2,198 research outputs found

    Disagreement about Inflation Expectations

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    Analyzing 50 years of inflation expectations data from several sources, we document substantial disagreement among both consumers and professional economists about expected future inflation. Moreover, this disagreement shows substantial variation through time, moving with inflation, the absolute value of the change in inflation, and relative price variability. We argue that a satisfactory model of economic dynamics must speak to these important business cycle moments. Noting that most macroeconomic models do not endogenously generate disagreement, we show that a simple sticky-information' model broadly matches many of these facts. Moreover, the sticky-information model is consistent with other observed departures of inflation expectations from full rationality, including autocorrelated forecast errors and insufficient sensitivity to recent macroeconomic news.

    Disagreement about Inflation Expectations

    Get PDF
    Analyzing 50 years of inflation expectations data from several sources, we document substantial disagreement among both consumers and professional economists about expected future inflation. Moreover, this disagreement shows substantial variation through time, moving with inflation, the absolute value of the change in inflation, and relative price variability. We argue that a satisfactory model of economic dynamics must speak to these important business cycle moments. Noting that most macroeconomic models do not endogenously generate disagreement, we show that a simple “sticky-information” model broadly matches many of these facts. Moreover, the sticky-information model is consistent with other observed departures of inflation expectations from full rationality, including autocorrelated forecast errors and insufficient sensitivity to recent macroeconomic news.

    Distributive Laws for Monotone Specifications

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    Turi and Plotkin introduced an elegant approach to structural operational semantics based on universal coalgebra, parametric in the type of syntax and the type of behaviour. Their framework includes abstract GSOS, a categorical generalisation of the classical GSOS rule format, as well as its categorical dual, coGSOS. Both formats are well behaved, in the sense that each specification has a unique model on which behavioural equivalence is a congruence. Unfortunately, the combination of the two formats does not feature these desirable properties. We show that monotone specifications - that disallow negative premises - do induce a canonical distributive law of a monad over a comonad, and therefore a unique, compositional interpretation.Comment: In Proceedings EXPRESS/SOS 2017, arXiv:1709.0004

    Reversing HOXA9 oncogene activation by PI3K inhibition: epigenetic mechanism and prognostic significance in human glioblastoma

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    HOXA genes encode critical transcriptional regulators of embryonic development that have been implicated in cancer. In this study, we documented functional relevance and mechanism of activation of HOXA9 in glioblastoma (GBM), the most common malignant brain tumor. Expression of HOXA genes was investigated using reverse transcription-PCR in primary gliomas and glioblastoma cell lines and was validated in two sets of expression array data. In a subset of GBM, HOXA genes are aberrently activated within confined chromosomal domains. Transcriptional activation of the HOXA cluster was reversible by a phosphoinostide 3-kinase (PI3K) inhibitor through an epigenetic mechanism involving histone H3K27 trimethylation. Functional studies of HOXA9 showed its capacity to decrease apoptosis and increase cellular proliferation along with tumor necrosis factor-related apoptosis-including ligand resistance. Notably, aberrant expression of HOXA9 was independently predictive of shorter overall and progression-free survival in two GBM patient sets and improved survival prediction by MGMT promoter methylation. Thus, HOXA9 activation is a novel, independent, and negative prognostic marker in GBM that is reversible through a PI3K-associated epigenetic mechanism. Our findings suggest a transcriptional pathway through which PI3K activates oncogenic HOXA expression with implications for mTOR or PI3K targeted therapies.NIH grants NIH CA094971 (J.F. Costello) and NIH/NCI F32 CA113039-01 (J.S. Smith); Karen Osney Brownstein Endowed Chair (J.F. Costello); UC Discovery grant Bio05-10501 (J.F. Costello and H.S. Phillips); Portuguese Science and Technology Foundation SFRH/BD/15258/2004 (B.M. Costa); and Luso-American Development Foundation, Portugal 186/06 (B.M. Costa

    The four dimensional site-diluted Ising model: a finite-size scaling study

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    Using finite-size scaling techniques, we study the critical properties of the site-diluted Ising model in four dimensions. We carry out a high statistics Monte Carlo simulation for several values of the dilution. The results support the perturbative scenario: there is only the Ising fixed point with large logarithmic scaling corrections. We obtain, using the Perturbative Renormalization Group, functional forms for the scaling of several observables that are in agreement with the numerical data.Comment: 30 pages, 8 postscript figure

    Nanostructured biopolymer/few-layer graphene freestanding films with enhanced mechanical and electrical properties

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    In the present work, novel freestanding multilayered films based on chitosan (CHI), alginate (ALG), and functionalized few-layer graphene are developed through layer-by-layer assembly. First, functionalized few-layer graphene aqueous suspensions are prepared from graphite by a stabilizer-assisted liquid phase exfoliation process, using a pyrene derivative as stabilizer. Afterward, the films are produced and their physical, morphological, thermal, and mechanical properties are evaluated. Furthermore, their degradation and swelling profiles, as well as their biological behavior, are assessed. The incorporation of functionalized few-layer graphene results in films with a nanolayered structure, lower roughness than the control CHI/ALG films, and hydrophilic behavior. The mechanical characterization reveals an increase of the Young's modulus, ultimate tensile strength, and elongation at break due to the incorporation of the graphene derivative. A decrease in the electrical resistivity of the multilayered films is also observed. The biological assays reveal improved cytocompatibility toward L929 cells when functionalized few-layer graphene is incorporated in the CHI/ALG matrix. Therefore, these new graphene-reinforced multilayered films exhibit interesting properties and great potential for biomedical applications, particularly in wound healing and cardiac and bone tissue engineering.The authors acknowledge the Portuguese Foundation for Science and Technology (FCT) and the European program FEDER/COMPETE for the financial support through projects UID/Multi/50026/2013 and UID/CTM/50025/2013. This work was also financially supported by FCT through the scholarships SFRH/BPD/96797/2013 granted to Sofia G. Caridade, SFRH/BD/97606/2013 granted to Maria P. Sousa, and SFRH/BD/87214/2012 granted to Eunice Cunh
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