104 research outputs found

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

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    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

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    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

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    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

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    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

    Интерстициальное заболевание легких, ассоциированное с системной склеродермией, у пациента с длительным стажем работы мраморщиком

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    Systemic sclerosis (SSc) is a disease characterized by vasculopathy, fibrosis of the skin and internal organs, most often complicated by interstitial lung disease (ILD). The incidence of SSc reaches 20 cases per 1 million population per year, while changes in the lungs are found in more than half of patients and are characterized by a rapid increase in fibrosis, poorly controlled respiratory failure, and an unfavorable prognosis. It is important to trace the features of the formation and course of ILD and its relationship with occupational hazards in patients diagnosed with SSc. Dust pathology of the respiratory organs (chronic dust bronchitis and silicosis) is most typical for people with long work experience in mining. Silicosis in these patients may be accompanied by SSc with rapid progression of bronchial obstruction, restrictive disorders, as well as myocardial involvement and the development of pulmonary hypertension.Системная склеродермия (ССД) – заболевание, характеризующееся васкулопатией, фиброзом кожи и внутренних органов и наиболее часто осложняющееся интерстициальным заболеванием легких (ИЗЛ). Заболеваемость ССД достигает 20 случаев на 1 млн населения в год, при этом изменения в легких обнаруживаются более чем у половины пациентов и отличаются быстротой нарастания фиброза, плохо контролируемой дыхательной недостаточностью и неблагоприятным прогнозом. Важно проследить особенности формирования и течения ИЗЛ и его связь с профессиональными вредностями у пациентов с диагнозом ССД. Пылевая патология органов дыхания (хронический пылевой бронхит и силикоз) наиболее характерны для людей с длительным стажем работы в отраслях горной промышленности. Силикоз у таких пациентов может сопровождаться ССД с быстрым прогрессированием бронхиальной обструкции, рестриктивных нарушений, а также поражением миокарда и развитием легочной гипертензии

    New Assembly, Reannotation and Analysis of the Entamoeba histolytica Genome Reveal New Genomic Features and Protein Content Information

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    Entamoeba histolytica is an anaerobic parasitic protozoan that causes amoebic dysentery. The parasites colonize the large intestine, but under some circumstances may invade the intestinal mucosa, enter the bloodstream and lead to the formation of abscesses such amoebic liver abscesses. The draft genome of E. histolytica, published in 2005, provided the scientific community with the first comprehensive view of the gene set for this parasite and important tools for elucidating the genetic basis of Entamoeba pathogenicity. Because complete genetic knowledge is critical for drug discovery and potential vaccine development for amoebiases, we have re-examined the original draft genome for E. histolytica. We have corrected the sequence assembly, improved the gene predictions and refreshed the functional gene assignments. As a result, this effort has led to a more accurate gene annotation, and the discovery of novel features, such as the presence of genome segmental duplications and the close association of some gene families with transposable elements. We believe that continuing efforts to improve genomic data will undoubtedly help to identify and characterize potential targets for amoebiasis control, as well as to contribute to a better understanding of genome evolution and pathogenesis for this parasite

    Ribosomal RNA of Hyacinthus orientalis L. female gametophyte cells before and after fertilization

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    The nucleolar activity of Hyacinthus orientalis L. embryo sac cells was investigated. The distributions of nascent pre-rRNA (ITS1), 26S rRNA and of the 5S rRNA and U3 snoRNA were determined using fluorescence in situ hybridization (FISH). Our results indicated the different rRNA metabolism of the H. orientalis female gametophyte cells before and after fertilization. In the target cells for the male gamete, i.e., the egg cell and the central cell whose activity is silenced in the mature embryo sac (Pięciński et al. in Sex Plant Reprod 21:247–257, 2008; Niedojadło et al. in Planta doi:10.1007/s00425-012-1599-9, 2011), rRNA metabolism is directed at the accumulation of rRNPs in the cytoplasm and immature transcripts in the nucleolus. In both cells, fertilization initiates the maturation of the maternal pre-rRNA and the expression of zygotic rDNA. The resumption of rRNA transcription observed in the hyacinth zygote indicates that in plants, there is a different mechanism for the regulation of RNA Pol I activity than in animals. In synergids and antipodal cells, which have somatic functions, the nucleolar activity is correlated with the metabolic activity of these cells and changes in successive stages of embryo sac development

    Contrasting Patterns of Transposable Element Insertions in Drosophila Heat-Shock Promoters

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    The proximal promoter regions of heat-shock genes harbor a remarkable number of P transposable element (TE) insertions relative to both positive and negative control proximal promoter regions in natural populations of Drosophila melanogaster. We have screened the sequenced genomes of 12 species of Drosophila to test whether this pattern is unique to these populations. In the 12 species' genomes, transposable element insertions are no more abundant in promoter regions of single-copy heat-shock genes than in promoters with similar or dissimilar architecture. Also, insertions appear randomly distributed across the promoter region, whereas insertions clustered near the transcription start site in promoters of single-copy heat-shock genes in D. melanogaster natural populations. Hsp70 promoters exhibit more TE insertions per promoter than all other genesets in the 12 species, similarly to in natural populations of D. melanogaster. Insertions in the Hsp70 promoter region, however, cluster away from the transcription start site in the 12 species, but near it in natural populations of D. melanogaster. These results suggest that D. melanogaster heat-shock promoters are unique in terms of their interaction with transposable elements, and confirm that Hsp70 promoters are distinctive in TE insertions across Drosophila

    Power-Supply Systems Reliability Control

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    System reliability control is proposed to maintain through the usage of the operating time between the system components' failure. Usually, trouble-free (reliability) is assessed considering component failures. Almost all the system probabilistic parameters were determined via the component failures. The system reliability control requires another approach to solve this kind of problem. The first thing is a rational system component selection, which is necessary to provide its reliable functioning in the process of exploitation, safe maintenance, cost-effective mounting and dismounting. Secondly, the components must meet technical and economic feasibility requirements. They cannot be used with high or low capacity. If the component capacity is overrated, you bear unjustified costs, i.e. you pay an increased price for the purchase of spare parts and new components if they are replaced. In case of the low capacity increasing loads on the system cause its component load increase, which leads to the breakdown. Prevention of the occurrence of failures in the system, will increase the system's trouble-free and, therefore, its reliability. Therefore, the system reliability can be controlled

    Data on morphology, large-scale chromatin configuration and the occurrence of proteins and rRNA in nucleolus-like bodies of fully-grown mouse oocytes in different fixatives

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    Here we provide data on accessibility of nucleolus-like bodies (NLBs) of fully-grown (GV) mouse oocytes to fluorescence in situ hybridization (FISH) probes and anti-nucleolar antibodies as well as on oocyte general morphology and large scale chromatin configuration, which relate to the research article “High-resolution microscopy of active ribosomal genes and key members of the rRNA processing machinery inside nucleolus-like bodies of fully-grown mouse oocytes” (Shishova et al., 2015 [1]). Experimental factors include: a cross-linking reagent formaldehyde and two denaturing fixatives, such as 70% ethanol and a mixture of absolute methanol and glacial acetic acid (3:1, v/v)
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