Capacity-approaching block-based transceivers with reduced redundancy

We present a transceiver structure for a frequency selective channel that allows the introduction of reduced redundancy. At the same time we optimize the transmitter and receiver in this structure to maximize the information rate. We show that we can decouple the problem of optimizing the transmitter and the receiver in two different problems by using to the data processing inequality of information theory. The problem of finding the transmitters is a difficult non-linear optimization problem. For that reason we present two simple algorithmic procedures in order to obtain suboptimal solutions. We present simulation results that show that the proposed design outperforms other existing ones in the literature. We also show that the proposed scheme is asymptotically optimal in the sense that it approaches the channel capacity.     

Conoscopic holograms analysis using variations of the Hough transform

The analysis of holograms obtained using a Conoscopic setup is a very complex subject, given their nature. Holograms contain the 3D depth information about an object whose surface is to be measured and later reconstructed. The recovery of depth information has so far been carried out using mathematical transforms in combination with linear regression techniques. Here the Hough transform, a useful Computer Vision technique for detecting features in images is adapted to the analysis of holograms in order to establish distance relationships for a given object. The captured images of holograms are pre‐processed and subsequently analyzed for characteristic patterns that are later used in finding the distance to an object. © 2009 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 19, 10–13, 2009     

1.55-/spl mu/m InP-InGaAsP Fabry-Perot lasers with integrated spot size converters using antiresonant reflecting optical waveguides

We demonstrate a new concept for InGaAsP-InP 1.55-/spl mu/m Fabry-Perot lasers integrated with spot size converters using type-A antiresonant reflecting optical waveguides. The fabrication of such devices allows to avoid the growth of thick layers of quaternary material with low Ga and As fraction, which are difficult to achieve and grow. Reduced far-field divergence angles (10/spl deg/ /spl times/ 27/spl deg/) and improved coupling to cleaved standard single-mode fibers (2.6-dB coupling loss) are achieved. The proposed device is compatible with conventional epitaxial techniques and lithographic methods.     

Market monitoring and performance evaluation - building a market simulator tool

This work presents a software tool that was developed for market monitoring and performance evaluation as well as other applications in planning and market design. Called PROBE (Portfolio Ownership Bid Evaluation), it includes the network model and schedules/optimizes all type of bids and market products in a complex and congested market. The design is in compliance with FERC's standard market design. A great variety of outputs allows for market analysis, determination of potential market power, portfolio analysis, and sensitivity analysis.     

Occurrence of residues of veterinary antibiotics in water,sediment and trout tissue (Oncorhynchus mykiss) in the southern area of Lake Titicaca,Peru

The city of Puno in Peru is the largest producer of trout (Oncorhynchus mykiss) using intensive floating cage systems installed in Lake Titicaca. As a result, the increase in diseases and the use of antibiotics to control them during the production cycle has been documented. We study the impact of antibiotics on drinking water, trout tissues and the lake's aquatic ecosystem. Nine antibiotics were monitored: tetracyclines, sulfonamides and fluoroquinolones. The samples were collected randomly and analyzed by liquid chromatography coupled to mass spectrometry and the solid-phase extraction system. The sediment samples and surface water samples contain high concentrations of antibiotics. All sediments contain fluoroquinolones (3.74 mg kg^?1) and tetracyclines (3.08 mg kg^?1) and the surface water contains fluoroquinolones of up to 408.2 and 652.7 ng L^?1 in the dry and rainy seasons respectively (P > 0.05). Drinking water samples from the city of Puno collected at sampling points with Lake Titicaca as a source of drinking water, reached an average of 188.1 and 222.2 ng L^?1 of ciprofloxacin in dry and rainy seasons respectively. Complementarily, in trout tissues, it reached 7.8 μg kg^?1 in oxytetracycline 8.7 μg kg^?1 in sulfatizole, 4.2 μg kg^?1 in ciprofloxacin and 3.6 μg kg^?1 in sarafloxacin. The presence of these antibiotics in surface water is attributed to the aquaculture activity, in addition to runoff and wastewater, and their presence can have detrimental effects on the aquatic ecosystem, and even affect public health due to the consumption of aquaculture products and drinking water contaminated with antibiotic residues.     

Aggregation of exciter models for constructing power system dynamicequivalents

Constructing a dynamic equivalent for a power system involves several steps: the partition of the system into coherent areas, the coherent area aggregation, and the aggregation of the coherent generators and their control devices. In this paper we investigate the aggregation of exciter models. A trajectory sensitivity method is used to tune the aggregate exciter parameters of the reduced model. The optimal results are used to evaluate the aggregation from the DYNRED program and a weighted MVA method. A three-machine system with one coherent area satisfying the theoretical coherency conditions is used to investigate the impact of the variations of the individual generator, network, and exciter parameters on the aggregate exciter model parameters. The results are then applied to the exciter aggregation of a larger 48-machine system     

Hemodynamic effects of transdermal estradiol alone and combined with norethisterone acetate

Of various vital dyes used to assess schistosomula viability, toluidine blue enabled differential counting of the schistosomula on microscope slides but not in culture wells, whereas methylene blue could be added directly to the schistosomula suspension in culture wells of microtiter plates. Toluidine blue uptake by dead parasites was very fast. It mostly also partially stained damaged but not dead organisms. Its main disadvantage was rapid, nonspecific staining of live schistosomula, requiring prompt counting of a preparation and additional reliance on motility for assessment of viability. Methylene blue staining of dead worms was slower, but it did not stain the live worms until about 1 h after dye application, enabling its addition to a series of preparations for consecutive counting. It did not always stain flattened, dead schistosomula or it stained them an uncontrasting pale blue. This dye remarkably induced movement in seemingly inert and probably damaged worms, thus enabling determination of viability even following poor staining or a lack of staining.     

Capacity of mercury volatilization by mer (from Escherichia coli) and glutathione S-transferase (from Schistosoma mansoni) genes cloned in Escherichia coli

A study was carried out to evaluate the capacity for mercury volatilization by genetically engineered strains that express the mer and glutathione S-transferase genes from Escherichia coli and Schistosoma mansoni, respectively. This method enabled strains containing simultaneously mer and glutathione S-transferase genes to grow in high concentrations of mercuric chloride (30 microg/ml) and to volatilize part of the mercury (248 microg/g cell dry wt.) present in the culture medium, while strains bearing only a single gene, did not have the same behavior. Up to 70% of the total mercury of bacterial volatilization occurred in the first 4 h. Although the findings were preliminary, the genetically engineered strain containing simultaneously the mer and glutathione S-transferase genes show a great potential for bioremediation. It may be used in a closed system to remove by volatilization, and recover mercury (Hg0) from contaminated effluents, such as industrial effluent, for instance.