Background The majority of patients with Parkinson's disease (PD) have handwriting abnormalities. Micrographia (abnormally small letter size) is the most commonly reported and easily detectable handwriting abnormality in patients with PD. However, micrographia is perhaps the tip of the iceberg representing the handwriting abnormalities in PD. Digitizing tablet technology, which has evolved over the last 2 decades, has made it possible to study the pressure and kinematic features of handwriting. This has resulted in a surge of studies investigating graphomotor impairment in patients with PD. Methods The objectives of this study were to review the evolution of the kinematic analysis of handwriting in PD and to provide an overview of handwriting abnormalities observed in PD along with future directions for research in this field. Articles for review were searched from the PubMed and SCOPUS databases. Results Digitizing tablet technologies have resulted in a shift of focus from the analysis of only letter size to the analysis of several kinematic features of handwriting. Studies based on the kinematic analysis of handwriting have revealed that patients with PD may have abnormalities in velocity, fluency, and acceleration in addition to micrographia. The recognition of abnormalities in several kinematic parameters of handwriting has given rise to the term PD dysgraphia. In addition, certain kinematic properties potentially may be helpful in distinguishing PD from other parkinsonian disorders. Conclusion The journey from micrographia to PD dysgraphia is indeed a paradigm shift. Further research is warranted to gain better insight into the graphomotor impairments in PD and their clinical implications.

A simple method has been developed for estimating wave height from synthetic aperture radar (SAR)imagery obtained by the Seasat satellite. The method is basedon measuring the contrast of the imageand the wavelength of the dominant wave. A calculation has been made for two orbits made by the satellite over the North Atlantic in 1978, usingdigitally processed data supplied by DFVLR in West Germany. Comparison with sea truth measurements shows agreement to within about 20 per cent.

Developing and certifying new aircraft engines is expensive. Once introduced, an engine will have a life measured in decades, and manufacturers and users are reluctant to introduce changes for a number of reasons, not least of which are safety, reliability and cost. Thus the opportunities for new material introduction are few and the consequences of an imperfect decision are high. It is therefore imperative that materials engineers utilize any opportunity to introduce material improvements that are presented. This paper will discuss the risks and necessary actions to achieve successful material insertion and will give examples and attributes of successful and unsuccessful alloy development efforts. IntroductionAero engines require specialty materials that can withstand the demanding environments imposed on the various components and sections that ultimately provide energy and thrust. In general, aero engines require materials that are lightweight, high strength, damage tolerant, high temperature capable, oxidation and corrosion resistant with robust, repeatable mechanical properties that can be readily manufactured into components that are inspectable to ensure the required level of quality and mechanical capability. These requirements are also bounded by the absolute need for lowest possible cost and greatest possible availability.

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