1,715 research outputs found

    On the monotone stability approach to BSDEs with jumps: Extensions, concrete criteria and examples

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    We show a concise extension of the monotone stability approach to backward stochastic differential equations (BSDEs) that are jointly driven by a Brownian motion and a random measure for jumps, which could be of infinite activity with a non-deterministic and time inhomogeneous compensator. The BSDE generator function can be non convex and needs not to satisfy global Lipschitz conditions in the jump integrand. We contribute concrete criteria, that are easy to verify, for results on existence and uniqueness of bounded solutions to BSDEs with jumps, and on comparison and a-priori L∞L^{\infty}-bounds. Several examples and counter examples are discussed to shed light on the scope and applicability of different assumptions, and we provide an overview of major applications in finance and optimal control.Comment: 28 pages. Added DOI https://link.springer.com/chapter/10.1007%2F978-3-030-22285-7_1 for final publication, corrected typo (missing gamma) in example 4.1

    Resolving the order parameter of High-Tc_{c} Superconductors through quantum pumping spectroscopy

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    The order parameter of High-Tc_{c} superconductors through a series of experiments has been quite conclusively demonstrated to not be of the normal sβˆ’waves-wave type. It is either a pure dx2βˆ’y2d_{x^{2}-y^{2}}-wave type or a mixture of a dx2βˆ’y2βˆ’waved_{x^{2}-y^{2}}-wave with a small imaginary sβˆ’waves-wave or dxyβˆ’waved_{xy}-wave component. In this work a distinction is brought out among the four types, i.e., sβˆ’waves- wave, dx2βˆ’y2βˆ’waved_{x^{2}-y^{2}}- wave, dx2βˆ’y2+isβˆ’waved_{x^{2}-y^{2}}+is - wave and dx2βˆ’y2+idxyβˆ’waved_{x^{2}-y^{2}}+id_{xy}- wave types with the help of quantum pumping spectroscopy. This involves a normal metal double barrier structure in contact with a High-Tc_{c} superconductor. The pumped current, heat and noise show different characteristics with change in order parameter revealing quite easily the differences among these.Comment: 11 pages, 3 figures, 1 table, Manuscript revised with new material on d+id' cas

    Ga+ Ion Irradiation-Induced Tuning of Artificial Pinning Sites to Control Domain Wall Motion

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    Domain-wall-based devices are considered one of the candidates for the next generation of storage memories and nanomagnetic logic devices due to their unique properties, such as nonvolatility, scalability, and low power consumption. Field or current-driven domain walls require a regular and controlled motion along the track in which they are stored in order to maintain the information integrity during operation. However, their dynamics can vary along the track due to film inhomogeneities, roughness of the edges, and thermal fluctuations. Consequently, the final position of the domain walls may be difficult to predict, making difficult the development of memory and logic applications. In this paper, we demonstrate how Ga+ ion irradiation can be used to locally modify the material properties of the Ta/ CoFeB/MgO thin film, creating regions in which the domain wall can be trapped, namely motion barriers. The aim is to push the domain wall to overcome thin-film inhomogeneities effects, while stopping its motion at artificially defined positions corresponding to the irradiated regions. Increasing the driving force strength, the domain wall can escape, allowing the shifting between consecutive irradiated regions. In this way, the correct positioning of the domain walls after the motion is ensured. The study shows that the driving force strength, namely current density or magnetic field amplitude, needed to overcome the irradiated regions depends on the ion dose. These results show a reliable approach for domain wall manipulation, enabling a precise control of the domain wall position along a track with synchronous motion

    Quadratic BSDEs driven by a continuous martingale and application to utility maximization problem

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    In this paper, we study a class of quadratic Backward Stochastic Differential Equations (BSDEs) which arises naturally when studying the problem of utility maximization with portfolio constraints. We first establish existence and uniqueness results for such BSDEs and then, we give an application to the utility maximization problem. Three cases of utility functions will be discussed: the exponential, power and logarithmic ones

    Quantifying Exocytosis by Combination of Membrane Capacitance Measurements and Total Internal Reflection Fluorescence Microscopy in Chromaffin Cells

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    Total internal reflection fluorescence microscopy (TIRF-Microscopy) allows the observation of individual secretory vesicles in real-time during exocytosis. In contrast to electrophysiological methods, such as membrane capacitance recording or carbon fiber amperometry, TIRF-Microscopy also enables the observation of vesicles as they reside close to the plasma membrane prior to fusion. However, TIRF-Microscopy is limited to the visualization of vesicles that are located near the membrane attached to the glass coverslip on which the cell grows. This has raised concerns as to whether exocytosis measured with TIRF-Microscopy is comparable to global secretion of the cell measured with membrane capacitance recording. Here we address this concern by combining TIRF-Microscopy and membrane capacitance recording to quantify exocytosis from adrenal chromaffin cells. We found that secretion measured with TIRF-Microscopy is representative of the overall secretion of the cells, thereby validating for the first time the TIRF method as a measure of secretion. Furthermore, the combination of these two techniques provides a new tool for investigating the molecular mechanism of synaptic transmission with combined electrophysiological and imaging techniques

    The National Dutch Breast Implant Registry: user-reported experiences and importance

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    Background: Robust (inter-)national breast implant registries are important. For some, registries are an administrative burden, for others they represent a solution for the discussions involving breast implants. The DBIR is one of the first national, opt-out, clinical registries of breast implants, providing information for clinical auditing and product recall. Four years after its introduction, it is time to address users’ comments in order to keep improving quality of registration, and patient safety. This study assesses users’ feedback focusing on importance of registration, logistics and user experience, and areas of improvement. Methods: In May 2018, a standardized online study–specific questionnaire was sent out to all members of the Netherlands Society of Plastic Surgery. Descriptive statistics were reported in absolute frequencies and/or percentages. Results: A total of 102 members responded to the questionnaire (response rate, 24.2%). Of all respondents, 97.1% were actively registering in DBIR. Respondents rated the importance of registration in DBIR as 8.1 out of 10 points. Ninety-one respondents suggested improvements for the DBIR. All comments were related to registration convenience and provision of automatically generated data. Conclusions: Respondents believe that registration is highly important and worth the administrative burden. However, we should collectively keep improving accuracy, usability and sustainability of breast

    Docking of LDCVs Is Modulated by Lower Intracellular [Ca2+] than Priming

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    Many regulatory steps precede final membrane fusion in neuroendocrine cells. Some parts of this preparatory cascade, including fusion and priming, are dependent on the intracellular Ca2+ concentration ([Ca2+]i). However, the functional implications of [Ca2+]i in the regulation of docking remain elusive and controversial due to an inability to determine the modulatory effect of [Ca2+]i. Using a combination of TIRF-microscopy and electrophysiology we followed the movement of large dense core vesicles (LDCVs) close to the plasma membrane, simultaneously measuring membrane capacitance and [Ca2+]i. We found that a free [Ca2+]i of 700 nM maximized the immediately releasable pool and minimized the lateral mobility of vesicles, which is consistent with a maximal increase of the pool size of primed LDCVs. The parameters that reflect docking, i.e. axial mobility and the fraction of LDCVs residing at the plasma membrane for less than 5 seconds, were strongly decreased at a free [Ca2+]i of 500 nM. These results provide the first evidence that docking and priming occur at different free intracellular Ca2+ concentrations, with docking efficiency being the most robust at 500 nM
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