The dynamics of opinion in hierarchical organizations

We study the mutual influence of authority and persuasion in the flow of opinion. Many social organizations are characterized by a hierarchical structure where the propagation of opinion is asymmetric. In the normal flow of opinion formation a high-rank agent uses its authority (or its persuasion when necessary) to impose its opinion on others. However, agents with no authority may only use the force of its persuasion to propagate their opinions. In this contribution we describe a simple model with no social mobility, where each agent belongs to a class in the hierarchy and has also a persuasion capability. The model is studied numerically for a three levels case, and analytically within a mean field approximation, with a very good agreement between the two approaches. The stratum where the dominant opinion arises from is strongly dependent on the percentage of agents in each hierarchy level, and we obtain a phase diagram identifying the relative frequency of prevailing opinions. We also find that the time evolution of the conflicting opinions polarizes after a short transient.Comment: 6 pages, 5 figures, submitted to Phys. Rev.

Investigation of thermal and magnetic properties of defects in a spin-gap compound NaV2O5

The specific heat, magnetic susceptibility and ESR signals of a Na-deficient vanadate Na_xV_2O_5 (x=1.00 - 0.90) were studied in the temperature range 0.07 - 10 K, well below the transition point to a spin-gap state. The contribution of defects provided by sodium vacancies to the specific heat was observed. It has a low temperature part which does not tend to zero till at least 0.3 K and a high temperature power-like tail appears above 2 K. Such dependence may correspond to the existence of local modes and correlations between defects in V-O layers. The magnetic measurements and ESR data reveal S=1/2 degrees of freedom for the defects, with their effective number increasing in temperature and under magnetic field. The latter results in the nonsaturating magnetization at low temperature. No long-range magnetic ordering in the system of defects was found. A model for the defects based on electron jumps near vacancies is proposed to explain the observed effects. The concept of a frustrated two-dimensional correlated magnet induced by the defects is considered to be responsible for the absence of magnetic ordering.Comment: 6 pages, 8 figure

Distribution of DHPS Mutations Among ITS Subtypes of P. carinii f. sp. hominis

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92387/1/j.1550-7408.2001.tb00481.x.pd

GAMBE: Thermal neutron detection system based on a sandwich configuration of silicon semiconductor detector coupled with neutron reactive material

© 2019 Elsevier Ltd Silicon semiconductor detectors are used efficiently for neutron detection when coated with a suitable material. They detect secondary reaction products resulting from the interaction of thermal neutrons with a neutron sensitive material such as 6 LiF. In the present work, the efficiency of the thermal neutron detector system, GAMBE, is discussed. This detector system based on two silicon sensors of 1 cm 2 active area and a layer of 6 LiF (1.5±0.6) mg/cm 2 thick in a sandwich configuration. This arrangement achieves total and coincidence detection efficiency of (4.1±0.5)% and (0.9±0.3)% respectively. The coincidence method defines a true neutron hit by the simultaneous signal recorded by the two sensors facing the conversion film. This coincidence methodology is applied to enhance the rejection factor of fake hits due to high gamma background conditions up to 10 8 as discussed in previous work. Geant simulation indicates that total and coincidence detection efficiency up to 55% and 18% are possible using an advanced design of stacked detectors

Multiple Front Propagation Into Unstable States

The dynamics of transient patterns formed by front propagation in extended nonequilibrium systems is considered. Under certain circumstances, the state left behind a front propagating into an unstable homogeneous state can be an unstable periodic pattern. It is found by a numerical solution of a model of the Fr\'eedericksz transition in nematic liquid crystals that the mechanism of decay of such periodic unstable states is the propagation of a second front which replaces the unstable pattern by a another unstable periodic state with larger wavelength. The speed of this second front and the periodicity of the new state are analytically calculated with a generalization of the marginal stability formalism suited to the study of front propagation into periodic unstable states. PACS: 47.20.Ky, 03.40.Kf, 47.54.+rComment: 12 page

The Inter-organizational Business Case in ES Implementations: Exploring the Impact of Coordination Structures and Their Properties

Developing the business case (BC) for an inter-organizational network is a major challenge. Factors like competition and differences in semantics between actors influence the stakeholders’ willingness to share information necessary for the BC development. In this paper we develop an exploratory framework showing the effect that coordination structure and project scope have on the development of a shared BC. We defined several coordination properties, such as competition, decision making location and decision power that mitigate this effect. We applied the framework in a case study where a BC is developed for an inter-organizational network. Our findings show that current BC development methods need to be re-stated and complemented by extra tools and interventions to support stakeholders in the inter-organizational specific setting