Pseudotyping exosomes for enhanced protein delivery in mammalian cells.

Exosomes are cell-derived nanovesicles that hold promise as living vehicles for intracellular delivery of therapeutics to mammalian cells. This potential, however, is undermined by the lack of effective methods to load exosomes with therapeutic proteins and to facilitate their uptake by target cells. Here, we demonstrate how a vesicular stomatitis virus glycoprotein (VSVG) can both load protein cargo onto exosomes and increase their delivery ability via a pseudotyping mechanism. By fusing a set of fluorescent and luminescent reporters with VSVG, we show the successful targeting and incorporation of VSVG fusions into exosomes by gene transfection and fluorescence tracking. We subsequently validate our system by live cell imaging of VSVG and its participation in endosomes/exosomes that are ultimately released from transfected HEK293 cells. We show that VSVG pseudotyping of exosomes does not affect the size or distributions of the exosomes, and both the full-length VSVG and the VSVG without the ectodomain are shown to integrate into the exosomal membrane, suggesting that the ectodomain is not required for protein loading. Finally, exosomes pseudotyped with full-length VSVG are internalized by multiple-recipient cell types to a greater degree compared to exosomes loaded with VSVG without the ectodomain, confirming a role of the ectodomain in cell tropism. In summary, our work introduces a new genetically encoded pseudotyping platform to load and enhance the intracellular delivery of therapeutic proteins via exosome-based vehicles to target cells

The Non-Homologous Nature of Solar Diameter Variations

We show in this paper that the changes of the solar diameter in response to variations of large scale magnetic fields and turbulence are not homologous. For the best current model, the variation at the photospheric level is over 1000 times larger than the variation at a depth of 5 Mm, which is about the level at which f-mode solar oscillations determine diameter variations. This model is supported by observations that indicate larger diameter changes for high degree f-modes than for low degree f-modes, since energy of the former are concentrated at shallower layers than the latter.Comment: 11 pages, 3 figures, aastex style, accepted for publication by ApJ

Lay epidemiology and the interpretation of low-risk drinking guidelines by adults in the United Kingdom

Aims To explore how the concept of lay epidemiology can enhance understandings of how drinkers make sense of current UK drinking guidelines. Methods Qualitative study using 12 focus groups in four sites in northern England and four sites in central Scotland. Participants were 66 male and female drinkers, aged between 19 and 65 years, of different socio-economic backgrounds. Data were analysed thematically using a conceptual framework of lay epidemiology. Results Current drinking guidelines were perceived as having little relevance to participants' drinking behaviours and were generally disregarded. Daily guidelines were seen as irrelevant by drinkers whose drinking patterns comprised heavy weekend drinking. The amounts given in the guidelines were seen as unrealistic for those motivated to drink for intoxication, and participants measured alcohol intake in numbers of drinks or containers rather than units. Participants reported moderating their drinking, but this was out of a desire to fulfil work and family responsibilities, rather than concerns for their own health. The current Australian and Canadian guidelines were preferred to UK guidelines, as they were seen to address many of the above problems. Conclusions Drinking guidelines derived from, and framed within, solely epidemiological paradigms lack relevance for adult drinkers who monitor and moderate their alcohol intake according to their own knowledge and risk perceptions derived primarily from experience. Insights from lay epidemiology into how drinkers regulate and monitor their drinking should be used in the construction of drinking guidelines to enhance their credibility and efficacy

Avoiding the bullwhip effect using Damped Trend forecasting and the Order-Up-To replenishment policy

We study the Damped Trend forecasting method and its bullwhip generating behaviour when used within the Order-Up-To (OUT) replenishment policy. Using z-transform transfer functions we determine complete stability criteria for the Damped Trend forecasting method. We show that this forecasting mechanism is stable for a much larger proportion of the parametrical space than is generally acknowledged in the literature. We provide a new proof to the known fact that the Naïve, Exponential Smoothing and Holts Method forecasting, when used inside the OUT policy, will always generate bullwhip for every possible demand process, for any lead-time. Further, we demonstrate the Damped Trend OUT system behaves differently. Sometimes it will generate bullwhip and sometimes it will not. Bullwhip avoidance occurs when demand is dominated by low frequency harmonics in some instances. In other instances bullwhip avoidance happens when demand is dominated by high frequency harmonics. We derive sufficient conditions for when bullwhip will definitely be generated and necessary conditions for when bullwhip may be avoided. We verify our analytical findings with a numerical investigation

Extended Ordered Paired Comparison Models with Application to Football Data from German Bundesliga

A general paired comparison model for the evaluation of sports competitions is proposed. It efficiently uses the available information by allowing for ordered response categories and team-specific home advantage effects. Penalized estimation techniques are used to identify clusters of teams that share the same ability. The model is extended to include team-specific explanatory variables. It is shown that regularization techniques allow to identify the contribution of explanatory variables to the success of teams. The usefulness of the methods is demonstrated by investigating the performance and its dependence on the budget for football teams of the German Bundesliga