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Chemical etching has long been established as a reliable means of recovering defaced characters such as serial numbers. Although successful restorations can present clearly defined characters, a preliminary assessment of proficiency test results shows varied participant interpretations of samples marked with the same characters. Thus, a study was completed to determine if specific alphanumeric characters are more likely to be misidentified, comprising a practical exercise and analysis of 16 compiled proficiency test results. The practical exercise involved 64 steel plates stamped with six randomized characters that were removed and chemically restored. Participants individually assessed the plates and provided their interpretations. A total of 39 participants of various backgrounds and experience in serial number restorations were used in this study. After comparing participant interpretations with the ground truth, characters more prone to be misidentified were determined. The proficiency test results showed that the most frequently misidentified characters were the letters B and N, among a limited set. Whilst the practical assessment found a notable increase in misidentifications for the letters G, Q and S. Interestingly, none of these characters were used in the proficiency tests. It is hoped that the results of this study raise awareness for forensic examiners undertaking restorations. [ABSTRACT FROM AUTHOR]

Abstract: Mental rotation is a task known to activate the parietal cortical regions. The present study aimed to investigate whether there is differential activation of regions within the parietal lobe and to reveal functional subspecialisation of this region by examining the effects of increasing angle of rotation. Functional magnetic resonance imaging was performed in nine healthy female subjects whilst undertaking a parametric mental rotation task. The task comprised 6 alphanumeric characters presented in their normal or mirror-reversed orientation. Behaviourally, subjects showed increased reaction times with increased angle of rotation, with differential effects between the alphanumeric characters; numbers having greater reaction times than letters. BOLD signal increase was observed bilaterally in the middle occipital gyrus and medial frontal gyrus, in the right superior and inferior parietal lobules and in the left superior temporal gyrus. Parametric increases in activation with increasing angle of rotation were observed bilaterally in the superior and inferior parietal lobules and in the right medial frontal gyrus, with greater parametric effects in the superior parietal lobules compared to the inferior parietal lobules. Our findings suggest subspecialisation of the posterior parietal lobules during mental rotation, with differential responses in the superior and inferior regions. [Copyright &y& Elsevier]

This article describes a self-powered system that uses chemical reactions-the thermal excitation of alkali metals-to transmit coded alphanumeric information. The transmitter (an "infofuse") is a strip of the flammable polymer nitrocellulose patterned with alkali metal ions; this pattern encodes the information. The wave-lengths of 2 consecutive pulses of light represent each alphanumeric character. While burning, infofuses transmit a sequence of pulses (at 5-20 Hz) of atomic emission that correspond to the sequence of metallic salts (and therefore to the encoded information). This system combines information technology and chemical reactions into a new area-"infochemistry"-that is the first step toward systems that combine sensing and transduction of chemical signals with multicolor transmission of alphanumeric information. [ABSTRACT FROM AUTHOR]