Two placebo-controlled crossover studies in healthy subjects to evaluate gastric acid neutralization by an alginate–antacid formulation (Gaviscon Double Action)

Objective: To investigate the intragastric acid neutralization activity of a combined alginate-antacid formulation.

Significance: Published studies have investigated the reflux-suppressing alginate component of Gaviscon Double Action (Gaviscon DA; RB, UK) but intragastric acid neutralization activity of the antacid component has not been evaluated in vivo.

Methods: Intragastric pH monitoring, using a custom-made 10-electrode catheter, was evaluated in a two-part exploratory study in healthy subjects; Part I (n?=?6) tested suitability of the catheter using antacid tablets (Rennie; Bayer, Germany); Part II (n?=?12) evaluated gastric acid neutralization activity of Gaviscon DA liquid (20?ml) versus placebo in fasted subjects using a randomized, open-label, crossover design. The primary endpoint was the percentage of time that intragastric pH ≥4 was measured during 30?min post-treatment. A confirmatory study of identical design was subsequently conducted (n?=?20).

Results: Monitoring pH using the multielectrode catheter was a viable approach, directly detecting changes in intragastric pH following a single dose of antacid tablets. In the exploratory study, the percentage of time that pH ≥4 during 30?minutes post-treatment was 46.8% with Gaviscon DA liquid versus 4.7% with placebo (p?=?0.0004). These findings were supported by the confirmatory study, where pH ≥4 was recorded 50.8% of the time with Gaviscon DA versus 3.5% with placebo (p?=?0.0051). In this study, Gaviscon DA was safe and well tolerated.

Conclusions: These studies demonstrate the effective acid neutralizing capacity of Gaviscon DA versus placebo in healthy, fasted subjects. This adds to the evidence base for the combination of alginates and antacids.     

ALLSTEPS: Curriculum-driven Learning of Stepping Stone Skills

Humans are highly adept at walking in environments with foot placement constraints, including stepping-stone scenarios where footstep locations are fully constrained. Finding good solutions to stepping-stone locomotion is a longstanding and fundamental challenge for animation and robotics. We present fully learned solutions to this difficult problem using reinforcement learning. We demonstrate the importance of a curriculum for efficient learning and evaluate four possible curriculum choices compared to a non-curriculum baseline. Results are presented for a simulated humanoid, a realistic bipedal robot simulation and a monster character, in each case producing robust, plausible motions for challenging stepping stone sequences and terrains.     

A review of salt marsh dynamics

Salt marshes have been the subject of extensive research over many years. As well as gaining the interest of biologists, physical processes within the marsh have been measured in some detail since at least the 1920s. There have been various attempts to develop a fuller understanding of the inter‐relationship between physical and biological processes within salt marshes. Advances often go in step changes. Over the last 10–20 years, there has been such a change with the ability to capture and manipulate spatial data in sufficient detail to be able to resolve not only surface topography but also variations in vegetation and a number of relevant physical properties. This review paper seeks to highlight the advances in the understanding of salt marsh dynamics and our ability to investigate the relationships between physical and biological properties. Some consideration is also given to the areas that would benefit from new or further research.     

Systematic mesh development for 3D CFD simulation of fixed beds: Single sphere study

To develop and validate meshes for computational fluid dynamics (CFD) simulations of transport in fixed beds, a single particle is often used as a test case. We present results for drag coefficient (C_D) and heat transfer Nusselt number (Nu) for flow past a sphere, focusing on high flow rates typical of industrial steam reformers (400 < Re < 20,000). Over this range, good predictions of C_D were obtained using large eddy simulation (LES) to capture vortex shedding and wake dynamics, with a mesh refined downstream from the sphere. The small time-steps and high cell count required make this too expensive for fixed beds. Nu can be accurately calculated using a Reynolds-averaged Navier-Stokes (RANS) method with shear-stress transport (SST) k-ω closure provided the mesh at the particle surface is fine enough and covers most of the boundary layer. Single sphere simulations of heat transfer are more useful for fixed bed mesh development than drag coefficient calculations.     

Social cost-benefit analysis of electricity interconnector investment: A critical appraisal

This paper examines the economic analysis (social cost-benefit analysis) underlying two decisions to build an interconnector (NorNed and the East–West interconnector) in Europe. The main conclusion is that current interconnector and transmission investment decisions in Europe are unlikely to maximize social welfare. The arguments are as follows. (i) It is unclear how much demand for transmission capacity and interconnectors actually exists, and thus the benefits of investment are unclear. (ii) Both analyses underlying the investments studied are incorrect, to the point where, in one case, even the sign may be wrong. (iii) The main criticism concerns the fact that they do not take the resulting changes in generator investment plans into account and ignore the (potential) benefits of increased competition. (iv) Several smaller issues can be improved, such as the discount rate used. (v) Decisions at the European level are taken very differently, and approval may depend on which authority grants approval. (vi) Interconnector decisions receive the most attention, although most money goes to transmission investments. Two research recommendations for future improvements are formulated.     

Comparison of high impedance input topologies with low EMI susceptibility

Different Input Topologies with resistance to electromagnetic interferences (EMI) are analyzed and compared in terms of EMI reduction. The emphasis in this study is put on circuit robustness and applicability to industrial applications, which requires sufficient EMI rejection over all process corners. Furthermore, a new topology based on a replica amplifier is introduced, that is more robust to process variation compared to previous works (Jean-Michel Redouté and Michiel Steyaert, ESSCIRC, Sept. 2008; Fiori, IEEE Transac Electromag Compat 49(4):834–839, 2007) that rely on accurate matching of absolute values in order to achieve efficient EMI cancellation.