With an Ear up Against the Wall: An Update on Mechanoperception in Arabidopsis.

Cells interpret mechanical signals and adjust their physiology or development appropriately. In plants, the interface with the outside world is the cell wall, a structure that forms a continuum with the plasma membrane and the cytoskeleton. Mechanical stress from cell wall damage or deformation is interpreted to elicit compensatory responses, hormone signalling, or immune responses. Our understanding of how this is achieved is still evolving; however, we can refer to examples from animals and yeast where more of the details have been worked out. Here, we provide an update on this changing story with a focus on candidate mechanosensitive channels and plasma membrane-localized receptors.

The Natural History of Uncertainty

Chapter 4 describes the natural history of medical uncertainty—that is, the way that the phenomenon is manifest in people’s lives. It classifies people’s psychological responses to uncertainty within two main categories: primary (initial cognitive, emotional, and behavioral responses) and secondary (compensatory responses aimed at regulating primary responses). It presents a conceptual framework that classifies the variety of primary and secondary responses to uncertainty and discusses how the framework can help clinicians and patients evaluate and manage these responses. The ultimate goal of this framework is practical: to improve the management of uncertainty in medicine. The framework can promote this goal by enabling clinicians and patients to rise above their own regulatory responses to uncertainty and achieve greater tertiary control over them.

Compensation of Wild Plants Weakens the Effects of Crop-Wild Gene Flow on Wild Rice Populations

Crop-wild gene flow may alter the fitness of the recipient i.e., crop-wild hybrids, then potentially impact wild populations, especially for the gene flow carrying selective advantageous crop alleles, such as transgenes conferring insect resistance. Given the continuous crop-wild gene flow since crop domestication and the occasionally stressful environments, the extant wild populations of most crops are still “wild.” One interpretation for this phenomenon is that wild populations have the mechanism buffered for the effects of crop alleles. However, solid evidence for this has been scarce. We used wild rice (Oryza rufipogon) and transgenic (Bt/CpTI) rice (O. sativa) as a crop-wild gene flow model and established cultivated, wild, and F7 hybrid rice populations under four levels of insect (Chilo suppressalis) pressure. Then, we measured the trait performance of the plants and estimated fitness to test the compensatory response of relatively high fitness compared to the level of insect damage. The performance of all plants varied with the insect pressure level; wild plants had higher insect-tolerance that was expressed as over- or equal-compensatory responses to insect damage, whereas crop and hybrids exhibited under-compensatory responses. The higher compensation resulted in a better performance of wild rice under insect pressure where transgenes conferring insect resistance had a somewhat beneficial effect. Remarkable hybrid vigour and the benefit effect of transgenes increased the fitness of hybrids together, but this joint effect was weakened by the compensation of wild plants. These results suggest that compensation to environmental stress may reduce the potential impacts of crop alleles on wild plants, thereby it is a mechanism maintaining the “wild” characteristics of wild populations under the scenario of continuous crop-wild gene flow.

Compensatory Responses to Formant Perturbations Proportionally Decrease as Perturbations Increase

Purpose We continuously monitor our speech output to detect potential errors in our productions. When we encounter errors, we rapidly change our speech output to compensate for the errors. However, it remains unclear whether we adjust the magnitude of our compensatory responses based on the characteristics of errors. Method Participants ( N = 30 adults) produced monosyllabic words containing /ɛ/ (/hɛp/, /hɛd/, /hɛk/) while receiving perturbed or unperturbed auditory feedback. In the perturbed trials, we applied two different types of formant perturbations: (a) the F1 shift, in which the first formant of /ɛ/ was increased, and (b) the F1–F2 shift, in which the first formant was increased and the second formant was decreased to make a participant's /ɛ/ sound like his or her /æ/. In each perturbation condition, we applied three participant-specific perturbation magnitudes (0.5, 1.0, and 1.5 ɛ–æ distance). Results Compensatory responses to perturbations with the magnitude of 1.5 ɛ–æ were proportionally smaller than responses to perturbation magnitudes of 0.5 ɛ–æ. Responses to the F1–F2 shift were larger than responses to the F1 shift regardless of the perturbation magnitude. Additionally, compensatory responses for /hɛd/ were smaller than responses for /hɛp/ and /hɛk/. Conclusions Overall, these results suggest that the brain uses its error evaluation to determine the extent of compensatory responses. The brain may also consider categorical errors and phonemic environments (e.g., articulatory configurations of the following phoneme) to determine the magnitude of its compensatory responses to auditory errors.