The rhythm of life: the perfect rhythm of morse code

Morse code is a unique exemplar of the inherent complexities of rhythm. Learning Morse code in wartime presented challenges to expedite skill acquisition. This thesis explored the strategies used to teach and learn Morse code in the second World War and investigated the resourceful techniques used by the WRANS in an empirical study. The first study investigated the teaching and learning strategies of wartime telegraphists to learn Morse code. Five WRANS described a series of techniques to learn Morse code, including rote learning and repetition, visualisation and pattern recognition, intoning and mnemonics, and music. Music provided effective training for the fundamental teaching and learning of Morse code by matching the rhythmical properties of Morse code to music. Music equipped Morse code operators with a unique approach to Morse code instruction. Learning Morse code with music was described as a way of making sense of the ‘rhythm’ and ‘shape’ of the Morse code letters and proved an invaluable aid to learning and teaching Morse code. The second study examined the effectiveness of learning Morse code with the aid of music. Novices formed two groups, Control Group (no music aid) and Music Group (with music aid). Results confirmed the effectiveness of music training in three Morse code letters, Q V, and A in two experiments, the first with known Morse code letters (Q V A) and the second with unknown letters. The Music Group accurately identified 90% of known and unknown Morse code letters compared to the Control Group who identified less then 50% of known and unknown Morse code letters. This thesis explored the transferable attributes of rhythm perception in music as a teaching and learning mechanism for Morse code. There is extensive research on the complex learning and retention of Morse code but the studies in this thesis have indicated that the ground-breaking wartime strategy of music and Morse code is a powerful duo. The investigation of learning and teaching strategies of the WRANS showed that musical rhythm influenced the skill acquisition of Morse code and the perceptual test suggests that current work in rhythm perception extends beyond music pedagogy and has further implications for all cognitive function

The performance of the platelet function analyzer is insufficient to reliably diagnose an increased bleeding tendency in children and adult patients

Despite widespread use of the Platelet Function Analyzer-100 closure time (PFA) as alternative to the bleeding time (BT) for the analysis of primary hemostasis defects, the predictive value is highly variable. This may partly be due to the lack of larger studies, especially in children. We assessed the sensitivity and specificity of the PFA and BT in a large number of patients with increased bleeding tendency due to von Willebrand disease (vWD) and other platelet function disorders (PFD). In addition, we analysed the effect of desmopressin on the PFA in these patients. Methods: PFA and/or BT were measured in a total of 1027 patients (484 children) with increased bleeding tendency. The final diagnosis was ascertained by measurement of specific platelet function tests or clotting factor levels. We also analysed the effect of treatment with 0.3 ig/kg desmopressin on the PFA. Results: Sensitivity and specificity of the PFA were moderate, with no clear differences between children and adults with vWD (Table). The detection of PFD with the PFA was better in children than in adults. The sensitivity of the BT was comparable to the PFA, but the specificity in children was very low. In 54 patients, desmopressin treatment significantly shortened PFA except for one patient with M. Glanzmann and one with vWD. Table represented. Conclusion: Based on this large cohort, the predictive value of the PFA and BT for PFD and vWD in children and adults with increased bleeding tendency is insufficient. The BT had a comparable sensitivity, whereas its specificity was lower than that for PFA, especially in children. PFA seems suitable for measuring the effect of desmopressin

Impact of design-parameters on the optical performance of a highpower adaptive mirror

TNO is developing a High Power Adaptive Mirror (HPAM) to be used in the CO2 laser beam path of an Extreme Ultra-Violet (EUV) light source for next-generation lithography. In this paper we report on a developed methodology, and the necessary simulation tools, to assess the performance and associated sensitivities of this deformable mirror. Our analyses show that, given the current limited insight concerning the process window of EUV generation, the HPAM module should have an actuator pitch of ≥ 4 mm. Furthermore we have modelled the sensitivity of performance with respect to dimpling and actuator noise. For example, for a deformable mirror with an actuator pitch of 4 mm, and if the associated performance impact is to be limited to smaller than 5%, the actuator noise should be smaller than 45 nm (rms). Our tools assist in the detailed design process by assessing the performance impact of various design choices, including for example those that affect the shape and spectral content of the influence function