Establishing a Central Archive for Transit Passenger Data

This report describes the rationale, background, establishing organization, and future steps of CATPAD, the Central Archive for Transit Passenger Data. The Central Archive for Transit Passenger Data is a repository that collects, indexes, archives, and makes available online the transit survey instruments, data, and reports collected across the country. This resource is unique in its focus on the disaggregated information of individual transit users – information that is critical for a range of transportation planning analyses. In addition, where available, CATPAD contains aggregated information, such as station boardings and service and fare schedules, to provide key context for the disaggregate person-level data. The Central Archive for Transit Passenger Data seeks to overcome the current impediments to accessing transit survey data by providing a single, searchable, internet archive to store and disseminate this valuable information. The Central Archive for Transit Passenger Data explicitly aims to expand the public return on the considerable investment made to gather transit passenger data. The resource is designed from the start to serve the needs of a range of use cases from transportation planners and policy makers to researchers and community advocates. The goal of CATPAD is to make useful data available to inform transit decision making at all levels and to foster ongoing refinement of the nation’s transit network

Approximate Dynamic Response of Light Secondary Systems

John I. Parcel Fund

Death Through Myth

I wrote this paper, Death Through Myth, for Comparative Cosmologies in Spring 2008. In it, I examine three creation myths: the Maya Popol Vuh, the Andean Huarochiri, and the Japanese Kojiki. Through a close reading of the text, I sought to understand each culture’s view on death, with particular emphasis on the soul and its connection to the body. It is my belief that through reading these texts, we as modern interpreters may begin to understand each culture’s concept of death, and perhaps even better understand our own. This paper, despite its esoteric focus, does have broader implications for the human understanding. Death is one of the great questions of the human condition, and these myths show that it has been so since the dawn of history, if not humanity itself. In reading the three disparate creation myths, I believe that I found some common threads of belief, and I definitely found similarities in the more specific concerns about death. Through reading these myths and others, perhaps we as modern, scientific observers, can begin to understand more the psychology which has driven thousands of generations of humans to question something that may well never be understood

Comparing Data Quality and Cost from Three Modes of On-Board Transit Passenger Surveys

This report presents the findings from a research project investigating the relative data quality and administration costs for three different modes of surveying bus passengers that produce results generalizable to the full passenger population. The three modes, all of which used survey methods distributed or administered onboard the transit vehicle, were: self-complete paper surveys, self-complete online surveys, and interviewer-assisted tablet-based surveys. Results from this study indicate several implications for practitioners choosing a survey mode. First, and most importantly, the analysis reinforces the point that there is no single, best survey mode. The choice of mode must depend on an agency’s priorities for what questions most need to be answered, what population groups are most important to represent, and exactly how the agency chooses to define concepts like a “complete” survey or a “usable” address. Findings suggest several general recommendations for current survey practice: (1) online surveys administered via an invitation distributed on the transit vehicle are not a good option; (2) old-fashioned, low-tech paper survey may still be the best option for many bus passenger surveys; (3) changes in survey results that accompany changes in survey methods should be interpreted with caution; and (4) using a new survey method, especially one relying on more complex technologies, may create unexpected glitches

High resolution fMRI of hippocampal subfields and medial temporal cortex during working memory

Computational models combined with electrophysiological studies have informed our understanding about the role of hippocampal subfields (dentate gyrus, DG; CA subfields, subiculum) and Medial Temporal Lobe (MTL) cortex (entorhinal, perirhinal, parahippocampal cortices) during working memory (WM) tasks. Only recently have functional neuroimaging studies begun to examine under which conditions the MTL are recruited for WM processing in humans, but subfield contributions have not been examined in the WM context. High-resolution fMRI is well suited to test hypotheses regarding the recruitment of MTL subregions and hippocampal subfields. This dissertation describes three experiments using high-resolution fMRI to examine the role of hippocampal subfields and MTL structures in humans during WM. Experiment 1 investigated MTL activity when participants performed a task that required encoding and maintaining overlapping and non-overlapping stimulus pairs during WM. During encoding, activity in CA3/DG and CA1 was greater for stimulus pairs with overlapping features. During delay, activity in CA1 and entorhinal cortex was greater for overlapping stimuli. These results indicate that CA3/DG and CA1 support disambiguating overlapping representations while CA1 and entorhinal cortex maintain these overlapping items. Experiment 2 investigated MTL activity when participants performed a WM task that required encoding and maintaining either low or high WM loads. The results show a load effect in entorhinal and perirhinal cortex during the delay period and suggest that these regions act as a buffer for WM by actively maintaining novel information in a capacity-dependent manner. Experiment 3 investigated MTL activity when participants performed a WM task that required maintaining similar and dissimilar items at different loads. Analysis of a load by similarity interaction effect revealed areas of activity localized to the CA1 subfield. CA1 showed greater activity for higher WM loads for dissimilar, but not similar stimuli. Our findings help identify hippocampal and MTL regions that contribute to disambiguation in a WM context and regions that are active in a capacity-dependent manner which may support long-term memory formation. These results help inform our understanding of the contributions of hippocampal subfields and MTL subregions during WM and help translate findings from animal work to the cognitive domain of WM in humans

Opening a New Can of Worms: A Large-Scale RNAi Screen in Planarians

In this issue of Developmental Cell, Reddien et al. describe the first large-scale RNAi screen in freshwater planarians, classic models for regeneration studies. Their work paves the way for a detailed understanding of regeneration and tissue maintenance in these fascinating animals