Methods: Simultaneous click here bipolar
filtered at 30-500 Hz and unipolar (high-pass filtered at 30 Hz) signals were recorded during ventricular voltage maps in 24 patients (group A). In five subsequent patients, low voltage surface areas were compared in electroanatomic maps (group B).
Results: Of 2,789 mapping points in group A, filtered unipolar EG amplitude correlated well with bipolar EG amplitude. Agreement of filtered unipolar recordings in classifying sites as > 1.5 mV or <1.5 mV with bipolar EG amplitude was 83%. Discordance was due to unipolar > bipolar amplitude at 83% of the discordant sites, consistent with possible reduction of bipolar amplitude due to direction dependence. Discordance was more frequent during epicardial than endocardial mapping. Double potentials were more frequently observed in bipolar than in unipolar recordings (3.2% vs 1.8%, P < 0.0001). In group B, the mean low-voltage PARP activation surface area (< 1.5 mV) was 70.1 +/- 48.9 cm(2) for bipolar and 61.3 +/- 52.2 cm(2) for filtered unipolar EG maps.
Conclusion: Direction dependent effects on bipolar EG amplitude may influence the identification of substrate for arrhythmias. High-pass filtered unipolar EGs might be a reasonable alternative
to bipolar recordings for creation of voltage maps. (PACE 2012; 35:157-163)”
“Background: Mosquito age and species identification is a crucial determinant of the efficacy of vector control programmes. Near-infrared spectroscopy (NIRS) has previously been applied successfully to rapidly, non-destructively, and simultaneously determine the age and species of freshly anesthetized African
malaria vectors from the Anopheles gambiae s.l. species complex: An. gambiae s. s. and Anopheles arabiensis. However, this has only been achieved on freshly-collected specimens and future applications will require samples to be preserved between field collections and scanning by NIRS. In this study, a sample preservation method (RNAlater (R)) was evaluated for mosquito age and species identification by NIRS find more against scans of fresh samples.
Methods: Two strains of An. gambiae s. s. (CDC and G3) and two strains of An. arabiensis (Dongola, KGB) were reared in the laboratory while the third strain of An. arabiensis (Ifakara) was reared in a semi-field system. All mosquitoes were scanned when fresh and rescanned after preservation in RNAlater (R) for several weeks. Age and species identification was determined using a cross-validation.
Results: The mean accuracy obtained for predicting the age of young (<7 days) or old (>= 7 days) of all fresh (n = 633) and all preserved (n = 691) mosquito samples using the cross-validation technique was 83% and 90%, respectively. For species identification, accuracies were 82% for fresh against 80% for RNAlater (R) preserved.