18 research outputs found

    Does training with amplitude modulated tones affect tone-vocoded speech perception?

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    Temporal-envelope cues are essential for successful speech perception. We asked here whether training on stimuli containing temporal-envelope cues without speech content can improve the perception of spectrally-degraded (vocoded) speech in which the temporal-envelope (but not the temporal fine structure) is mainly preserved. Two groups of listeners were trained on different amplitude-modulation (AM) based tasks, either AM detection or AM-rate discrimination (21 blocks of 60 trials during two days, 1260 trials; frequency range: 4Hz, 8Hz, and 16Hz), while an additional control group did not undertake any training. Consonant identification in vocoded vowel-consonant-vowel stimuli was tested before and after training on the AM tasks (or at an equivalent time interval for the control group). Following training, only the trained groups showed a significant improvement in the perception of vocoded speech, but the improvement did not significantly differ from that observed for controls. Thus, we do not find convincing evidence that this amount of training with temporal-envelope cues without speech content provide significant benefit for vocoded speech intelligibility. Alternative training regimens using vocoded speech along the linguistic hierarchy should be explored

    The performance of stochastic designs in wellbore drilling operations

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    © 2018, The Author(s). Wellbore drilling operations frequently entail the combination of a wide range of variables. This is underpinned by the numerous factors that must be considered in order to ensure safety and productivity. The heterogeneity and sometimes unpredictable behaviour of underground systems increases the sensitivity of drilling activities. Quite often the operating parameters are set to certify effective and efficient working processes. However, failings in the management of drilling and operating conditions sometimes result in catastrophes such as well collapse or fluid loss. This study investigates the hypothesis that optimising drilling parameters, for instance mud pressure, is crucial if the margin of safe operating conditions is to be properly defined. This was conducted via two main stages: first a deterministic analysis—where the operating conditions are predicted by conventional modelling procedures—and then a probabilistic analysis via stochastic simulations—where a window of optimised operation conditions can be obtained. The outcome of additional stochastic analyses can be used to improve results derived from deterministic models. The incorporation of stochastic techniques in the evaluation of wellbore instability indicates that margins of the safe mud weight window are adjustable and can be extended considerably beyond the limits of deterministic predictions. The safe mud window is influenced and hence can also be amended based on the degree of uncertainty and the permissible level of confidence. The refinement of results from deterministic analyses by additional stochastic simulations is vital if a more accurate and reliable representation of safe in situ and operating conditions is to be obtained during wellbore operations.Published versio

    Microbial Responses to \u3ci\u3eIn Situ\u3c/i\u3e Chemical Oxidation, Six-Phase Heating, and Steam Injection Remediation Technologies in Groundwater

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    The evaluation of microbial responses to three in situ source removal remedial technologies— permanganate-based in situ chemical oxidation (ISCO), six-phase heating (SPH), and steam injection (SI)—was performed at Cape Canaveral Air Station in Florida. The investigation stemmed from concerns that treatment processes could have a variety of effects on the indigenous biological activity, including reduced biodegradation rates and a long-term disruption of community structure with respect to the stimulation of TCE (trichloroethylene) degraders. The investigation focused on the quantity of phospholipid fatty acids (PLFAs) and its distribution to determine the immediate effect of each remedial technology on microbial abundance and community structure, and to establish how rapidly the microbial communities recovered. Comprehensive spatial and temporal PLFA screening data suggested that the technology applications did not significantly alter the site’s microbial community structure. The ISCO was the only technology found to stimulate microbial abundance; however, the biomass returned to predemonstration values shortly after treatment ended. In general, no significant change in the microbial community composition was observed in the SPH or SI treatment areas, and even small changes returned to near initial conditions after the demonstrations

    Zataria multiflora Bioss: lethal effects of methanolic extract against protoscoleces of Echinococcus granulosus

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    The present study was aimed to evaluate the lethal effects of Zataria multiflora Boiss (Lamiaceae) methanolic extract against Echinococcus granulosus protoscoleces. Protoscoleces were aseptically aspirated from sheep livers having hydatid cysts. Various concentrations of the essential oil (2.5�20 mg/mL) were used for 10�60 min. Viability of protoscoleces was confirmed using eosin exclusion test (0.1 eosin staining). Obtained results showed that Z. multiflora extract at the concentration of 20 mg/mL after 10 min of exposure killed 100 protoscoleces. The mean of mortality rate of protoscoleces after 20 min of exposure to the concentration of 10 mg/mL was also 100 . Lower concentrations of Z. multiflora extract provoked a delayed protoscolicidal activity. The findings indicated potential of Z. multiflora methanolic extract as a natural source for the producing of new scolicidal agent for use in hydatid cyst surgery. © 2015, Indian Society for Parasitology
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