The Wigner distribution (WD) is perhaps the most prominent quadratic time–frequency signal representation. In this paper, which has mainly tutorial character but also contains some new results, we describe extensions of the WD concept to multidimensional vector signals, nonstationary random processes, linear time-varying systems (deterministic and random), linear signal spaces, and frames. We d...

I n the early 1970s, when recombinant DNA technology became available, scientists exercised a healthy amount of caution. Within just a few years, as effective laboratory safety rules were established, it became clear that DNA recombinant organisms posed no greater risk than any other biotechnology, including particularly agricultural biotechnology. This evident lack of special risk is what has ...

A method for time-frequency signal analysis is presented. Theproposed method belongs to the general class of smoothed pseudo Wignerdistributions. It is derived from the analysis of the Wigner distributiondefined in the frequency domain. This method provides some substantialadvantages over the Wigner distribution. The well-known cross termeffects are reduced or completely rem...

In abiotic degradation the action of light radiation is one of the most important parameters, because polymers undergo degradation due to the action of light (natural or artificial). The aim of this study was to investigate the degradation rate for samples of polypropylene (PP) modified with an organic pro-degradant submitted to ageing in a natural environment and to accelerated ageing test. Th...

The debate about cloning and genetic engineering, which began in 1997, has been strongly influenced by fictional narratives, scripts, and images. They in turn provided the seeds for the creation of various metaphors used in the debate, especially by the media. The flow of metaphors and images associated with cloning is now ebbing away and is being replaced by a new wave of images and metaphors ...

The narrow genetic basis of many crops combined with restrictions on the commercial use of genetically modified plants, has led to a surge of interest in exploring natural biodiversity as a source of novel alleles to improve the productivity, adaptation, quality and nutritional value of crops. Genetic methodologies have been applied to natural variation to improve quality aspects that are assoc...

We give an overview of EMPA, a process algebra for modeling and analyzing concurrent systems where nondeterminism, priorities, probabilities and time are present, aiming at a reasonable trade off between the expressive power of the calculus and the complexity of its underlying theory. 1. Università di Bologna, Dipartimento di Scienze dell’Informazione, Mura Anteo Zamboni 7, 40127 Bologna, Italy...

Socio-economic considerations are included in the regulatory frameworks on genetically modified organisms (GMOs) of many countries. This is a reflection of an increasing interest in and recognition of the necessity to consider a broader range of issues when conducting a GMO risk assessment. At the same time, there are discussions about how socio-economic considerations can be identified and how...