German crowd-investing platforms: Literature review and survey

This article presents a comprehensive overview of the current German crowd-investing market drawing on a data-set of 31 crowd-investing platforms including the analysis of 265 completed projects. While crowd-investing market still only represents a niche in the German venture capital market, there is potential for an increase in both market volume and in average project investment. The market share is distributed among a few crowd-investing platforms with high entry barriers for new platforms although platforms that specialise in certain sectors have managed to successfully enter the market. German crowd-investing platforms are found to promote mainly internet-based enterprises (36%) followed by projects in real estate (24%) and green projects (19%), with the median money raised 100,000 euro

Purinergic receptor mediated calcium signalling in urothelial cells

Non-neuronal ATP released from the urothelium in response to bladder stretch is a key modulator of bladder mechanosensation. Whilst non-neuronal ATP acts on the underlying bladder afferent nerves to facilitate sensation, there is also the potential for ATP to act in an autocrine manner, modulating urothelial cell function. The aim of this study was to systematically characterise the functional response of primary mouse urothelial cells (PMUCs) to ATP. PMUCs isolated from male mice (14-16 weeks) were used for live-cell fluorescent calcium imaging and qRT-PCR to determine the expression profile of P2X and P2Y receptors. The majority of PMUCs (74-92%) responded to ATP (1 μM-1 mM), as indicted by an increase in intracellular calcium (iCa2+). PMUCs exhibited dose-dependent responses to ATP (10 nM-1 mM) in both calcium containing (2 mM, EC50 = 3.49 ± 0.77 μM) or calcium free (0 mM, EC50 = 9.5 ± 1.5 μM) buffers. However, maximum iCa2+ responses to ATP were significantly attenuated upon repetitive applications in calcium containing but not in calcium free buffer. qRT-PCR revealed expression of P2X1-6, and P2Y1-2, P2Y4, P2Y6, P2Y11-14, but not P2X7 in PMUCs. These findings suggest the major component of ATP induced increases in iCa2+ are mediated via the liberation of calcium from intracellular stores, implicating functional P2Y receptors that are ubiquitously expressed on PMUCs.Russell Chess-Williams, Donna J. Sellers, Stuart M. Brierley, David Grundy, Luke Grund

An empirical investigation into the drivers of re-subscription in massively multiplayer online games: a commitment trust theory approach

This is a relationship marketing PhD which is examining, using Commitment Trust Theory, the customer decision to maintain subscribing to a massively multiplayer online game. This PhD is not an examination of initial purchase decision, but of the ongoing, post-purchase, customer retention. In keeping with the contextual nature of Commitment Trust Theory, this study examines the antecedents of the re-subscription decision and their effect on the key mediating variables of Commitment and Trust and modifies the framework to model the subscription based nature of the business situation and the context. The key contribution of this research to the literature is the application of the Commitment Trust framework to a customer’s ongoing relationship with a massively multiplayer online game entertainment product; a situation and context which has not been examined in the literature. An online questionnaire survey was used to collect a sample of data from 2226 massively multiplayer online game customers. This sample data was then analysed using Structural Equation Modelling to test the relationship hypotheses between the constructs proposed by Commitment Trust Theory. Furthermore, hypotheses examining the effect of relevant demographic and categorical variables upon the constructs of Commitment Trust Theory were also tested and analysed using appropriate statistical techniques. Evidence was found to support the Commitment Trust Theory framework in a massively multiplayer online game subscription situation, with the study’s model explaining 85.7% of the variance of the sample data, with evidence presented to support the key mediating variable approach to modelling the circumstances. The study, based on examining the effect size of the construct relationships using standardised regression weights then gives evidence that a more parsimonious model which reduces the number of constructs from 16 to six (a 70% reduction in complexity) would still produce a model explaining 85.3% of the variance of the sample data (a 0.4% loss in explanatory power). The study concludes that the key antecedent constructs in the sample for a customer’s renewal of an online gaming subscription are current satisfaction, past satisfaction, the amount of game capital they have within the game and the metagame benefits they derive from the game. The study supports a key mediating variable structure, but provides evidence that while Commitment and Trust are both relevant and statistically significant, a more efficient explanation examining the effect size of the relationships as well, would focus on the antecedents of Commitment rather than Trust, as Trust and its antecedents were not found to have a significant effect size on the overall decision to re-subscribe

Liver Transplantation to Provide Low-Density-Lipoprotein Receptors and Lower Plasma Cholesterol in a Child with Homozygous Familial Hypercholesterolemia

A six-year-old girl with severe hypercholesterolemia and atherosclerosis had two defective genes at the low-density-lipoprotein (LDL) receptor locus, as determined by biochemical studies of cultured fibroblasts. One gene, inherited from the mother, produced no LDL receptors; the other gene, inherited from the father, produced a receptor precursor that was not transported to the cell surface and was unable to bind LDL. The patient degraded intravenously administered 125I-LDL at an extremely low rate, indicating that her high plasma LDL-cholesterol level was caused by defective receptor-mediated removal of LDL from plasma. After transplantation of a liver and a heart from a normal donor, the patient's plasma LDL-cholesterol level declined by 81 per cent, from 988 to 184 mg per deciliter. The fractional catabolic rate for intravenously administered 125I-LDL, a measure of functional LDL receptors in vivo, increased by 2.5-fold. Thus, the transplanted liver, with its normal complement of LDL receptors, was able to remove LDL cholesterol from plasma at a nearly normal rate. We conclude that a genetically determined deficiency of LDL receptors can be largely reversed by liver transplantation. These data underscore the importance of hepatic LDL receptors in controlling the plasma level of LDL cholesterol in human beings. (N Engl J Med 1984; 311: 1658–64.). © 1984, Massachusetts Medical Society. All rights reserved