178 research outputs found
The role of the state in the formation of a qualitative level of human capital in the Republic of Belarus
The article considers the theoretical aspects of the "human resource" concept, analyzes the approach to the formation of the human capital of the labour resources, the role of the state in the formation of the human capital of the workers
Exchange Risk Hedging When Carrying Out Exchange Operations
The article analyses the problems caused by the establishment of a floating market exchange rate regime in the Republic of Belarus. The liberalization of the currency market makes it necessary to use the strategies of risk hedging due to unfavorable changes in the exchange rate dynamics
Ecologization of the Economy: Foreign Aspect
The article considers the experience of developed countries in the field of ecologization the economy and specific actions aimed at protecting the environment, the results of a successful environmental policy pursued by the European Union in recent years, the influence of environmental taxation to stimulate work with alternative energy sources
Friedrich Nietzsche’s poetry in the context of the culture at the turn of the XIX–XX centuries
This article examines the poetic legacy of Friedrich Nietzsche in the context of the culture of the turn of the nineteenth and twentieth centuries. Lyric poetry reacts quickly and vividly to the changes in the cultural consciousness of the era. With the help of literary and culturological analysis it is shown how the main worldview concepts of the fin de siècle are reflected in the Nietzsche’s poetry. It is presented both as a paraphrase to his philosophy and as an independent creative element that captured the «spirit of the time».В статье рассматривается поэтическое наследие Фридриха Ницше в контексте культуры рубежа XIX–XX веков. Лирическая поэзия быстро и ярко реагирует на изменения в культурном сознании эпохи. При помощи литературоведческого и культурологического анализа показано, как основные мировоззренческие концепты fin de siècle нашли свое отражение в поэзии Ницше. Она представляется и как парафраз к его философии, и как самостоятельная творческий элемент, уловивший «дух времени»
The role of the state in the formation of a qualitative level of human capital in the Republic of Belarus
The article considers the theoretical aspects of the "human resource" concept, analyzes the approach to the formation of the human capital of the labour resources, the role of the state in the formation of the human capital of the workers
Exchange Risk Hedging When Carrying Out Exchange Operations
The article analyses the problems caused by the establishment of a floating market exchange rate regime in the Republic of Belarus. The liberalization of the currency market makes it necessary to use the strategies of risk hedging due to unfavorable changes in the exchange rate dynamics
The native architecture of a photosynthetic membrane
In photosynthesis, the harvesting of solar energy and its subsequent conversion into a stable charge separation are dependent upon an interconnected macromolecular network of membrane-associated chlorophyll–protein complexes. Although the detailed structure of each complex has been determined, the size and organization of this network are unknown. Here we show the use of atomic force microscopy to directly reveal a native bacterial photosynthetic membrane. This first view of any multi-component membrane shows the relative positions and associations of the photosynthetic complexes and reveals crucial new features of the organization of the network: we found that the membrane is divided into specialized domains each with a different network organization and in which one type of complex predominates. Two types of organization were found for the peripheral light-harvesting LH2 complex. In the first, groups of 10–20 molecules of LH2 form light-capture domains that interconnect linear arrays of dimers of core reaction centre (RC)–light-harvesting 1 (RC–LH1–PufX) complexes; in the second they were found outside these arrays in larger clusters. The LH1 complex is ideally positioned to function as an energy collection hub, temporarily storing it before transfer to the RC where photochemistry occurs: the elegant economy of the photosynthetic membrane is demonstrated by the close packing of these linear arrays, which are often only separated by narrow 'energy conduits' of LH2 just two or three complexes wide
Influence of subunit structure on the oligomerization state of light harvesting complexes: a free energy calculation study
Light harvesting complexes 2 (LH2) from Rhodospirillum (Rs.) molischianum and
Rhodopseudomonas (Rps.) acidophila form ring complexes out of eight or nine
identical subunits, respectively. Here, we investigate computationally what
factors govern the different ring sizes. Starting from the crystal structure
geometries, we embed two subunits of each species into their native
lipid-bilayer/water environment. Using molecular dynamics simulations with
umbrella sampling and steered molecular dynamics, we probe the free energy
profiles along two reaction coordinates, the angle and the distance between two
subunits. We find that two subunits prefer to arrange at distinctly different
angles, depending on the species, at about 42.5 deg for Rs. molischianum and at
about 38.5 deg for Rps. acidophila, which is likely to be an important factor
contributing to the assembly into different ring sizes. Our calculations
suggest a key role of surface contacts within the transmembrane domain in
constraining these angles, whereas the strongest interactions stabilizing the
subunit dimers are found in the C-, and to a lesser extent, N-terminal domains.
The presented computational approach provides a promising starting point to
investigate the factors contributing to the assembly of protein complexes, in
particular if combined with modeling of genetic variants.Comment: 28 pages, 7 figures, LaTeX2e - requires elsart.cls (included),
submitted to Chemical Physic
Self-assembled monolayer of light-harvesting core complexes of photosynthetic bacteria on an amino-terminated ITO electrode
Light-harvesting antenna core (LH1-RC) complexes isolated from Rhodospirillum rubrum and Rhodopseudomonas palustris were successfully self-assembled on an ITO electrode modified with 3-aminopropyltriethoxysilane. Near infra-red (NIR) absorption, fluorescence, and IR spectra of these LH1-RC complexes indicated that these LH1-RC complexes on the electrode were stable on the electrode. An efficient energy transfer and photocurrent responses of these LH1-RC complexes on the electrode were observed upon illumination of the LH1 complex at 880 nm
Integration of energy and electron transfer processes in the photosynthetic membrane of Rhodobacter sphaeroides
Photosynthesis converts absorbed solar energy to a protonmotive force, which drives ATP synthesis. The membrane network of chlorophyll–protein complexes responsible for light absorption, photochemistry and quinol (QH2) production has been mapped in the purple phototrophic bacterium Rhodobacter (Rba.) sphaeroides using atomic force microscopy (AFM), but the membrane location of the cytochrome bc1 (cytbc1) complexes that oxidise QH2 to quinone (Q) to generate a protonmotive force is unknown. We labelled cytbc1 complexes with gold nanobeads, each attached by a Histidine10 (His10)-tag to the C-terminus of cytc1. Electron microscopy (EM) of negatively stained chromatophore vesicles showed that the majority of the cytbc1 complexes occur as dimers in the membrane. The cytbc1 complexes appeared to be adjacent to reaction centre light-harvesting 1-PufX (RC–LH1–PufX) complexes, consistent with AFM topographs of a gold-labelled membrane. His-tagged cytbc1 complexes were retrieved from chromatophores partially solubilised by detergent; RC–LH1–PufX complexes tended to co-purify with cytbc1 whereas LH2 complexes became detached, consistent with clusters of cytbc1 complexes close to RC–LH1–PufX arrays, but not with a fixed, stoichiometric cytbc1–RC–LH1–PufX supercomplex. This information was combined with a quantitative mass spectrometry (MS) analysis of the RC, cytbc1, ATP synthase, cytaa3 and cytcbb3 membrane protein complexes, to construct an atomic-level model of a chromatophore vesicle comprising 67 LH2 complexes, 11 LH1–RC–PufX dimers & 2 RC–LH1–PufX monomers, 4 cytbc1 dimers and 2 ATP synthases. Simulation of the interconnected energy, electron and proton transfer processes showed a half-maximal ATP turnover rate for a light intensity equivalent to only 1% of bright sunlight. Thus, the photosystem architecture of the chromatophore is optimised for growth at low light intensities
- …