The Experts below are selected from a list of 807 Experts worldwide ranked by ideXlab platform

Kikukatsu Ito - One of the best experts on this subject based on the ideXlab platform.

  • exogenous induction of thermogenesis in arum concinnatum by salicylic acid
    Functional Plant Biology, 2018
    Co-Authors: Danae Laina, Roger S Seymour, Kikukatsu Ito, Ioanna Oikonomou, Konstantina Koutroumpa, Michael Bariotakis, Kiriakos Kotzabasis, Stergios Pirintsos
    Abstract:

    Arum concinnatum Schott is a highly thermogenic species, with the temperature of the appendix exceeding ~10.9°C above the ambient temperature during thermogenesis, whereas the rates of respiration of the male florets in intact inflorescences peak at 0.92μmol s-1 g-1, which is the highest rate so far measured among the plants. Here, we attempt the ex situ exogenous induction of thermogenesis in whole inflorescences and in separate appendices of the Spadix, and explore the thermogenic patterns under controlled laboratory conditions of light and temperature. Mature but unopened inflorescences and appendices showed thermogenic responses when treated with salicylic acid (SA), but not when treated with distilled water (control). With regard to light conditions, the responses revealed only one significant difference for inflorescences, which concerns the higher maximum temperature in the continuous light treatment compared with continuous dark. Along the ambient temperature gradient, at the lowest temperature edge individuals remained stable close to ambient temperature and to control. These findings suggest that, in general, ex situ exogenous induction of thermogenesis can be achieved in whole inflorescences and in separate appendices of Spadix of A. concinnatum using SA. This study also indicates that SA acts independently of light conditions, while exogenous induction of thermogenesis takes place within an ambient temperature range.

  • Modeling of thermoregulation in the skunk cabbage in relation to meteorological factors.
    Agricultural and Forest Meteorology, 2009
    Co-Authors: Ken Takahashi, Kikukatsu Ito, Takanori Ito, Shigeki Chiba, Hiroshi Osada
    Abstract:

    A model is proposed to calculate the Spadix temperature of the skunk cabbage Symplocarpus foetidus which regulates its internal temperature at around 20 °C during the female stage even when the ambient air temperature drops below freezing. The model is based on energy balance of the Spadix under field conditions. The input data are standard meteorological data and Spadix parameters. The model output was compared with experimental data collected under different climate conditions. The agreement between observed and calculated Spadix temperatures was fairly good.

  • Algorithm for Temperature Control in the Skunk Cabbage, Symplocarpus Foetidus
    Biotechnology & Biotechnological Equipment, 2008
    Co-Authors: K. Takahashi, Kikukatsu Ito, T. Ito, T. Endo, S. Chiba, Hiroshi Osada
    Abstract:

    ABSTRACTThis paper presents a temperature control algorithm for the Spadix of the skunk cabbage Symplocarpus foetidus, a plant which holds its Spadix temperature nearly constant. We derive the control algorithm from a proposed thermoregulation model of the Spadix of S. foetidus. In addition, we investigate the control algorithm of S. foetidus for general industrial applications from a control engineering perspective by running simulations and applying it to actual equipment. The temperature control algorithm responds to the rate of change of the controlled variable over time and adjusts the output of the controller as required to minimize the rate of change. The control algorithm of the Spadix of S. foetidus is robust to perturbations in the controlled object, and the control algorithm incorporated into a microprocessor successfully controls the performance of actual equipment.

  • Modeling of the thermoregulation system in the skunk cabbage: Symplocarpus foetidus.
    Physical review. E Statistical nonlinear and soft matter physics, 2007
    Co-Authors: Ken Takahashi, Yoshihiko Onda, Kikukatsu Ito, Takanori Ito, Shigeki Chiba, T. Endo, Hiroshi Osada
    Abstract:

    This paper presents a model of the thermoregulation system of the Spadix of skunk cabbage Symplocarpus foetidus which regulates its internal temperature at around 20 degrees C during flowering even when the ambient air temperature drops below freezing. From the temperature responses of the Spadix to changing ambient air temperature, we assumed that the thermoregulation system of the Spadix is probably one of negative feedback control. The feedback signals are based on the rate of temperature change of the Spadix over time. A signal is factored into the biochemical energy generator, and becomes biochemical energy, some of which becomes heat. Comparing our proposed model temperature responses and those of the living Spadix, we found good agreement. In the process of engineering the model, the existence of two regulatory pathways in the thermoregulation system was simulated, and our proposed model appears to provide the necessary elements to explain the fundamental mechanism of the thermoregulation system of S. foetidus.

  • Temperature-Triggered Periodical Thermogenic Oscillations in Skunk Cabbage (Symplocarpus foetidus)
    Plant & cell physiology, 2004
    Co-Authors: Kikukatsu Ito, Yoshihiko Onda, Takanori Ito, Matsuo Uemura
    Abstract:

    The natural occurrence of temperature-triggered and light-independent thermogenic oscillation in the Spadix of skunk cabbage, Symplocarpus foetidus, was discovered. The identified thermogenic oscillator had an accurate periodical cycle (ca. 60 min per cycle) that apparently responded to an increase or decrease in the Spadix temperature with a threshold of less than 0.9 degrees C. Neither a constant ambient air temperature nor transient changes in the ambient air temperature within 10 min (19 degrees C --> 15 degrees C --> 19 degrees C) induced the temperature oscillation in the Spadix. Moreover, the periodical cycles were independent of the weight of the Spadix (2.5-9.2 g) and the amplitudes of the temperature oscillations were correlated with the magnitude of the changes in the Spadix temperatures. These results imply that periodical temperature oscillations in the Spadix of S. foetidus possess a quantitative regulatory process that involves a temperature sensation and subsequent heat production. Based on these results, we propose a time-dependent thermogenic oscillatory model that acts as a precise thermal regulator under dynamic environmental temperature changes.

Yoshihiko Onda - One of the best experts on this subject based on the ideXlab platform.

  • Pyruvate-sensitive AOX exists as a non-covalently associated dimer in the homeothermic Spadix of the skunk cabbage, Symplocarpus renifolius
    FEBS letters, 2007
    Co-Authors: Yoshihiko Onda, Yasuko Ito-inaba, Megumi Ichikawa, Yoshiaki Kato, Kazushige Matsukawa, Yukie Abe, Takanori Ito, Miyuki Morohashi, Yuka Ito, Minoru Otsuka
    Abstract:

    The cyanide-resistant alternative oxidase (AOX) is a homodimeric protein whose activity can be regulated by the oxidation/reduction state and by α-keto acids. To further clarify the role of AOX in the skunk cabbage, Symplocarpus renifolius, we have performed expression and functional analyses of the encoding gene. Among the various tissues in the skunk cabbage, SrAOX transcripts were found to be specifically expressed in the thermogenic Spadix. Moreover, our data demonstrate that the SrAOX protein exists as a non-covalently associated dimer in the thermogenic Spadix, and is more sensitive to pyruvate than to other carboxylic acids. Our results suggest that the pyruvate-mediated modification of SrAOX activity plays a significant role in thermoregulation in the skunk cabbage.

  • Modeling of the thermoregulation system in the skunk cabbage: Symplocarpus foetidus.
    Physical review. E Statistical nonlinear and soft matter physics, 2007
    Co-Authors: Ken Takahashi, Yoshihiko Onda, Kikukatsu Ito, Takanori Ito, Shigeki Chiba, T. Endo, Hiroshi Osada
    Abstract:

    This paper presents a model of the thermoregulation system of the Spadix of skunk cabbage Symplocarpus foetidus which regulates its internal temperature at around 20 degrees C during flowering even when the ambient air temperature drops below freezing. From the temperature responses of the Spadix to changing ambient air temperature, we assumed that the thermoregulation system of the Spadix is probably one of negative feedback control. The feedback signals are based on the rate of temperature change of the Spadix over time. A signal is factored into the biochemical energy generator, and becomes biochemical energy, some of which becomes heat. Comparing our proposed model temperature responses and those of the living Spadix, we found good agreement. In the process of engineering the model, the existence of two regulatory pathways in the thermoregulation system was simulated, and our proposed model appears to provide the necessary elements to explain the fundamental mechanism of the thermoregulation system of S. foetidus.

  • Temperature-Triggered Periodical Thermogenic Oscillations in Skunk Cabbage (Symplocarpus foetidus)
    Plant & cell physiology, 2004
    Co-Authors: Kikukatsu Ito, Yoshihiko Onda, Takanori Ito, Matsuo Uemura
    Abstract:

    The natural occurrence of temperature-triggered and light-independent thermogenic oscillation in the Spadix of skunk cabbage, Symplocarpus foetidus, was discovered. The identified thermogenic oscillator had an accurate periodical cycle (ca. 60 min per cycle) that apparently responded to an increase or decrease in the Spadix temperature with a threshold of less than 0.9 degrees C. Neither a constant ambient air temperature nor transient changes in the ambient air temperature within 10 min (19 degrees C --> 15 degrees C --> 19 degrees C) induced the temperature oscillation in the Spadix. Moreover, the periodical cycles were independent of the weight of the Spadix (2.5-9.2 g) and the amplitudes of the temperature oscillations were correlated with the magnitude of the changes in the Spadix temperatures. These results imply that periodical temperature oscillations in the Spadix of S. foetidus possess a quantitative regulatory process that involves a temperature sensation and subsequent heat production. Based on these results, we propose a time-dependent thermogenic oscillatory model that acts as a precise thermal regulator under dynamic environmental temperature changes.

  • structural requirements for the perception of ambient temperature signals in homeothermic heat production of skunk cabbage symlocarpus foetidus
    Plant Cell and Environment, 2003
    Co-Authors: Kikukatsu Ito, Yoshihiko Onda, T Sato, Y Abe, Matsuo Uemura
    Abstract:

    The Spadix of skunk cabbage, Symplocarpus foetidus, is capable of maintaining an internal temperature of around 20 degrees C even when the ambient temperature drops to around 0 degrees C. To determine the crucial structure that is required for detection of ambient temperature signals, detailed measurements of the temperatures of the Spadix were made under field conditions. The Spadix temperature was well regulated even when the spathe or the leaf of the plant was removed. Furthermore, maintenance of the temperature of the central stalk at either 10 or 20 degrees C had no effect on the thermoregulation when the ambient temperature increased from 10 to 25 degrees C or decreased from 20 to 8 degrees C. Therefore, it seemed that the heat production in the Spadix required neither the spathe, the leaf, nor the central stalk for perception of the external temperature signals. Finally, analysis of sugar composition in xylem exudates showed that the concentrations of sucrose, glucose, and fructose, all of which are potential energy sources of thermogenesis, did not change significantly at different ambient temperatures. It is concluded that the Spadix is a unique organ in which the perception of ambient temperature signals and heat production occurs in S. foetidus.

Hiroshi Osada - One of the best experts on this subject based on the ideXlab platform.

  • Modeling of thermoregulation in the skunk cabbage in relation to meteorological factors.
    Agricultural and Forest Meteorology, 2009
    Co-Authors: Ken Takahashi, Kikukatsu Ito, Takanori Ito, Shigeki Chiba, Hiroshi Osada
    Abstract:

    A model is proposed to calculate the Spadix temperature of the skunk cabbage Symplocarpus foetidus which regulates its internal temperature at around 20 °C during the female stage even when the ambient air temperature drops below freezing. The model is based on energy balance of the Spadix under field conditions. The input data are standard meteorological data and Spadix parameters. The model output was compared with experimental data collected under different climate conditions. The agreement between observed and calculated Spadix temperatures was fairly good.

  • Algorithm for Temperature Control in the Skunk Cabbage, Symplocarpus Foetidus
    Biotechnology & Biotechnological Equipment, 2008
    Co-Authors: K. Takahashi, Kikukatsu Ito, T. Ito, T. Endo, S. Chiba, Hiroshi Osada
    Abstract:

    ABSTRACTThis paper presents a temperature control algorithm for the Spadix of the skunk cabbage Symplocarpus foetidus, a plant which holds its Spadix temperature nearly constant. We derive the control algorithm from a proposed thermoregulation model of the Spadix of S. foetidus. In addition, we investigate the control algorithm of S. foetidus for general industrial applications from a control engineering perspective by running simulations and applying it to actual equipment. The temperature control algorithm responds to the rate of change of the controlled variable over time and adjusts the output of the controller as required to minimize the rate of change. The control algorithm of the Spadix of S. foetidus is robust to perturbations in the controlled object, and the control algorithm incorporated into a microprocessor successfully controls the performance of actual equipment.

  • Modeling of the thermoregulation system in the skunk cabbage: Symplocarpus foetidus.
    Physical review. E Statistical nonlinear and soft matter physics, 2007
    Co-Authors: Ken Takahashi, Yoshihiko Onda, Kikukatsu Ito, Takanori Ito, Shigeki Chiba, T. Endo, Hiroshi Osada
    Abstract:

    This paper presents a model of the thermoregulation system of the Spadix of skunk cabbage Symplocarpus foetidus which regulates its internal temperature at around 20 degrees C during flowering even when the ambient air temperature drops below freezing. From the temperature responses of the Spadix to changing ambient air temperature, we assumed that the thermoregulation system of the Spadix is probably one of negative feedback control. The feedback signals are based on the rate of temperature change of the Spadix over time. A signal is factored into the biochemical energy generator, and becomes biochemical energy, some of which becomes heat. Comparing our proposed model temperature responses and those of the living Spadix, we found good agreement. In the process of engineering the model, the existence of two regulatory pathways in the thermoregulation system was simulated, and our proposed model appears to provide the necessary elements to explain the fundamental mechanism of the thermoregulation system of S. foetidus.

Takanori Ito - One of the best experts on this subject based on the ideXlab platform.

  • Modeling of thermoregulation in the skunk cabbage in relation to meteorological factors.
    Agricultural and Forest Meteorology, 2009
    Co-Authors: Ken Takahashi, Kikukatsu Ito, Takanori Ito, Shigeki Chiba, Hiroshi Osada
    Abstract:

    A model is proposed to calculate the Spadix temperature of the skunk cabbage Symplocarpus foetidus which regulates its internal temperature at around 20 °C during the female stage even when the ambient air temperature drops below freezing. The model is based on energy balance of the Spadix under field conditions. The input data are standard meteorological data and Spadix parameters. The model output was compared with experimental data collected under different climate conditions. The agreement between observed and calculated Spadix temperatures was fairly good.

  • Pyruvate-sensitive AOX exists as a non-covalently associated dimer in the homeothermic Spadix of the skunk cabbage, Symplocarpus renifolius
    FEBS letters, 2007
    Co-Authors: Yoshihiko Onda, Yasuko Ito-inaba, Megumi Ichikawa, Yoshiaki Kato, Kazushige Matsukawa, Yukie Abe, Takanori Ito, Miyuki Morohashi, Yuka Ito, Minoru Otsuka
    Abstract:

    The cyanide-resistant alternative oxidase (AOX) is a homodimeric protein whose activity can be regulated by the oxidation/reduction state and by α-keto acids. To further clarify the role of AOX in the skunk cabbage, Symplocarpus renifolius, we have performed expression and functional analyses of the encoding gene. Among the various tissues in the skunk cabbage, SrAOX transcripts were found to be specifically expressed in the thermogenic Spadix. Moreover, our data demonstrate that the SrAOX protein exists as a non-covalently associated dimer in the thermogenic Spadix, and is more sensitive to pyruvate than to other carboxylic acids. Our results suggest that the pyruvate-mediated modification of SrAOX activity plays a significant role in thermoregulation in the skunk cabbage.

  • Modeling of the thermoregulation system in the skunk cabbage: Symplocarpus foetidus.
    Physical review. E Statistical nonlinear and soft matter physics, 2007
    Co-Authors: Ken Takahashi, Yoshihiko Onda, Kikukatsu Ito, Takanori Ito, Shigeki Chiba, T. Endo, Hiroshi Osada
    Abstract:

    This paper presents a model of the thermoregulation system of the Spadix of skunk cabbage Symplocarpus foetidus which regulates its internal temperature at around 20 degrees C during flowering even when the ambient air temperature drops below freezing. From the temperature responses of the Spadix to changing ambient air temperature, we assumed that the thermoregulation system of the Spadix is probably one of negative feedback control. The feedback signals are based on the rate of temperature change of the Spadix over time. A signal is factored into the biochemical energy generator, and becomes biochemical energy, some of which becomes heat. Comparing our proposed model temperature responses and those of the living Spadix, we found good agreement. In the process of engineering the model, the existence of two regulatory pathways in the thermoregulation system was simulated, and our proposed model appears to provide the necessary elements to explain the fundamental mechanism of the thermoregulation system of S. foetidus.

  • Temperature-Triggered Periodical Thermogenic Oscillations in Skunk Cabbage (Symplocarpus foetidus)
    Plant & cell physiology, 2004
    Co-Authors: Kikukatsu Ito, Yoshihiko Onda, Takanori Ito, Matsuo Uemura
    Abstract:

    The natural occurrence of temperature-triggered and light-independent thermogenic oscillation in the Spadix of skunk cabbage, Symplocarpus foetidus, was discovered. The identified thermogenic oscillator had an accurate periodical cycle (ca. 60 min per cycle) that apparently responded to an increase or decrease in the Spadix temperature with a threshold of less than 0.9 degrees C. Neither a constant ambient air temperature nor transient changes in the ambient air temperature within 10 min (19 degrees C --> 15 degrees C --> 19 degrees C) induced the temperature oscillation in the Spadix. Moreover, the periodical cycles were independent of the weight of the Spadix (2.5-9.2 g) and the amplitudes of the temperature oscillations were correlated with the magnitude of the changes in the Spadix temperatures. These results imply that periodical temperature oscillations in the Spadix of S. foetidus possess a quantitative regulatory process that involves a temperature sensation and subsequent heat production. Based on these results, we propose a time-dependent thermogenic oscillatory model that acts as a precise thermal regulator under dynamic environmental temperature changes.

Hugh D. Wilson - One of the best experts on this subject based on the ideXlab platform.