A pseudojoint estimation of time delay and scale factor for M-wave analysis

A pseudojoint estimation of time scale and time delay between an unknown deterministic transient type signal and a reference signal is proposed. The method is based on the separation between the estimations of the two dependent parameters. The time autocorrelation function (TACF) preserves the time scale and is invariant with respect to the time delay between the signals. The time scale factor can, thus, be estimated independently from time delay using the TACFs of the two signals. After estimating the time scale factor, the signal can be scaled by the estimated amount. The time delay is then estimated without bias due to the time scale factor. To obtain high resolution joint estimates, the time scale factor is estimated in the scale domain from the scale transforms of the TACFs of the two signals. The proposed method has low computational cost. Moreover, the results on synthetic signals show good performance of the method with respect to the Cramér-Rao Lower Bound and the joint Maximum Likelihood Estimation. A possible application of the technique to the analysis of electromyogram (EMG) signals detected during electrically elicited contractions is also presented. In a few representative cases, it is shown that the time scale estimate reveals myoelectric manifestations of muscle fatigue and is less affected by M-wave truncation than spectral EMG attributes.     

Ultrasensitive detection of unstained proteins in acrylamide gels by native UV fluorescence

Visualization of proteins inside acrylamide and other gels usually relies on different staining methods. To omit the protein-staining procedure, we visualized unstained proteins inside acrylamide gels by laser excitation with ultraviolet (UV) light (280 nm, 35 mJ/cm2) and directly detected native UV fluorescence. In one-dimensional gels, a detection limit as low as 1 ng for bovine serum albumin and 5 ng for other proteins with a linear dynamic range (2.7 orders of magnitude) comparable to state of the art fluorescent dyes could be achieved. In addition, the application of this method to 20 microg of a whole cell lysate separated in a two-dimensional gel showed more than 600 spots. Since protein labeling always represents a serious obstacle in protein identification technologies, the working efficiency with our procedure can be considered as a significant improvement for protein visualization and reproducibility in proteomics.     

Bio-inspired solutions for locomotion in the gastrointestinal tract: background and perspectives

This paper illustrates a bio-inspired approach to effective, smooth and safe navigation in the human body and, in particular, in the gastrointestinal tract. This idea originates from the medical need to develop more powerful tools for microendoscopy, which is one of the most challenging frontiers of modern medicine. Understanding motion and perception systems of lower animal forms, such as parasites, worms, insects and snakes, can help to design and fabricate bio-inspired robots able to navigate in tortuous, slippery and difficult-to-access cavities of the human body. A preliminary study of a biomimetic adhesion system for the human tissues is presented in this work and some technological implementations are illustrated and discussed. Finally, some issues concerning the goals of smart and reactive locomotion are considered and the most promising and relevant enabling technologies are discussed.     

Web Filtering: Where,How and Why: Control of Internet use: some considerations about the implications of this type of control in the light of the Italian experience.

A recent study¹ has determined that the average amount of time users spend on the Internet at their workstations is on the order of five and a half hours per week. Italy is in second place after the United Kingdom in use of the Internet from the workplace. When this type of access is available there is also the potential for its abuse. And so it was found that, out of a sample of 200 interviewees, 51% admitted to browsing sites not pertinent to their business during work hours, and, this is how three of the five and half hours are spent. Where exactly? The type of websites visited when one should be working vary from leisure time activities, to shopping, to pornography.So how do companies respond to this problem? In Italy, 55% of the sample admit that they have not yet undertaken any definite actions with regard to this issue, 17% have implemented policies, 7% carry out active system monitoring and 14% use content and surfing filters.     

Polychaete-Like Undulatory Robotic Locomotion in Unstructured Substrates

A biological paradigm of versatile locomotion and effective motion control is provided by the polychaete annelid worms, whose motion adapts to a large variety of unstructured environmental conditions (sand, mud, sediment, water, etc.), and could thus be of interest to replicate by robotic analogs. Their locomotion is characterized by the combination of a unique form of tail-to-head body undulations (opposite to snakes and eels), with the rowing-like action of numerous lateral appendages distributed along their long segmented body. Focusing on the former aspect of polychaete locomotion, computational models of crawling and swimming by such tail-to-head body undulations have been developed in this paper. These are based on the Lagrangian dynamics of the system and on resistive models of its interaction with the environment, and are used for simulation studies demonstrating the generation of undulatory gaits. Several biomimetic robotic prototypes have been developed, whose undulatory actuation achieves propulsion on sand and other granular unstructured environments. Extensive experimental studies demonstrate the feasibility of robot propulsion by tail-to-head body undulations in such environments, as well as the agreement of its qualitative and quantitative characteristics to the predictions of the corresponding computational models.     

Comparison between satellite and ship measurements of sea surface temperature in the north-east Atlantic Ocean

Abstract

A comparison is made between in situ measurements of sea surface temperature (SST) in the north-east Atlantic Ocean, obtained during Cruise 145 of RRS Discovery, and SSTs derived from several overpasses of the Advanced Very High Resolution Radiometer on the NOAA-7 satellite during the same period in March 1984. The objective of the analysis was to test the ability of the satellite to map the detailed features of SST structure and to examine the performance of atmospheric correction and temperature calibration procedures in this context. Gross comparison between all the cloud-free ship and satellite data confirms agreement normally within 1 degC. More detailed comparison of SST structure along the cruise tracks shows that the satellite data are able to identify features with a resolution of 0.3°C.     

Optimal controller for uncertain stochastic polynomial systems with deterministic disturbances

This article presents the optimal quadratic-Gaussian controller for uncertain stochastic polynomial systems with unknown coefficients and matched deterministic disturbances over linear observations and a quadratic criterion. The optimal closed-form controller equations are obtained through the separation principle, whose applicability to the considered problem is substantiated. As intermediate results, this article gives closed-form solutions of the optimal regulator, controller and identifier problems for stochastic polynomial systems with linear control input and a quadratic criterion. The original problem for uncertain stochastic polynomial systems with matched deterministic disturbances is solved using the integral sliding mode algorithm. Performance of the obtained optimal controller is verified in the illustrative example against the conventional quadratic-Gaussian controller that is optimal for stochastic polynomial systems with known parameters and without deterministic disturbances. Simulation graphs demonstrating overall performance and computational accuracy of the designed optimal controller are included.     

The occurrence of isoperoxidases in conference pears

Soluble and ionically-bound peroxidases have been obtained from the pulp and peel of Conference pears. The peel soluble fraction contained the highest level of peroxidase activity. The peel peroxidases, both soluble and ionically bound, were particularly heat stable. Following heat inactivation, regeneration of enzymic activity was observed for the peel peroxidases and soluble pulp enzymes. Plots of the percentage of heat inactivation for the pear peroxidases against heating time were non-linear.     

Microbiology of brines used to mature feta cheese

The microfloras of brines from two commercial factories manufacturing traditional feta cheese were examined over a period of 60 days, which is the normal maturation time for Greek feta. Non-starter lactic acid bacteria were the dominant group, and Lactobacillus paracasei ssp. paracasei and Lactobacillus plantarum were the principal species identified. A number of strains of Debaryomyces hansenii were isolated from the brines, and both the yeasts and the lactobacilli possessed enzymes capable of degrading fat or protein. It is suggested that these microfloras play an important role in the maturation of feta cheese. No recognized pathogens were isolated from the brines of' either factory.