The effect of subminimal inhibitory concentrations of antibiotics on virulence factors expressed by Staphylococcus aureus biofilms.

Aims: The effect of subminimal inhibitory concentrations (sub-MICs) of cefalexin, ciprofloxacin and roxithromycin was investigated on some virulence factors [e.g. coagulase, Toxic Shock Syndrome Toxin 1 (TSST-1) and biofilm formation] expressed by Staphylococcus aureus biofilms.

Nanoscopic morphological changes in yeast cell surfaces caused by oxidative stress: an atomic force microscopic study.

Nanoscopic changes in the cell surface morphology of the yeasts Saccharomyces cerevisiae (strain NCYC 1681) and Schizosaccharomyces pombe (strain DVPB 1354), due to their exposure to varying concentrations of hydrogen peroxide (oxidative stress), were investigated using an atomic force microscope (AFM). Increasing hydrogen peroxide concentration led to a decrease in cell viabilities and mean cell volumes, and an increase in the surface roughness of the yeasts. In addition, AFM studies revealed that oxidative stress caused cell compression in both S.

Morphological changes in textile fibres exposed to environmental stresses: atomic force microscopic examination.

The ability of the atomic force microscope (AFM) to investigate the nanoscopic morphological changes in the surfaces of fabrics was examined for the first time. This study focussed on two natural (cotton and wool), and a regenerated cellulose (viscose) textile fibres exposed to various environmental stresses for different lengths of times. Analyses of the AFM images allowed us to measure quantitatively the surface texture parameters of the environmentally stressed fabrics as a function of the exposure time.

Effect of (+)-usnic acid on mitochondrial functions as measured by mitochondria-specific oligonucleotide microarray in liver of B6C3F1 mice.

Usnic acid is a lichen metabolite used as a weight-loss dietary supplement due to its uncoupling action on mitochondria. However, its use has been associated with severe liver disorders in some individuals. Animal studies conducted thus far evaluated the effects of usnic acid on mitochondria primarily by measuring the rate of oxygen consumption and/or ATP generation.

Characterization of a novel air-liquid interface biofilm of Pseudomonas fluorescens SBW25.

Pseudomonads are able to form a variety of biofilms that colonize the air-liquid (A-L) interface of static liquid microcosms, and differ in matrix composition, strength, resilience and degrees of attachment to the microcosm walls. From Pseudomonas fluorescens SBW25, mutants have evolved during prolonged adaptation-evolution experiments which produce robust biofilms of the physically cohesive class at the A-L interface, and which have been well characterized. In this study we describe a novel A-L interface biofilm produced by SBW25 that is categorized as a viscous mass (VM)-class biofilm.

Anomalous diffusion of heterogeneous populations characterized by normal diffusion at the individual level.

The characterization of the dispersal of populations of non-identical individuals is relevant to most ecological and epidemiological processes. In practice, the movement is quantified by observing relatively few individuals, and averaging to estimate the rate of dispersal of the population as a whole. Here, we show that this can lead to serious errors in the predicted movement of the population if the individuals disperse at different rates.

Restoration of stamp marks on steel components.

Stamp marks are used as a unique identification for a range of items, but these can be erased for criminal activities. Erased marks can sometimes be recovered by etching or magnetic means. The present study looked at the application of Fry's reagent to recover erased marks from steel.

Development of an etching paste.

The recovery of erased identification marks is a problem for the forensic scientist, particularly with respect to vehicles and firearms. The widely accepted procedure for steel imprints is to use Fry's reagent. The present study examined the possibility of forming a paste that may be easier to use.

Comparing the performance of UASB and GRABBR treating low strength wastewaters.

Anaerobic technologies have proved successful in the treatment of various high strength wastewaters with perceptible advantages over aerobic systems. The applicability of anaerobic processes to treat low strength wastewaters has been increasing with the evolution of high-rate reactors capable of achieving high sludge retention time (SRT) when operating at low HRT. However, the performance of these systems can be affected by high variations in flow and wastewater composition.

Applications of differential scanning calorimetry in developing cryopreservation strategies for Parkia speciosa, a tropical tree producing recalcitrant seeds.

Shoot-tips of Parkia speciosa, a recalcitrant seed producing tropical leguminous tree withstood cryopreservation using encapsulation-vitrification in combination with trehalose preculture. Differential scanning calorimetry (DSC) revealed that trehalose moderated the thermal characteristics of the shoot-tips. A 30 min PVS2 treatment had the lowest glass transition temperature (Tg) (-50.

A cost comparison of traditional drainage and SUDS in Scotland.

The Dunfermline Eastern Expansion (DEX) is a 350 ha mixed development which commenced in 1996. Downstream water quality and flooding issues necessitated a holistic approach to drainage planning and the site has become a European showcase for the application of Sustainable Urban Drainage Systems (SUDS). However, there is minimal data available regarding the real costs of operating and maintaining SUDS to ensure they continue to perform as per their design function.

Deployment of the encapsulation-dehydration protocol to cryopreserve microalgae held at the Sammlung von Algenkulturen, Universitat Gottingen, Germany.

Encapsulation-dehydration was applied to cryopreserve 14 diverse algal strains, representing eukaryotic terrestrial microalgae; of these 12 survived to form cell colonies after recovery from cryostorage. Surviving algae had varying degrees of tolerance to osmotic dehydration and desiccation in this vitrification-based cryoprotective strategy. The extent of algal regrowth was affected by the mode of desiccation (silica gel or air-flow), the duration of evaporative desiccation and exposure to light during early recovery phase.

Cryopreservation of avian spermatozoa.

This chapter describes a simple system for cryopreservation of avian spermatozoa as pellets, formed by dropping volumes of sperm suspension directly into liquid nitrogen with dimethylacetamide as cryoprotectant. The method originates from the group at the Research Institute of Farm Animal Breeding and Genetics at St. Petersburg-Pushkin and is described here for chicken spermatozoa, but has also been adapted successfully for other species, such as Houbara bustards and pheasants.

Circuit assemblages derived from net dinucleotide values provide a succinct identity for the HIV-1 genome and each of its genes.

Dinucleotide composition has been recognized as a species-specific characteristic of organisms for more than 20 years. Lang (2000, Bioinformatics, 16, 212-221), found that in Monilinia rRNA a species-specific identity is conserved when dinucleotide counts are compressed into net dinucleotide counts (e.g.

Imperfect DNA mirror repeats in the gag gene of HIV-1 (HXB2) identify key functional domains and coincide with protein structural elements in each of the mature proteins.

Background: A DNA mirror repeat is a sequence segment delimited on the basis of its containing a center of symmetry on a single strand, e.g. 5'-GCATGGTACG-3'.

Cryopreservation of Picea sitchensis (sitka spruce) embryogenic suspensor masses.

A cryopreservation method comprising sorbitol pre-growth treatment, DMSO cryoprotection and two-step controlled rate cooling has been optimized for differentiated embryogenic suspensor masses (ESM) of Picea sitchensis. The protocol was applied to clonal cultures from five different half-sibling families each represented by five different genotypes and their responses to cryopreservation assessed over 3 years. Nineteen of the 25 clonal lines tested survived LN and were capable of regrowth and producing stage 2-4 somatic embryos.

Dynamics and structure of nickel chloride-methanol solutions: quasi-elastic neutron scattering and molecular dynamics simulations.

The high-resolution quasi-elastic neutron scattering (QENS) technique has been applied to study the translational diffusion of methanol protons in pure methanol (MeOH) at 223 and 297 K, and in 0.3 and 1.3 molal non-aqueous electrolyte solutions (NAESs) of NiCl in methanol at 297 K.

'Binge drinking? It's good, it's harmless fun': a discourse analysis of accounts of female undergraduate drinking in Scotland.

Binge drinking in young people, particularly females and students, is a source of some concern to those engaged in health education. The concept is usually defined in terms of quantities of alcohol consumed within a relatively short space of time. Research suggests that reasons for drinking are varied, and are likely to be influenced by culture and context.

A modified advanced Fenton process for industrial wastewater treatment.

For the first time hydrodynamic cavitation induced by a liquid whistle reactor (LWR) has been used in conjunction with the advanced Fenton process (AFP) for the treatment of industrial wastewater. Semi-batch experiments in the LWR were designed to investigate the performance of the process by optimising various parameters such as pressure, pH, H2O2 concentration and the concentration of industrial wastewater samples on the mineralisation of the total organic carbon (TOC). It was found that higher pressures are more favourable for a rapid TOC mineralisation.

Mineralisation of 2,4-dichlorophenoxyacetic acid by acoustic or hydrodynamic cavitation in conjunction with the advanced Fenton process.

The mineralisation of 2,4-dichlorophenoxyacetic acid (2,4-D) in the presence of zero-valent iron and hydrogen peroxide (the advanced Fenton process--AFP) whilst being subjected to acoustic or hydrodynamic cavitation is reported. If the reaction is merely stirred then there is 57% removal of TOC whilst on irradiation the figure is 64% although the latter reaction is more rapid. Use of ultrasound alone results in only 11% TOC removal in 60 min of treatment time.

Modelling nematode movement using time-fractional dynamics.

We use a correlated random walk model in two dimensions to simulate the movement of the slug parasitic nematode Phasmarhabditis hermaphrodita in homogeneous environments. The model incorporates the observed statistical distributions of turning angle and speed derived from time-lapse studies of individual nematode trails. We identify strong temporal correlations between the turning angles and speed that preclude the case of a simple random walk in which successive steps are independent.

Intensification of oxidation capacity using chloroalkanes as additives in hydrodynamic and acoustic cavitation reactors.

The effect of the presence and absence of the chloroalkanes, dichloromethane (CH(2)Cl(2)), chloroform (CHCl(3)) and carbon tetrachloride (CCl(4)) on the extent of oxidation of aqueous I(-) to I(3)(-) has been investigated in (a) a liquid whistle reactor (LWR) generating hydrodynamic cavitation and (b) an ultrasonic probe, which produces acoustic cavitation. The aim has been to examine the intensification achieved in the extent of oxidation due to the generation of additional free radicals/oxidants in the reactor as a result of the presence of chloroalkanes. It has been observed that the extent of increase in the oxidation reaction is strongly dependent on the applied pressure in the case of the LWR.

Treatment of industrial wastewater effluents using hydrodynamic cavitation and the advanced Fenton process.

For the first time, hydrodynamic cavitation induced by a liquid whistle reactor (LWR) has been used in conjunction with the advanced Fenton process (AFP) for the treatment of real industrial wastewater. Semi-batch experiments in the LWR were designed to investigate the performance of the process for two different industrial wastewater samples. The effect of various operating parameters such as pressure, H2O2 concentration and the initial concentration of industrial wastewater samples on the extent of mineralization as measured by total organic carbon (TOC) content have been studied with the aim of maximizing the extent of degradation.

Evaluation of the 1-methyl-2-phenylindole colorimetric assay for aldehydic lipid peroxidation products in plants: malondialdehyde and 4-hydroxynonenal.

The 1-methyl-2-phenylindole colorimetric assay is considered specific for malondialdehyde (MDA) and 4-hydroxynonenal (HNE) in mammalian systems, but its specificity in plant tissues is unknown. This study demonstrates that the assay produces a purple/blue chromophore with an absorbance peak at 586 nm for a malondialdehyde standard, while aqueous extractions from Ribes spp. Beta vulgaris, and Lycopersicon esculentum tissues produce an orange chromophore with an absorbance maximum at 450 nm and a large shoulder that extends to 700 nm.