Abstract: A link adaptive orthogonal frequency-division multiplexed (OFDM) ultrasonic physical layer is provided that is capable of high data rate communication through metallic structures. The use of an adaptive OFDM subcarrier-based modulation technique mitigates the effects of severe frequency selective fading of the through-metal communication link and improves spectral efficiency by exploiting the slow-varying nature of the channel. To address the potential ill effects of peak-to-average power ratio (PAPR) and to make more efficient use of the power amplifiers in the system, the invention modifies and implements a symbol rotation and inversion-based PAPR reduction algorithm in the adaptive OFDM framework. This joint adaptive physical layer is capable of increasing data rates by roughly 220% in comparison to conventional narrowband techniques at average transmit powers of roughly 7 mW while constrained to a desired BER.

Abstract: The problems of high peak to average power ratio (PAPR) in multi-carrier systems and throughput improvement in multi-carrier systems by PAPR-aware rate adaptive bit loading are addressed by implementing two symbol rotation-inversion algorithms that reduce the peak to average power ratio in multi carrier OFDM systems jointly with rate adaptation. The method combines the benefits of bit allocation and symbol rotation to reduce the PAPR in OFDM communication systems and thus improve system range and robustness to noise. When coupled with adaptive bit loading techniques, these PAPR remediation strategies can substantially increase link throughput. Symbol rotation results in more than one order of magnitude BER reduction for SISO OFDM and one order of magnitude reduction in MIMO OFDM.

Abstract: A link adaptive orthogonal frequency-division multiplexed (OFDM) ultrasonic physical layer is provided that is capable of high data rate communication through metallic structures. The use of an adaptive OFDM subcarrier-based modulation technique mitigates the effects of severe frequency selective fading of the through-metal communication link and improves spectral efficiency by exploiting the slow-varying nature of the channel. To address the potential ill effects of peak-to-average power ratio (PAPR) and to make more efficient use of the power amplifiers in the system, the invention modifies and implements a symbol rotation and inversion-based PAPR reduction algorithm in the adaptive OFDM framework. This joint adaptive physical layer is capable of increasing data rates by roughly 220% in comparison to conventional narrowband techniques at average transmit powers of roughly 7 mW while constrained to a desired BER.

Abstract: An artificial promoter characterized for been a chimerical recombinant DNA molecule such that, when introduced in any class of plant cells, promotes high expression levels of any DNA molecule fused to its 3? end. The basic genetic elements of the molecule described here are: a core promoter with a consensus TATA box, followed by an Exon/Intron/Exon region and a translation enhancer element, all of them artificially constructed. Transcription regulatory elements can be inserted upstream of the promoter here described to confer temporal-, organ- or tissue-specificity to the expression. The designed artificial genetic elements can be functionally inserted between any promoter active in plant cells and any DNA sequence to increase its transcription/translation levels.

Abstract: Generation of genetic constructions based on modified fragments of the hepatitis A virus (HAV) genome, using the strain M2, isolated in Cuba. Nucleotides sequences of these fragments fused to the appropriated localization and regulation signals, are expressed in transgenic plant. The obtained recombinant antigens of the HAV are composed of pentamers and/or empty envelope, able to develop immune response.

Abstract: A fully enclosed toy craft intended for both amusement and educational purposes having the ability to assume a multitude of forms with each form resembling a different type of vehicle. The craft's interior resembles a scaled down version of a commander's cabin in a real craft and includes, among other things, audio visual material, calculating apparatus, and an assortment of readout or instrumentation devices. In addition, an analog computer interacting with various items in the commander's cabin, in response to stimuli provided by the operator moving hand or foot control devices gives the operator the illusion of being in control of a real craft.