156 research outputs found

    Casas para un mundo feliz. 'Design of a house for a cheerful living' 1945

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    Design of a house for Cheerful Living de 1945, patrocinado por la revista Pencil Points, se enmarca dentro de los concursos patrocinados por revistas y empresas, que trataron de dar forma al ideal de la casa suburbana y al nuevo estilo de vida del americano medio tras la Segunda Guerra Mundial. Se presentaron más de novecientas propuestas, algunas de reconocidos arquitectos, que sirvieron de origen para el desarrollo posterior de la vivienda moderna americana, sentando las bases acerca de la prefabricación, el mobiliario integrado y el ahorro energético, cuestiones cercanas a las que se plantean en la actualidad.The development of the American modern house had much to do with the numerous competitions held in the United States during the 1940s. The residential projects funded by the state were no longer built from 1943, and then the architecture tried to look ahead bringing up the design of the new post-war home. Many publications and manufacturers proposed imaginative architectural competitions, aiming to shape the ideal suburban house and the new lifestyle of the average American after the conflict. The competition “ Design of a House for Cheerful Living” from 1945, sponsored by Pencil Points magazine and the two glass companies Pittsburgh Plate Glass Co. and Pittsburgh Corning Corp., is part of this series of post-war contests. However, the reason why this competition is especially interesting as a subject of study is its synchronism with the end of the Second World War and the beginning of the euphoria and change in the American society. More than 900 proposals, many of them from renowned architects, were submitted to the competition. They provided the basis for the further development of the house, laying the foundations of prefabrication, integrated furniture and energy efficiency, issues surprisingly close to our contemporary concerns. In this way, besides showing the housing projects, the formal evolution suffered in the domestic post-war architecture will also be examined through the projects submitted by Louis Kahn, Marcel Breuer, Ralph Rapson, Philiph Johnson and Norman Fletcher. As it will be discussed, all this contributed to a deeper social change, where architects played a key role since their perspective on domestic architecture in the different competitions turned into the image of the perfect family inhabiting in a suburban residential area

    Secretion of Clostridium difficile Toxins A and B Requires the Holin-like Protein TcdE

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    The pathogenesis of Clostridium difficile, the major cause of antibiotic-associated diarrhea, is mainly associated with the production and activities of two major toxins. In many bacteria, toxins are released into the extracellular environment via the general secretion pathways. C. difficile toxins A and B have no export signature and their secretion is not explainable by cell lysis, suggesting that they might be secreted by an unusual mechanism. The TcdE protein encoded within the C. difficile pathogenicity locus (PaLoc) has predicted structural features similar to those of bacteriophage holin proteins. During many types of phage infection, host lysis is driven by an endolysin that crosses the cytoplasmic membrane through a pore formed by holin oligomerization. We demonstrated that TcdE has a holin-like activity by functionally complementing a λ phage deprived of its holin. Similar to λ holin, TcdE expressed in Escherichia coli and C. difficile formed oligomers in the cytoplamic membrane. A C. difficile tcdE mutant strain grew at the same rate as the wild-type strain, but accumulated a dramatically reduced amount of toxin proteins in the medium. However, the complemented tcdE mutant released the toxins efficiently. There was no difference in the abundance of tcdA and tcdB transcripts or of several cytoplasmic proteins in the mutant and the wild-type strains. In addition, TcdE did not overtly affect membrane integrity of C. difficile in the presence of TcdA/TcdB. Thus, TcdE acts as a holin-like protein to facilitate the release of C. difficile toxins to the extracellular environment, but, unlike the phage holins, does not cause the non-specific release of cytosolic contents. TcdE appears to be the first example of a bacterial protein that releases toxins into the environment by a phage-like system

    Identification of a novel zinc metalloprotease through a global analysis of clostridium difficile extracellular proteins

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    Clostridium difficile is a major cause of infectious diarrhea worldwide. Although the cell surface proteins are recognized to be important in clostridial pathogenesis, biological functions of only a few are known. Also, apart from the toxins, proteins exported by C. difficile into the extracellular milieu have been poorly studied. In order to identify novel extracellular factors of C. difficile, we analyzed bacterial culture supernatants prepared from clinical isolates, 630 and R20291, using liquid chromatography-tandem mass spectrometry. The majority of the proteins identified were non-canonical extracellular proteins. These could be largely classified into proteins associated to the cell wall (including CWPs and extracellular hydrolases), transporters and flagellar proteins. Seven unknown hypothetical proteins were also identified. One of these proteins, CD630_28300, shared sequence similarity with the anthrax lethal factor, a known zinc metallopeptidase. We demonstrated that CD630_28300 (named Zmp1) binds zinc and is able to cleave fibronectin and fibrinogen in vitro in a zinc-dependent manner. Using site-directed mutagenesis, we identified residues important in zinc binding and enzymatic activity. Furthermore, we demonstrated that Zmp1 destabilizes the fibronectin network produced by human fibroblasts. Thus, by analyzing the exoproteome of C. difficile, we identified a novel extracellular metalloprotease that may be important in key steps of clostridial pathogenesis

    Too Masculine, Too Bad Effects of Communion on Leaders’ Promotion of Cooperation

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    This study challenges researchers and practitioners in the field of leadership to consider communion as a relevant variable for (male) leadership effectiveness. We suggest that communal traits influence the ability of male leaders to engender cooperation and that this effect is stronger in male-dominated contexts. We argue that this is because relevant traits and leadership behaviors that underscore a sense of community are associated with stereotypically feminine roles and identity. In a series of three studies, experimental as well as survey-based, using Spanish, Dutch, and American samples, we examined such gendered construction of male leadership and its effects on cooperation. Among others, results are discussed in terms of how stereotypically masculine constructions of male leadership may create barriers to effective leadership

    Molecular imaging of glioblastoma multiforme using anti-insulin-like growth factor-binding protein-7 single-domain antibodies

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    BACKGROUND: Insulin-like growth factor-binding protein 7 (IGFBP7) is an abundant, selective and accessible biomarker of glioblastoma multiforme (GBM) tumour vessels. In this study, an anti-IGFBP7 single-domain antibody (sdAb) was developed to target GBM vessels for molecular imaging applications. METHODS: Human GBM was modelled in mice by intracranial implantation of U87MG.EGFRvIII cells. An anti-IGFBP7 sdAb, isolated from an immune llama library by panning, was assessed in vitro for its binding affinity using surface plasmon resonance and by ex vivo immunobinding on mouse and human GBM tissue. Tumour targeting by Cy5.5-labelled anti-IGFBP7 sdAb as well as by anti-IGFBP7 sdAb conjugated to PEGylated Fe3O4 nanoparticles (NPs)-Cy5.5 were assessed in U87MG.EGFRvIII tumour-bearing mice in vivo using optical imaging and in brain sections using fluorescent microscopy. RESULTS: Surface plasmon resonance analyses revealed a medium affinity (KD\ufffd40\ufffd50 nM) binding of the anti-IGFBP7 sdAb to the purified antigen. The anti-IGFBP7 sdAb also selectively bound to both mouse and human GBM vessels, but not normal brain vessels in tissue sections. In vivo, intravenously injected anti-IGFBP7 sdAb-Cy5.5 bound to GBM vessels creating high imaging signal in the intracranial tumour. Similarly, the anti-IGFBP7 sdAb-functionalised PEGylated Fe3O4 NP-Cy5.5 demonstrated enhanced tumour signal compared with non-targeted NPs. Fluorescent microscopy confirmed the presence of anti-IGFBP7 sdAb and anti-IGFBP7 sdAb- PEGylated Fe3O4 NPs selectively in GBM vessels. CONCLUSIONS: Anti-IGFBP7 sdAbs are novel GBM vessel-targeting moieties suitable for molecular imaging.Peer reviewed: YesNRC publication: Ye

    Cloning and in silico characterization of two signal peptides from Pediococcus pentosaceus and their function for the secretion of heterologous protein in Lactococcus lactis.

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    Fifty signal peptides of Pediococcus pentosaceus were characterized by in silico analysis and, based on the physicochemical analysis, (two potential signal peptides Spk1 and Spk3 were identified). The coding sequences of SP were amplified and fused to the gene coding for green fluorescent protein (GFP) and cloned into Lactococcus lactis pNZ8048 and pMG36e vectors, respectively. Western blot analysis indicated that the GFP proteins were secreted using both heterologous SPs. ELISA showed that the secretion efficiency of GFP using Spk1 (0.64 μg/ml) was similar to using Usp45 (0.62 μg/ml) and Spk3 (0.58 μg/ml)

    Signal enhancement in protein NMR using the spin-noise tuning optimum

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    We have assessed the potential of an alternative probe tuning strategy based on the spin-noise response for application in common high-resolution multi-dimensional biomolecular NMR experiments with water signal suppression on aqueous and salty samples. The method requires the adjustment of the optimal tuning condition, which may be offset by several 100 kHz from the conventional tuning settings using the noise response of the water protons as an indicator. Although the radio frequency-pulse durations are typically longer under such conditions, signal-to-noise gains of up to 22% were achieved. At salt concentrations up to 100 mM a substantial sensitivity gain was observed
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