A wetting and drying scheme for ROMS

This paper is not subject to U.S. copyright. The definitive version was published in Computers & Geosciences 58 (2013): 54-61, doi:10.1016/j.cageo.2013.05.004.The processes of wetting and drying have many important physical and biological impacts on shallow water systems. Inundation and dewatering effects on coastal mud flats and beaches occur on various time scales ranging from storm surge, periodic rise and fall of the tide, to infragravity wave motions. To correctly simulate these physical processes with a numerical model requires the capability of the computational cells to become inundated and dewatered. In this paper, we describe a method for wetting and drying based on an approach consistent with a cell-face blocking algorithm. The method allows water to always flow into any cell, but prevents outflow from a cell when the total depth in that cell is less than a user defined critical value. We describe the method, the implementation into the three-dimensional Regional Oceanographic Modeling System (ROMS), and exhibit the new capability under three scenarios: an analytical expression for shallow water flows, a dam break test case, and a realistic application to part of a wetland area along the Georgia Coast, USA.We acknowledge support for studies demonstrated in this manuscript that were supported by the National Science Foundation,Division of Industrial Innovation and Partnerships (IIP)under the 3470Z. Defne etal./ Renewable Energy 36(2011)3461e3471 Partnerships for Innovation Program Grant IIP-0332613,and from the Strategic Energy Institute at Georgia Institute of Technology via a Creating Energy Options grant and the 104B Georgia Water Resources Institute Funding Program,and also by the Department of Energy,Wind and Hydropower Technologies Program award number DE-FG36-08GO18174 and by the state of Georgia

The effects of ambient temperature on the compaction of pharmaceutical powders

International audienceThis article presents an experimental study of the effects of raised ambient temperature in dies and punches on the compaction of pharmaceutical powders. The experiments use an instrumented hydraulic press having a temperature-controlled enclosure allowing the ambient temperature of die and punch to be varied from 20 to 57 degrees C. A pharmaceutical powder was compacted at temperatures in this range and mechanical parameters, such as stress transfer ratio, stress transmission ratio, and die-wall friction, were analysed to examine the effects of heat transfer between tools and powder. In particular, it is shown that increasing the environmental temperature of die and punch increases the transfer ratio and the die-wall friction. The radial pressure is also slightly increased at the first stages of the compaction. However, the stress transmission is reduced by increasing the temperature. This may indicate an increase of shear stress. It is also observed that the particles undergoing compaction are `softened' by increase of the temperature. This softening is certainly due to rise in temperature of the powder generated by the compaction and by the heat flux transfer between the die and the tablet. It is suggested that these effects could be important in industrial tablet production installations without air conditioning and thus subject to variations in ambient temperature

Feral swine \u3ci\u3eSus scrofa\u3c/i\u3e: a new threat to the remaining breeding wetlands of the Vulnerable reticulated flatwoods salamander \u3ci\u3eAmbystoma bishopi\u3c/i\u3e

Feral swine Sus scrofa have been implicated as a major threat to sensitive habitats and ecosystems as well as threatened wildlife. Nevertheless, direct and indirect impacts on threatened species (especially small, fossorial species) are not well documented. The decline of the U.S. federally endangered reticulated flatwoods salamander Ambystoma bishopi, categorized as Vulnerable on the IUCN Red List, has been rapid and there are few remaining breeding locations for this species. The flatwoods salamander depends on complex herbaceous vegetation in all life stages, including eggs, larvae and adults. Historically sets of hog tracks have been observed only occasionally in the vicinity of monitored reticulated flatwoods salamander breeding wetlands, and damage to the wetlands had never been recorded. However, during the autumn–winter breeding season of 2013-2014 we observed a large increase in hog sign, including extensive rooting damage, in known flatwoods salamander breeding wetlands. Our objective was to assess the amount of hog sign and damage in these wetlands and to take corrective management actions to curb additional impacts. Of 28 wetlands surveyed for hog sign, presence was recorded at 68%, and damage at 54%. Of the 11 sites known to be occupied by flatwoods salamanders in 2013-2014, 64% had presence, and 55% had damage. We found that regular monitoring of disturbance in wetland habitats was a valuable tool to determine when intervention was needed and to assess the effectiveness of intervention. Habitat damage caused by feral hogs poses a potentially serious threat to the salamanders, which needs to be mitigated using methods to control and exclude hogs from this sensitive habitat

Lie families: theory and applications

We analyze families of non-autonomous systems of first-order ordinary differential equations admitting a common time-dependent superposition rule, i.e., a time-dependent map expressing any solution of each of these systems in terms of a generic set of particular solutions of the system and some constants. We next study relations of these families, called Lie families, with the theory of Lie and quasi-Lie systems and apply our theory to provide common time-dependent superposition rules for certain Lie families.Comment: 23 pages, revised version to appear in J. Phys. A: Math. Theo

A peptide mimic of the chemotaxis inhibitory protein of Staphylococcus aureus: towards the development of novel anti-inflammatory compounds

Complement factor C5a is one of the most powerful pro-inflammatory agents involved in recruitment of leukocytes, activation of phagocytes and other inflammatory responses. C5a triggers inflammatory responses by binding to its G-protein-coupled C5a-receptor (C5aR). Excessive or erroneous activation of the C5aR has been implicated in numerous inflammatory diseases. The C5aR is therefore a key target in the development of specific anti-inflammatory compounds. A very potent natural inhibitor of the C5aR is the 121-residue chemotaxis inhibitory protein of Staphylococcus aureus (CHIPS). Although CHIPS effectively blocks C5aR activation by binding tightly to its extra-cellular N terminus, it is not suitable as a potential anti-inflammatory drug due to its immunogenic properties. As a first step in the development of an improved CHIPS mimic, we designed and synthesized a substantially shorter 50-residue adapted peptide, designated CHOPS. This peptide included all residues important for receptor binding as based on the recent structure of CHIPS in complex with the C5aR N terminus. Using isothermal titration calorimetry we demonstrate that CHOPS has micromolar affinity for a model peptide comprising residues 7–28 of the C5aR N terminus including two O-sulfated tyrosine residues at positions 11 and 14. CD and NMR spectroscopy showed that CHOPS is unstructured free in solution. Upon addition of the doubly sulfated model peptide, however, the NMR and CD spectra reveal the formation of structural elements in CHOPS reminiscent of native CHIPS