Anchoring and orientational wetting of nematic liquid crystals on semi-fluorinated self-assembled monolayer surfaces

We demonstrate that it is possible to achieve exceptionally fine control over the anchoring of liquid crystals via the use of semi-fluorinated self-assembled monolayers of varying spacer length. We use this approach to map the detailed shape of an anchoring transition surface in thermodynamic phase space and to explore the links between anchoring and orientational wetting phenomena. These results allow one to design a substrate that will place a standard liquid-crystal film arbitrarily close to an anchoring transition between homeotropic and planar anchoring

Species co-occurrences in ectoparasite infracommunities: Accounting for confounding factors associated with space, time, and host community composition

1. We explored patterns of co-occurrence of ectoparasite species on individual hosts from Central Europe (Slovakia) and South America (Argentina) within and between higher taxa while controlling for confounding factors associated with variation between host individuals and host species, as well as spatial and temporal variation. We used a recently developed statistical approach, the hierarchical modelling of species communities. 2. Although the probability of pairwise associations of the majority of species in both regions did not differ from random, all significant species associations in Slovakia were positive, whereas the only three significant species associations in Argentina were negative. On average, associations between ectoparasite species belonging to different higher taxa were positive in Slovakia and negative in Argentina. 3. At the host species level, both positive and negative associations between species were detected in all higher taxa. This was also true for ectoparasite co-occurrences in the same site, habitat, or year; although the number of co-occurring species pairs with high posterior probability was much greater in Slovakia than in Argentina. 4. We conclude that consideration of species co-occurrences across the entire multi-host assemblage and control for confounding spatial and temporal factors provided important insights into parasite community structure.Fil: Krasnov, Boris R.. Ben Gurion University of the Negev; IsraelFil: Stanko, Michal. Slovak Academy of Sciences. Institute of Parasitology and Institute of Zoology; EslovaquiaFil: Lareschi, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Khokhlova, Irina S.. Ben Gurion University of the Negev; Israe

PW Vul: A classical nova with nearly solar abundances

Ultraviolet and optical spectrophotometric data were combined in order to determine the physical parameters in the expanding shell of Nova PW Vul 1984 No. 1. Ultraviolet data were obtained with the IUE satellite from August 2, 1984 (a few days after discovery) until it became too faint to study with the satellite. The last IUE exposure was obtained in June 1988 but we have continued to follow it with ground-based optical telescopes. We will present a plot that shows the variation of electron density and temperature as a function of time. Analysis of the emission line intensities show that the abundances of this very slow nova are solar for helium, carbon, and oxygen while nitrogen is 50 times solar. We have also used the CLOUDY code of Ferland to model the emission line intensities and find very good agreement with the observations. We shall display plots of representative IUE and optical spectra. 10 refs., 5 figs

Global Asthma Network survey suggests more national asthma strategies could reduce burden of asthma

Background Several countries or regions within countries have an effective national asthma strategy resulting in a reduction of the large burden of asthma to individuals and society. There has been no systematic appraisal of the extent of national asthma strategies in the world. Methods The Global Asthma Network (GAN) undertook an email survey of 276 Principal Investigators of GAN centres in 120 countries, in 2013–2014. One of the questions was: “Has a national asthma strategy been developed in your country for the next five years? For children? For adults?”. Results Investigators in 112 (93.3%) countries answered this question. Of these, 26 (23.2%) reported having a national asthma strategy for children and 24 (21.4%) for adults; 22 (19.6%) countries had a strategy for both children and adults; 28 (25%) had a strategy for at least one age group. In countries with a high prevalence of current wheeze, strategies were significantly more common than in low prevalence countries (11/13 (85%) and 7/31 (22.6%) respectively, p < 0.001). Interpretation In 25% countries a national asthma strategy was reported. A large reduction in the global burden of asthma could be potentially achieved if more countries had an effective asthma strategy. © 2017 SEICA

Global Asthma Network survey suggests more national asthma strategies could reduce burden of asthma

Background Several countries or regions within countries have an effective national asthma strategy resulting in a reduction of the large burden of asthma to individuals and society. There has been no systematic appraisal of the extent of national asthma strategies in the world. Methods The Global Asthma Network (GAN) undertook an email survey of 276 Principal Investigators of GAN centres in 120 countries, in 2013–2014. One of the questions was: “Has a national asthma strategy been developed in your country for the next five years? For children? For adults?”. Results Investigators in 112 (93.3%) countries answered this question. Of these, 26 (23.2%) reported having a national asthma strategy for children and 24 (21.4%) for adults; 22 (19.6%) countries had a strategy for both children and adults; 28 (25%) had a strategy for at least one age group. In countries with a high prevalence of current wheeze, strategies were significantly more common than in low prevalence countries (11/13 (85%) and 7/31 (22.6%) respectively, p < 0.001). Interpretation In 25% countries a national asthma strategy was reported. A large reduction in the global burden of asthma could be potentially achieved if more countries had an effective asthma strategy. © 2017 SEICA