115 research outputs found

    Deep Photometry of GRB 041006 Afterglow: Hypernova Bump at Redshift z=0.716

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    We present deep optical photometry of the afterglow of gamma-ray burst (GRB) 041006 and its associated hypernova obtained over 65 days after detection (55 R-band epochs on 10 different nights). Our early data (t<4 days) joined with published GCN data indicates a steepening decay, approaching F_nu ~t^{-0.6} at early times (<<1 day) and F_nu ~t^{-1.3} at late times. The break at t_b=0.16+-0.04 days is the earliest reported jet break among all GRB afterglows. During our first night, we obtained 39 exposures spanning 2.15 hours from 0.62 to 0.71 days after the burst that reveal a smooth afterglow, with an rms deviation of 0.024 mag from the local power-law fit, consistent with photometric errors. After t~4 days, the decay slows considerably, and the light curve remains approximately flat at R~24 mag for a month before decaying by another magnitude to reach R~25 mag two months after the burst. This ``bump'' is well-fitted by a k-corrected light curve of SN1998bw, but only if stretched by a factor of 1.38 in time. In comparison with the other GRB-related SNe bumps, GRB 041006 stakes out new parameter space for GRB/SNe, with a very bright and significantly stretched late-time SN light curve. Within a small sample of fairly well observed GRB/SN bumps, we see a hint of a possible correlation between their peak luminosity and their ``stretch factor'', broadly similar to the well-studied Phillips relation for the type Ia supernovae.Comment: ApJ Letters, accepted. Additional material available at ftp://cfa-ftp.harvard.edu/pub/kstanek/GRB041006

    Utilization of Immunoblotting in Studies of Epitope Targeting in Monoclonal Antibodies to Melioidosis Agent Antigen 200 kDa

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    Objective of the research was to use immunoblotting for studies of epitope targeting in monoclonal antibodies to 200 kDa Burkholderia pseudomallei antigen, which are synthesized by hybridomas-producers from the two collections in the laboratory of immunodiagnostics and biotechnology at the premises of Volgograd Research Anti-Plague Institute. Employed were 8 typical strains of melioidosis agent with the complete antigenic structure. Antigen preparations were separated by means of denaturating vertical electrophoresis in 12 % polyacrylamide gel with 0.1 % sodium dodecylsulfate. During the process of cell-replication, 12 hybridomas-producers were given preparative amounts of monoclonal antibodies to 200 kDa Burkholderia pseudomallei glycoprotein. Following that, immunoperoxidase conjugates were manufactured. Epitope targeting of monoclonal antibodies was evaluated using immunoblotting. With the help of vertical electrophoresis identified was the presence of several mandatory major components contained in the antigen complexes of the salt-water and formamid B. pseudomallei extracts . Differential staining substantiated glycoprotein origin of certain antigen components. Immunoblotting with the stated above antigen preparations revealed epitope targeting of a number of monoclonal antibodies to 200 kDa antigen of melioidosis agent; demonstrated were the differences in their specific interaction with biopolymers which form part of the antigen specter. Those differences were characteristic of hybridomas-producers belonging to different collections, as well as of particular strains of B. pseudomallei

    “Report on the Activities of the Imperial Moscow Technical School for the Academic Year 1878–1879” as a Historical Source on the Development of Scientific and Technical Knowledge in the Russian Empire at the End of the 19th Century

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    Статья рассматривает опубликованный «Отчет о деятельности Императорского Московского технического училища за 1878–1879 академический год» как исторический источник о развитии научно-технического знания в России конца XIX века. Вошедший в него Краткий отчет Императорского Московского технического училища за 1878–1879 учебный год, представленный В. К. Делла-Восом, позволяет оценить огромный объем работы Преподавательского совета училища по улучшению инженерного образования в России. Это и разработка уникальной системы обучения, и введение репетиторства для укрепления теоретических знаний учащихся, и получение ими профессионального опыта в мастерских и лаборатории училища. Отчет дает представление о специфике принятой в училище системы обучения и руководства учебной деятельностью, которую можно охарактеризовать как передовую для своего времени. Отчет Я. Я. Никитинского о деятельности Политехнического общества при Императорском Московском техническом училище показывает большое ее значение для формирования связи научных и технических сторон и достижений, создания единого научно-технического сообщества в России, продвижения науки в технической сфере и широкого просвещения специалистовThe article examines the published “Report on the activities of the Imperial Moscow Technical School for the 1878–79 academic year” as a historical source concerning the development of scientific and technical knowledge in Russia at the end of the 19th century. The Brief Report of the Imperial Moscow Technical School for the 1878–1879 academic year, presented by V. K. Della-Vos, included in it, allows us to evaluate the enormous amount of work of the school’s teaching council to improve engineering education in Russia. This covers the development of a unique training system, and the introduction of tutoring to strengthen theoretical knowledge of students and allow them to gain professional experience in the school’s workshops and laboratories. The report gives an idea of the specifics of the teaching and management of educational activities system adopted at the school, which can be described as advanced one for its time. The report by Ya. Ya. Nikitinsky dealing with the activities of the Polytechnic Society at the Imperial Moscow Technical School shows its great importance for the formation of a connection between scientific and technical aspects and achievements, the creation of a unified scientific and technical community in Russia, the promotion of science in the technical field and the broad education of specialist

    Study of air conditioning systems for storage and display of art works

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    The article describes technical characteristics of modern air conditioning systems that are of use to ensure the ambient conditions required for storage and display of art works in art museums. The author performs comparison analysis of centralized and autonomous air conditioning systems. The article includes an inference about how important it is to combine elements of both systems according to the design tasks and features of the integrated museum and exhibition platform (Museum Quarter in Krasnoyarsk), which includes historical buildings and new modern exhibition areas

    Characterization of toxigenic Corynebacterium diphtheriae strains isolated in Russia

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    The aim of the study was to characterize toxigenic strains of Corynebacterium diphtheriae by examining 12 toxigenic strains of C. diphtheriae isolated in Russia between January, 2017 to June, 2019. The morphological, toxigenic and biochemical properties of C. diphtheriae was studied. Genotyping of C. diphtheriae strains was performed using MLST and dtxR gene sequencing with subsequent phylogenetic analysis. Results. Toxigenic strains of C. diphtheriae were isolated in the Novosibirsk, Samara and Chelyabinsk Regions, the Khanty-Mansi Autonomous Okrug — Yugra as well as the Republic of Northern Ossetia — Alania. Among these strains, 5 were isolated from diphtheria patients (moderate disease found in one case, mild course — remaining patients) and 7 strains were isolated from bacterial carriers. In two cases C. diphtheriae from diphtheria patients were identified as ST25 sequence type, gravis variant; in one case — ST8 type, gravis variant; two cases — ST67 sequence type, mitis variant. In asymptomatic carriers of tox-positive C. diphtheriae strains they belonged to ST25 sequence type, gravis variant — in two cases, ST67 type, mitis variant — in four cases. A sequencing type was not identified in one case. All sequence types were widespread globally being presented by a large number of isolates in the PubMLST and characterized by a substantial amount of derivative sequence types. At the same time, they belonged to different clonal complexes and differed markedly from each other contributing to their reliable difference as assessed by MLST. Study of gene dtxR sequence diversity showed that all allelic variants were typical for the representatives of these sequence types. New alleles of gene dtxR were not revealed in strains examined. It was shown that non-synonymous substitution C440T leading to A147V amino acid substitution was found solely in one allele distributed in ST8, ST185, ST195 and ST451 types suggesting at late mutation. In contrast, the polymorphism C640A resulting in the amino acid substitution L214I was found not only in the same allele, but also in the basal tree branches indicating that isoleucine was in the ancestral sequence of the protein

    Obtainment of Monoclonal Antibodies and Prospects of Their Application as Basis for Immunodiagnostic Aids for Crimean-Congo Hemorrhagic Fever Virus Detection

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    ) as framework for the production of tools for CCHF virus detection and identification in artificially contaminated samples and clinical specimens containing CCHF antigens was proven efficient

    Blood-based biomarkers for Alzheimer disease: mapping the road to the clinic.

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    Biomarker discovery and development for clinical research, diagnostics and therapy monitoring in clinical trials have advanced rapidly in key areas of medicine - most notably, oncology and cardiovascular diseases - allowing rapid early detection and supporting the evolution of biomarker-guided, precision-medicine-based targeted therapies. In Alzheimer disease (AD), breakthroughs in biomarker identification and validation include cerebrospinal fluid and PET markers of amyloid-β and tau proteins, which are highly accurate in detecting the presence of AD-associated pathophysiological and neuropathological changes. However, the high cost, insufficient accessibility and/or invasiveness of these assays limit their use as viable first-line tools for detecting patterns of pathophysiology. Therefore, a multistage, tiered approach is needed, prioritizing development of an initial screen to exclude from these tests the high numbers of people with cognitive deficits who do not demonstrate evidence of underlying AD pathophysiology. This Review summarizes the efforts of an international working group that aimed to survey the current landscape of blood-based AD biomarkers and outlines operational steps for an effective academic-industry co-development pathway from identification and assay development to validation for clinical use.I recieved an honorarium from Roche Diagnostics for my participation in the advisory panel meeting leading to this pape

    A common haplotype lowers PU.1 expression in myeloid cells and delays onset of Alzheimer's disease

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    A genome-wide survival analysis of 14,406 Alzheimer's disease (AD) cases and 25,849 controls identified eight previously reported AD risk loci and 14 novel loci associated with age at onset. Linkage disequilibrium score regression of 220 cell types implicated the regulation of myeloid gene expression in AD risk. The minor allele of rs1057233 (G), within the previously reported CELF1 AD risk locus, showed association with delayed AD onset and lower expression of SPI1 in monocytes and macrophages. SPI1 encodes PU.1, a transcription factor critical for myeloid cell development and function. AD heritability was enriched within the PU.1 cistrome, implicating a myeloid PU.1 target gene network in AD. Finally, experimentally altered PU.1 levels affected the expression of mouse orthologs of many AD risk genes and the phagocytic activity of mouse microglial cells. Our results suggest that lower SPI1 expression reduces AD risk by regulating myeloid gene expression and cell function
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