Eta-mesic nuclei in relativistic mean-field theory

With the eta-nucleon (eta N) interaction Lagrangian deduced from chiral perturbation theory, we study the possible eta-mesic nuclei in the framework of relativistic mean-field theory. The eta single-particle energies are sensitive to the eta N scattering length, and increase monotonically with the nucleon number A. If the scattering length is in the range of a^{eta N}=0.75-1.05 fm and the imaginary potential V_{0}-15 MeV, some discrete states of C, O and Ne eta bound states should be identified in experiments. However, when the scattering length a^{eta N} 30 MeV, no discrete eta meson bound states could be observed in experiments.Comment: 6 page

Positions, Regions, and Clusters: Strata of Granularity in Location Modelling

Abstract. Location models are data structures or knowledge bases used in Ubiquitous Computing for representing and reasoning about spatial relationships between so-called smart objects, i.e. everyday objects, such as cups or buildings, containing computational devices with sensors and wireless communication. The location of an object is in a location model either represented by a region, by a coordinate position, or by a cluster of regions or positions. Qualitative reasoning in location models could advance intelligence of devices, but is impeded by incompatibilities between the representation formats: topological reasoning applies to regions; directional reasoning, to positions; and reasoning about set-membership, to clusters. We present a mathematical structure based on scale spaces giving an integrated semantics to all three types of relations and representations. The structure reflects concepts of granularity and uncertainty relevant for location modelling, and gives semantics to applications of RCC-reasoning and projection-based directional reasoning in location models

High-resolution x-ray imaging for microbiology at the Advanced Photon Source

Exciting new applications of high-resolution x-ray imaging have emerged recently due to major advances in high-brilliance synchrotrons sources and high-performance zone plate optics. Imaging with submicron resolution is now routine with hard x-rays: the authors have demonstrated 150 run in the 6--10 keV range with x-ray microscopes at the Advanced Photon Source (APS), a third-generation synchrotrons radiation facility. This has fueled interest in using x-ray imaging in applications ranging from the biomedical, environmental, and materials science fields to the microelectronics industry. One important application they have pursued at the APS is a study of the microbiology of bacteria and their associated extracellular material (biofilms) using fluorescence microanalysis. No microscopy techniques were previously available with sufficient resolution to study live bacteria ({approx}1 {micro}m x 4 {micro}m in size) and biofilms in their natural hydrated state with better than part-per-million elemental sensitivity and the capability of determining g chemical speciation. In vivo x-ray imaging minimizes artifacts due to sample fixation, drying, and staining. This provides key insights into the transport of metal contaminants by bacteria in the environment and potential new designs for remediation and sequestration strategies

Digital Gene Expression Profiling by 5′-End Sequencing of cDNAs during Reprogramming in the Moss Physcomitrella patens

Stem cells self-renew and repeatedly produce differentiated cells during development and growth. The differentiated cells can be converted into stem cells in some metazoans and land plants with appropriate treatments. After leaves of the moss Physcomitrella patens are excised, leaf cells reenter the cell cycle and commence tip growth, which is characteristic of stem cells called chloronema apical cells. To understand the underlying molecular mechanisms, a digital gene expression profiling method using mRNA 5′-end tags (5′-DGE) was established. The 5′-DGE method produced reproducible data with a dynamic range of four orders that correlated well with qRT-PCR measurements. After the excision of leaves, the expression levels of 11% of the transcripts changed significantly within 6 h. Genes involved in stress responses and proteolysis were induced and those involved in metabolism, including photosynthesis, were reduced. The later processes of reprogramming involved photosynthesis recovery and higher macromolecule biosynthesis, including of RNA and proteins. Auxin and cytokinin signaling pathways, which are activated during stem cell formation via callus in flowering plants, are also activated during reprogramming in P. patens, although no exogenous phytohormone is applied in the moss system, suggesting that an intrinsic phytohormone regulatory system may be used in the moss

Evolution and environment of the eastern linear pottery culture: A case study in the site of Polgár-Piócási-Dűlő

A salvage excavation preceding a major investment project was conducted in 2006–2007, during which associated settlement features of a Middle Neolithic, Eastern Linear Pottery Culture (Alföld Linearbandkeramik – ALBK) were uncovered in an area called Piócási-dűlő on the eastern outskirts of Polgár. The features of the ALBK settlement date from two periods. The cluster of multi-functional pits yielding a rich assortment of finds, the handful of post-holes and an unusual ritual well found in the southern part of the investigated area formed one unit from the earliest phase of the Middle Neolithic (ALBK I). The settlement’s other occupation can be assigned to the late phase of the Middle Neolithic (ALBK IV). Five houseplans representing the remains of timber-framed buildings outlined a distinct area with three multi-functional pits. Associated with the above features were 8 burials. The preliminary archaeobotanical results from Polgár–Piócási-dűlő are based on the plant material found within the sediments of 11 archaeological structures, which mainly represent pits and a welI. It can be stated that the natural environment offered habitats in which oak trees dominated in the local vegetation, forming floodplain forests and wooded steppes. They also provided food in the form of fruits and formed an optimal habitat for domestic animals. Arable fields were probably also established in the vicinity of the settlements, suggested by findings of macroscopic plant remains that represented cultivated species. In both settlement phases lithic production activities are manifested both by the local on-site lithic production and – most importantly – by the presence of imported, mainly mesolocal, raw materials that point to contacts with deposit areas, or off-site preliminary working of obsidian and limnoquartzites. The kit of harvesting tools and a large number of grinding stones – especially in the younger phase – for the preparation of plant food suggest a major role of plant cultivation

Graphical means for inspecting qualitative models of system behaviour

This article presents the design and evaluation of a tool for inspecting conceptual models of system behaviour. The basis for this research is the Garp framework for qualitative simulation. This framework includes modelling primitives, such as entities, quantities and causal dependencies, which are combined into model fragments and scenarios. Given a library of model fragments and a scenario describing an initial situation, the qualitative simulation engine generates predictions in the form of a state-transition graph. This rich knowledge representation has potential for educational purposes. However, communicating the contents of simulation models effectively to learners is not trivial. The predicate logic format used by Garp is not easy for non-experts to understand, and a simulation often contains so much information that it is difficult to get an overview while still having access to detailed information. To address these problems, a tool has been developed that generates graphical representations of the information contained in a qualitative simulation. This tool, named VisiGarp, incorporates a vocabulary of graphical elements for model ingredients and relationships, and combines these into interactive diagrams. VisiGarp has been evaluated by thirty students, with promising results, using a setup which included simulation results and exercises about Brazilian Cerrado ecology