A teichuronopeptide (TUP) is one of major structural components of the cell wall of the facultative alkaliphilic strain Bacillus lentus C-125. A mutant defective in TUP synthesis grows slowly at alkaline pH. An upper limit of pH for growth of the mutant was 10.4, while that of the parental strain C-125 was 10.8. GenetupA, directing synthesis of TUP, was cloned from C-125 chromosomal DNA. The primary translation product of this gene is likely a cytoplasmic protein (57.3 kDa) consisting of 489 amino acid residues. Introduction of the tupA gene into the TUP-defective mutant complemented the mutation responsible for the pleiotropic phenotypes of the mutant, leading to simultaneous disappearance of the defect in TUP synthesis, the diminished ability for cytoplasmic pH homeostasis, and the low tolerance for alkaline conditions. These results demonstrate that the acidic polymer TUP in the cell wall plays a role in pH homeostasis in this alkaliphile.

The aim of this study was to examine impacts of cell phone conversation and operation on the driving performance.Ten male students participated in following two experiments: one is to examine the effect of cell phone conversation on driving performance, and the other is to examine the effect of cell phone operation while driving. In the former experiment, the subjects performed No-task and conversation (cognitive tasks) with hands-free (HF) and hand-held (HH) cell phone while driving in city traffic in which the maximum speed limit is 40 km/h. In the latter experiment, they were instructed to operate (dialing or talking) HH and HF such as touch screen, earphone, and voice recognition while driving. We measured driving performance, heart rate, eye tracking, and NASA-TLX. The results were as follows: (1) Regardless of phone type, cell phone conversation while driving increased the drivers' psychophysiological stress and also had negative impacts on the driving performance. (2) Break reaction time in response to pop-up event was significantly slower in operation of both HH and all hands-free kits than in No-task. The results suggest that using all hands-free cell phone while driving is not safer than hand-held cell phone or driving without a cell phone; inattentional blindness itself may be a risk factor for traffic accidents.

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