85 research outputs found

    Lysosomal Membrane Permeabilization Induces Cell Death in a Mitochondrion-dependent Fashion

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    A number of diseases are due to lysosomal destabilization, which results in damaging cell loss. To investigate the mechanisms of lysosomal cell death, we characterized the cytotoxic action of two widely used quinolone antibiotics: ciprofloxacin (CPX) or norfloxacin (NFX). CPX or NFX plus UV light (NFX*) induce lysosomal membrane permeabilization (LMP), as detected by the release of cathepsins from lysosomes. Inhibition of the lysosomal accumulation of CPX or NFX suppresses their capacity to induce LMP and to kill cells. CPX- or NFX-triggered LMP results in caspase-independent cell death, with hallmarks of apoptosis such as chromatin condensation and phosphatidylserine exposure on the plasma membrane. LMP triggers mitochondrial membrane permeabilization (MMP), as detected by the release of cytochrome c. Both CPX and NFX* cause Bax and Bak to adopt their apoptotic conformation and to insert into mitochondrial membranes. Bax−/− Bak−/− double knockout cells fail to undergo MMP and cell death in response to CPX- or NFX-induced LMP. The single knockout of Bax or Bak (but not Bid) or the transfection-enforced expression of mitochondrion-targeted (but not endoplasmic reticulum–targeted) Bcl-2 conferred protection against CPX (but not NFX*)-induced MMP and death. Altogether, our data indicate that mitochondria are indispensable for cell death initiated by lysosomal destabilization

    The visual and material dimensions of legitimacy:Accounting and the search for Socie-ties

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    We are grateful to the Fondation Audencia for the financial support provided for our archival research.The aim of this article is to contribute to the literature on legitimacy by investigating its material and visual dimensions. By drawing on studies on rhetoric as a means of composing visions of social order and on an historical analysis of accounts in three paradigmatic eras (Roman times, Renaissance and Modernity), it shows how symmetry in accounts constituted an aesthetic code which tied members of a community together in ‘socie-ties’. We investigate the rhetorical process of ratiocinatio and explore how the visual and material dimensions of accounts provided social actors with an opportunity to explore their positions and ties within a community. This process augmented social actors’ understanding of their current relations by reducing them to a series of entries into an account, thus allowing them to reflect on what it meant to be a legitimate member of a society.PostprintPeer reviewe

    Datos en tiempos de pandemia: la urgencia de un nuevo pacto. Reflexiones desde América Latina y el Caribe

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    Los avances de las Tecnologías de la Información y la Comunicación (TIC) permiten acceder en tiempo real a una cantidad ingente de datos, a través de los cuales es posible conocer el comportamiento de hechos sociales. En este escenario, la actual pandemia por SARS-CoV-2 ha permitido, bajo cuestionables criterios de inmediatez y urgencia, circular información que genera realidad e impacta en la toma de decisiones; y, además, ha favorecido la apropiación del dato, exponiendo a las personas a violaciones de sus derechos fundamentales. Ambos asuntos son sensibles para América Latina y el Caribe, región que hoy se presenta no sólo como el epicentro de la pandemia sino también de las desigualdades. La contribución que desde la reflexión y deliberación bioética puede realizarse en esta materia, adquiere especial relevancia con vistas a generar un nuevo pacto para el tratamiento de los datos.

    Why do banks promise to pay par on demand?

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    We survey the theories of why banks promise to pay par on demand and examine evidence about the conditions under which banks have promised to pay the par value of deposits and banknotes on demand when holding only fractional reserves. The theoretical literature can be broadly divided into four strands: liquidity provision, asymmetric information, legal restrictions, and a medium of exchange. We assume that it is not zero cost to make a promise to redeem a liability at par value on demand. If so, then the conditions in the theories that result in par redemption are possible explanations of why banks promise to pay par on demand. If the explanation based on customers’ demand for liquidity is correct, payment of deposits at par will be promised when banks hold assets that are illiquid in the short run. If the asymmetric-information explanation based on the difficulty of valuing assets is correct, the marketability of banks’ assets determines whether banks promise to pay par. If the legal restrictions explanation of par redemption is correct, banks will not promise to pay par if they are not required to do so. If the transaction explanation is correct, banks will promise to pay par value only if the deposits are used in transactions. After the survey of the theoretical literature, we examine the history of banking in several countries in different eras: fourth-century Athens, medieval Italy, Japan, and free banking and money market mutual funds in the United States. We find that all of the theories can explain some of the observed banking arrangements, and none explain all of them

    The Strength–Grain Size Relationship in Ultrafine-Grained Metals

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    Elaboration and electro-optic study of a new type of open porosity PDLC

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    A new polymer dispersed liquid crystal (PDLC) system characterized by easy processing and an open porosity has been elaborated. This PDLC is based on a pre-formed, porous, thin polymer film of a commercially available PVDF-HFP copolymer wetted by the eutectic mixture of cyano bi- and ter-phenyls known as E7 (Merck Ltd, UK). This new process is of interest because of its simplicity, and the fact that there is no risk of intermixing between the liquid crystal and the polymer matrix as occurs in a conventional PDLC. An electric field applied across the thin film results in a change in its transmission, due to the reorientation of the liquid crystal director, as already known for closed porosity PDLCs. The electro-optic properties of this PDLC have been studied and semi-quantitatively interpreted on the basis of the response theory of conventional closed porosity PDLCs

    CIL IV, 9591 : un transport de bl\ue9 entre Ostie et Pomp\ue9i \u2013 II

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    CIL IV, 9591: A grain transport between Ostia and Pompeii. In a previous article (2016), we established the text of a seven-line inscription written on the wall of a small vase found at Pompeii, the container of a sample of grain. We outline here our comments. The grain originated from Africa and was bound for Ostia. To explain why it was redirected to Pompeii, we rely on the recently published inscription of the tomb of Alleius Nigidius Maius, which exemplifies the possibility of periods of shortage and high grain prices in Pompeii, in this case around the middle of the first century. We surmise that the same thing occurred after the 62 earthquake: the magister nauis arriving at Ostia was informed of a better price at Pompeii and decided to change the ship\u2019s destination. The inscription affords the only realistic price of maritime shipping in the Roman period. The article ends with a short commentary on the shipping costs and a study of the paleography of the inscription
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