The Electronic and Superconducting Properties of Oxygen-Ordered MgB2 compounds of the form Mg2B3Ox

Possible candidates for the Mg2B3Ox nanostructures observed in bulk of polycrystalline MgB2 (Ref.1) have been studied using a combination of Z-contrast imaging, electron energy loss spectroscopy (EELS) and first-principles calculations. The electronic structures, phonon modes, and electron phonon coupling parameters are calculated for two oxygen-ordered MgB2 compounds of composition Mg2B3O and Mg2B3O2, and compared with those of MgB2. We find that the density of states for both Mg2B3Ox structures show very good agreement with EELS, indicating that they are excellent candidates to explain the observed coherent oxygen precipitates. Incorporation of oxygen reduces the transition temperature and gives calculated TC values of 18.3 K and 1.6 K for Mg2B3O and Mg2B3O2, respectively.Comment: Submitted to PR

Diagnostic Communication in the Memory Clinic: a Conversation Analytic Perspective

Objectives: Whether and how patients should be told their dementia diagnosis, has been an area of much debate. While there is now recognition that early diagnosis is important for dementia care little research has looked at how dementia-related diagnostic information is actually verbally communicated. The limited previous research suggests that the absence of explicit terminology (e.g., use of the term Alzheimer's) is problematic. This paper interrogates this assumption through a conversation analysis of British naturalistic memory clinic interaction. Method: This paper is based on video-recordings of communication within a UK memory clinic. Appointments with 29 patients and accompanying persons were recorded, and the corpus was repeatedly listened to, in conjunction with the transcripts in order to identify the segments of talk where there was an action hearable as diagnostic delivery, that is where the clinician is evaluating the patient's condition. Results: Using a conversation analytic approach this analysis suggests that diagnostic communication, which is sensitive and responsive to the patient and their carers, is not predicated on the presence or absence of particular lexical choices. There is inherent complexity regarding dementia diagnosis, especially in the ‘early stages’, which is produced through and reflected in diagnostic talk in clinical encounters. Conclusion: In the context of continuity of dementia care, diagnostic information is communicated in a way that conforms to intersubjective norms of minimizing catastrophic reactions in medical communication, and is sensitive to problems associated with ‘insight’ in terms of delivery and receipt or non-receipt of diagnosis

O expletivo ele em domínios dependentes em português europeu

Tese de mestrado, Linguística, Universidade de Lisboa, Faculdade de Letras, 2013Esta dissertação tem como objeto de estudo a distribuição do expletivo ele nãopadrão em domínios oracionais dependentes em português europeu. Partindo de uma caracterização do expletivo ele como elemento linguístico relacionado com posições sintáticas na periferia esquerda da frase, a investigação aqui apresentada centra-se sobre a descrição sintática dos contextos dependentes que envolvem este expletivo, a fim de verificar: a posição ocupada por ele na periferia esquerda de domínios oracionais nãomatriz, a ocorrência de simetrias/assimetrias na distribuição e nos efeitos discursivos do expletivo em orações dependentes relativamente às propriedades atribuídas a este expletivo em orações principais. Neste sentido, a presente investigação visa também contribuir para o estudo comparativo da estrutura da periferia esquerda em frases principais e em frases dependentes. A base empírica aqui apresentada incide sobre dados de variedades não-padrão do português europeu recolhidos do Corpus Dialectal para o Estudo da Sintaxe (CORDIAL-SIN), desenvolvido pelo Centro de Linguística da Universidade de Lisboa. No plano da distribuição sintática, em orações dependentes, dois tipos de expletivo são distinguidos: o expletivo pré-verbal, que ocorre em posição pré ou pósconector e que pode ser associado a uma projeção ForceP na periferia esquerda da estrutura frásica, ou no domínio da oração dependente ou no domínio matriz de uma oração dependente periférica; pontualmente, o expletivo pós-verbal, que aparece em uma posição mais baixa. A presença do expletivo ele em contextos não-matriz manifesta propriedades discursivas enfáticas relevantes para a codificação de efeitos ilocutórios, em muitos dos exemplos analisados associáveis a domínios dependentes assertivos.Abstract The object of the study in this dissertation consists of the distribution of nonstandard expletive ele in dependent clausal domains in European Portuguese. Based on a characterization of the expletive ele as a linguistic element related to syntactic positions on the left periphery of the sentence, the research presented here focuses on the syntactical description of dependents contexts involving this expletive, in order to examine: the position occupied by ele in left periphery of non matrix clausal domains, the occurrence of symmetry/asymmetry in the distribution and discursive effects of the expletive in dependent clauses regarding the properties attributed to this expletive in main clauses. In this sense, this research also aims to contribute to the comparative study of the left periphery structure in main clauses and dependents phrases. The empirical study presented here focuses on non-standard European Portuguese data collected from the Syntax-oriented Corpus of Portuguese Dialects (CORDIAL-SIN), developed by the Centro de Linguística da Universidade de Lisboa. In terms of syntactic distribution, in dependents clauses, two expletive types are distinguished: the preverbal expletive, which occurs in a pre or post-connector position and can be associated with a ForceP projection in the left periphery of the sentence, either in dependents clauses or in the matrix clause domain of a peripheral dependent clause; and, occasionally, a post verbal expletive, which appears in a lower position. The presence of the expletive ele in non-matrix contexts shows discursive properties relevant to codify illocutionary effects, and in many examples it can be associated with assertive dependents domains

LNCS

Discrete-time Markov Chains (MCs) and Markov Decision Processes (MDPs) are two standard formalisms in system analysis. Their main associated quantitative objectives are hitting probabilities, discounted sum, and mean payoff. Although there are many techniques for computing these objectives in general MCs/MDPs, they have not been thoroughly studied in terms of parameterized algorithms, particularly when treewidth is used as the parameter. This is in sharp contrast to qualitative objectives for MCs, MDPs and graph games, for which treewidth-based algorithms yield significant complexity improvements. In this work, we show that treewidth can also be used to obtain faster algorithms for the quantitative problems. For an MC with n states and m transitions, we show that each of the classical quantitative objectives can be computed in O((n+m)⋅t2) time, given a tree decomposition of the MC with width t. Our results also imply a bound of O(κ⋅(n+m)⋅t2) for each objective on MDPs, where κ is the number of strategy-iteration refinements required for the given input and objective. Finally, we make an experimental evaluation of our new algorithms on low-treewidth MCs and MDPs obtained from the DaCapo benchmark suite. Our experiments show that on low-treewidth MCs and MDPs, our algorithms outperform existing well-established methods by one or more orders of magnitude

An Ordered Approach to Solving Parity Games in Quasi-Polynomial Time and Quasi-Linear Space

Parity games play an important role in model checking and synthesis. In their paper, Calude et al. have recently shown that these games can be solved in quasi-polynomial time. We show that their algorithm can be implemented efficiently: we use their data structure as a progress measure, allowing for a backward implementation instead of a complete unravelling of the game. To achieve this, a number of changes have to be made to their techniques, where the main one is to add power to the antagonistic player that allows for determining her rational move without changing the outcome of the game. We provide a first implementation for a quasi-polynomial algorithm, test it on small examples, and provide a number of side results, including minor algorithmic improvements, a quasi-bi-linear complexity in the number of states and edges for a fixed number of colours, matching lower bounds for the algorithm of Calude et al., and a complexity index associated to our approach, which we compare to the recently proposed register index

Stevin numbers and reality

We explore the potential of Simon Stevin's numbers, obscured by shifting foundational biases and by 19th century developments in the arithmetisation of analysis.Comment: 22 pages, 4 figures. arXiv admin note: text overlap with arXiv:1104.0375, arXiv:1108.2885, arXiv:1108.420

Actin and myosin contribute to mammalian mitochondrial DNA maintenance.

Mitochondrial DNA maintenance and segregation are dependent on the actin cytoskeleton in budding yeast. We found two cytoskeletal proteins among six proteins tightly associated with rat liver mitochondrial DNA: non-muscle myosin heavy chain IIA and β-actin. In human cells, transient gene silencing of MYH9 (encoding non-muscle myosin heavy chain IIA), or the closely related MYH10 gene (encoding non-muscle myosin heavy chain IIB), altered the topology and increased the copy number of mitochondrial DNA; and the latter effect was enhanced when both genes were targeted simultaneously. In contrast, genetic ablation of non-muscle myosin IIB was associated with a 60% decrease in mitochondrial DNA copy number in mouse embryonic fibroblasts, compared to control cells. Gene silencing of β-actin also affected mitochondrial DNA copy number and organization. Protease-protection experiments and iodixanol gradient analysis suggest some β-actin and non-muscle myosin heavy chain IIA reside within human mitochondria and confirm that they are associated with mitochondrial DNA. Collectively, these results strongly implicate the actomyosin cytoskeleton in mammalian mitochondrial DNA maintenance.Medical Research Council; the European Union; the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development and National Heart; Lung and Blood Institute; National Institutes of Health and grants [CMRPG360491-2, 380651, NSC 97-2321-B-182A-002-MY2] from the Chang Gung Memorial Hospital, Lin-Kou, Taiwan (to C.C.M.). Funding for open access charge: Medical Research Council

Identification and quantification of protein S-nitrosation by nitrite in the mouse heart during ischemia.

Nitrate (NO3-) and nitrite (NO2-) are known to be cardioprotective and to alter energy metabolism in vivo NO3- action results from its conversion to NO2- by salivary bacteria, but the mechanism(s) by which NO2- affects metabolism remains obscure. NO2- may act by S-nitrosating protein thiols, thereby altering protein activity. But how this occurs, and the functional importance of S-nitrosation sites across the mammalian proteome, remain largely uncharacterized. Here we analyzed protein thiols within mouse hearts in vivo using quantitative proteomics to determine S-nitrosation site occupancy. We extended the thiol-redox proteomic technique, isotope-coded affinity tag labeling, to quantify the extent of NO2--dependent S-nitrosation of proteins thiols in vivo Using this approach, called SNOxICAT (S-nitrosothiol redox isotope-coded affinity tag), we found that exposure to NO2- under normoxic conditions or exposure to ischemia alone results in minimal S-nitrosation of protein thiols. However, exposure to NO2- in conjunction with ischemia led to extensive S-nitrosation of protein thiols across all cellular compartments. Several mitochondrial protein thiols exposed to the mitochondrial matrix were selectively S-nitrosated under these conditions, potentially contributing to the beneficial effects of NO2- on mitochondrial metabolism. The permeability of the mitochondrial inner membrane to HNO2, but not to NO2-, combined with the lack of S-nitrosation during anoxia alone or by NO2- during normoxia places constraints on how S-nitrosation occurs in vivo and on its mechanisms of cardioprotection and modulation of energy metabolism. Quantifying S-nitrosated protein thiols now allows determination of modified cysteines across the proteome and identification of those most likely responsible for the functional consequences of NO2- exposure

Ten Misconceptions from the History of Analysis and Their Debunking

The widespread idea that infinitesimals were "eliminated" by the "great triumvirate" of Cantor, Dedekind, and Weierstrass is refuted by an uninterrupted chain of work on infinitesimal-enriched number systems. The elimination claim is an oversimplification created by triumvirate followers, who tend to view the history of analysis as a pre-ordained march toward the radiant future of Weierstrassian epsilontics. In the present text, we document distortions of the history of analysis stemming from the triumvirate ideology of ontological minimalism, which identified the continuum with a single number system. Such anachronistic distortions characterize the received interpretation of Stevin, Leibniz, d'Alembert, Cauchy, and others.Comment: 46 pages, 4 figures; Foundations of Science (2012). arXiv admin note: text overlap with arXiv:1108.2885 and arXiv:1110.545