IMPLICATIONS OF SIZE-SELECTIVE PREDATION AND MATE AVAILABILITY FOR MATING-SYSTEM EXPRESSION AND EVOLUTION IN A HERMAPHRODITIC SNAIL (PHYSA ACUTA)

The evolution of environment-specific trait expression (i.e., phenotypic plasticity) represents a seemingly unbeatable evolutionary strategy because a plastic organism may be able to maximize fitness in multiple environments. Traditionally, studies of adaptive plasticity have examined a single type of environment, but organisms in nature may simultaneously adjust their phenotypes to multiple environments. In a series of experiments, I examined whether predation risk and mate availability interact to affect morphology and life history in a hermaphroditic snail (Physa acuta). Predation risk was expected to induce an investment in defense at the expense of reproduction. Mate availability was expected to affect the age at first reproduction where isolated snails are expected to delay selfing because this snail is a preferential outcrosser with the potential for self-fertilization at the cost of inbreeding depression. To establish the adaptive benefit of the predator-induced changes, I induced snails by rearing them in the presence and absence of chemical cues from predatory crayfish and exposed both phenotypes to selection by lethal crayfish. Crayfish induced an increase in mass and shell thickness, and snails with these traits experienced higher survival when exposed to a lethal predator. Therefore, predator-induced plasticity was favored by selection. To establish the adaptive benefit of delayed selfing, I quantified inbreeding depression by comparing the fitness of selfed and outcrossed snails reared in predator and no-predator environments. Inbreeding depression occurred in both environments and therefore, delayed selfing is favored by selection. I went on to demonstrate that inbreeding depression exists for two types of adaptive plasticity (i.e., delayed selfing and an inducible defense). Both types of inbreeding depression in plasticity may act as important constraints on the evolution of self-fertilization. In general, my results highlight the role of enemies in mating-system evolution and the role of mate availability in the evolution of inducible defenses as well as novel forms of constraint on the evolution of plasticity, including the existence of inbreeding depression in adaptive plasticity

A Flexible Framework for Developing Integrated Models of Transportation Systems Using an Agent-based Approach

AbstractTravel demand, traffic flow and land-use models are typically modeled in a decoupled way, i.e. each of the components is modeled separately assuming that parameters related to the other components are fixed. Moreover, the models are often developed by different groups for different contexts, requirements, etc. In this paper we present a prototype of a software framework which allows the user to develop an integrated simulation of a transportation system and also to link additional models to the new simulation in a standardized way. We use an agent-based approach as the basis of such a model. Integrated transportation system models allow model users to overcome the limitations of traditional aggregated, independent transportation models, particularly with respect to sensitivity to behavioral aspects of the travelers. Another requirement, which the software is to satisfy, is the interoperability of models developed in the new framework with legacy models. By interoperability we mean, that any component of the of the model can be interchanged by a legacy software and be used for the integrated simulation. This would allow disparate research groups working on modeling different aspects of a transportation model to plugnplay their models into the framework and test those as a part of an integrated model of an entire system, providing a benefit to researchers, modelers and institutional users of such models

Improving Communication of Uncertainty and Risk of High-Impact Weather through Innovative Forecaster Workshops

It is challenging to communicate uncertainty for high-impact weather events to the public and decision-makers. As a result, there is an increased emphasis and training within the National Weather Service (NWS) for “impact-based decision support.” A Collaborative Science, Technology, And Research (CSTAR) project led by Stony Brook University (SBU) in collaboration with the Alan Alda Center for Communicating Science, several NWS forecast offices, and NWS operational centers held two workshops at SBU on effective forecast communication of probabilistic information for high-impact weather. Trainers in two 1.5-day workshops helped 15–20 forecasters learn to distill their messages, engage audiences, and more effectively communicate risk and uncertainty to decision-makers, media, and the general public. The novel aspect of the first workshop focused on using improvisational techniques to connect with audiences along with exercises to improve communication skills using short, clear, conversational statements. The same forecasters participated in the second workshop, which focused on matching messages to intended audiences and stakeholder interaction. Using a recent high-impact weather event, representatives in emergency management, TV media, departments of transportation, and emergency services provided feedback on the forecaster oral presentations (2–3 min) and a visual slide. This article describes our innovative workshop approach, illustrates some of the techniques used, and highlights participant feedback

Coordinated Transit Response Planning and Operations Support Tools for Mitigating Impacts of All-Hazard Emergency Events

This report summarizes current computer simulation capabilities and the availability of near-real-time data sources allowing for a novel approach of analyzing and determining optimized responses during disruptions of complex multi-agency transit system. The authors integrated a number of technologies and data sources to detect disruptive transit system performance issues, analyze the impact on overall system-wide performance, and statistically apply the likely traveler choices and responses. The analysis of unaffected transit resources and the provision of temporary resources are then analyzed and optimized to minimize overall impact of the initiating event

Modelling Framework for Regional Integrated Simulation of Transportation Network and Activity-Based Demand (Polaris)

Abstract: Travel demand, traffic flow, network operations and land-use models are typically modeled in a decoupled way, i.e. each of the components is modeled separately assuming the others are fixed. Moreover, the models are often developed by different groups for different contexts, requirement, etc. In this paper we present a prototype of a software framework which allows the user to develop an integrated simulation of a transportation system in a standardized, extensible manner, as well as an implementation of an agent-based planning and network operations micro simulation model using this approach. The project uses an agent-based modeling approach to developing an integrated transportation system model. This allows the model to overcome some of the limitations of traditional aggregated transportation models, particularly with respect to sensitivity to behavioral aspects of the travelers. POLARIS project, then, is intended to develop such an modeling framework and demonstrate the benefits of this approach through the implementation of an integrated travel demand and network operations agent-based micro simulation model. The model is intended to be used in evaluating network operations improvements and I TS implementations from a planning perspective. This paper provides background on the POLARIS modeling framework and details the development of several modules using the framework which form the basis of the planning and operations simulation model. Citation: Auld, J., Hope, M., Ley, H., Xu, B., Zhang, K. & Sokolov, V. (2014). Modelling framework for regional integrated simulation of transportation network and activity-based demand (Polaris). In: Campbell P. and Perez P. (Eds), Proceedings of the International Symposium of Next Generation Infrastructure, 1-4 October 2013, SMART Infrastructure Facility, University of Wollongong, Australia

Senior Travelers' Trip Chaining Behavior: Survey Results and Data Analysis

The research team conducted a survey of travel and activity scheduling behavior to better understand senior citizens’ trip chaining behavior in the Chicago metropolitan area’s most populous counties. The team used an internet-based, prompted recall activity-travel survey using Global Positioning System (GPS) devices to collect activity-travel diaries and other necessary information. This survey was conducted with 112 people living in 101 households in Northeastern Illinois’ Cook, DuPage, Lake, and Will Counties. Because aging is a growing concern among transportation planners, this survey focused especially on the elderly population, with approximately half of the survey sample consisting of elderly households and the remainder of non-elderly households. Each respondent within these households was asked to carry a portable GPS device ideally for 14 consecutive days and upload the collected data to a website at the end of each day to fill in their activity-travel survey questionnaires. The results suggest that GPS surveys have an improved ability to capture trips that are frequently under-reported; the use of prompted recall provides valuable data about the activity planning and scheduling process itself, which is not found in traditional surveys. Analysis of the decision-making process from the collected data reveals that some aspects of elderly travel behavior are intrinsically distinct from those of the younger population. Results indicate that while age does not affect some aspects of activity-travel behavior, it does affect such aspects as planning horizons, trip flexibility, and trip chaining practices. This study’s results can therefore be used to plan more efficient transit services targeting senior travelers and may help change their attitudes toward public transportation.Illinois Department of Transportation ICT R27-50published or submitted for publicationnot peer reviewe

Preferences for travel-based multitasking: Evidence from a survey among public transit users in the Chicago metropolitan area

This paper presents an empirical analysis of a survey among public transit users in the Chicago metropolitan area. The survey collected information about travelers’ general preferences for travel-based multi-tasking during public transit use, revealed preferences for travel-based multi-tasking during a reference trip by public transit in the Chicago metropolitan area and general preferences for travel-based multitasking during the use of ride-hailing services. To analyze the preference data, a rank-ordered logit models is estimated. The findings show that preferences for performing different productive and non-productive tasks while traveling can largely be explained by individual-specific attributes such as age and marital status as well as by trip-specific attributes such as the trip duration and travel party composition. In addition, the survey requested information about the usefulness of travel-based multitasking during the reference trip. Individuals traveling by themselves and for at least twenty minutes are found to be comparatively more likely to have been able to free up time later in the day, as they were able to multitask during the reference trip

Investigating the influence of latent lifestyles on productive travels: Insights into designing autonomous transit system

As a special case of multitasking, travel-based multitasking typically refers to conducting a set of in-vehicle activities while traveling. Travel-based multitasking has an indisputable influence on offering a pleasant travel experience to transit users during their rides, given that they can use their travel time to perform desirable activities and gain benefits in various form. For instance, the in-activities could help the rider free up time from his/her schedule for the day (i.e., a worthwhile use of travel time). In this study, we investigate how the worthwhileness of a travel-based multitasking could be under the influence of: (1) the transit user’s lifestyle, and (2) socio-demographics, and (3) the characteristics of the transit trip. Towards this, we conducted an intercept survey focusing on the transit trips in the Chicago metropolitan area and analyzed it using latent class modeling approach. Per the results, two classes of transit users could be identified: (1) worthwhileness seekers, productively travelers and (2) leisure seekers, occasional worthwhile travelers. The results also suggest travel time, waiting time and walking distance to the transit station, and the set of in-vehicle activities as significant predictors of worthwhile use of travel time. The findings provide insights to policymakers for improving public transit systems in the current form, as well as designing an autonomous mobility system as the future form of public transit