Antagonistic Effects of Point Mutations on Charge Recombination and a New View of Primary Charge Separation in Photosynthetic Proteins

[Image: see text] Light-induced electron-transfer reactions were investigated in wild-type and three mutant Rhodobacter sphaeroides reaction centers with the secondary electron acceptor (ubiquinone Q(A)) either removed or permanently reduced. Under such conditions, charge separation between the primary electron donor (bacteriochlorophyll dimer, P) and the electron acceptor (bacteriopheophytin, H(A)) was followed by P(+)H(A)(–) → PH(A) charge recombination. Two reaction centers were used that had different single amino-acid mutations that brought about either a 3-fold acceleration in charge recombination compared to that in the wild-type protein, or a 3-fold deceleration. In a third mutant in which the two single amino-acid mutations were combined, charge recombination was similar to that in the wild type. In all cases, data from transient absorption measurements were analyzed using similar models. The modeling included the energetic relaxation of the charge-separated states caused by protein dynamics and evidenced the appearance of an intermediate charge-separated state, P(+)B(A)(–), with B(A) being the bacteriochlorophyll located between P and H(A). In all cases, mixing of the states P(+)B(A)(–) and P(+)H(A)(–) was observed and explained in terms of electron delocalization over B(A) and H(A). This delocalization, together with picosecond protein relaxation, underlies a new view of primary charge separation in photosynthesis

Energy independence and financial stability of economic entities in the conditions of war

Russia’s invasion of Ukraine has caused many social, economic, environmental and energy problems. Most business entities faced problems at the national level that affected their financial and economic activities. The mass departure of workers abroad, rising natural gas prices, internal relocation, and constant shelling force business entities to search for new approaches to the management and development of their enterprises. The purpose of the study – substantiate and test the scientific and methodological approach to achieving energy independence of economic entities as a way to avoid their insolvency in times of war. In the course of the study, a critical analysis of the thematic literature was performed, and a set of general scientific and special research methods was used: expert assessments, observation, analogy, grouping, obtaining a consensus, deductive, inductive reasoning, systematisation, system-functional, measurement, analysis, comparison, logical generalisation, systematisation, hypothesis, a repeated combination of independent scenarios, extrapolation, elasticity estimation and graphical. The study identified the consequences of the military invasion of Ukraine and developed an algorithm for actions during the war. Four scenarios have been identified, under which the investigated business entity can solve the urgent problems. It is substantiated that the best scenario is the one in which it is required to increase its production capacity by setting up a “full cycle” production using a continuous pyrolysis system for the recycling of worn-out tires. The rationality of its use is proved. The scientific and methodological tools for interaction between business entities and the state during the war have been improved based on a systematic approach, which, unlike the existing ones, deepens the significance of shifting the centre of gravity from the macro to the micro level and is based on the proposed algorithm of actions (identifying the problem, developing possible scenarios for its immediate solution, compliance of the chosen scenario with the national interests of the state, finding a source of funding for the implementation of one of the scenarios), which determines the most optimistic scenario of the balance of interests between the state and business entities. The practical value of the proposed lies in the identification of economic, social, environmental and energy efficiency of the developed algorithm of actions in practice, on the example of financial and economic activities of the entity. Such an approach, on the one hand, allows for achieving energy independence soon and is a way to avoid the insolvency of economic entities in the conditions of war. On the other hand, it should become a reliable base for the national economy in the period of post-war reconstructio

Methodology for the assessment of forestry competitiveness in Ukraine

Considering the economic, social and environmental potential of the forestry sector of Ukraine, and the rather low level of its efficiency, an important task is to create conditions for the competitive development of the forestry industry. A precondition for such development is an objective assessment of the regional competitiveness of forestry complexes, which requires the elaboration of appropriate methodological and methodological approaches. The regional approach to competitiveness assessment ensures that the specific features of all natural zones on the territory of Ukraine, characterised by different soil and climatic conditions and unequal forest cover, are taken into account. The purpose of this study is to substantiate and test methodological and methodological approaches to assessing the competitiveness of forestry in Ukraine. The methodological basis of the research was the methods of analysis and synthesis, system generalisation and dialectical method. Methodological and methodical approaches to the assessment of the competitiveness of forestry in Ukraine are substantiated. The main challenges of forestry enterprises that form the potential of the industry are identified. The factors that form the level of competitiveness of forestry are highlighted. Positive and negative trends in the competitive development of regional forestry complexes are identified. Based on the assessment of the competitiveness of forestry complexes, their classification in the major natural zones of Ukraine was completed. The conducted research will serve as a basis for assessing the efficiency of individual forestry enterprises in the context of strengthening their competitiveness. The main advantages (disadvantages) of competitive development of business entities can become an objective prerequisite for making appropriate management decision

ЕКОНОМІКО–ПРАВОВІ ТА ФІНАНСОВІ АСПЕКТИ РОЗВИТКУ НАЦІОНАЛЬНОГО ГОСПОДАРСТВА УКРАЇНИ: УПРАВЛІННЯ ЕФЕКТИВНІСТЮ ТА РЕЗУЛЬТАТИВНІСТЮ

The article analyzes the state and prospects of development of the national economy of Ukraine; Certain priority directions of development of certain sectors of the economy of Ukraine are envisaged, which envisage realization of concrete measures and implementation of numerous factors of social, political and economic aspects; Analyzed the statistics over the past five years and revealed a significant number of loss–making enterprises, indicating unfavorable economic conditions in the country, in particular: rapid depreciation of the national currency, rising inflation, declining household incomes, decreasing income and bank loans; Unsatisfactory state and prospects of investment attractiveness of Ukraine, etc. The observed tendency of the next financial crisis in the country due to the existing economic, social and political problems in the country is the level of legislative support and regulation of economic, administrative and legal relations in the process of financial and economic activity, which gives grounds for a scientific statement on the influence of criminal– Legal factors on the growth (in this case, the fall) of the national economy and the welfare of the Ukrainian population. The necessity of creation of such a legislative base, which would drastically improve the investment and legal climate in the country, has allowed to increase volumes of both domestic and foreign investments, which would have an effective influence on overcoming the crisis in the Ukrainian economy and socio–economic potential of the society.В статье исследованы состояние и перспективы развития национального хазяйства Украины на примере статистических данных; законодательное урегулирование хозяйственных, административных и правових отношений в процессе финансово–экономической деятельности. Обоснованы научные утверждения относительно влияния криминально–правовых факторов на рост (падение) национальной экономики и благосостояния населения Украины.У статті досліджені стан та перспективи розвитку національного господарства України на прикладі статистичних даних; законодавче врегулювання господарських, адміністративних та правових відносин у процесі фінансово–економічної діяльності. Обгрунтовано наукові твердження щодо впливу кримінально–правових факторів на зростання (падіння) національної економіки та добробуту населення України.

The Nature of Ultra-Luminous Compact X-Ray Sources in Nearby Spiral Galaxies

Studies were made of ASCA spectra of seven ultra-luminous compact X-ray sources (ULXs) in nearby spiral galaxies; M33 X-8 (Takano et al. 1994), M81 X-6 (Fabbiano 1988b; Kohmura et al. 1994; Uno 1997), IC 342 Source 1 (Okada et al. 1998), Dwingeloo 1 X-1 (Reynolds et al. 1997), NGC 1313 Source B (Fabbiano & Trinchieri 1987; Petre et al. 1994), and two sources in NGC 4565 (Mizuno et al. 1999). With the 0.5--10 keV luminosities in the range 10^{39-40} ergs/s, they are thought to represent a class of enigmatic X-ray sources often found in spiral galaxies. For some of them, the ASCA data are newly processed, or the published spectra are reanalyzed. For others, the published results are quoted. The ASCA spectra of all these seven sources have been described successfully with so called multi-color disk blackbody (MCD) emission arising from optically-thick standard accretion disks around black holes. Except the case of M33 X-8, the spectra do not exhibit hard tails. For the source luminosities not to exceed the Eddington limits, the black holes are inferred to have rather high masses, up to ~100 solar masses. However, the observed innermost disk temperatures of these objects, Tin = 1.1--1.8 keV, are too high to be compatible with the required high black-hole masses, as long as the standard accretion disks around Schwarzschild black holes are assumed. Similarly high disk temperatures are also observed from two Galactic transients with superluminal motions, GRO 1655-40 and GRS 1915+105. The issue of unusually high disk temperature may be explained by the black hole rotation, which makes the disk get closer to the black hole, and hence hotter.Comment: submitted to ApJ, December 199

Regeneration of zygotic-like microspore-derived embryos suggests an important role for the suspensor in early embryo patterning

Plant science

Freely Suspended Cellular “Backpacks” Lead to Cell Aggregate Self-Assembly

Cellular “backpacks” are a new type of anisotropic, nanoscale thickness microparticle that may be attached to the surface of living cells creating a “bio-hybrid” material. Previous work has shown that these backpacks do not impair cell viability or native functions such as migration in a B and T cell line, respectively. In the current work, we show that backpacks, when added to a cell suspension, assemble cells into aggregates of reproducible size. We investigate the efficiency of backpack−cell binding using flow cytometry and laser diffraction, examine the influence of backpack diameter on aggregate size, and show that even when cell−backpack complexes are forced through small pores, backpacks are not removed from the surfaces of cells.National Science Foundation (U.S.). Materials Research Science and Engineering Centers (Program) (Award DMR-08-19762)National Science Foundation (U.S.) (Graduate Research Fellowship)United States. Dept. of DefenseUnited States. Air Force Office of Scientific ResearchHoward Hughes Medical Institute (Investigator)United States. Dept. of Defense (National Defense Science and Engineering Graduate Fellowship 32 CFR 168a

Microtubule configurations and nuclear DNA synthesis during initiation of suspensor-bearing embryos from Brassica napus cv. Topas microspores

In the new Brassica napus microspore culture system, wherein embryos with suspensors are formed, ab initio mimics zygotic embryogenesis. The system provides a powerful in vitro tool for studying the diverse developmental processes that take place during early stages of plant embryogenesis. Here, we studied in this new culture system both the temporal and spatial distribution of nuclear DNA synthesis places and the organization of the microtubular (MT) cytoskeleton, which were visualized with a refined whole mount immunolocalization technology and 3D confocal laser scanning microscopy. A ‘mild’ heat stress induced microspores to elongate, to rearrange their MT cytoskeleton and to re-enter the cell cycle and perform a predictable sequence of divisions. These events led to the formation of a filamentous suspensor-like structure, of which the distal tip cell gave rise to the embryo proper. Cells of the developing pro-embryo characterized endoplasmic (EMTs) and cortical microtubules (CMTs) in various configurations in the successive stages of the cell cycle. However, the most prominent changes in MT configurations and nuclear DNA replication concerned the first sporophytic division occurring within microspores and the apical cell of the pro-embryo. Microspore embryogenesis was preceded by pre-prophase band formation and DNA synthesis. The apical cell of the pro-embryo exhibited a random organization of CMTs and, in relation to this, isotropic expansion occurred, mimicking the development of the apical cell of the zygotic situation. Moreover, the apical cell entered the S phase shortly before it divided transversally at the stage that the suspensor was 3–8 celled

Trajectories of Delinquency and Parenting Styles

We investigated trajectories of adolescent delinquent development using data from the Pittsburgh Youth Study and examined the extent to which these different trajectories are differentially predicted by childhood parenting styles. Based on self-reported and official delinquency seriousness, covering ages 10–19, we identified five distinct delinquency trajectories differing in both level and change in seriousness over time: a nondelinquent, minor persisting, moderate desisting, serious persisting, and serious desisting trajectory. More serious delinquents tended to more frequently engage in delinquency, and to report a higher proportion of theft. Proportionally, serious persistent delinquents were the most violent of all trajectory groups. Using cluster analysis we identified three parenting styles: authoritative, authoritarian (moderately supportive), and neglectful (punishing). Controlling for demographic characteristics and childhood delinquency, neglectful parenting was more frequent in moderate desisters, serious persisters, and serious desisters, suggesting that parenting styles differentiate non- or minor delinquents from more serious delinquents