Host location and selection by the symbiotic sargassum crab Portunus sayi: the role of chemical, visual and tactile cues

The relative motion between the surface of an object and our fingers produces patterns of skin deformation such as stretch, indentation, and vibrations. In this study, we hypothesized that motion-induced vibrations are combined with other tactile cues for the discrimination of tactile speed. Specifically, we hypothesized that vibrations provide a critical cue to tactile speed on surfaces lacking individually detectable features like dots or ridges. Thus masking vibrations unrelated to slip motion should impair the discriminability of tactile speed, and the effect should be surface-dependent. To test this hypothesis, we measured the precision of participants in discriminating the speed of moving surfaces having either a fine or a ridged texture, while adding masking vibratory noise in the working range of the fast-adapting mechanoreceptive afferents. Vibratory noise significantly reduced the precision of speed discrimination, and the effect was much stronger on the fine-textured than on the ridged surface. On both surfaces, masking vibrations at intermediate frequencies of 64 Hz (65-μm peak-to-peak amplitude) and 128 Hz (10 μm) had the strongest effect, followed by high-frequency vibrations of 256 Hz (1 μm) and low-frequency vibrations of 32 Hz (50 and 25 μm). These results are consistent with our hypothesis that slip-induced vibrations concur to the discrimination of tactile speed.

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HOST LOCATION KNOWLEDGE SOURCING AND SUBSIDIARY INNOVATIVE PERFORMANCE — EXAMINING THE MODERATING ROLE OF ALTERNATIVE SOURCES OF KNOWLEDGE AND IPR DISTANCE

International Journal of Innovation Management ◽

10.1142/s1363919616500535 ◽

2016 ◽

Vol 20 (06) ◽

pp. 1650053

Author(s):

GEORGIOS BATSAKIS

Keyword(s):

Host Location ◽

Multinational Enterprise ◽

Knowledge Network ◽

Knowledge Sourcing ◽

Innovative Performance ◽

Sources Of Knowledge ◽

Alternative Sources ◽

The Relationship ◽

Moderating Role

This study investigates the relationship between the subsidiary’s external knowledge sourcing in the host network of operation and innovative performance, and the moderating role of (i) alternative sources of knowledge (those related to the internal and external home knowledge network) and (ii) Intellectual Property Rights (IPRs) distance between the host and the home location of the Multinational Enterprise (MNE). Based on a dataset comprising 170 R&D subsidiaries (classified by 57 parent companies and 23 host countries) it is shown that a curvilinear (inverted U-shaped) relationship exists between external host knowledge sourcing and innovative performance. In terms of the moderating effects, the findings reveal that the influence of alternative sources of knowledge affects the aforementioned relationship in a negative way. Finally, a stronger IPR protection regime in the host location weakens, rather than strengthens the relationship between the external host knowledge sourcing and innovative performance.

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