. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 306 M. (CAVALIERS AND OSSENKOPP. 1830 2200 Time [hr] Figure 3. Examples of daytime, nighttime and twilight period thermal (40°C) response latencies (no- ciceptive responses) of Cepaea nemoralis held under natural summer (August) outdoor (Environmental Sciences Center. London. Ontario. 43° 4' 30" and 8P 18' 30" W) light conditions and exposed to either a 60 Hz magnetic field ( gauss, rms. as described in Fig. 2) or a sham magnetic field (sham). Each point shown represents the mean nociceptive response of 1
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 306 M. (CAVALIERS AND OSSENKOPP. 1830 2200 Time [hr] Figure 3. Examples of daytime, nighttime and twilight period thermal (40°C) response latencies (no- ciceptive responses) of Cepaea nemoralis held under natural summer (August) outdoor (Environmental Sciences Center. London. Ontario. 43° 4' 30" and 8P 18' 30" W) light conditions and exposed to either a 60 Hz magnetic field ( gauss, rms. as described in Fig. 2) or a sham magnetic field (sham). Each point shown represents the mean nociceptive response of 18-24 snails. Different groups of snails were tested on each of the four days shown. For ease ot presentation standard errors are excluded. Exposure to the 60 Hz magnetic fields had no significant effects on the daytime (pre-sunset) nociceptive responses, but significantly (P < repeated measures analysis of variance for 2200 h) reduced the night- time response latencies as compared to the sham exposed snails and other control animals (not shown). Exposure to the magnetic fields also significantly (P < , for 2000 and 2100 h) attenuated the marked increases in thermal response latencies that occurred during the decreasing light levels of the twilight periods [civil (c), nautical (n) and astronomical (a) twilights; defined by the sun at -6°, -12° and -18°, respectively, from the horizon]. The greatest effects of the 60 Hz magnetic field on nociceptive responses occurred during the nautical and astronomical portions of the twilight period. The temperatures and light intensities that the snails were exposed to ranged from 22 to 28°C and 100 to 200 /jw/cm2 (20-40 Mw/cm2 in the tubes) in the daytime, and from 14 to 22°C and to 10 Mw/cm2 ( ^w/cnr in the tubes) in the twilight transitions and nighttime. These light (tubes) and temperature values were similar to the conditions present in the natural habitat of the snails (Kavaliers, 1989b). The backgr
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
