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Neoparamoeba perurans is a free-living protist that can cause Amoebic Gill Disease (AGD) in a number of teleost fish species and is responsible for substantial losses of farmed Atlantic salmon in various locations world-wide. The intimate relationship of the amoeba with bacteria can present challenges for its laboratory culture and drug discovery programmes. Herein, we report our findings on the bacteria that live in close association with N. perurans. These include the presence of various marine bacteria, including those of the Pseudoalteromonas, Halomonas, Cellulophaga and Mesonia genera. However, next generation sequencing (NGS) identified a substantial proportion of sequences that matched with the Vibrio genus in filtered amoebae and not in the medium suggesting an intimate association between this genus and N. perurans. Fluorescence in-situ hybridization (FISH) revealed that Vibrio species are predominantly found within N. perurans. This information is important in the management and control of AGD as bacteria associated with N. perurans may have relevance to virulence and advancement of disease.

Amoebic Gill Disease (AGD) is a major problem in the aquaculture industry, as it is responsible for substantial losses of farmed Atlantic salmon in various worldwide locations. The disease is caused by the usually free-living Paramoeba perurans compromising the gills through the resulting development of hyperplastic lesions and lamellar fusion. These structural changes result in a reduction in the functional surface area of the gill tissues. Recent research has focused on identifying bacteria present within a culture of P. perurans, through performing isolation and identification of bacteria present in the cultures using 16S sequencing. Further NGS sequencing was performed from various culture conditions to provide insight into the changes of the bacterial microbiome during amoeba culture. As attempts to isolate the amoeba from the bacterial contamination has been unsuccessful, consideration into a possible symbiotic relationship between the amoeba and bacteria was considered. A filtering method was used to attempt to identify the genera of bacteria present within the amoeba. The isolation and 16S sequencing identified the presence of various marine bacteria, including those of the Pseudoalteromonas, Halomonas, Cellulophaga and Mesonia genera. The NGS sequencing identified a substantial proportion of sequences to match the Vibrio genus and suggests an association between this genus and the amoeba. If symbiotic relationships between specific bacteria and amoeba can be confirmed, the bacteria could potentially be used as an indicator organism for the risk of AGD outbreak. It may also provide an indirect target for the control and treatment of AGD.

SUMMARYProtists are a diverse collection of eukaryotic organisms that account for a significant global infection burden. Often, the immune responses mounted against these parasites cause excessive inflammation and therefore pathology in the host. Elucidating the mechanisms of both protective and harmful immune responses is complex, and often relies of the use of animal models. In any immune response, leucocyte trafficking to the site of infection, or inflammation, is paramount, and this involves the production of chemokines, small chemotactic cytokines of approximately 8–10 kDa in size, which bind to specific chemokine receptors to induce leucocyte movement. Herein, the scientific literature investigating the role of chemokines in the propagation of immune responses against key protist infections will be reviewed, focussing onPlasmodiumspecies,Toxoplasma gondii, Leishmaniaspecies andCryptosporidiumspecies. Interestingly, many studies find that chemokines can in fact, promote parasite survival in the host, by drawing in leucocytes for spread and further replication. Recent developments in drug targeting against chemokine receptors highlights the need for further understanding of the role played by these proteins and their receptors in many different diseases.

The combustion characteristics of six middle distillate oil blends were examined using the controlled combustion testing facilities at the Energy Research Laboratories of the Canada Centre for Minerals and Energy Technologies (CANMET). Test fuels were specifically prepared for a research project to study the impact of changes in commercial heating fuel composition on the combustion performance of a residential heating appliance. Compositional formulation was modified in such a way that the fuel properties still met Canadian national heating fuel specifications. The experimental combustion conditions were set to reflect possible poor operating situations found in the field and to accelerate the emissions data acquisition process. The results from this combustion study indicate that performance deteriorated with a decrease in the fuel hydrogen-carbon ratio, which relates to the decreasing ratio of aliphatic, saturated hydrocarbon to aromatic hydrocarbon concentrations. When concentrations of high boiling, high molecular weight aromatic hydrocarbons are increased, while simultaneously reducing those of low molecular weight hydrocarbons, other fuel properties, such as flash point, distillation range, density and viscosity are altered. These compositional changes resulted in poorer burner performance characteristics and higher pollution emissions. Video recordings of the combustion experiments revealed progressive degradation of transient flame characteristics as the fuel reformulation changed from moderate to severe. Performance degradation was more pronounced at 7°C, significantly colder than the normal operating temperature range of a residential heating appliance. The effects of hydrocarbon compositional changes in distillate heating fuels on combustion performance, especially in terms of increased aromatics concentrations, were discussed.

Following declining numbers in some areas in the 1980s, Mute Swan numbers have shown a marked increase in recent years. In some areas, such as the Wylye Valley in Wiltshire, this increase has been accompanied by complaints of damage caused to farming and fishing interests. The population dynamics of this population of Mute Swans is described, including its habitat preferences, and these findings are related to possible management options. As the Wylye catchment already receives immigrants from unknown sources, culling and translocation are not appropriate solutions to prevent agricultural damage. A combination of scaring, repellents and the provision of alternative food sources could provide the most successful long‐term management. Whilst different techniques may be needed to resolve the fishing problem, it is considered that integration of selected management options is most likely to provide maximum benefit.

Reaction kinetics of char-CO2 gasification at atmospheric pressure were investigated in a thermobalance reactor using four coals of different rank. Effects of coal rank (lignite to semianthracite), particle size (0.18 to 1.00 mm), reaction temperature (700 to 900 °C) and concentration (30 to 100 vol%) of the reactant gas (CO2) on the conversion rate of char gasification were determined. The gasification reaction order and the reaction rate constant were determined from the conversion data, and the activation energy of the reaction was determined from the Arrhenius plot. Chemical reactivity of the char was correlated with the carbon content of the parent coals, particle size, partial pressure of CO2 and reaction temperature. The experimental conversion data are well represented by the unreacted shrinking core model in which chemical reaction is the rate-controlling step.

This paper presents the gasification reactivity in air of untreated and demineralized chars derived from Canmore (semi-anthracite) and Mt. Klappan (anthracite) coals using a thermogravimetric analysis technique. The effects of mineral content, particle size and surface physical properties on the reactivity of these chars were investigated. It was found that the gasification reactivity of the char decreased with increased particle size and decreased mineral content. A reaction dimension, D R , was determined from logarithmic plots of gasification reactivity against particle size. This reaction rate/particle radius relationship is an example of a fractal scaling law where the exponent is a function of the effective fractal dimension of the process. The values determined for D R were 2.78 and 2.40 for Canmore and Mt. Klappan chars respectively. The specific surface area measured by carbon dioxide adsorption at 298 K did not correlate with reactivity or particle size data whereas the results from mercury porosimetry indicated possible correlations.

Results of a gasification study of five Canadian coals in a 100g laboratory fixed-bed gasifier are reported. The coals were three bituminous coals (Byron Creek, Prince and Devco) and two lignites (Coronach and Bienfait). When gasified in an equal mixture of nitrogen and oxygen at 850 °C, the lignites reacted more rapidly and produced more liquid and gaseous products than the bituminous coals, whereas the bituminous coals produced more methane but less carbon monoxide. Overall rates for both the gasification and combustion processes were 3.20, 2.80, 1.84, 1.70 and 1.25 wt% carbon conversion per min for Coronach, Bienfait, Prince, Byron Creek and Devco coals, respectively.

The pore volume, surface area and compressibility of eleven Canadian coals, varying in rank from lignite to semianthracite, have been determined by mercury porosimetry, gas adsorption method and relations derived from helium and mercury densities. The total pore volume was measured in the diameter range of 0.2 nm–2.98 μm, which was subdivided into two groups, namely the micropore region (< 0.0036 μm) and the combined meso- and macropore region (0.0036–2.98 μm). It has been determined that the porosity of the eleven coals studied varies from 2 to 39%. It has been found that the total pore volume, micropore volume, surface area and the apparent compressibility of these coals decrease with increase in the carbon content, or the rank of the coals. The effect of the total pore volume, micropore volume and surface area on chemical reactivity of the coal is discussed separately. A good correlation was obtained between the carbon content and helium density of the coal after correction is made for the mineral content.

The pore volume, surface area, compressibility and reactivity of 12 chars derived from Canadian coals ranking from lignite to anthracite, have been determined by mercury porosimetry, gas adsorptiondesorption with N 2 and CO 2 adsorbates, helium and mercury densities and thermogravimetric technique. A comparison of the pore structure between the chars and their parent coals was made based on the results obtained from these techniques. The reactivity of chars was correlated with their physical and chemical properties. It has been found that a single relationship exists between the helium density and the carbon content of the coals and their chars. The chars are more porous but less compressible when compared with their parent coals.

Cokes derived from two Alberta oil sands operations were gasified at feed rates of about 20 kg h −1 in steam and oxygen using a 0.30 m diameter atmospheric pressure gasifier operated as either a fluidized or a spouted bed. Effects of oxygen/coke ratio and temperature on gas composition, heating value and carbon conversion are presented. In situ sulphur capture using dolomite was demonstrated and the effect of gasification catalyst shown. Gas composition is compared with predictions of an equilibrium model.

The chemical reactivity of nine Canadian coals was determined in a laboratory fixed-bed gasifier under two experimental conditions; with steam and without steam. It has been found that in general the reactivity of a coal increases with decrease in rank. The present reaction systems are well represented by the shrinking core model for the range of coals tested. The chemical composition of the product gas from steam gasification of these coals indicates that the steam gasification reaction favours the water-gas shift reaction rather than the carbon-steam reaction.

The reactivities of eight Canadian coal-derived chars of four different ranks were measured thermogra-vimetrically at 500°C. It has been found that char reactivity decreases with increase in the carbon content (or rank) of the parent coal. Chars containing more calcium and magnesium oxides have higher reactivities. The experimental results of mass conversion are well represented by the shrinking core model in which the initial stage of the reaction is kinetically controlled by chemical reaction and the later stage by gas diffusion through the ash.