The Evolution of Compact Binary Star Systems

We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and BHs are thought to be the primary astrophysical sources of gravitational waves (GWs) within the frequency band of ground-based detectors, while compact binaries of WDs are important sources of GWs at lower frequencies to be covered by space interferometers (LISA). Major uncertainties in the current understanding of properties of NSs and BHs most relevant to the GW studies are discussed, including the treatment of the natal kicks which compact stellar remnants acquire during the core collapse of massive stars and the common envelope phase of binary evolution. We discuss the coalescence rates of binary NSs and BHs and prospects for their detections, the formation and evolution of binary WDs and their observational manifestations. Special attention is given to AM CVn-stars -- compact binaries in which the Roche lobe is filled by another WD or a low-mass partially degenerate helium-star, as these stars are thought to be the best LISA verification binary GW sources.Comment: 105 pages, 18 figure

Stimulation of Wood Degradation by Daedaleopsis confragosa and D. tricolor

Biological pretreatment of the lignocellulosic residues, in which white-rot fungi have a crucial role, has many advantages compared to the chemical, physical, and physico-chemical methods of delignification and therefore attracts increasing scientific attention. Regarding the fact that properties and capacities of the ligninolytic enzymes of Daedaleopsis spp. are still unknown, the aim of this study was to research how nitrogen sources and inducers affect the potential of Daedaleopsis confragosa and Daedaleopsis tricolor to degrade cherry sawdust. NH4NO3, (NH4)2SO4, and peptone were tested as nitrogen sources, while veratryl alcohol, p-anisidine, vanillic acid, and phenylmethylsulfonyl fluoride were the studied inducers. As Mn-dependent peroxidase and laccase were the leader enzymes and cherry sawdust/peptone medium the best stimulator of their activities, the effect of inducers on delignification potential of these species was studied during fermentation of that substrate. Veratryl alcohol was the best stimulator of laccase and phenylmethylsulfonyl fluoride of Mn-dependent peroxidase activity (27,610.0 and 1338.4 U/L, respectively). These inducers also increased cherry sawdust delignification selectivity, particularly in D. tricolor in the presence of phenylmethylsulfonyl fluoride (lignin:hemicellulose:cellulose = 32.1%:0.9%:11.7%). Owing to the presented results, studied species could have an important role in the phase of lignocellulose pretreatment in various biotechnological processes. © 2018, Springer Science+Business Media, LLC, part of Springer Nature