Information measures and cognitive limits in multilayer navigation

Cities and their transportation systems become increasingly complex and multimodal as they grow, and it is natural to wonder if it is possible to quantitatively characterize our difficulty to navigate in them and whether such navigation exceeds our cognitive limits. A transition between different searching strategies for navigating in metropolitan maps has been observed for large, complex metropolitan networks. This evidence suggests the existence of another limit associated to the cognitive overload and caused by large amounts of information to process. In this light, we analyzed the world's 15 largest metropolitan networks and estimated the information limit for determining a trip in a transportation system to be on the order of 8 bits. Similar to the "Dunbar number," which represents a limit to the size of an individual's friendship circle, our cognitive limit suggests that maps should not consist of more than about $250$ connections points to be easily readable. We also show that including connections with other transportation modes dramatically increases the information needed to navigate in multilayer transportation networks: in large cities such as New York, Paris, and Tokyo, more than $80\%$ of trips are above the 8-bit limit. Multimodal transportation systems in large cities have thus already exceeded human cognitive limits and consequently the traditional view of navigation in cities has to be revised substantially.Comment: 16 pages+9 pages of supplementary materia

United States Sophistry on the Palestinian Resolution for Statehood

This project examines the rhetorical devices and practices used by the Obama Administration to express and construct opposition to the Palestinian Authority’s statehood bid. This study focuses on uncovering the ideology embedded within President Obama’s Speech to the United Nations General Assembly during the opening of the 66th Session. By conducting an ideology rhetorical analysis of this text, this examination will uncover the reasoning that Obama deploys to make sense of and define the Israeli-Palestinian conflict, and more specifically, the Palestinian bid for statehood. This ideology has contributed to the perpetuation of the Israeli occupation of the Palestinian territories; thereby, denying the Palestinians the right to self-determination. This thesis is organized as follows: Section I introduces Obamas’s speech to the UNGA through a brief overview of the text and outlines my analyses’ goals. Section II contextualizes the history of the Israeli-Palestinian conflict and summarizes Obama’s speech to the UNGA. Section III presents a description of the ideological approach to rhetorical criticism, contributions to the field of ideological criticism, examples of the method’s application, and a rationale for its selection. Section IV reports the findings of my analysis of Obama’s speech to the UNGA and evaluates the contribution that my analysis makes to the understanding of the Israeli-Palestinian conflict. Section V provides a brief update on Palestine’s UN bid following Obama’s speech

Parent-Teacher Perceptions of the Factors That Interfere with Productive Parent-Teacher Relationships in Urban Schools

The main premise of this study is that teachers and parents (that is, single head-of-household mothers) of Black males living in urban communities should engage in collaborative, mutual, and respectful dialogue. A barrier to fostering such collaboration, however, lies in differences between the worldviews of teachers and parents based on a variety of cultural, social, economic, and individual factors. If external and/or internal barriers to developing a productive parent-teacher relationship can be overcome, Black males will have a significantly greater chance of succeeding in school. Therefore, the purpose of this study is to explore the perceptions of single African American mothers (N = 24), African American teachers (N = 12) and White European American teachers (N = 12) as a means of better understanding the factors that may or may not influence the parent-teacher relationship. NVivo was utilized as the data analysis program for the semi-structured interview methods employed to collect data on the perceptions of the participants. The overall arching research question is, “Do poor/working class African American female mothers who are head of households experience certain internal and external factors that influence relationships with teachers and school administrators when intervening on behalf of their adolescent sons”? The data for this study appears to support this overall question with a definitive “Yes”. However, results don’t appear to provide a high percentage of “nodes” and or language that supports concrete evidence for the underlying theories that define class consciousness as the problem. There were a few parents and teachers who specifically seemed to use language that would appear to support differences in class. In conclusion, this study appears to be indicative of past literature that supports the idea that class, not race, is a determinant when looking at how parents intervene and interact with teachers on behalf of their children’s academic progress

Low-level visual processing and its relation to neurological disease

Retinal neurons extract changes in image intensity across space, time, and wavelength. Retinal signal is transmitted to the early visual cortex, where the processing of low-level visual information occurs. The fundamental nature of these early visual pathways means that they are often compromised by neurological disease. This thesis had two aims. First, it aimed to investigate changes in visual processing in response to Parkinson’s disease (PD) by using electrophysiological recordings from animal models. Second, it aimed to use functional magnetic resonance imaging (fMRI) to investigate how low-level visual processes are represented in healthy human visual cortex, focusing on two pathways often compromised in disease; the magnocellular pathway and chromatic S-cone pathway. First, we identified a pathological mechanism of excitotoxicity in the visual system of Drosophila PD models. Next, we found that we could apply machine learning classifiers to multivariate visual response profiles recorded from the eye and brain of Drosophila and rodent PD models to accurately classify these animals into their correct class. Using fMRI and psychophysics, found that measurements of temporal contrast sensitivity differ as a function of visual space, with peripherally tuned voxels in early visual areas showing increased contrast sensitivity at a high temporal frequency. Finally, we used 7T fMRI to investigate systematic differences in achromatic and S-cone population receptive field (pRF) size estimates in the visual cortex of healthy humans. Unfortunately, we could not replicate the fundamental effect of pRF size increasing with eccentricity, indicating complications with our data and stimulus

Multilayer Networks

In most natural and engineered systems, a set of entities interact with each other in complicated patterns that can encompass multiple types of relationships, change in time, and include other types of complications. Such systems include multiple subsystems and layers of connectivity, and it is important to take such "multilayer" features into account to try to improve our understanding of complex systems. Consequently, it is necessary to generalize "traditional" network theory by developing (and validating) a framework and associated tools to study multilayer systems in a comprehensive fashion. The origins of such efforts date back several decades and arose in multiple disciplines, and now the study of multilayer networks has become one of the most important directions in network science. In this paper, we discuss the history of multilayer networks (and related concepts) and review the exploding body of work on such networks. To unify the disparate terminology in the large body of recent work, we discuss a general framework for multilayer networks, construct a dictionary of terminology to relate the numerous existing concepts to each other, and provide a thorough discussion that compares, contrasts, and translates between related notions such as multilayer networks, multiplex networks, interdependent networks, networks of networks, and many others. We also survey and discuss existing data sets that can be represented as multilayer networks. We review attempts to generalize single-layer-network diagnostics to multilayer networks. We also discuss the rapidly expanding research on multilayer-network models and notions like community structure, connected components, tensor decompositions, and various types of dynamical processes on multilayer networks. We conclude with a summary and an outlook.Comment: Working paper; 59 pages, 8 figure

Kilowatt-Class Fission Power Systems for Science and Human Precursor Missions

Nuclear power provides an enabling capability for NASA missions that might otherwise be constrained by power availability, mission duration, or operational robustness. NASA and the Department of Energy (DOE) are developing fission power technology to serve a wide range of future space uses. Advantages include lower mass, longer life, and greater mission flexibility than competing power system options. Kilowatt-class fission systems, designated "Kilopower," were conceived to address the need for systems to fill the gap above the current 100-Wclass radioisotope power systems being developed for science missions and below the typical 100-kWe-class reactor power systems being developed for human exploration missions. This paper reviews the current fission technology project and examines some Kilopower concepts that could be used to support future science missions or human precursors

Developing a GamePlan: Libraries and Campus Athletic Departments

At a number of academic libraries, librarians have begun partnering with Athletic Departments to deliver information literacy to freshman athletes. This breakout session will present three different endeavors designed to meet the needs of the incoming student athlete. UCLA’s College Library has recently expanded collaboration with their athletic department from an annual one-shot for incoming football players to an ongoing partnership integrating library instruction and awareness into the freshman football and basketball teams’ total academic experience. Arizona State University faced two challenges: help student-athletes learn to use the Library\u27s resources, and train their tutors and mentors. Every ASU freshman athlete takes a one-credit Life Skills course, and working in collaboration with the Office of Student Athlete Development, the Instruction team had the unprecedented opportunity to help design the curriculum for a library-focused unit that would not only teach the athletes and their academic coaches about the available resources, but also require the students to write a reflective essay on the experience of searching for relevant information in a library resource. At Willamette University, the librarians have worked with the Athletic Department to create a program called “GamePlan”. The program, which now includes football, crew, basketball, soccer and volleyball teams, is in its third year. Each Fall semester is treated as an “information challenge”, broken up into seven different 20-minute sessions. The sessions, held in the evenings, are focused on individual topics with explicit objectives