8,822 research outputs found

    Heat release by controlled continuous-time Markov jump processes

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    We derive the equations governing the protocols minimizing the heat released by a continuous-time Markov jump process on a one-dimensional countable state space during a transition between assigned initial and final probability distributions in a finite time horizon. In particular, we identify the hypotheses on the transition rates under which the optimal control strategy and the probability distribution of the Markov jump problem obey a system of differential equations of Hamilton-Bellman-Jacobi-type. As the state-space mesh tends to zero, these equations converge to those satisfied by the diffusion process minimizing the heat released in the Langevin formulation of the same problem. We also show that in full analogy with the continuum case, heat minimization is equivalent to entropy production minimization. Thus, our results may be interpreted as a refined version of the second law of thermodynamics.Comment: final version, section 2.1 revised, 26 pages, 3 figure

    Stand-alone wearable system for ubiquitous real-time monitoring of muscle activation potentials

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    Wearable technology is attracting most attention in healthcare for the acquisition of physiological signals. We propose a stand-alone wearable surface ElectroMyoGraphy (sEMG) system for monitoring the muscle activity in real time. With respect to other wearable sEMG devices, the proposed system includes circuits for detecting the muscle activation potentials and it embeds the complete real-time data processing, without using any external device. The system is optimized with respect to power consumption, with a measured battery life that allows for monitoring the activity during the day. Thanks to its compactness and energy autonomy, it can be used outdoor and it provides a pathway to valuable diagnostic data sets for patients during their own day-life. Our system has performances that are comparable to state-of-art wired equipment in the detection of muscle contractions with the advantage of being wearable, compact, and ubiquitous

    Gotham Fights Back: The Role of U.S. Cities in Advancing Paris Agreement Goals

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    Crossing the Bridge of Size: Reaching a Deal at Nice

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    The Intergovernmental Conference which should conclude at Nice in December 2000 deals with issues of institutional reform which must be resolved before proceeding with enlargement. There are four main questions. Should all countries be able to name a Member of the European Commission, or should the number of Commissioners be ‘capped’ at a number lower than the number of Member States? How should the weighting of Member States’ votes in the Council be adjusted to ensure that winning coalitions under qualified-majority voting represent an adequate proportion of the total EU population – as well as to ‘compensate’ those five Member States which lose their second Commissioner? How far should qualified-majority voting be extended? Should the conditions for ‘closer cooperation’ be relaxed to make it easier to press ahead with integration in particular areas without the participation of all Member States? A deal must be reached at Nice, but the IGC has revealed serious differences between the Member States. There is likely to be an agreement: for one Commissioner per Member State, probably with an internal hierarchy; a significant reweighting of votes in favour of the big Member States; a moderate extension of qualified-majority voting; and at least the removal of the veto regarding closer cooperation. Yet relative size has emerged as a source of frictions and concerns about long-term solidarity. The big countries fear being tied down. The smaller ones have long-term concerns about being dominated or absorbed, as well as presentational problems. If all the results of the IGC are seen as concessions to the large countries, it will be hard to sell the Nice Treaty at home – and Denmark has again shown that people can say No. Too much intergovernmentalism is not the answer. The Community institutions cannot do everything, but they have played an essential role in overcoming fears about relative power. They need to be renewed, not replaced

    Differentiation of human induced pluripotent stem cells into cortical neural stem cells

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    Efficient and effective methods for converting human induced pluripotent stem cells into differentiated derivatives are critical for performing robust, large-scale studies of development and disease modelling, and for providing a source of cells for regenerative medicine. Here, we describe a 14-day neural differentiation protocol which allows for the scalable, simultaneous differentiation of multiple iPSC lines into cortical neural stem cells We currently employ this protocol to differentiate and compare sets of engineered iPSC lines carrying loss of function alleles in developmental disorder associated genes, alongside isogenic wildtype controls. Using RNA sequencing (RNA-Seq), we can examine the changes in gene expression brought about by each disease gene knockout, to determine its impact on neural development and explore mechanisms of disease. The 10-day Neural Induction period uses the well established dual-SMAD inhibition approach combined with Wnt/beta-Catenin inhibition to selectively induce formation of cortical NSCs. This is followed by a 4-day Neural Maintenance period facilitating NSC expansion and rosette formation, and NSC cryopreservation. We also describe methods for thawing and passaging the cryopreserved NSCs, which are useful in confirming their viability for further culture. Routine implementation of immunocytochemistry Quality Control confirms the presence of PAX6-positive and/or FOXG1-positive NSCs and the absence of OCT4-positive iPSCs after differentiation. RNA-Seq, flow cytometry, immunocytochemistry (ICC) and RT-qPCR provide additional confirmation of robust presence of NSC markers in the differentiated cells. The broader utility and application of our protocol is demonstrated by the successful differentiation of wildtype iPSC lines from five additional independent donors. This paper thereby describes an efficient method for the production of large numbers of high purity cortical NSCs, which are widely applicable for downstream research into developmental mechanisms, further differentiation into postmitotic cortical neurons, or other applications such as large-scale drug screening experiments.Peer reviewe
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