98 research outputs found

    The Plasmodium translocon of exported proteins (PTEX) component thioredoxin-2 is important for maintaining normal blood-stage growth

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    Plasmodium parasites remodel their vertebrate host cells by translocating hundreds of proteins across an encasing membrane into the host cell cytosol via a putative export machinery termed PTEX. Previously PTEX150, HSP101 and EXP2 have been shown to be bona fide members of PTEX. Here we validate that PTEX88 and TRX2 are also genuine members of PTEX and provide evidence that expression of PTEX components are also expressed in early gametocytes, mosquito and liver stages, consistent with observations that protein export is not restricted to asexual stages. Although amenable to genetic tagging, HSP101, PTEX150, EXP2 and PTEX88 could not be genetically deleted in Plasmodium berghei, in keeping with the obligatory role this complex is postulated to have in maintaining normal blood-stage growth. In contrast, the putative thioredoxin-like protein TRX2 could be deleted, with knockout parasites displaying reduced grow-rates, both in vivo and in vitro, and reduced capacity to cause severe disease in a cerebral malaria model. Thus, while not essential for parasite survival, TRX2 may help to optimize PTEX activity. Importantly, the generation of TRX2 knockout parasites that display altered phenotypes provides a much-needed tool to dissect PTEX function

    A high implicit affiliation motive does not always make you happy: A corresponding explicit motive and corresponding behavior are further needed

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    Satisfaction of the implicit affiliation motive is known to be positively related to emotional well-being, whereas the frustration of the implicit affiliation motive leads to impairment of well-being. In the present research we specified two conditions that are responsible for the satisfaction and frustration of the implicit motive. Referring to research on the congruence of implicit and explicit motives, we assumed that a corresponding explicit affiliation motive leads to satisfaction of the implicit motive. Corresponding affiliation behavior constitutes the second condition. Three studies confirmed the hypothesis that both conditions must be fulfilled in order to positively connect the implicit affiliation motive to emotional well-being. Participants with high implicit and explicit affiliation motives and who additionally showed a large amount of affiliation behavior reported the lowest negative affectivity and the highest life satisfaction compared to participants who lacked one of the conditions

    A giant exoplanet orbiting a very-low-mass star challenges planet formation models

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    Surveys have shown that super-Earth and Neptune-mass exoplanets are more frequent than gas giants around low-mass stars, as predicted by the core accretion theory of planet formation. We report the discovery of a giant planet around the very-low-mass star GJ 3512, as determined by optical and near-infrared radial-velocity observations. The planet has a minimum mass of 0.46 Jupiter masses, very high for such a small host star, and an eccentric 204-day orbit. Dynamical models show that the high eccentricity is most likely due to planet-planet interactions. We use simulations to demonstrate that the GJ 3512 planetary system challenges generally accepted formation theories, and that it puts constraints on the planet accretion and migration rates. Disk instabilities may be more efficient in forming planets than previously thought

    CARMENES: high-resolution spectra and precise radial velocities in the red and infrared

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    SPIE Astronomical Telescopes + Instrumentation (2018, Austin, Texas, United States

    Click chemistry on self-assembled monolayer of zeolite L crystals by microcontact printing - Applications in nanobiotechnology

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    Self assembled monolayers (SAMs) of zeolite L crystals were functionalized with fluorescent dye molecules or bioactive carbohydrate using microcontact printing (mCP). Fluorescent molecules such as lissamine rhodamine (LRA) and sugars such as \u3b1-d-mannoside (\u3b1-d-Man) functionalized with a terminal acetylene spacer were immobilized by "click" reaction on the top side of an azide functionalized zeolite L monolayer. Patterned and non-patterned SAMs of \u3b1-d-Man functionalized zeolite were used for cell adhesion and cellular patterning

    Cell adhesion behavior on enantiomerically functionalized zeolite L monolayers

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    Zeolite L nanocrystals can be enantioselectively functionalized and their enantiomorphous SAMs prepared. The adhesion behavior of different cells with these new biomaterials was studied according to the respective surface chirality. This concept was demonstrated for cell separation of primary cells and cell lines (see picture)
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