The MHD nature of ionospheric wave packets excited by the solar terminator

We obtained the first experimental evidence for the magnetohydrodynamic (MHD) nature of ionospheric medium-scale travelling wave packets (MSTWP). We used data on total electron content (TEC) measurements obtained at the dense Japanese network GPS/GEONET (1220 stations) in 2008-2009. We found that the diurnal, seasonal and spectral MSTWP characteristics are specified by the solar terminator (ST) dynamics. MSTWPs are the chains of narrow-band TEC oscillations with single packet's duration of about 1-2 hours and oscillation periods of 10-20 minutes. Their total duration is about 4--6 hours. The MSTWP spatial structure is characterized by a high degree of anisotropy and coherence at the distance of more than 10 wavelengths. The MSTWP direction of travelling is characterized by a high directivity regardless of seasons. Occurrence rate of daytime MSTWPs is high in winter and during equinoxes. Occurrence rate of nighttime MSTIDs has its peak in summer. These features are consistent with previous MS travelling ionosphere disturbance (TID) statistics obtained from 630-nm airglow imaging observations in Japan. In winter, MSTWPs in the northern hemisphere are observed 3-4 hours after the morning ST passage. In summer, MSTWPs are detected 1.5-2 hours before the evening ST occurrence at the point of observations, at the moment of the evening ST passage in the magneto-conjugate point. Both the high Q-factor of oscillatory system and synchronization of MSTWP occurrence with the solar terminator passage at the point of observations and in the magneto-conjugate area testify the MHD nature of ST-excited MSTWP generation. The obtained results are the first experimental evidence for the hypothesis of the ST-generated ion sound waves.Comment: 12 pages, 3 figure

Methods and Algorithms of Subsurface Holographic Sounding

In our experiments, we develop and test portable multi-element receiver antenna arrays, electrically scanned in order to immediately obtain a recognizable image of subsurface objects. Two quadrature components of the radar return signal are processed with a Kirchhoff backward migration algorithm. Physical theory is used to assess the quality of the holographic image, and the synthetic aperture approach is developed and tested. The parabolic wave equation and Gaussian beam technique are used in order to take into account refraction effects and to suppress specular reflection from the air-ground interface. Laboratory and field tests confirmed the predicted device parameters

Results of a three-year follow-up and quality of life dynamics after pulmonary thromboendarterectomy

Aim. To evaluate the results of a three-year follow-up of patients with chronic thromboembolic pulmonary hypertension (CTEPH) and quality of life (QOL) dynamics after pulmonary thromboendarterectomy (PTE).Material and methods. The study included 125 patients with CTEPH aged 49,7± 11,9 years. Three-year follow-up included the recording of adverse cardiovascular events, surgeries, death during the period from the end of hospitalization and up to three years. The SF-36 questionnaire was used to assess physical and mental wellbeing before and three years after PTE. Multivariate linear regression was used to assess the factors affecting QOL in the long-term postoperative period.Results. During a three-year follow-up, adverse cardiovascular events was recorded in 1,9% of patients. One patient underwent coronary artery bypass graft surgery and one patient — cholecystectomy. Reoperative PTE was not carried out. The overall three-year survival rate was 90,4%.At baseline, patients with CTEPH had a low level of physical and mental well-being (<40 points). Three years after the operation, these parameters significantly increased (p<0,05), but did not exceed 50 points. Multivariate linear regression revealed an unfavorable effect of early postoperative residual pulmonary hypertension on the physical health three years after PTE. Other factors (age, sex, body weight, comorbidity, hospital acquired complications) did not affect the physical and emotional aspects of QOL.Conclusion. Three-year survival rate in patients with CTEPH after PTE was 90,4%. During the follow-up period, no recurrent thromboembolic events were recorded. Adverse cardiovascular events were recorded in 1,9% of patients. Three years after surgery, the physical and mental health increased in comparison with preoperative values, but did not exceed 50 points on the SF-36 questionnaire. The physical aspect of QOL after surgery is affected by early postoperative residual pulmonary hypertension

Search for Chelyabinsk Meteorite Fragments in Chebarkul Lake Bottom (GPR and Magnetic Data)

The paper summarizes experimental efforts of the Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation (IZMIRAN) undertaken in search of the biggest part of Chelyabinsk meteorite in the bottom of lake Chebarkul, South Ural, Russia, and to estimate the ecological effects of its subsequent excavation

ENDOVASCULAR TREATMENT OF THE RESIDUAL THROMBOEMBOLIC PULMONARY HYPERTENSION AFTER PULMONARY THROMBENDARTERECTOMY WITH THE DENERVATION SYSTEM SYMPLICITY

Aim. To assess the safety and efficacy of radiofrequency denervation of pulmonary artery (PA) with the Simplicity system in patients with residual pulmonary hypertension (PH) after the thromberarterectomy surgery.Material and methods. To the study, 12 patients included, with the signs of residual PH (by echocardiography data, mean PH pressure ≥25 mmHg), who had undergone surgery (thrombendarcterectomy) for chronic thromboembolic PH. Mean time interval between the diagnosis of PH and pulmonary denervation was 8,5 years. After catheterization of the right chambers of the heart and tensiometry in small circle circulation, the spot circular radiofrequency denervation performed of the right and left PH at the area of ostia, with ablation catheter Simplicity. The success was defined by decrease of mean PA pressure >10 mmHg, absence of complications, exercise tolerance increase after the procedure immediately and in 12 months.Results. At long term period after the intervention there was significant decrease of mean PA pressure from 58±6 to 33±4 mmHg (p<0,01), of pulmonary vascular pressure from 8,6±2,1 to 3,2±1,4 mmHg (p<0,01) and increase of exercise tolerance from 321±19 m to 487±29 m (p<0,01). During the follow up period, 1 patient died in 8 months after inclusion due to severe gastrointestinal bleeding. The rest did not present with adverse events or non­planned hospitalizations. Nine patients noted significant improvement of general health, decrease of dyspnea and fatigue, 3 patients had discontinued sildenafil. There were no complications at PA radiofrequency ablation procedure (death, arrhythmias, PA perforation, acute PA thrombosis in the place of access, bleeding).Conclusion. Utilization of the Simplicity system in PA denervation is safe and effective. Further randomized studies in need to confirm clinical benefits from the procedures in PH patients