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The ability of enterococci to form PEA in vitro was investigated on a test strain Fs 202 of species Ec. faecalis from cheese. 22 enterococcal strains were isolated from foodstuff: nine strains from cheese, three strains from minced pork, seven strains from carcasses of pigs, two strains from chicken carcasses and one strain from cattle carcasses. The enterococci were examined in a test medium with additives of L-phenylalanine, L-tyrosine and dextrose. The amount of formed PEA was measured in periods of 24 h in test strain Fs 202 using RP-HPLC. Simultaneously, the pH-value and the number of microbes were determined at start and 72 h. The tested strains formed maximal or significant PEA amounts in test medium at 30 °C incubation temperature in a period of 72 h. In the same period strains without PEA formation were detected. A regular and intensive PEA formation was found by six Ec. faecalis, five Ec. hirae and two Ec. faecium strains. Ec. faecium could form only moderate PEA amounts. Amine traces or no PEA at all were detected for one Ec. faecium strain, three Ec. durans strains, two Ec. gallinarum strains and one Ec. casseliflavus strain. Potential starter organisms or probiotic strains should be tested in vitro at 30 °C for 72 hours for ability to form PEA. For toxicological reasons, it is important that those strains not have any ability to form PEA.  相似文献   
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Although observational learning by children may occur through imitating a modeler's actions, it can also occur through learning about an object's dynamic affordances- a process that M. Tomasello (1996) calls "emulation." The relative contributions of imitation and emulation within observational learning were examined in a study with 14- to 26-month-old children. The effectiveness of a "ghost" condition, in which the effective operation of the means apparatus was seen to occur without human agency, was compared with that of a standard modeling procedure in which the child saw an experimenter demonstrate the means action. The ghost condition was as likely to encourage observational learning as was the modeling condition; indeed, performance in the ghost condition was significantly better. The role of emulation in the development of observational learning is discussed in the context of a possible form of goal directedness without agency. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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Triangle tests were used to detect possible differences in the aroma of subcutaneous fat of growing pigs receiving de-oiled herring offal silage as a protein supplement at high (HS) and medium (MS) levels, i.e. at levels of 150 and 75 kg t?1 dry matter (DM), when compared with samples from matched controls. Tests were carried out on samples from pigs slaughtered at 60 and 90 kg. Statistically significant differences in the aroma of subcutaneous fat were detected at both feeding levels (HS and MS) and at each slaughter weight (60 and 90 kg). Correct identification of the odd samples was 60% in pigs slaughtered at 60 kg at both feeding levels. At 90 kg slaughter weight, there were 56 and 76% correct identifications at HS and MS levels, respectively. Paired Comparison (Preference) tests were used to determine if such differences were associated with flavour defects and consequent loss of palatability. Roasted pork joints and pork/rusk loaves from HS and MS pigs were compared with matched controls (HC and MC). As a result of these tests it was concluded that detectable differences from controls in aroma of subcutaneous fat in samples from HS and MS pigs were not associated with alteration in consumer preference for cooked meats. There was no evidence of taint in meats from either HS or MS groups.  相似文献   
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Emotional stimuli have been shown to elicit increased perceptual processing and attentional allocation. The late positive potential (LPP) is a sustained P300-like component of the event-related potential that is enhanced after the presentation of pleasant and unpleasant pictures as compared with neutral pictures. In this study, the LPP was measured using dense array electroencephalograph both before and after pleasant, neutral, and unpleasant images to examine the time course of attentional allocation toward emotional stimuli. Results from 17 participants confirmed that the LPP was larger after emotional than neutral images and that this effect persisted for 800 ms after pleasant picture offset and at least 1,000 ms after unpleasant picture offset. The persistence of increased attention after unpleasant compared to pleasant stimuli is consistent with the existence of a negativity bias. Overall, these results indicate that attentional capture of emotion continues well beyond picture presentation and that this can be measured with the LPP. Implications and directions for future research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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Because of the nature of the water cycle in Berlin, a number of persistent wastewater residues are present in the surface water and may potentially reach the groundwater via bank filtration and artificial recharge. The occurrence and behaviour of the wastewater residues para-toluenesulphonamide (p-TSA), ortho-toluenesulphonamide (o-TSA) and benzenesulphonamide (BSA) through wastewater treatment, surface water, bank filtration and drinking water treatment was studied. In addition, groundwater below a former sewage farm was investigated. All three compounds are ubiquitous in the aquatic environment of Berlin. p-TSA concentrations are much higher than those of o-TSA and BSA. p-TSA was found in high concentrations in the wastewater influent (2 to 15microg/L), in the wastewater effluent (<0.15 to 2.34microg/L) and in sewage farm groundwater (<0.05 to 20microg/L) and in lower concentrations in the surface water (<0.05 to 1.15microg/L), bank filtrate (<0.05 to 0.30microg/L) and drinking water (<0.05 to 0.54microg/L). p-TSA is considerably depleted during waste- and drinking water treatment ( approximately 90% reduction each). The concentration ranges for o-TSA and BSA in wastewater influents were 0.11 to 8microg/L and <0.05 to 0.64microg/L, respectively, while the values for wastewater effluents were 0.14 to 4microg/L for o-TSA and 0.25 to 0.49microg/L for BSA. Wastewater treatment and drinking water treatment do not reduce the concentrations of o-TSA and BSA. The behaviour of o-TSA during wastewater treatment varies largely between different wastewater treatment plants where concentrations increase, remain constant or decrease. BSA forms during treatment. The concentrations measured in surface water, sewage farm groundwater, bank filtrate and drinking water were <0.05 to 1.74microg/L for o-TSA and <0.05 to 0.53microg/L for BSA.  相似文献   
49.
This paper studies the problem of finding the minimum cost curvature-constrained path between two directed points where the cost at every point along the path depends on the instantaneous direction. This generalises the results obtained by Dubins for curvature-constrained paths of minimum length, commonly referred to as Dubins paths. We show that there always exists a path of the form $\mathcal {C}\mathcal {S}\mathcal {C}\mathcal {S}\mathcal {C}$ or a degeneracy which is optimal, where $\mathcal {C}$ represents an arc of maximum curvature, and $\mathcal {S}$ represents a straight line. This result is also extended to the case where there is not only a directional-cost, but the cost of curved sections are scaled up by a factor w C ≥1. The results obtained can be applied to optimising the development of underground mine networks, where the paths need to satisfy a curvature constraint, the cost of development of the tunnel depends on the direction due to the geological characteristics of the ground, and curved sections may incur more cost due to additional support and ventilation.  相似文献   
50.
The IDH1R132H mutation in glioma results in the neoenzymatic function of IDH1, leading to the production of the oncometabolite 2-hydroxyglutarate (2-HG), alterations in energy metabolism and changes in the cellular redox household. Although shifts in the redox ratio NADPH/NADP+ were described, the consequences for the NAD+ synthesis pathways and potential therapeutic interventions were largely unexplored. Here, we describe the effects of heterozygous IDH1R132H on the redox system in a CRISPR/Cas edited glioblastoma model and compare them with IDH1 wild-type (IDH1wt) cells. Besides an increase in 2-HG and decrease in NADPH, we observed an increase in NAD+ in IDH1R132H glioblastoma cells. RT-qPCR analysis revealed the upregulation of the expression of the NAD+ synthesis enzyme nicotinamide phosphoribosyltransferase (NAMPT). Knockdown of NAMPT resulted in significantly reduced viability in IDH1R132H glioblastoma cells. Given this dependence of IDH1R132H cells on NAMPT expression, we explored the effects of the NAMPT inhibitors FK866, GMX1778 and GNE-617. Surprisingly, these agents were equally cytotoxic to IDH1R132H and IDH1wt cells. Altogether, our results indicate that targeting the NAD+ synthesis pathway is a promising therapeutic strategy in IDH mutant gliomas; however, the agent should be carefully considered since three small-molecule inhibitors of NAMPT tested in this study were not suitable for this purpose.  相似文献   
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