Abstract: A quick screening method for microbial strains includes the steps of: feeding a carrier worm with Styrofoam for a plurality of days; and sampling a digestive system of the carrier worm and placing the sampled digestive system of the carrier worm into a culture medium. The digestive system of the carrier worm includes at least one Styrofoam degrading microbial strain. The culture medium includes an emulsion formed by dissolving the Styrofoam with chloroform and adding a surfactant to the dissolved Styrofoam. A culture medium for fast culturing of the at least one microbial strain is also provided.

Abstract: A quick screening method for microbial strains includes the steps of: feeding a carrier worm with Styrofoam for a plurality of days; and sampling a digestive system of the carrier worm and placing the sampled digestive system of the carrier worm into a culture medium. The digestive system of the carrier worm includes at least one Styrofoam degrading microbial strain. The culture medium includes an emulsion formed by dissolving the Styrofoam with chloroform and adding a surfactant to the dissolved Styrofoam. A culture medium for fast culturing of the at least one microbial strain is also provided.

Abstract: An integrated circuit preamplifier amplifies an input signal comprising first and second differential input signals to provide an amplified output signal comprising first and second differential output signals. A biasing circuit of the preamplifier provides a bias current. An open-loop differential amplifier of the preamplifier is coupled to the biasing circuit. The differential amplifier includes a differential amplifier pair having first and second differential amplifying transistors, which are coupled at respective gate terminals to the first and second differential input signals. Each of the amplifying transistors are coupled in open-loop configuration at a drain terminal to a respective load resistor coupled to ground, and the source terminals of the amplifying transistors are coupled together to receive the bias current. The first and second differential output signals are formed across the respective first and second load resistors.

Abstract: A method and apparatus for adjusting the resistance across a slave transistor to follow a master resistor network are disclosed. A tuning circuit is disclosed which is used to control the effective resistance of a slave transistor for use in high speed integrated automatic gain control, equalizer, filter or equivalent types of circuits where low parasitic capacitance is desired. The invention provides a way to replace a resistor network and its associated high parasitic capacitance with an equivalent resistance having low parasitic capacitance. The invention replaces the resistor network, having large parasitic capacitance, with a slave transistor exhibiting an equivalent resistance, having low parasitic capacitance. An automatic tuning circuit containing a resistor network is located remotely to a circuit containing a slave transistor. The tuning circuit is then used to adjust the effective resistance of the slave transistor.

Abstract: An integrated circuit differential amplifier with a digitally controllable gain. In a preferred embodiment, the differential amplifier employs first and second transconductance (gm) amplifiers and a digital to analog converter (DAC). The first gm amplifier converts a differential input voltage into a differential output current and the second gm amplifier converts the differential output current into a differential output voltage. A digital input code is applied to the DAC to generate an analog output voltage that is applied to one of the gm amplifiers to control its transconductance to thereby control the gain of the differential amplifier. The second gm amplifier employs a pair of low impedance feedback paths between input/output terminals of opposite polarity. The gain of the differential amplifier is thus a function of the ratio of the transconductance of the first gm amplifier to that of the second gm amplifier.