4,461 research outputs found

    Learning Parameterized Skills

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    We introduce a method for constructing skills capable of solving tasks drawn from a distribution of parameterized reinforcement learning problems. The method draws example tasks from a distribution of interest and uses the corresponding learned policies to estimate the topology of the lower-dimensional piecewise-smooth manifold on which the skill policies lie. This manifold models how policy parameters change as task parameters vary. The method identifies the number of charts that compose the manifold and then applies non-linear regression in each chart to construct a parameterized skill by predicting policy parameters from task parameters. We evaluate our method on an underactuated simulated robotic arm tasked with learning to accurately throw darts at a parameterized target location.Comment: Appears in Proceedings of the 29th International Conference on Machine Learning (ICML 2012

    A Short Proof of Gamas's Theorem

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    If \chi^\lambda is the irreducible character of the symmetric group S_n corresponding to the partition \lambda of n then we may symmetrize a tensor v_1 \otimes ... \otimes v_n by \chi^\lambda. Gamas's theorem states that the result is not zero if and only if we can partition the set {v_i} into linearly independent sets whose sizes are the parts of the transpose of \lambda. We give a short and self-contained proof of this fact

    Equality of symmetrized tensors and the coordinate ring of the flag variety

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    In this note we give a transparent proof of a result of da Cruz and Dias da Silva on the equality of symmetrized decomposable tensors. This will be done by explaining that their result follows from the fact that the coordinate ring of a flag variety is a unique factorization domain.Comment: 5 page

    Upregulation of Transglutaminase andε(γ-Glutamyl)-Lysine in the Fisher-Lewis Rat Model of Chronic Allograft Nephropathy

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    Background. Tissue transglutaminase (TG2), a cross-linking enzyme, modulates deposition of extracellular matrix protein in renal fibrosis. This study aimed to examine TG2 and its cross-link product ε(γ-glutamyl)-lysine in the Fisher-Lewis rat renal transplantation (RTx) model of chronic allograft nephropathy (CAN). Materials and Methods. Left renal grafts from male Fisher and Lewis were transplanted into Lewis rats, generating allografts and isografts, respectively. Blood pressure, renal function, and proteinuria were monitored for up to 52 weeks. At termination, CAN was assessed in the renal tissue by light and electron microscopy, TG2 and ε(γ-glutamyl)-lysine by immunofluorescence, and the urinary ε(γ-glutamyl)-lysine by high performance liquid chromatography. Results. Compared to the isograft, the allografts were hypertensive, proteinuric, and uraemic and developed CAN. Extracellular TG2 (glomerulus: 64.55 + 17.61 versus 2.11 + 0.17, P<0.001; interstitium: 13.72 + 1.62 versus 3.19 + 0.44, P<0.001), ε(γ-glutamyl)-lysine (glomerulus: 21.74 + 2.71 versus 1.98 + 0.37, P<0.01; interstitium: 37.96 + 17.06 versus 0.42 + 0.11, P<0.05), TG2 enzyme activity (1.09 + 0.13 versus 0.41 + 0.03 nmol/h/mg protein, P<0.05), TG2 mRNA (20-fold rise), and urinary ε(γ-glutamyl)-lysine (534.2 + 198.4 nmol/24 h versus 57.2 + 4.1 nmol/24 h,P<0.05) levels were significantly elevated in the allografts and showed a positive linear correlation with tubulointerstitial fibrosis. Conclusion. CAN was associated with upregulation of renal TG2 pathway, which has a potential for pharmacological intervention. The elevated urinary ε(γ-glutamyl)-lysine, measured for the first time in RTx, is a potential biomarker of CA

    Plano de negócio : Somos Sol

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    Este trabalho tem por objetivo a elaboração de um plano de negócios para uma empresa de festas e eventos. O plano contêm todos os itens necessários para o entendimento, formação e viabilidade do empreendimento. Na primeira etapa são revisados conceitos relativos ao empreendedorismo, estrutura do plano de negócios e planejamento estratégico que servirão de suporte para o desenvolvimento do plano. Na segunda etapa, os conceitos e a estrutura são aplicados e é realizado o plano de negócios. Há a descrição da empresa, sua missão e visão, análise de mercado, objetivos e metas, posicionamento estratégico e análise financeira. Por fim, conclui-se que o negócio é viável como segunda fonte de renda até o momento em que seja atingido as metas estabelecidas, nesse momento será possível a disponibilidade em tempo integral de todos os sócios.This work aims to prepare a business plan for an event company. The plan contains all the items necessary for the understanding, formation and viability of the project. In the first stage, concepts related to entrepreneurship, the structure of the business plan and strategic planning that will support the development of the plan are reviewed. In the second stage, the concepts and structure are applied and the business plan is made. There is a description of the company, its mission and vision, market analysis, objectives and goals, strategic positioning and financial analysis. Finally, it is concluded that the business is viable as a second source of income until the established goals are reached, at that moment, full-time availability of all partners will be possibl

    How do patients from South Asian backgrounds experience life on haemodialysis in the UK? : A multicentre qualitative study

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    © Author(s) (or their employer(s)) 2018. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.OBJECTIVES: End-stage kidney disease disproportionately affects people of South Asian origin. This study aimed to uncover the lived experiences of this group of patients on centre-based haemodialysis (HD), the most prevalent dialysis modality. DESIGN: The study utilised a qualitative focus group methodology. Seven focus groups were conducted across four NHS Trusts in the UK including three in Gujarati and two each in Punjabi and Urdu. This provided an inclusive opportunity for South Asian patients to contribute in their language of origin. A total of 24 patients participated. Focus groups were facilitated by bilingual project workers and data were forward translated and analysed using thematic analysis. RESULTS: Four themes were identified. This included (1) 'treatment imposition', which comprised of the restrictive nature of HD, the effects of treatment and the feeling of being trapped in an endless process. (2) The 'patient-clinician relationship' centred around the impact of a perceived lack of staff time, and inadequacies in the quality of interactions. (3) 'Coping strategies' highlighted the role of cognitive reappraisal, living in the moment and family support networks in facilitating adjustment. (4) 'Pursuit of transplantation' included equating this form of treatment with restoring normality, alongside cultural factors limiting hopefulness for receiving an organ. CONCLUSIONS: In general, the experiences of South Asian patients receiving HD were not unique to this ethnic group. We did find distinct issues in relation to interactions with healthcare professionals, views on access to transplantation and the importance of family support networks. The study provides useful insights which may help enhance culturally tailored renal care.Peer reviewe

    Comparing Iconicity Trade-Offs in Cena and Libras during a Sign Language Production Task

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    Although classifier constructions generally aim for highly iconic depictions, like any other part of language they may be constrained by phonology. We compare utterances containing motion events between signers of Cena, an emerging rural sign language in Brazil, and Libras, the national sign language of Brazil, to investigate whether a difference in time-depth—a relevant factor in phonological reorganisation—influences trade-offs involving iconicity. First, we find that contrary to what may be expected, given that emerging sign languages exhibit great variation and favour highly iconic prototypes, Cena signers exhibit neither greater variation nor the use of more complex handshapes in classifier constructions. We also report a divergence from findings on Nicaraguan Sign Language (NSL) in how signers encode movement in a young language, showing that Cena signers tend to encode manner and path simultaneously, unlike NSL signers of comparable cohorts. Cena signers therefore pattern more like non-signing gesturers and signers of urban sign languages, including the Libras signers in our study. The study contributes an addition to the as-yet limited investigations into classifiers in emerging sign languages, demonstrating how different aspects of linguistic organisation, including phonology, can interact with classifier form
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