RF I/Q Downconverter With Gain/Phase Calibration

We propose an RF I/Q downconverter including a calibration procedure to compensate for gain and phase mismatch errors. The indirect compensation technique is based on the use of the local oscillator (LO) signal as reference for error measurements. A number of mismatch parameters are first estimated by an algorithm running in the digital signal processing processor following the analog-to-digital converter and then used to correct the downconverted I/Q signals digitally during normal operation. The downconverter has been designed in 0.13-mum CMOS technology. The analog part of the system for calibration adds a negligible area and power consumption with respect to the front-end building blocks. Test results exhibit an image-rejection ratio IRRges48.8 dB for I/Q phase errors up to 15deg and for LO I/Q amplitude and mixer gain mismatch errors up to 10%     

Adaptive filtering for color filter array demosaicking.

Most digital still cameras acquire imagery with a color filter array (CFA), sampling only one color value for each pixel and interpolating the other two color values afterwards. The interpolation process is commonly known as demosaicking. In general, a good demosaicking method should preserve the high-frequency information of imagery as much as possible, since such information is essential for image visual quality. We discuss in this paper two key observations for preserving high-frequency information in CFA demosaicking: (1) the high frequencies are similar across three color components, and (2) the high frequencies along the horizontal and vertical axes are essential for image quality. Our frequency analysis of CFA samples indicates that filtering a CFA image can better preserve high frequencies than filtering each color component separately. This motivates us to design an efficient filter for estimating the luminance at green pixels of the CFA image and devise an adaptive filtering approach to estimating the luminance at red and blue pixels. Experimental results on simulated CFA images, as well as raw CFA data, verify that the proposed method outperforms the existing state-of-the-art methods both visually and in terms of peak signal-to-noise ratio, at a notably lower computational cost.     

Optimization of roasting conditions as an useful approach for increasing antioxidant activity of carob powder

Antioxidant activity, gastrointestinal solubility of polyphenols and formation of different classes of Maillard reaction products (MRPs) that occurs during thermal processing of carob powder was investigated in relation to different roasting time-roasting temperature combinations applied. Principal component analysis (PCA) was used to group carob powders with the aim of proposing optimal roasting conditions for obtaining the one with the highest biological activity that can be expected after undergoing the simulation of gastrointestinal digestion. Results showed that antioxidant activity of carob powder can be significantly increased by roasting due to improved polyphenol solubility and formation of the early-stage MRPs. Fluorescent MRPs, HMF and furfural, known for their toxic properties, were the most abundant in samples roasted under more severe time/temperature conditions. Carob powder roasted at 130 °C for 30 min yielded the highest antioxidant activity and the lowest toxic MRP formation.     

Cobalt excretion in urine: results of a study on workers producing diamond grinding tools and on a control group

A study was carried out on cobalt (Co) excretion in the urine of 12 workers exposed to known cobalt concentrations in the stone cutting diamond wheel production and in six volunteers: four of these were exposed in the same work environment for a whole workshift and the other two were exposed to cobalt in a cabin under experimental conditions. The kinetics of the urinary excretion was multiphase: (i) a first stage of rapid elimination ( ); (ii) a second phase of slower elimination ( ); (iii) a longer period of retention, of the order of years, in subjects with higher exposure. In the control group (4 subjects), the excretion proved to be much faster in the first stage ( h). The different behaviour of the two groups could be related to the different body burden, of cobalt and/or to the possibility of different kinetics induced by continuous exposure to the metal. Moreover, 3 weeks after the removal of the workers from exposure the urinary cobalt concentrations were not within the normal limits of CoU for the general population, (even for workers exposed to cobalt levels of the same order as the TLV). The increase of CoU concentrations in the first 3 h after the end of exposure, stresses the problem of when urine samples for biological monitoring of the workers should be collected. The present study confirms the utility of CoU in discriminating between exposed and non-exposed subjects as well as in assessing high and low level exposure.     

Correlation between extent of myocardial dysfunction and markers of irreversible damage in failing hearts

Using a SOM (self-organizing map) we can classify sequences within a protein family into subgroups that generally correspond to biological subcategories. These maps tend to show sequence similarity as proximity in the map. Combining maps generated at different levels of resolution, the structure of relations in protein families can be captured that could not otherwise be represented in a single map. The underlying representation of maps enables us to retrieve characteristic sequence patterns for individual subgroups of sequences. Such patterns tend to correspond to functionally important regions. We present a modified SOM algorithm that includes a convergence test that dynamically controls the learning parameters to adapt them to the learning set instead of being fixed and externally optimized by trial and error. Given the variability of protein family size and distribution, the addition of this features is necessary. The method is successfully tested with a number of families. The rab family of small GTPases is used to illustrate the performance of the method.     

Proposal for update of Bassini's procedure in the treatment of inguinal hernia under local anesthesia

Inconvenience due to tension along the suture, a relative high recurrence rate, the availability of optimal prosthetic materials and the tendency to reduce hospital stay are the motivations which induced many surgeons to adopt alternative techniques instead of the traditional ones for inguinal hernia repair. Among these latter it is worthwhile to add a personal update of the Bassini's technique: the plasty tailored upon the polypropylene mesh performed in local anesthesia. Thanks to the use of the prosthetic mesh, the plasty is performed using only four stitches tied loosely without much high tension on the conjoined tendon. Such technical expedients reduced postoperative pain and give better warrant for the plasty and allow hernia repair in local anesthesia and on a daily basis.     

Nanocomputing by field-coupled nanomagnets

Demonstrates through simulations the feasibility of using magnetically coupled nanometer-scale ferromagnetic dots for digital information processing. Microelectronic circuits provide the input and output of the magnetic nanostructure, but the signal is processed via magnetic dot-dot interactions. Logic functions can be defined by the proper placements of dots. We introduce a SPICE macromodel of interacting nanomagnets and use this tool to design and simulate the proposed nanomagnet logic units. This SPICE model allows us to simulate such magnetic information processing devices within the same framework as conventional electronic circuits.