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

K–Te photocathodes: A new electron source for photoinjectors

K–Te photocathodes deposited on a Mo substrate have been successfully used as an electron source in the free electron laser of University of Twente. Long lifetimes have been measured: after more than 20 h of operation in the accelerator a K–Te cathode with 4.75% initial quantum efficiency still displays a 1.1% quantum efficiency at 259 nm. Moreover, the quantum efficiency of this cathode versus operation time can be fitted by an exponential decay curve, which saturates asymptotically to a 1.03% value, suggesting that a quantum efficiency close to 1% could be sustained for very long operation times. Films degraded by use can be recovered to a quantum efficiency which is close to the initial value, by heating the substrate at temperatures between 100 and 330 °C. A new procedure to obtain K–Te cathodes with high (up to 11%) quantum efficiencies is described

Thrombin Generation as a Method to Identify the Risk of Bleeding in High Clinical-Risk Patients Using Dual Antiplatelet Therapy

Background: Patients using dual antiplatelet therapy after percutaneous coronary intervention are at risk for bleeding. It is currently unknown whether thrombin generation can be used to identify patients receiving dual antiplatelet therapy with increased bleeding risk.Objectives: To investigate whether thrombin generation measurement in plasma provides additional insight into the assessment of bleeding risk for high clinical-risk patients using dual antiplatelet therapy.Methods: Coagulation factors and thrombin generation in platelet-poor plasma were measured in 93 high clinical-risk frail patients using dual antiplatelet therapy after percutaneous coronary intervention. During 12-month follow-up, clinically relevant bleedings were reported. Thrombin generation at 1 and 6 months after percutaneous coronary intervention was compared between patients with and without bleeding events.Results: One month after percutaneous coronary intervention, the parameters of thrombin generation, endogenous thrombin potential, peak height, and velocity index were significantly lower in patients with bleeding in the following months compared to patients without bleeding. At 6 months follow-up, endogenous thrombin potential, peak height, and velocity index were still (significantly) decreased in the bleeding group as compared to non-bleeders. Thrombin generation in the patients' plasma was strongly dependent on factor II, V, and VIII activity and fibrinogen.Conclusion: High clinical-risk patients using dual antiplatelet therapy with clinically relevant bleeding during follow-up show reduced and delayed thrombin generation in platelet-poor plasma, possibly due to variation in coagulation factors. Thus, impaired thrombin-generating potential may be a “second hit” on top of dual antiplatelet therapy, increasing the bleeding risk in high clinical-risk patients. Thrombin generation has the potential to improve the identification of patients using dual antiplatelet therapy at increased risk of bleeding

Tissue factor pathway inhibitor (TFPI) release after heparin stimulation is increased in Type 1 diabetic patients with albuminuria

Department of Internal Medicine, University Hospital, Maastricht, The Netherlands. [email protected] AIMS: To study heparin-stimulated TFPI release in relation to complications in Type 1 diabetic patients. SUBJECTS AND METHODS: Nineteen uncomplicated Type 1 diabetic patients (group I) were compared with 18 patients with retinopathy (group II), and nine patients with retinopathy and albuminuria (group III). Blood samples were taken before (basal) and till 30 min after 5000 IU of heparin i.v. (post-heparin). TFPI activity was measured chromogenically. Von Willebrand factor, tissue plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1) and thrombomodulin were also measured. RESULTS: Basal TFPI activity was higher in group III (121 +/- 10%) compared with group II (111 +/- 8%) or group I (110 +/- 13%) (P < 0.05), and strongly correlated with albuminuria (r = 0.66, P < 0.05). At all time points after heparin administration, TFPI activity in group III was significantly higher than in group I. TFPI activity was also higher in group III than in group II 5-30 min post-heparin. The increase in post-heparin TFPI activity, measured as the incremental area under the curve, was higher in group III compared with group I (65 +/- 7 vs. 59 +/- 4; P < 0.05). Of the other parameters, only thrombomodulin was higher in group III (44 +/- 24 vs. 26 +/- 7 (group II) and 28 +/- 9 ng/ml (group I); P < 0.01). CONCLUSIONS: We conclude that basal and post-heparin TFPI activity is increased in albuminuric patients. The increase in heparin-stimulated TFPI release in patients with albuminuria is higher than in patients with retinopathy or without complications. This could be the result of altered endothelial glycosaminoglycan characteristics

Long-term estrogen treatment of mice with a prothrombotic phenotype induces sustained increases in thrombin generation without affecting tissue fibrin deposition

Thrombosis and Hemostasi