699 research outputs found

    Angielskie i polskie miasta we wspomnieniach siedemnastowiecznych peregrynatnĆ³w z obu krajĆ³w

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    This article is devoted to particular aspects of 17th-century travel writing. It analyzes selected works of english travellers visiting Poland and, conversely, Poles describing their tours of Britain. By combining specific extracts of these memoirs, focusing mainly on the descriptions of towns and cities visited by the correspondents, the author of the article discusses the differences and similarities in selected points ofĀ  description (e.g. the fortifications ofĀ  a particular town), indicating the influences ofĀ  the diaristsā€™ cultural backgrounds, the functioning stereotypes of the period, the contemporary political and religious climate, the purpose and length of their visits and other factors that affected the individual writerā€™s perspective

    Epstein-Barr virus nuclear antigen EBNA-LP is essential for transforming naĆÆve B cells, and facilitates recruitment of transcription factors to the viral genome.

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    The Epstein-Barr virus (EBV) nuclear antigen leader protein (EBNA-LP) is the first viral latency-associated protein produced after EBV infection of resting B cells. Its role in B cell transformation is poorly defined, but it has been reported to enhance gene activation by the EBV protein EBNA2 in vitro. We generated EBNA-LP knockout (LPKO) EBVs containing a STOP codon within each repeat unit of internal repeat 1 (IR1). EBNA-LP-mutant EBVs established lymphoblastoid cell lines (LCLs) from adult B cells at reduced efficiency, but not from umbilical cord B cells, which died approximately two weeks after infection. Adult B cells only established EBNA-LP-null LCLs with a memory (CD27+) phenotype. Quantitative PCR analysis of virus gene expression after infection identified both an altered ratio of the EBNA genes, and a dramatic reduction in transcript levels of both EBNA2-regulated virus genes (LMP1 and LMP2) and the EBNA2-independent EBER genes in the first 2 weeks. By 30 days post infection, LPKO transcription was the same as wild-type EBV. In contrast, EBNA2-regulated cellular genes were induced efficiently by LPKO viruses. Chromatin immunoprecipitation revealed that EBNA2 and the host transcription factors EBF1 and RBPJ were delayed in their recruitment to all viral latency promoters tested, whereas these same factors were recruited efficiently to several host genes, which exhibited increased EBNA2 recruitment. We conclude that EBNA-LP does not simply co-operate with EBNA2 in activating gene transcription, but rather facilitates the recruitment of several transcription factors to the viral genome, to enable transcription of virus latency genes. Additionally, our findings suggest that EBNA-LP is essential for the survival of EBV-infected naĆÆve B cells

    Origin of the complex radio structure in BAL QSO 1045+352

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    We present new more sensitive high-resolution radio observations of a compact broad absorption line (BAL) quasar, 1045+352, made with the EVN+MERLIN at 5 GHz. They allowed us to trace the connection between the arcsecond structure and the radio core of the quasar. The radio morphology of 1045+352 is dominated by a knotty jet showing several bends. We discuss possible scenarios that could explain such a complex morphology: galaxy merger, accretion disk instability, precession of the jet and jet-cloud interactions. It is possible that we are witnessing an ongoing jet precession in this source due to internal instabilities within the jet flow, however, a dense environment detected in the submillimeter band and an outflowing material suggested by the X-ray absorption could strongly interact with the jet. It is difficult to establish the orientation between the jet axis and the observer in 1045+352 because of the complex structure. Nevertheless taking into account the most recent inner radio structure we conclude that the radio jet is oriented close to the line of sight which can mean that the opening angle of the accretion disk wind can be large in this source. We also suggest that there is no direct correlation between the jet-observer orientation and the possibility of observing BALs.Comment: 8 pages, 3 figures, accepted for publication in Ap

    X-rays from a radio-loud compact BAL Quasar 1045+352 and the nature of outflows in radio-loud BAL Quasars

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    We present new results on X-ray properties of radio loud broad absorption line (BAL) quasars and focus on broad-band spectral properties of a high ionization BAL (HiBAL) compact steep spectrum (CSS) radio-loud quasar 1045+352. This HiBAL quasar has a very complex radio morphology indicating either strong interactions between a radio jet and the surrounding interstellar medium or a possible re-start of the jet activity. We detected 1045+352 quasar in a short 5 ksec Chandra ACIS-S observation. We applied theoretical models to explain spectral energy distribution (SED) of 1045+352 and argue that non-thermal, inverse-Compton emission from the innermost parts of the radio jet can account for a large fraction of the observed X-ray emission. In our analysis we also consider a scenario in which the observed X-ray emission from radio-loud BAL quasars can be a sum of inverse-Compton jet X-ray emission and optically thin corona X-ray emission. We compiled a sample of radio-loud BAL quasars that were observed in X-rays to date and report no correlation between their X-ray and radio luminosity. However, the radio-loud BAL quasars show a large range of X-ray luminosities and absorption columns. This is consistent with the results obtained earlier for radio-quiet BAL quasars and may indicate an orientation effect in BAL quasars or more complex dependence between X-ray emission, radio emission and an orientation based on the radio morphology.Comment: 10 pages, 3 figures, accepted for publication in ApJ, corrected typos and reference

    The structure of M.EcoKI Type I DNA methyltransferase with a DNA mimic antirestriction protein

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    Type-I DNA restrictionā€“modification (R/M) systems are important agents in limiting the transmission of mobile genetic elements responsible for spreading bacterial resistance to antibiotics. EcoKI, a Type I R/M enzyme from Escherichia coli, acts by methylation- and sequence-specific recognition, leading to either methylation of DNA or translocation and cutting at a random site, often hundreds of base pairs away. Consisting of one specificity subunit, two modification subunits, and two DNA translocase/endonuclease subunits, EcoKI is inhibited by the T7 phage antirestriction protein ocr, a DNA mimic. We present a 3D density map generated by negative-stain electron microscopy and single particle analysis of the central core of the restriction complex, the M.EcoKI M2S1 methyltransferase, bound to ocr. We also present complete atomic models of M.EcoKI in complex with ocr and its cognate DNA giving a clear picture of the overall clamp-like operation of the enzyme. The model is consistent with a large body of experimental data on EcoKI published over 40 years

    Biological Denitrification of High Nitrate Processing Wastewaters from Explosives Production Plant

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    Wastewater samples originating from an explosives production plant (3,000Ā mgĀ N lāˆ’1 nitrate, 4.8Ā mgĀ lāˆ’1 nitroglycerin, 1.9Ā mgĀ lāˆ’1 nitroglycol and 1,200Ā mgĀ lāˆ’1 chemical oxygen demand) were subjected to biological purification. An attempt to completely remove nitrate and to decrease the chemical oxygen demand was carried out under anaerobic conditions. A soil isolated microbial consortium capable of biodegrading various organic compounds and reduce nitrate to atmospheric nitrogen under anaerobic conditions was used. Complete removal of nitrates with simultaneous elimination of nitroglycerin and ethylene glycol dinitrate (nitroglycol) was achieved as a result of the conducted research. Specific nitrate reduction rate was estimated at 12.3Ā mgĀ N gāˆ’1 VSS hāˆ’1. Toxicity of wastewater samples during the denitrification process was studied by measuring the activity of dehydrogenases in the activated sludge. Mutagenicity was determined by employing the Ames test. The maximum mutagenic activity did not exceed 0.5. The obtained results suggest that the studied wastewater samples did not exhibit mutagenic properties

    FBXO7 sensitivity of phenotypic traits elucidated by a hypomorphic allele.

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    FBXO7 encodes an F box containing protein that interacts with multiple partners to facilitate numerous cellular processes and has a canonical role as part of an SCF E3 ubiquitin ligase complex. Mutation of FBXO7 is responsible for an early onset Parkinsonian pyramidal syndrome and genome-wide association studies have linked variants in FBXO7 to erythroid traits. A putative orthologue in Drosophila, nutcracker, has been shown to regulate the proteasome, and deficiency of nutcracker results in male infertility. Therefore, we reasoned that modulating Fbxo7 levels in a murine model could provide insights into the role of this protein in mammals. We used a targeted gene trap model which retained 4-16% residual gene expression and assessed the sensitivity of phenotypic traits to gene dosage. Fbxo7 hypomorphs showed regenerative anaemia associated with a shorter erythrocyte half-life, and male mice were infertile. Alterations to T cell phenotypes were also observed, which intriguingly were both T cell intrinsic and extrinsic. Hypomorphic mice were also sensitive to infection with Salmonella, succumbing to a normally sublethal challenge. Despite these phenotypes, Fbxo7 hypomorphs were produced at a normal Mendelian ratio with a normal lifespan and no evidence of neurological symptoms. These data suggest that erythrocyte survival, T cell development and spermatogenesis are particularly sensitive to Fbxo7 gene dosage

    Deliberation on Childhood Vaccination in Canada: Public Input on Ethical Trade-Offs in Vaccination Policy

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    Background: Policy decisions about childhood vaccination require consideration of multiple, sometimes conflicting, public health and ethical imperatives. Examples of these decisions are whether vaccination should be mandatory and, if so, whether to allow for non-medical exemptions. In this article we argue that these policy decisions go beyond typical public health mandates and therefore require democratic input. Methods: We report on the design, implementation, and results of a deliberative public forum convened over four days in Ontario, Canada, on the topic of childhood vaccination. Results: 25 participants completed all four days of deliberation and collectively developed 20 policy recommendations on issues relating to mandatory vaccinations and exemptions, communication about vaccines and vaccination, and AEFI (adverse events following immunization) compensation and reporting. Notable recommendations include unanimous support for mandatory childhood vaccination in Ontario, the need for broad educational communication about vaccination, and the development of a no-fault compensation scheme for AEFIs. There was persistent disagreement among deliberants about the form of exemptions from vaccination (conscience, religious beliefs) that should be permissible, as well as appropriate consequences if parents do not vaccinate their children. Conclusions: We conclude that conducting deliberative democratic processes on topics that are polarizing and controversial is viable and should be further developed and implemented to support democratically legitimate and trustworthy policy about childhood vaccination
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