Lesion boundary segmentation using level set methods

This paper addresses the issue of accurate lesion segmentation in retinal imagery, using level set methods and a novel stopping mechanism - an elementary features scheme. Specifically, the curve propagation is guided by a gradient map built using a combination of histogram equalization and robust statistics. The stopping mechanism uses elementary features gathered as the curve deforms over time, and then using a lesionness measure, defined herein, ’looks back in time’ to find the point at which the curve best fits the real object. We implement the level set using a fast upwind scheme and compare the proposed method against five other segmentation algorithms performed on 50 randomly selected images of exudates with a database of clinician marked-up boundaries as ground truth

Does Alliance Formation between National Labor Unions and National Environmental Organizations Exist?

Does alliance formation between national labor unions and national environmental organizations exist? Seven national labor unions and seven national environmental organizations that are representative of the two movements are selected for examination by this study to address this question. The project gathers and analyzes three types of data: documents on the web sites of the selected organizations, interviews with high ranked officials from many of the organizations examined and the hyperlinks or web links from each organization’s web page. An analysis of the document of the web sites and interviews with high ranking officials identifies three issues that national labor unions and national environmental organizations share: global trade/globalization, corporate accountability and human exposure to toxic chemicals. Next, the study examines the hyperlinks from the web sites to discover if they demonstrate a connection between national labor unions, and national environmental organizations. The study found minimal direct web links between national labor unions and national environmental organizations. From the document analysis of the web sites and the interviews conducted with high ranking officials, Warren’s (1967) typology of coalitional (temporary coalitions) and federative (permanent coalitions) arrangement is used to order the efforts of national labor unions and environmental organizations to work together. The AFL-CIO is included among the assessment of organizations participating in coalitional and federative arrangements. Twenty-one coalitional arrangements and 6 federative arrangements are discovered by this study. The majority of coalitional arrangements and 3 of the 6 federative arrangements are associated with the issue of global trade/globalization. The other coalitional and federative arrangements are associated with the issues of corporate accountability, human exposure to toxic chemicals and energy. The issue of energy as a cooperative issue emerged from the discovered coalitional arrangements. The findings of the study indicate that among national labor unions and national environment organizations, industrial labor unions and environmental lobbying organizations have the greatest success in working together. Overall, the ability of national labor unions and national environmental organizations to work together appears to be limited by their lack of shared issues and their inability to align the frames of the issues they do share. Many indicators suggest that national labor unions and national environmental organizations are moving farther away from working together. Besides the lack of shared issues, the factors of conflicts between the labor and the environmental movements, the difficulty of adopting a social justice frame, the adverse political climate, the relationship of the labor and environmental movements to capital/business, the lack of acknowledging coalitional and federative arrangements, the lack of building federative arrangements, and the general difficulties of trying to work together limit cooperation between national labor unions and national environmental organizations. These findings are discussed using a synthesis of the framing perspective, resource mobilization, and the political process model/political opportunity perspective as suggested by Oliver and Myers (2003). The project concludes with an overview of findings, questions for future research and policy recommendations that could improve the ability of national labor unions and environmental organizations to work together

Role of the church as an intermediary in international conflict: a theological assessment of principled negotiation

This thesis explores the interface between conflict resolution theory and the theology and praxis of the church. One purpose is to demonstrate the value of theological ethics in the development of conflict resolution theory. A second purpose is to select and examine a particular conflict intervention role and assess its applicability as a potential model for the functioning of the church as an intermediary in the resolution of international conflict.The particular theory selected comes from the problem solving school of conflict resolution. At the same time, principled negotiation, developed by the Harvard Negotiation Project of Harvard Law School, has a very pragmatic orientation.This theory's applicability for the church is first assessed by examining two case studies, both examples of nonofficial third party intervention in some aspect of East-West relations during the Cold War. The first case is one where the authors of principled negotiation act as third party interveners. The second case examines the role played by a religious group, the Quakers, in a similar context.The final section of the thesis develops a theology of conciliation with which to assess the applicability of principled negotiation for use by the church. The result is an affirmation of the model's general appropriateness for use by the church. However, various adaptations in both theory and practice are recommended, in order to reflect the theological context within which the church operates and in order to make a contribution to the general development of conflict resolution theory

Transfer of Stimulus Control By Temporal Fading

The present study was designed to analyze the transfer of stimulus control in temporal fading procedures. Several aspects of temporal fading procedures were manipulated including sources of inhibitory stimulus control, delays of reinforcement, and rates of increase in the temporal parameter of a fading procedure. In Experiment I, previous research producing transfer of stimulus control in a temporal fading procedure was directly replicated and controls were implemented for the operation of inhibition. The results showed that inhibitory stimulus control is not necessary in order to produce a transfer as participants with neutral stimulus backgrounds also transferred from one dimension to another without errors. However, positive stimulus backgrounds in the fading procedure prohibited the participants from achieving an errorless transfer of discrimination learning. In Experiment II, a fixed trial duration was employed with a constant and equal delay of reinforcement for both new and original stimulus dimensions. In this condition, participants did not transfer from one dimension to another with up to 30-second delays. Control participants were yoked to participants exposed to delayed and fading procedures to examine response latencies under delayed reinforcement for a simultaneous discrimination. There were no discernible response patterns under this condition except that participants continued to emit relatively short response latencies with a 40-second delay of reinforcement. In Experiment III, the effects of different steps of temporal fading on transfer were examined. The results showed that as the step of delay increased (10 sec. per trial), subjects transferred earlier in the fading series. Also, subjects with extremely low steps of delay (.1 sec. per trial) tended to remain with the original stimulus dimension. Experiments I through III demonstrated the necessity of either inhibitory or neutral stimulus backgrounds, differential delays of reinforcement correlated with each stimulus dimension, and relatively rapid increments in delay of the original stimulus dimension to obtain transfers of stimulus control in temporal fading procedures. When excitatory stimulus backgrounds were employed, or no differential delay of reinforcement was present, or the delay of the original stimulus dimension increased slowly, errorless transfers were not obtained. Overall, the results indicate that temporal fading procedures are a reliable, although complexly controlled, means of obtaining transfer between two stimulus dimensions