Social network architecture and the maintenance of deleterious cultural traits.

How have changes in communications technology affected the way that misinformation spreads through a population and persists? To what extent do differences in the architecture of social networks affect the spread of misinformation, relative to the rates and rules by which individuals transmit or eliminate different pieces of information (cultural traits)? Here, we use analytical models and individual-based simulations to study how a 'cultural load' of misinformation can be maintained in a population under a balance between social transmission and selective elimination of cultural traits with low intrinsic value. While considerable research has explored how network architecture affects percolation processes, we find that the relative rates at which individuals transmit or eliminate traits can have much more profound impacts on the cultural load than differences in network architecture. In particular, the cultural load is insensitive to correlations between an individual's network degree and rate of elimination when these quantities vary among individuals. Taken together, these results suggest that changes in communications technology may have influenced cultural evolution more strongly through changes in the amount of information flow, rather than the details of who is connected to whom.

The co-evolution of social institutions, demography, and large-scale human cooperation.

Human cooperation is typically coordinated by institutions, which determine the outcome structure of the social interactions individuals engage in. Explaining the Neolithic transition from small- to large-scale societies involves understanding how these institutions co-evolve with demography. We study this using a demographically explicit model of institution formation in a patch-structured population. Each patch supports both social and asocial niches. Social individuals create an institution, at a cost to themselves, by negotiating how much of the costly public good provided by cooperators is invested into sanctioning defectors. The remainder of their public good is invested in technology that increases carrying capacity, such as irrigation systems. We show that social individuals can invade a population of asocials, and form institutions that support high levels of cooperation. We then demonstrate conditions where the co-evolution of cooperation, institutions, and demographic carrying capacity creates a transition from small- to large-scale social groups.

Status of the Iowa Workforce and Economy, January 2015

Iowa Workforce Development's newsletter.

Modeling Merging Behavior at Lane Drops, InTrans Projects 13-466 and 06-277, 2015

In work-zone configurations where lane drops are present, merging of traffic at the taper presents an operational concern. In addition, as flow through the work zone is reduced, the relative traffic safety of the work zone is also reduced. Improving work-zone flow-through merge points depends on the behavior of individual drivers. By better understanding driver behavior, traffic control plans, work zone policies, and countermeasures can be better targeted to reinforce desirable lane closure merging behavior, leading to both improved safety and work-zone capacity. The researchers collected data for two work-zone scenarios that included lane drops with one scenario on the Interstate and the other on an urban arterial roadway. The researchers then modeled and calibrated these scenarios in VISSIM using real-world speeds, travel times, queue lengths, and merging behaviors (percentage of vehicles merging upstream and near the merge point). Once built and calibrated, the researchers modeled strategies for various countermeasures in the two work zones. The models were then used to test and evaluate how various merging strategies affect safety and operations at the merge areas in these two work zones.

Status of the Iowa Workforce and Economy, February 2015

Iowa Workforce Development's newsletter.

State Plan for Library Program under Library Services and Construction Act, as amended, 1966

This document includes the general provisions and regulations of the Iowa Sate Traveling Library under the Library Services and Construction Act. It also includes information of appropriations of funds available for expenditure, authority of local agencies to administer and state agency to supervise local administration and certification.

Status of the Iowa Workforce and Economy, March 2015

Iowa Workforce Development's newsletter.

Farm Families Alive and Well, April 2015, Vol. 21, no. 2

News from Iowa’s Center for Agricultural Safety and Health (I-CASH)

Farm Families Alive and Well, June 2015, Vol. 21, no. 3

News from Iowa’s Center for Agricultural Safety and Health (I-CASH)

Status of the Iowa Workforce and Economy, June 2015

Iowa Workforce Development's newsletter.

Status of the Iowa Workforce and Economy, July 2015

Iowa Workforce Development's newsletter.

Farm Families Alive and Well, September 2015, Vol. 21, no. 4

News from Iowa’s Center for Agricultural Safety and Health (I-CASH)

Status of the Iowa Workforce and Economy, September 2015

Iowa Workforce Development's newsletter.

Status of the Iowa Workforce and Economy, October 2015

Iowa Workforce Development's newsletter.