Influence of cell surface characteristics on adhesion of Saccharomyces cerevisiae to the biomaterial hydroxylapatite

The influence of the physicochemical properties of biomaterials on microbial cell adhesion is well known, with the extent of adhesion depending on hydrophobicity, surface charge, specific functional groups and acid–base properties. Regarding yeasts, the effect of cell surfaces is often overlooked, despite the fact that generalisations may not be made between closely related strains. The current investigation compared adhesion of three industrially relevant strains of Saccharomyces cerevisiae (M-type, NCYC 1681 and ALY, strains used in production of Scotch whisky, ale and lager, respectively) to the biomaterial hydroxylapatite (HAP). Adhesion of the whisky yeast was greatest, followed by the ale strain, while adhesion of the lager strain was approximately 10-times less. According to microbial adhesion to solvents (MATS) analysis, the ale strain was hydrophobic while the whisky and lager strains were moderately hydrophilic. This contrasted with analyses of water contact angles where all strains were characterised as hydrophilic. All yeast strains were electron donating, with low electron accepting potential, as indicated by both surface energy and MATS analysis. Overall, there was a linear correlation between adhesion to HAP and the overall surface free energy of the yeasts. This is the first time that the relationship between yeast cell surface energy and adherence to a biomaterial has been described

The effect of sea induced motion on offshore process equipment

The performance of offshore process equipment on floating production platforms may be reduced through imposed sea motion. Fluid sloshing inside primary separators and non-segregated storage tanks may lead to oil/water mixing. The aim of previous work into sloshing has been to prevent damage to LNG tankers and increase the stability of space rockets. Work into oil/water sloshing appears limited. A computer controlled motion simulator was developed to conduct experiments with two rectangular vessels filled with air, refined oil and water. Two single sinusoidal forcing motions were applied, pitch and surge at various amplitudes and periods. Additional experiments were conducted with combined forcing motions pitch/roll and pitch/surge. Air/water interface profiles were measured and analysed using a computer based data logging and processing system. Air/oil and oil/water profiles were recorded using high speed video equipment. Also studied were the effect of baffles in reducing interface amplitude and the effect of forcing on oil/water transfer. A linear theory was derived to predict natural frequencies of three fluid systems and a numerical model was developed to predict near resonant behaviour. Air/water experiments and numerical model showed a coupling of natural and forcing frequencies in the free surface frequency spectrum. Favourable comparisons were also seen between the numerical model and oil/water experiments. Additional experiments indicated that oil/water mixing is promoted by resonant forcing in an unbaffled vessel. The presence of baffles reduces interfacial breakup and hence reduces oil content of water.SERCThe Marine Technology DirectorateBritoi

A Study of Optical Observing Techniques for Extra-Galactic Supernova Remnants: Case of NGC 300

We present the results of a study of observational and identification techniques used for surveys and spectroscopy of candidate supernova remnants (SNRs) in the Sculptor Group galaxy NGC 300. The goal of this study was to investigate the reliability of using [Sii]/Halpha > 0.4 in optical SNR surveys and spectra as an identifying feature of extra-galactic SNRs (egSNRs) and also to investigate the effectiveness of the observing techniques (which are hampered by seeing conditions and telescope pointing errors) using this criterion in egSNR surveys and spectrographs. This study is based on original observations of these objects and archival data obtained from the Hubble Space Telescope which contained images of some of the candidate SNRs in NGC 300. We found that the reliability of spectral techniques may be questionable and very high-resolution images may be needed to confirm a valid identification of some egSNRs.Comment: 27 Figures, 10 table

Why bean beer?

Beer can be a wholesome beverage, and the art of brewing beer has been intertwined with the development of civilised society for centuries. Today, the latest valuation of the economic value of beer (by accountants Ernst and Young in 2013), reported that Europe is the world’s biggest producer of beer with over 4,500 breweries delivering around 390 million hectolitres annually – which in plain English is 68,632,200,000 pints (since 1 hectolitre is a small spillage less than 176 imperial pints). The industry employs over 2 million people, and around 125,000 of these are employed in breweries themselves. It should also be no surprise then that sales generated 53 billion Euro, which is almost doubled again by the value added from the supply chain. Also, the EU brewing sector had a trade surplus (i.e. exports were greater than imports) to the value of 3 billion Euro in 2012. Beer is serious business

Factors that affect the use of herbicides in Philippine rice farming systems

This study involves the application of a random-effects double-hurdle model to survey data to identify the farm-level factors affecting the adoption and intensity of herbicide use in rice production in the Philippines. Results broadly indicate apparent differences in the degree to which important explanatory variables affect the intensity and adoption decisions. The age of the farmer, household size, and irrigation are the significant predictors influencing the decision of farmers to use herbicides, while economic variables such as the price of herbicides, total income of farmers, and the use of bank loans or credit are the highly significant factors determining the intensity of herbicide use. Significant determinants of both the adoption and intensity decisions are land ownership, farm area, and the method of crop establishment used. Results suggest that all of the identified significant predictors in both herbicide use decisions can be considered by the national government when designing policies to reduce excessive use of herbicides or to encourage the adoption of alternative methods of weed control. This is important because for small rice producers, like the majority of Filipino farmers, improved weed management techniques that build on their traditional practices and that are compatible with their resources will be more easily adopted by farmers, relative to those that require radical change to the entire farming system.Herbicide use, Double-hurdle model, Adoption, Rice farming system., Demand and Price Analysis,

RIMPhil: a bioeconomic model for integrated weed management of annual barnyardgrass (Echinochloa crus-galli) in Philippine rice farming systems

This paper describes a complex, dynamic simulation model that has been developed for the analysis of integrated weed management programmes for the control of annual barnyardgrass (Echinochloa crus-galli) in rice farming systems in the Philippines. Users of the model may simulate any feasible combination of 49 weed treatments options across wet and dry cropping seasons over 5, 10, 15, and 20 year periods, subject to a predetermined sequence of planting methods. The main outputs of the model include weed seed and plant densities and seasonal and annualised profit over the simulated planning horizon. Model output emphasises the substantial economic benefits associated with effective long-term weed management strategies. In addition, the most-profitable weed densities are found to be much lower than those usually recommended to producers, indicating the importance of considering economic factors in the formulation of management recommendations. Results broadly indicate that a mixture of chemical and non-chemical treatments provides good weed control in rice crops, and maximises long-term profit for systems where the main weed is annual barnyardgrass. However, the performance of this strategy is influenced by crop establishment method and weed density level. These indicative results emphasise the value of the model for guiding the efficient control of annual barnyardgrass in rice crops in the Philippines.Barnyardgrass, Bioeconomic model, Integrated weed management, Rice farming systems., Agricultural and Food Policy, Crop Production/Industries, Environmental Economics and Policy, Farm Management,