These methods can be used to prevent or treat a disease or infection by silencing a gene associated with the disease or infection. The invention also provides methods for identifying nucleic acid sequences that modulate a detectable phenotype, including the function of a cell, the expression of a gene, or the biological activity of a target polypeptide.

Abstract: The invention features methods of analyzing the kinetics properties of transfection reactions. Also featured are methods for creating structural promoters which are effectively unregulated by enhancers and repressors. The structural promoters are significantly more active than the native promoter sequences upon which they are based.

Abstract: Conserved consensus sequences from known hepatitis B virus strains and known hepatitis C virus strains, which are useful in inhibiting the expression of the viruses in mammalian cells, are provided. These sequences are useful to silence the genes of HBV and HCV, thereby providing therapeutic utility against HBV and HCV viral infection in humans.

Abstract: The present invention provides methods of post-transcriptional gene silencing which involve the use of a first dsRNA having substantial sequence identity to a target nucleic acid and a short, second dsRNA which inhibits dsRNA-mediated toxicity. These methods can be used to prevent or treat a disease or infection by silencing a gene associated with the disease or infection. The invention also provides methods for identifying nucleic acid sequences that modulate a detectable phenotype, including the function of a cell, the expression of a gene, or the biological activity of a target polypeptide.

Abstract: Methods and constructs for selecting double-stranded RNA molecules capable of post-transcriptional gene silencing (PTGS) or RNA interference (RNAi); and methods of selecting targets susceptible to double-stranded RNA mediated PTGS or RNAi.

Abstract: A turnstile structure has a control head contained in a readily accessible head compartment assembly. The head compartment assembly contains the control head in a cavity within the assembly and the turnstile control assembly, e.g., turnstile arms, extend outwardly from the control head and away from the head compartment. The head compartment assembly is fastened to a turnstile structure main frame at two principle edges of the assembly. Along one of these principle edges, the head compartment assembly is hinged to the main frame. At the other principle edge, the head compartment assembly is releasably secured to the main frame. These connections can provide for access to the control head through either tilting the head compartment assembly upwardly to expose the assembly cavity, in one structural embodiment, or downwardly to expose the cavity in another structural embodiment.

Abstract: A cover for a pressure sensor for indicating cracks in a hollow aircraft blade, the sensor having a shaft carrying a radiation source, with the shaft sliding in a housing between a first position with the radiation source within the housing and a second position with the radiation source external of the housing, the cover including a sleeve for positioning around the sensor and having an open end for engaging a shoulder of the sensor and having a closed end spaced from the sensor when the open end is engaging the sensor shoulder, and a plunger slidably mounted in the closed end and movable between an outer position and an inner position, with the plunger out of engagement with the sensor shaft when in the outer position and engaging the sensor shaft when in the inner position to move the shaft into the sensor and reset the sensor, with the sleeve being of a material absorbing the radiation of the source.

Abstract: A tank content gauging system including a plurality of radiation sources and a radiation detector mounted at a fuel tank, with the radiation detector positioned for receiving radiation from the sources and for producing an output which is an electrical analog of the detected radiation, a register for storing the detector output, a telemetry-on-demand switching unit for starting and stopping the detector operation from a point distant from the tank, a transceiver for sending "on" and "off" commands to the switching unit and receiving telemetry data from the register, a computer having the telemetry data and reference data as inputs for producing an output representing the quantity of fuel in the tank, and a display for indicating the quantity of fuel in the tank.

Abstract: A system for indicating cracks in a hollow aircraft blade, such as a helicopter blade. A system wherein a pressure differential is maintained within the blade with respect to the ambient atmosphere and including a pressure sensor for mounting on the blade in communication with the interior of the blade and having a member which moves in response to pressure changes within the blade, a beta radiation source mounted on the member and disposed for radiation transmission to a detector, a beta radiation detector for mounting on a nonrotating portion of the aircraft for receiving radiation from the source, and circuitry having the output of the detector as an input and providing an output which varies as a function of the position of the pressure sensor member for indicating the pressure condition within the blade. An improved beta radiation detector housing which substantially eliminates detector sensitivity to radar transmissions while maintaining sensitivity to nuclear radiation in the beta range.

Abstract: Competitive assay procedure for determining the concentration of physiologically active haptens in which the hapten is bound to an immunogenic carrier and competes for binding sites on antibodies against the hapten. Actual concentration is determined by comparison with standard curves.

Abstract: An improved cuvette array for a centrifugal analyzer is disclosed. The array is conventionally formed from upper and lower discs of flexible thermoplastic material, in which the lower disc is formed with a plurality of compartments circumferentially spaced about a first central hub, and the upper disc is bonded to the outer periphery of the lower disc and closes an outer peripheral portion of the compartments. The array is improved by forming the upper disc with a central portion that includes a second central hub positioned above the first central hub, together with an intermediate web that bridges the second central hub to the outer peripheral portion of the upper disc so as to close off the inner peripheral portion of the compartments. The intermediate web portion may be joined to the outer peripheral portion of the upper disc by a tearible score line to permit the central portion of the upper disc to be entirely removed.

Abstract: A reagent suitable for .alpha.-amylase determinations. The reagent contains a modified, blocked amylaceous polysaccharide substrate, e.g., starch glyolate, an exating by amylose, a buffer and an enzymatic glucose measuring system. The glycolate substrate is selected such that the ratio of methylated glucose to glucose is between 1:4 to 1:16. The system permits an impid assay in a single vid within 7 minutes and can be automated.

Abstract: A clinical analyzer that is microprocessor controlled is disclosed. A shuttle carries a plurality of cuvettes containing liquids to be spectrophotometrically analyzed by a single beam spectrophotometer. The shuttle moves the cuvettes past the spectrophotometer in a plurality of cycles to complete a given test. At the beginning of a test, spectrophotometer lamp energization is controlled to achieve a predetermined spectrophotometer output for a reference filter. The remaining filters are then positioned one-by-one, and amplifier gain is adjusted to achieve optimum spectrophotometer output for each filter. The gain associated with each filter is stored by the microprocessor, and thereafter during the test, when each filter is used, the stored gain associated with that microprocessor is utilized in the amplifier circuitry. Additionally, at the beginning of each cycle of shuttle movement, an air calibration reading is taken, to be used by the microprocessor in determining absorbance.

Abstract: An assembly for loading and dispensing varying amounts of fluid from multiple syringes is disclosed. A body member having spaced-apart surfaces A.sub.o and B.sub.o coacts with a handle member having spaced-apart surfaces A.sub.1 and B.sub.1 (A.sub.1 and B.sub.1 are either fixedly spaced or variably spaced) parallel to the surfaces A.sub.o and B.sub.o. The handle member is mounted for relative reciprocal movement with respect to the body member in a direction D.sub.o the same as a vector perpendicular to the surfaces A.sub.o and B.sub.o. A plurality of syringe actuators each associated with an individual one of the syringes is included, and they are mounted for relative movement with respect to the body member. Each syringe actuator has actuating surfaces for respective contact with the surfaces A.sub.o and B.sub.o on the body member and A.sub.1 and B.sub.1 on the handle member.

Abstract: A system for the detection of a biological analyte of interest is disclosed which comprises a microencapsulated fluorescer material which has been conjugated to an immunological specie specific to the biological analyte of interest, a means of disrupting the capsule containing the fluorescer and an energy source other than electro-magnetic radiation which is capable of activating the fluorescer.

Abstract: A valve structure in which a valve member moves into and out of contact with first and second valve seating areas, the valve member contacting the seating areas with different forces. The movable valve member is comprised of block members coupled together so that a change in their relative longitudinal positions produces a corresponding change in their relative transverse positions. A stem member moves the block members to spaced longitudinal positions and produces different longitudinal separating forces between the block member in these positions thereby to urge one of the block members in a transverse direction with different forces against the valve seating areas. The application of forces directly through block members and indirectly through springs is employed to provide different valve seating forces. Block members for valve port blocking and valve port opening are utilized. A shock absorbing structure incorporating a movable spring holder is also utilized.

Abstract: Apparatus for determining weight of a container moving along a path past a weighing zone with radioactive source and detector mounted on opposite sides of the path for directing a radiation beam through the container passing through the weighing zone. Counters for counting radiation detector output pulses and reference timing pulses, with position sensors providing a gating for the counters so as to count when a container is moving past the radiation beam. The quotient of the two counts provides a measure of weight of a container.

Abstract: A system for automatically processing liquids in open-ended containers. The containers are moved past a plurality of operating stations that carry out the following operations: washing, reagent-adding, incubation, detection, and storage. The operating stations for washing and reagent-addition include vertically and horizontally movable assemblies for operating upon the containers. The containers are carried in groups in individual carrying blocks which are moved throughout the system.