We continue the search for luminous blue variables (LBVs) in Local Volume galaxies in order to study their fundamental parameters. In this paper, we report the discovery of two new LBVs in the dwarf irregular galaxy NGC1156. Both stars exhibit spectral variability simultaneously with strong brightness variations: Delta R-c = 0.84 +/- 0.23(m) for J025941.21+251412.2 and Delta R-c = 2.59 +/- 0.10(m) for J025941.54+251421.8. The bolometric luminosities of the stars are in the range of L-Bol approximate to (0.8-1.6) x 10(6) L-circle dot. These values are corrected for reddening A(V) approximate to 0.9 and are given for the distance to the galaxy D = 7.0 +/- 0.4 Mpc, which we have measured by the tip of the red-giant branch method. Both stars are above the Humphreys-Davidson limit in the region of relatively low temperatures, T-eff less than or similar to 10 kK, on the temperature-luminosity diagram. J025941.54+251421.8 had a temperature below the hydrogen ionization threshold at maximum brightness, exhibiting behaviour very similar to that of the known LBV R71 during its 2012 outburst. We have estimated the masses of the detected LBVs and studied the properties of their stellar environment. We discuss our results within the framework of both a single star and a binary system evolution scenario for LBVs.

A systematical theoretical work on physisorption of H2 molecules by both pristine and Li+-decorated perhydroxylated pillar[6]arene (PPA) in the gas phase has been performed by using density functional theory (DFT) and 0th order symmetry-adapted perturbation theory calculations (SAPT0). A complementary analysis using ab initio molecular dynamics (AIMD), atoms-in-molecules (AIM) and independent gradient model (IGM) methods has also been done. Our calculations have shown that H2 molecules can be adsorbed favorably inside the PPA hollow compared with pristine graphene. However, the obtained magnitudes of adsorption energy (Ead) fall outside the optimal range of energies for hydrogen storage. On the other hand, Li+ decoration has drastically improved both Ead and quantity of adsorbed hydrogen molecules. It has been established that each cation center is capable of uptaking from one to five H2 molecules per Li+, and their Ead are in the range from -3.57 to -5.40 kcal/mol. SAPT0 calculations have indicated the prevalence of London dispersion or induction forces in the cases of adsorption inside PPA hollows and on Li+, respectively. AIM and IGM analyses have exhibited that a noncovalent bonding exists between Li+ and H2, and the adsorbed H2 molecules are undissociated. AIMD simulations allow estimating gravimetric densities (GD) at various temperatures, and the maximal GD have been calculated to be 6.0, 4.8, and 3.8% at T = 77, 233, and 300 K, respectively. Besides this, AIMD calculations validate stability of studied structures and the quantity of hydrogen adsorbed. We believe that some of the considerations derived herein establish the high potential of the studied PPA models for hydrogen storage.

Physical adsorption of a set of nine polyaromatic molecules and benzene derivatives on coronene, hexagonal boron nitride (h-BN), and two heterostructure models, mBNC and pBNC, was studied by using density functional theory (DFT), zeroth-order symmetry-adapted perturbation theory (SAPT0), and independent gradient model (IGM) calculations to unveil particular qualities of their interactions. It was established that the heteroatoms embedding into the framework of coronene as an adsorbent introduces changes in its behavior. Moreover, the substitution of the central ring of coronene with a boron nitride moiety adds extra selectivity to adsorption. Decomposition of the total adsorption energy (Ead) obtained by the SAPT0 method was classified as consisting mainly of the dispersion energy term (Edisp), which contributes dramatically (nearly 70%) to the total attractive energy. The least significant one is the induced energy term (Eind), which adds only 5–8% to the attractive interactions. The contribution of the electrostatic (Eel) energy term (nearly 25%) falls between them. The present paper, which employs important model systems, can pave the way for practical implementations of heterostructures as adsorbents.

Deep insight into interactions of various biomolecules with nanomaterials is very important to design novel materials for different applications. The present work studies physical adsorption of valine, an amino acid, on the surfaces of graphene and N-doped graphenes using density functional theory (DFT). Atoms-in-molecules (AIM) and independent gradient model (IGM) analyses have been implemented to reveal the features of interactions in studied complexes. The SAPT0 method has been used to decompose total interaction energy into constituents, which allows one to carry out the complete analysis of the valine/adsorbent interactions. Dispersion forces have been found to play major roles in attractive interactions for the considered complexes. They are followed by electrostatic components. Studies of N-doping effects reveal that valine binds more strongly to the N-doped graphene surfaces in comparison with pristine graphene. The total interaction energy reaches—0.82 eV, which is ∼65% larger than that for pristine graphene. Our results demonstrate that N-doped graphenes with the large interaction energy would be of importance for technical realization of the targeted delivery of valine.

We present a brief summary of our current results on the stellar distribution and population gradients of the resolved stars in the surroundings of ∼ 50 nearby disk galaxies, observed with space-(Hubble & Spitzer) and ground-based telescopes (Subaru, VLT, BTA, Palomar, CFHT, & INT).We examine the radial (in-plane) and vertical (extraplanar) distributions of resolved stars as a function of stellar age and metallicity by tracking changes in the color-magnitude diagram of face-on and edge-on galaxies.Our data show, that the scale length and height of a stellar population increases with age, with the oldest detected stellar populations identified at a large galactocentric radius or extraplanar height, out to typically a few kpc.In the most massive of the studied galaxies there is evidence for a break in number density and color gradients of evolved stars, which plausibly correspond to the thick disk and halo components of the galaxies.The ratio of intermediate-age to old stars in the outermost fields correlate with the gas fraction, while relative sizes of the thick-to-thin disks anticorrelate with galactic circular velocity.

The spatial distribution of stellar populations, the star formation history, and other properties of the dwarf irregular (dIrr) galaxy DDO 190 have been analyzed using color-magnitude diagrams of about 3900 resolved stars and the H alpha fluxes of H II regions. From the mean color index of the red giant branch (RGB), a mean metallicity [Fe/H] = -2.0 is obtained. The I magnitude of the tip of the RGB has been used to estimate the distance. DDO 190 is 2.9 +/- 0.2 Mpc from the Milky Way, 2.1 Mpc from the M94 group (Cn 5-1), 2.4 Mpc from the M81 group, and 2.9 Mpc from the barycenter of the Local Group, all indicating that it is an isolated field galaxy.The surface brightness distribution of the galaxy is well fitted by ellipses of ellipticity e = 1 - a/b = 0.1 and position angle of 82 degrees. The radial star density distribution follows an exponential law of scale length alpha = 43." 4, corresponding to 611 pc. The Holmberg semimajor axis to mu(B) = 26.5 is estimated to be r(26.5)(B) = 3.'0. Stellar populations of different ages in DDO 190 show strong spatial decoupling, the oldest population appearing much more extended than the youngest. Stars younger than 0.1 Gyr occupy only the central 40 " (0.55 kpc); stars younger than a few (similar to 4) Gyr extend out to similar to 80 " (125 kpc), and for larger galactocentric distances, only older stars seem to be present. This behavior is found in all the dIrr galaxies for which spatially extended studies have been performed and could be related to the kinematic history of the galaxy.

We present B, V and R band CCD images of the dwarf galaxy LGS-3 (Pisces dwarf). About 180 stars and diffuse objects were found and processed in these frames. The colour-magnitude diagram shows a prominent red giant branch and a few blue stars only. Details of the morphological properties and colour-magnitude diagram indicate to an intermediate (between dIrr and dSph) type of LGS-3. We estimate the galaxy distance modulus to be about (m - M)(0) = 23.9 +/- 0.3 mag on the basis of the tip of the red giant branch. We measured the galaxy colour to be about B-V diameter 700 pc, which is the smallest one in the Local group.

A photometry in the V, R, I (Cousins) system has been performed for stars in the galaxy Cassiopeia 1. The resulting colour-magnitude (CM) diagram of Cas 1 reveals the existence of blue stars and the absence of red ones. From an analysis of the CM diagram of the galaxy it is concluded that A(v) = 4.0 mag, and the distance modulus (m - M)(0) = 24.5 mag, corresponding to a distance of 790 kpc. The visual magnitude of the galaxy is V = 14.(m)62 (M(v) = -13.(m)8) and the colour index (V - R) = 0.89 mag. From the distance determination the galaxy Cassiopeia 1 is a member of the Local group.

Melioidosis is not a regional problem; the disease has been registered in more than 30 countries, including regions situated far beyond the bounds of endemic territory. Due to increased international travel there exists a potential opportunity for the development of melioidosis in men and animals in any country, including Russia. It is necessary to study melioidosis infection in order to work out preventive measures. Primarily, this study concerns the respiratory form of the disease, which is considered to be the most dangerous epidemic form with a high degree of lethality. The present study contains descriptions of the conditions for the production of microbe aerosols using a dynamic chamber and the main aerodynamic properties of bacterial aerosystems. The dependence of the biological concentration value on the air stream rate in a chamber and the distribution character of aerosol particles in places where animals are exposed to infection and within a longitudinal section of a chamber have been studied, and the value of the correction coefficient used by the determination of aerosol biological concentration has been calculated. As a result, the main natural development of melioidosis in white rats by respiratory contamination and the principal points of pathogenesis by various clinical variants of respiratory melioidosis have been determined.

Problems of optimizing the mode of supplying a materail to the surface of a porous medium are considered for the case when the material is carried by a flow passing through the medium, and is partly absorbed by it. Such a problem arises e.g. when fertilizers are placed on the surface of soil, or when chemical components are supplied to the boundary of a medium within which a reaction with absorption takes place.

Lina Stern wurde als Kind einer deutschsprachi- gen, jüdischen Familie in Libau (heute Liepaya, Lettland) geboren und verbrachte dort ihre Kind- heit und Jugend. Libau gehörte damals zum russischen Reich, wo für junge Frauen, die sich einem akademischen Studium zuwenden wollten, kaum Möglichkeiten bestanden. Die kaiserlichen Universitäten nahmen keine Stu- dentinnen auf, und die wenigen Plätze an den Frauenhochschulen waren hauptsächlich für or- thodoxe Russinnen bestimmt. Als Lina Stern als Zwanzigjährige in die Schweiz reiste, um wie viele ihrer osteuropäischen Landsleute ein Stu- dium im Ausland zu beginnen, hätte sie niemals gedacht, dass sie mehr als ein Vierteljahrhundert in Genf bleiben würde. Sie schrieb sich in der me- dizinischen Fakultät ein und entwickelte schnell ein besonderes Interesse für die Physiologie. Der Lehrstuhlinhaber dieses Faches, Jean-Louis Prevost der Jüngere (1838-1927), erlaubte Lina Stern, im Laboratorium zu arbeiten, und schon im Jahre 1902 - noch vor Abschluss ihres Stu- diums - erschien ihr erster Artikel über eine tier- experimentelle Studie. Wiederum war es Prevost, der die Forschungsarbeit betreute, für welche sie 1903 den Doktortitel erhielt. Danach bot er Lina Stern eine Assistentenstelle an, die ihr erlaubte, ihre Forschungsarbeit in Genf weiterzuführen. Ihre akademische Karriere befand sich auf gutem Wege: 1906 wurde sie Privatdozentin und 1918 die erste Frau Professor an der Universität Genf (1).