Error Characteristics of Fiber Distributed Data Interface (FDDI)

Fiber Distributed Data Interface (FDDI) is a 100 megabits per second fiber optic local area network (LAN) standard being developed by the American National Standard Institute (ANSI). We analyze the impact of various design decisions on the error detection capability of the protocol. In particular, we quantify frame error rate, token loss rate, and undetected error rate. Several characteristics of the 32-bit frame check sequence (FCS) polynomial, which is also used in IEEE 802 LAN protocols, are discussed

Paying our Presidents: What do Trustees Value?

[Excerpt] Our study makes use of data from a panel of over 400 private colleges and universities on the salaries and benefits paid to their presidents. These data are reported annually to the Internal Revenue Service on Form 990 by the institutions. The data have been collected by, and reported in, the Chronicle of Higher Education for academic years 1992-93 through 1997-98.7 We use these data through 1996-97 and merge them with data from a number of other sources including the American Association of University Professors, the American Council on Education, Who’s Who in America, the National Association of College and University Business Officers, the Council on Aid to Education, and the National Science Foundation’s CASPAR system. This permits us to estimate salary and compensation level and change equations. The plan of our paper is as follows. We begin by providing some descriptive statistics on the compensation and mobility of American private college and university presidents, as well as on their personal characteristics. The next section estimates a model of the determinants of presidents’ salary and compensation levels. We then exploit the longitudinal nature of our data and present analyses of presidents’ salary and compensation changes. A brief concluding section summarizes our finding

Pre-colonial institutions and socioeconomic development: The case of Latin America

We study the effects of pre-colonial institutions on present-day socioeconomic outcomes for Latin America. Our thesis is that more advanced pre-colonial institutions relate to better socioeconomic outcomes today. We advance that pre-colonial institutions survived to our days thanks to the existence of largely self-governed Amerindian communities in rural Latin America. Amerindians groups with more advanced institutional capacity would have been able to organize and defend their interests in front of national governments; leading to better development outcomes for themselves and for the population at large. We test our thesis with a dataset of 324 sub-national administrative units covering all mainland Latin American countries. Our extensive range of controls covers factors such as climate, location, natural resources, colonial activities and pre-colonial characteristics – plus country fixed effects. Results strongly support our thesis

State and Local Determinants of Employment Outcomes among Individuals with Disabilities

In the United States, employment rates among individuals with disabilities are persistently low but vary substantially. In this study, we examine the relationship between employment outcomes and features of the state and county physical, economic, and policy environment among a national sample of individuals with disabilities. To do so, we merge a set of state- and countylevel environmental variables with data from the 2009–2011 American Community Survey accessed in a U.S. Census Research Data Center. We estimate regression models of employment, work hours, and earnings as a function of health conditions, personal characteristics, and these environmental features. We find that certain environmental variables are significantly associated with employment outcomes. Although the estimated importance of environmental variables is small relative to individual health and personal characteristics, our results suggest that these variables may present barriers or facilitators to employment that can explain some geographic variation in employment outcomes across the United States

Two-year trajectory of fall risk in people with Parkinson disease: a latent class analysis

Published in final edited form as: Arch Phys Med Rehabil. 2016 March ; 97(3): 372–379.e1. doi:10.1016/j.apmr.2015.10.105.OBJECTIVE: To examine fall risk trajectories occurring naturally in a sample of individuals with early to middle stage Parkinson disease (PD). DESIGN: Latent class analysis, specifically growth mixture modeling (GMM), of longitudinal fall risk trajectories. SETTING: Assessments were conducted at 1 of 4 universities. PARTICIPANTS: Community-dwelling participants with PD of a longitudinal cohort study who attended at least 2 of 5 assessments over a 2-year follow-up period (N=230). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Fall risk trajectory (low, medium, or high risk) and stability of fall risk trajectory (stable or fluctuating). Fall risk was determined at 6 monthly intervals using a simple clinical tool based on fall history, freezing of gait, and gait speed. RESULTS: The GMM optimally grouped participants into 3 fall risk trajectories that closely mirrored baseline fall risk status (P=.001). The high fall risk trajectory was most common (42.6%) and included participants with longer and more severe disease and with higher postural instability and gait disability (PIGD) scores than the low and medium fall risk trajectories (P<.001). Fluctuating fall risk (posterior probability <0.8 of belonging to any trajectory) was found in only 22.6% of the sample, most commonly among individuals who were transitioning to PIGD predominance. CONCLUSIONS: Regardless of their baseline characteristics, most participants had clear and stable fall risk trajectories over 2 years. Further investigation is required to determine whether interventions to improve gait and balance may improve fall risk trajectories in people with PD.Supported by the Davis Phinney Foundation, the Parkinson's Disease Foundation, National Institutes of Health (NIH) (grant nos. NIH R01 NS077959 and NIH UL1 TR000448), the Massachusetts and Utah Chapters of the American Parkinson Disease Association (APDA), the Greater St Louis Chapter of the APDA, and the APDA Center for Advanced Research at Washington University. (Davis Phinney Foundation; Parkinson's Disease Foundation; NIH R01 NS077959 - National Institutes of Health (NIH); NIH UL1 TR000448 - National Institutes of Health (NIH); Utah Chapter of the American Parkinson Disease Association (APDA); Greater St Louis Chapter of the APDA; APDA Center for Advanced Research at Washington University; Massachusetts Chapter of the American Parkinson Disease Association (APDA)

Overseas student teaching and national identity: Why go somewhere you feel completely comfortable?

oai:iajiss.journals.sfu.ca:article/10This article presents the findings of a study of emerging perceptions of national identity held by preservice teachers who completed their student teaching overseas. To help them become better global citizens and teachers in this constantly changing and increasingly diverse world, each in a unique international setting, and based on Crèvecoeur’s question, “What is an American?” reflected on what it means to be American in a foreign country and what it is that characterizes national identity in their host country. Several significant thematic findings related to the participants’ perception of national identity that emerged included observations about lifestyle, economic inequality, diversity, politics, religion, patriotism and perspectives on national identity. The most significant conclusion that can be drawn from the findings is that these student teachers were immersed in the experience to such an extent that they were unable to reflect back upon their American national identity. Clearly, the intensity of context in which they found themselves, did not allow them to identify the characteristics of American through their own eyes. When describing American identity, they did so largely from the generally negative perspective of the people they encountered in their host country

School Food Service Costs: Does Location Matter?

Over 30 million lunches and 9.8 million breakfasts are served every day to children in participating American schools through the USDA National School Lunch and School Breakfast Programs. It is challenging for participating local school food authorities (SFAs) to serve appealing, healthful meals while covering food, labor, and other operating costs with USDA reimbursements. But it may be more difficult for some SFAs than others due to cost differences across locations. Analysis of data from a large national sample reveals that after controlling for differences in SFA characteristics, sharp differences in costs remained among rural, urban, and suburban SFAs and across regions. The highest costs occurred in Mid-Atlantic, suburban SFAs and the lowest cost existed in southwest, urban SFAs. Differences in food costs explained the largest share of this variation.school meal costs, cost function, SFA, Food Consumption/Nutrition/Food Safety,

"The American Jewish Committee’s Annual Opinion Surveys: An Assessment of Sample Quality"

The American Jewish Committee (AJC) surveys of Jewish opinion are unique both in being conducted annually and in the subject matter covered. This paper assesses the quality of these samples. I first summarize my earlier findings on the implications of limiting a sample to respondents who answered “Jewish” when asked a screening question about their religion. I then explore how well the AJC samples actually represent the chosen target population of Jews by religion. That exploration rests on public use datasets available for five recent AJC survey years. Outcomes from these five datasets can be compared to one another as well as to outcomes from public use datasets of two other recent national surveys of Jews, especially on the demographic characteristics of the respondents. The paper finds some larger-than-expected differences among AJC samples, and between these and the other two types of datasets. Finally, the paper considers the extent to which these differences matter for the substantive analysis of American Jewish opinion.

Peculiarities of national interests institutionalization in the North American tradition: history and modernity

This article is devoted to the analysis of characteristics of national interests’ institutionalization in the North American tradition, namely the evolution of their legal consolidation and the practice of implementation in modern condition