Electrophysiological evidence for linear polarization sensitivity in the compound eyes of the stomatopod crustacean Gonodactylus chiragra

Gonodactyloid stomatopod crustaceans possess polarization vision, which enables them to discriminate light of different e-vector angle. Their unusual apposition compound eyes are divided by an equatorial band of six rows of enlarged, structurally modified ommatidia, the mid-band (MB). The rhabdoms of the two most ventral MB rows 5 and 6 are structurally designed for polarization vision. Here we show, with electrophysiological recordings, that the photoreceptors R1-R7 within these two MB rows in Gonodactylus chiragra are highly sensitive to linear polarized light of two orthogonal directions (PS=6.1). They possess a narrow spectral sensitivity peaking at 565 nm. Unexpectedly, photoreceptors within the distal rhabdomal tier of MB row 2 also possess highly sensitive linear polarization receptors, which are in their spectral and polarization characteristics similar to the receptors of MB rows 5 and 6. Photoreceptors R1-R7 within the remainder of the MB exhibit low polarization sensitivity (PS=2.3). Outside the MB, in the two hemispheres, R1-R7 possess medium linear polarization sensitivity (PS=3.8) and a broad spectral sensitivity peaking at around 500 nm, typical for most crustaceans. Throughout the retina the most distally situated UV-sensitive R8 cells are not sensitive to linear polarized light.

A bibliographic snapshot of the telemedicine citation literature

There appear to have been no previous literature-based or literature-oriented studies in telemedicine which have analysed raw citation data. Using a simple search strategy, the Web of Science was analysed up to the end of 2005 to give a snapshot of the field, and to identify matters which would need to be considered in larger scale bibliometric studies. Of the 3673 telemedicine documents retrieved, 2213 (60%) had been cited. Of 56,875 citation records, 32,460 unique citation formats were found. The most-cited paper, and the paper with the greatest annual citation rate, was Perednia and Allen's review article in JAMA, 1995. The two specialist telemedicine journals published 40% of all papers retrieved. In the general literature (i.e. excluding the two specialist journals) there were 1556 citations to their 1374 'citable' articles, apportioned in the ratio 76:24, almost exactly in accordance with the distribution of the articles themselves. However, each of the two specialist telemedicine journals cited itself in a proportion higher than its share of original articles, with an 'excess' of self-citations of 14% in the journal of Telemedicine and Telecare, and 19% in the Telemedicine journal and E-Health. Despite certain technical difficulties, there is considerable scope for bibliometric research in telemedicine.