Review of Ukrainian Species of the Genus Meliboeus (Coleoptera, Buprestidae, Agrilinae)

Five Ukrainian species of the genus Meliboeus are reviewed and keyed and the data on their distribution in the Palaearctic Region and Ukraine, examined material and larval host plants are given. A poorly known species Meliboeus morawitzi (Semenov, 1905) is redescribed.Рассмотрены 5 видов рода Meliboeus фауны Украины, представлена определительная таблица видов, даны сведения об изученном материале, распространении в пределах Палеарктики и в природно-географических зонах Украины, кормовых связях личинок. Переописан M. morawitzi (Semenov, 1905)

The internal friction and phase transition of solid oxygen

We report an experimental study of the low frequency internal friction (LTIF) in solid oxygen in temperature range 7–52 K. Comparison of the temperature dependence of IF with data of x-ray diffraction and other thermodynamic and elastic properties, shows that anomalies of temperature dependence of the internal friction are resulted from phase transitions in solid oxygen

Conformal Mappings and Dispersionless Toda hierarchy

Let $\mathfrak{D}$ be the space consists of pairs $(f,g)$, where $f$ is a univalent function on the unit disc with $f(0)=0$, $g$ is a univalent function on the exterior of the unit disc with $g(\infty)=\infty$ and $f'(0)g'(\infty)=1$. In this article, we define the time variables $t_n, n\in \Z$, on $\mathfrak{D}$ which are holomorphic with respect to the natural complex structure on $\mathfrak{D}$ and can serve as local complex coordinates for $\mathfrak{D}$. We show that the evolutions of the pair $(f,g)$ with respect to these time coordinates are governed by the dispersionless Toda hierarchy flows. An explicit tau function is constructed for the dispersionless Toda hierarchy. By restricting $\mathfrak{D}$ to the subspace $\Sigma$ consists of pairs where $f(w)=1/\bar{g(1/\bar{w})}$, we obtain the integrable hierarchy of conformal mappings considered by Wiegmann and Zabrodin \cite{WZ}. Since every $C^1$ homeomorphism $\gamma$ of the unit circle corresponds uniquely to an element $(f,g)$ of $\mathfrak{D}$ under the conformal welding $\gamma=g^{-1}\circ f$, the space $\text{Homeo}_{C}(S^1)$ can be naturally identified as a subspace of $\mathfrak{D}$ characterized by $f(S^1)=g(S^1)$. We show that we can naturally define complexified vector fields \pa_n, n\in \Z on $\text{Homeo}_{C}(S^1)$ so that the evolutions of $(f,g)$ on $\text{Homeo}_{C}(S^1)$ with respect to \pa_n satisfy the dispersionless Toda hierarchy. Finally, we show that there is a similar integrable structure for the Riemann mappings $(f^{-1}, g^{-1})$. Moreover, in the latter case, the time variables are Fourier coefficients of $\gamma$ and $1/\gamma^{-1}$.Comment: 23 pages. This is to replace the previous preprint arXiv:0808.072

Role of vascular endothelial growth factor in non-small cell lung cancer pathogenesis

The angiogenesis is an important process in the pathogenesis of malignancies. It is regulated by various growth factors, with the vascular endothelial growth factor (VEGF) playing the central role. The aim of the present study was to evaluate possible associations of functional VEGF −2578C>A, −634G>C, and +936C>T polymorphisms with the risk for occurrence and progression of non-small cell lung cancer (NSCLC) in patients living in Republic of Belarus. Materials and Methods: A total of 202 patients (147 males and 55 females) diagnosed as having the NSCLC. The control group consisted of 336 individuals (245 males and 91 females) without an oncopathology. The total DNA was isolated from peripheral blood. We investigated the single nucleotide polymorphisms of VEGF (rs 2010963), (rs 699947), (rs 3025039). The genotyping was performed by PCR-RFLP analysis. Results: Our results revealed a marginally significant association of the –2578CC genotype (p=0.002) with a greater degree of tumor spread (Т2–Т4). Heterozygous genotypes –2578СА and +936СT carriers were included into the follow-up group significantly more often (р=0.021 and р=0.012, respectively). Our study demonstrate that VEGF –2578A/C and +936C/T polymorphisms are among the factors determining the individual peculiarities of NSCLC course in this population and can be used for clarifying the prognosis of the disease. Key Words: vascular endothelial growth factor, polymorphism, non-small cell lung cancer

Convergence of the all-time supremum of a L\'evy process in the heavy-traffic regime

In this paper we derive a technique of obtaining limit theorems for suprema of L\'evy processes from their random walk counterparts. For each $a>0$, let $\{Y^{(a)}_n:n\ge 1\}$ be a sequence of independent and identically distributed random variables and $\{X^{(a)}_t:t\ge 0\}$ be a L\'evy processes such that $X_1^{(a)}\stackrel{d}{=} Y_1^{(a)}$, $\mathbb E X_1^{(a)}<0$ and $\mathbb E X_1^{(a)}\uparrow0$ as $a\downarrow0$. Let $S^{(a)}_n=\sum_{k=1}^n Y^{(a)}_k$. Then, under some mild assumptions, $\Delta(a)\max_{n\ge 0} S_n^{(a)}\stackrel{d}{\to} R\iff\Delta(a)\sup_{t\ge 0} X^{(a)}_t\stackrel{d}{\to} R$, for some random variable $R$ and some function $\Delta(\cdot)$. We utilize this result to present a number of limit theorems for suprema of L\'evy processes in the heavy-traffic regime

Stability evaluation of a grid-tied hybrid wind/PV farm joined with a hybrid energy-storage system

This paper presents the stability-evaluation outcomes of a multimachine power system (MMPS) connected with a large-scale hybrid wind farm (WF) and photovoltaic (PV) farm or hybrid wind/PV farm (HWPF) and a hybrid energy-storage system (HESS) consisting of a vanadium redox flow battery (VRFB) and a supercapacitor (SC). A probability scheme is used to determine the rated power of the proposed HESS, where the capacities of the VRFB-ESS and the SC-ESS are designed to effectively utilize their operating features. The control strategy of the HESS is proposed to reduce the pressure of the VRFB-ESS and smooth the output power fluctuations of the HWPF. The steady-state stability, small-signal stability, dynamic performances, and transient simulations of the studied grid-tied HWPF fed to the MMPS with and without the HESS are achieved. The simulation outcomes show that the proposed HESS can enhance the stability and power-smoothing performance of the HWPF fed to the MMPS

GW190814: gravitational waves from the coalescence of a 23 solar mass black hole with a 2.6 solar mass compact object

We report the observation of a compact binary coalescence involving a 22.2–24.3 Me black hole and a compact object with a mass of 2.50–2.67 Me (all measurements quoted at the 90% credible level). The gravitational-wave signal, GW190814, was observed during LIGO’s and Virgo’s third observing run on 2019 August 14 at 21:10:39 UTC and has a signal-to-noise ratio of 25 in the three-detector network. The source was localized to 18.5 deg2 at a distance of - + 241 45 41 Mpc; no electromagnetic counterpart has been confirmed to date. The source has the most unequal mass ratio yet measured with gravitational waves, - + 0.112 0.009 0.008, and its secondary component is either the lightest black hole or the heaviest neutron star ever discovered in a double compact-object system. The dimensionless spin of the primary black hole is tightly constrained to �0.07. Tests of general relativity reveal no measurable deviations from the theory, and its prediction of higher-multipole emission is confirmed at high confidence. We estimate a merger rate density of 1–23 Gpc−3 yr−1 for the new class of binary coalescence sources that GW190814 represents. Astrophysical models predict that binaries with mass ratios similar to this event can form through several channels, but are unlikely to have formed in globular clusters. However, the combination of mass ratio, component masses, and the inferred merger rate for this event challenges all current models of the formation and mass distribution of compact-object binaries