Temporal and spatial evolution of various functional neurons during demyelination induced by cuprizone

Multiple sclerosis (MS) is an inflammatory, demyelinating, and neurodegenerative disease of the central nervous system (CNS). Here, we reported the temporal and spatial evolution of various functional neurons during demyelination in a cuprizone (CPZ)-induced mouse model. CPZ did not significantly induce the damage of axons and neurons after 2 weeks of feeding. However, after 4-6 weeks of CPZ feeding, axons and neurons were markedly reduced in the cortex, posterior thalamic nuclear group, and hippocampus. Simultaneously, the expression of TPH+ tryptophan neurons and VGLUT1+ glutamate neurons was obviously decreased, and the expression of TH+ dopaminergic neurons was slightly decreased in the tail part of the substantia nigra striatum, while the number of ChAT+ cholinergic neurons was not significantly different in the brain. In the second week of feeding, CPZ caused a higher level of glutamate secretion and up-regulated the expression of EAAT2 on astrocytes, which should contribute to rapid and sufficient glutamate uptake and removal. This finding reveals that astrocyte-driven glutamate retake protected the CNS from excitotoxicity by rapid re-uptake of glutamate in 4-6 weeks of CPZ feeding. At this stage, although NG2+ oligodendroglia progenitor cells (OPCs) were enhanced in the demyelination foci, the myelin sheath was still absent. In conclusion, we comprehensively observed the temporal and spatial evolution of various functional neurons. Our results will assist with understanding how demyelination affects neurons during CPZ-induced demyelination and provides novel information for neuroprotection in myelin regeneration and demyelinating diseases.

A Phylogenetic Approach to Structural Variation in Organization of Nuclear Group I Introns and Their Ribozymes

Nuclear group I introns are restricted to the ribosomal DNA locus where they interrupt genes for small subunit and large subunit ribosomal RNAs at conserved sites in some eukaryotic microorganisms. Here, the myxomycete protists are a frequent source of nuclear group I introns due to their unique life strategy and a billion years of separate evolution. The ribosomal DNA of the myxomycete Mucilago crustacea was investigated and found to contain seven group I introns, including a direct repeat-containing intron at insertion site S1389 in the small subunit ribosomal RNA gene. We collected, analyzed, and compared 72 S1389 group IC1 introns representing diverse myxomycete taxa. The consensus secondary structure revealed a conserved ribozyme core, but with surprising sequence variations in the guanosine binding site in segment P7. Some S1389 introns harbored large extension sequences in the peripheral region of segment P9 containing direct repeat arrays. These repeats contained up to 52 copies of a putative internal guide sequence motif. Other S1389 introns harbored homing endonuclease genes in segment P1 encoding His-Cys proteins. Homing endonuclease genes were further interrupted by small spliceosomal introns that have to be removed in order to generate the open reading frames. Phylogenetic analyses of S1389 intron and host gene indicated both vertical and horizontal intron transfer during evolution, and revealed sporadic appearances of direct repeats, homing endonuclease genes, and guanosine binding site variants among the myxomycete taxa.

The Nunn-Lugar Program and Nuclear Disarmament of Ukraine

This article is devoted to studying the process of nuclear disarmament of Ukraine in the framework of the Nunn-Lugar Program in the first half of the 1990s. The reconstruction of this process makes it possible to determine specific features of the Ukrainian disarmament and demonstrate the absence of alternatives for it. Methods and materials. The paper is based on the latest U.S. declassified documents, regulatory and legal acts, memoirs, etc. The author uses historical and systemic methods to research the stages of the evolution of the nuclear disarmament process in Ukraine and study politicians attitudes towards the Soviet nuclear legacy. Analysis and results. The study investigates the reasons for joining the efforts of Moscow and Washington in turning Ukraine into a “nuclear-free state”, reveals the Russian and American attitudes towards the problem. Particular attention is paid to contradictions within the Ukrainian political elite that was split into the “pro-nuclear” and “antinuclear” groups. The article also studies the role of President L. Kravchuk in solving the disarmament problem, which was extremely contradictory. Finally, the article analyzes the reasons that allow to change the balance of political forces in Ukraine in favor of the “anti-nuclear” group, which enabled president Kravchuk to reaffirm his international obligations and initiate the nuclear disarmament process. In general, the article shows that the preservation of nuclear weapons by Ukraine was impossible due to a number of financial, technological, and geopolitical reasons.

Nauruan classification

Nauruan is a Micronesian language that has been classified outside of the Nuclear Micronesian group. This classification suggests that Nauruan, unlike all other Micronesian languages, did not descend from Proto-Micronesian. Though this view has been adopted in the literature, it should be considered tenuous. It is based on little Nauruan data and is informed by work that is presented as highly tentative. This paper presents a reassessment of Nauruan classification, drawing on data from original fieldwork. Research shows not only that Nauruan is a Micronesian language, but that there is no compelling evidence for classifying Nauruan apart from the Nuclear group. Of particular importance is the claim that Nauruan fails to reflect the merger of Proto-Oceanic *d and *dr as Proto-Micronesian *c (Jackson 1986). Comparative evidence suggests that Nauruan does reflect this merger: POc *d, *dr > PMc *c > ř. It follows that Jackson's classification for Nauruan is unmotivated, as is the Nuclear/non-Nuclear distinction within the family. Having established that Nauruan need not be classified apart from the Nuclear group, Nauruan's precise classification within the Micronesian family is considered. A question of primary importance is whether Nauruan reflects the merger of Proto-Micronesian *s and *S. The possibility that Nauruan did not participate in this merger is considered, in which case Nauruan should be classified outside of the Central Micronesian group, like Kosraean. The possibility that Nauruan did participate in this merger is also considered, in which case Nauruan should be classified somewhere within Central Micronesian. Further, some innovations are described which are potentially shared between Nauruan and certain Central Micronesian languages. The possibility that these are shared innovations is considered, as are the implications this would have for Nauruan classification.

Uranium price recovery has limited upside

Subject Uranium prices and nuclear power. Significance The price of uranium breached 25 dollars per pound this month for the first time since last August. Boosted by Kazakhstan, the source of 41% of global uranium supplies, announcing last month that it will reduce production by 10% in 2017, the metal's price has been gradually recovering from last November's twelve-year low of 18 dollars per pound. However, the market remains oversupplied. Impacts Brexit may leave the UK nuclear sector without a regulator and short of fuel (21% of UK electricity generation is nuclear). Vietnam has abandoned its long-delayed plan to build its first nuclear power plant. South Africa has started a procurement programme to add 9.6 gigawatts of nuclear capacity. The EU has approved the 4.5-billion-euro (4.8-billion-dollar) restructuring plan of the French nuclear group Areva.

Morphology and phylogeny of three karyorelictean ciliates (Protista, Ciliophora), including two novel species, Trachelocerca chinensis sp. n. and Tracheloraphis dragescoi sp. n.

This paper investigates the morphology and infraciliature of three karyorelictean ciliates, Trachelocerca chinensis sp. n., Tracheloraphis dragescoi sp. n. and a rarely known form, Geleia acuta (Dragesco, 1960) Foissner, 1998, which were isolated from the intertidal zone of sandy beaches at Zhanjiang and Qingdao, China. Trachelocerca chinensis sp. n. is distinguished from related forms by having 26–30 somatic kineties, a narrow glabrous stripe and a single nuclear group composed of approximately four to six macronuclei and two micronuclei. Tracheloraphis dragescoi sp. n. can be recognized through its 14–22 somatic kineties, wide glabrous stripe and a single nuclear group composed of about four macronuclei. Phylogenetic analyses based on small-subunit (SSU) rRNA gene sequences indicated that the genera Trachelocerca and Tracheloraphis are closely related but that neither of them appears to be a clearly monophyletic group. Nonetheless, the monophyly of Trachelocerca is not rejected by the approximately unbiased (AU) test (P = 0.143, >0.05), although that of Tracheloraphis is rejected (P = 0.011, <0.05). Geleia acuta, meanwhile, branched with Geleia fossata and falls in the Geleia clade.