A laboratory study of an inactivated bivalent iron restricted Salmonella enterica serovars Enteritidis and Typhimurium dual vaccine against Typhimurium challenge in chickens

A commercial inactivated iron restricted Salmonella Typhimurium and Salmonella Enterifidis vaccine was used to vaccinate chicks at I day and again at 4 weeks of age, with challenge by a high and a low dose of S. Typhimurium given either orally or by contact with seeder birds inoculated orally with a high dose of S. Typhimurium. In all three challenge regimes, the shedding of challenge strain was reduced significantly (p < 0.05) in vaccinated birds compared with unvaccinated controls. Vaccination reduced colonisation of internal organs after challenge by contact seeder birds. However, no effect of vaccination upon colonisation of internal organs after either high or low oral challenge was apparent. In conclusion, the data indicate that the vaccine should be a useful tool in the control of S. Typhimurium infection in chickens. (C) 2002 Elsevier Science B.V. All rights reserved.

The efficacy of Salenvac, a Salmonella enterica subsp. Enterica serotype Enteritidis iron-restricted bacterin vaccine, in laying chickens

The protective effect of two vaccination regimes using Salenvac, a commercially available iron-restricted Salmonella enterica subsp. Enterica serotype Enteritidis PT4 bacterin vaccine, was verified in laying birds. Immunization was intramuscular at 1 day old and again at 4 weeks of age (V2), or at 1 day and 4 weeks with a third dose at 18 weeks of age (V3). Challenge S. Enteritidis (5 to 7.5) x 10(7) colony forming units) was given intravenously at 8, 17, 23, 30 and 59 weeks of age. For all age groups, both vaccination regimes reduced significantly the number of tissues and faecal samples that were culture positive for the challenge strain. For laying birds, fewer eggs (P < 0.001) were culture positive for S. Enteritidis after challenge from vaccinated laying birds ( 56/439 batches of eggs) than unvaccinated birds (99/252 batches). The data give compelling evidence that the vaccine is efficacious and may contribute to the reduction of layer infection and egg contamination.

The Valanginian δ13C excursion may not be an expression of a global oceanic anoxic event

Marine and terrestrial sediments of the Valanginian age display a distinct positive δ13C excursion, which has recently been interpreted as the expression of an oceanic anoxic episode (OAE) of global importance. Here we evaluate the extent of anaerobic conditions in marine bottom waters and explore the mechanisms involved in changing carbon storage on a global scale during this time interval. We asses redox-sensitive trace-element distributions (RSTE; uranium, vanadium, cobalt, arsenic and molybdenum) and the quality and quantity of preserved organic matter (OM) in representative sections along a shelf-basin transect in the western Tethys, in the Polish Basin and on Shatsky Rise. OM-rich layers corresponding in time to the δ13C shift are generally rare in the Tethyan sections and if present, the layers are not thicker than several centimetres and total organic carbon (TOC) contents do not surpass 1.68 wt..%. Palynological observations and geochemical properties of the preserved OM suggest a mixed marine and terrestrial origin and deposition in an oxic environment. In the Polish Basin, OM-rich layers show evidence for an important continental component. RSTE exhibit no major enrichments during the δ13C excursion in all studied Tethyan sections. RSTE enrichments are, however, observed in the pre-δ13C excursion OM-rich “Barrande” levels of the Vocontian Trough. In addition, all Tethyan sections record higher Mn contents during the δ13C shift, indicating rather well-oxygenated bottom waters in the western Tethys and the presence of anoxic basins elsewhere, such as the restricted basins of the North Atlantic and Weddell Sea. We propose that the Valanginian δ13C shift is the consequence of a combination of increased OM storage in marginal seas and on continents (as a sink of 12C-enriched organic carbon), coupled with the demise of shallow-water carbonate platforms (diminishing the storage capacity of 13C-enriched carbonate carbon). As such the Valanginian provides a more faithful natural analogue to present-day environmental change than most other Mesozoic OAEs, which are characterized by the development of ocean-wide dysaerobic to anaerobic conditions.

Molecular and phenotypic characterization of a mouse model of oculopharyngeal muscular dystrophy reveals severe muscular atrophy restricted to fast glycolytic fibres

Oculopharyngeal muscular dystrophy (OPMD) is an adult-onset disorder characterized by ptosis, dysphagia and proximal limb weakness. Autosomal-dominant OPMD is caused by a short (GCG)8–13 expansions within the first exon of the poly(A)-binding protein nuclear 1 gene (PABPN1), leading to an expanded polyalanine tract in the mutated protein. Expanded PABPN1 forms insoluble aggregates in the nuclei of skeletal muscle fibres. In order to gain insight into the different physiological processes affected in OPMD muscles, we have used a transgenic mouse model of OPMD (A17.1) and performed transcriptomic studies combined with a detailed phenotypic characterization of this model at three time points. The transcriptomic analysis revealed a massive gene deregulation in the A17.1 mice, among which we identified a significant deregulation of pathways associated with muscle atrophy. Using a mathematical model for progression, we have identified that one-third of the progressive genes were also associated with muscle atrophy. Functional and histological analysis of the skeletal muscle of this mouse model confirmed a severe and progressive muscular atrophy associated with a reduction in muscle strength. Moreover, muscle atrophy in the A17.1 mice was restricted to fast glycolytic fibres, containing a large number of intranuclear inclusions (INIs). The soleus muscle and, in particular, oxidative fibres were spared, even though they contained INIs albeit to a lesser degree. These results demonstrate a fibre-type specificity of muscle atrophy in this OPMD model. This study improves our understanding of the biological pathways modified in OPMD to identify potential biomarkers and new therapeutic targets.

Mediterranean cyclones and windstorms in a changing climate

Changes in the frequency and intensity of cyclones and associated windstorms affecting the Medi-terranean region simulated under enhanced Greenhouse Gas forcing conditions are investigated. The analysis is based on 7 climate model integrations performed with two coupled global models (ECHAM5 MPIOM and INGV CMCC), comparing the end of the twentieth century and at least the first half of the twenty-first century. As one of the models has a considerably enhanced resolution of the atmosphere and the ocean, it is also investigated whether the climate change signals are influenced by the model resolution. While the higher resolved simulation is closer to reanalysis climatology, both in terms of cyclones and windstorm distributions, there is no evidence for an influence of the resolution on the sign of the climate change signal. All model simulations show a reduction in the total number of cyclones crossing the Mediterranean region under climate change conditions. Exceptions are Morocco and the Levant region, where the models predict an increase in the number of cyclones. The reduction is especially strong for intense cyclones in terms of their Laplacian of pressure. The influence of the simulated positive shift in the NAO Index on the cyclone decrease is restricted to the Western Mediterranean region, where it explains 10–50 % of the simulated trend, depending on the individual simulation. With respect to windstorms, decreases are simulated over most of the Mediterranean basin. This overall reduction is due to a decrease in the number of events associated with local cyclones, while the number of events associated with cyclones outside of the Mediterranean region slightly increases. These systems are, however, less intense in terms of their integrated severity over the Mediterranean area, as they mostly affect the fringes of the region. In spite of the general reduction in total numbers, several cyclones and windstorms of intensity unknown under current climate conditions are identified for the scenario simulations. For these events, no common trend exists in the individual simulations. Thus, they may rather be attributed to long-term (e.g. decadal) variability than to the Greenhouse Gas forcing. Nevertheless, the result indicates that high-impact weather systems will remain an important risk in the Mediterranean Basin.

Hydrology and geomorphology of the Upper White Nile lakes and their relevance for water resources management in the Nile basin

Remote sensing data and digital elevation models were utilized to extract the catchment hydrological parameters and to delineate storage areas for the Ugandan Equatorial Lakes region. Available rainfall/discharge data are integrated with these morphometric data to construct a hydrological model that simulates the water balance of the different interconnected basins and enables the impact of potential management options to be examined. The total annual discharges of the basins are generally very low (less than 7% of the total annual rainfall). The basin of the shallow (5 m deep) Lake Kioga makes only a minor hydrological contribution compared with other Equatorial Lakes, because most of the overflow from Lake Victoria basin into Lake Kioga is lost by evaporation and evapotranspiration. The discharge from Lake Kioga could be significantly increased by draining the swamps through dredging and deepening certain channel reaches. Development of hydropower dams on the Equatorial Lakes will have an adverse impact on the annual water discharge downstream, including the occasional reduction of flow required for filling up to designed storage capacities and permanently increasing the surface areas of water that is exposed to evaporation. On the basis of modelling studies, alternative sites are proposed for hydropower development and water storage schemes

Effect of surface restoring on subsurface variability in a climate model during 1949-2005

Initializing the ocean for decadal predictability studies is a challenge, as it requires reconstructing the little observed subsurface trajectory of ocean variability. In this study we explore to what extent surface nudging using well-observed sea surface temperature (SST) can reconstruct the deeper ocean variations for the 1949–2005 period. An ensemble made with a nudged version of the IPSLCM5A model and compared to ocean reanalyses and reconstructed datasets. The SST is restored to observations using a physically-based relaxation coefficient, in contrast to earlier studies, which use a much larger value. The assessment is restricted to the regions where the ocean reanalyses agree, i.e. in the upper 500 m of the ocean, although this can be latitude and basin dependent. Significant reconstruction of the subsurface is achieved in specific regions, namely region of subduction in the subtropical Atlantic, below the thermocline in the equatorial Pacific and, in some cases, in the North Atlantic deep convection regions. Beyond the mean correlations, ocean integrals are used to explore the time evolution of the correlation over 20-year windows. Classical fixed depth heat content diagnostics do not exhibit any significant reconstruction between the different existing observation-based references and can therefore not be used to assess global average time-varying correlations in the nudged simulations. Using the physically based average temperature above an isotherm (14 °C) alleviates this issue in the tropics and subtropics and shows significant reconstruction of these quantities in the nudged simulations for several decades. This skill is attributed to the wind stress reconstruction in the tropics, as already demonstrated in a perfect model study using the same model. Thus, we also show here the robustness of this result in an historical and observational context.