Reliability analysis for systems with large hydro resources in a deregulated electric power market

This work describes a procedure that determines the optimal allocation for the yearly energy resulting from random water inflows to the different subperiods of a year so that the expected benefits are maximized. Its main idea is to distribute the energy stored in reservoirs in each period into two parts: one is directly sold in the energy market, while the other is made available to cover any unplanned outages of thermal units. The method proposed fulfills two objectives, to distribute the hydro energy optimally according to economic criteria and to assess the impact of new market rules on the reliability of an electric system. The procedure will be illustrated by an example based on the Spanish generating system.     

Inhibition of phospholipase D activity by fodrin. An active role for the cytoskeleton

Phospholipase D (PLD) is a major enzyme implicated in important cellular processes such as secretion and proliferation. The knowledge of its regulation is essential to understand the control of these phenomena. Several proteins activating PLD have been described in the last years. In this report, we chromatographed bovine brain cytosolic proteins to identify fodrin, the non-erythroid spectrin, as the first described inhibitor of PLD. A cytosolic fraction with an inhibitory effect on PLD activity loses its capacity after immunoprecipitation of fodrin. Moreover, at 1 nM, purified fodrin blocks fully and quickly PLD activity, whatever the stimuli used. In contrast, fodrin has no effect on adenylate cyclase activity. Fodrin-analogous proteins like dimeric or tetrameric erythroid spectrin have the same inhibitory effect on PLD, at higher concentrations. Other cytoskeletal proteins, actin and vimentin, are inefficient on PLD inhibition. The mechanisms implicated in PLD modulation such as post-translational modifications of fodrin and the role of small G-proteins on the cytoskeleton regulation are discussed. In conclusion, this study reveals that fodrin is involved in the control of PLD activity, suggesting that the cytoskeleton could have an active role in control of secretion and proliferation.     

The perceived quality of hospital care

For the functional psychoses of late life, epidemiological information comes from two sources: studies of persons who have reached psychiatric services; and surveys of elderly persons sampled from the general population. A conspectus of published data from both sources leads to the following conclusions: States phenomenologically similar to those found in clinics do occur in the community in non-trivial numbers. There is no notable divergence in the information obtained from clinical series and from population-based surveys. These states are more common in women, they become more common with increasing age and are sometimes associated with decline in cognitive performance or with degenerative changes in the brain revealed by neuroimaging. Genetic factors appear to be less important than in early-onset psychoses but remain ill-defined, and the roles of social isolation and disorders of personality have not yet been sufficiently elucidated. Both clinical and community-based studies have found an association with sensory impairment. The community-based data suggest that paranoid symptoms may be detectable at subclinical level, and an association between them and cognitive impairment is demonstrable in individuals who are not diagnosable cases either of psychosis or of dementia. Differences exist between late-onset paranoid psychoses and affective psychoses in symptomatology and response to treatment. These observations confirm the importance of the late-onset psychoses for research directed towards uncovering the origins of psychotic symptoms in any age group.     

How Individuals Explain Social Problems: The Influences of Media Use

This study examined the role of media use in individuals' explanations of crime and welfare. Attribution theory and the information-processing approach to media effects provided a theoretical framework for this research. Media effects on explanations of social problems are enhanced by individuals' patterns of information processing. Specifically, active processing of national television public affairs content increased while active processing of newspaper public affairs content decreased the likelihood of individualistic explanations. The study also showed that individualistic explanations of crime and welfare are related to support for the death penalty and to opposition toward welfare programs.     

Polar pollutants entry into the water cycle by municipal wastewater: a European perspective

The effluents of eight municipal wastewater treatment plants (WWTP) in Western Europe were analyzed by liquid-chromatography-mass spectrometry for the occurrence of 36 polar pollutants, comprising household and industrial chemicals, pharmaceuticals, and personal care products. In a long-term study of the effluents of three WWTP over 10 months, sulfophenyl carboxylates and ethylene diamino tetraacetate (EDTA) were detected above 10 microg/L on average, while benzotriazoles, benzothiazole-2-sulfonate, diclofenac, and carbamazepine showed mean concentrations of 1-10 microg/L, followed by some flame retardants, naphthalene disulfonates, and personal care products in the range of 0.1-1 microg/L. Half of the determined compounds were not significantly removed in tertiary wastewater treatment. By dividing the effluent concentration of a compound by its relative removal in WWTP a water cycle spreading index (WCSI) was calculated for each compound. We propose that this index provides a measure for the potential of a polar compound to spread along a partially closed water cycle after discharge with municipal wastewater and to occur in raw waters used for drinking water production. Polar pollutants in surface water samples of different catchments showed increasing concentration for compounds with increasing WCSI.     

Correspondence analysis approach for finding allele associations in population genetic study

In population genetic study, one of the first analyses is to explore the relationships among the frequencies of alleles within or between loci. Hardy-Weinberg equilibrium is tested for two alleles of a single locus, and the linkage disequilibrium is tested for an allele from each of two loci. Although the equilibrium plays an important role and often serves as a basis for genetic inference, research on the graphical representation of this information is rare. In this study, we consider correspondence analysis and biplot approaches as tools for finding associations between alleles. We also propose the supplementary data method to compare allele frequencies of several populations from different studies. These approaches provide the graphical representation which makes it easy to interpret the patterns of disequilibrium and to compare the allele frequencies between populations. These proposed methods are illustrated with numerical examples.     

On the Benefits of Adaptivity in Property Testing of Dense Graphs

We consider the question of whether adaptivity can improve the complexity of property testing algorithms in the dense graphs model. It is known that there can be at most a quadratic gap between adaptive and non-adaptive testers in this model, but it was not known whether any gap indeed exists. In this work we reveal such a gap.