3,362 research outputs found

    Andrew Cox Marshall: Centenarian, Slave, Porter

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    Andrew Cox Marshall, a mulatto slave, was born probably in 1756 in South Carolina and came to Savannah in 1766. He was a slave for approximately fifty years and was owned by at least five different men. A successful dray business enabled Marshall to purchase his freedom from a Mr. Richard Richardson sometime after 1812. Marshall\u27s first wife, also a slave was sold away from him and he never saw her again. Rachel, his second wife died in 1829 and a year or so later he married Sarah a woman thirty-nine years younger than himself. There were twenty children born to Marshall, however only one, George, would survive his father. In 1812 he became pastor of the First African Baptist Church where he served until his death on December 7, 1856. Marshall is most noted for the leadership of his flock and through a schism in 1832 over a \u27\u27Campbell and Dunning Doctrine\u27\u27 which caused 155 members to split £rom his church. Andrew Cox Marshall was a man who was well respected by both white and black and he carried much influence in the city of Savannah during the latter years of his life.https://digitalcommons.georgiasouthern.edu/sav-bios-lane/1191/thumbnail.jp

    Phenotypic and Functional Heterogeneity of Macrophages and Dendritic Cell Subsets in the Healthy and Atherosclerosis-Prone Aorta

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    Atherosclerosis continues to be the leading cause of cardiovascular disease. Development of atherosclerosis depends on chronic inflammation in the aorta and multiple immune cells are involved in this process. Importantly, resident macrophages and dendritic cells (DCs) are present within the healthy aorta, but the functions of these cells remain poorly characterized. Local inflammation within the aortic wall promotes the recruitment of monocytes and DC precursors to the aorta and micro-environmental factors direct the differentiation of these emigrated cells into multiple subsets of macrophages and DCs. Recent data suggest that several populations of macrophages and DCs can co-exist within the aorta. Although the functions of M1, M2, Mox, and M4 macrophages are well characterized in vitro, there is a limited set of data on the role of these populations in atherogenesis in vivo. Recent studies on the origin and the potential role of aortic DCs provide novel insights into the biology of aortic DC subsets and prospective mechanisms of the immune response in atherosclerosis. This review integrates the results of experiments analyzing heterogeneity of DCs and macrophage subsets in healthy and diseased vessels and briefly discusses the known and potential functions of these cells in atherogenesis

    Direct Supply Control: What Effects on Iowa Farms?

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    Researchers study effects of reducing concentrate output 20 percent through direct supply control (marketing quotes) on farm labor, land, capital and net farm income under 19 different farm siutations in Iowa

    (2E)-3-(4-Chloro­phen­yl)-1-(4-hy­droxy­phen­yl)prop-2-en-1-one

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    In the title compound, C15H11ClO2, the dihedral angle between the mean planes of the chloro­benzene and hy­droxy­benzene rings is 6.5 (6)°. The mean plane of the prop-2-en-1-one group makes an angle of 18.0 (1)° with the hy­droxy­phenyl ring and 11.5 (1)° with the chloro­phenyl ring. The crystal packing is stabilized by inter­molecular O—H⋯O hydrogen bonds, weak C—H⋯O, C—H⋯π and π–π stacking inter­actions [centroid–centroid distances = 3.7771 (7) and 3.6917 (7) Å]

    Full Scale Proton Beam Impact Testing of new CERN Collimators and Validation of a Numerical Approach for Future Operation

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    New collimators are being produced at CERN in the framework of a large particle accelerator upgrade project to protect beam lines against stray particles. Their movable jaws hold low density absorbers with tight geometric requirements, while being able to withstand direct proton beam impacts. Such events induce considerable thermo-mechanical loads, leading to complex structural responses, which make the numerical analysis challenging. Hence, an experiment has been developed to validate the jaw design under representative conditions and to acquire online results to enhance the numerical models. Two jaws have been impacted by high-intensity proton beams in a dedicated facility at CERN and have recreated the worst possible scenario in future operation. The analysis of online results coupled to post-irradiation examinations have demonstrated that the jaw response remains in the elastic domain. However, they have also highlighted how sensitive the jaw geometry is to its mounting support inside the collimator. Proton beam impacts, as well as handling activities, may alter the jaw flatness tolerance value by ±\pm 70 μ{\mu}m, whereas the flatness tolerance requirement is 200 μ{\mu}m. In spite of having validated the jaw design for this application, the study points out numerical limitations caused by the difficulties in describing complex geometries and boundary conditions with such unprecedented requirements.Comment: 22 pages, 17 figures, Prepared for submission to JINS

    Gravity from self-interaction redux

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    I correct some recent misunderstandings about, and amplify some details of, an old explicit non-geometrical derivation of GR.Comment: Final, amplified, published version; GRG (2009

    Propagation and interaction of ultrashort electromagnetic pulses in nonlinear media with a quadratic-cubic nonlinearity

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    Propagation of extremely short unipolar pulses of electromagnetic field ("videopulses") is considered in the framework of a model in which the material medium is represented by anharmonic oscillators (approximating bound electrons) with quadratic and cubic nonlinearities. Two families of exact analytical solutions (with positive or negative polarity) are found for the moving solitary pulses. Direct simulations demonstrate that the pulses are very robust against perturbations. Two unipolar pulses collide nearly elastically, while collisions between pulses with opposite polarities and a small relative velocity are inelastic, leading to emission of radiation and generation of a small-amplitude additional pulse.Comment: 12 pages, 10 figure

    Antimicrobial treatment improves mycobacterial survival in nonpermissive growth conditions

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    Antimicrobials targeting cell wall biosynthesis are generally considered inactive against nonreplicating bacteria. Paradoxically, we found that under nonpermissive growth conditions, exposure of Mycobacterium bovis BCG bacilli to such antimicrobials enhanced their survival. We identified a transcriptional regulator, RaaS (for regulator of antimicrobial-assisted survival), encoded by bcg1279 (rv1219c) as being responsible for the observed phenomenon. Induction of this transcriptional regulator resulted in reduced expression of specific ATP-dependent efflux pumps and promoted long-term survival of mycobacteria, while its deletion accelerated bacterial death under nonpermissive growth conditions in vitro and during macrophage or mouse infection. These findings have implications for the design of antimicrobial drug combination therapies for persistent infectious diseases, such as tuberculosis
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