PRICE DYNAMICS, INFORMATIONAL EFFICIENCY, AND WEALTH DISTRIBUTION IN CONTINUOUS DOUBLE-AUCTION MARKETS

This paper studies the properties of the continuous double-auction trading mechanism using an artificial market populated by heterogeneous computational agents. In particular, we investigate how changes in the population of traders and in market microstructure characteristics affect price dynamics, information dissemination, and distribution of wealth across agents. In our computer-simulated market only a small fraction of the population observe the risky asset's fundamental value with noise, while the rest of the agents try to forecast the asset's price from past transaction data. In contrast to other artificial markets, we assume that the risky asset pays no dividend, thus agents cannot learn from past transaction prices and subsequent dividend payments. We find that private information can effectively disseminate in the market unless market regulation prevents informed investors from short selling or borrowing the asset, and these investors do not constitute a critical mass. In such case, not only are markets less efficient informationally, but may even experience crashes and bubbles. Finally, increased informational efficiency has a negative impact on informed agents' trading profits and a positive impact on artificial intelligent agents' profits.     

Effects of pure oxygen atmosphere in vivo on plasma lecithin-cholesterol acyltransferase reaction

Exposure to pure oxygen atmospheres for more than three days resulted in loss of red blood cell mass in astronauts in some flights. Oxidation of lipid or protein membrane components may account for this phenomenon, since tocopherol deficient red blood cells have been shown to hemolyze on exposure to elevated oxygen pressures in vitro and in vivo. An additional contributing cause to the induced red cell loss may be the inhibition of the plasma lecithin-cholesterol acyltransferase reaction by oxygen, since congenital absence of the enzyme is associated with anemia. This possibility was explored in eight human subjects who lived in a sealed environmental chamber and breathed 100% oxygen at 258 mm Hg pressure for 30 days. In their plasma a 40% decrease in the conversion of free cholesterol to ester was demonstrated in vitro after four weeks’ exposure to 100% oxygen. Plasma cholesteryl ester concentration was also decreased. Red blood cell mass was reduced and erythropoiesis was depressed. These findings support the hypothesis that the anemia induced by exposure to 100% oxygen was caused in part by decreased synthesis of cholesteryl esters secondary to an inhibition of the plasma lecithin-cholesterol acyltransferase reaction.     

Network monitoring for energy efficiency in large-scale networks: the case of the Spanish Academic Network

The energy consumption due to information technologies is large and there are many ongoing efforts to cut it down. Previous studies have shown that there is a significant percentage of hosts which are left switched on in office buildings at night and weekend, whose energy consumption is significant. This motivates the development of techniques that can detect switched-on hosts in a simple and scalable way. This paper proposes detection techniques based on network traffic monitoring. The results show that such techniques can effectively detect switched-on hosts in small-medium campus networks and also in large country-wide networks that serve more than one million users. Interestingly, the proposed techniques can be implemented using the existing network monitoring infrastructure, specially for large networks, at a negligible additional investment.     

DRCW-OVO: Distance-based relative competence weighting combination for One-vs-One strategy in multi-class problems

One-vs-One strategy is a common and established technique in Machine Learning to deal with multi-class classification problems. It consists of dividing the original multi-class problem into easier-to-solve binary subproblems considering each possible pair of classes. Since several classifiers are learned, their combination becomes crucial in order to predict the class of new instances. Due to the division procedure a series of difficulties emerge at this stage, such as the non-competence problem. Each classifier is learned using only the instances of its corresponding pair of classes, and hence, it is not competent to classify instances belonging to the rest of the classes; nevertheless, at classification time all the outputs of the classifiers are taken into account because the competence cannot be known a priori (the classification problem would be solved). On this account, we develop a distance-based combination strategy, which weights the competence of the outputs of the base classifiers depending on the closeness of the query instance to each one of the classes. Our aim is to reduce the effect of the non-competent classifiers, enhancing the results obtained by the state-of-the-art combinations for One-vs-One strategy. We carry out a thorough experimental study, supported by the proper statistical analysis, showing that the results obtained by the proposed method outperform, both in terms of accuracy and kappa measures, the previous combinations for One-vs-One strategy.     

HTML5-based system for interoperable 3D digital home applications

Digital home application market shifts just about every month. This means risk for developers struggling to adapt their applications to several platforms and marketplaces while changing how people experience and use their TVs, smartphones and tablets. New ubiquitous and context-aware experiences through interactive 3D applications on these devices engage users to interact with virtual applications with complex 3D scenes. Interactive 3D applications are boosted by emerging standards such as HTML5 and WebGL removing limitations, and transforming the Web into a real application framework to tackle interoperability over the heterogeneous digital home platforms. Developers can apply their knowledge of web-based solutions to design digital home applications, removing learning curve barriers related to platform-specific APIs. However, constraints to render complex 3D environments are still present especially in home media devices. This paper provides a state-of-the-art survey of current capabilities and limitations of the digital home devices and describes a latency-driven system design based on hybrid remote and local rendering architecture, enhancing the interactive experience of 3D graphics on these thin devices. It supports interactive navigation of high complexity 3D scenes while provides an interoperable solution that can be deployed over the wide digital home device landscape.     

Electric-field control of local ferromagnetism using a magnetoelectric multiferroic

Multiferroics are of interest for memory and logic device applications, as the coupling between ferroelectric and magnetic properties enables the dynamic interaction between these order parameters. Here, we report an approach to control and switch local ferromagnetism with an electric field using multiferroics. We use two types of electromagnetic coupling phenomenon that are manifested in heterostructures consisting of a ferromagnet in intimate contact with the multiferroic BiFeO(3). The first is an internal, magnetoelectric coupling between antiferromagnetism and ferroelectricity in the BiFeO(3) film that leads to electric-field control of the antiferromagnetic order. The second is based on exchange interactions at the interface between a ferromagnet (Co(0.9)Fe(0.1)) and the antiferromagnet. We have discovered a one-to-one mapping of the ferroelectric and ferromagnetic domains, mediated by the colinear coupling between the magnetization in the ferromagnet and the projection of the antiferromagnetic order in the multiferroic. Our preliminary experiments reveal the possibility to locally control ferromagnetism with an electric field.     

Clinical Parameters and Epigenetic Biomarkers of Plaque Vulnerability in Patients with Carotid Stenosis

Atheromatous disease is the first cause of death and dependency in developed countries and carotid artery atherosclerosis is one of the main causes of severe ischaemic strokes. Current management strategies are mainly based on the degree of stenosis and patient selection has limited accuracy. This information could be complemented by the identification of biomarkers of plaque vulnerability, which would permit patients at greater and lesser risk of stroke to be distinguished, thus enabling a better selection of patients for surgical or intensive medical treatment. Although several circulating protein-based biomarkers with significance for both the diagnosis of carotid artery disease and its prognosis have been identified, at present, none have been clinically implemented. This review focuses especially on the most relevant clinical parameters to take into account in routine clinical practice and summarises the most up-to-date data on epigenetic biomarkers of carotid atherosclerosis and plaque vulnerability.     

Effect of lyophilized water extracts of Melissa officinalis on the stability of algae and linseed oil-in-water emulsion to be used as a functional ingredient in meat products

Previous work pointed out the possibility to enhance the nutritional value of meat products using long chain ω − 3 PUFA enriched emulsions. Oil-in-water emulsions elaborated with a mixture of algae and linseed oils (15:10) in order to be used as functional ingredient were stabilized with BHA (butylhydroxyanisol) or with a lyophilized water extract of Melissa officinalis L. (Lemon balm). The lipid profile of the oil mixture showed a high amount of DHA (31.7%), oleic (25.4%) and α-linolenic acid (12.7%) resulting in a very low ω − 6/ω − 3 ratio (0.12). The lyophilized extract of M. officinalis showed a high antioxidant activity (being 62 ppm of the lyophilized water extract of Melissa equivalent to 200 ppm of BHA, using the DPPH assay as reference), and high total phenolic content. Studying the oxidation process in the emulsions during 15 days at room temperature, it could be concluded that this extract was as efficient as BHA in order to control the thiobarbituric acid reactive substances (TBARS) formation.     

Variations in volatile compounds and flavour in Idiazabal cheese manufactured from ewe's milk in farmhouse and factory

Stage of lactation, use of bulk milk or milk from individual flocks, and cheese‐making in farmhouse or industrial factory are important factors affecting the production and quality of Idiazabal cheese. The volatile composition of cheese samples made from raw ewe's milk in farmhouses or industrial plants at two different times of the year and aged for 90 and 180 days was analysed by dynamic headspace coupled to GC‐MS. Short‐chain fatty acids, primary and secondary alcohols, methyl ketones and ethyl esters were the most abundant compounds in the aroma of Idiazabal cheese samples. Differences in the volatile composition were found between farmhouse and industrial cheeses made at different times of the year and ripened for 90 or 180 days. Likewise, the sensory profiles of the farmhouse and industrial cheeses were significantly different, regardless of the time of the year and ripening time. The results for the principal component analysis (PCA) performed on the sensory attributes of the cheese samples showed two PCs defined as ‘farmhouse flavour factor’ and ‘industrial flavour factor’. Farmhouse cheeses showed high scores for buttery, milky and toasty odours, and buttery and nutty flavours, whereas industrial cheeses showed high scores for sharp, rennet and brine odours, and rennet and rancid flavours. The percentages of methyl ketones such as 3‐hydroxy‐2‐butanone, 2‐butanone, 2‐pentanone and 2‐heptanone, and acids such as n‐propanoic, 2‐methylpropanoic and 3‐methylbutanoic acids were higher in farmhouse cheeses than in industrial cheeses. On the other hand, the percentages of esters such as ethyl butanoate and ethyl hexanoate, and alcohols such as 3‐methyl‐1‐butanol, and acids like n‐hexanoic acid were higher in industrial cheeses than in farmhouse cheeses. Relationships between sensory attributes and volatile compounds were studied on the basis of the differences found in sensory profile and volatile composition between farmhouse and industrial cheeses. Copyright © 2005 Society of Chemical Industry