Percutaneous gastrostomy: troubleshooting complications

Percutaneous endoscopic gastrostomy was first described in 1980 (Gauderer et al, 1980), superseding surgical gastrostomy as a means of providing long-term enteral nutrition. Despite the commonality of this procedure, its associated morbidity and mortality rates are significant, with directly attributable rates of 1:30 and 1:150 respectively. Poor patient selection and poor management are the principal factors contributing to adverse outcomes. The 2004 National Confidential Enquiry into Patient Outcome and Death recorded that 19% of percutaneous endoscopic gastrostomy procedures performed were ‘futile or not indicated at all’. This article provides a practical approach to avoiding and treating complications associated with percutaneous endoscopic gastrostomy feeding

Alcohol Intake and Blood Pressure: A Systematic Review Implementing a Mendelian Randomization Approach

Using a mendelian randomization approach Sarah Lewis and colleagues find strong support for the hypothesis that alcohol intake has a marked effect on blood pressure and the risk of hypertension

On the Enforcement of Trade Embargoes by the Merchant Guilds

Compensation from rulers of trading centres to merchants whose property rights had been violated was a notable feature of early European international trade. We demonstrate in a repeated-game model that demands for compensation made threats by merchant guilds to impose trade boycotts self-enforcing for individual merchants, thus removing incentives for embargo breaking that could otherwise have rendered guilds powerless. Long-distance merchants were thus protected from predation by medieval city rulers, possibly providing a foundation for the trade expansion of the `Commercial Revolution'. We also address the frequently neglected issue of whether the guilds and cities would have agreed on the level of trade which they wished to support

On the Enforcement of Trade Embargoes by the Merchant Guilds

Compensation from rulers of trading centres to merchants whose property rights had been violated was a notable feature of early European international trade. We demonstrate in a repeated-game model that demands for compensation made threats by merchant guilds to impose trade boycotts self-enforcing for individual merchants, thus removing incentives for embargo breaking that could otherwise have rendered guilds powerless. Long-distance merchants were thus protected from predation by medieval city rulers, possibly providing a foundation for the trade expansion of the `Commercial Revolution'. We also address the frequently neglected issue of whether the guilds and cities would have agreed on the level of trade which they wished to support

Charged quantum dot micropillar system for deterministic light-matter interactions

This work was funded by the Future Emerging Technologies (FET) programme within the Seventh Framework Programme for Research of the European Commission, FET-Open, FP7-284743 [project Spin Photon Angular Momentum Transfer for Quantum Enabled Technologies (SPANGL4Q)] and the German Ministry of Education and research (BMBF) and Engineering and Physical Sciences Research Council (EPSRC) [project Solid State Quantum Networks (SSQN)]. J.G.R. is sponsored by the EPSRC fellowship EP/M024458/1.Quantum dots (QDs) are semiconductor nanostructures in which a three-dimensional potential trap produces an electronic quantum confinement, thus mimicking the behavior of single atomic dipole-like transitions. However, unlike atoms, QDs can be incorporated into solid-state photonic devices such as cavities or waveguides that enhance the light-matter interaction. A near unit efficiency light-matter interaction is essential for deterministic, scalable quantum-information (QI) devices. In this limit, a single photon input into the device will undergo a large rotation of the polarization of the light field due to the strong interaction with the QD. In this paper we measure a macroscopic (∼6∘) phase shift of light as a result of the interaction with a negatively charged QD coupled to a low-quality-factor (Q∼290) pillar microcavity. This unexpectedly large rotation angle demonstrates that this simple low-Q-factor design would enable near-deterministic light-matter interactions.Publisher PDFPeer reviewe

Synovial changes detected by ultrasound in people with knee osteoarthritis - a meta-analysis of observational studies

Objectives To examine the prevalence of synovial effusion, synovial hypertrophy and positive Doppler signal (DS) detected by ultrasound (US) in people with knee osteoarthritis (OA) and/or knee pain compared to that in the general population. Method A systematic literature search was undertaken in Medline, EMBASE, Allied and Complementary Medicine, PubMed Web of Science, and SCOPUS databases in May 2015. Frequencies of US abnormalities in people with knee OA/pain, in the general population or asymptomatic controls were pooled using the random effects model. Publication bias and heterogeneity between studies were examined. Results Twenty four studies in people with knee pain/OA and five studies of the general population or asymptomatic controls met the inclusion criteria. The pooled prevalence of US effusion, synovial hypertrophy and positive DS in people with knee OA/pain were 51.5% (95% CI 40.2 to 62.8), 41.5% (26.3–57.5) and 32.7% (8.34–63.24), respectively, which were higher than those in the general population or asymptomatic controls (19.9% (95%CI 7.8–35.3%), 14.5% (0–58.81), and 15.8 (3.08–35.36), respectively). People with knee OA (ACR criteria or radiographic OA) had greater prevalence of US abnormalities than people with knee pain (P = 0.037, P = 0.010 and P = 0.009, respectively). Conclusions US detected effusion, synovial hypertrophy and DS are more common in people with knee OA/pain, compared to the general population. These abnormalities relate more to presence of OA structural changes than to pain

Quantum modulation of a coherent state wavepacket with a single electron spin

The interaction of quantum objects lies at the heart of fundamental quantum physics and is key to a wide range of quantum information technologies. Photon-quantum-emitter interactions are among the most widely studied. Two-qubit interactions are generally simplified into two quantum objects in static well-defined states . In this work we explore a fundamentally new dynamic type of spin-photon interaction. We demonstrate modulation of a coherent narrowband wavepacket with another truly quantum object, a quantum dot with ground state spin degree of freedom. What results is a quantum modulation of the wavepacket phase (either 0 or {\pi} but no values in between), a new quantum state of light that cannot be described classically.Comment: Supplementary Information available on reques

Efficient Quantum Photonic Phase Shift in a Low Q-Factor Regime

This work was funded by the Future Emerging Technologies (FET)-Open FP7-284743 [project Spin Photon Angular Momentum Transfer for Quantum Enabled Technologies (SPANGL4Q)] and the German Ministry of Education and research (BMBF) and Engineering and Physical Sciences Research Council (EPSRC) (EP/M024156/1, EP/N003381/1 and EP/M024458/1). J.J.H. was supported by the Bristol Quantum Engineering Centre for Doctoral Training, EPSRC grant EP/L015730/1. We acknowledge the GW4 network for funding of A.Y.Solid-state quantum emitters have long been recognised as the ideal platform to realize integrated quantum photonic technologies. We demonstrate that a self-assembled negatively charged quantum dot (QD) in a low Q-factor photonic micropillar is a suitable design for deterministic polarisation switching and spin-photon entanglement. We show this by measuring a shift in phase of an input single photon of at least 2π/3. As we explain in the text, this is strong experimental proof that input photons can interact with the emitter deterministically. A deterministic photon-emitter interaction is a viable and scalable means to achieve several vital functionalities such as single photon switches and entanglement gates. Our experimentally determined value is limited by mode mismatch between the input laser and the cavity, QD spectral fluctuations and spin relaxation. When on-resonance we estimate that up to ∼80% of the collected photons couple into the cavity mode and have interacted with the QD and undergone a phase shift of π.PostprintPeer reviewe

Near-threshold high spin amplification in a 1300 nm GaInNAs spin laser

Using continuous-wave optical pumping of a spin-VCSEL at room temperature, we find high spin amplification of the pump close to threshold within the communications wavelength window, here at 1300 nm. This facilitates a strong switch from left to right circularly polarised light emission, which has potential applications in polarisation encoding for data communications. We use a simple spin flip model to fit the experimental results and discuss the VCSEL parameters that affect this amplification