Indoor radon in Slovenia

The Slovenian Radon Programme started in 1990. Since then, radon and radon short-lived decay products have been surveyed in 730 kindergartens, 890 schools, 1000 randomly selected homes, 5 major spas, 26 major hospitals, 10 major municipal water supply plants, and 8 major wineries. Alpha scintillation cells, etched track detectors, electret-based detectors and various continuously measuring devices have been used. On the basis of estimated effective doses, decisions were made on appropriate mitigation. In total, 35 buildings have been appropriately modified. The programme is displayed and results reviewed chronologically and discussed

Levels of Nanosize Radon Decay Products in Indoor Air: A Comparison for Different Environments

The fraction of unattached (fun) nanosized 222Rn short-lived decay products in indoor air has been measured in different environments and the following ranges obtained: 0.03–0.25 in kindergartens, 0.03–0.18 in schools, 0.08–0.20 in wineries, and 0.12–0.68 in a karst cave. The dependence of fun on the environmental conditions (air temperature, relative humidity and pressure), as well as on the working regime has been studied and will be discussed. Applying the dosimetric approach, dose conversion factors were calculated, based on the measured fun values, and compared to the values, obtained from epidemiological studies and currently recommended to be used in radon dosimetry

Radon levels in karst caves in Slovenia

A review is given on the radon survey in the Slovenian karst caves, those open for tourists and those for cavers and spele­ologists only. Radon concentrations differed markedly from cave to cave, as well as from point to point in the same cave. In addition to radon, in the Postojna Cave also radon decay prod­ucts (RnDP), equilibrium factor between radon and RnDP, and the unattached fraction of RnDP have been monitored. Based on highradon levels, permanent radon monitoring was intro­duced in Postojna Cave and time spent by workers in the cave limited in order to keep their exposure to radon acceptably low

Effect of optical purity on phase sequence in antiferroelectric liquid crystals

We use the discrete phenomenological model to study theoretically the phase diagrams in antiferroelectric liquid crystals (AFLCs) as a function of optical purity and temperature. Recent experiments have shown that in some systems the number of phases is reduced if the optical purity is extremely high. In some materials the SmC$_{A}^{\star}$ phase is the only stable tilted smectic phase in the pure sample. In the scope of the presented model this high sensitivity of the phase sequence in the AFLCs to optical purity is attributed to the piezoelectric coupling which is reduced if optical purity is reduced. We limit our study to three topologically equal phases - SmC$^{*}$, SmC$_{\alpha}^{*}$ and SmC$_{A}^{*}$ and show that the reduction of optical purity forces the system from the antiferroelectric to the ferroelectric phase with a possible SmC$_{\alpha}^{\star}$ between them. The effect of the flexoelectric and quadrupolar coupling is considered as well. If the phase diagram includes only two phases, SmC$^{\star}$ and SmC$$, the flexoelectric coupling is very small. The materials which exhibit the SmC$_{\alpha}^{\star}$ in a certain range of optical purity and temperature, can be expected to have a significant flexoelectric coupling that is comparable with the piezoelectric coupling. And finally, when temperature is lowered the phase sequence SmA $\to$ SmC$$ $\to$ SmC$^{\star}$ $\to$ SmC$$ is possible only in materials in which quadrupolar coupling is very strong.Comment: 17 pages including 6 figures, submitted to PR

How to Study Literary Realism as Archive Art? The Case of Charles Dickens' Later Novels

The paper proposes to approach the issue of literary realism through the prism of archive art, i.e. the artworks that are archives of objects, documents, statements, even other artworks by other artists etc. The preservation of the otherness of an entity, which is subsequently taken up and kept in an archive, is one of the key challenges involved in such projects. The second task of an archival artwork is to construct—in fact add—an encompassing totality that correlates with the authorship and gives significance to the archive-artwork as a whole. The paper scrutinizes possible links between the archival approaches to art production in the 20th and 21st centuries and the practices of realist writing beginning in the 19th century.

Nanoaerosols Including Radon Decay Products in Outdoor and Indoor Air at a Suburban Site

Nanoaerosols have been monitored inside a kitchen and in the courtyard of a suburban farmhouse. Total number concentration and number size distribution (5–1000 nm) of general aerosol particles, as measured with a Grimm Aerosol SMPS+C 5.400 instrument outdoors, were mainly influenced by solar radiation and use of farming equipment, while, indoors, they were drastically changed by human activity in the kitchen. In contrast, activity concentrations of the short-lived radon decay products 218Po, 214Pb, and 214Bi, both those attached to aerosol particles and those not attached, measured with a Sarad EQF3020-2 device, did not appear to be dependent on these activities, except on opening and closing of the kitchen window. Neither did a large increase in concentration of aerosol particles smaller than 10 or 20 nm, with which the unattached radon products are associated, augment the fraction of the unattached decay products significantly

Differential gene expression and Hog1 interaction with osmoresponsive genes in the extremely halotolerant black yeast Hortaea werneckii

<p>Abstract</p> <p>Background</p> <p>Fluctuations in external salinity force eukaryotic cells to respond by changes in the gene expression of proteins acting in protective biochemical processes, thus counteracting the changing osmotic pressure. The high-osmolarity glycerol (HOG) signaling pathway is essential for the efficient up-regulation of the osmoresponsive genes. In this study, the differential gene expression of the extremely halotolerant black yeast <it>Hortaea werneckii </it>was explored. Furthermore, the interaction of mitogen-activated protein kinase HwHog1 and RNA polymerase II with the chromatin in cells adapted to an extremely hypersaline environment was analyzed.</p> <p>Results</p> <p>A cDNA subtraction library was constructed for <it>H. werneckii</it>, adapted to moderate salinity or an extremely hypersaline environment of 4.5 M NaCl. An uncommon osmoresponsive set of 95 differentially expressed genes was identified. The majority of these had not previously been connected with the adaptation of salt-sensitive <it>S. cerevisiae </it>to hypersaline conditions. The transcriptional response in hypersaline-adapted and hypersaline-stressed cells showed that only a subset of the identified genes responded to acute salt-stress, whereas all were differentially expressed in adapted cells. Interaction with HwHog1 was shown for 36 of the 95 differentially expressed genes. The majority of the identified osmoresponsive and HwHog1-dependent genes in <it>H. werneckii </it>have not been previously reported as Hog1-dependent genes in the salt-sensitive <it>S. cerevisiae</it>. The study further demonstrated the co-occupancy of HwHog1 and RNA polymerase II on the chromatin of 17 up-regulated and 2 down-regulated genes in 4.5 M NaCl-adapted <it>H. werneckii </it>cells.</p> <p>Conclusion</p> <p>Extremely halotolerant <it>H. werneckii </it>represents a suitable and highly relevant organism to study cellular responses to environmental salinity. In comparison with the salt-sensitive <it>S. cerevisiae</it>, this yeast shows a different set of genes being expressed at high salt concentrations and interacting with HwHog1 MAP kinase, suggesting atypical processes deserving of further study.</p

Structure of nanoscale-pitch helical phases: blue phase and twist-bend nematic phase resolved by resonant soft X-ray scattering

Periodic structures of phases with orientational order of molecules, but homogenous electron density distribution: a short pitch cholesteric, blue phase and twist-bend nematic phase, were probed by a resonant soft x-ray scattering (RSoXS) at the carbon K-edge. The theoretical model shows that in case of a simple heliconical nematic structure two resonant signals corresponding to the full and half pitch band should be present, while only the full pitch band is observed in experiment. This suggests that the twist-bend nematic phase has complex structure with a double-helix, built of two interlocked, shifted helices. We confirm that the helical pitch in the twist-bend nematic phase is in a 10 nm range, for both, the chiral and achiral materials. We also show that the symmetry of a blue phase can unambiguously be determined through a resonant enhancement of x-ray diffraction signals, by including polarization effects, which are found to be an important indicator in phase structure determination