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Thermal Requirements (thermal + requirement)
Selected AbstractsThe Effect of Male Incubation Feeding, Food and Temperature on the Incubation Behaviour of New Zealand RobinsETHOLOGY, Issue 6 2010Rebecca L. Boulton Because of finite resources, organisms face conflict between their own self-care and reproduction. This conflict is especially apparent in avian species with female-only incubation, where females face a trade-off between time allocated to their own self-maintenance and the thermal requirements of developing embryos. We recorded incubation behaviour of the New Zealand robin (Petroica longipes), a species with female-only incubation, male incubation feeding and high nest predation rates. We examined how male incubation feeding, ambient temperature and food availability (invertebrate biomass) affected the different components of females' incubation behaviour and whether incubation behaviour explained variation in nest survival. Our results suggest that male incubation feeding rates of 2.8 per hour affect the female's incubation rhythm by reducing both on- and off-bout duration, resulting in no effect on female nest attentiveness, thus no support for the female-nutritional hypothesis. The incubation behaviours that we measured did not explain nest survival, despite high nest predation rates. Increased ambient temperature caused an increase in off-bout duration, whereas increased food availability increased on-bout duration. While males play a vital role in influencing incubation behaviour, female robins attempt to resolve the trade-off between their own foraging needs and the thermal requirements of their developing embryos via alternating their incubation rhythm in relation to both food and temperature. [source] Study on a reversible thermal panel for spacecraft (detailed design based on parametric studies and experimental verification)HEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 7 2006Hosei Nagano Abstract This paper describes a new passive thermal control device,a Reversible Thermal Panel (RTP), which changes its function reversibly from a radiator to solar absorber by deploying/stowing the radiator/absorber reversible fin. Parametric studies were conducted and the RTP configuration which satisfies the thermal requirements was determined. The RTP engineering model was fabricated using highly oriented graphite sheets, honeycomb base plate, and shape memory alloy. The heat rejection performances and autonomous thermal controllability were evaluated by thermal vacuum tests. The test results show the excellent performances of heat rejection, absorption, and autonomous thermal control for the RTP. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(7): 464,481, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20131 [source] Control of summer and winter diapause in the leaf-mining fly Pegomyia bicolor Wiedemann (Dipt., Anthomyiidae)JOURNAL OF APPLIED ENTOMOLOGY, Issue 4 2001Effects of photoperiod and temperature on diapause induction and termination were investigated in both aestival and hibernal pupae of Pegomyia bicolor Wiedemann under field and laboratory conditions. In the field, summer diapause had occurred already in part of the first pupal population; the proportion of diapause gradually rose as the day length and temperature increased. This fly is a short-day species with a pupal summer and winter diapause. Summer diapause was induced by both long day-lengths and mild temperatures. The whole larval life is sensitive to photoperiod. Winter diapause was induced mainly by low temperatures, especially in the first 10 days after pupation. High temperatures strongly enhanced summer diapause induction regardless of photoperiod. The diapause-averting influence of short photoperiods was fully expressed only at moderately low temperatures. High temperatures delayed diapause development, resulting in a rather long summer diapause; whereas low temperatures hastened it, leading to a short winter diapause and showing a low thermal threshold for diapause development. In the field, the post-diapause development started in January, the coldest month, suggesting that the thermal requirements for post-diapause development is also low. [source] Photoperiodic and temperature control of nymphal development and induction of reproductive diapause in two predatory Orius bugs: interspecific and geographic differencesPHYSIOLOGICAL ENTOMOLOGY, Issue 4 2008DMITRY L. MUSOLIN Abstract The effects of day-length and temperature on pre-adult growth and induction of reproductive diapause are studied in Orius sauteri and Orius minutus (Heteroptera: Anthocoridae) from northern (43.0°N, 141.4°E) and central (36.1°N, 140.1°E) Japan. In the north, at 20 °C, pre-adult growth is slower under an LD 14 : 10 h photoperiod than under shorter or longer photophases. At 24 and 28 °C, the longer photophases result in shorter pre-adult periods. Acceleration of nymphal growth by short days in autumn appears to be adaptive. In the central region, this response is less pronounced, suggesting that timing of adult emergence is less critical than in the north. Day length also influences the thermal requirements for pre-adult development. The slope of the regression line representing temperature dependence of pre-adult development is significantly smaller and the lower development threshold (LDT) is significantly lower under an LD 12 : 12 h photoperiod than under long-day conditions. The weaker dependence of nymphal growth on temperature and the lower LDT in autumn might be adaptive. In the north, increased temperature shifts the critical day length of diapause induction and suppresses the photoperiodic response in O. sauteri but not in O. minutus. Further south, the incidence of diapause in both species is low even under short-day conditions but the same interspecific difference is observed (i.e. increase of temperature affects the response in O. sauteri but not in O. minutus). This suggests seasonally earlier diapause induction with weaker temperature dependence in O. minutus than in O. sauteri. [source] | ||||||||||