파밤나방(Spodoptera exigua)의 발육을 일으키는 최저온도를 결정하고, 이 상태의 생리적 특성을 서로 다른 기능군(대사, 신경, 면역 및 스트레스) 유전자의 발현 양상을 이해하기 위해 본 연구를 수행하였다. 알부터 번데기까지 파밤나방의 발육영점온도는 5.5~11.6℃로 다양하였다. 유충은 알과 번데기에 비해 비교적 낮은 온도에서 발육이 가능하였다. 5령충의 경우 생리적 발육영점온도가 추정치(10.3℃)와 다르게 이보다 높은 15℃에서 관찰되었다. 정량적 RT-PCR로 분석된 유전자의 발현양상은 유충 영기가 진행됨에 따라 모든 기능군의 대부분 유전자의 발현량이증가하였고, 또한 5령 시기에서도 처리온도가 증가함에 따라 이들 유전자의 발현량도 증가하였다. 비록 동일한 갓 탈피한 5령이라 하더라도 이전에 노출된 외부 온도에 따라 발현량이 상이하였다. 5령충의 생리적 발육영점온도인 15℃에서 대부분의 유전자 발현량은 저하되었다. 그러나 높은 온도에서와 마찬가지로 발육기간이 증가함에 따라 이들 유전자의 발현량이 증가하였다. 이상의 결과는 발육영점온도에서 파밤나방의 발육 관련 유전자의 발현이 전체적으로 수준은 낮지만 지속적으로 진행되고 있다는 것을 의미한다.

Many insects overwinter in diapause in the temperate region. Winter diapause often terminates far yearly than our thought, eg. Many in December. After diapause termination, insect becomes in quiescence. The lower developmental threshold of overwintering Oriental fruit moth larvae is in the range of 7.5-8.4℃ depending on the geographic location. We have determined the developmental period of overwintering OFM larvae from the time series interval collection. Collections were made from mid Jan to late March at 10d interval. Collected larvae were held in a cold chamber at 6°C for 5 days, and then subjected at 20°C with 75% R.H., 16:8(L:D).hr. The developmental period from overwintering cocooned larvae to adults was longest in mid. January collections, became shorter after 31 Jan. collection, then gradually decreased until mid March. Cocooned larvae developmental period became shorter after 31 Jan. while that of pupae became shorter after 20 Feb. During this study, female ratio was not different to 0.5. Mortality of winter collected larvae to adults was 45% including 30% parasitism. Partial explanation of the insect development under the lower developmental threshold was discussed; limitation of linear model estimation, temperature data quality and physiological metabolism after diapause termination. From January to February, daily average temperature fluctuated but under the lower developmental threshold. However, daily maximum temperature became noticeably higher than the lower developmental threshold after 20 Jan. However, this result indicates that after late Jan, physiological state of OFM is altered.

Temperature dependency of resistivity of the carbon black-polyethylene composites below and above percolation threshold is studied based on the electrical conduction mechanism. Temperature coefficient of resistance of the composites below percolation threshold changed from minus to plus, increasing volume fraction of carbon black; this trend decreased with increasing volume fraction of carbon black. The temperature dependence of resistivity of the composites below percolation threshold can be explained with a tunneling conduction model by incorporating the effect of thermal expansion of the composites into a tunneling gap. Temperature coefficient of resistance of the composites above percolation threshold was positive and its absolute value increased with increasing volume fraction of carbon black. By assuming that the electrical conduction through percolating paths is a thermally activated process and by incorporating the effect of thermal expansion into the volume fraction of carbon black, the temperature dependency of the resistivity above percolation threshold has been well explained without violating the universal law of conductivity. The apparent activation energy is estimated to be 0.14 eV.