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We investigated whether stimulus‐processing in sensory or semantic memory influenced affective responses after repeated exposures. This entailed exploring whether activating sensory memory by comparing odor strength during exposure (Experiments 1 and 3) or activating semantic memory by naming the odor during exposure (Experiments 2 and 4) changed affective responses to the odor. Generally pleasant or generally unpleasant odors were presented to participants 40 times (Experiments 1 and 2) or 10 times (Experiments 3 and 4), and their liking for the odor was rated before and after the exposure. Results indicated that affective responses to odors became neutral after 40 exposures, regardless of processing the odor in sensory or semantic memory during the exposure. The liking score changed only for likable odors after 10 exposures, when the odor was processed in sensory memory (bottom‐up processing) during the exposure. These findings suggest that affective responses change through repeated exposure, regardless of the type of stimulus processing. However, the repeated exposure effect differed based on the stimulus‐processing type during the exposure, when the number of exposures was limited. [ABSTRACT FROM AUTHOR]

Background: Helicobacter pylori has a high infection rate, and it is possible that more than half of the world's population is infected. The route of transmission of H. pylori has not been completely elucidated yet. The coccoid form of H. pylori is generally considered to be in a VBNC (viable but nonculturable) state, and this form in the environment is thought to play an important role in infection and transmission, but its stability and survivability are still unknown. Materials and methods: In order to promote its changing to coccoid form, the spiral form of H. pylori grown in a culture medium was exposed to sterile distilled water, and we investigated the bacterial cell number and the morphological changes by using fluorescence staining methods and electron microscopic observation. We also examined the dynamics of its growth ability by measuring the colony forming unit on an agar‐plate medium. Results: After exposure to sterile distilled water, the H. pylori spiral form rapidly lost its growth ability at 37°C. One day after exposure, approximately 95% of the spiral form disappeared and the proportion of the coccoid form increased. The total number of bacteria also decreased to less than half and continued to decrease over time. Epi‐microscopic and electron microscopic observations revealed that deformation of bacterial cells, collapse, and leaking out of cell contents were promoted in exposure to sterile distilled water. Conclusion: Helicobacter pylori quickly begins to transform into the coccoid form after exposure to sterile distilled water, rapidly loses its growth ability, and then lyses and dies. Water‐exposure is lethal for H. pylori and it is unlikely to survive in the VBNC state in water. [ABSTRACT FROM AUTHOR]

Corynebacterium ulcerans is a rod-shaped, aerobic, gram-positive bacterium closely related to C. diphtheria. Some strains of C. ulcerans can produce diphtheria toxin, which causes respiratory diphtheria in humans and animals. [...]