Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. VIII: The Eighth Year (2015-2016)

Continuing the project described by Kato et al. (2009, arXiv:0905.1757), we collected times of superhump maxima for 128 SU UMa-type dwarf novae observed mainly during the 2015-2016 season and characterized these objects. The data have improved the distribution of orbital periods, the relation between the orbital period and the variation of superhumps, the relation between period variations and the rebrightening type in WZ Sge-type objects. Coupled with new measurements of mass ratios using growing stages of superhumps, we now have a clearer and statistically greatly improved evolutionary path near the terminal stage of evolution of cataclysmic variables. Three objects (V452 Cas, KK Tel, ASASSN-15cl) appear to have slowly growing superhumps, which is proposed to reflect the slow growth of the 3:1 resonance near the stability border. ASASSN-15sl, ASASSN-15ux, SDSS J074859.55+312512.6 and CRTS J200331.3-284941 are newly identified eclipsing SU UMa-type (or WZ Sge-type) dwarf novae. ASASSN-15cy has a short (~0.050 d) superhump period and appears to belong to EI Psc-type objects with compact secondaries having an evolved core. ASASSN-15gn, ASASSN-15hn, ASASSN-15kh and ASASSN-16bu are candidate period bouncers with superhump periods longer than 0.06 d. We have newly obtained superhump periods for 79 objects and 13 orbital periods, including periods from early superhumps. In order that the future observations will be more astrophysically beneficial and rewarding to observers, we propose guidelines how to organize observations of various superoutbursts.Comment: 123 pages, 162 figures, 119 tables, accepted for publication in PASJ (including supplementary information

Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae

We systematically surveyed period variations of superhumps in SU UMa-type dwarf novae based on newly obtained data and past publications. In many systems, the evolution of superhump period are found to be composed of three distinct stages: early evolutionary stage with a longer superhump period, middle stage with systematically varying periods, final stage with a shorter, stable superhump period. During the middle stage, many systems with superhump periods less than 0.08 d show positive period derivatives. Contrary to the earlier claim, we found no clear evidence for variation of period derivatives between superoutburst of the same object. We present an interpretation that the lengthening of the superhump period is a result of outward propagation of the eccentricity wave and is limited by the radius near the tidal truncation. We interpret that late stage superhumps are rejuvenized excitation of 3:1 resonance when the superhumps in the outer disk is effectively quenched. Many of WZ Sge-type dwarf novae showed long-enduring superhumps during the post-superoutburst stage having periods longer than those during the main superoutburst. The period derivatives in WZ Sge-type dwarf novae are found to be strongly correlated with the fractional superhump excess, or consequently, mass ratio. WZ Sge-type dwarf novae with a long-lasting rebrightening or with multiple rebrightenings tend to have smaller period derivatives and are excellent candidate for the systems around or after the period minimum of evolution of cataclysmic variables (abridged).Comment: 239 pages, 225 figures, PASJ accepte

ПРОДУКЦИЯ ФАКТОРОВ РОСТА И ДЕСКВАМАЦИЯ ЭНДОТЕЛИОЦИТОВ В СЕРДЦЕ ПРИ ИШЕМИЧЕСКОЙ КАРДИОМИОПАТИИ

oai:oai.kpccz.elpub.ru:article/1324Highlights Dysregulation of angiogenesis may be the pathogenetic factor of ischemic cardiomyopathy (ICMP). Aim. To determine the content of growth factors and desquamated endothelial cells (DEC) in the blood from the coronary sinus and ulnar vein in association with the number of progenitor endothelial cells (PEC) in the blood from the ulnar vein in patients with coronary heart disease (CHD), suffering and not suffering from ICMP.Methods. The study included 30 patients with ICMР and 22 patients with CHD, and 18 healthy donors. The content of DEC (CD45–CD146+) was determined in blood from the cubital vein (peripheral) and coronary sinus, and the content of DEC (CD14+CD34+VEGFR2+) was determined in peripheral blood by flow cytometry (antibodies “BD Biosciences”, USA). The concentrations of VEGF-A, VEGF-B, PDGF, SDF-1, SCF, FGF-1, TGF-β1 in blood plasma from both locations were evaluated by multiplex analysis (set “Cloud-Clone Corp.”, USA).Results. The content of DEC in peripheral blood was elevated in patients with CHD of both groups, and in patients with ICMP in sinus blood was higher than in peripheral. At the same time, in patients with CHD without cardiomyopathy, an excess of PEC and SDF-1 in the blood from the ulnar vein was established in combination with an increase in the concentration of PDGF and a decrease in the content of VEGF-B in the blood from the coronary sinus relative to the parameters of systemic blood flow. In patients with ICMP, these changes were not detected, but there was an increase in the concentration of TGF-β1 in sinus blood compared with peripheral blood. Regardless of the presence of ICMP, the concentration of SCF, FGF-1, VEGF-A in the blood from the ulnar vein corresponded to the norm and that in sinus blood; the content of VEGF-A in the coronary bloodstream exceeded its systemic level.Conclusion. In patients with ICMP, desquamation of the coronary vascular endothelium is enhanced against the background of violations of its repair processes due to insufficient (relative to CHD without cardiomyopathy) mobilization of PEC from the bone marrow due to the absence of an excess of SDF-1 in the blood and their insufficient homing into the myocardium due to weak PDGF production in the heart.Основные положенияПатогенетическим фактором ишемической кардиомиопатии может быть нарушение регуляции ангиогенеза. Цель. Определить содержание факторов роста и десквамированных эндотелиальных клеток (ДЭК) в крови из коронарного синуса и локтевой вены в ассоциации с численностью прогениторных эндотелиальных клеток (ПЭК) в крови из локтевой вены у больных ишемической болезнью сердца (ИБС), страдающих и не страдающих ишемической кардиомиопатией (ИКМП).Материалы и методы. В исследование включили 30 пациентов с ИБС и ИКМП, 22 больных ИБС без ИКМП, 18 здоровых доноров. Содержание ДЭК (CD45–CD146+) определяли в крови из локтевой вены (периферическая) и коронарного синуса (синусовая), а содержание ПЭК (CD14+CD34+VEGFR2+) – в периферической крови методом проточной цитофлуориметрии (антитела BD Biosciences, США). В плазме обоих образцов крови оценивали концентрацию VEGF-A, VEGF-B, PDGF, SDF-1, SCF, FGF-1, TGF-β1 методом мультиплексного анализа (набор Cloud-Clone Corp., США).Результаты. Содержание ДЭК в периферической крови было повышенным у больных ИБС обеих групп, а в синусовой крови у пациентов с ИКМП было выше, чем в периферической. У больных ИБС без ИКМП установлен избыток ПЭК и SDF-1 в крови из локтевой вены в сочетании с увеличением концентрации PDGF и снижением содержания VEGF-В в крови из коронарного синуса относительно параметров системного кровотока. У пациентов с ИКМП данные изменения не выявлены, но отмечен рост концентрации TGF-β1 в синусовой крови по сравнению с периферической. Вне зависимости от ИКМП концентрация SCF, FGF-1, VEGF-А в крови из локтевой вены соответствовала норме и таковой в синусовой крови; содержание VEGF-А в коронарном кровотоке превышало системный уровень.Заключение. При ИКМП усилена десквамация эндотелия коронарных сосудов на фоне нарушений его репарации за счет недостаточной (относительно ИБС без ИКМП) мобилизации ПЭК из костного мозга ввиду отсутствия избытка SDF-1 в крови и недостаточного их хоминга в миокард вследствие слабой продукции PDGF в сердце