Functional hybrid rubisco enzymes with plant small subunits and algal large subunits: engineered rbcS cDNA for expression in chlamydomonas.

There has been much interest in the chloroplast-encoded large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) as a target for engineering an increase in net CO(2) fixation in photosynthesis. Improvements in the enzyme would lead to an increase in the production of food, fiber, and renewable energy. Although the large subunit contains the active site, a family of rbcS nuclear genes encodes the Rubisco small subunits, which can also influence the carboxylation catalytic efficiency and CO(2)/O(2) specificity of the enzyme. To further define the role of the small subunit in Rubisco function, small subunits from spinach, Arabidopsis, and sunflower were assembled with algal large subunits by transformation of a Chlamydomonas reinhardtii mutant that lacks the rbcS gene family. Foreign rbcS cDNAs were successfully expressed in Chlamydomonas by fusing them to a Chlamydomonas rbcS transit peptide sequence engineered to contain rbcS introns. Although plant Rubisco generally has greater CO(2)/O(2) specificity but a lower carboxylation V(max) than Chlamydomonas Rubisco, the hybrid enzymes have 3-11% increases in CO(2)/O(2) specificity and retain near normal V(max) values. Thus, small subunits may make a significant contribution to the overall catalytic performance of Rubisco. Despite having normal amounts of catalytically proficient Rubisco, the hybrid mutant strains display reduced levels of photosynthetic growth and lack chloroplast pyrenoids. It appears that small subunits contain the structural elements responsible for targeting Rubisco to the algal pyrenoid, which is the site where CO(2) is concentrated for optimal photosynthesis.This work was supported in part by Grant DE-FG02-00ER15044 from the United States Department of Energy

The Psychology of Dynamic Product Maintenance

The processes that underlie consumer decisions to invest in the maintenance of a durable good over time are examined. The work centers on a hypotheses that consumers make decisions about whether to repair or replace a good that has suffered a decrease in performance through a process that assesses the value of repair actions relative to two points of reference: the normal rate at which the performance of goods declines as they age (age-indexing), and how the timing and cost of the repair compares to parallel norms for repair expenditures (expenditure indexing). We show how these heuristics can be represented by a cognitive algebra that models maintenance decisions as a series of myopic utility-maximization problems. This process yields outcomes that can approximate those that would emerge from an optimal dynamic maintenance policy in some cases, but significantly depart from optimality in others. The algebra is then used to generate a series of predictions about how maintenance decisions may depart from normative benchmarks that are tested in a dynamic computer-pet ownership simulation. Actual maintenance behavior is characterized by a number of biases that are consistent with theoretical predictions, including a seemingly contradictory tendency to undermaintain and prematurely replace goods of superior value when they were acquired, yet be overly reluctant to part with and over-maintain inferior goods. A discussion of the implications of the work for understanding real-world biases in product care and maintenance behavior is offered

Why We Under-Prepare for Hazards

Upon many witnessing the immense destruction caused by Hurricane Katrina in August 2005, feelings of sympathy were coupled with those of puzzlement: how could so much carnage be caused by a hazard that was so predictable? In 2004 the region had the benefit of a full dress rehearsal for Katrina when Hurricane Ivan—another category 5 storm while in the Gulf—triggered full-scale evacuations of the same areas, revealing many of the same weaknesses of preparedness procedures that were observed during Katrina. In addition, just weeks before the storm planners in New Orleans engaged in a training exercise that simulated the impact of a hypothetical hurrican—Pam&mdash:that breached the levees of New Orleans, submerging 87% of the city. Finally, the warnings of impending catastrophe could not have been stronger or more accurate in the days and hours leading up to the storm\u27s landfall. Substantial numbers of residents nevertheless failed to heed urgent warnings to leave, few organized efforts were made to assist those who lacked the means to do so, and governments failed to have sufficient resources in place to deal with the disaster when it was realized

AN ECONOMIC ASSESSMENT OF WETLAND MITIGATION IN NORTHWEST MINNESOTA

The economic efficiency of wetland mitigation in Minnesota's Red River Valley was examined using the Minnesota Routine Assessment Method on ten wetland case studies to rate the functions of impacted and replacement wetlands. Secondary sources were used to assign dollar values to wetland functions of impacted and replacement wetlands. Mitigation costs for projects ranged from $279 to$4,171 per acre. Estimated annual social values ranged from $207 to$1,027 per acre for impacted wetlands and from $268 to$927 per acre for replacement wetlands. Social values of replacement wetlands exceeded the social value of impacted wetlands in seven cases. Values of replacement wetlands were 1.8 to 4 times greater than the values of impacted wetlands due to 2-to-1 replacement ratios. When society gains benefits from mitigation, public cost-sharing may be appropriate. In one case the value of the impacted wetlands was higher than the value of the replacement wetland. There were insufficient data to evaluate two cases. Results are only indicators of efficiency, since not all social costs and benefits of the impact-mitigation activity are addressed by legislation. These results suggest wetland mitigation policy in Minnesota needs to be reevaluated if efficient use of society's resources is a legislative goal.Wetland(s), mitigation, economics, values, Minnesota, Red River, Wetland Conservation Act, Minnesota Routine Assessment Method, restoration, Land Economics/Use,

The Enhancement Bias in Consumer Decisions to Adopt and Utilize Product Innovations

The ability of consumers to anticipate the value they will draw from new product generations that expand the capabilities of incumbent goods is explored. Drawing on previous research in affective forecasting, the work explores a hypothesis that consumers will frequently overestimate the benefits they envision drawing from new added product features and underestimate the learning costs required to realize those benefits. This hypothesis is tested using a computer simulation in which subjects are trained to play a Pacman-like arcade game where icons are moved over a screen by different forms of tactile controls. Respondents are then given the option to play a series of games for money with an incumbent game platform or pay to play with an alternative version that offer either expanded (Experiments 1 and 2) or simplified (Experiment 3) sets of controls. As hypothesized, subjects displayed an upwardly-biased valuation of the new sets of controls as measured by actual versus forecasted usage rates and performance gains. Yet, when given the opportunity to be paid to trade down to a more efficient device in exchange, few accepted. We thus observe a paradox where the presence of forecasting mistakes in product adoptions does little to induce regret in ownership

The Psychology of Intuitive Forecasts of New Product Utility

When faced with the decision to adopt a product or service innovation consumers often need to forecast the long-run utility it will provide relative to incumbent goods. In this paper we review recent psychological research on the ability of people to forecast their own future preferences and discuss its implications for new product adoption decisions. We identify and review evidence for four distinct ways in which new product valuations may depart from those that would be prescribed by normative economic theory: projection biases, telescoping, emotional myopia, and loss framing. One of the implications of these biases is a predicted tendency for consumers to systematically overvalue and overbuy technology—at least under some conditions. We conclude with a discussion of the opportunities—and risks—these biases pose for managers seeking new ways to encourage consumer adoption of novel products and services

Biases in Predicting Preferences for the Whole Visual Patterns from Product Fragments

This research examines the ability of consumers to predict the appeal of complete visual patterns from small sample fragments. In a task designed to mimic the dilemma of choosing wallpaper from small swatches, study participants are shown fragments taken from a large pattern design and are asked to predict how attractive they would find the complete image. Drawing on prior research on affective forecasting, predictions are hypothesized to be driven by an anchoring‐and‐adjustment process that skews forecasts toward the attractiveness of fragments when judged in isolation. Results from 3 laboratory studies support this basic hypothesis: Respondents consistently overestimate the degree to which their initial reactions to fragments predict their subsequent evaluations of wholes. The size of this projection bias is, in turn, conditioned by such moderators as prior familiarity with product fragment, cognitive load, and visualization abilities—effects that are consistent with an anchoring‐and‐adjustment explanation for the data

Rewarding Non-productivity In the Hospitality Industry

The industry has not clearly focused on many important problems, such as rewarding service workers based on productivity. Instead, many industry leaders have focused on straw men issues, issues that are more rhetoric than substance. The authors examine some of these so-called is- sues in detail: governmental wage policies, immigration laws, the quality of the work force, service worker training, and gratuity management, to provide a fresh look at worker productivity beyond the rhetoric and myths that prevai