Pakistan’s Nuclear Weapons Program and Implications for US National Security.

This article analyzes Pakistan’s nuclear weapons program and the characteristics of the environment in which the program is nested. These characteristics include Pakistan’s history of internal and external instability; nuclear saber rattling during crises; support for Islamic terrorism in order to advance state goals; indigenous production of many elements of its nuclear forces; possession of delivery and command and control systems with destabilizing characteristics; and finally, nuclear doctrine that appears to advocate first use of nuclear weapons. The article argues that the characteristics of Pakistan’s nuclear weapons program generate threats to US national security interests. The article examines six interrelated and synergistic challenges for US national security: first, Pakistan is engaged in an arms race in Southwest Asia that has negative implications for Pakistan’s stability; second, the threat of nuclear proliferation from Pakistan continues; third, Pakistan’s arsenal characteristics make accidental and/or unauthorized nuclear war more likely; fourth, there is an ongoing possibility of war with India; fifth, Islamist influence is spreading through key sectors of Pakistani society; and finally, there is an increasing danger of state failure in Pakistan

Characteristics of Forms of Autonomy

Th is article recasts our understanding of the forms autonomy may take. Rather than emphasizing a rigid set of defi nitions, the article argues that autonomy forms can be characterized by the aggregate number of issues controlled by the local community (scope), the level of local control over any given issue (depth) and the territorial insularity of the autonomous community. So characterized, autonomies run the gambit from personal to cultural to functional to administrative to legislative. Of course, there are grey areas between these types of autonomy and some agreements may fall somewhere in between. Th e article also further breaks legislative autonomy into strong and weak forms

Post-Uruguay Round GATT/WTO Dispute Settlement: Substance, Strengths, Weaknesses, and Causes for Concern

Dispute settlement under the General Agreement on Tariffs and Trade (“GATT”) has come under increasing strain in recent years. The major powers often ignore GATT dispute settlement decisions which do not comport with their economic interests. This situation undermines the credibility of the GATT and threatens the system\u27s framework. If dispute settlement under the GATT continues to be ineffective as it has been through much of the 1980s and early 1990s, GATT member states (“Members”) may well lose faith in the system, begin reimposing the tariffs that were present before the GATT, thereby risking worldwide trade war and possibly consequences as serious as the Great Depression. [FN1] A primary purpose of the Uruguay Round was revision of the GATT dispute settlement system. This paper analyzes the GATT dispute settlement system arising *170 out of the Uruguay Round. The paper initially examines many of the weaknesses existing in the pre-Uruguay Round GATT dispute settlement system, on both theoretical and empirical levels. The paper then discusses the post-Uruguay Round dispute settlement system and how this system attempts to rectify certain weaknesses of the previous system. Finally, the paper discusses problems of the new dispute settlement system, and comments on some implications of these weaknesses. The paper concludes that the Uruguay Round modifications to the GATT dispute settlement system were incomplete and fail to solve certain core problems

Estimating mutual information and multi--information in large networks

We address the practical problems of estimating the information relations that characterize large networks. Building on methods developed for analysis of the neural code, we show that reliable estimates of mutual information can be obtained with manageable computational effort. The same methods allow estimation of higher order, multi--information terms. These ideas are illustrated by analyses of gene expression, financial markets, and consumer preferences. In each case, information theoretic measures correlate with independent, intuitive measures of the underlying structures in the system

The statistics of contour fragments in natural scenes

Summary: Recent electrophysiology recordings in macaque V4/IT suggest that single neuron response to synthetic closed contours can be largely captured by models which only consider a small number of contour fragments (Brincat and Connor 2004). Motivated by this experimental work, we sought firstly to characterize the statistics of contour fragments in natural scenes, and secondly to generate synthetic images which reflect the measured contour-fragment statistics.

To detect contour fragments, we defined a set of feature detectors which respond only in the presence of two edges co-occurring at a fixed relative angle – implemented as a logical ‘AND’ of two Gabor-like, laplacian-of-gaussian linear filters. We then determined the pairwise correlations of these contour fragments in a natural image ensemble. If efficient coding extends to higher cortical centers and processing in the ventral visual stream can be modeled as a sequence of logical operations on linear shape features, then the pairwise statistics we measure should be informative about neural shape coding. 

Using these statistics directly, it is possible to produce a generative model of simple images which contain the measured statistics. We implemented a modified Ising model and solved the inverse problem of determining the optimal model parameters which satisfy the measured correlations. The resulting Ising-like model of the pairwise statistics can generate the probability of any arrangement of contour fragments as measured in the natural image ensemble. 

As a complementary approach to producing images with naturalistic contour fragment statistics, it is possible to start with a natural scene and isolate the target features. This is achieved by applying our contour fragment detection processing to the single scene and then separately visualizing the fragments detected. This second procedure lends itself to parametric randomization of the generated image.

Narrative Elaboration: The central question guiding our study is how shapes are represented in inferotemporal cortex. To that end, we have investigated natural images in order to motivate experiments capable of targeting the extent to which neural processing of shapes involves representing shapes as combinations of key contour features. To simplify, we are focusing on black-and-white images and prioritizing contour features. This project suggests it is possible to generate synthetic images containing only a select set of contour statistics. Our subsequent goals include conducting collaborative macaque electrophysiology experiments with our generated images as visual stimuli