MAINE'S LOBSTER FISHERY - MANAGING A COMMON PROPERTY RESOURCE

Resource /Energy Economics and Policy,

A computer simulation of oscillatory behavior in primary visual cortex

Periodic variations in correlated cellular activity have been observed in many regions of the cerebral cortex. The recent discovery of stimulus-dependent, spatially-coherent oscillations in primary visual cortex of the cat has led to suggestions of neural information encoding schemes based on phase and/or frequency variation. To explore the mechanisms underlying this behavior and their possible functional consequences, we have developed a realistic neural model, based on structural features of visual cortex, which replicates observed oscillatory phenomena. In the model, this oscillatory behavior emerges directly from the structure of the cortical network and the properties of its intrinsic neurons; however, phase coherence is shown to be an average phenomenon seen only when measurements are made over multiple trials. Because average coherence does not ensure synchrony of firing over the course of single stimuli, oscillatory phase may not be a robust strategy for directly encoding stimulus-specific information. Instead, the phase and frequency of cortical oscillations may reflect the coordination of general computational processes within and between cortical areas. Under this interpretation, coherence emerges as a result of horizontal interactions that could be involved in the formation of receptive field properties

Testing isomorphism of graded algebras

We present a new algorithm to decide isomorphism between finite graded algebras. For a broad class of nilpotent Lie algebras, we demonstrate that it runs in time polynomial in the order of the input algebras. We introduce heuristics that often dramatically improve the performance of the algorithm and report on an implementation in Magma

Alien Registration- Wilson, James A. (Lewiston, Androscoggin County)

https://digitalmaine.com/alien_docs/26778/thumbnail.jp

A Model of Adaptive Behavior in the New England Fishing Industry, Report to the National Science Foundation, Volume III

This volume is the third in a three volume series of reports submitted to the National Science Foundation for a project entitled University of Rhode Island, University of Maine Study of Social and Cultural Aspects of Fisheries Management Under Extended Jurisdiction (N.S.F. Grant Number AER77-060l8). This project was funded through the RANN Directorate of N.S.F. (Research Applied to National Needs), and was designed to provide data on social, cultural, and economic aspects of the New England fishinq scene which would be of value to those in industry and government concerned with managing the marine fisheries of the northeastern part of the United States, particularly those concerned with management under PL 94-265, the Fisheries Conservation and Management Act of 1976

Options for Managing Maine’s Fisheries: Fisheries Management from an Ecological Perspective

Jim Wilson counters the concerns raised by Ralph Townsend [this issue].The current policy course set by Marine Resources Commissioner Robin Alden is based on an approach to fisheries management which redefines the sustainability problem as an ecosystem problem. Wilson argues that, within this new paradigm, questions such as “how, when, and where” to fish (or not fish) are much more central than species-specific quota setting. These questions not only change the rules under which co-management is implemented but also may improve fisheries management in ways that quota systems have failed, that is the long term conservation of species and habitats

Melanism as a potential thermal benefit in eastern fox squirrels (Sciurus niger)

Melanistic fox squirrels (Sciurus niger) have expanded westward and increased in frequency in the Omaha, Nebraska, and Council Bluffs, Iowa, metropolitan areas. The selective advantage of melanism is currently unknown, but thermal advantages have been hypothesized, especially in winter. No difference in metabolic response curves were measured between melanistic (black) and rufus (orange) fox squirrels. When exposed to sunny skies, both melanistic and rufus squirrels had higher surface (skin and fur) temperature as ambient temperatures increased. Melanistic squirrel surface temperatures did not differ when squirrels were exposed to sunny or cloudy skies. However, rufus individuals showed significantly lower increases in surface temperatures when under cloudy skies. During fall months, rufus individuals were about 1.5 times more active throughout the day than melanistic individuals. However, in winter, melanistic fox squirrels were approximately 30% more active in the mornings (before 13:00) compared to rufus squirrels. Pre-winter body condition was higher in melanistic (25.5 ± 1.8 g/cm) compared to rufus (20.30 ± 3.6 g/cm) fox squirrels; however, there were no significant differences between melanistic (22.8 ± 1.4 g/cm) and rufus (23.9 ± 0.8 g/cm) fox squirrel post-winter body condition. The results of this study indicate that melanistic fox squirrels may have a slight winter thermal advantage over rufus fox squirrels by maintaining higher skin temperatures