931 resultados para Suburban lines
Resumo:
We investigated the relationship between the fusion selectivity of the envelope glycoprotein (env) and the tropism of different human immunodeficiency virus type 1 (HIV-1) isolates for CD4+ human T-cell lines vs. primary macrophages. Recombinant vaccinia viruses were prepared encoding the envs from several well-characterized HIV-1 isolates with distinct cytotropisms. Cells expressing the recombinant envs were mixed with various CD4+ partner cell types; cell fusion was monitored by a quantitative reporter gene assay and by syncytia formation. With CD4+ continuous cell lines as partners (T-cell lines, HeLa cells expressing recombinant CD4), efficient fusion occurred with the envs from T-cell line-tropic isolates (IIIB, LAV, SF2, and RF) but not with the envs from macrophage-tropic isolates (JR-FL, SF162, ADA, and Ba-L). The opposite selectivity pattern was observed with primary macrophages as cell partners; stronger fusion occurred with the envs from the macrophage-tropic than from the T-cell line-tropic isolates. All the envs showed fusion activity with peripheral blood mononuclear cells as partners, consistent with the ability of this cell population to support replication of all the corresponding HIV-1 isolates. These fusion selectivities were maintained irrespective of the cell type used to express env, thereby excluding a role for differential host cell modification. We conclude that the intrinsic fusion selectivity of env plays a major role in the tropism of a HIV-1 isolate for infection of CD4+ T-cell lines vs. primary macrophages, presumably by determining the selectivity of virus entry and cell fusion.
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The T-cell receptor (TCR) beta chain is instrumental in the progression of thymocyte differentiation from the CD4-CD8- to the CD4+CD8+ stage. This differentiation step may involve cell surface expression of novel CD3-TCR complexes. To facilitate biochemical characterization of these complexes, we established cell lines from thymic lymphomas originating from mice carrying a mutation in the p53 gene on the one hand and a mutation in TCR-alpha, TCR-beta, or the recombination activating gene 1 (RAG-1) on the other hand. The cell lines were CD4+CD8+ and appeared to be monoclonal. A cell line derived from a RAG-1 x p53 double mutant thymic lymphoma expressed low levels of CD3-epsilon, -gamma, and -delta on the surface. TCR-alpha x p53 double mutant cell lines were found to express complexes consisting of TCR-beta chains associated with CD3-epsilon, -gamma, and -delta chains and CD3-zeta zeta dimers. These lines will be useful tools to study the molecular structure and signal transducing properties of partial CD3-TCR complexes expressed on the surface of immature thymocytes.
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Mutations in the p53 gene are implicated in the pathogenesis of half of all human tumors. We have developed a simple functional assay for p53 mutation in which human p53 expressed in Saccharomyces cerevisiae activates transcription of the ADE2 gene. Consequently, yeast colonies containing wild-type p53 are white and colonies containing mutant p53 are red. Since this assay tests the critical biological function of p53, it can distinguish inactivating mutations from functionally silent mutations. By combining this approach with gap repair techniques in which unpurified p53 reverse transcription-PCR products are cloned by homologous recombination in vivo it is possible to screen large numbers of samples and multiple clones per sample for biologically important mutations. This means that mutations can be detected in tumor specimens contaminated with large amounts of normal tissue. In addition, the assay detects temperature-sensitive mutants, which give pink colonies. We show here that this form of p53 functional assay can be used rapidly to detect germline mutations in blood samples, somatic mutations in tumors, and mutations in cell lines.
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Electromagnetic coupling phenomena between overhead power transmission lines and other nearby structures are inevitable, especially in densely populated areas. The undesired effects resulting from this proximity are manifold and range from the establishment of hazardous potentials to the outbreak of alternate current corrosion phenomena. The study of this class of problems is necessary for ensuring security in the vicinities of the interaction zone and also to preserve the integrity of the equipment and of the devices there present. However, the complete modeling of this type of application requires the three- -dimensional representation of the region of interest and needs specific numerical methods for field computation. In this work, the modeling of problems arising from the flow of electrical currents in the ground (the so-called conductive coupling) will be addressed with the finite element method. Those resulting from the time variation of the electromagnetic fields (the so-called inductive coupling) will be considered as well, and they will be treated with the generalized PEEC (Partial Element Equivalent Circuit) method. More specifically, a special boundary condition on the electric potential is proposed for truncating the computational domain in the finite element analysis of conductive coupling problems, and a complete PEEC formulation for modeling inductive coupling problems is presented. Test configurations of increasing complexities are considered for validating the foregoing approaches. These works aim to provide a contribution to the modeling of this class of problems, which tend to become common with the expansion of power grids.
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Boundaries between students and teachers were once clearly defined. Students only interacted with their teachers at school. Currently, however, boundaries are becoming increasingly unclear. As technology advances, students have more venues to interact with their teachers. In addition, teachers are asked to take on more roles in their students' lives. A significant number of teachers and students engage in inappropriate relationships and the possible damage to students is high. Unfortunately, current training programs do not adequately address how teachers can maintain appropriate boundaries with their charges. This paper outlines a proposal for a new training program to fill this gap. This program utilizes training techniques that have been shown to be useful for adult learners as it helps teachers establish and maintain boundaries as well as incorporating elements of effective prevention programs.
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After the Japanese bombed Pearl Harbor during WWII, anyone of Japanese descent living on the West Coast was placed in internment camps scattered throughout the country. Life inside the camps included many different activities to make life as normal as possible. This study will focus on two intersecting day-to-day activities in particular, the practice of religion within the camps, as well as the creation of art. Art created in the camps was influenced by multiple religious traditions. An analysis of artworks created by professional and amateur artists, interviews and an examination of existing scholarship demonstrates that internment camps created a unique environment for the creation of art. The values of internees reflected the seamless coexistence of Christianity, Buddhism and Shinto in internment camp art.
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A single and very easy to use Graphical User Interface (GUI- MATLAB) based on the topological information contained in the Gibbs energy of mixing function has been developed as a friendly tool to check the coherence of NRTL parameters obtained in a correlation data procedure. Thus, the analysis of the GM/RT surface, the GM/RT for the binaries and the GM/RT in planes containing the tie lines should be necessary to validate the obtained parameters for the different models for correlating phase equlibrium data.
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This series contains one small leaf with handwritten calculations related to the number of volumes in the Harvard College Library. The verso has the note: "No. of Vol: in Harvard College 11465 vol. making one line 15380 miles long. The document is in the hand of Loammi Baldwin Sr., and may have been created in 1789 while the Library was compiling a catalog of its holdings.
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One leaf containing a handwritten set of lines for Cassius from The Adulateur: A Tragedy, as it is now acted in Upper Servia written by Mercy Otis Warren in 1772.
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This series contains one small leaf with handwritten calculations related to the number of volumes in the Harvard College Library. The verso has the note: "No. of Vol: in Harvard College 11465 vol. making one line 15380 miles long. The document is in the hand of Loammi Baldwin Sr., and may have been created in 1789 while the Library was compiling a catalog of its holdings.
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One-page handwritten remembrance written by "B. Kent," beginning "Hark, tis a voice on high--'Come to thy rest..."
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This collection contains various manifestations of a humorous poem, most often called "Lines upon the late proceedings of the College Government," written by classmates John Quincy Adams and John Murray Forbes in 1787. Both Adams and Forbes were members of the class of 1787, and the poem recounts events surrounding the pranks and ensuing punishment of two members of the class behind them, Robert Wier and James Prescott. Wier and Prescott had been caught drinking wine and making "riotous noise," and they were publicly reprimanded by Harvard President Joseph Willard and several professors and tutors, including Eliphalet Pearson, Eleazar James, Jonathan Burr, Nathan Read, and Timothy Lindall Jennison. The poem mocks these authority figures, but it spares Samuel Williams, whom it suggests was the only professor to find their antics humorous.
Resumo:
This layer is a georeferenced raster image of the historic paper map entitled: Darstellung der isodynamischen Linien : nach den Beobachtungen der magnetischen Intensität, die in den Jahren 1790 bis 1830 gemacht worden sind, Namen der Beobachter: De Rossel, A. v. Humboldt, Sabine, Hansteen, Duperrey, Keilhau u. Boeck, Keilhau, Litke, King, Due, Erman, Kupffer. Die vorlieg. Darstellung ist von Duperry, Kapitain der französ. Marine, entworfen. It was published by [Stablstich (diretion v. Kleinecht) aus der Schweinfurter Geographischen Graviranstalt de Bibliographischen Instituts] in [1849]. Scale [ca. 1:190,000,000]. The image inside the map neatline is georeferenced to the surface of the earth and fit to a non-standard 'Mercator' projection with the central meridian at 180 degrees west. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as geomagnetic isodynamic lines, selected cities and other human settlements, shoreline features, and more. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection and the Harvard University Library as part of the Open Collections Program at Harvard University project: Organizing Our World: Sponsored Exploration and Scientific Discovery in the Modern Age. Maps selected for the project correspond to various expeditions and represent a range of regions, originators, ground condition dates, scales, and purposes.