Insights into Mt. Etna’s Shallow Plumbing System from the Analysis of Infrasound Signals, August 2007–December 2009

International audiencePrevious studies performed on Mt. Etna on short anddiscontinuous time intervals indicate the North East Crater (NEC)as the most active source of infrasound. The source mechanism ofNEC infrasound events was modeled as a double resonance. Thislead to infer the connection between the NEC and both thesoutheast crater (SEC) and the eruptive fissure (EF), that opened atthe beginning of the 2008–2009 eruption. Nevertheless, there arestill several open questions that need to be addressed. For instance,the steadiness of NEC event features should be studied, as well asthe orderliness of spectral changes of NEC events time-related toeruptive activity of other vents. The investigation of such topics isstrongly enhanced by the possibility of analysing infrasound signalsduring year-long time periods. With this aim about 40,000 infra-sound events, recorded at Mt. Etna from August 2007 to December2009 were analysed by using spectral and location techniques. Itwas noted in particular that the NEC events featured periods withvery steady waveforms and spectral characteristics lasting fromdays to months with slow or sudden variations. The most importanteruptive episodes occurring at the SEC or the EF were accompa-nied by significant spectral changes in NEC events. In light of suchsystematic behaviour the connection between the NEC and theSEC/EF plumbing systems was not considered temporary but ratherstable even during a relatively long time interval (2006–2009).Moreover, study of NEC event spectral features and their changesover multiple years supports the double resonance source model.Such a model, together with the inferred connections between NECand SEC/EF feeding systems, implies that level fluctuations of amagma column inside the NEC conduit correspond to magmastaticpressure decrease/increase inside the main plumbing syste

A controlled study on the effect of verapamil on atrial tachycaarrhythmias in patients with brady-tachy syndrome implanted with a DDDR pacemaker.

While verapamil has been proposed as a treatment for reducing electrophysiological remodeling due to atrial fibrillation and atrial tachyarrhythmias, no previous study has tested its effects in brady-tachy patients implanted with a dual-chamber pacemaker. Fourteen patients with frequent episodes of atrial fibrillation (> or =2 episodes/month) in the setting of brady-tachy syndrome, implanted with a DDDR pacing system with extensive monitor function (Selection 900, Vitatron) were enrolled. Four months after implantation, they were randomly allocated to a 2-month period of treatment with verapamil (240 mg/day) or to no treatment, followed by a crossover. The burden of atrial tachyarrhythmias, the total number of hours spent in atrial tachyarrhythmia and the mean number of hours per day spent in atrial tachyarrhythmia were retrieved from diagnostic devices. The accuracy of atrial tachyarrhythmias detection was confirmed independently by two observers. The main results showed that treatment with verapamil was associated with a trend towards an higher percentage of atrial pacing in comparison with control (mean value+/-S.D.=63.2+/-29.9% vs. 57.3+/-30.6%, median value 53% vs. 49%, P value at Wilcoxon signed rank test=0.069), but without any significant reduction in atrial tachyarrhythmia burden (4.5+/-11.8 vs. 3.3+/-9.1%) or total hours spent in atrial tachyarrhythmia (65+/-161 vs. 48+/-131 h). Palpitation episodes were not significantly reduced by verapamil treatment in comparison with control (10.3+/-7.8 vs. 6.1+/-6.5). In conclusion, verapamil does not exert any beneficial effect on documented episodes of atrial tachyarrhythmia in patients with brady-tachy syndrome implanted with a DDDR device. Moreover, this drug was ineffective in reducing the number of palpitation episodes reported by the patient

A controlled study on the effect of verapamil on atrial tachycaarrhythmias in patients with brady-tachy syndrome implanted with a DDDR pacemaker.

While verapamil has been proposed as a treatment for reducing electrophysiological remodeling due to atrial fibrillation and atrial tachyarrhythmias, no previous study has tested its effects in brady-tachy patients implanted with a dual-chamber pacemaker. Fourteen patients with frequent episodes of atrial fibrillation (> or =2 episodes/month) in the setting of brady-tachy syndrome, implanted with a DDDR pacing system with extensive monitor function (Selection 900, Vitatron) were enrolled. Four months after implantation, they were randomly allocated to a 2-month period of treatment with verapamil (240 mg/day) or to no treatment, followed by a crossover. The burden of atrial tachyarrhythmias, the total number of hours spent in atrial tachyarrhythmia and the mean number of hours per day spent in atrial tachyarrhythmia were retrieved from diagnostic devices. The accuracy of atrial tachyarrhythmias detection was confirmed independently by two observers. The main results showed that treatment with verapamil was associated with a trend towards an higher percentage of atrial pacing in comparison with control (mean value+/-S.D.=63.2+/-29.9% vs. 57.3+/-30.6%, median value 53% vs. 49%, P value at Wilcoxon signed rank test=0.069), but without any significant reduction in atrial tachyarrhythmia burden (4.5+/-11.8 vs. 3.3+/-9.1%) or total hours spent in atrial tachyarrhythmia (65+/-161 vs. 48+/-131 h). Palpitation episodes were not significantly reduced by verapamil treatment in comparison with control (10.3+/-7.8 vs. 6.1+/-6.5). In conclusion, verapamil does not exert any beneficial effect on documented episodes of atrial tachyarrhythmia in patients with brady-tachy syndrome implanted with a DDDR device. Moreover, this drug was ineffective in reducing the number of palpitation episodes reported by the patient

Insights into Mt. Etna’s Shallow Plumbing System from the Analysis of Infrasound Signals, August 2007–December 2009

Previous studies performed on Mt. Etna on short and discontinuous time intervals indicate the North East Crater (NEC) as the most active source of infrasound. The source mechanism of NEC infrasound events was modeled as a double resonance. This lead to infer the connection between the NEC and both the southeast crater (SEC) and the eruptive fissure (EF), that opened at the beginning of the 2008–2009 eruption. Nevertheless, there are still several open questions that need to be addressed. For instance, the steadiness of NEC event features should be studied, as well as the orderliness of spectral changes of NEC events time-related to eruptive activity of other vents. The investigation of such topics is strongly enhanced by the possibility of analysing infrasound signals during year-long time periods. With this aim about 40,000 infrasound events, recorded at Mt. Etna from August 2007 to December 2009 were analysed by using spectral and location techniques. It was noted in particular that the NEC events featured periods with very steady waveforms and spectral characteristics lasting from days to months with slow or sudden variations. The most important eruptive episodes occurring at the SEC or the EF were accompanied by significant spectral changes in NEC events. In light of such systematic behaviour the connection between the NEC and the SEC/EF plumbing systems was not considered temporary but rather stable even during a relatively long time interval (2006–2009). Moreover, study of NEC event spectral features and their changes over multiple years supports the double resonance source model. Such a model, together with the inferred connections between NEC and SEC/EF feeding systems, implies that level fluctuations of a magma column inside the NEC conduit correspond to magmastatic pressure decrease/increase inside the main plumbing system. These findings open up new and interesting possibilities for monitoring magma pressure changes inside the Mt. Etna plumbing system

CAN GROUP EDUCATION IMPROVE ADHERENCE AND ENHANCE BREAST CANCER REHABILITATION AFTER AXILLARY DISSECTION? A RANDOMIZED CLINICAL TRIAL

The objective of this study was to explore the effectiveness of an early-onset, self-administered rehabilitation protocol supported by a group-based educational program and visual material (GRV) in patients who had undergone axillary lymph node dissection (ALND). A total of 186 patients were randomly assigned either to the GRV (n = 93) or to the usual rehabilitation (UR) (n = 93). Patients in the GRV program received group education supported by visual information while the UR program was conducted on an individual basis, and it was not supported by visual information. Primary endpoint was adherence to treatment. Secondary endpoints were shoulder range of motion, lymphedema, disability, pain, quality of life, patient satisfaction, and time devoted to each patient. They were measured at baseline and at post-intervention. The groups did not significantly differ in any outcome measure at post-intervention. While both GRV and UR programs yielded similar high improvements, the average time devoted to each patient was significantly lower in the GRV program. The findings in this study suggest that the usual one-to-one education approach is not superior to a group approach in rehabilitation for breast surgery involving ALND. GRV may constitute a time-efficient alternative to traditional one-to-one approache