Mlig-SKP1 Gene Is Required for Spermatogenesis in the Flatworm Macrostomum lignano

In a free-living flatworm, Macrostomum lignano, an S-phase kinase-associated protein 1 (SKP1) homologous gene was identified as enriched in proliferating cells, suggesting that it can function in the regulation of stem cells or germline cells since these are the only two types of proliferating cells in flatworms. SKP1 is a conserved protein that plays a role in ubiquitination processes as a part of the Skp1-Cullin 1-F-box (SCF) ubiquitin ligase complex. However, the exact role of Mlig-SKP1 in M. lignano was not established. Here, we demonstrate that Mlig-SKP1 is neither involved in stem cell regulation during homeostasis, nor in regeneration, but is required for spermatogenesis. Mlig-SKP1(RNAi) animals have increased testes size and decreased fertility as a result of the aberrant maturation of sperm cells. Our findings reinforce the role of ubiquitination pathways in germ cell regulation and demonstrate the conserved role of SKP1 in spermatogenesis.     

Possibility of Building a Thermal Nuclear Reactor with Total Utilization of the Initial Uranium and Thorium

It is shown that total utilization of the natural stocks of uranium and thorium is possible in thermal nuclear reactors. The technology is based on eliminating parasitic neutron absorption in ¹³⁵Xe, using cyclic operation of the fuel elements in the reactor. In addition, neutron losses in the production chains of fissioning materials are smaller and fissioning materials, especially ²³³U, are put into active operation more quickly. The advantages of cyclic transposition can be fully realized by using the core superposition method. In this method, the excess neutrons from a part of the core where the reactivity is positive are directed into a zone with a high breeding ratio and negative reactivity.Fuel based on natural uranium permits using up to 18% of the initial material with recycling. Adding more than 20% ²³²Th to the initial material permits total utilization of ²³²Th and ²³⁸U in the recycling regime.     

Tests on a setup with natural circulation of LiF-BeF2-UF4 liquid-salt fuel

Translated from Atomnaya Énergiya, Vol. 69, No. 4, pp. 211–215, October, 1990.     

Prion‐associated proteins in yeast: comparative analysis of isogenic [PSI+] and [psi−] strains

A large group of prion‐associated proteins was identified in yeast cells using a new approach, comparative analysis of pellet proteins of crude cell lysates in isogenic strains of Saccharomyces cerevisiae differing by their prion composition. Two‐dimensional (2D) electrophoresis followed by MALDI analysis of the pellet proteins of [PSI⁺] and [psi^?] strains after prion elimination by GuHCl and prion transmission by cytoduction permitted identification of ca. 40 proteins whose aggregation state correlated with the change of prion(s) content. Approximately half of these proteins belonged to chaperones and to enzymes of glucose metabolism. Chaperones are known to be involved in prion metabolism and are expected to be present in prion‐containing aggregates, but glucose metabolism enzymes are not predicted to be present. Nevertheless, several recent data suggest that their presence is not incidental. We detected six proteins involved in oxidative stress response and eight in translation. Also notable is a protease. Most of the identified proteins seem to be prion‐associated, but we cannot exclude the possibility that several proteins may propagate as prions. Copyright © 2009 John Wiley & Sons, Ltd.     

Diagnosis of breakdowns in the state of a technological process based on graphic-analytical methods of situation analysis

Conclusions General principles for construction and analysis of a structural graph of a diagnostic system for breakdowns in technological processes in the ACS TP for artificial fibre manufacturing plants have been examined.Approaches have been given to the performance of a diagnostic search, founded on the application of formal models and graphic-analytical methods of analysis.Procedures for realizing a system of diagnosis of breakdowns in technological processes have been examined in the case of solving this problem in the make-up of ACS TP for cellophane manufacture in the Kiev Khimvolokno PO.Translated from Khimicheskie Volokna, No. 5, pp. 39–43, September–October, 1986.