Abstract: Until recently, risk models have been built using low frequency data, such as weekly or monthly data. This approach has resulted in a necessary compromise between model stability for which one needs a long history of data, and model responsiveness, for which, the shorter the history, the better. Stability plus responsiveness can be achieved if one uses daily data, which allows for a large number of observations to be used in model estimation without using long out-of-date data. Daily data have other problems, however, as the differing closing times of markets worldwide may induce spurious relationships across model factors. In particular, correlations between markets may appear lower than they truly are due to a market lag To address such issues, a stable, daily data-based factor risk model is described which takes account of the differing market closing times and corrects the model factor correlations and specific returns accordingly.

Abstract: Fast and simple method of detecting the presence of chloramphenicol, a harmful compound if present in food products. The method makes use of a mutant chloramphenicol acetyltransferase (CAT) and a fluorophore-linked chloramphenicol in a system where chloramphenicol and the fluorophore-linked chloramphenicol competes for the active site of the mutant CAT. Because the fluorophore-linked chloramphenicol reduces its fluorescence upon binding to the active site and vice versa increases its fluorescence upon being displaced from the active site by the presence of unmodified chloramphenicol in a sample, the increase of fluorescence caused by a testing sample indicates the presence of chloramphenicol.

Abstract: Fast and simple method of detecting the presence of chloramphenicol, a harmful compound if present in food products. The method makes use of a mutant chloramphenicol acetyltransferase (CAT) and a fluorophore-linked chloramphenicol in a system where chloramphenicol and the fluorophore-linked chloramphenicol competes for the active site of the mutant CAT. Because the fluorophore-linked chloramphenicol reduces its fluorescence upon binding to the active site and vice versa increases its fluorescence upon being displaced from the active site by the presence of unmodified chloramphenicol in a sample, the increase of fluorescence caused by a testing sample indicates the presence of chloramphenicol.

Abstract: A plant extract comprising one or more statins and being substantially free of polar compounds that affect pharmacokinetics of a drug in a subject is provided. Also provided is a method of preparing an extract comprising the step of removing polar compounds that affect pharmacokinetics of a drug in a subject from a plant material containing one or more statins.

Abstract: A junction is made between a first microfluidic substrate (12) having an elongate component (303) protruding from it and a second microfluidic substrate (22) having a corresponding conduit (261). Each of the substrates has a pair of alignment features, for example planar orthogonal surfaces (13, 15; 23, 25) or grooves (141, 151; 241, 251) in opposite sides of the substrate. The substrates are placed on an alignment jig 6 having location features (63, 65) corresponding to the alignment features. The elongate component can be surrounded by a compressible gasket 40). The substrates are pushed towards each other so that the elongate component enters the conduit and the gasket, if any, is compressed. A fluid-tight junction results so long as the substrates are maintained in the necessary position, either by permanent means, or, if a junction which can be disassembled is needed, by maintaining pressure between the substrates.

Abstract: Systems and apparatus for converting an input current signal into two or more output voltage signals on an integrated circuit. In one aspect, an integrated circuit includes a first trans-impedance amplifier that includes a first cascode amplifier; and a second trans-impedance amplifier that includes a second cascode amplifier, the second cascode amplifier and the first cascode amplifier sharing an input transistive element; where the first cascode amplifier is coupled to one or more first switches that disable the first trans-impedance amplifier, the second cascode amplifier is coupled to one or more second switches that disable the second trans-impedance amplifier, and control logic coupled to the one or more first switches and the one or more second switches disables at least one of the first trans-impedance amplifier or the second trans-impedance amplifier.

Abstract: A junction is made between a first microfluidic substrate (12) having an elongate component (303) protruding from it and a second microfluidic substrate (22) having a corresponding conduit (261). Each of the substrates has a pair of alignment features, for example planar orthogonal surfaces (13, 15; 23, 25) or grooves (141, 151; 241, 251) in opposite sides of the substrate. The substrates are placed on an alignment jig 6 having location features (63, 65) corresponding to the alignment features. The elongate component can be surrounded by a compressible gasket 40). The substrates are pushed towards each other so that the elongate component enters the conduit and the gasket, if any, is compressed. A fluid-tight junction results so long as the substrates are maintained in the necessary position, either by permanent means, or, if a junction which can be disassembled is needed, by maintaining pressure between the substrates.

Abstract: A junction is made between a first microfluidic substrate (12) having an elongate component (303) protruding from it and a second microfluidic substrate (22) having a corresponding conduit (261). Each of the substrates has a pair of alignment features, for example planar orthogonal surfaces (13,15; 23,25) or grooves (141,151; 241, 251) in opposite sides of the substrate. The substrates are placed on an alignment jig 6 having location features (63, 65) corresponding to the alignment features. The elongate component can be surrounded by a compressible gasket 40). The substrates are pushed towards each other so that the elongate component enters the conduit and the gasket, if any, is compressed. A fluid-tight junction results so long as the substrates are maintained in the necessary position, either by permanent means, or, if a junction which can be disassembled is needed, by maintaining pressure between the substrates.

Abstract: Systems and apparatus for converting an input current signal into two or more output voltage signals on an integrated circuit. In one aspect, an integrated circuit includes a first trans-impedance amplifier that includes a first cascode amplifier; and a second trans-impedance amplifier that includes a second cascode amplifier, the second cascode amplifier and the first cascode amplifier sharing an input transistive element; where the first cascode amplifier is coupled to one or more first switches that disable the first trans-impedance amplifier, the second cascode amplifier is coupled to one or more second switches that disable the second trans-impedance amplifier, and control logic coupled to the one or more first switches and the one or more second switches disables at least one of the first trans-impedance amplifier or the second trans-impedance amplifier.

Abstract: A junction is made between a first microfluidic substrate (12) having an elongate component (303) protruding from it and a second microfluidic substrate (22) having a corresponding conduit (261). Each of the substrates has a pair of alignment features, for example planar orthogonal surfaces (13,15; 23,25) or grooves (141,151; 241, 251) in opposite sides of the substrate. The substrates are placed on an alignment jig 6 having location features (63, 65) corresponding to the alignment features. The elongate component can be surrounded by a compressible gasket 40). The substrates are pushed towards each other so that the elongate component enters the conduit and the gasket, if any, is compressed. A fluid-tight junction results so long as the substrates are maintained in the necessary position, either by permanent means, or, if a junction which can be disassembled is needed, by maintaining pressure between the substrates.

Abstract: A tool that can screen bacteria for ?-lactamases against a panel of various antibiotics is desirable. A biosensor incorporating an indicator molecule into ?-lactamases may achieve this purpose, but it requires that the attached indicator molecule must not impair the binding affinity of the protein to a great extent to provide a higher sensitivity. A modified ?-lactamases with a residue on the ?-loop or outside the ?-loop but close to the active site of ?-lactamase being replaced by a reactive residue is developed in this invention.

Abstract: Particles dispersed in a liquid are assembled in a configuration in which all the particles lie in the same plane, and the assembled particles are processed while in that configuration. The assembled particles can for example be simultaneously exposed to electromagnetic radiation which elicits from the particles a response which provides information about the particles. The particles can for example be cells, cell fragments, or analyte-bearing beads of the type conventionally analyzed in a cytometer.

Abstract: This invention provides a method of detecting pathogens comprising the steps of: (a) contacting a sufficient amount of biofunctional magnetic nanoparticles with an appropriate sample for an appropriate period of time to permit the formation of complexes between the pathogens in the sample and the nanoparticles; (b) using a magnetic field to aggregate said complexes; and (c) detecting said complexes. The method may further comprise the additional step of removing said complexes. The biofunctional magnetic nanoparticles are preferably a conjugate of vancomycin and FePt. The pathogens may be bacteria or viruses, and the sample may be a solid, liquid, or gas. Detection may involve conventional fluorescence assay, enzyme-linked immunosorbent assay (ELISA), optical microscope, electron microscope, or a combination thereof. The sensitivity of detection for the method is at least as low as 10 colony forming units (cfu) of the pathogens in one milliliter of solution within one hour.

Abstract: A tool that can screen bacteria for ?-lactamases against a panel of various antibiotics is desirable. A biosensor incorporating an indicator molecule into ?-lactamases may achieve this purpose, but it requires that the attached indicator molecule must not impair the binding affinity of the protein to a great extent to provide a higher sensitivity. A modified ?-lactamases with a residue on the ?-loop or outside the ?-loop but close to the active site of ?-lactamase being replaced by a reactive residue is developed in this invention.

Abstract: Particles dispersed in a liquid are assembled in a configuration in which all the particles lie in the same plane, and the assembled particles are processed while in that configuration. The assembled particles can for example be simultaneously exposed to electromagnetic radiation which elicits from the particles a response which provides information about the particles. The particles can for example be cells, cell fragments, or analyte-bearing beads of the type conventionally analyzed in a cytometer.

Abstract: The present invention relates to a crystal structure of G-quadruplexes and its use. The invention provides a crystal of an intramolecular G-quadruplex structure having a hexagonal space group P6, and unit cell dimensions a=b=56.7 and c=42.1; &agr;=&bgr;=90°, &ggr;=120° and a crystal of G-quadruplex having the three dimensional atomic coordinates of Table 1 or Table 2. These structures may be used in a computer-based method for the analysis of the interaction of a molecular structure with a G-quadruplex.

Abstract: A phase-locked loop (PLL) frequency synthesizer is described which incorporates a fractional pulse swallowing circuit. The fractional pulse swallowing circuit does not add or delete pulses but extends or shortens pulses by a fractional amount. This avoids large phase errors generated by a phase detector in the PLL. In the preferred embodiment, the PLL uses a voltage controlled oscillator (VCO) formed of a ring oscillator. The outputs of the stages of the ring oscillator are applied to input terminals of a multiplexer. The multiplexer is controlled at certain times to output a different tapped signal from the ring oscillator to effectively adjust the phase of the signal output from the multiplexer. By so controlling the multiplexer, fractional pulses are subtracted or added at intervals to either increase or decrease the average frequency of the signal output from the multiplexer. The output of the VCO is fed back to the input of a phase detector along with a reference frequency.

Abstract: An integrated circuit includes a semiconductor die and electronic circuitry elements formed therein. First and second internal power supply lines transmit first and second supply voltages to provide power for the circuitry elements. The die includes bypass circuitry to inhibit variations in the supply voltages. The bypass circuitry includes transconductance circuitry, characterized by a variable conductivity, having a first flow electrode coupled to the first supply line, a second flow electrode coupled to the second supply line, and a control electrode for controlling current flow between the flow electrodes. The conductivity of the transconductance circuitry varies in response to a voltage difference between the control electrode and the second flow electrode. Voltage amplifier circuitry has a first input terminal coupled to the first supply line and a second input terminal coupled to the second supply line.

Abstract: A differential amplifier provides a predetermined gain characteristic over a large range differential input voltage signals and operating temperatures. The differential amplifier receives a first differential input voltage signal at a pair of amplifier input terminals and outputs a differential output current signal at a pair of amplifier output terminals. First and second emitter-coupled transistors are connected to receive at their bases an amplifier core differential voltage signal, have their emitters coupled to receive first and second constant currents and coupled together by a load element. The first and second emitter follower transistors have their bases coupled to the amplifier input terminals to receive the first differential input voltage signal from the pair of amplifier input terminals.

Abstract: A voltage to current converter which exhibits a well-defined substantially exponential voltage-current characteristic. First and second input bipolar transistors of the voltage to current converter each have an emitter, a base, and a collector. The first and second input bipolar transistors are coupled at their emitters, and may be biased with a pre-determined constant current source, and they accept a selectable differential input voltage at their bases. A reference current source is connected to the collector of the first input bipolar transistor, and all output current source is connected to the collector of the second input bipolar transistor. A feedback element, having a gain, is connected between the coupled emitters and the collector of the first input bipolar transistor. The feedback element senses a voltage at the collector of the first input bipolar transistor and regulates a voltage at the coupled emitters to maintain a constant current through said first input bipolar transistor.