Simulation Study of a Gramicidin/Lipid Bilayer System in Excess Water and Lipid. II. Rates and Mechanisms of Water Transport

AbstractA gramicidin channel in a fluid phase DMPC bilayer with excess lipid and water has been simulated. By use of the formal correspondence between diffusion and random walk, a permeability for water through the channel was calculated, and was found to agree closely with the experimental results of Rosenberg and Finkelstein (Rosenberg, P. A., and A. Finkelstein. 1978. J. Gen. Physiol. 72:327–340; 341–350) for permeation of water through gramicidin in a phospholipid membrane. By using fluctuation analysis, components of resistance to permeation were computed for movement through the channel interior, for the transition step at the channel mouth where the water molecule solvation environment changes, and for the process of diffusion up to the channel mouth. The majority of the resistance to permeation appears to occur in the transition step at the channel mouth. A significant amount is also due to structurally based free energy barriers within the channel. Only small amounts are due to local friction within the channel or to diffusive resistance for approaching the channel mouth

Impact of Social Media Management Styles on Willingness to Be a Fan: A Transaction Cost Economics Perspective

This study investigates the impacts of different styles of social media management on user’s willingness to be a fan. Six companies’ brand-pages on a social media site are examined. Data are collected using survey and interview with a group of social media users. Qualitative data analyses are conducted based on 30 observation reports and 60 open-ended surveys, with follow-up interviews. Grounded on the theoretical lens of transaction cost economics, we find that companies successful in attracting more fans adopt the bilateral governance structure (with frequent updates and mixed asset specificity) in their social media transactions. They are relatively more dedicated and allocate more amounts of resources in their social media interactions. Practicing the right governance structure is demonstrated to be more preferable to the fans, able to attract more engagement and generate organic media in the long run. This is because it is helpful for creating positive perceptions of a brand-page, and fans find it useful in reducing their efforts in information searching and product procurement and social networking costs; and this in turn shows to positively impact one’s willingness to be a fan of the page, which can possibly create the opportunities to be a potential customer, leading to future purchases from the brand. This study also identifies the key concepts or sub-constructs of (user’s) willingness to be a fan of a brand-page in the context of social media. They are brand-page management style (dedicated, caring, responsive), contents (quality, usefulness, diversity) and product (uniqueness, variety, popularity). Available at: https://aisel.aisnet.org/pajais/vol11/iss2/2

Reframing Kurtz’s Painting: Colonial Legacies and Minority Rights in Ethnically Divided Societies

Minority rights constitute some of the most normatively and economically important human rights. Although the political science and legal literatures have proffered a number of constitutional and institutional design solutions to address the protection of minority rights, these solutions are characterized by a noticeable neglect of, and lack of sensitivity to, historical processes. This Article addresses that gap in the literature by developing a causal argument that explains diverging practices of minority rights protections as functions of colonial governments’ variegated institutional practices with respect to particular ethnic groups. Specifically, this Article argues that in instances where colonial governments politicize and institutionalize ethnic hegemony in the pre-independence period, an institutional legacy is created that leads to lower levels of minority rights protections. Conversely, a uniform treatment and depoliticization of ethnicity prior to independence ultimately minimizes ethnic cleavages post-independence and consequently causes higher levels of minority rights protections. Through a highly structured comparative historical analysis of Botswana and Ghana, this Article builds on a new and exciting research agenda that focuses on the role of long-term historio-structural and institutional influences on human rights performance and makes important empirical contributions by eschewing traditional methodologies that focus on single case studies that are largely descriptive in their analyses. Ultimately, this Article highlights both the strength of a historical approach to understanding current variations in minority rights protections and the varied institutional responses within a specific colonial government

An Exploratory Study on the Impact of Trust on Different E-Payment Gateways: Octopus Card Vs. Credit Card

The study of trust of consumer on Business-to-Consumer (B2C) E-commerce is one of the key research interests of Information Systems (IS) researchers. In this research, we investigate the impact of trust on two different E-payment gateways, viz. online credit card payment system and the hypothetical online Octopus card (a stored-value smart card) payment system. Based on the model developed by Gefen et al. (2003) and McKnight et al. (2002a), we synthesize our own research model by incorporating disposition to trust, and trust and its antecedents with the Technology Acceptance Model (TAM). An online survey was conducted on the Government-to-Citizen (G2C) E-commerce portal of the Hong Kong Government and 2,481 usable responses were collected. The empirical result shows that consumers in Hong Kong are using different trust building processes to consider their adoption for E-payment gateways

Improving predicted protein loop structure ranking using a Pareto-optimality consensus method

<p>Abstract</p> <p>Background</p> <p>Accurate protein loop structure models are important to understand functions of many proteins. Identifying the native or near-native models by distinguishing them from the misfolded ones is a critical step in protein loop structure prediction.</p> <p>Results</p> <p>We have developed a Pareto Optimal Consensus (POC) method, which is a consensus model ranking approach to integrate multiple knowledge- or physics-based scoring functions. The procedure of identifying the models of best quality in a model set includes: 1) identifying the models at the Pareto optimal front with respect to a set of scoring functions, and 2) ranking them based on the fuzzy dominance relationship to the rest of the models. We apply the POC method to a large number of decoy sets for loops of 4- to 12-residue in length using a functional space composed of several carefully-selected scoring functions: Rosetta, DOPE, DDFIRE, OPLS-AA, and a triplet backbone dihedral potential developed in our lab. Our computational results show that the sets of Pareto-optimal decoys, which are typically composed of ~20% or less of the overall decoys in a set, have a good coverage of the best or near-best decoys in more than 99% of the loop targets. Compared to the individual scoring function yielding best selection accuracy in the decoy sets, the POC method yields 23%, 37%, and 64% less false positives in distinguishing the native conformation, indentifying a near-native model (RMSD < 0.5A from the native) as top-ranked, and selecting at least one near-native model in the top-5-ranked models, respectively. Similar effectiveness of the POC method is also found in the decoy sets from membrane protein loops. Furthermore, the POC method outperforms the other popularly-used consensus strategies in model ranking, such as rank-by-number, rank-by-rank, rank-by-vote, and regression-based methods.</p> <p>Conclusions</p> <p>By integrating multiple knowledge- and physics-based scoring functions based on Pareto optimality and fuzzy dominance, the POC method is effective in distinguishing the best loop models from the other ones within a loop model set.</p

The Impacts of Information Privacy, Monetary Reward, and Buyers’ Protection Excess on Consumers’ Utility Using E-payment Gateways: A Conjoint Analysis

This paper reports our findings on the impacts of information privacy, financial reward, and buyers’ protection excess on consumers’ utility using E-payment Gateways. We invited users of the G2C E-government Portal of Hong Kong to participate in an online experiment and collected data from 1,795 subjects. From our conjoint analysis, we find that monetary reward has the most significant impact on consumers’ utility among the six design attributes of E-payment Gateways investigated in this study, i.e. monetary reward, online transfer of information, acceptability, buyers’ protection excess, anonymity, and physical control. We also observe that there is a gender impact on the relative importance of these attributes