Matching Items (51)
Description
Lead is a neurotoxin that has been shown to have a long and lasting impact on the brains, bodies, and behaviors of those who are poisoned. It also has a greater presence in communities with high levels of poverty and minority populations. Compounded over time, the effects of lead poisoning, even at low levels of exposure, impact a child's readiness and ability to learn. To investigate the relationship between the risk of lead poisoning, school level academic achievement, and community demographics, three sets of data were combined. The Lead Poisoning Risk Index (LPRI), used to quantify the risk in each census tract of being poisoned by lead, standardized state assessment data for third grade reading and eighth grade math, and census 2000 demographic data were combined to provide information for all Arizona schools and census tracts. When achievement was analyzed at the school level using descriptive, bivariate correlation, and multivariate regression analyses, lead's impact practically disappeared, exposing the powerful effect of poverty and race on achievement. At a school in Arizona, the higher the percentage of students who are poor or Hispanic, African American or Native American, these analyses' predictive models suggest there will be a greater percentage of students who fail the third grade AIMS reading and eighth grade AIMS math tests. If better achievement results are to be realized, work must be done to mitigate the effects of poverty on the lives of students. In order to improve schools, there needs to be an accounting for the context within which schools operate and a focus on improving the neighborhoods and the quality of life for the families of students.
ContributorsGehrman, Matthew Paul (Author) / Berliner, David C. (Thesis advisor) / Garcia, David (Committee member) / Danzig, Arnold (Committee member) / Arizona State University (Publisher)
Created2011
Description
This study explores the implications of a cultural and language match/mismatch between teachers and their Hispanic students. The study is particularly relevant given the disproportionate percentage of Hispanic students enrolled in Arizona schools who speak Spanish compared to a majority of teachers who are white and speak English. The purpose of the study was to learn how the experiences of matched/mismatched teachers differed in their efforts to connect with Hispanic students and families. The framework for this study relies on culturally responsive practice which suggests that maintaining both cultural and academic excellence for our Hispanic students and families promotes positive learning outcomes in schools. The research is based on case studies of eight teachers at an elementary school with a predominately Hispanic student and parent population. The data included surveys, interviews and lesson observations to assess culturally responsive practices. The results of this study indicated that teachers who share common cultural and language characteristics exhibit significantly more behaviors associated with culturally responsive practice than their mismatched counterparts. Mismatched teachers, however, were able to draw on specific school wide and pedagogical resources associated with culturally responsive practice to help support their students' learning.
ContributorsPriniski, David P (Author) / Garcia, David (Thesis advisor) / Powers, Jeanne (Committee member) / Thomas, Jeff (Committee member) / Arizona State University (Publisher)
Created2012
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
Description
This thesis investigates the environment of support for reclassified English Language Learners (RCELLs) in Arizona schools. Arizona English Language Learner (ELL) policy and pedagogy have been the subjects of research nationwide; many studies demonstrate that ELLs struggle before, during and after participating in Arizona ELL programs (Lillie et al. 2012; Roa 2012; Garcia, Lawton & de Figuieredo 2012; Office of Civil Rights 2012). Despite evidence that the achievement gap between RCELLs and mainstream students is not closing, little information is available about additional language support that RCELLs might receive in mainstream classrooms. This thesis addresses that void of information through: 1) A literature review of the framework of RCELL support, as outlined by the Arizona Department of Education and relevant studies, and 2) a study of teacher and principal opinion about support components for RCELLs and whether such support is adequate. Study findings present that teachers and principals generally believe RCELLs are well-supported, in terms of both the availability and quality of study-defined support components. Yet there is only weak consensus among teachers that support components are adequate. Additionally, teachers' knowledgeability related to important RCELL support components is low, undermining the reliability of teacher responses. The disconnect between participants' optimistic perceptions of support and the external evidence of low RCELL achievement is rationalized by two conjectures. The first is that teachers are not knowledgeable about RCELL support components and cannot accurately gauge the quality of such support. The second is that existing support components are effective at assisting RCELLs with English learning but are not sufficient to close RCELL academic content achievement gaps.
ContributorsKelly, Cary Shepherd (Author) / Garcia, David (Thesis director) / Garcia, Eugene (Committee member) / Seleznow, Steven (Committee member) / Barrett, The Honors College (Contributor) / Department of Economics (Contributor) / W. P. Carey School of Business (Contributor)
Created2014-12
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
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