Primary left atrial haemangioendothelioma

We describe the case of a 21-year-old female patient with epithelioid haemangioendothelioma of the roof of the left atrium. The patient underwent radical resection of the tumour with large disease-free margins, which required reconstruction of left and right atrial superior walls. The prognosis is unpredictable, but life expectancies ranging from 1 to 20 years have been described. There is no single treatment that can be prescribed but, because of their biologic behaviour, epithelioid haemangioendotheliomas must be regarded as fully malignant neoplasms and ought to be resected radically to prevent metastatic disease, and to improve life expectancy and quality of life

Molecular Gas, Dust and Star Formation in Galaxies: II. Dust properties and scalings in \sim\ 1600 nearby galaxies

We aim to characterize the relationship between dust properties. We also aim to provide equations to estimate accurate dust properties from limited observational datasets. We assemble a sample of 1,630 nearby (z<0.1) galaxies-over a large range of Mstar, SFR - with multi-wavelength observations available from wise, iras, planck and/or SCUBA. The characterization of dust emission comes from SED fitting using Draine & Li dust models, which we parametrize using two components (warm and cold ). The subsample of these galaxies with global measurements of CO and/or HI are used to explore the molecular and/or atomic gas content of the galaxies. The total Lir, Mdust and dust temperature of the cold component (Tc) form a plane that we refer to as the dust plane. A galaxy's sSFR drives its position on the dust plane: starburst galaxies show higher Lir, Mdust and Tc compared to Main Sequence and passive galaxies. Starburst galaxies also show higher specific Mdust (Mdust/Mstar) and specific Mgas (Mgas/Mstar). The Mdust is more closely correlated with the total Mgas (atomic plus molecular) than with the individual components. Our multi wavelength data allows us to define several equations to estimate Lir, Mdust and Tc from one or two monochromatic luminosities in the infrared and/or sub-millimeter. We estimate the dust mass and infrared luminosity from a single monochromatic luminosity within the R-J tail of the dust emission, with errors of 0.12 and 0.20dex, respectively. These errors are reduced to 0.05 and 0.10 dex, respectively, if the Tc is used. The Mdust is correlated with the total Mism (Mism \propto Mdust^0.7). For galaxies with Mstar 8.5<log(Mstar/Msun) < 11.9, the conversion factor \alpha_850mum shows a large scatter (rms=0.29dex). The SF mode of a galaxy shows a correlation with both the Mgass and Mdust: high Mdust/Mstar galaxies are gas-rich and show the highest SFRs.Comment: 24 pages, 28 figures, 6 tables, Accepted for publication in A&

The MADP Toolbox: An Open-Source Library for Planning and Learning in (Multi-)Agent Systems

This article describes the MultiAgent Decision Process (MADP) toolbox, a software library to support planning and learning for intelligent agents and multiagent systems in un- certain environments. Some of its key features are that it sup- ports partially observable environments and stochastic tran- sition models; has unified support for single- and multiagent systems; provides a large number of models for decision- theoretic decision making, including one-shot decision mak- ing (e.g., Bayesian games) and sequential decision mak- ing under various assumptions of observability and coopera- tion, such as Dec-POMDPs and POSGs; provides tools and parsers to quickly prototype new problems; provides an ex- tensive range of planning and learning algorithms for single- and multiagent systems; and is written in C++ and designed to be extensible via the object-oriented paradigm

Modeling Coordinated vs. P2P Mining: An Analysis of Inefficiency and Inequality in Proof-of-Work Blockchains

We study efficiency in a proof-of-work blockchain with non-zero latencies, focusing in particular on the (inequality in) individual miners' efficiencies. Prior work attributed differences in miners' efficiencies mostly to attacks, but we pursue a different question: Can inequality in miners' efficiencies be explained by delays, even when all miners are honest? Traditionally, such efficiency-related questions were tackled only at the level of the overall system, and in a peer-to-peer (P2P) setting where miners directly connect to one another. Despite it being common today for miners to pool compute capacities in a mining pool managed by a centralized coordinator, efficiency in such a coordinated setting has barely been studied. In this paper, we propose a simple model of a proof-of-work blockchain with latencies for both the P2P and the coordinated settings. We derive a closed-form expression for the efficiency in the coordinated setting with an arbitrary number of miners and arbitrary latencies, both for the overall system and for each individual miner. We leverage this result to show that inequalities arise from variability in the delays, but that if all miners are equidistant from the coordinator, they have equal efficiency irrespective of their compute capacities. We then prove that, under a natural consistency condition, the overall system efficiency in the P2P setting is higher than that in the coordinated setting. Finally, we perform a simulation-based study to demonstrate that even in the P2P setting delays between miners introduce inequalities, and that there is a more complex interplay between delays and compute capacities

Understanding Blockchain Governance: Analyzing Decentralized Voting to Amend DeFi Smart Contracts

Smart contracts are contractual agreements between participants of a blockchain, who cannot implicitly trust one another. They are software programs that run on top of a blockchain, and we may need to change them from time to time (e.g., to fix bugs or address new use cases). Governance protocols define the means for amending or changing these smart contracts without any centralized authority. They distribute instead the decision-making power to every user of the smart contract: Users vote on accepting or rejecting every change. The focus of this work is to evaluate whether, how, and to what extent these protocols ensure decentralized governance, the fundamental tenet of blockchains, in practice. This evaluation is crucial as smart contracts continue to transform our key, traditional, centralized institutions, particularly banking and finance. In this work, we review and characterize decentralized governance in practice, using Compound -- one of the widely used governance protocols -- as a case study. We reveal a high concentration of voting power in Compound: 10 voters hold together 57.86% of the voting power. Although proposals to change or amend the protocol (or, essentially, the application they support) receive, on average, a substantial number of votes (i.e., 89.39%) in favor, they require fewer than three voters to obtain 50% or more votes. We show that voting on Compound governance proposals can be unfairly expensive for small token holders, and also discover voting coalitions that can further marginalize these users. We plan on publishing our scripts and data set on GitHub to support reproducible research.Comment: We have submitted this work for publication and are currently awaiting a decisio

Dissecting Bitcoin and Ethereum Transactions: On the Lack of Transaction Contention and Prioritization Transparency in Blockchains

In permissionless blockchains, transaction issuers include a fee to incentivize miners to include their transaction. To accurately estimate this prioritization fee for a transaction, transaction issuers (or blockchain participants, more generally) rely on two fundamental notions of transparency, namely contention and prioritization transparency. Contention transparency implies that participants are aware of every pending transaction that will contend with a given transaction for inclusion. Prioritization transparency states that the participants are aware of the transaction or prioritization fees paid by every such contending transaction. Neither of these notions of transparency holds well today. Private relay networks, for instance, allow users to send transactions privately to miners. Besides, users can offer fees to miners via either direct transfers to miners' wallets or off-chain payments -- neither of which are public. In this work, we characterize the lack of contention and prioritization transparency in Bitcoin and Ethereum resulting from such practices. We show that private relay networks are widely used and private transactions are quite prevalent. We show that the lack of transparency facilitates miners to collude and overcharge users who may use these private relay networks despite them offering little to no guarantees on transaction prioritization. The lack of these transparencies in blockchains has crucial implications for transaction issuers as well as the stability of blockchains. Finally, we make our data sets and scripts publicly available.Comment: This is a pre-print of our paper accepted to appear to the Financial Cryptography and Data Security 2023 (FC '23

Circulation, retention, and mixing of waters within the Weddell-Scotia Confluence, Southern Ocean:The role of stratified Taylor columns

The waters of the Weddell-Scotia Confluence (WSC) lie above the rugged topography of the South Scotia Ridge in the Southern Ocean. Meridional exchanges across the WSC transfer water and tracers between the Antarctic Circumpolar Current (ACC) to the north and the subpolar Weddell Gyre to the south. Here, we examine the role of topographic interactions in mediating these exchanges, and in modifying the waters transferred. A case study is presented using data from a free-drifting, intermediate-depth float, which circulated anticyclonically over Discovery Bank on the South Scotia Ridge for close to 4 years. Dimensional analysis indicates that the local conditions are conducive to the formation of Taylor columns. Contemporaneous ship-derived transient tracer data enable estimation of the rate of isopycnal mixing associated with this column, with values of O(1000 m2/s) obtained. Although necessarily coarse, this is of the same order as the rate of isopycnal mixing induced by transient mesoscale eddies within the ACC. A picture emerges of the Taylor column acting as a slow, steady blender, retaining the waters in the vicinity of the WSC for lengthy periods during which they can be subject to significant modification. A full regional float data set, bathymetric data, and a Southern Ocean state estimate are used to identify other potential sites for Taylor column formation. We find that they are likely to be sufficiently widespread to exert a significant influence on water mass modification and meridional fluxes across the southern edge of the ACC in this sector of the Southern Ocean

Functional respiratory re-education interventions in people with respiratory disease: a systematic literature review

Objectives: to identify nursing interventions in rehabilitation, within the scope of functional respiratory reeducation, which allow a respiratory function improvement in people with respiratory disease. Methods: systematic literature review using the MEDLINE database search, adopting the PICO mnemonic and the Joanna Briggs Institute’s assessment of the level of evidence and methodological quality. The search for randomized controlled trials was carried out in June 2021 considering the period from 2015 to 2020, in English or Portuguese. Results: a sample of nine randomized controlled trials with methodological quality was obtained which highlighted the use of positive expiratory pressure devices as an importantcomponent and intervention for respiratory functional reeducation. Conclusions: nursing interventions in rehabilitation with an emphasis on functional respiratory reeducation are essential, showing improvements in people’s general health

EDMOND ORBAN, Le fédéralisme ? Super État fédéral ? Association d'États souverains ?, Montréal, Hurtubise HMH, 1992, 170 p., ISBN 2-89045-968-3.

(Papilionoideae (Leguminosae) dos campos ferruginosos do Parque Estadual do Itacolomi, MG). Foi realizado um levantamento florístico das espécies de Papilionoideae (Leguminosae) ocorrentes nos campos ferruginosos do Parque Estadual do Itacolomi (PEI), situado nos municípios de Ouro Preto e Mariana, estado de Minas Gerais. As coletas foram feitas no período de março de 2001 a maio de 2002. Foram identificadas 20 espécies de Papilionoideae, pertencentes a 13 gêneros. Os gêneros mais representativos em número de espécies foram Desmodium (4), Crotalaria (3), Machaerium e Stylosanthes, com duas espécies cada. Os demais gêneros foram representados por apenas uma espécie cada. No estudo fenológico das espécies, foram constatadas correlações entre fatores climáticos (temperatura e precipitação) e a perda de folhas, brotação, floração e frutificação.(Papilionoideae (Leguminosae) of “campos ferruginosos” of Itacolomi State Park, Minas Gerais, Brazil). A floristic survey of Papilionoideae species was carried out in “campos ferruginosos” of Itacolomy State Park (PEI), situated between Ouro Preto and Mariana cities, Minas Gerais. The collections was made from March, 2001 to May, 2002. Twenty species of 13 genera of Papilionoideae were identified. The genera that had more representative number of species were Desmodium (4), Crotalaria (3), Machaerium (2) and Stylosanthes (2). The others had only one specie each. In the phenological study of the species, correlations between environmental parameters (temperature and rainfall) and the leaf fall, leaf flushing, flowering and the fruiting were verified