Synchronized single electron emission from dynamical quantum dots

We study synchronized quantized charge pumping through several dynamical quantum dots (QDs) driven by a single time modulated gate signal. We show that the main obstacle for synchronization being the lack of uniformity can be overcome by operating the QDs in the decay cascade regime. We discuss the mechanism responsible for lifting the stringent uniformity requirements. This enhanced functionality of dynamical QDs might find applications in nanoelectronics and quantum metrology.Comment: 4 pages, 3 figures, submitted to AP

Elastic precession of electronic spin states in interacting integer quantum Hall edge channels

We consider the effect of Coulomb interactions in the propagation of electrons, prepared in arbitrary spin states, on chiral edge channels in the integer quantum Hall regime. Electrons are injected and detected at the same energy at different locations of the Hall bar, which is modeled as a chiral Tomonaga-Luttinger liquid. The current is computed perturbatively in the tunneling amplitudes, within a non-crossing approximation using exact solutions of the interacting Green's functions. In the case of different channel velocities, the spin precession effect is evaluated, and the role of interaction parameters and wavevectors is discussed.Comment: 5 pages, 3 figure

Prostaglandin E Positively Modulates Endothelial Progenitor Cell Homeostasis: An Advanced Treatment Modality for Autologous Cell Therapy

Aims: The mobilization of endothelial progenitor cells (EPC) and their functioning in postnatal neovascularization are tightly regulated. To identify new modulators of EPC homeostasis, we screened biologically active prostaglandin E compounds for their effects on EPC production, trafficking and function. Methods and Results: We found that EPC are a rich source for prostaglandin E 2 (PGE 2), stimulating their number and function in an auto- and paracrine manner. In vivo blockade of PGE 2 production by selective cyclooxygenase-2 inhibition virtually abrogated ischemia-induced EPC mobilization demonstrating its crucial role in EPC homeostasis following tissue ischemia. Conversely, ex vivo treatment of isolated EPC with the clinically approved PGE 1 analogue alprostadil enhanced EPC number and function. These effects were mediated by increased expression of the chemokine receptor CXCR4 and were dependent on nitric oxide synthase activity. Most importantly, ex vivo PGE 1 pretreatment of isolated EPC significantly enhanced their neovascularization capacity in a murine model of hind limb ischemia as assessed by laser Doppler analysis, exercise stress test and immunohistochemistry. Conclusions: The conserved role for PGE in the regulation of EPC homeostasis suggests that ex vivo modulation of the prostaglandin pathway in isolated progenitor cells may represent a novel and safe strategy to facilitate cell-based therapies. Copyright (C) 2009 S. Karger AG, Base

Game-play characteristics differ between the European Super League and National Rugby League: Implications for coaching and talent recruitment

Objectives: To compare the game-play characteristics between the European Super League (ESL) and the National Rugby League (NRL) competitions. Methods: Eleven team performance indicators were extracted from each match played by every ESL and NRL team over their respective 2016 season. Data was averaged, classified according to competition (Two levels: ESL and NRL), and modelled using univariate and multivariate techniques. Specifically, effect size statistics enabled between group comparisons, while non-metric multidimensional scaling enabled multivariate insights into competition dissimilarity. Results: Seven of the 11 performance indicators showed ‘large’ to ‘very large’ effects. Notably, NRL game-play generated fewer ‘line breaks’, ‘errors’, ‘tackles’ and ‘dummy half runs’ relative to ESL game-play (d >1.2). Despite the NRL generating fewer ‘all runs’ (d = 1.27 [0.57-1.95]), game-play in this competition generated greater ‘all run distances’ relative to the ESL (d = 1.78 [1.02-2.51]). Non-metric multidimensional scaling revealed clear multivariate competition dissimilarity, with ESL and NRL teams orienting distinctive positions on the ordination surface. Further, there was a greater spread in the relative positioning of NRL teams compared to ESL teams, indicating greater team dissimilarity within the NRL. Conclusions: Our observations may be explained by differing competition rule interpretations, in addition to differing game strategies and player skill capabilities. Both coaches and talent recruitment managers associated with these competitions may consider our data to assist with the identification and recruitment of suitable players from these respective competitions

Constructive role of non-adiabaticity for quantized charge pumping

We investigate a recently developed scheme for quantized charge pumping based on single-parameter modulation. The device was realized in an AlGaAl-GaAs gated nanowire. It has been shown theoretically that non-adiabaticity is fundamentally required to realize single-parameter pumping, while in previous multi-parameter pumping schemes it caused unwanted and less controllable currents. In this paper we demonstrate experimentally the constructive and destructive role of non-adiabaticity by analysing the pumping current over a broad frequency range.Comment: Presented at ICPS 2010, July 25 - 30, Seoul, Kore

Integrated quantized electronics: a semiconductor quantized voltage source

The Josephson effect in superconductors links a quantized output voltage Vout = f \cdot(h/2e) to the natural constants of the electron's charge e, Planck's constant h, and to an excitation frequency f with important applications in electrical quantum metrology. Also semiconductors are routinely applied in electrical quantum metrology making use of the quantum Hall effect. However, despite their broad range of further applications e.g. in integrated circuits, quantized voltage generation by a semiconductor device has never been obtained. Here we report a semiconductor quantized voltage source generating quantized voltages Vout = f\cdot(h/e). It is based on an integrated quantized circuit of a single electron pump operated at pumping frequency f and a quantum Hall device monolithically integrated in series. The output voltages of several \muV are expected to be scalable by orders of magnitude using present technology. The device might open a new route towards the closure of the quantum metrological triangle. Furthermore it represents a universal electrical quantum reference allowing to generate quantized values of the three most relevant electrical units of voltage, current, and resistance based on fundamental constants using a single device.Comment: 15 pages, 3 figure

Editorial: Rising stars in exercise physiology

[Extract] Physical exercise has been recognized as essential for human health and evolution for thousands of years, beginning with the ancient cultures. Hippocrates, Plato, Aristotle, and the Roman physician Galen were the earliest recorded and most well-known promoters of the beneficial effects of physical exercise. Since these times, several dedicated laboratories worldwide have been established, with many researchers conducting numerous investigations related to exercise physiology; nevertheless, a cornerstone of all laboratories is the development of new and novel researchers. These talented and emerging researchers have been necessary for our understanding of exercise physiology to have reached where we are today (and where we will be in the future). Given the evolution of exercise physiology, the field has incorporated a range of basic to applied scientific investigations and a range of end-users (e.g., researchers, athletes, coaches, physiologists, and clinical/public health professionals) who will benefit from these new advances in exercise physiology

An Artificially Lattice Mismatched Graphene/Metal Interface: Graphene/Ni/Ir(111)

We report the structural and electronic properties of an artificial graphene/Ni(111) system obtained by the intercalation of a monoatomic layer of Ni in graphene/Ir(111). Upon intercalation, Ni grows epitaxially on Ir(111), resulting in a lattice mismatched graphene/Ni system. By performing Scanning Tunneling Microscopy (STM) measurements and Density Functional Theory (DFT) calculations, we show that the intercalated Ni layer leads to a pronounced buckling of the graphene film. At the same time an enhanced interaction is measured by Angle-Resolved Photo-Emission Spectroscopy (ARPES), showing a clear transition from a nearly-undisturbed to a strongly-hybridized graphene $\pi$-band. A comparison of the intercalation-like graphene system with flat graphene on bulk Ni(111), and mildly corrugated graphene on Ir(111), allows to disentangle the two key properties which lead to the observed increased interaction, namely lattice matching and electronic interaction. Although the latter determines the strength of the hybridization, we find an important influence of the local carbon configuration resulting from the lattice mismatch.Comment: 9 pages, 3 figures, Accepted for publication in Phys. Rev.

Acute effects of traditional resistance training on sport-specific performance in adolescent cricket players

Cricket is a sport played internationally, which requires all players to partake in repetitive, high intensity bouts of exercise, to meet the anaerobic demands needed in a match. This can lead to cricket athletes undertaking resistance training to improve an aerobic performance. However, resistance training results in acute physiological stress known as exercise-induced muscle damage (EIMD), which has been reported to impair generic physical performance measures, subsequently impacting training practice and increasing injury susceptibility. The aim of this study was to examine the acute impact of EIMD on cricket bowling performance following traditional resistance training

Generation of energy selective excitations in quantum Hall edge states

We operate an on-demand source of single electrons in high perpendicular magnetic fields up to 30T, corresponding to a filling factor below 1/3. The device extracts and emits single charges at a tunable energy from and to a two-dimensional electron gas, brought into well defined integer and fractional quantum Hall (QH) states. It can therefore be used for sensitive electrical transport studies, e.g. of excitations and relaxation processes in QH edge states