SIMULATING THE PERFORMANCE OF A MULTIPLE EXCHANGE MECHANISM MARKET

Industrial Organization,

Investor Sentiment and Noise Traders: Discount to Net Asset Value in Listed Property Companies in the U.K.

There are parallels between the operation of closed-end funds and in the United Kingdom property companies. In both types of corporations, the market capitalization is commonly less than the net asset value (NAV) of the assets owned by the firms. This article investigates the relationship between the NAV of U.K. property companies and their market capitalizations. We first examine the hypothesis that discounts are the result of agency costs, contingent capital gains tax liability and a number of other firm specific factors. We then examine the hypothesis that discounts result from the interaction of noise traders and rational investors. The evidence suggests that both hypotheses have utility in explaining property company discounts.

Distribution and Source of Barium in Ground Water at Cattaraugus Indian Reservation, Southwestern New York

High concentrations of dissolved barium have been found in ground water from bedrock wells on the Seneca Nation of Indians Reservation on Cattaraugus Creek in southwestern New York. Concentrations in 1982 were as high as 23.0 milligrams per liter , the highest found reported from any natural ground-water system in the world. The highest concentrations are in a bedrock aquifer and in small lenses of saturated gravel between bedrock and the overlying till. The bedrock aquifer is partly confined by silt, clay, and till. The high barium concentrations are attributed to dissolution of the mineral barite (BaSO4), which is present in the bedrock and possibly in overlying silt, clay, or till. The dissolution of barite seems to be controlled by action of sulfate-reducing bacteria, which alter the BaSO4 equilibrium by removing sulfate ions and permitting additional barite to dissolve. Ground water from the surficial, unconsolidated deposits and surface water in streams contain little or no barium. Because barium is chemically similar to calcium, it probably could be removed by cation exchange or treatments similar to those used for water softening. (USGS

Escape path complexity and its context dependency in Pacific blue-eyes (Pseudomugil signifer)

The escape trajectories animals take following a predatory attack appear to show high degrees of apparent 'randomness' - a property that has been described as 'protean behaviour'. Here we present a method of quantifying the escape trajectories of individual animals using a path complexity approach. When fish (Pseudomugil signifer) were attacked either on their own or in groups, we find that an individual's path rapidly increases in entropy (our measure of complexity) following the attack. For individuals on their own, this entropy remains elevated (indicating a more random path) for a sustained period (10 seconds) after the attack, whilst it falls more quickly for individuals in groups. The entropy of the path is context dependent. When attacks towards single fish come from greater distances, a fish's path shows less complexity compared to attacks that come from short range. This context dependency effect did not exist, however, when individuals were in groups. Nor did the path complexity of individuals in groups depend on a fish's local density of neighbours. We separate out the components of speed and direction changes to determine which of these components contributes to the overall increase in path complexity following an attack. We found that both speed and direction measures contribute similarly to an individual's path's complexity in absolute terms. Our work highlights the adaptive behavioural tactics that animals use to avoid predators and also provides a novel method for quantifying the escape trajectories of animals.Comment: 9 page

Structural Studies of Low Temperature Ice Iₕ Using a Central Force Potential Model

The revised central force potentials of Stillinger and Rahman [J. Chem. Phys. 68, 666 (1978)] are used to study the binding energy, structure, and multipole moments of a periodic ice Ih sample with a unit cell of 192 water molecules. The initial configuration for the unit cell has each oxygen in a wurtzite structure and intramolecular H-O-H angles symmetrically positioned in the tetrahedral O-O-O angles. Hydrogens are placed such that the total dipole moment for the unit cell is zero and the diagonal quadrupole moments are small (≲ 10-28 esu cm2). Subject to these restrictions, a static energy minimization on the periodic ice crystal yields an optimal O-O separation, intramolecular O-H distance, and intramolecular H-O-H angle of 2.78, 0.972 A, and 101.0°, respectively. Starting from this idealized wurtzite configuration, Metropolis Monte Carlo runs on the periodic system are made at 20 and 200 K. At 20 K, the equilibrated system has an average intermolecular potential energy per molecule of -15.2 kcal/mol and structure factors which have decreased to about 80% of the initial values. The dipole moment for the unit cell is ≃3 D. The equilibrated system at 200 K appears to be modified only by temperature dependent vibrational effects

Predicting effects of environmental change on a migratory herbivore

Changes in climate, food abundance and disturbance from humans threaten the ability of species to successfully use stopover sites and migrate between non-breeding and breeding areas. To devise successful conservation strategies for migratory species we need to be able to predict how such changes will affect both individuals and populations. Such predictions should ideally be process-based, focusing on the mechanisms through which changes alter individual physiological state and behavior. In this study we use a process-based model to evaluate how Black Brant (Branta bernicla nigricans) foraging on common eelgrass (Zostera marina) at a stopover site (Humboldt Bay, USA), may be affected by changes in sea level, food abundance and disturbance. The model is individual-based, with empirically based parameters, and incorporates the immigration of birds into the site, tidal changes in availability of eelgrass, seasonal and depth-related changes in eelgrass biomass, foraging behavior and energetics of the birds, and their mass- dependent decisions to emigrate. The model is validated by comparing predictions to observations across a range of system properties including the time birds spent foraging, probability of birds emigrating, mean stopover duration, peak bird numbers, rates of mass gain and distribution of birds within the site: all 11 predictions were within 35% of the observed value, and 8 within 20%. The model predicted that the eelgrass within the site could potentially support up to five times as many birds as currently use the site. Future predictions indicated that the rate of mass gain and mean stopover duration were relatively insensitive to sea level rise over the next 100 years, primarily because eelgrass habitat could redistribute shoreward into intertidal mudflats within the site to compensate for higher sea levels. In contrast, the rate of mass gain and mean stopover duration were sensitive to changes in total eelgrass biomass and the percentage of time for which birds were disturbed. We discuss the consequences of these predictions for Black Brant conservation. A wide range of migratory species responses are expected in response to environmental change. Process-based models are potential tools to predict such responses and understand the mechanisms which underpin them

Assessment of airway inflammation using sputum, BAL, and endobronchial biopsies in current and ex-smokers with established COPD

Rationale: Smoking effects on physiological and gross pathology in chronic obstructive pulmonary disease (COPD) are relatively well described. However, there is little known in COPD about the detailed interrelationships between lung function and inflammatory profiles in different airway compartments from the same individual and whether airway inflammation in these different compartments differs in ex- and current smokers with established COPD. Objectives: We compared sputum, bronchoalveolar (BAL), and airway wall inflammatory profiles in current versus ex-smokers and related this to smoking intensity and lung function in 17 current and 17 ex-smokers with mild to moderate COPD. Results: Current smokers had more sputum mast cells (% differential and absolute numbers), whereas ex-smokers had increased sputum neutrophils. In BAL, there was a significant increase in eosinophils in current smokers, but ex-smokers had significantly increased neutrophils, lymphocytes, and epithelial cells. There were no cell profile differences observed in airway biopsies between current and ex-smokers and there were no correlations between the individual inflammatory cell populations in any of the airway compartments. In current smokers only, smoking intensity was negatively correlated with lung function, and associated with a reduction in overall cellularity of both sputum and BAL. Conclusion: Airway inflammation persists in ex-smokers with COPD, but differs from COPD current smokers. The impact of smoking appears to vary in different airway compartments and any direct relationships between cellularity and lung function tended to be negative, ie, worse lung function indicated the presence of fewer cells