Measuring Power and Satisfaction in Societies with Opinion Leaders: Dictator and Opinion Leader Properties

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.Bipartite digraph ; influence ; inclination ; collective choice ; opinion leader ; follower ; satisfaction ; power ; dictator properties ; opinion leader properties

Quantum collapses and revivals of a matter wave in the dynamics of symmetry breaking

Using the remarkable mathematical construct of Eugene Wigner to visualize quantum trajectories in phase space, quantum processes can be described in terms of a quasi-probability distribution analogous to the phase space probability distribution of the classical realm. In contrast to the incomplete glimpse of the wave function that is achievable in a single shot experiment, the Wigner distribution, accessible by quantum state tomography, reflects the full quantum state. We show that during the fundamental symmetry-breaking process of a generic quantum system - with a symmetry breaking field driving the quantum system far from equilibrium - the Wigner distribution evolves continuously with the system undergoing a sequence of revivals into the symmetry unbroken state, followed by collapses onto a quasi-classical state akin the one realised in infinite size systems. We show that generically this state is completely delocalised both in momentum and in real space.Comment: 6 pages, 4 figure

Spin-orbital frustrations and anomalous metallic state in iron-pnictide superconductors

We develop an understanding of the anomalous metal state of the parent compounds of recently discovered iron based superconductors starting from a strong coupling viewpoint, including orbital degrees of freedom. On the basis of an intermediate-spin (S=1) state for the Fe^{2+} ions, we derive a Kugel-Khomskii spin-orbital Hamiltonian for the active t_{2g} orbitals. It turns out to be a highly complex model with frustrated spin and orbital interactions. We compute its classical phase diagrams and provide an understanding for the stability of the various phases by investigating its spin-only and orbital-only limits. The experimentally observed spin-stripe state is found to be stable over a wide regime of physical parameters and can be accompanied by three different types of orbital orders. Of these the orbital-ferro and orbital-stripe orders are particularly interesting since they break the in-plane lattice symmetry -- a robust feature of the undoped compounds. We compute the magnetic excitation spectra for the effective spin Hamiltonian, observing a strong reduction of the ordered moment, and point out that the proposed orbital ordering pattern can be measured in resonant X-ray diffraction.Comment: 16 pages, 12 figure

Measuring Power and Satisfaction in Societies with Opinion Leaders

International audienceOpinion leaders are actors who have some power over their followers as they are able to influence their followers' choice of action in certain instances. In van den Brink et al. (2011) we proposed a two-action model for societies with opinion leaders. We introduced a power and a satisfaction score and studied some common properties. In this paper we strengthen two of these properties and present two further properties, which allows us to axiomatize both scores for the case that followers require unanimous action inclinations of their opinion leaders to follow them independently from their own action inclinations

Do inhabitants profit from integrating a public health focus in urban renewal programmes?:A Dutch case study

Background Urban renewal traditionally involves policy sectors such as housing, transport, and employment, which potentially can enhance the health of residents living in deprived areas. Additional involvement of the public health sector might increase the health impact of these urban renewal activities. This study evaluates the health impact of an additional focus on health, under the heading of Healthy District Experiments (HDE), within districts where an urban renewal programme was carried out. Methods We evaluated changes in health outcomes before the start of the HDE and after implementation, and compared these changes with health changes in control areas, e.g. districts from the urban renewal programme where no additional HDE was implemented. Additionally, we gathered information on the content of the experiments to determine what types of activities have been implemented. Results The additional activities from the HDE were mostly aimed at strengthening the health care in the districts and at promoting physical activity. When we compared the prevalence in general health, mental health, overweight, obesity, smoking, and physical activity during the study period between the HDE districts and control districts, we found no significant differences in the rate of change. The study is limited by a small sample size and the cross-sectional nature of the data. These and other limitations are discussed. Conclusion We found no evidence for a beneficial health impact of the activities that were initiated with a specific focus on health, within a Dutch urban renewal programme. Specific attention for network management and the integration of such activities in the wider programme, as well as an allocated budget might be needed in order to sort a health impact

Autonomous planning and control of soft untethered grippers in unstructured environments

The use of small, maneuverable, untethered and reconfigurable robots could provide numerous advantages in various micromanipulation tasks. Examples include microassembly, pick-and-place of fragile microobjects for lab-on-a-chip applications, assisted hatching for in-vitro fertilization and minimally invasive surgery. This study assesses the potential of soft untethered magnetic grippers as alternatives or complements to conventional tethered or rigid micromanipulators. We demonstrate closed-loop control of untethered grippers and automated pick-and-place of biological material on porcine tissue in an unstructured environment. We also demonstrate the ability of the soft grippers to recognize and sort non-biological micro-scale objects. The fully autonomous nature of the experiments is made possible by the integration of planning and decision-making algorithms, as well as by closed-loop temperature and electromagnetic motion control. The grippers are capable of completing pick-and-place tasks of biological material at an average velocity of 1.8±0.71 mm/s and a drop-off error of 0.62±0.22 mm. Color-sensitive sorting of three micro-scale objects is completed at a velocity of 1.21±0.68 mm/s and a drop-off error of 0.85±0.41 mm. Our findings suggest that improved autonomous un-tethered grippers could augment the capabilities of current soft-robotic instruments especially in advanced tasks involving manipulation

Semi-field methods are a useful tool for the environmental risk assessment of pesticides in soil

http://dx.doi.org/10.1065/espr2008.01.47

Long-term treatment with the dopamine agonist quinagolide of patients with clinically non-functioning pituitary adenoma

OBJECTIVE: This study was performed to evaluate the effect of prolonged treatment with the dopamine agonist quinagolide on serum gonadotropin and alpha-subunit concentrations and tumor volume in patients with clinically non-functioning pituitary adenomas (CNPA). DESIGN: Ten patients with CNPA were treated with quinagolide (0.3 mg daily). The median duration of treatment was 57 months (range 36-93 months). Blood samples for measurement of serum gonadotropin and alpha-subunit concentrations were drawn before treatment, after 5 days, and at each outpatient visit. Computerized tomography or magnetic resonance imaging of the pituitary region and Goldmann perimetry were done before and at regular intervals during treatment. RESULTS: A significant decrease of serum FSH, LH or alpha-subunit concentrations was found in nine patients. The levels remained low during the entire treatment period. In two out of three patients with pre-existing visual field defects a slight improvement was shown during the first months of treatment, but eventually deterioration occurred in all three patients. A fourth patient developed unilateral ophthalmoplegia dur