Discrete foci containing RNase A are found in nucleoli of HeLa cells aged in culture

We have studied by means of ultrastructural immunocytochemistry the localization of RNase A in nuclei of HeLa cells in control conditions and following cell ageing in culture. We have found that roundish, electron dense foci, which contain a significant amount of RNase A, can be detected within nucleoli of aged cells. These bodies also contain RNA and lack ribosomal S3 proteins, and may represent either simple storage sites or areas where RNA degradation takes place

Involvement of the specific nucleolar protein SURF6 in regulation of proliferation and ribosome biogenesis in mouse NIH/3T3 fibroblasts

The nucleolar proteins which link cell proliferation to ribosome biogenesis are regarded to be potentially oncogenic. Here, in order to examine the involvement of an evolutionary conserved nucleolar protein SURF6/Rrp14 in proliferation and ribosome biogenesis in mammalian cells, we established stably transfected mouse NIH/3T3 fibroblasts capable of conditional overexpression of the protein. Cell proliferation was monitored in real-time, and various cell cycle parameters were quantified based on flow cytometry, Br-dU-labeling and conventional microscopy data. We show that overexpression of SURF6 accelerates cell proliferation and promotes transition through all cell cycle phases. The most prominent SURF6 pro-proliferative effects include a significant reduction of the population doubling time, from 19.8±0.7 to 16.2±0.5 hours (t-test, p<0.001), and of the length of cell division cycle, from 17.6±0.6 to 14.0±0.4 hours (t-test, p<0.001). The later was due to the shortening of all cell cycle phases but the length of G1 period was reduced most, from 5.7 ±0.4 to 3.8 ±0.3 hours, or by ∼30%, (t-test, p<0.05). By Northern blots and qRT-PCR, we further showed that the acceleration of cell proliferation was concomitant with an accumulation of rRNA species along both ribosomal subunit maturation pathways. It is evident, therefore, that like the yeast homologue Rrp14, mammalian SURF6 is involved in various steps of rRNA processing during ribosome biogenesis. We concluded that SURF6 is a novel positive regulator of proliferation and G1/S transition in mammals, implicating that SURF6 is a potential oncogenic protein, which can be further studied as a putative target in anti-cancer therapy

Neural network ChatGPT: a helping hand or a new competitor?

Since artificial intelligence attracts more attention in recent years, we analyzed one of the most advanced neural networks called Chat GPT. It was determined that neural networks are a type of artificial intelligence that simulate the work of the human brain and constantly adapt to new data inputs in order to become more efficient. The history, types and examples of neural networks are mentioned. The GPT-2 Output Detector which was developed to detect fake news and biased information generated by AI was described. The working principles of Chat GPT, benefits and risks connected with the use of this neural network are given in details. Different prospects of Chat GPT development are proposed

Xenobiotic-induced activation of human aryl hydrocarbon receptor target genes in Drosophila is mediated by the epigenetic chromatin modifiers

Aryl hydrocarbon receptor (AHR) is the key transcription factor that controls animal development and various adaptive processes. The AHR\u27s target genes are involved in biodegradation of endogenous and exogenous toxins, regulation of immune response, organogenesis, and neurogenesis. Ligand binding is important for the activation of the AHR signaling pathway. Invertebrate AHR homologs are activated by endogenous ligands whereas vertebrate AHR can be activated by both endogenous and exogenous ligands (xenobiotics). Several studies using mammalian cultured cells have demonstrated that transcription of the AHR target genes can be activated by exogenous AHR ligands, but little is known about the effects of AHR in a living organism. Here, we examined the effects of human AHR and its ligands using transgenic Drosophila lines with an inducible human AhR gene. We found that exogenous AHR ligands can increase as well as decrease the transcription levels of the AHR target genes, including genes that control proliferation, motility, polarization, and programmed cell death. This suggests that AHR activation may affect the expression of gene networks that could be critical for cancer progression and metastasis. Importantly, we found that AHR target genes are also controlled by the enzymes that modify chromatin structure, in particular components of the epigenetic Polycomb Repressive complexes 1 and 2. Since exogenous AHR ligands (alternatively - xenobiotics) and small molecule inhibitors of epigenetic modifiers are often used as pharmaceutical anticancer drugs, our findings may have significant implications in designing new combinations of therapeutic treatments for oncological diseases. © Akishina et al

Conditions and technologies of students ecological culture formation

© Authors. Technical progress is closely connected with the social and everyday comfort of society, with the level of the needs of modern society, but the disruption of production cycles, the low level of environmental management culture, the unintelligible consequences of its power over the surrounding world, destroy the harmony of the environment and human beings. The purpose of the paper is directed to improve the professional training of graduates of higher educational institutions, capable of solving production problems with minimizing environmental risks. The authors revealed pedagogical approaches to environmental education and substantiated the essence of the concept "ecological culture of students". Pedagogical conditions that contribute to the formation of ecological culture of university students are developed, introduced and experimental tested. The paper is intended for teachers, heads of educational organizations, researchers dealing with environmental security issues

Didactic principles of university information educational systems designing

© Authors. The attention of all parts of perspective education system should be focused on promising information technologies - a catalyst for development. Presenting information as a new resource for society development, the authors determine the didactic basis for designing effective information educational systems. Universal didactic principles for information educational systems design have been developed, the details of which for discipline and for the subject adapt them to the university organizational and pedagogical conditions. The pedagogical management functions in modern educational conditions that determine the students' motivation and stimulation initiation mechanism for mastering a knowledge new system to develop the individual's creative abilities, self-development are revealed. The paper is intended for researchers, teachers, and specialists in the field of information educational technologies

Combination of hypomorphic mutations of the Drosophila homologues of aryl hydrocarbon receptor and nucleosome assembly protein family genes disrupts morphogenesis, memory and detoxification

Aryl hydrocarbon receptor is essential for biological responses to endogenous and exogenous toxins in mammals. Its Drosophila homolog spineless plays an important role in fly morphogenesis. We have previously shown that during morphogenesis spineless genetically interacts with CG5017 gene, which encodes a nucleosome assembly factor and may affect cognitive function of the fly. We now demonstrate synergistic interactions of spineless and CG5017 in pathways controlling oxidative stress response and long-term memory formation in Drosophila melanogaster. Oxidative stress was induced by low doses of X-ray irradiation of flies carrying hypomorphic mutation of spineless, mutation of CG5017, and their combination. To determine the sensitivity of these mutants to pharmacological modifiers of the irradiation effect, we irradiated flies growing on standard medium supplemented by radiosensitizer furazidin and radioprotector serotonin. The effects of irradiation were investigated by analyzing leg and antenna morphological structures and by using real-time PCR to measure mRNA expression levels for spineless, Cyp6g1 and Gst-theta genes. We also examined long-term memory in these mutants using conditioned courtship suppression paradigm. Our results show that the interaction of spineless and CG5017 is important for regulation of morphogenesis, long-term memory formation, and detoxification during oxidative stress. Since spineless and CG5017 are evolutionary conserved, these results must be considered when evaluating the risk of combining similar mutations in other organisms, including humans

Ferro-electric phase transition in a polar liquid and the nature of \lambda-transition in supercooled water

We develop a series of approximations to calculate free energy of a polar liquid. We show that long range nature of dipole interactions between the molecules leads to para-electric state instability at low temperatures and to a second-order phase transition. We establish the transition temperature, T_{c}, both within mean field and ring diagrams approximation and show that the ferro-electric transition may play an important role explaining a number of peculiar properties of supercooled water, such as weak singularity of dielectric constant as well as to a large extent anomalous density behavior. Finally we discuss the role of fluctuations, shorter range forces and establish connections with phenomenological models of polar liquids.Comment: 5 pages, 1 eps figure, density anomaly at T=4C analysis adde

Medicine and improvement in the Scots Magazine; and Edinburgh Literary Miscellany, 1804-17

Megan Coyer’s chapter engages with periodical print as a vehicle for an improving medical culture in Scotland, concentrating on the second series of the Scots Magazine. Coyer demonstrates how the Scottish press often complemented improving civic initiatives like the Edinburgh Lunatic Asylum campaign. She focuses attention on the distinctive national dynamics associated with medical improvement efforts in early nineteenth-century Scotland, with the Scots Magazine ‘providing a public forum for the expression of a national medical identity’. This identity, as Coyer shows, had an ideology of improvement at its core. This work recovers the cultural significance of the Scots Magazine as ‘the third major player in popular periodical culture in Romantic-era Scotland’; a status overshadowed by the recent critical attention devoted to the second Edinburgh Review and Blackwood’s in Scottish Romantic studies. Coyer also shows how the efforts of public health reformers highlight the complexity of improvement as both a material and moral process. She argues that print efforts dedicated to improving public health represent a ‘discursive strand in the magazine identifying a lack of cleanliness … as a moral and material blight on an otherwise improving Scottish society’. This bringing together of moral and practical aspects of improvement in the Scots also finds expression in the magazine’s series of Scottish medical biographies, whose narratives, Coyer notes, provide ‘ideal exemplars of lives dedicated to a culture of improvement’

Nucleologenesis in the Caenorhabditis elegans Embryo

In the Caenorhabditis elegans nematode, the oocyte nucleolus disappears prior to fertilization. We have now investigated the re-formation of the nucleolus in the early embryo of this model organism by immunostaining for fibrillarin and DAO-5, a putative NOLC1/Nopp140 homolog involved in ribosome assembly. We find that labeled nucleoli first appear in somatic cells at around the 8-cell stage, at a time when transcription of the embryonic genome begins. Quantitative analysis of radial positioning showed the nucleolus to be localized at the nuclear periphery in a majority of early embryonic nuclei. At the ultrastructural level, the embryonic nucleolus appears to be composed of a relatively homogenous core surrounded by a crescent-shaped granular structure. Prior to embryonic genome activation, fibrillarin and DAO-5 staining is seen in numerous small nucleoplasmic foci. This staining pattern persists in the germline up to the ∼100-cell stage, until the P4 germ cell divides to give rise to the Z2/Z3 primordial germ cells and embryonic transcription is activated in this lineage. In the ncl-1 mutant, which is characterized by increased transcription of rDNA, DAO-5-labeled nucleoli are already present at the 2-cell stage. Our results suggest a link between the activation of transcription and the initial formation of nucleoli in the C. elegans embryo