Abstract: A method of evaluating the immunosuppressive activity of a compound including contacting the compound with calcineurin and determining the ability of the compound to bind to the calcineurin. The ability to bind to the calcineurin is positively correlated to the immunosuppressive activity of the compound.

Abstract: An HTSC material epitaxially deposited on a YSZ buffer layer on a surface of a monocrystalline silicon substrate has a zero resistance transition temperature of at least 85.degree. K., a transition width (10-90%) of no more than 1.0.degree. K., a resistivity at 300.degree. K. of no more than 300 micro-ohms-centimeter and a resistivity ratio (at 300.degree. K./100.degree. K.) of 3.0.+-. 0.2. The surface of the silicon substrate is cleaned using a spin-etch process to produce an atomically clean surface terminated with an atomic layer of an element such as hydrogen with does not react with silicon. The substrate can be moved to a deposition chamber without contamination. The hydrogen is evaporated in the chamber, and then YSZ is epitaxially deposited preferably by laser ablation. Thereafter, the HTSC material, such as YBCO, is epitaxially deposited preferably by laser ablation. The structure is then cooled in an atmosphere of oxygen.

Abstract: A supersonic, direct-current arcjet is designed for expansion into low pressure, the arcjet operates as mixtures of hydrogen and argon to convert molecular hydrogen to atomic hydrogen and direct the atomic hydrogen to a substrate surface. A hydrocarbon (methane or acetylene) is introduced in the arcjet plume where it is converted to hydrocarbon precursors and is directed to the substrate surface where it combines with the atomic hydrogen to produce a diamond film.

Abstract: A monolithic crystalline material for quasi-phase-matching is described. The material includes a plurality of wafers of an odd multiple of coherence length thickness, having their faces bonded together by diffusion bonding. The wafers are oriented relative to one another to alternate their signs of nonlinear susceptibility. The invention also includes a method for producing optical radiation of a selected frequency by quasi-phase-matching, several specific methods and materials based on the discovery responsible for the invention, a generator for radiation of 60 THZ frequency of significant power, and a method of fabricating the material.

Abstract: An interferometer used as a rotation sensor is constructed using a strand of optical fiber, a portion of which is formed into a sensing loop. A pair of light waves are caused to counterpropagate in the sensing loop and are combined to form an optical output signal that has an intensity that varies in accordance with the difference in the phases of the two counterpropagating light waves. A phase modulator is positioned on the optical fiber in the sensing loop at a location such that the two counterpropagating light waves are modulated approximately 180 degrees out of phase. The time-varying phase modulation causes a time-varying phase difference that is combined with a rotationally-induced Sagnac effect phase to provide a total phase difference that is detected by a photodetector. The photodetector provides an electrical output signal that is processed to determine the Sagnac phase difference. The rotation rate is then calculated from the Sagnac phase difference.

Abstract: A nonlinear impedance transformer comprising a plurality of scaled L-C sections. The first section has its inductance and capacitance values selected to establish a characteristic impedance approximately equal to the output impedance of the local oscillator. The last section has its inductance and capacitance values selected to establish an output impedance which substantially matches the input impedance of whatever device to which the nonlinear impedance transformer is coupled. The impedance of each section is scaled logarithmically between the values of the input and output impedances. An FET driver can be integrated on the same substrate as integrated versions of the nonlinear impedance transformer. In such a case, the input impedance of the first section is set to the output impedance of the FET, i.e., about 10 ohms.

Abstract: A method for constructing an image of a macromolecular crystal includes steps of providing an envelope which defines the region of a unit cell occupied by the macromolecule; distributing a collection of scattering bodies within the envelope; condensing the collection of scattering bodies to an arrangement that maximizes the correlation between the diffraction pattern of the crystal and a pattern of Fourier amplitudes for the collection of scattering bodies; determining the phase associated with at least one of the Fourier amplitudes of the condensed collection of scattering bodies; calculating an electron density distribution of the crystal from the phase information; and defining an image of the macromolecule in the electron density distribution.

Abstract: A quasi-periodic signal is sampled at a specified rate, and then a predicted value of the signal is computed from a set of 2M+1 time lagged signal samples. The time lagged samples are centered in time at an integer multiple P of the signal's sampling period T.sub.s, where P.multidot.T.sub.s is approximately one period of the input signal. The predicted signal value is computed by multiplying each of the 2M+1 time lagged samples by a corresponding predictor coefficient c(i) and then summing the resulting products. The predicted signal value is subtracted from the actual signal value to obtain an error signal .epsilon.. During each successive sampling period, the predictor coefficients are updated by adjusting the previously computed predictor coefficients by an amount proportional to the error .epsilon. multiplied by each of the 2M+1 time lagged signal values. Using the updated coefficient values, a phase delay is computed, and then the signal's period is computed as the sum of phase delay and P.multidot.T.

Abstract: An in-vivo correction method for the non-linear, shape dependent spatial distortion in MR images due to magnetic field inhomogeneity including inhomogeneity due to susceptibility variations is disclosed. Geometric distortion at the air/tissue and tissue/bone interfaces before and after the correction is quantified using a phantom. The results are also compared to the "distortion-free" CT images of the same phantom. Magnetic susceptibility of cortical cattle bone was measured using a SQUID magnetometer and found to be -8.86 ppm which is quite similar to that of tissue (-9 ppm). The distortion at the bone/tissue boundary was negligible while that at the air/tissue boundary created displacements of about 2.0 mm with a1.5T main magnetic field and a 3.13 mT/m gradient field, a significant value if MR images are used to localize targets with the high accuracy expected for stereotaxic surgery. The correction method reduces the errors to at least the same level of accuracy as CT.

Abstract: A Brillouin fiber optic gyroscope having a feedback system which monitors the difference between counterpropagating Brillouin intensities and utilizes this difference in the form of a correction signal to control one of the circulating pump intensities so as to equalize the circulating pump intensities. The Brillouin fiber optic gyroscope further includes a second feedback system which detects electrical signals proportional to the phase-modulated, counterpropagating intensities in the gyroscope, and utilizes a combination of the electrical signals as an error signal to stabilize the resonant cavity at a length substantially equal to a length midway between the resonant lengths of the counterpropagating pump signals. The Brillouin fiber optic gyroscope of the present invention also provides a dynamic range of the gyroscope rotation rate that is twice the dynamic range of existing gyroscopes.

Abstract: A modulator adapted to be acoustically coupled to an optical fiber for applying acoustic waves across the fiber at a spatial and phase angle with respect to one another to compress and decompress the optical fiber at said spatial angle responsive to an electrical signal whereby to modulate the polarization state of an optical wave travelling past said modulator. An optical communication system in which light waves are transmitted from a transmitting end to a receiving end and whose polarization is modulated by an acoustic modulator responsive to an input signal and the output signal is demodulated to recover the signal.

Abstract: A microminiature cantilever structure is provided having a cantilever arm with a piezoresistive resistor embedded in at least the fixed end of the cantilever arm. Deflection of the free end of the cantilever arm produces stress in the base of the cantilever. That stress changes the piezoresistive resistor's resistance at the base of the cantilever in proportion to the cantilever arm's deflection. Resistance measuring apparatus is coupled to the piezoresistive resistor to measure its resistance and to generate a signal corresponding to the cantilever arm's deflection. The microminiature cantilever is formed on a semiconductor substrate. A portion of the free end of the cantilever arm is doped to form an electrically separate U-shaped piezoresistive resistor. The U-shaped resistor has two legs oriented parallel to an axis of the semiconductor substrate having a non-zero piezoresistive coefficient.

Abstract: A method of assessing a cell's susceptibility to cell-damaging energy, such as ionizing radiation and heat, is disclosed. The method is based on measurable changes in voltage-dependent potassium channel currents in the cell in response to the energy. Also disclosed is a method for screening drugs which are effective to sensitize a cell to cell-damaging radiation.

Abstract: A workpiece of a fiber-containing composite material is formed in a kinematically admissible manner by applying a tension loading to the workpiece in a transverse direction and passing the workpiece in the transverse direction through apparatus having a bending roller extending in the longitudinal direction over substantially the entire length of the workpiece. The workpiece is formed over the bending roller by introducing a net bending deformation into the workpiece and progressively propagating the bend transversely through the workpiece as the workpiece is moved in the transverse direction. The transverse laminar length of the workpiece remains substantially unchanged during the forming process. Preferably, the workpiece is contained within a vacuum bag during the forming operation.

Abstract: A method and apparatus for increasing the capacity of wireless broadcast communications system from a central studio to a plurality of users in a service area is disclosed. Given a source signal whose high information rate exceeds the practical information carrying capacity of the available broadcast channel bandwidth, the invention increases the effective capacity of the broadcast system to effectively communicate such a source signal. The high-rate signal is split into several low-rate signals such that each can be accommodated within the allocated bandwidth. These low-rate signals are transmitted from spatially separated transmitters, all radiating into the service area in the same frequency channel. Each receiver uses a plurality of antennas to receive these multiple cochannel signals that arrive from different directions-of-arrival. The receiver exploits the directions-of-arrival differences of these cochannel signals to separate them into the individually transmitted signals.

Abstract: A voltage alternating between a high value and a low value is applied across a separation capillary in an electrophoretic system and electrochemical detection is performed only during time periods when a low voltage or no voltage is applied to the tube to improve the sensitivity of detection.

Abstract: A dosimeter for use in mixed radiation fields is disclosed. The dosimeter consisting of a single element may be used in a photon-neutron field if the energies of the photons and neutrons are known. In a mixed photon-neutron-beta radiation field of unknown energies, a detector having four elements is sufficient to provide an estimate of the exposure. The dosimeter makes use of the high temperature readout from a 6Li doped LiF thermoluminescent detector to provide an estimate of both the neutron and photon exposures.

Abstract: Novel methods and microorganisms are provided, where novel genetic mammalian cell invasive capability is imparted to a microorganism by the introduction of an exogenous inv gene. The resulting organisms are then capable of binding to mammalian cells and are transferred to the cytoplasm. Other novel genetic capabilities may be imparted to the unicellular microorganism, which may serve as a vaccine for one or more pathogens or may introduce genetic capabilities or foreign molecules into a mammalian host cell. The sequences may be used for an in vitro screen for pathogenicity.

Abstract: An interferometer used as a rotation sensor is constructed using a strand of optical fiber, a portion of which is formed into a sensing loop. A pair of light waves are caused to counterpropagate in the sensing loop and are combined to form an optical output signal that has an intensity that varies in accordance with the difference in the phases of the two counterpropagating light waves. A phase modulator is positioned on the optical fiber in the sensing loop at a location such that the two counterpropagating light waves are modulated approximately 180 degrees out of phase. The time-varying phase modulation causes a time-varying phase difference that is combined with a rotationally-induced Sagnac effect phase to provide a total phase difference that is detected by a photodetector. The photodetector provides an electrical output signal this is processed to determine the Sagnac phase difference. The rotation rate is then calculated from the Sagnac phase difference.

Abstract: The restoration of a band-limited signal which has undergone amplitude clipping is viewed as recovery from signal drop-outs (missing samples over an interval of time), with the extrapolated signal constrained to lie outside the clipping interval during the drop out. If the signal is oversampled, and the clipping threshold moderate, a unique reconstruction may result from application of signal matching and bandwidth constraints. More generally, however, candidate reconstructions are seen to lie on or inside a polyhedron in the space of sampled signals. In contrast to the case of extrapolation through missing samples, upper and lower limits typically can be placed on the reconstructed signal at every sample point. In light of this finding, methods for choosing a unique reconstruction are achieved. The use of inequality constraints allows practical restoration of clipped signals.