Ochratoxin A removal in synthetic media by living and heat-inactivated cells of Oenococcus oeni isolated from wines

The capacity of Oenococcus oeni to eliminate ochratoxin A (OTA) from synthetic media in different conditions was studied. Ten tested O. oeni strains removed OTA from the medium but with significant differences depending on the strain, incubation period, and initial OTA level in the medium. Mycotoxin reductions higher than 60% were recorded in 14-day cultures spiked with 2 μg OTA/l. Toxin removal was independent of bacterial viability and culture medium composition. This is the first study carried out to study OTA removal dynamics by living and heat-inactivated cells of O. oeni. The results aim that this bacterium may be a very useful tool to control OTA in food and beverages.     

The influence of lens material and lens wear on the removal and viability of Staphylococcus epidermidis

PURPOSE: The aim of this study was to evaluate the influence of lens material and lens wear on the removal capability of Staphylococcus epidermidis. Assessment of viability of remaining adhered bacteria was another goal of this work. Four silicone hydrogel materials (galyfilcon A, balafilcon A, lotrafilcon A, lotrafilcon B) and one conventional hydrogel material (etafilcon A) were assayed. METHODS: Detachment studies on S. epidermidis were carried out in a parallel plate flow chamber. Contact lenses (CLs) were fitted to the bottom of the flow chamber and a bacterial suspension was perfused into the system, promoting bacterial adhesion. Afterwards, detachment was stimulated using a multipurpose solution (MPS, ReNu Multiplus) and the percentage of removed bacteria estimated through microscopic observation and enumeration. Remaining adhered bacteria were stained with propidium iodide (PI) and enumerated in order to assess their viability. Additionally, the worn lenses were observed by confocal laser scanning microscopy (CLSM) to visualize bacterial distribution along the lens surfaces. RESULTS: Bacterial removal was significant (p<0.05) for both unworn and worn galyfilcon A and etafilcon A. Galyfilcon A exhibited a detachment percentage of 59.1 and 63.5 while etafilcon A of 62.6 and 69.3, both for unworn and worn lenses, respectively. As far as bacterial viability is concerned, it was found that worn lenses exhibit a superior amount of non-viable bacteria than unworn CLs. Images obtained by CLSM revealed an irregular bacterial distribution for all lens materials. CONCLUSIONS: It appears that surface and/or bulk structure of the lens material affects removal of S. epidermidis while CL wear influences their viability.     

Methane Oxidation Over Pd Supported on Ceria–Alumina Under Rich/Lean Cycling Conditions

Catalysts with highly dispersed palladium on alumina, alumina doped with 20 wt% ceria and ceria have been prepared, characterized and examined for net-lean methane oxidation. In particular, the activity and selectivity were investigated during rich/lean cycling of the feed. The ceria content is found to influence both the general and the instantaneous activity responses. The results indicate that the active phase of palladium changes between reduced and oxidised Pd during the rich/lean cycling, and that the process is influenced by the presence of ceria.     

Control of interference during working memory updating.

The current study examined the nature of the processes underlying working memory updating. In 4 experiments using the n-back paradigm, the authors demonstrate that continuous updating of items in working memory prevents strong binding of those items to their contexts in working memory, and hence leads to an increased susceptibility to proactive interference. Results of Experiments 1 and 2 show that this interference reflects a competition between a process that reveals the degree of familiarity of an item and a context-sensitive recollection process that depends on the strength of bindings in working memory. Experiment 3 further clarifies the origins of interference during updating by demonstrating that even items that are semantically related to the updated working memory contents but that have not been maintained in working memory before cause proactive interference. Finally, the results of Experiment 4 indicate that the occurrence of interference leads to top-down behavioral adjustments that prioritize recollection over familiarity assessment. The implications of these findings for the construct validity of the n-back task, for the control processes involved in working memory updating, and for the concept of executive control more generally are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transcriptome Analysis of High-Temperature Stress in Developing Barley Caryopses :Early Stress Responses and Effects on Storage Compound Biosynthesis

High-temperature stress,like any abiotic stress,impairs the physiology and development of plants,including the stages of seed setting and ripening.We used the Aflymetrix 22K Barley1 GeneChip microarray to investigate the response of developing barley(Hordeum vulgare)seeds,termed caryopses,after 0.5,3,and 6 h of heat stress exposure;958 induced and 1122 repressed genes exhibited spatial and temporal expression patterns that provide a detailed insight into the caryopses'early heat stress responses.Down-regulation of genes related to storage compound biosynthesis and cell growth provides evidence for a rapid impairment of the caryopsis' development.Increased levels of sugars and amino acids were indicative for both production of compatible solutes and feedback-induced accumulation of substrates for storage compound biosynthesis.Metadata analysis identified embryo and endosperm as primary locations of heat stress responses,indicating a strong impact of short-term heat stress on central developmental functions of the caryopsis.A comparison with heat stress responses in Arabidopsis shoots and drought stress responses in barley caryopses identified both conserved and presumably heat-and caryopsis-specific stress-responsive genes.Summarized,our data provide an important basis for further investigation of gene functions in order to aid an improved heat tolerance and reduced losses of yield in barley as a model for cereal crops.     

Motor alterations associated with exposure to manganese in the environment in Mexico

Overexposure to manganese (Mn) causes neurotoxicity (a Parkinson-like syndrome) or psychiatric damage ("manganese madness"). Several studies have shown alterations to motor and neural behavior associated with exposure to Mn in the workplace. However, there are few studies on the effects of environmental exposure of whole populations. We studied the risk of motor alterations in people living in a mining district in Mexico. We studied 288 individual people (168 women and 120 men) from eight communities at various distances from manganese extraction or processing facilities in the district of Molango. We measured manganese concentrations in airborne particles, water, soil and crops and evaluated the possible routes of Mn exposure. We also took samples of people's blood and determined their concentrations of Mn and lead (Pb). We used "Esquema de Diagnóstico Neuropsicológico" Ardila and Ostrosky-Solís's neuropsychological battery to evaluate motor functions. Concentrations of Mn in drinking water and maize grain were less than detection limits at most sampling sites. Manganese extractable by DTPA in soils ranged between 6 and 280 mg kg(-1) and means were largest close to Mn extraction or processing facilities. Air Mn concentration ranged between 0.003 and 5.86 microg/m(3); the mean value was 0.42 microg/m(3) and median was 0.10 microg/m(3), the average value (geometric mean) resulted to be 0.13 microg/m(3). Mean blood manganese concentration was 10.16 microg/l, and geometric mean 9.44 microg/l, ranged between 5.0 and 31.0 mcrog/l. We found no association between concentrations of Mn in blood and motor tests. There was a statistically significant association between Mn concentrations in air and motor tests that assessed the coordination of two movements (OR 3.69; 95% CI 0.9, 15.13) and position changes in hand movements (OR 3.09; CI 95% 1.07, 8.92). An association with tests evaluating conflictive reactions (task that explores verbal regulations of movements) was also found (OR 2.30; CI 95% 1.00, 5.28). It seems from our results that people living close to the manganese mines and processing plants suffer from an incipient motor deficit, as a result of their inhaling manganese-rich dust.