Power Indices

This article reviews some of the basic institutional elements and empirical regularities of the U.S. electoral college system. Historical election results confirm the expected dominance of the winner-takeall allocation of electors within each state. Of greater interest is the array of state preferences for the electoral college given a national popular vote as the contemplated alternative. It is necessary to be clear about what is meant by a state’s preference. The concept explored here is sometimes referred to as a state’s a priori preference. A state prefers a priori the system that results in the greater potential influence of its voters, as represented by the state’s popular-vote majority, on the outcome of an election. In this context the term “a priori” means in consideration of only the system itself, without (a posteriori) considerations of actual or likely outcomes in particular elections (see Felsenthal and Machover 2004.) In addition, as discussed below, a state can be sa...

Terms of address in Shona derive from a multiplicity of sources, both modern and traditional. Proper names, nicknames, titles, pronouns and prefixes are commonly used. Emphasis is on the discussion of the type of names the Shona Utilize, the contexts in which they are applied, their semantics and the circumstances that motivate their creation. The speaker and the addressee's relationship, cognitive, historical and ideological reality, determine the choice of names and other address variants. The choices also reflect very broad categories of social meaning. Address forms can, therefore, be screens upon which the Shona project their attitudes towards different aspects of their life. The author shows that the use of address forms and cultural values are closely interrelated. This article gives a socio-linguistic account of the synchronic patterns and diachronic change in address terms. Shifts over time in addressing patterns may provide a powerful indicator of profound societal shifts.

The high success rate of Commission proposals seems to suggest that the European Commission is very influential in promoting European policies. However, the Commission's agenda-setting activity might be affected by its anticipation of member states' preferences. If the Commission acts with foresight, it simply does not initiate a proposal when it knows that the proposal will not be acceptable to member state governments in the Council or, more recently, the European Parliament. In this respect, the Commission is far less powerful than it appears. We test this hypothesis with aggregate data on the number of Commission proposals for directives and the degree of EU support in the Council between 1976 and 2003. The results of the analysis broadly support the theoretical argument.

A parametric study to clarify efficiency limiting mechanisms and to maximize the performance of the CH 2 F 2 laser has led to the discovery of five new CO 2 pump lines and ten new FIR laser lines. The wavelengths of the new lines fill a previous gap in the spectrum of strong cw FIR laser lines. With appropriate cavity design, measured conversion efficiencies exceed 30% of the maximum theoretical limit. Optimization of the output coupling for the strongest line at X = 184.6 ,m has doubled the maximum output power from the identical system using the X = 118.8-,um line of CH 3 0H. The exceptionally high conversion efficiency (33%) occurring at the highest-available CO 2 pump power indicates that the limits on scaling to higher output powers have not yet been reached. The results confirm the high-performance capability of the CH 2 F 2 laser, the strongest cw optically pumped FIR laser reported to date. Efficient FIR lasing has recently been reported from the cw optically pumped CH 2 F 2 molecule.' The fortunate combination of strong absorption of the CO 2 pump radiation and rapid collisionally dominated vibrational relaxation in CH 2 F 2 produced a factor-of-2 improvement in conversion efficiency over the best previously reported optically pumped cw FIR lasers. Continued efforts have shown that these benefits are largely a consequence of the molecular dynamics, which permit nondiffusion-limited operation of the CH 2 F 2 laser. 2 This Letter summarizes further parametric investigation to maximize the performance of the CH 2 F 2 laser. The discovery of five new CO 2 pump lines, which produce ten new FIR laser lines, is also reported. The wavelengths of these new lines are important not only because of their strength but also because they fall in the region between the strong X = 118.8-Mm line of CH 3 0H and the X = 393.6-Am line of HCOOH, where previously a gap existed in the spectrum of strong cw FIR laser transitions. The ekperimental setup was the same one used to achieve efficient high-power operation with CH 3 0H and CH 3 F. Briefly, it consisted of a FIR waveguide resonator pumped by a grating-tuned C0 2 laser with an average output power up to 30 W on the strongest 9-pm CO 2 line. The discharge current of the CO 2 laser is modulated using a voltage-controlled current regulator at 500 Hz, producing a 50% duty-cycle square-wave modulation. The 2-msec duration of the CO 2 pulses is

Both physical and mental effort are thought to affect vigilance. Mental effort is known for its vigilance declining effects, but the effects of physical effort are less clear. This study investigated whether these two forms of effort affect the EEG and subjective alertness differently. Participants performed a physical task and were subsequently presented with a mental task, or vice versa. Mental effort decreased subjective alertness and increased theta power in the EEG. Both results suggest a vigilance decline. Physical effort, however, increased subjective alertness and alpha and beta1 power in the EEG. These findings point towards an increase in vigilance. Beta2 power was reduced after physical effort, which may reflect a decrease in active cognitive processing. No transfer effects were found between the effort conditions, suggesting that the effects of mental and physical effort are distinct. It is concluded that mental effort decreases vigilance, whereas physical effort increases vigilance without improving subsequent task performance.

In the present paper, we consider a nonlinear fractional snap model with respect to a G-Caputo derivative and subject to non-periodic boundary conditions. Some qualitative analysis of the solution, such as existence and uniqueness, are investigated in view of fixed-point theorems. Moreover, the stabilities of Ulam-Hyers and Ulam-Hyers-Rassias criterions are considered and investigated. Some numerical simulations were performed using MATLAB for understanding the theoretical results. All results in this work play an important role in understanding ocean engineering phenomena due to the huge applicability of jerk and snap in seakeeping, ride comfort, and shock response spectrum.

Power and Fairness'' in Bad Segeberg, at the 4th Hamburg Workshop in Game Theory and Applications in Hamburg, Public Choice Society Meetings in San Antonio, European Public Choice Society Meeting in Paris and at Italian Meeting of Game Theory and Applications in Ischia. The authors thank Manfred Holler, Roland Kirstein, the participants of above-mentioned meetings, and two anonymous referees for valuable comments and suggestions.

A set o f new power indices is introduced extending Banzhaf power index and allowing us to take into account agents' preferences to coalesce. An axiomatic characterization of intensity functions representing a desire of agents to coalesce is given. A set of axioms for new power indices is presented and discussed. An example of use of these indices for Russian parliament is given.

To evaluate the prognostic impact of minimal residual disease (MRD), quantitative real-time polymerase chain reaction (RQ-PCR) of clonal IGH rearrangements was performed in 29 patients with mantle cell lymphoma (MCL) treated with high-dose radiochemotherapy and autologous stem cell transplantation (ASCT). Fourteen of 27 patients evaluable for MRD after ASCT achieved complete clinical and molecular remission, whereas 13 patients had detectable MRD within the first year after ASCT. Molecular remission after ASCT was strongly predictive for improved outcome, with a median progression-free survival (PFS) of 92 months in the MRD-negative group compared with 21 months in the MRD-positive group (P < .001). Median overall survival (OS) was 44 months in the MRD-positive group and has not been reached in the MRD-negative group (P < .003). In multivariate analysis, molecular remission and bulky disease were independent prognostic factors for PFS (P = .001 and P = .021, respectively). Whi...

Rationale Typical users of 3,4-methylenedioxymethamphetamine (MDMA or "ecstasy") are polydrug users, combining MDMA with alcohol or cannabis [most active compound: delta-9-tetrahydrocannabinol (THC)]. Objectives The aim of the present study was to investigate whether co-administration of alcohol or THC with MDMA differentially affects ongoing electroencephalogram (EEG) oscillations compared to the administration of each drug alone. Methods In two separate experiments, 16 volunteers received four different drug conditions: (1) MDMA (100 mg); (2) alcohol clamp (blood alcohol concentration=0.6‰) or THC (inhalation of 4, 6 and 6 mg, interval of 1.5 h); (3) MDMA in combination with alcohol or THC; and (4) placebo. Before and after drug administration, electroencephalography was recorded during an eyes closed resting state. Results Theta and alpha power increased after alcohol intake compared to placebo and reduced after MDMA intake. No interaction between alcohol and MDMA was found. Significant MDMA × THC effects for theta and lower-1-alpha power indicated that the power attenuation after the combined intake of MDMA and THC was less than the sum of each drug alone. For the lower-2-alpha band, the intake of MDMA or THC alone did not significantly affect power, but the intake of combined MDMA and THC significantly decreased lower-2-alpha power. Conclusions The present findings indicate that the combined intake of MDMA and THC, but not of MDMA and alcohol, affects ongoing EEG oscillations differently than the sum of either one drug alone. Changes in ongoing EEG oscillations may be related to the impaired task performance that has often been reported after drug intake.

Rationale Typical users of 3,4-methylenedioxymethamphetamine (MDMA or "ecstasy") are polydrug users, combining MDMA with alcohol or cannabis [most active compound: delta-9-tetrahydrocannabinol (THC)]. Objectives The aim of the present study was to investigate whether co-administration of alcohol or THC with MDMA differentially affects ongoing electroencephalogram (EEG) oscillations compared to the administration of each drug alone. Methods In two separate experiments, 16 volunteers received four different drug conditions: (1) MDMA (100 mg); (2) alcohol clamp (blood alcohol concentration=0.6‰) or THC (inhalation of 4, 6 and 6 mg, interval of 1.5 h); (3) MDMA in combination with alcohol or THC; and (4) placebo. Before and after drug administration, electroencephalography was recorded during an eyes closed resting state. Results Theta and alpha power increased after alcohol intake compared to placebo and reduced after MDMA intake. No interaction between alcohol and MDMA was found. Significant MDMA × THC effects for theta and lower-1-alpha power indicated that the power attenuation after the combined intake of MDMA and THC was less than the sum of each drug alone. For the lower-2-alpha band, the intake of MDMA or THC alone did not significantly affect power, but the intake of combined MDMA and THC significantly decreased lower-2-alpha power. Conclusions The present findings indicate that the combined intake of MDMA and THC, but not of MDMA and alcohol, affects ongoing EEG oscillations differently than the sum of either one drug alone. Changes in ongoing EEG oscillations may be related to the impaired task performance that has often been reported after drug intake.

A well known and established model in communication policy in sociology and marketing is that of opinion leadership. Opinion leaders are actors in a society who are able to affect the behavior of other members of the society called followers. Hence, opinion leaders might have a considerable impact on the behavior of markets and other social agglomerations being made up of individual actors choosing among a number of alternatives. For marketing or policy purposes it appears to be interesting to investigate the effect of different opinion leader-follower structures in markets or any other collective decision-making situations in a society. We study a two-action model in which the members of a society are to choose one action, for instance, to buy or not to buy a certain joint product, or to vote yes or no on a specific proposal. Each of the actors has an inclination to choose one of the actions. By definition opinion leaders have some power over their followers, and they exercise this power by influencing the behavior of their followers, i.e. their choice of action. After all actors have chosen their actions, a decision-making mechanism determines the collective choice resulting out of the individual choices. Making use of bipartite digraphs we introduce novel satisfaction and power scores which allow us to analyze the actors' satisfaction and power with respect to the collective choice for societies with different opinion leader-follower structures. Moreover, we study common dictator and opinion leader properties of the above scores and illustrate our findings for a society with five members.

A set of agents arrive simultaneously to a service facility. Each agent requires the facility for a certain length of time and incurs a cost for each unit of time spent in queue. Attached to each agent is an index, which is the ratio of her waiting cost rate to processing time. Eciency dictates that the agents be served in decreasing order of their indices. If monetary compensations are disallowed, fairness suggests that agents be served in a random order, each ordering of the agents being equally likely. The ecien t ordering is unfair to agents with low indices; the random service order is typically extremely inecien t. It is well-known that this gap can be bridged by using monetary compensations. This paper is motivated by the need to design compensation schemes that are fair to all the agents. To that end, we propose two solution concepts (RP and CRP cores), which serve to place upper bounds on the cost share of any coalition of agents. The solutions dier in the denition of the e...

A set of agents arrive simultaneously to a service facility. Each agent requires the facility for a certain length of time and incurs a cost for each unit of time spent in queue. Attached to each agent is an index, which is the ratio of her waiting cost rate to processing time. Efficiency dictates that the agents be served in decreasing order of their indices. If monetary compensations are disallowed, fairness suggests that agents be served in a random order, each ordering of the agents being equally likely. The efficient ordering is unfair to agents with low indices; the random service order is typically extremely inefficient. It is well-known that this gap can be bridged by using monetary compensations. This paper is motivated by the need to design compensation schemes that are fair to all the agents. To that end, we propose two solution concepts (RP and CRP cores), which serve to place upper bounds on the cost share of any coalition of agents. The solutions differ in the definition of the expected worth of a coalition, when the agents are served in a random order. A detailed study of these two concepts as well as their compatibility with other fairness criteria (such as the LB core, due to Maniquet) are the main focus of this paper. We show that the RP core may be empty; but the CRP core is always nonempty, is compatible with the LB core, and contains the equal gains solution. Moreover, we provide an efficient algorithm to find the the egalitarian solution proposed by Dutta and Ray , which equalizes costs among all core solutions. We also explore two natural special-cases: identical waiting cost rates and identical processing times. When the waiting cost rates are identical, we prove that the RP core is nonempty, compatible with the LB core, and in fact contains both the equal gains solution and the equal costs. For the case of identical processing times, we show that the RP core is nonempty and contains all envy-free solutions, but is, in general, incompatible with the LB core.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative treatment option for patients with acute lymphoblastic leukemia (ALL). The curative potential of allo-HSCT for ALL is, in part, due to the graft-vs.-leukemia (GVL) effect, in addition to the intensive conditioning chemo-radiotherapy. However, relapse remains the major cause of treatment failure following allo-HSCT for ALL. In the allo-HSCT setting, testing for genetic markers of hematopoietic chimerism has become a part of the routine diagnostic program. Routine chimerism analysis is usually performed in peripheral blood or bone marrow; in fact, little is known about the value of tissue chimerism in patients with extramedullary relapse (EMR) after the allo-HSCT setting. The present study reports on, a case of a patient with ALL who experienced isolated cutaneous EMR despite ongoing graft-vs.-host disease (GVHD), and the results of peripheral blood and skin tissue chimerism studies using multiplex polymerase chain reaction (PCR) of short tandem repeats (STR-PCR). The present case demonstrates that, although complete remission and/or chimerism may be achieved in the bone marrow, chimerism achieved at the tissue level, and the subsequent GVL effect, may be limited, despite concomitant severe GVHD following allo-HSCT. Our tissue chimerism analysis results provide a good example of how skin tissue may be a 'sanctuary' site for effector cells of GVL, despite active GVHD and complete hematopoetic chimerism.

With global climate changes, biological invasions are considered to be one of the main causes of the decline of freshwater biodiversity. In this context, predicted increases in global temperature may alter the geographical distributions of native and invasive species. The purpose of our study was to examine the metabolic, behavioral and physiological responses to short-term temperature acclimation of two widely distributed species (the most successful European invader, Dikerogammarus villosus, and its main victim, Gammarus pulex), in order to estimate the potential effect of global warming on its invasion of freshwater ecosystems. Our results show that D. villosus is more vulnerable to high temperatures than G. pulex. The native species seems to be best adapted to intermediate temperatures (10-20 °C) with a possibility of adjustment to "extreme" temperatures (5-27 °C), whereas the "killer shrimp" D. villosus seems best adapted to lower temperatures (5-10 °C) with a limited possibility of adjustment above 20 °C. In the light of our results, global warming is likely to be less favorable to the invasive species. However, D. villosus showed reduced metabolic and activity rates, associated with higher glycogen content. This adaptive strategy was interpreted as having functional advantages, allowing D. villosus to successfully invade harsh and/or unpredictable biotopes. In addition, our results show that glycogen stores may be used as a powerful indicator of the optimal thermal window for aquatic ectotherms.

Resorting to political economy approaches, this paper attempts to associate the industrial structure in the European Union (EU) to the coalition formation process between European member states. Using a well-known measure of relative voting power, the (normalized) Banzhaf power index, we relax the common assumption that coalitions form randomly. Instead, we adopt the standard interest group model and look at the structure of European industry, mainly in terms of industrial concentration in the EU, as an indicator of its lobbying influence on domestic politics and governments' preferences. This, in turn, influences the political stance, and thus the coalition building process, of the different member states in the Council. We derive estimates on members' relative influence within the Council for different policy areas in the broader framework of industry and trade, on the basis of both weighted votes and likely patterns of coalition-formation in the Council. p We are grateful to Gerrit Faber, Christine Neuhold, Phedon Nicolaides, Marcelo Olarreaga, and participants at the Biannual Meeting of the European Community Studies Association (ECSA) in Pittsburgh, 2-5 June 1999, where an earlier version of this paper was presented, for their helpful comments.

Nest predation has been identified as the primary mechanism contributing to reduction of reproductive success for the marsh-breeding red-winged blackbird (Agelaius phoeniceus). Differences in rates of nest predation have been linked to nest site characteristics within a wetland, primarily water depth. However, the relationship between the landscape surrounding these habitats and the probability of nest predation is uncertain. Moreover, factors associated with reproductive success could be a potentially powerful indicator of ecological condition in wetland habitats. We investigated the influence of landscape pattern on nest success by monitoring 366 red-winged blackbird nests in 11 coastal wetlands along the south shore of Lake Superior. Of the 366 nests, 39% were successful, 56% failed, and 5% were abandoned or lacked sufficient evidence to determine nest fate. Nest predation accounted for over 93% of total failures. Predation rates ranged from 31% to 97% among the 11 wetland sites. We modeled nest predation using multi-model logistic regression analysis and the Akaike information criterion to identify and parameterize influential variables derived from the nest site, wetland, and landscape surrounding each wetland. Our results indicated that landscape variables comprised over 50% of model prediction weight in 15 of the 17 models. Nest failure was highest at sites within an urban/residential landscape matrix. Reproductive success could be a good indicator of the ecological health of Great Lakes wetlands.

Submergent aquatic vegetation (SAV) is a powerful indicator of environmental conditions in both marine and fresh water ecosystems. Quickbird imagery was used to map SAV at three sites across the Great Lakes. Unsupervised classifications were performed at each site using summer Quickbird sensor data. At one site, a multi-temporal classification approach was added, combining visible red difference (May-August) with August red and green visible band data. Multi-temporal SAV classification was superior to single-date results at this site. Muck bottom was not seriously confused with SAV, which was unexpected. Multi-temporal classification results showed less confusion between deep water and SAV, although spectral variability due to sub-surface sandbar structure was a source of error in both single-and multi-date classifications. Nevertheless, some of the confounding effects of water column on SAV classification appear to have been mitigated using this multi-temporal approach. Future efforts would be well served by incorporating detailed, continuous, bathymetry data in the classification process. Quickbird sensor data are very useful for classifying SAV under US Great Lakes conditions. However, regional classification efforts using these data may be impractical at this time, as high cost, rigid tasking parameters and unpredictable water conditions limit availability of suitable imagery.

A well known and established model in communication policy in sociology and marketing is that of opinion leadership. Opinion leaders are actors in a society who are able to affect the behavior of other members of the society called followers. Hence, opinion leaders might have a considerable impact on the behavior of markets and other social agglomerations being made up of individual actors choosing among a number of alternatives. For marketing or policy purposes it appears to be interesting to investigate the effect of different opinion leader-follower structures in markets or any other collective decision-making situations in a society. We study a two-action model in which the members of a society are to choose one action, for instance, to buy or not to buy a certain joint product, or to vote yes or no on a specific proposal. Each of the actors has an inclination to choose one of the actions. By definition opinion leaders have some power over their followers, and they exercise this power by influencing the behavior of their followers, i.e. their choice of action. After all actors have chosen their actions, a decision-making mechanism determines the collective choice resulting out of the individual choices. Making use of bipartite digraphs we introduce novel satisfaction and power scores which allow us to analyze the actors' satisfaction and power with respect to the collective choice for societies with different opinion leader-follower structures. Moreover, we study common dictator and opinion leader properties of the above scores and illustrate our findings for a society with five members.

A set of new power indices is introduced extending Banzhaf power index and allowing to take into account agents' preferences to coalesce. An axiomatic characterization of intensity functions representing a desire of agents to coalesce is given. A set of axioms for new power indices is presented and discussed. An example of use of these indices for Russian parliament is given.

This paper is devoted to the concept of indirect control in corporate shareholding networks. This topic is important in financial economics. Since shareholding size does not actually reflect an investor's power-control in corporate shareholding networks, diverse approaches to measuring the control-power of investors has been proposed. We focus in particular on a game-theoretical approach; specifically the model of Denti and Prati (2001) and its implementation to control sharing analysis and simulation in shareholding networks thanks to the computer program "Control Sharing Simulation".

FLAVIO TONELLI Department of Production Engineering, Thermo energetic, and Mathematical Models University of Genoa Via All'Opera Pia 15, 16145 Genoa ITALY flavio.tonelli@diptem.unige .it ... ROBERTO REVETRIA Department of Production Engineering, Thermo energetic, ...

In mathematics, monotonicity is used to denote the nature of the connection between variables. Hence for example, a variable is said to be a monotonically increasing function of another variable if an increase in the value of the latter is always associated with an increase in the other variable. In the theory of voting and the measurement of a priori voting power one encounters, not one, but several concepts that are closely related to the mathematical notion of monotonicity. We deal with such notions focusing particularly on their role in capturing key aspects of plausible opinion aggregation. Further, we outline approaches to analyzing the relationship of opinion aggregation and voting power and thereby contribute to our understanding of major components that determine the outcome of voting.

Starting from Max Weber's definitions of power we discuss the meaning of his concept Chance and its relationships to the probabilistic notions that play a central role in definitions of indices of measuring voting power. Using Martin Hollis's distinction between two models of man-plastic and autonomous-we argue that the common measures of voting power when interpreted in terms of probabilities seem to be in better conformity with the model of plastic man than with the model of autonomous man. The paper elaborates on the probability interpretation with applications to the modelling of power measures with a priori unions and to the concept of "real voting power" based on relative frequencies of historical events. Power as potential-which in our view is what Weber very likely meant-remains an elusive concept, but one that should be amenable to game-theoretic analysis.

Multiterawatt hybrid GARPUN-MTW laser is described being developed under Petawatt Excimer Laser Project at P.N. Lebedev Physical Institute as a test bench facility for verification the challenge of KrF laser as a driver in the fast-ignition concept of Inertial Confinement Fusion. It implements direct amplification of ultra-high intensity subpicosecond UV laser pulses alone or on a par with nanosecond pulses in a multi-stage e-beampumped 100-J, 100-ns GARPUN KrF laser facility. Ti:Sapphire front-end “Start 248M” operates with a rep rate 0-10 Hz, pulse energy and duration at fundamental wavelength (744 nm) > 8 mJ and < 60 fs, at 3ω (248 nm) > 0.5 mJ and < 65 fs. It consists of Kerr lens mode-locked master oscillator (<30 fs, 80 МHz, 150 mW, wavelength centered at 740 nm) pumped by 2ω diode-pumped CW Finesse 4W Nd:YAG laser (3.5 W, 532 nm), all reflective-optics pulse stretcher up to 200 ps, regenerative amplifier (10 Hz, > 0.4 mJ, 740 nm) and multi-pass amplifier (10...

Assessing the voting power of a decision maker depends on the appropriate evaluation of all factors influencing such power. Models constructed with the use of a set of given factors are usually statistically significant, but at the same time the determination coefficient is very low. An econometric technique is proposed, which increases the determination coefficient of such a model and consequently improves the estimation of voting power using a power index. Such an approach enables us to investigate the nature of hidden factors by considering their effects and variation in the model. An example and algorithm for improving the econometric model are also presented.

Assessing the voting power of a decision maker depends on the appropriate evaluation of all factors influencing such power. Models constructed with the use of a set of given factors are usually statistically significant, but at the same time the determination coefficient is very low. An econometric technique is proposed, which increases the determination coefficient of such a model and consequently improves the estimation of voting power using a power index. Such an approach enables us to investigate the nature of hidden factors by considering their effects and variation in the model. An example and algorithm for improving the econometric model are also presented.

Classical power analysis does not involve preferences of players (parties). Classical power indices are constructed under assumption of equal probability of occurrence for each coalition. The paper contains a proposition of relaxation of this assumption, based on extended Shapley-Shubik power index approach.

Downloadable! Shapley-Shubik and Penrose-Banzhaf (absolute and relative) power measures and their interpretations are analysed. Both of them could be successfully derived as cooperative game values, and at the same time both of them can be interpreted as probabilities of ...

A set of new power indices is introduced extending Banzhaf power index and allowing to take into account agents' preferences to coalesce. An axiomatic characterization of intensity functions representing a desire of agents to coalesce is given. A set of axioms for new power indices is presented and discussed. An example of use of these indices for Russian parliament is given.

The Lower Danube, being an important navigable way, is recognized as a heavily modified water body according to the Water Framework Directive criteria. The riparian zone is subjected to various anthropo- genic pressures, such as discharge of organic substances and nutrients, continuity interruption, sediments and gravel abstraction, rip-rap armoring, etc. All of these affect the aquatic communities. The present study represents the distribution of the main macrozoobenthic groups at 16 sites along the Bulgarian stretch of the Danube River, provisionally identified as influenced by different pressures and impacts. The relationship between the longitudinal distribution of macrozoobenthos and the content of some pollutants in both the water and the sediments were studied. Fourteen sampling sites were located downstream major tributaries, cities and harbours and two other were considered as relatively less influenced. The abundance of amphipods, oligochaets and chironomid larvae increase...

IVIE working papers o®er in advance the results of economic research under way in order to encourage a discussion process before sending them to scienti¯c journals for their¯nal publication. * We want to thank M. Maschler and J. M. Zarzuelo for their insightful comments. This research has been supported by the Training and Mobility of Researchers programme initiated by the European Commission, by the IVIE, and by the DGES of the Spanish Ministerio de Educaci ¶ on y Cultura, under project PB96-0247.

Founded in 1963 by two prominent Austrians living in exile-the sociologist Paul F. Lazarsfeld and the economist Oskar Morgenstern-with the financial support from the Ford Foundation, the Austrian Federal Ministry of Education, and the City of Vienna, the Institute for Advanced Studies (IHS) is the first institution for postgraduate education and research in economics and the social sciences in Austria. The Political Science Series presents research done at the Department of Political Science and aims to share "work in progress" before formal publication. It includes papers by the Department's teaching and research staff, visiting professors, graduate students, visiting fellows, and invited participants in seminars, workshops, and conferences. As usual, authors bear full responsibility for the content of their contributions. Das Institut für Höhere Studien (IHS) wurde im Jahr 1963 von zwei prominenten Exilösterreicherndem Soziologen Paul F. Lazarsfeld und dem Ökonomen Oskar Morgenstern-mit Hilfe der Ford-Stiftung, des Österreichischen Bundesministeriums für Unterricht und der Stadt Wien gegründet und ist somit die erste nachuniversitäre Lehr-und Forschungsstätte für die Sozial-und Wirtschaftswissenschaften in Österreich. Die Reihe Politikwissenschaft bietet Einblick in die Forschungsarbeit der Abteilung für Politikwissenschaft und verfolgt das Ziel, abteilungsinterne Diskussionsbeiträge einer breiteren fachinternen Öffentlichkeit zugänglich zu machen. Die inhaltliche Verantwortung für die veröffentlichten Beiträge liegt bei den Autoren und Autorinnen. Gastbeiträge werden als solche gekennzeichnet.

In the recent past, the choice of adequate voting weights and decision rules for the Council of the European Union (EU) has been a highly contested issue in EU intergovernmental negotiations. In general terms, the selection of a threshold for qualified majority votes (QMV) in the Council constitutes a trade-off in terms of decreased sovereignty for individual governments versus an increased collective 'capacity to act'. This paper compares the effects of the proposal tabled by the Convention on the Future of Europe with the Nice Treaty provisions and the Lisbon Treaty, in terms of both the efficiency of decision-making and the distribution of relative voting power within the EU of twenty-seven member states. In addition, the paper shows how with the current size of EU membership, the EU risks being unable to reach intergovernmental agreement. Accordingly, a challenging issue for the future of the EU is to move towards reasonable provisions that allow its own constitution-if ever adopted-to get amended.

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden,

In this paper, we analyze some values and power indices from a different point of view that are well-defined in the social context where the goods are public. In particular, we consider the Public Good index (Holler, 1982), the Public Good value (Holler and Li, 1995), the Public Help index (Bertini et al., 2008), the König and Bräuninger index (1998) also called the Zipke index (Nevison et al., 1978), and the Rae index (1969). The aims of this paper are: to propose an extension of the Public Help index to cooperative games; to introduce a new power index with its extension to a game value; and to provide some characterizations of the new index and values.

INDIRECT CONTROL AND POWER To determine who has the power within a stock corporate company can be a quite complex problem, especially when control is achieved through alliances between shareholders. This problem arises especially in cases of indirect control of corporations, that is, in situations involving shareholders and companies with cross-shareholdings. The first to solve the problem of measuring power in the case of indirect share control were Gianfranco Gambarelli and Guillermo Owen in [10]. In the following years, numerous other models were introduced. In this paper, we critically examine the models of: Gambarelli and Owen, Denti and Prati, Crama and Leruth, Karos and Peters, as well as Mercik and Lobos, taking into account two well-known, illustrative examples, one with an acyclic corporate structure and the other with a cyclic structure.

In this paper we define a new family of solutions for the class of cooperative games with transferable utility, in which the set of players exhibits a structure of a priori unions. This family is deeply connected with the Shapley value for games with transferable utility but, moreover, we assume a solidarity strong connection among all the components of each union. As a consequence of this, they are disposed to delegate one coalition of members of the union to negotiate with the other unions, and, therefore, each union will have a representative coalition. Furthermore, three interesting solutions that belong to this family of values are studied, as well as the non cooperative selection of the best representative coalition for each union.

Johnston (1978), Deegan and Packel (1979), and Holler (1982) proposed three power indices for simple games: Johnston index, Deegan-Packel index, and the Public Good Index. In this paper, methods to compute these indices by means of the multilinear extension of the game are presented. Furthermore, a new characterization of the Public Good Index is given. Our methods are applied to two real-world examples taken from the political field.

We report on a continuous-wave singly resonant optical parametric oscillator (SRO) based on periodically poled KTiOPO 4. This is pumped by a frequency-doubled single-frequency Nd:YAG master oscillator power ampli®er system. Pump wave enhancement allowed for external oscillation thresholds around 200 mW. Up to 72 mW of idler and 28 mW of signal radiation were generated at 1.2 W pump power. Output wavelengths between 865 and 1384 nm were obtained with a single 9 lm period grating by varying the crystal temperature from 37.5°C to 225°C. Mode-hop-free operation of the SRO was demonstrated for up to 69 min.

We report on a green-pumped continuous-wave singly resonant optical parametric oscillator (cw SRO) based on MgO-doped periodically poled LiNbO 3. Operating the SRO at crystal temperatures between 40.0°C to 80.0°C an idler wavelength range of 1406-1451 nm can be accessed. The system provides stable single-frequency idler radiation of more than 300 mW at a pump power of 2 W while featuring a low threshold (<1.2 W). Above a pump power of 2.1 W we observe multimode operation, which is similar to the behavior reported for infrared-pumped SROs. To show the applicability of the device we demonstrate Doppler-free saturation spectroscopy of the cesium D 2 line using the signal wave and frequency stabilization to a crossover resonance of the D 2 transition.

We present a 532 nm-pumped singly-resonant cw optical parametric oscillator based on MgO-doped PPLN with a minimum threshold pump power of 0.3 W. The OPO with a two-mirror standing-wave cavity is optimized by using a tunable diode laser on the path of the resonant signal beam. The maximum output power is 200 mW at an idler wavelength near 1330 nm at a pump power of 2 W. We report the degradation of the output power and beam characteristics at high pump power indicating a strong thermal lensing in the crystal. The continuous tuning range of the OPO is measured to be 800 MHz which is close to 90% of the free spectral range of the OPO cavity.

The paper presents several new approaches to evaluate power distribution in an electoral body. The index of consistency of positions of two groups (briefly, the consistency index) is defined which is used to separate possible coalitions in the Parliament. This allows to analyze power distribution with restricted coalition formation. Then we provide several new power indices for the case when the intensity of factions to coalesce is taken into account. The analysis of power distribution model extends the one proposed by Shapley-Owen is given. A new consistency index is given allowing to construct such extension. We illustrate these approaches via the analysis of power distribution among factions in the Russian Parliament (Duma) from 1993 to 2005.