An Environmental Monitoring System for Managing Spatiotemporal Sensor Data over Sensor Networks

In a wireless sensor network, sensors collect data about natural phenomena and transmit them to a server in real-time. Many studies have been conducted focusing on the processing of continuous queries in an approximate form. However, this approach is difficult to apply to environmental applications which require the correct data to be stored. In this paper, we propose a weather monitoring system for handling and storing the sensor data stream in real-time in order to support continuous spatial and/or temporal queries. In our system, we exploit two time-based insertion methods to store the sensor data stream and reduce the number of managed tuples, without losing any of the raw data which are useful for queries, by using the sensors' temporal attributes. In addition, we offer a method for reducing the cost of the join operations used in processing spatiotemporal queries by filtering out a list of irrelevant sensors from query range before making a join operation. In the results of the performance evaluation, the number of tuples obtained from the data stream is reduced by about 30% in comparison to a naïve approach, thereby decreasing the query execution time

Magnetoresistive biosensors with on-chip pulsed excitation and magnetic correlated double sampling.

Giant magnetoresistive (GMR) sensors have been shown to be among the most sensitive biosensors reported. While high-density and scalable sensor arrays are desirable for achieving multiplex detection, scalability remains challenging because of long data acquisition time using conventional readout methods. In this paper, we present a scalable magnetoresistive biosensor array with an on-chip magnetic field generator and a high-speed data acquisition method. The on-chip field generators enable magnetic correlated double sampling (MCDS) and global chopper stabilization to suppress 1/f noise and offset. A measurement with the proposed system takes only 20 ms, approximately 50× faster than conventional frequency domain analysis. A corresponding time domain temperature correction technique is also presented and shown to be able to remove temperature dependence from the measured signal without extra measurements or reference sensors. Measurements demonstrate detection of magnetic nanoparticles (MNPs) at a signal level as low as 6.92 ppm. The small form factor enables the proposed platform to be portable as well as having high sensitivity and rapid readout, desirable features for next generation diagnostic systems, especially in point-of-care (POC) settings

Extensor-tendons reconstruction using autogenous palmaris longus tendon grafting for rheumatoid arthritis patients

<p>Abstract</p> <p>Background</p> <p>The purpose of the study is to retrospectively review the clinical outcome of our study population of middle-aged RA patients who had suffered extensor-tendon rupture. We reported the outcome of autogenous palmaris tendon grafting of multiple extensor tendons at wrist level in 14 middle-aged rheumatoid patients.</p> <p>Methods</p> <p>Between Feb. 2000 to Feb. 2004, thirty-six ruptured wrist level extensor tendons were reconstructed in fourteen rheumatoid patients (11 women and three men) using autogenous palmaris longus tendon as a free interposition graft. In each case, the evaluation was based on both subjective and objective criteria, including the range of MCP joint flexion after surgery, the extension lag at the metacarpophalangeal joint before and after surgery, and the ability of the patient to work.</p> <p>Results and Discussion</p> <p>The average of follow-up was 54.1 months (range, 40 to 72 months). The average range of MCP joint flexion after reconstruction was 66°. The extension lag at the metacarpophalangeal joint significantly improved from a preoperative mean of 38° (range, 25°–60°) to a postoperative mean of 16° (range, 0°–30°). Subjectively all patients were satisfied with the clinical results, and achieved a return to their level of ability before tendon rupture. We found good functional results in our series of interposition grafting using palmaris longus to reconstruct extensor tendon defects in the rheumatoid patients.</p> <p>Conclusion</p> <p>Reconstruction for multiple tendon ruptures is a salvage procedure that is often associated with extensor lag and impairment of overall function. Early aggressive treatment of extensor tendon reconstruction using autogenous palmaris longus tendon as a free interposition graft in the rheumatoid wrist is another viable option to achieve good clinical functional result.</p

Synthesis and pinning properties of the infinite-layer superconductor Sr0.9La0.1CuO

We report the high-pressure synthesis of the electron-doped infinite-layer superconductor Sr0.9La0.1CuO2 and its superconducting properties. A Rietveld analysis of X-ray powder diffraction data showed that, within the resolution of the measurement, the sample had purely an infinite-layer structure without any discernible impurities. The superconducting volume fraction and the transition width were greatly improved compared to those in previous reports. The irreversibility field line and the intragranular critical current density were much higher than those of La1.85Sr0.15CuO4 and Nd1.85Ce0.15CuO4. The stronger pinning behaviors are consistent with the strong interlayer coupling due to the short distance between CuO2 planes.Comment: Physica C (in press) 5 pages, 4 figur

Z(3) Flavor Symmetry and Possible Implications

We show in this paper that the Z(3) flavor symmetry, which can successfully produce the tri-bimaximal mixing and flavor pattern of neutrino sector, has a possible explanation in the framework of gauge symmetry by constructing a wavefunction of flavor state particles with the help of the Wilson loop. In this implementation of Z(3) flavor symmetry, we suggest that the flavor charge in weak interaction can be interpreted as a topological charge. Its possible implications and generalizations to the quark sector are also discussed.Comment: 9 pages, no figures, final version for Phys. Lett.