Hatch-period-dependent early growth and survival of Pacific herring Clupea pallasii in Miyako Bay, Japan.

Considerable interannual variation in the abundance of larval and juvenile Pacific herring Clupea pallasii was detected in Miyako Bay, on the Pacific coast of northern Japan; abundances were high in 2001 and 2003 and low in 2000 and 2002. Hatch dates and growth rates for larval and juvenile survivors were estimated through otolith analysis. Water temperature and food availability were monitored on the spawning and nursery grounds in the inner part of the bay. The number of spawning females caught in nets set around the spawning ground was recorded during each spawning season (January to May) in 2000-2003. No correlation was found between the number of spawning females and the abundance of larvae and juveniles on the spawning and nursery grounds. The hatch dates of surviving larvae and juveniles were concentrated at the end of the spawning season in 2001 and in the middle of the season in 2003. The larvae experienced relatively high prey concentrations during the first-feeding period in 2001 but low concentrations in 2003. Survival of larvae during the first-feeding period may be a function of prey concentration as well as water temperature. In 2003, low water temperature would reduce starvation mortality during the first-feeding period. In contrast, unfavourable feeding conditions with higher temperatures during the first-feeding period seemed to result in low larval survival in 2000 and 2002. The 2001 larvae grew faster than those in 2003 because of the late hatch dates and the higher ambient temperatures that resulted. Temperature might be a major factor controlling growth rates of C. pallasii larvae in Miyako Bay.

[Transitory decreases in skin temperature during temperature increase training: possible explanation].

During biofeedback training, skin temperature changes were analyzed. Ten male undergraduates were asked to increase the temperature of the right index finger under three conditions: rest instructions with simulation feedback (Rest-SF), response-specific instructions without feedback (RI-NF), and response-specific instructions with feedback (RI-F). Skin temperature decreases during the early trials under the RI-F condition continued longer than under the RI-NF condition. Recovery from temperature decreases occurred faster after the repetition of feedback sessions. Skin temperature decreases were not observed under the Rest-SF condition. These results suggest that skin temperature decreases during early training associated with response-specific instructions, feedback, and the novelty of training. The results were also discussed in terms of the techniques which could increase skin temperature.

[Effects of feedback and changing criterion on the control of skin temperature].

Effects of feedback and changing criterion procedure on the skin temperature control and cognitive events (motivation, perceived control of skin temperature, and sensations accompanied with autogenic training) during an autogenic training (AT) were examined. Fifteen male students, five of each, were assigned to either AT with feedback under a fixed criterion (AT-FC), AT with feedback under a changing criterion (AT-CC), or AT without feedback (AT-NF) groups. Subjects were asked to increase the temperature of the right index finger using the AT in 12 training sessions. The criterion of feedback was fixed in the AT-FC group while it was increased in the AT-CC group when the temperature had satisfied the criterion in the previous session. Feedback had no effect on the performance of skin temperature control. However, it functioned as a cue for the judgement of performance and weakened the feeling of heaviness of the limbs. Changing criterion improved the performance gradually and increased the perceived efficacy of AT. These results suggested that the arousal elicited by feedback stimuli might suppress the feedback effect, and that the criterion could control the pattern of skin temperature change.

Effects of feedback on the control of skin temperature using the tension-relaxation experiment.

The effects of feedback on the control of peripheral skin temperature were examined using a tension-relaxation experiment. Sixteen male undergraduates were assigned to feedback or no-feedback groups and asked to increase the temperature of the right index finger immediately after decreasing with (in the feedback group) or without (in the no-feedback group) feedback during 10 training sessions. A no-feedback transfer session (post-test) followed these sessions. During the training sessions, skin temperature corresponded to instructions in the feedback group, whereas it did not in the no-feedback group. Feedback control did not transfer to the no-feedback condition. These results were discussed in terms of the ceiling-effect hypothesis in the baseline-relaxation type experiment and of the subjects' cognitive events, including strategies.