Covers of Point-Hyperplane Graphs

We construct a cover of the non-incident point-hyperplane graph of projective dimension 3 for fields of characteristic 2. If the cardinality of the field is larger than 2, we obtain an elementary construction of the non-split extension of SL_4 (F) by F^6.Comment: 10 pages, 3 figure

Curvaton Scenario with Affleck-Dine Baryogenesis

We discuss the curvaton scenario with the Affleck-Dine baryogenesis. In this scenario, non-vanishing baryonic entropy fluctuation may be generated even without primordial fluctuation of the Affleck-Dine field. Too large entropy fluctuation is inconsistent with the observations and hence constraints on the curvaton scenario with the Affleck-Dine baryogenesis are obtained. We calculate the baryonic entropy fluctuation (as well as other cosmological density fluctuations) in this case and derive constraints. Implications to some of the models of the curvaton are also discussed.Comment: 16 pages,2 figure

Modeling filamentous cyanobacteria reveals the advantages of long and fast trichomes for optimizing light exposure

Cyanobacteria form a very large and diverse phylum of prokaryotes that perform oxygenic photosynthesis. Many species of cyanobacteria live colonially in long trichomes of hundreds to thousands of cells. Of the filamentous species, many are also motile, gliding along their long axis, and display photomovement, by which a trichome modulates its gliding according to the incident light. The latter has been found to play an important role in guiding the trichomes to optimal lighting conditions, which can either inhibit the cells if the incident light is too weak, or damage the cells if too strong. We have developed a computational model for gliding filamentous photophobic cyanobacteria that allows us to perform simulations on the scale of a Petri dish using over 10(5) individual trichomes. Using the model, we quantify the effectiveness of one commonly observed photomovement strategy—photophobic responses—in distributing large populations of trichomes optimally over a light field. The model predicts that the typical observed length and gliding speeds of filamentous cyanobacteria are optimal for the photophobic strategy. Therefore, our results suggest that not just photomovement but also the trichome shape itself improves the ability of the cyanobacteria to optimize their light exposure

Study of the Growth of Entropy Modes in MSSM Flat Directions Decay: Constraints on the Parameter Space

We study how the resonant decay of moduli fields arising in the Minimal Supersymmetric Standard Model (MSSM) could affect large scale curvature perturbations in the early universe. It has been known for some time that the presence of entropy perturbations in a multi-component system can act as seeds for the curvature perturbations on all scales. These entropy perturbations could be amplified exponentially if one of the moduli decays via stochastic resonance, affecting the curvature power spectrum in the process. By imposing the COBE normalization on this power spectrum, one could put constraints on the masses and couplings of the underlying particle physics model without having to rely on collider experiments. We discuss in detail the case of the MSSM but this method could be applied to other theories beyond the Standard Model.Comment: 6 pages, 1 figure, revtex4, comments added in section II, 1 reference adde

Institutions, corporate governance and corporate governance institutions: The case of Estonia

During the last ten years, Estonia has made strong efforts in terms of the transition to a market economy. This is particularly true with respect to the soundness and transparency of monetary and fiscal policies, the privatisation of former state-owned enterprises, the development of the financial sector and the institutional setting. This paper argues that strengthening the formal institutional setting, and in particular the corporate governance institutions, is crucial to further enhance the process of economic transition of the country. It describes the current state the corporate governance structures as compared to other countries in Central and Eastern.In den letzten 10 Jahren hat Estland viele Anstrengungen in der Umwandlung in eine Marktwirtschaft unternommen. Dies trifft insbesondere auf die Stabilität und Transparenz der Währungs- und Finanzpolitik zu, der Privatisierung ehemaliger Staatsbetriebe, die Entwicklung im Finanzsektor und im institutionellen Umfeld. Der Aufsatz zeigt auf, dass die Stärkung des formellen institutionellen Umfeldes und im einzelnen auch die der Bereiche der Unternehmensorganisation essentiell wichtig für den weiteren Tranformationsprozess des Landes sind. Er stellt den heutigen Stand der Unternehmensstrukturen im Vergleich zu anderen Staaten dar

Implementing a Managed Entry Agreement Framework in Cyprus

Introduction: The aim of this study is to explore the current practice in Cyprus regarding the introduction and reimbursement of innovative pharmaceuticals through Managed Entry Agreements (MEA), assess its operational context, and suggest approaches toward spanning the knowledge gap consequential to these efforts, especially the barriers of a small country context.Areas covered: The recent introduction of a National Health System (NHS), brought about fundamental reforms in Cyprus’ Healthcare sector. Among such reforms, of particular interest, has been the introduction of a Managed Entry Agreements (MEA) mechanism. The first preliminary results indicate that despite being a small and unattractive market, Cyprus can apply a substantial MEA program. Concomitantly, it annotates the need to design an operational framework which should include, the definition of important technical parameters, clear demarcation of the scope, cooperation principles ensuring the effective operation of scientific committees, and clear delineation of what ‘value’ is. Moreover, in the context of the unified healthcare market, budget transfers should be considered, which could alleviate the inordinate budget impact of new products, which nevertheless will cut down on hospital expenditures. Narrative synthesis and health policy analysis-related resources were used.Expert opinion: The implementation of MEA in Cyprus provides an ideal testing ground for innovative reimbursement approaches. This will streamline the country’s efforts toward reimbursement of innovation, while concomitantly add to the collective MEA experience.</p

Nanowire-based very-high-frequency electromechanical resonator

Fabrication and readout of devices with progressively smaller size, ultimately down to the molecular scale, is critical for the development of very-high-frequency nanoelectromechanical systems (NEMS). Nanomaterials, such as carbon nanotubes or nanowires, offer immense prospects as active elements for these applications. We report the fabrication and measurement of a platinum nanowire resonator, 43 nm in diameter and 1.3 µm in length. This device, among the smallest NEMS reported, has a fundamental vibration frequency of 105.3 MHz, with a quality factor of 8500 at 4 K. Its resonant motion is transduced by a technique that is well suited to ultrasmall mechanical structures