SciCombinator

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Concept: Exchange

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Online traces of human activity offer novel opportunities to study the dynamics of complex knowledge exchange networks, in particular how emergent patterns of collective attention determine what new information is generated and consumed. Can we measure the relationship between demand and supply for new information about a topic? We propose a normalization method to compare attention bursts statistics across topics with heterogeneous distribution of attention. Through analysis of a massive dataset on traffic to Wikipedia, we find that the production of new knowledge is associated to significant shifts of collective attention, which we take as proxy for its demand. This is consistent with a scenario in which allocation of attention toward a topic stimulates the demand for information about it, and in turn the supply of further novel information. However, attention spikes only for a limited time span, during which new content has higher chances of receiving traffic, compared to content created later or earlier on. Our attempt to quantify demand and supply of information, and our finding about their temporal ordering, may lead to the development of the fundamental laws of the attention economy, and to a better understanding of social exchange of knowledge information networks.

Concepts: Attention economy, Data, Information, Knowledge, Supply and demand, Measure, Knowledge management, Exchange

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The re-use of previously validated designs is critical to the evolution of synthetic biology from a research discipline to an engineering practice. Here we describe the Synthetic Biology Open Language (SBOL), a proposed data standard for exchanging designs within the synthetic biology community. SBOL represents synthetic biology designs in a community-driven, formalized format for exchange between software tools, research groups and commercial service providers. The SBOL Developers Group has implemented SBOL as an XML/RDF serialization and provides software libraries and specification documentation to help developers implement SBOL in their own software. We describe early successes, including a demonstration of the utility of SBOL for information exchange between several different software tools and repositories from both academic and industrial partners. As a community-driven standard, SBOL will be updated as synthetic biology evolves to provide specific capabilities for different aspects of the synthetic biology workflow.

Concepts: Natural selection, Evolution, Species, Computer program, Implementation, Design, Community, Exchange

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Abstract This study employs the perspective of social exchange theory and seeks to understand users' intentions to use social recommender systems (SRS) through three psychological factors: trust, shared values, and reputation. We use structural equation modeling to analyze 221 valid questionnaires. The results show that trust has a direct positive influence on the intention to use SRS, followed by shared values, whereas reputation has an indirect influence on SRS use. We further discuss specific recommendations concerning these factors for developing SRS.

Concepts: Sociology, Value, Social psychology, Reputation management, Exchange, Social exchange theory, Recommender system

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Now that glitch-free U.S. health insurance exchanges are presenting consumers with robust sets of health insurance choices, it’s time to redesign exchange websites so as to maximize the chances that consumers will choose plans best suited to their needs and preferences.

Concepts: Health economics, Economics, Business, Microeconomics, Exchange

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Permanency of mechanosensory stereocilia may be the consequence of low protein turnover or rapid protein renewal. Here, we devise a system, using optical techniques in live zebrafish, to distinguish between these mechanisms. We demonstrate that the stereocilium’s abundant actin cross-linker fascin 2b exchanges, without bias or a phosphointermediate, orders of magnitude faster (t1/2 of 76.3 s) than any other known hair bundle protein. To establish the logic of fascin 2b’s exchange, we examine whether filamentous actin is dynamic and detect substantial β-actin exchange within the stereocilium’s paracrystal (t1/2 of 4.08 hr). We propose that fascin 2b’s behavior may enable cross-linking at fast timescales of stereocilia vibration while noninstructively facilitating the slower process of actin exchange. Furthermore, tip protein myosin XVa fully exchanges in hours (t1/2 of 11.6 hr), indicating that delivery of myosin-associated cargo occurs in mature stereocilia. These findings suggest that stereocilia permanency is underpinned by vibrant protein exchange.

Concepts: Proteins, Protein, Actin, Myosin, Cytoskeleton, Motor protein, Cross-link, Exchange

16

In the wild, primates are selective over the routes that they take when foraging and seek out preferred or ephemeral food. Given this, we tested how a group of captive chimpanzees weighed the relative benefits and costs of foraging for food in their environment when a less-preferred food could be obtained with less effort than a more-preferred food. In this study, a social group of six zoo-housed chimpanzees (Pan troglodytes) could collect PVC tokens and exchange them with researchers for food rewards at one of two locations. Food preference tests had revealed that, for these chimpanzees, grapes were a highly-preferred food while carrot pieces were a less-preferred food. The chimpanzees were tested in three phases, each comprised of 30 thirty-minute sessions. In phases 1 and 3, if the chimpanzees exchanged a token at the location they collected them they received a carrot piece (no travel) or they could travel ≥10 m to exchange tokens for grapes at a second location. In phase 2, the chimpanzees had to travel for both rewards (≥10 m for carrot pieces, ≥15 m for grapes). The chimpanzees learned how to exchange tokens for food rewards, but there was individual variation in the time it took for them to make their first exchange and to discover the different exchange locations. Once all the chimpanzees were proficient at exchanging tokens, they exchanged more tokens for grapes (phase 3). However, when travel was required for both rewards (phase 2), the chimpanzees were less likely to work for either reward. Aside from the alpha male, all chimpanzees exchanged tokens for both reward types, demonstrating their ability to explore the available options. Contrary to our predictions, low-ranked individuals made more exchanges than high-ranked individuals, most likely because, in this protocol, chimpanzees could not monopolize the tokens or access to exchange locations. Although the chimpanzees showed a preference for exchanging tokens for their more-preferred food, they appeared to develop strategies to reduce the cost associated with obtaining the grapes, including scrounging rewards and tokens from group mates and carrying more than one token when travelling to the farther exchange location. By testing the chimpanzees in their social group we were able to tease apart the social and individual influences on their decision making and the interplay with the physical demands of the task, which revealed that the chimpanzees were willing to travel farther for better.

Concepts: Exchange, Microsoft Exchange Server

8

Beginning in 2014, federal guidelines for health plans sold to people in the individual market allow insurers to charge tobacco users up to 50 percent more for premiums, compared to nonusers. We examined variations in tobacco surcharges for plans offered through the state and federal health insurance exchanges, or Marketplaces. The plan with the median surcharge had only 10 percent higher premiums for tobacco users compared to nonusers, and nine in ten plans charged a lower surcharge than allowed. Even with such lower-than-allowed surcharges, tobacco users lacked affordable coverage-defined as access to at least one plan with premiums of less than 8 percent of income after subsidies-in more states than did nonusers. Higher premiums could encourage tobacco users to opt out of coverage. Our results also suggest that the variation in tobacco surcharges may result in the sorting of tobacco users and nonusers into different plans.

Concepts: Management, Insurance, State, Plan, Market, Exchange, Surcharge

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We examined whether and why range offers (e.g., “I want $7,200 to $7,600 for my car”) matter in negotiations. A selective-attention account predicts that motivated and skeptical offer-recipients focus overwhelmingly on the attractive endpoint (i.e., a buyer would hear, in effect, “I want $7,200”). In contrast, we propose a tandem anchoring account, arguing that offer-recipients are often influenced by both endpoints as they judge the offer-maker’s reservation price (i.e., bottom line) as well as how polite they believe an extreme (nonaccommodating) counteroffer would be. In 5 studies, featuring scripted negotiation scenarios and live dyadic negotiations, we find that certain range offers yield improved settlement terms for offer-makers without relational costs, whereas others may yield relationship benefits without deal costs. We clarify the types of range offers that evoke these benefits and identify boundaries to their impact, including range width and extremity. In addition, our studies reveal evidence consistent with 2 proposed mechanisms, one involving an informational effect (both endpoints of range offers can be taken as signals of an offer-maker’s reservation price) and another involving a politeness effect (range offers can make extreme counteroffers seem less polite). Our results have implications for models of negotiation behavior and outcomes and, more broadly, for the nature of social exchange. (PsycINFO Database Record © 2015 APA, all rights reserved).

Concepts: Proposal, All rights reserved, American Psychological Association, Copyright, Relational database, Negotiation, Exchange, Politeness

4

The presence of sex disparity in living donor kidney transplantation (LDKT) remains controversial. To determine if women fall behind men in LDKT evaluation, we performed an intention to treat study of 2587 candidates listed for kidney transplant at a single transplant center over 7 years. We found that women and men kidney transplant candidates engaged an equivalent type and number of prospective living donors. However, sex-specific differences in sensitization history and histocompatibility reduced the rate of LDKT for women by 30%. Pregnancy-induced incompatibility with spouse donors was limiting given that spouses were among the individuals most likely to complete donation. Notably, participation in a kidney paired exchange program eliminated sex-based differences in LDKT. Collectively, these data suggest that pregnancy is a formidable biologic barrier for women and contributes uniquely to sex disparity in LDKT. Targeted efforts to improve transplant center participation in paired kidney exchanges may increase sex equity in LDKT.

Concepts: Chronic kidney disease, Kidney, Nephrology, Diabetic nephropathy, Organ transplant, Kidney transplantation, Organ donation, Exchange

3

Electronic health information exchange can improve care coordination for patients by enabling more timely and complete sharing of clinical information among providers and hospitals. Approaches to health information exchange have expanded in recent years with the growth in entities such as regional health information organizations (HIOs) and the increased adoption of electronic health record (EHR) systems. However, little is known about the extent of exchange activity in US hospitals. Using national surveys of hospitals, we found that between 2008 and 2012, hospitals' electronic exchange of health information with other providers increased significantly, regardless of provider type, organizational affiliation, or type of clinical information. In 2012 nearly six in ten hospitals actively exchanged electronic health information with providers and hospitals outside their organization, an increase of 41 percent since 2008. EHR adoption and HIO participation were associated with significantly greater hospital exchange activity, but exchanges with providers outside the organization and exchanges of clinical care summaries and medication lists remained limited. New and ongoing policy initiatives and payment reforms may accelerate the electronic exchange of health information by creating new data exchange options, defining standards for interoperability, and creating payment incentives for information sharing across organizational boundaries.

Concepts: Health care, Electronic health record, Health informatics, Exchange, Microsoft Exchange Server, Regional Health Information Organization