Bidding Behavior and Decision Costs in Field Experiments

Whether rationality of economic behavior increases with expected payoffs and decreases with the cognitive cost it takes to formulate an optimal strategy remains an open question. We explore these issues with field data, using individual bids from sealed-bid auctions in which we sold nearly $10,000 worth of sports cards. Our results incdicate that stakes do indeed matter, as high-priced ($70) cards produced more of the theoretically predicted strategic behavior than did lower-priced ($3) cards. We find additional evidence consistent with the importance of cognitive costs, as subjects more experienced with sports card auctions exhibited a greater tendency to behave strategically than did less experienced bidders.

Fibrin clot structure remains unaffected in young, healthy individuals after transient exposure to diesel exhaust

Exposure to urban particulate matter has been associated with an increased risk of cardiovascular disease and thrombosis. We studied the effects of transient exposure to diesel particles on fibrin clot structure of 16 healthy individuals (age 21-44). The subjects were randomly exposed to diesel exhaust and filtered air on two separate occasions. Blood samples were collected before exposure, and 2 and 6 hours after exposure. There were no significant changes on clot permeability, maximum turbidity, lag time, fibre diameter, fibre density and fibrinogen level between samples taken after diesel exhaust exposure and samples taken after filtered air exposure. These data show that there are no prothrombotic changes in fibrin clot structure in young, healthy individuals exposed to diesel exhaust.</p

Efficient Design and Analysis of Lightweight Reinforced Core Sandwich and PRSEUS Structures

Design, analysis, and sizing methods for two novel structural panel concepts have been developed and incorporated into the HyperSizer Structural Sizing Software. Reinforced Core Sandwich (RCS) panels consist of a foam core with reinforcing composite webs connecting composite facesheets. Boeing s Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) panels use a pultruded unidirectional composite rod to provide axial stiffness along with integrated transverse frames and stitching. Both of these structural concepts are ovencured and have shown great promise applications in lightweight structures, but have suffered from the lack of efficient sizing capabilities similar to those that exist for honeycomb sandwich, foam sandwich, hat stiffened, and other, more traditional concepts. Now, with accurate design methods for RCS and PRSEUS panels available in HyperSizer, these concepts can be traded and used in designs as is done with the more traditional structural concepts. The methods developed to enable sizing of RCS and PRSEUS are outlined, as are results showing the validity and utility of the methods. Applications include several large NASA heavy lift launch vehicle structures

Líquenes corticícolas en el caribe colombiano

Se documentó la composición de la flora liquénica corticícola de cinco localidades de la región Caribe colombiana, tres de tierras bajas (planicies) y dos de tierras altas (macizos montañosos). Se encontraron 348 morfoespecies de líquenes corticícolas, basadas en 950 ejemplares, de las cuales 215 se determinaron a nivel de especie y 62 a género (debido a la ausencia de estructuras reproductivas o a la carencia de trabajos taxonómicos). El resto de las especies (71) constituyó un grupo líquenes costrosos estériles que carecen de caracteres específicos para su identificación. Se encontraron 115 registros nuevos para Colombia, la mayoría de especies son registros nuevos para las áreas de estudio. El número total de especies para la región Caribe, incluyendo los estudios previos de macrolíquenes y líquenes foliícolas, se estimó en aproximadamente 400

Multi-disciplinary Lessons Learned from Low-Tech Coral Farming and Reef Rehabilitation: II. Coral Demography and Social-Ecological Benefits

Low-tech coral farming and reef rehabilitation have become important tools to foster community-based participation in the management of coastal social-ecological systems. Lessons learned from coral demographic dynamics, ecosystem-level benefits, and sociological dynamics achieved in Culebra Island, Puerto Rico, are discussed. Important gaps regarding social-ecological interactions are also addressed. Coral reef rehabilitation efforts must be adaptive and focused on maximizing resilience as a long-term goal, with emphasis on managing non-linear dynamics, thresholds, environmental and climate uncertainty, and ecological surprises. In this context, coral demographic modelling becomes fundamental to address, not only ecological, but also sociological concerns. Only through sustained support and input of harvested corals restored populations, and by increasing the spatial scale of reef rehabilitation, restored populations can remain viable and grow under present and projected environmental and climate conditions. Understanding sociological dynamics, learning from others experiences, integrating visioning and scenario building, leadership building, multi-sectorial agents and actor groups, and strengthening cross-sectorial social networking are necessary adaptive approaches to cope with future environmental and climate changes, and are an integral part of reef rehabilitation. The combined benefits to social-ecological systems are multiple. With proper planning, design, funding, local support, and implementation, these can have long-lasting impacts in restoring coastal resilience

Are Subjects Making Financial Decisions in Lab Auctions or Are They Just Gambling?

Optimal bidding strategies in first-price and Dutch auctions are theoretically isomorphic but depend on bidder risk attitudes. However, laboratory experiments consistently find different behaviour between auction formats. This article explores whether the notion in psychology that financial and gambling risks are viewed differently can explain the discrepancy. Ultimately, the evidence does not support this hypothesis, but a bidder\u27s propensity to gamble is associated with how much risk he takes in both auctions whereas his propensity to take financial risks is not. The results suggest that subjects may view themselves as gambling in laboratory auctions rather than making financial decisions

Beyond patency: functional assessment of adequacy using internal mammary artery grafting to the left anterior descending artery

Introduction Arterial graft physiology influences the long‐term outcome of coronary artery bypass grafting (CABG). We studied factors that can affect the overall resistance to flow using internal mammary artery grafting to the left anterior descending artery. Methods This was a prospective, nonrandomized observational study of 100 consecutive patients who underwent elective on‐pump isolated or combined valve surgery and CABG. Coronary stenoses were assessed using conventional and quantitative coronary angiography assessment. The flow and pulsatility index (PI) of the grafts were assessed by transit‐time flowmetry during cardioplegic arrest and at the end of the operation. Fractional polynomials were used to explore linearity, followed by multivariable regression analysis. Results Univariate analysis demonstrated higher flows at the end of the operation in patients who had higher flows with the cross‐clamp on (P

Role of shear stress and tPA concentration in the fibrinolytic potential of thrombi

Funding: This research was funded by British Heart Foundation PG/08/127/26517 awarded to N.A.B. and D.E.N. C.S.W. and N.J.M. were supported by the British Heart Foundation project grants (PG/15/82/31721 and PG/20/17/35050). D.E.N. and A.J.L. were supported by the British Heart Foundation project grant PG/04/131/18118. D.E.N. is supported by the British Heart Foundation (CH/09/002, RE/18/5/34216, RG/16/10/32375) and is the recipient of a Wellcome Trust Senior Investigator Award (WT103782AIA).Peer reviewedPublisher PD