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Yersinia ruckeri causes enteric redmouth disease (ERM) that mainly affects salmonid fishes and leads to significant economic losses in the aquaculture industry. An increasing number of outbreaks and the lack of effective vaccines against some serotypes necessitates novel measures to control ERM. Importantly, Y. ruckeri survives in the environment for long periods, presumably by forming biofilms. How the pathogen forms biofilms and which molecular factors are involved in this process, remains unclear. Yersinia ruckeri produces two surface-exposed adhesins, belonging to the inverse autotransporters (IATs), called Y. ruckeri invasin (YrInv) and Y. ruckeri invasin-like molecule (YrIlm). Here, we investigated whether YrInv and YrIlm play a role in biofilm formation and virulence. Functional assays revealed that YrInv and YrIlm promote biofilm formation on different abiotic substrates. Confocal microscopy revealed that they are involved in microcolony interaction and formation, respectively. The effect of both IATs on biofilm formation correlated with the presence of different biopolymers in the biofilm matrix, including extracellular DNA, RNA and proteins. Moreover, YrInv and YrIlm contributed to virulence in the Galleria mellonella infection model. Taken together, we propose that both IATs are possible targets for the development of novel diagnostic and preventative strategies to control ERM.

For hundreds of years, Great Britain possessed an empire and military that gave it an almost unrivaled power in international politics. However, as World War II drew to a close, it became increasingly evident that Great Britain no longer possessed the power it once had. In Greece, communist protest, and eventually insurrection, began as a result of disagreements in regards to the place of King George II of Greece and the future of free elections in the country after the departure of the German forces. “The Descent Unseen: Greece’s Unappreciated Place in British Political History” examines the time from outbreak of violence on December 3, 1944 and the end of June, 1945, Prime Minister Churchill’s last full month in office. As the communication between Allied leaders at the time suggested, negotiations continuously centered on how each World War II ally possessed influence, and how each party could help or hurt Great Britain’s ultimate goal of a free and democratic Greece. This project will examine how, the six-month time period witnessed the fall of Britain as a primary power in international politics, and how the influences of these nations affected the politics of Great Britain in Greece.

Ocean acidification poses multiple challenges for coral reefs on molecular to ecological scales, yet previous experimental studies of the impact of projected CO 2 concentrations have mostly been done in aquarium systems with corals removed from their natural ecosystem and placed under artificial light and seawater conditions. The Coral-Proto Free Ocean Carbon Enrichment System (CP-FOCE) uses a network of sensors to monitor conditions within each flume and maintain experimental pH as an offset from environmental pH using feedback control on the injection of low pH seawater. Carbonate chemistry conditions maintained in the -0.06 and -0.22 pH offset treatments were significantly different than environmental conditions. The results from this short-term experiment suggest that the CP-FOCE is an important new experimental system to study in situ impacts of ocean acidification on coral reef ecosystems.

To endure, coral reefs must accumulate CaCO(3) at a rate greater or equal than the sum of mechanically, biologically, and chemically mediated erosion rates. We investigated the potential role of holothurians on the CaCO(3) balance of a coral reef. These deposit feeders process carbonate sand and rubble through their digestive tract and dissolve CaCO(3) as part of their digestive process. In aquarium incubations with Stichopus herrmanni and Holothuria leucospilota total alkalinity increased by 97 +/- 13 and 47 +/- 7 mu mol kg(-1), respectively. This increase was due to CaCO3 dissolution, 81 +/- 13 and 34 +/- 6 mu mol kg(-1) and ammonia secretion, 16 +/- 2 and 14 +/- 2 mu mol kg(-1), respectively, for these species. Surveys conducted at a long-term monitoring site of community calcification (DK13) on One Tree Reef indicated that the density of sea cucumbers was approximately 1 individual m(-2). We used these data and data from surveys at Shark Alley to estimate the dissolution of CaCO(3) by the sea cucumbers at both sites. At DK13 the sea cucumber population was estimated to be responsible for nearly 50% of the nighttime CaCO(3) dissolution, while in Shark Alley for most of the nighttime dissolution. Thus, in a healthy reef, bioeroders dissolution of CaCO(3) sediment appears to be an important component of the natural CaCO(3) turnover and a substantial source of alkalinity as well. This additional alkalinity could partially buffer changes in seawater pH associated with increasing atmospheric CO(2) locally, thus reducing the impact of ocean acidification on coral growth., authorCount :6

Ocean acidification is driven by increasing atmospheric CO2 and represents a key threat to the Great Barrier Reef (GBR) and other coral reefs globally. Previous investigations have depended on studies in aquaria that are compromised by reduced ecological

High resolution calculations have been performed to simulate the detonation and subsequent blast propagation of 37.3 kilograms/(cubic meter) (TNT equivalent) of Comp B in an underground complex of chambers and tunnels like that of the Linchburg Mine near Magdalena, New Mexico. Tests were performed in this complex by the U.S. Army Water-ways Experiment Station (WES) in support of a joint US/ROK program and also for the KLOTZ Club. The calculations were performed with S-Cubed's second-order, general-purpose Eulerian hydrocode, SHARC. Because of the importance of replicating a complex facility with high fidelity so that accurate predictions of blast waveforms can be made, not only within the detonation chamber and in nearby access tunnels, but in other chambers and at the remote mine portal, the calculation was undertaken in several stages. The first stage was a two-dimensional representation, in Cartesian coordinates, of the explosive detonation and surrounding chamber. For propagation throughout the complex, a two-dimensional Cartesian "plan view" representation was used. Finally, a two-dimensional cylindrical simulation was used to propagate the blast signal to the mine portal. Careful representation of grid-scale roughness elements of the mine walls were incorporated into the calculation. The calculations are described, and results, in the form of station plots of measurable hydrodynamic parameters, are shown. The test was performed on 26 May, 1994. Limited, penitentiary comparisons between calculated and experimental results are made., See also ADM000767. Presented at the Department of Defense Explosives Safety Seminar (26th) held in Miami, Florida on 16-18 August 1994. Published in the Proceedings of the Department of Defense Explosives Safety Seminar (26th), 1994.

In support of the 5000-kg test performed by the KLOTZ Club in the summer of 1989 at Alvdalen, Sweden, S-CUBED undertook a series of calculational simulations using our second-order hydrocode, SHARC. These simulations included a two-dimensional, rigid-wall calculation of the interior and two three-dimensional calculations of the exterior. Drag-sensitive particles were included in the interior calculation to simulate the steel-plate fragments and 155-mm shells used in the test as artificial debris. Cross-sectional area measurements from the tunnel interior were used to incorporate wall irregularities in the calculation corresponding to actual measurements. Two versions of the exterior calculation were completed. One included the 7-m high berm in front of the tunnel exit; the other was done without the berm. Both of these included a representation of exterior terrain features. The exterior calculations were continued until the shock had traveled to a range of more than 100 m from the tunnel opening. Because the results of the pre-test calculations did not agree as well as had been expected with the experimental data, the interior calculation and a portion of the exterior calculation with berm were repeated after the test. Results from these calculations are shown, and comparisons with experimental data are made where they are available. Suggestions are made which may improve calculational/ experimental correspondence in the future., See also ADA235006, Volume 2. Minutes of the Explosives Safety Seminar (24th) Held in St. Louis, MO on 28-30 August 1990, p1405-1416.

The relative attractiveness of UHF, L-band and X-band for satellite communications is considered. The three frequency bands are compared on the basis of capacity, jamming protection, scintillation, multipath and doppler acquisition. It is concluded that UHF presents the greatest advantages when dealing with earth terminals required to use low-gain antennas. The implications that different types of UHF allocations have on satellite design is discussed. (Author)