889 research outputs found

    O Brilhantismo de Turgot ā€“ Parte I

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    Neste artigo, o autor apresenta e discute a importĆ¢ncia do pensamento de Anne Robert Jacques Turgot para a HistĆ³ria do Pensamento EconĆ“mico. Destaca seu brilhantismo intelectual, sua defesa da economia de mercado e do livre comĆ©rcio, e suas contribuiƧƵes para as teorias do valor, das trocas, dos preƧos, da produĆ§Ć£o e da distribuiĆ§Ć£o

    O Brilhantismo de Turgot ā€“ Parte II

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    Neste artigo, o autor apresenta e discute a importĆ¢ncia do pensamento de Anne Robert Jacques Turgot para a HistĆ³ria do Pensamento EconĆ“mico. Destaca seu brilhantismo intelectual, sua defesa da economia de mercado e do livre comĆ©rcio, e suas contribuiƧƵes protagonistas para as teorias do valor, das trocas, dos preƧos, da produĆ§Ć£o e da distribuiĆ§Ć£o

    A pentapeptide as minimal antigenic determinant for MHC class I-restricted T lymphocytes

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    Peptides that are antigenic for T lymphocytes are ligands for two receptors, the class I or II glycoproteins that are encoded by genes in the major histocompatibility complex, and the idiotypic / chain T-cell antigen receptor1ā€“9. That a peptide must bind to an MHC molecule to interact with a T-cell antigen receptor is the molecular basis of the MHC restriction of antigen-recognition by T lymphocytes10,11. In such a trimolecular interaction the amino-acid sequence of the peptide must specify the contact with both receptors: agretope residues bind to the MHC receptor and epitope residues bind to the T-cell antigen receptor12,13. From a compilation of known antigenic peptides, two algorithms have been proposed to predict antigenic sites in proteins. One algorithm uses linear motifs in the sequence14, whereas the other considers peptide conformation and predicts antigenicity for amphipathic -helices15,16. We report here that a systematic delimitation of an antigenic site precisely identifies a predicted pentapeptide motif as the minimal antigenic determinant presented by a class I MHC molecule and recognized by a cytolytic T lymphocyte clone

    Territorial rights and colonial wrongs

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    What is wrong with colonialism? The standardā€”albeit often implicitā€”answer to this question has been that colonialism was wrong because it violated the territorial rights of indigenous peoples, where territorial rights were grounded on acquisition theories. Recently, the standard view has come under attack: according to critics, acquisition based accounts do not provide solid theoretical grounds to condemn colonial relations. Indeed, historically they were used to justify colonialism. Various alternative accounts of the wrong of colonialism have been developed. According to some, colonialism involved a violation of territorial rights grounded on legitimate state theory. Others reject all explanations of colonialism's wrongfulness based on territorial rights, and argue that colonial practices were wrong because they departed from ideals of economic, social, and political association. In this article, we articulate and defend the standard view against critics: colonialism involved a procedural wrong; this wrong is not the violation of standards of equality and reciprocity, but the violation of territorial rights; and the best foundation for such territorial rights is acquisition based, not legitimacy based. We argue that this issue is not just of historical interest, it has relevant implications for the normative evaluation of contemporary inequalities

    Reciprocity as a foundation of financial economics

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    This paper argues that the subsistence of the fundamental theorem of contemporary financial mathematics is the ethical concept ā€˜reciprocityā€™. The argument is based on identifying an equivalence between the contemporary, and ostensibly ā€˜value neutralā€™, Fundamental Theory of Asset Pricing with theories of mathematical probability that emerged in the seventeenth century in the context of the ethical assessment of commercial contracts in a framework of Aristotelian ethics. This observation, the main claim of the paper, is justified on the basis of results from the Ultimatum Game and is analysed within a framework of Pragmatic philosophy. The analysis leads to the explanatory hypothesis that markets are centres of communicative action with reciprocity as a rule of discourse. The purpose of the paper is to reorientate financial economics to emphasise the objectives of cooperation and social cohesion and to this end, we offer specific policy advice

    Insulin-like Growth Factor II: An Essential Adult Stem Cell Niche Constituent in Brain and Intestine.

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    Tissue-specific stem cells have unique properties and growth requirements, but a small set of juxtacrine and paracrine signals have been identified that are required across multiple niches. Whereas insulin-like growth factor II (IGF-II) is necessary for prenatal growth, its role in adult stem cell physiology is largely unknown. We show that loss of Igf2 in adult mice resulted in a āˆ¼50% reduction in slowly dividing, label-retaining cells in the two regions of the brain that harbor neural stem cells. Concordantly, induced Igf2 deletion increased newly generated neurons in the olfactory bulb accompanied by hyposmia, and caused impairments in learning and memory and increased anxiety. Induced Igf2 deletion also resulted in rapid loss of stem and progenitor cells in the crypts of LieberkĆ¼hn, leading to body-weight loss and lethality and the inability to produce organoids inĀ vitro. These data demonstrate that IGF-II is critical for multiple adult stem cell niches

    Dynamic Measurements of Membrane Insertion Potential of Synthetic Cell Penetrating Peptides

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    This document is the Accepted Manuscript version of a Published Work that appeared in final form in Langmuir, copyright Ā© American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://doi.org/10.1021/la403370p.Cell penetrating peptides (CPPs) have been established as excellent candidates for mediating drug delivery into cells. When designing synthetic CPPs for drug delivery applications, it is important to understand their ability to penetrate the cell membrane. In this paper, anionic or zwitterionic phospholipid monolayers at the air-water interface are used as model cell membranes to monitor the membrane insertion potential of synthetic CPPs. The insertion potential of CPPs having different cationic and hydrophobic amino acids were recorded using a Langmuir monolayer approach that records peptide adsorption to model membranes. Fluorescence microscopy was used to visualize alterations in phospholipid packing due to peptide insertion. All CPPs had the highest penetration potential in the presence of anionic phospholipids. In addition, two of three amphiphilic CPPs inserted into zwitterionic phospholipids, but none of the hydrophilic CPPs did. All the CPPs studied induced disruptions in phospholipid packing and domain morphology, which were most pronounced for amphiphilic CPPs. Overall, small changes to amino acids and peptide sequences resulted in dramatically different insertion potentials and membrane reorganization. Designers of synthetic CPPs for efficient intracellular drug delivery should consider small nuances in CPP electrostatic and hydrophobic properties
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