622 research outputs found
A Mesoscopic Resonating Valence Bond system on a triple dot
We introduce a mesoscopic pendulum from a triple dot. The pendulum is
fastened through a singly-occupied dot (spin qubit). Two other strongly
capacitively islands form a double-dot charge qubit with one electron in excess
oscillating between the two low-energy charge states (1,0) and (0,1); this
embodies the weight of the pendulum. The triple dot is placed between two
superconducting leads as shown in Fig. 1. Under well-defined conditions, the
main proximity effect stems from the injection of resonating singlet (valence)
bonds on the triple dot. This gives rise to a Josephson current that is charge-
and spin-dependent. Consequences in a SQUID-geometry are carefully
investigated.Comment: final version to appear in PR
Business Capability Models : current landscape and next steps for the EUNIS community
Publisher Copyright: © 2022, EasyChair. All rights reserved.This paper takes a policy perspective on the development and governance of Business Capability Models in Higher Education. In particular, we look at the next steps in international collaboration around the Higher Education Reference Model (HERM) launched in 2021. The motivation is to highlight the European challenges and contributions to this concept. To do so, the paper draws on insights from the EUNIS EA SIG community. The paper also argues that ongoing work in the domain of interoperability underscores the importance of a common framework such as HERM. At the same time, EUNIS can build upon those experiences when collaborating on the development of HERM. The main recommendation of the paper is that EUNIS in general and the EA SIG, in particular, should actively engage in the future development of HERM. More specifically, we see a need to focus on the implications of translating the model into the broader European context.Peer reviewe
Dyninka: a FaaS framework for distributed dataflow applications
International audienceThe Internet of Things (IoT) requires applications to deal with a large amount of data-streamed, processed and stored from small devices to analytical systems. Cloud computing offers a hardware solution to this issue, providing ondemand resources to process IoT data. The newer programming paradigms simplify the use of those cloud resources. The Function-as-a-Service (FaaS) and the Serverless paradigm transform the conception of microservices applications to the definition and the composition of several callable functions. Although defined as distributed architectures-mostly publicly available solutions rely on either a gateway or an internal messaging middleware. These architectures create a single point of failure in exchange for more straightforward service to service communication. In this article, we present Dyninka, a framework to rapidly prototype FaaS-based distributed dataflow applications. Its programming model gathers the definition and the composition of services within a single file using the multitier programming paradigm and compiles them into a multitude of services deployable on cloud computing infrastructure. Dyninka is built without a gateway or a messaging platform, and services communicate directly with each other or with the cloud abstracted infrastructure. As a result, we reduce the network and the computation overheads introduced by commercial FaaS frameworks such as OpenFaaS. We validate Dyninka on a Fog computing scenario with limited resources and several load profiles. For all scenarios, Dyninka shows better stability, throughput and a reduced overhead compared to OpenFaaS
Information Loss in Coarse Graining of Polymer Configurations via Contact Matrices
Contact matrices provide a coarse grained description of the configuration
omega of a linear chain (polymer or random walk) on Z^n: C_{ij}(omega)=1 when
the distance between the position of the i-th and j-th step are less than or
equal to some distance "a" and C_{ij}(omega)=0 otherwise. We consider models in
which polymers of length N have weights corresponding to simple and
self-avoiding random walks, SRW and SAW, with "a" the minimal permissible
distance. We prove that to leading order in N, the number of matrices equals
the number of walks for SRW, but not for SAW. The coarse grained Shannon
entropies for SRW agree with the fine grained ones for n <= 2, but differs for
n >= 3.Comment: 18 pages, 2 figures, latex2e Main change: the introduction is
rewritten in a less formal way with the main results explained in simple
term
Prussian blue analogues for potassium-ion batteries: insights into the electrochemical mechanisms
A comprehensive description of the electrochemical mechanisms of the Prussian Blue Analogue (PBA) K1.67Mn0.65Fe0.35[Fe(CN)6]0.92\ub70.45H2O is obtained by combining several complementary ex situ and operando physico-chemical characterisation techniques. This particular PBA, which shows very good electrochemical performance as a cathode material in potassium-ion batteries (PIBs), undergoes three successive redox reactions during the (de-)potassiation that are hereby identified by ex situ57Fe M\uf6ssbauer spectroscopy and operando Mn and Fe K-edge X-ray absorption spectroscopy. These reactions come along with notable modifications of the crystal structure, which are followed in real time by operando X-ray diffraction. The correlation of these results, interpreted with the support of chemometric methods, also reveals the limitations of this PBA, probably related to the deactivation of the Mn undergoing extensive reversible Jahn-Teller distortion during cycling as well as possible dissolution in the electrolyte. These results underline that optimisation of the chemical composition of PBAs is a crucial step towards the preparation of reliable and stable PBA-based cathodes for PIBs
The Ideal Intersection Property for Groupoid Graded Rings
We show that if a groupoid graded ring has a certain nonzero ideal property,
then the commutant of the center of the principal component of the ring has the
ideal intersection property, that is it intersects nontrivially every nonzero
ideal of the ring. Furthermore, we show that for skew groupoid algebras with
commutative principal component, the principal component is maximal commutative
if and only if it has the ideal intersection property
Requirement of ÎČ1 integrin for endothelium-dependent vasodilation and collateral formation in hindlimb ischemia
An acute increase in blood flow triggers flow-mediated dilation (FMD), which is mainly mediated by
endothelial nitric oxide synthase (eNOS). A long-term increase in blood flow chronically enlarges the
arterial lumen, a process called arteriogenesis. In several common human diseases, these processes are
disrupted for as yet unknown reasons. Here, we asked whether ÎČ1 integrin, a mechanosensory protein in
endothelial cells, is required for FMD and arteriogenesis in the ischemic hindlimb. Permanent ligation of
the femoral artery in C57BL/6J mice enlarged pre-existing collateral arteries and increased numbers of
arterioles in the thigh. In the lower leg, the numbers of capillaries increased. Notably, injection of ÎČ1
integrin-blocking antibody or tamoxifen-induced endothelial cell-specific deletion of the gene for ÎČ1
integrin (Itgb1) inhibited both arteriogenesis and angiogenesis. Using high frequency ultrasound, we
demonstrated that ÎČ1 integrin-blocking antibody or endothelial cell-specific depletion of ÎČ1 integrin
attenuated FMD of the femoral artery, and blocking of ÎČ1 integrin function did not further decrease FMD in
eNOS-deficient mice. Our data suggest that endothelial ÎČ1 integrin is required for both acute and chronic
widening of the arterial lumen in response to hindlimb ischemia, potentially via functional interaction with
eNOS
Monotherapy efficacy of blood-brain barrier permeable small molecule reactivators of protein phosphatase 2A in glioblastoma
Glioblastoma is a fatal disease in which most targeted therapies have clinically failed. However, pharmacological reactivation of tumour suppressors has not been thoroughly studied as yet as a glioblastoma therapeutic strategy. Tumour suppressor protein phosphatase 2A is inhibited by non-genetic mechanisms in glioblastoma, and thus, it would be potentially amendable for therapeutic reactivation. Here, we demonstrate that small molecule activators of protein phosphatase 2A, NZ-8-061 and DBK-1154, effectively cross the in vitro model of blood-brain barrier, and in vivo partition to mouse brain tissue after oral dosing. In vitro, small molecule activators of protein phosphatase 2A exhibit robust cell-killing activity against five established glioblastoma cell lines, and nine patient-derived primary glioma cell lines. Collectively, these cell lines have heterogeneous genetic background, kinase inhibitor resistance profile and stemness properties; and they represent different clinical glioblastoma subtypes. Moreover, small molecule activators of protein phosphatase 2A were found to be superior to a range of kinase inhibitors in their capacity to kill patient-derived primary glioma cells. Oral dosing of either of the small molecule activators of protein phosphatase 2A significantly reduced growth of infiltrative intracranial glioblastoma tumours. DBK-1154, with both higher degree of brain/blood distribution, and more potent in vitro activity against all tested glioblastoma cell lines, also significantly increased survival of mice bearing orthotopic glioblastoma xenografts. In summary, this report presents a proof-of-principle data for blood-brain barrier-permeable tumour suppressor reactivation therapy for glioblastoma cells of heterogenous molecular background. These results also provide the first indications that protein phosphatase 2A reactivation might be able to challenge the current paradigm in glioblastoma therapies which has been strongly focused on targeting specific genetically altered cancer drivers with highly specific inhibitors. Based on demonstrated role for protein phosphatase 2A inhibition in glioblastoma cell drug resistance, small molecule activators of protein phosphatase 2A may prove to be beneficial in future glioblastoma combination therapies.Peer reviewe
High Harmonic Generation in Mixed Xuv and Nir Fields at a Free-Electron Laser
We Present the Results of an Experiment Investigating the Generation of High-Order Harmonics by a Femtosecond Near-Infrared (NIR) Laser Pulse in the Presence of an Extreme Ultraviolet (XUV) Field Provided by a Free-Electron Laser (FEL), a Process Referred to as XUV-Assisted High-Order Harmonic Generation (HHG). Our Experimental Findings Show that the XUV Field Can Lead to a Small Enhancement in the Harmonic Yield When the XUV and NIR Pulses overlap in Time, while a Strong Decrease of the HHG Yield and a Red Shift of the HHG Spectrum is Observed When the XUV Precedes the NIR Pulse. the Latter Observations Are in Qualitative Agreement with Model Calculations that Consider the Effect of a Decreased Number of Neutral Emitters but Are at Odds with the Predicted Effect of the Correspondingly Increased Ionization Fraction on the Phase Matching. Our Study Demonstrates the Technical Feasibility of XUV-Assisted HHG Experiments at FELs, Which May Provide New Avenues to Investigate Correlation-Driven Electron Dynamics as Well as Novel Ways to Study and Control Propagation Effects and Phase Matching in HHG
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