1,037 research outputs found

    America\u27s Learning about Foreign Places through the eyes of Missionaries: Writings in the Friends\u27 Missionary Advocate, 1885-1933

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    Missionaries were among the travelers who supplied American adults and children with information about foreign places. Because they enjoyed a high status and respect with their home congregations and because they lived among peoples in foreign, often exotic, lands, missionaries and their writings enjoyed a wide and attentive audience. Materials in The Friends\u27 Missionary Advocate between 1885 and 1933 report that information on foreign regions reached American audiences through presentations at monthly and quarterly meetings and at yearly conferences. Articles, letters, reports, maps, and pictures were also a medium for influencing Americans\u27 impressions of the world

    Immunological reactivity of a human immunodeficiency virus type I derived peptide representing a consensus sequence of the GP120 major neutralizing region V3

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    To reduce the opportunities for human immunodeficiency virus type 1 (HIV-1) to evade vaccine induced immunity, the development of subunit vaccines must focus on the characterization of immunogenic epitopes, which are major targets for the immune system. The most dominant site for elicitation of neutralising immune response is located on the external envelope glycoprotein gp120 within the third variable domain (V3). To overcome virus type specificity of antibodies directed to the V3-domain we designed a 36 amino acids long gp120/V3-consensus peptide (V3-C36) based on published biological data and sequence comparisons of various HIV-1 virus isolates. This peptide contains a conserved core sequence which is suggested to form a surface-exposed beta-turn. This peptide also includes T-cell epitopes defined in mice and humans, an ADCC-epitope and two highly conserved cysteine residues which were oxidized to form a cystine derivate, thus allowing correct peptide folding. In ELISA-tests, this peptide reacts with at least 90% of randomly selected sera of European and African patients infected with HIV-1 and is recognized by three different HIV-1/V3 "type-specific" antisera (MN, RF, IIIB-strain). Using this peptide as immunogen in rabbits, antisera could be raised with highly cross-reactive and HIV-1/IIIB strain neutralizing properties. Moreover, HTLV/HIV-1/IIIB specific cytotoxic T-lymphocytes (CTLs) of BALB/c mice infected with a gp120 recombinant vaccinia virus recognized the central 16- and 12-mer peptides of the V3-C36 consensus peptide in cytolytic assays, indicating perfect compatibility of the consensus peptide with the IIIB-primed CTLs. The DNA-sequence encoding the V3-consensus loop region might be an important component in newly designed recombinant subunit vaccines. In addition, due to its broad serological reactivity, the V3-consensus peptide might play an important role in special diagnostic purposes

    Studies on processing, particle formation, and immunogenicity of the HIV-1 gag gene product: a possible component of a HIV vaccine

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    Antigens in a particulate conformation were shown to be highly immunogenic in mammals. For this reason, the particle forming capacity of derivatives of the HIV-1 group specific core antigen p55 gag was assayed and compared dependent on various expression systems: recombinant bacteria, vaccinia- and baculoviruses were established encoding the entire core protein p55 either in its authentic sequence or lacking the myristylation consensus signal. Moreover, p55 gag was expressed in combination with the protease (p55-PR) or with the entire polymerase (p55-pol), respectively. Budding of 100-160 nm p55 core particles, resembling immature HIV-virions, was observed in the eucaryotic expression systems only. In comparison to the vaccinia virus driven expression of p55 in mammalian cells, considerably higher yields of particulate core antigen were obtained by infection of Spodoptera frugiperda (Sf9) insect cells with the recombinant Autographa californica nuclear polyhedrosis (AcMNPV) baculovirus. Mutation of the NH2-terminal myristylation signal sequence prevented budding of the immature core particles. Expression of the HIV p55-PR gene construct by recombinant baculovirus resulted in complete processing of the p55 gag precursor molecule in this system. The introduction of an artificial frameshift near the natural frameshift site resulted in constitutive expression of the viral protease and complete processing of p55, both in Escherichia coli and in vaccinia virus infected cells. Interestingly, significant processing of p55 resembling that of HIV infected H9 cells could also be achieved in the vaccinia system by fusing the entire pol gene to the gag gene. Moreover, processing was not found to be dependent on amino-terminal myristylation of the gag procursor molecule, which is in contrast to observations with type C and type D retrovirus. However, complete processing of p55 into p24, p17, p9 and p6 abolished particle formation. Purified immature HIV-virus like particles were highly immunogenic in rabbits, leading to a strong humoral immune response after immunization. Empty immature p55 gag particles represent a noninfectious and attractive candidate for a basic vaccine component

    Carbon cycling and translocation processes in Baltic Sea coastal dune topsoils

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    Chronosequenzen bieten ideale Voraussetzungen zur Analyse des Einflusses pedo­genetischer Prozesse auf die Kohlenstoff- und Stickstoffdynamik im Boden. Die sich ändernden Verfügbarkeiten von Kohlenstoff (C) und Stickstoff (N) während der Pedogenese beeinflussen den Umsatz von organischer Bodensubstanz (OBS). Vergangene Arbeiten konnten zeigen, dass die Verteilung stabiler C Isotope im Oberboden zur Abschätzung des Umsatzes von OBS herangezogen werden kann. Entlang einer Dünenchronosequenz in Haast (Neuseeland) stieg der Umsatz von OBS zu Beginn der Pedogenese und erreichte einen Tiefpunkt nach dem Zerfall der Bäume aus erster Generation. Zudem zeigten C-13 Tiefenprofile Parallelen zur vertikalen Verteilung stabiler N Isotope im Oberboden. Ziele dieser Studie sind die Untersuchung von C-13 und 15-N Tiefenprofilen entlang einer Dünenchronosequenz der Ostsee. Hierzu werden entlang einer 60 bis 5500 Jahre alten Dünensequenz bei Swinemünde (Polen) Bodenproben entnommen und anhand ihrer C und N Isotopenverteilungen analysiert. Es wird ein Anstieg des Umsatzes durch ansteigende C Gehalte in frühen Phasen der Pedogenese erwartet. Atmosphärische N Deposition kann einen erheblichen Effekt auf die Vegetations- und mikrobielle Zusammensetzung sowie Umsatzprozesse während der Boden- und Ökosystementwicklung haben. Große Unterschiede der N Depositionen zwischen Dünengebieten der südlichen Ostsee und Neuseeland könnten daher 13-C sowie 15-N Tiefenprofile beeinflussen. Die gewonnen Daten liefern einen wichtigen Beitrag zum Verständnis der C Sequestrierung und der Stickstoffdynamik während der Pedogenese

    Photocatalytic degradation of diclofenac in wastewater using ironceramic composites

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    The photocatalytic degradation of diclofenac in model aqueous solution is investigated. The surface of composites were correlated with photocatalytic activity. Adsorption activity of the composites is related to the presence of surface active sites. The degradation under UV irradiation and photo-Fenton process using ironceramic composites is more effective than direct photolysis

    Carbon allocation to root exudates is maintained in mature temperate tree species under drought

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    - Carbon (C) exuded via roots is proposed to increase under drought and facilitate important ecosystem functions. However, it is unknown how exudate quantities relate to the total C budget of a drought-stressed tree, that is, how much of net-C assimilation is allocated to exudation at the tree level. - We calculated the proportion of daily C assimilation allocated to root exudation during early summer by collecting root exudates from mature Fagus sylvatica and Picea abies exposed to experimental drought, and combining above- and belowground C fluxes with leaf, stem and fine-root surface area. - Exudation from individual roots increased exponentially with decreasing soil moisture, with the highest increase at the wilting point. Despite c. 50% reduced C assimilation under drought, exudation from fine-root systems was maintained and trees exuded 1.0% (F. sylvatica) to 2.5% (P. abies) of net C into the rhizosphere, increasing the proportion of C allocation to exudates two- to three-fold. Water-limited P. abies released two-thirds of its exudate C into the surface soil, whereas in droughted F. sylvatica it was only one-third. - Across the entire root system, droughted trees maintained exudation similar to controls, suggesting drought-imposed belowground C investment, which could be beneficial for ecosystem resilience
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