Slow surface wave damping in plasmas with anisotropic viscosity and thermal conductivity

This paper studies the damping of slow surface MHD waves propagating along the equilibrium magnetic field on a finite-thickness magnetic interface. The plasma is assumed to be strongly magnetised, and the full Braginskii's expressions for viscosity and the heat flux are used. The primary focus of the paper is on the competition between resonant absorption in the thin dissipative layer embracing the ideal resonant position and the bulk wave damping due to viscosity and thermal conductivity as damping mechanisms for surface MHD waves. The dependence of the wave damping decrement on the wave length and the dissipative coefficients is studied. Application of the obtained results to the surface MHD wave damping in the solar chromosphere is discussed

Guest editorial: industrial districts: towards the future

The notion of Industrial District (ID) was introduced by Alfred Marshall in the Principles of Economics (1890) and reintroduced a hundred years later by Giacomo Becattini (1979) in the main body of scientific literature. Since the 1990s, the notion of the Marshallian Industrial District (MID) has diffused rapidly in the scientific economic literature in English (Figure 1). What is extraordinary, however, is the variety and dynamism of the topics that the literature of the ID has produced over the past 40 years. When Giacomo Becattini published the seminal article “Dal settore industriale al distretto industriale. Alcune considerazioni sull’unità d’indagine dell’economia industriale” (the English version can be found in Becattini, 2004), in 1979, articles referring to ID were very scarce and came mainly from English economic historians analyzing IDs. From that moment on, the ID acquired its own entity, and a wide variety of topics on IDs began to be discussed; in the 1980s, typically those such as understanding sectors vs districts, local organization of production, the role of small firms, entrepreneurship, labor markets, technical change, among many mor

Narrow-band photodetection based on M-plane GaN films

Rapid identification of a range of hazardous airborne biological and chemical agents requires simultaneous detection at several specific wavelengths, and consequently a set of photodetectors with very narrow-band spectral responsivity. We demonstrate two ultraviolet photodetection configurations based on strained M-plane GaN films on LiAlO2(100) substrates grown by molecular-beam epitaxy with a detection bandwidth below 8 nm. The optical band gap of the film depends on the orientation of the linear polarization of the incident light relative to the c-axis of GaN, which lies in the film plane. The first configuration consists of a polarizationsensitive planar Schottky photodetector and a filter. An orthogonal alignment of the c-axis of the photodetector and the filter produces a detection system with a peak responsivity at 360 nm and a bandwidth of 6 nm. The second one consists of two planar Schottky photodetectors with their c-axes oriented perpendicular to each other. The difference signal between the two photodetectors produces a peak responsivity at 358 nm and a bandwidth of 7.3 nm

Involvement of the cohesin cofactor PDS5 (SPO76) during meiosis and DNA repair in Arabidopsis thaliana

Maintenance and precise regulation of sister chromatid cohesion is essential for faithful chromosome segregation during mitosis and meiosis. Cohesin cofactors contribute to cohesin dynamics and interact with cohesin complexes during cellcycle. One of these, PDS5, also known as SPO76, is essential during mitosis and meiosis in several organisms and also plays a role in DANN repair. In yeast, the complex Wapl-Pds5 controls cohesion maintenance and colocalizes with cohesin complexes into chromosomes. In Arabidopsis, AtWAPL proteins are essential during meiosis, however, the role of AtPDS5 remains to be ascertained. Here we have isolated mutants for each of the five AtPDS5 genes(A–E) and obtained, after different crosses between them, double,triple,and even quadruple mutants (Atpds5a Atpds5b Atpds5c Atpds5e). Depletion of AtPDS5 proteins has a weak impact on meiosis, but leads to severe effects on development, fertility, somatic homologous recombination (HR) and DANN repair. Furthermore, this cohesin cofactor could be important for the function of the AtSMC5/AtSMC6 complex. Contrarily to ist function in other species, our results suggest that AtPDS5 is dispensable during the meiotic division of Arabidopsis, although it plays an important role in DANN repair by HR

Refining a Bayesian network using a chain event graph

The search for a useful explanatory model based on a Bayesian Network (BN) now has a long and successful history. However, when the dependence structure between the variables of the problem is asymmetric then this cannot be captured by the BN. The Chain Event Graph (CEG) provides a richer class of models which incorporates these types of dependence structures as well as retaining the property that conclusions can be easily read back to the client. We demonstrate on a real health study how the CEG leads us to promising higher scoring models and further enables us to make more refined conclusions than can be made from the BN. Further we show how these graphs can express causal hypotheses about possible interventions that could be enforced

SME modes of innovation in European catching-up countries: The impact of STI and DUI drivers on technological innovation

At the intersection of SME innovation and innovation systems, this study investigates the characteristics of SME innovation modes in catching-up European countries (Southern, and Central and Eastern European) and compare it with selected among the most advanced countries in Europe as a mean to show key differences. Distinguishing between STI (Science, Technology and Innovation) and DUI (learning-by-Doing, Using and Interacting) innovation drivers, and analyzing their impact on technological innovation we study 29,834 SMEs innovation in 15 countries. We argue that the most effective SME innovation modes in catching-up countries are peculiar vis-à-vis other types of countries (e.g. advanced economies). Results show how their economic, institutional and innovation context influence SME forms of knowledge and learning. In general, catching-up countries show effective DUI-type collaborations for process innovations, while showing more limited returns than advanced countries from the STI mode of innovation