Dumping and Double Crossing: The (In)Effectiveness of Cost-Based Trade Policy Under Incomplete Information

We argue that the rise of antidumping protection and the proliferation of voluntary export restraints are fundamentally inter-related. We show that both can be explained by a cost-based definition of dumping when the domestic government has incomplete information about the foreign firm's costs. Given that its costs are only imperfectly observed and knowing the government's desire to offer greater protection against competitively priced imports, efficient foreign firms will voluntarily restrain their exports prior to the antidumping investigation. In turn, the VER distorts the government's perception of the foreign firm's efficiency and often leads to undesirably high duties regardless of the foreign firm's efficiency. The clumsy way that duties are levied benefits domestic firms, which explains the popularity of cost-based complaints.

Tariff Policy for a Monopolist Under Incomplete Information

We examine the incentives for a government to levy an optimal tariff on a foreign monopolist. With complete information, the home government uses tariffs to extract rents and therefore implements a policy of discriminatory tariffs entailing higher tariffs on more efficient firms. By contrast if the government is incompletely informed about costs, we show that under reasonable conditions the unique self-enforcing outcome involves pooling where firms export the same quantity regardless of efficiency. Due to the distortions created by incomplete information we find that in general, home country welfare is higher under a policy of uniform tariffs than under one of discriminatory tariffs. Our results suggest that trade policies that are motivated by rent extraction are unlikely to be robust to the introduction of incomplete information.

A universal form of slow dynamics in zero-temperature random-field Ising model

The zero-temperature Glauber dynamics of the random-field Ising model describes various ubiquitous phenomena such as avalanches, hysteresis, and related critical phenomena. Here, for a model on a random graph with a special initial condition, we derive exactly an evolution equation for an order parameter. Through a bifurcation analysis of the obtained equation, we reveal a new class of cooperative slow dynamics with the determination of critical exponents.Comment: 4 pages, 2 figure

In vitro evaluation of shear bond strength of orthodontic stainless steel brackets using transillumination

The objective of this study was to compare the effect of transillumination techniques to conventional light curing on shear bond strength (SBS) and adhesive remnant index (ARI) of orthodontic stainless steel brackets. 240 extracted human maxillary incisors, canines and premolars were randomly separated into four control and four experimental groups, based on tooth type. Labio-lingual thickness was measured. Control groups were light cured from buccal surface and experimental groups from lingual surface (transillumination) from four directions (mesial-distal, incisal-direct, direct, mesial-distal-incisal). SBS was measured using an Instron machine and ARI evaluated by microscopic inspection. Mean SBS on maxillary central incisors was lower when cured from lingual side in comparison with buccal side for three light cure directions, but direct cure direction showed nearly equal SBS. Statistical significance was observed for mesial-distal cure direction only. In contrast to central incisors, lateral incisors showed a higher mean SBS when treated from lingual side, for two cure directions (mesial-distal and incisal-direct) with statistical significance observed only for mesial-distal light cure direction. Mean SBS was lower when cured from lingual direction in comparison with buccal direction for all cure directions for canines and premolars. For canines statistical significance was observed for all directions, except incisal-direct; whereas for premolars statistical significance was observed for direct and mesial-distal-incisal directions only. Transillumination is an effective and clinically acceptable light curing technique for bonding orthodontic stainless steel brackets to maxillary central and lateral incisors. For the other teeth groups (canines and premolars) tested, the mean SBS values, using transillumination light curing fell below the acceptable clinical SBS values, indicating that transillumination is not beneficial in light curing brackets on these teeth

The association between cholesterol levels and brachial/aortic augmentation index versus cognitive status in patients with cardiovascular risk factors

Cardiovascular pathology appears to have a major impact in cognitive decline, and early identification and correction of cardiovascular morbidity could have a major protective impact on cognitive functioning. However, it is not clear how the risk factors for vascular disease can also be risk factors for a general cognitive decline. Regarding cholesterol, its implications in cognitive decline are not very well understood, considering that a high level of cholesterol has been associated with both an increased and decreased risk of dementia. In the present context, we decided to study correlations between cholesterol concentration and the various subdomains of some main psychometric tests, such as MMSE (Mini-Mental State Examination) and MoCA (The Montreal Cognitive Assessment), as well as some measurements for systemic arterial stiffness (brachial and aortic augmentation index) and how they correlate with the aforementioned psychometric parameters. Our results provide additional evidence for a correlation between cholesterol levels and cognitive subdomains (with special focus on orientation, attention, recent memory and long-term memory). Additionally, a significant correlation was found between the brachial and aortic augmentation index and the results of both MMSE and MOCA tests

Phase Transition in a Self-repairing Random Network

We consider a network, bonds of which are being sequentially removed; that is done at random, but conditioned on the system remaining connected (Self-Repairing Bond Percolation SRBP). This model is the simplest representative of a class of random systems for which forming of isolated clusters is forbidden. It qualitatively describes the process of fabrication of artificial porous materials and degradation of strained polymers. We find a phase transition at a finite concentration of bonds $p=p_c$, at which the backbone of the system vanishes; for all $p<p_c$ the network is a dense fractal.Comment: 4 pages, 4 figure

Epigenetic memory in response to environmental stressors

Exposure to environmental stressors, toxicants, and nutrient deficiencies can affect DNA in several ways. Some exposures cause damage and alter the structure of DNA, but there is increasing evidence that the same or other environmental exposures, including those that occur during fetal development in utero, can cause epigenetic effects that modulate DNA function and gene expression. Some epigenetic changes to DNA that affect gene transcription are at least partially reversible (i.e., they can be enzymatically reversed after cessation of exposure to environmental agents), but some epigenetic modifications seem to persist, even for decades. To explain the effects of early life experiences (such as famine and exposures to other stressors) on the long-term persistence of specific patterns of epigenetic modifications, such as DNA methylation, we propose an analogy with immune memory. We propose that an epigenetic memory can be established and maintained in self-renewing stem cell compartments. We suggest that the observations on early life effects on adult diseases and the persistence of methylation changes in smokers support our hypothesis, for which a mechanistic basis, however, needs to be further clarified. We outline a new model based on methylation changes. Although these changes seem to be mainly adaptive, they are also implicated in the pathogenesis and onset of diseases, depending on individual genotypic background and types of subsequent exposures. Elucidating the relationships between the adaptive and maladaptive consequences of the epigenetic modifications that result from complex environmental exposures is a major challenge for current and future research in epigenetics.-Vineis, P., Chatziioannou, A., Cunliffe, V. T., Flanagan, J. M., Hanson, M., Kirsch-Volders, M., Kyrtopoulos, S. Epigenetic memory in response to environmental stressors

The topological relationship between the large-scale attributes and local interaction patterns of complex networks

Recent evidence indicates that the abundance of recurring elementary interaction patterns in complex networks, often called subgraphs or motifs, carry significant information about their function and overall organization. Yet, the underlying reasons for the variable quantity of different subgraph types, their propensity to form clusters, and their relationship with the networks' global organization remain poorly understood. Here we show that a network's large-scale topological organization and its local subgraph structure mutually define and predict each other, as confirmed by direct measurements in five well studied cellular networks. We also demonstrate the inherent existence of two distinct classes of subgraphs, and show that, in contrast to the low-density type II subgraphs, the highly abundant type I subgraphs cannot exist in isolation but must naturally aggregate into subgraph clusters. The identified topological framework may have important implications for our understanding of the origin and function of subgraphs in all complex networks.Comment: pape

Coarse-Graining and Self-Dissimilarity of Complex Networks

Can complex engineered and biological networks be coarse-grained into smaller and more understandable versions in which each node represents an entire pattern in the original network? To address this, we define coarse-graining units (CGU) as connectivity patterns which can serve as the nodes of a coarse-grained network, and present algorithms to detect them. We use this approach to systematically reverse-engineer electronic circuits, forming understandable high-level maps from incomprehensible transistor wiring: first, a coarse-grained version in which each node is a gate made of several transistors is established. Then, the coarse-grained network is itself coarse-grained, resulting in a high-level blueprint in which each node is a circuit-module made of multiple gates. We apply our approach also to a mammalian protein-signaling network, to find a simplified coarse-grained network with three main signaling channels that correspond to cross-interacting MAP-kinase cascades. We find that both biological and electronic networks are 'self-dissimilar', with different network motifs found at each level. The present approach can be used to simplify a wide variety of directed and nondirected, natural and designed networks.Comment: 11 pages, 11 figure