巻号一覧
75 巻 (2019)
- 4 号 p. 173-
- 3 号 p. 129-
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75 巻, 3 号
選択された号の論文の6件中1～6を表示しています
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Ryo MATSUDA, Akihiro UENO, Kazuhiro FUJIWARA2019 年 75 巻 3 号 p. 129-136
発行日: 2019年
公開日: 2019/07/10
[早期公開] 公開日: 2019/06/21ジャーナル フリーWe investigated the effects of photosynthetic photon flux density (PPFD), air temperature, and CO2 concentration before gene transfer on the accumulation level of hemagglutinin (HA), an influenza vaccine antigen, in Nicotiana benthamiana leaves in a transient gene expression system. Plants were treated for two weeks before gene transfer with different levels of PPFD, air temperature or CO2 concentration in separate experiments. Leaf fresh mass (FM), leaf HA content per unit FM, and leaf HA content per plant at 6 d post infiltration (6 DPI) for gene transfer all tended to increase with increasing average PPFD during the treatment period. Leaf FM and leaf HA content per plant at 6 DPI were significantly greater at an average day air temperature of 25°C-30°C during the treatment period than at 20°C-25°C. No clear effects of CO2 concentration were found on either growth or leaf HA content under the conditions tested in the present study. There was a positive correlation between leaf HA content per unit FM at 6 DPI and leaf FM at 0 or 6 DPI in plants grown under different PPFDs and air temperatures. Preparing plants with increased leaf FM by applying high PPFD and/or high air temperature before gene transfer should increase not only total HA yield per plant but also HA content per unit leaf biomass at harvest.抄録全体を表示PDF形式でダウンロード (719K) -
Fabio ORLANDI, Aldo RANFA, Luigia RUGA, Marco FORNACIARI2019 年 75 巻 3 号 p. 137-143
発行日: 2019年
公開日: 2019/07/10
ジャーナル フリーHazelnut trees, were investigated in central Italy to study their biology and relationships with principal environmental variables. The cyclical repetition of seasonal development in plants may be sensitive to meteorological variation, making phenology of particular interest for studying the climate change effects on vegetative development using new standardization techniques for observing and interpreting the growth of different plant species. Plants of Corylus avellana L. planted in phenological gardens in central Italy areas were examined to analyse the phenology of their growth stages in relation to different climate characteristics. Phenological observations following the guidelines of the International Phenological Gardens network were carried out during a 13-year period. Temperature and solar radiation showed the highest homogeneity among the different vegetative phases in both of the study areas, while other meteorological variables (Precipitation and RH) were heterogeneous also considering the particular water table levels present in one of the two observation areas. Two periods (“first leaf development” (FLD) and “leaf presence period” (LPP)) were considered to study the influence of meteorological variables on plant development during important vegetative periods. A certain shortening of the first period was attributed to the delay in bud swelling beginning during the study period. In contrast, a lengthening of the LPP, was related to the progressive delay in the senescence phase.抄録全体を表示PDF形式でダウンロード (293K) -
Yuji MASUTOMI, Yousuke SATO, Atsushi HIGUCHI, Akinori TAKAMI, Teruyuki ...2019 年 75 巻 3 号 p. 144-152
発行日: 2019年
公開日: 2019/07/10
ジャーナル フリーIn urban areas around the world, air temperature increases due to global warming and urbanization are adversely affecting human health and living environments. We used a numerical weather forecasting model to quantitatively simulate the effectiveness of citizen-driven urban forestry, the voluntary activity of citizens to plant and maintain trees in their residential areas, as a method for reducing summer air temperatures in the Tokyo metropolitan area, the largest urban area in Japan. We calculated the daily maximum air temperature for 10 days in the summer of 2007, and simulated the effects of five different levels of increased urban forest area per capita according to population distribution using albedo, heat capacity, and evapotranspiration. Increasing the forest cover by 3.3 m2 per capita reduced the daily maximum air temperature by only 0.014 °C, although the effect increased linearly with higher forest cover per capita. If forest planting is increased to about 30 m2 per capita, the air temperature reduction in the center of Tokyo could reach 0.4 to 0.5 °C, comparable to the increase in urban air temperature over the past hundred years due to global warming. The results suggest that the collective actions of individual citizens to increase urban forest cover can produce a significant effect on the mitigation of high air temperatures due to the urban heat island effect and climate change.抄録全体を表示PDF形式でダウンロード (2804K) -
Reiji KIMURA, Masao MORIYAMA2019 年 75 巻 3 号 p. 153-159
発行日: 2019年
公開日: 2019/07/10
ジャーナル フリーThe Aridity Index (AI; the ratio of precipitation to potential evaporation), is an indirect, essentially climatic index that has been used to identify global distributions of arid regions. Since the turn of the century, the increasingly widespread availability of satellite data has led many researchers to use it to assess desertification. In this study we used a satellite-based aridity index (SbAI) to investigate global changes of land surface aridity from 2000 to 2017. Degraded land areas were identified by using SbAI and the normalized difference vegetation index (NDVI). Here, degraded land include existing desert and the land having both permanent and temporal dust erodibility. Our results showed that actual land condition by SbAI became dryness than that derived from the climatic AI indicator in arid, semi-arid, and dry sub-humid regions and that the dryness was reflected in an increase in the extent of areas classified as hyper-arid. From 2000 to 2017, however, the annual extent of the wetter areas within arid regions (semi-arid and dry sub-humid regions) increased, and that of drier areas (hyper-arid and arid regions) decreased. The global area of degraded land decreased slightly between 2000 and 2017, and the annual average area for that period was 13.5×106 km2 (9.2% of total land area).抄録全体を表示PDF形式でダウンロード (2459K) -
Tomoki SHIBUYA, Takuma TAKAHASHI, Shun HASHIMOTO, Manabu NISHIYAMA, Yo ...2019 年 75 巻 3 号 p. 160-165
発行日: 2019年
公開日: 2019/07/10
ジャーナル フリーThe effects of overnight radiation with monochromatic light on flower budding using far-red- and blue light-emitting diodes (FR and B, respectively) were investigated in Eustoma grandiflorum under controlled temperature and 8-h sunlight. Flower budding was promoted by FR and B, while it was not observed under short-day conditions with an 8-h photoperiod during the treatment period. The flower budding with FR was earlier than with B. Expression analysis of flowering-related genes and potential light quality-responsive genes was performed to find genes involved in light quality-dependent regulation of flowering. The levels of EgFTL and EgSOC1L mRNA increased preceding flower budding with FR and B, suggesting that both genes could be involved in the effects on flowering brought about by far-red and blue lights. Later and lower expression of these genes induced by B compared to FR could be associated with the weak promotion of flowering by blue light in E. grandiflorum. In potential light quality-responsive genes, the level of EgBTB-POZ1 mRNA peaked with EgFTL with FR. Collectively, EgFTL and EgSOC1 likely promote flowering with FR and B, and EgBTB-POZ1 might be possibly involved in the promotion of flowering with FR.抄録全体を表示PDF形式でダウンロード (422K) -
Ryo MATSUDA, Kota HAYANO, Satoshi YAGI, Kazuhiro FUJIWARA2019 年 75 巻 3 号 p. 166-172
発行日: 2019年
公開日: 2019/07/10
ジャーナル フリーThe feasibility of estimating the number of air exchanges per hour (N) of a naturally ventilated greenhouse in real time using neural network (NN) models was evaluated. An aerodynamic (AD) model and an empirical model were also used to compare different types of model. The value of N for an eight-span Venlo-type greenhouse with roof vents containing no plants was measured using the tracer gas method with CO2 for 17 d. An AD model derived from Bernoulli’s principle, an empirical model, and several NN models in which explanatory variables differed were trained and validated with 4,508 data points subjected to 10-fold cross-validation. We first compared the AD model, the empirical model, and two NN models that used the same explanatory variables in the empirical model, with and without wind direction. The mean accuracy (in terms of root mean square error (RMSE) and coefficient of determination (r2) in the relationship between measured and estimated N values) was the highest for the two NN models, followed by the empirical model and AD model. We next compared four NN models. The differences among them included that, as explanatory variable(s), only the difference between inside (Ti) and outside (To) air temperatures or both Ti and To was used and whether solar irradiance (I) was used or not. There was a slight improvement in accuracy when using I, irrespective of how air temperature was handled. The NN models thus tended to exhibit a higher degree of accuracy in estimating N of a naturally ventilated greenhouse than the AD and empirical models considered in this study. For the NN model that performed the best in our comparison, a mean RMSE of 1.08 h−1 and a mean r2 of 0.79 were observed.抄録全体を表示PDF形式でダウンロード (664K)
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