Analysis of the intra-night variability of BL Lacertae during its August 2020 flare

We present an analysis of the $BVRI$ photometry of the blazar BL Lacertae on diverse timescales from mid-July to mid-September 2020. We have used 11 different optical telescopes around the world and have collected data over 84 observational nights. The observations cover the onset of a new activity phase of BL Lacertae started in August 2020 (termed as the August 2020 flare by us), and the analysis is focused on the intra-night variability. On short-term timescales, (i) flux varied with ~2.2\,mag in $R$ band, (ii) the spectral index was found to be weakly dependent on the flux (i.e., the variations could be considered mildly chromatic) and (iii) no periodicity was detected. On intra-night timescales, BL Lacertae was found to show bluer-when-brighter chromatism predominantly. We also found two cases of significant inter-band time lags of the order of a few minutes. The duty cycle of the blazar during the August 2020 flare was estimated to be quite high (~90\% or higher). We decomposed the intra-night light curves into individual flares and determined their characteristics. On the basis of our analysis and assuming the turbulent jet model, we determined some characteristics of the emitting regions: Doppler factor, magnetic field strength, electron Lorentz factor, and radius. The radii determined were discussed in the framework of the Kolmogorov theory of turbulence. We also estimated the weighted mean structure function slope on intra-night timescales, related it to the slope of the power spectral density, and discussed it with regard to the origin of intra-night variability.Comment: 46 pages, 19 figures, 8 tables, accepted for publication in The Astrophysical Journal Supplement Series (manuscript version after proof correction

Approach of pulmonologists in Turkey to noninvasive mechanical ventilation use at home for chronic respiratory failure

WOS: 000386262800001PubMed ID: 27266279Introduction: To define approach of pulmonologists in Turkey to noninvasive mechanical ventilation ( NIV) use for chronic respiratory failure ( CRF), the most currently applied technique for home mechanical ventilation. Patients and Methods: A 38-question survey, developed and tested by the authors, was distributed throughout Turkey to 2205 pulmonologists by e-mail. Results: Twenty-seven percent of the pulmonologists responded ( n= 596). Domiciliary NIV was reported to be prescribed by 340 physicians [ 57.1% of all responders and 81% of pulmonologists practicing NIV at clinical practice ( n= 420)]. NIV prescription was associated with physician's title, type of hospital, duration of medical license, total number of patients treated with NIV during residency and current number of patients treated with NIV per week ( p< 0.05). Main estimated indications were listed as chronic obstructive pulmonary disease ( median, 25-75 percentile of the prescriptions: 75%, 60-85), obesity hypoventilation syndrome ( 10%, 2-15), overlap syndrome ( 10%, 0-20) and restrictive lung disease ( 5%, 2-10). For utilization of NIV at home, Bilevel positive airway pressure-spontaneous mode ( 40%, 0-80) and oronasal mask ( 90%, 60-100) were stated as the most frequently recommended mode and interface, respectively. Pressure settings were most often titrated based on arterial blood gas findings ( 79.2%). Humidifier was stated not to be prescribed by approximately half of the physicians recommending domicilliary NIV, and the main reason for this ( 59.2%) was being un-refundable by social security foundation. Conclusion: There is a wide variation in Turkey for prescription of NIV, which is supposed to improve clinical course of patients with CRF. Further studies are required to determine the possible causes of these differences, frequency of use and patient outcomes in this setting

Approach of pulmonologists in Turkey to noninvasive mechanical ventilation use at home for chronic respiratory failure

WOS: 000386262800001PubMed ID: 27266279Introduction: To define approach of pulmonologists in Turkey to noninvasive mechanical ventilation ( NIV) use for chronic respiratory failure ( CRF), the most currently applied technique for home mechanical ventilation. Patients and Methods: A 38-question survey, developed and tested by the authors, was distributed throughout Turkey to 2205 pulmonologists by e-mail. Results: Twenty-seven percent of the pulmonologists responded ( n= 596). Domiciliary NIV was reported to be prescribed by 340 physicians [ 57.1% of all responders and 81% of pulmonologists practicing NIV at clinical practice ( n= 420)]. NIV prescription was associated with physician's title, type of hospital, duration of medical license, total number of patients treated with NIV during residency and current number of patients treated with NIV per week ( p< 0.05). Main estimated indications were listed as chronic obstructive pulmonary disease ( median, 25-75 percentile of the prescriptions: 75%, 60-85), obesity hypoventilation syndrome ( 10%, 2-15), overlap syndrome ( 10%, 0-20) and restrictive lung disease ( 5%, 2-10). For utilization of NIV at home, Bilevel positive airway pressure-spontaneous mode ( 40%, 0-80) and oronasal mask ( 90%, 60-100) were stated as the most frequently recommended mode and interface, respectively. Pressure settings were most often titrated based on arterial blood gas findings ( 79.2%). Humidifier was stated not to be prescribed by approximately half of the physicians recommending domicilliary NIV, and the main reason for this ( 59.2%) was being un-refundable by social security foundation. Conclusion: There is a wide variation in Turkey for prescription of NIV, which is supposed to improve clinical course of patients with CRF. Further studies are required to determine the possible causes of these differences, frequency of use and patient outcomes in this setting

Türkiye'de akut solunum yetmezliğinde noninvaziv mekanik ventilasyon kullanımına göğüs hastalıkları doktorlarının yaklaşımı

Giriş: Noninvaziv mekanik ventilasyon (NIV) akut solunum yetmezliğinin (ASY) tedavisinde, özellikle de kronik akciğer hastalığı olan hastalarda, dünya çapında giderek artan oranlarda kullanılmaktadır. Bu çalışmada Türkiye'deki göğüs hastalıkları doktorlarının ASY tedavisinde NIV kullanımına yönelik yaklaşımını belirlemeyi amaçladık.Materyal ve Metod: Yazarlarca geliştirilen ve test edilen 38 soruluk anket, e-posta yoluyla Türkiye genelinde toplam 2205 göğüs hastalıkları doktoruna iletildi.Bulgular: Katılım oranı %27 (n= 596) idi. Katılanların %71'i klinikte NIV uygulaması yapıyordu. NIV kullanımı ile katılımcıların ünvanı, yaşı, doktorluk süresi, çalıştıkları hastane ve bulunduğu bölge, hasta yükü, asistanlık eğitimi esnasındaki NIV deneyimi ve miktarı, NIV ve yoğun bakım ünitesi (YBÜ) deneyim süreleri ilişkili bulundu (Tablo 1, p= 0.000). ASY'de NIV kullanan 420 katılımcının alt grup analizinde, haftalık takip edilen ortanca hasta sayısı 4 (25 ve 75 persentil: 2.6) idi. Kullananların çoğunluğu servis (%90) ve/veya YBÜ (%86)'de hastalarını takip ederken; %8.4 hasta takibi için sadece YBÜ'yü kullanıyordu. En sık üç endikasyonu kronik obstrüktif akciğer hastalığı (%99.5), obezite hipoventilasyon sendromu (%93.7) ve restriktif akciğer hastalığına (%89.4) bağlı gelişen ASY idi. Kullanıcıların çoğunluğu (%87) NIV'ı KOAH'lı hastaların %60'ından fazlasında kullanmaktaydı ve kullananların %93'ü KOAH'lılarda NIV başarı oranını %60'ın üzerinde olarak bildirmekteydi. Oronazal maske (ortanca, 25 ve 75 persentil: %90, 80,100) ile ev tipi NIV ventilatörler (%50, 10, 85) en sık kullanılan ekipmanlardı.Sonuç: ASY'de NIV kullanımında bölgesel ve hastane kaynaklı, özellikle doktorun deneyimi ile ilişkili değişkenlik mevcuttur. Kılavuzlara ve genel pratiğe uygun olmakla birlikte, mevcut klinik NIV uygulamaları halen arttırılabilinir ve geliştirilebilinir.Introduction: Noninvasive mechanical ventilation (NIV) has been increasingly used worldwide for acute respiratory failure (ARF), especially in patients with chronic lung disorders. We aimed to define the approach of pulmonologists in Turkey to NIV use for ARF management. Materials and Methods: A 38-question survey, developed and tested by authors, was distributed by e-mail to a total of 2.205 pulmonologists in Turkey.Results: Response rate was 27% (n= 596). Seventy-one percent of responders were practicing NIV in clinic. NIV use was found to be associated with responder's academic title, age, duration of medical license, type of physician's hospital and its region, patient load, NIV experience during residency, and duration of NIV and intensive care unit (ICU) experience ( 60% of patients with COPD, and success rate in COPD was reported as over 60% by 93% of users. Oronasal mask (median and IQR 90, 80-100%, respectively) and home care NIV ventilators (median and IQR 50, 10-85%, respectively) were the most commonly utilized equipment.Conclusion: NIV use in ARF varies based on hospital type, region and, especially, experience of the physician. Although consistent with guidelines and general practice, NIV use can still be improved and increased