Matching Items (68)
Description
For over a century, researchers have been investigating collective cognition, in which a group of individuals together process information and act as a single cognitive unit. However, I still know little about circumstances under which groups achieve better (or worse) decisions than individuals. My dissertation research directly addressed this longstanding question, using the house-hunting ant Temnothorax rugatulus as a model system. Here I applied concepts and methods developed in psychology not only to individuals but also to colonies in order to investigate differences of their cognitive abilities. This approach is inspired by the superorganism concept, which sees a tightly integrated insect society as the analog of a single organism. I combined experimental manipulations and models to elucidate the emergent processes of collective cognition. My studies show that groups can achieve superior cognition by sharing the burden of option assessment among members and by integrating information from members using positive feedback. However, the same positive feedback can lock the group into a suboptimal choice in certain circumstances. Although ants are obligately social, my results show that they can be isolated and individually tested on cognitive tasks. In the future, this novel approach will help the field of animal behavior move towards better understanding of collective cognition.
ContributorsSasaki, Takao (Author) / Pratt, Stephen C (Thesis advisor) / Amazeen, Polemnia (Committee member) / Liebig, Jürgen (Committee member) / Janssen, Marco (Committee member) / Fewell, Jennifer (Committee member) / Hölldobler, Bert (Committee member) / Arizona State University (Publisher)
Created2013
Description
The spread of invasive species may be greatly affected by human responses to prior species spread, but models and estimation methods seldom explicitly consider human responses. I investigate the effects of management responses on estimates of invasive species spread rates. To do this, I create an agent-based simulation model of an insect invasion across a county-level citrus landscape. My model provides an approximation of a complex spatial environment while allowing the "truth" to be known. The modeled environment consists of citrus orchards with insect pests dispersing among them. Insects move across the simulation environment infesting orchards, while orchard managers respond by administering insecticide according to analyst-selected behavior profiles and management responses may depend on prior invasion states. Dispersal data is generated in each simulation and used to calculate spread rate via a set of estimators selected for their predominance in the empirical literature. Spread rate is a mechanistic, emergent phenomenon measured at the population level caused by a suite of latent biological, environmental, and anthropogenic. I test the effectiveness of orchard behavior profiles on invasion suppression and evaluate the robustness of the estimators given orchard responses. I find that allowing growers to use future expectations of spread in management decisions leads to reduced spread rates. Acting in a preventative manner by applying insecticide before insects are actually present, orchards are able to lower spread rates more than by reactive behavior alone. Spread rates are highly sensitive to spatial configuration. Spatial configuration is hardly a random process, consisting of many latent factors often not accounted for in spread rate estimation. Not considering these factors may lead to an omitted variables bias and skew estimation results. The ability of spread rate estimators to predict future spread varies considerably between estimators, and with spatial configuration, invader biological parameters, and orchard behavior profile. The model suggests that understanding the latent factors inherent to dispersal is important for selecting phenomenological models of spread and interpreting estimation results. This indicates a need for caution when evaluating spread. Although standard practice, current empirical estimators may both over- and underestimate spread rate in the simulation.
ContributorsShanafelt, David William (Author) / Fenichel, Eli P (Thesis advisor) / Richards, Timothy (Committee member) / Janssen, Marco (Committee member) / Arizona State University (Publisher)
Created2012
DescriptionThis paper provides an analysis of the differences in impacts made by companies that promote their sustainability efforts. A comparison of companies reveals that the ones with greater supply chain influence and larger consumer bases can make more concrete progress in terms of accomplishment for the sustainability realm.
ContributorsBeaubien, Courtney Lynn (Author) / Anderies, John (Thesis director) / Allenby, Brad (Committee member) / Janssen, Marco (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2013-05
Description
The evolution of cooperation is a fundamental problem in biology, especially for non-relatives, where indirect fitness benefits cannot counter within-group inequalities. Multilevel selection models show how cooperation can evolve if it generates a group-level advantage, even when cooperators are disadvantaged within their group. This allows the possibility of group selection, but few examples have been described in nature. Here we show that group selection can explain the evolution of cooperative nest founding in the harvester ant Pogonomyrmex californicus. Through most of this species’ range, colonies are founded by single queens, but in some populations nests are instead founded by cooperative groups of unrelated queens. In mixed groups of cooperative and single-founding queens, we found that aggressive individuals had a survival advantage within their nest, but foundress groups with such non-cooperators died out more often than those with only cooperative members. An agent-based model shows that the between-group advantage of the cooperative phenotype drives it to fixation, despite its within-group disadvantage, but only when population density is high enough to make between-group competition intense. Field data show higher nest density in a population where cooperative founding is common, consistent with greater density driving the evolution of cooperative foundation through group selection.
ContributorsShaffer, Zachary (Author) / Sasaki, Takao (Author) / Haney, Brian (Author) / Janssen, Marco (Author) / Pratt, Stephen (Author) / Fewell, Jennifer (Author) / College of Liberal Arts and Sciences (Contributor)
Created2016-07-28
Description
Climate change presents the urgent need for effective sustainable water management that is capable of preserving natural resources while maintaining economical stability. States like California rely heavily on groundwater pumping for agricultural use, contributing to land subsidence and insufficient returns to water resources. The recent California drought has impacted agricultural production of certain crops. In this thesis, we present an agent-based model of farmers adapting to drought conditions by making crop choice decisions, much like the decisions Californian farmers have made. We use the Netlogo platform to capture the 2D spatial view of an agricultural system with changes in annual rainfall due to drought conditions. The goal of this model is to understand some of the simple rules farmers may follow to self-govern their consumption of a water resource. Farmer agents make their crop decisions based on deficit irrigation crop production function and a net present value discount rate. The farmers choose between a thirsty crop with a high production cost and a dry crop with a low production cost. Simulations results show that farmers switch crops in accordance with limited water and land resources. Farmers can maintain profit and yield by following simple rules of crop switching based on future yields and optimal irrigation. In drought conditions, individual agents expecting lower annual rainfall were able to increase their total profits. The maintenance of crop yield and profit is evidence of successful adaptation when farmers switch to crops that require less water.
ContributorsGokool, Rachael Shanta (Author) / Janssen, Marco (Thesis director) / Eakin, Hallie (Committee member) / School of Human Evolution and Social Change (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Coffee is an important link between the United States and Latin America and an important part of Latin America’s culture and economy. This paper looks at the similarities and differences between coffee organizations in Colombia, Ecuador, Peru, and Guatemala. Colombia has the strongest coffee organizations with the most political power. Guatemala and Peru, to a lesser extent, have well organized and powerful organizations that make up their industry. However, Ecuador has a significantly less organized organization. At their core, each country has a similar structure. There is one organization on the national level that watches out for the industry as a whole. Underneath that, there are smaller, often regional organizations made up of cooperatives pooling their resources for export. They function in similar ways as the national organizations, but have less reach. At the bottom, there are individual cooperatives and independent farmers. These cooperatives do not have much reach or connection to international markets.
ContributorsChabin, James Edward (Author) / Janssen, Marco (Thesis director) / Taylor, Keith (Committee member) / School of Sustainability (Contributor) / School of International Letters and Cultures (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Over the last fifty years, education funding has been litigated and debated in the United States. In an effort to uncover more into the effects of state dollars on education, I used the guiding research question: did differences in state-level education funding trends in the 1990s affect crime rates? With the help of literature on changing education-funding trends, I selected the timeframe of 1990-1995 because some states and jurisdictions increased their funding while others decreased it. For my research, I outlined the independent variable of per pupil expenditures in order to focus directly on the dollars that impact the individual student, and the dependent variables of burglary, robbery, and motor vehicle theft crime rates because juveniles typically commit these crimes. Unemployment rates and household income served as confounding variables, as these economic factors have been proven to affect crime rates. Using the difference-in-difference method, I was able to test the effect of the implementation of a treatment, increased education funding, on my control and treatment group over the 1990-1995-time period. After running a regression on each of my selected juvenile-specific crime rates, I found my results to be inconclusive; however, by factoring in more confounding variables, I believe this quasi-experimental approach can be repeated to find more solid results.
ContributorsWilson, Kelsey Marie (Author) / Dorn, Sherman (Thesis director) / Carter, Heather (Committee member) / Tatto, Maria (Committee member) / School of Public Affairs (Contributor) / School of Politics and Global Studies (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
This study examined perception of K12 schooling systems as experienced by a randomsample of adults in Phoenix, AZ. It explored whether the values purported as key factors
in the American K12 schooling system - as presented in academic literature - were compatible with the lives, interests and goals of ‘users’, student-participants. In addition, it offered opportunity for post-K12 student-participants to share their views on the purposes, goals, and outcomes they held to be important. The sample consisted of 139 post-K12 stu-
dents/individuals residing in Phoenix, AZ. Mean age of student-participants was 29. Results indicated a mismatch between purported K12 schooling goals and important outcomes embedded in the system and values held by the K12 student-participants. The participants in this research generally perceived K12 schooling as valuable, both to themselves and to society at large, but stressed that the deficiencies they perceived in the system were particular to delivery platforms as they relate to the learning styles of students and belonging. Future life skills and success - in and after K12 schooling - whether related to college or not were also of importance. Results revealed that the initial hypothesis of income, age, and ethnicity as
key factors in satisfaction with K12 schooling was not borne-out. Rather it revealed that a sense of belonging and the suitability of learning platforms to the individual learning styles of students were of greatest significance.
ContributorsParker-Anderies, Margaret (Author) / Janssen, Marco (Thesis advisor) / Garcia, David (Committee member) / Mishra, Punya (Committee member) / Arizona State University (Publisher)
Created2022
Description
The transition from high school to college can cause an undue amount of attrition for fully qualified, college-intending first-generation students. Although the students may have overcome multiple obstacles to be accepted to a college and arrive at the transition over summer, it can feel overwhelming to complete the flood of tasks without access to a supportive network to guide and interpret the intricate steps. Many programs focus on college preparation and access to college but do not devote attention to the delicate transition from access to enrollment during the summer months. The term opportunity melt for students who confirm their enrollment and do not enroll in any institution of higher education in the fall semester. This study identified the influence of strategic peer mentor support during the summer months for Chico State students who applied, were admitted, and accepted their college admission. This action research intervention applies key concepts of academic capital theory and follows up on previous cycles of action research in the California State University system to identify barriers for those who intended to enroll but decided not to attend any Cal State or other institution of higher education in the Fall semester after high school graduation.
ContributorsRyan, Shawn (Author) / Dorn, Sherman (Thesis advisor) / Kim, Jeongeun (Committee member) / Weston, Jeffrey (Committee member) / Arizona State University (Publisher)
Created2022
Description
In the Cold War era, educational broadcasting became a new technological instrument in less industrialized countries, to enhance the quality of education. Specifically, the use of mass media in classrooms was starting to be considered a modernized way for developing the educational system in less industrialized regions. This study argues that educational broadcasting in less industrialized areas, including South Korea, reveals the effects of Cold War politics in educational development in many countries. Through the concept of localized modernization, this study highlights American educational aid programs in establishing an educational broadcasting system in a foreign country and its effects on changing the entire educational system focusing on the case of South Korea.
By investigating various archival sources published by governmental agencies, international organizations, and local governments, this dissertation reveals how some less industrialized regions sought to change their educational system by using a new modern technology, educational broadcasting, and how a new educational idea—that the use of mass media in school instruction can change the entire educational system—influenced, changed, and was adopted in these areas.
Although the U.S. Agency for International Development introduced mass media to modernize education, this study shows how local people adapted a new educational broadcasting system to their own purposes and unique circumstances. Korean policymakers and educators agreed with some parts of the U.S. recommended system, but used them for their own needs. The educational broadcasting system in Korea proceeded differently from the U.S. recommended system. The author thus argues that the case of educational broadcasting in South Korea is an example of how local countries constructed their own educational broadcasting systems, how individual countries adapted U.S. systems during the Cold War era to their own needs, and how the localization of the modernization process can be an alternative lens for an overview of the historical pathway of U.S. educational aid projects in the Cold War era.
ContributorsKim, Woo Yeong (Author) / Dorn, Sherman (Thesis advisor) / Silova, Iveta (Committee member) / Powers, Jeanne M. (Committee member) / Arizona State University (Publisher)
Created2022