Morphological and photosynthetic studies on Gracilarian species from Trat Province, eastern Thailand

Morphological and photosynthetic characteristics of the three Thai species of Gracilaria, G. changii, G. firma and G. salicornia distributed in the same habitat at Cho Bay, Trat Province, eastern Thailand were studied. The three species can be identified morphologically, however, some specimens have intermediate morphologies among them. G. firma has terminal branches without or with some furcations and blunt apices, first-order of branches always constricted at the bases; G. changii has many branches, inflated at the middle and tapering toward apices, all branches abruptly constricted at the bases; G. salicornia has cylindrical to compressed branches with regular or irregular arrangement of branches, constricted or continuous and intermediate species has branches inflated, tapering to apices, with and without constriction at bases. To elucidate the species status of Gracilaria species, we examined their photosynthetic and respiratory responses to irradiance and temperature by Oxygen Analyzer Series 3600. Net photosynthetic rate in species of Gracilaria from Trat Province was dependent on temperature. It increased with an increase in temperature from 25-35℃, while the rate decreased at 40℃. Photosynthetic responses were similar for all species when plants were exposed from 30 to 35℃. The P_ was significantly highest at 35℃ (0.39mg O_2cm^h^) for intermediate species, while the lowest was at 40℃ in G. firma (0.09mg O_2cm^h^). The photosynthetic rate responses to high irradiance and temperature by intermediate species are indicative of either adaptation to environmental variation or an outcome of hybridization between the three species

地震発生帯における深部掘削孔を用いた長期計測

Large earthquakes occur frequently in subduction zones. Most earthquakes are generated in the seismogenic zone, a fairly limited area confined to the shallower regions of the subduction plate boundary. To understand the processes of earthquake generation, it is essential to monitor the physical and mechanical properties of the seismogenic zone over long periods. At present, there are no deep borehole observations of the seismogenic zone more than 3km below seafloor, because it has, until now, been impossible to penetrate to such depths below the sea floor. The Integrated Ocean Drilling Program (IODP), scheduled to begin in 2003, plans to drill boreholes beneath the ocean floor using a multiple-drilling platform operation. The IODP riser-quipped drilling ship (Chikyu) enables the emplacement of boreholes up to 0km beneath the ocean floor, and will provide opportunities to conduct long-term deep borehole observations in the seismogenic zone. Long-term borehole observations in the seismogenic zone are expected to require the development of advanced sampling, monitoring, and recording technology. Here, we discuss the scientific objectives, engineering and technical challenges, and experimental design for a deep borehole, long-term deepborehole monitoring system aimed at understanding the processes of earthquake generation in the seismogenic zone of subduction plate boundaries. We focus specifically on the relationships between environmental conditions in the deep subsurface, details of monitoring and recording, and design and implementation of scientific tools and programs

Morphological and photosynthetic studies on Gracilarian species from Trat Province, eastern Thailand

Morphological and photosynthetic characteristics of the three Thai species of Gracilaria, G. changii, G. firma and G. salicornia distributed in the same habitat at Cho Bay, Trat Province, eastern Thailand were studied. The three species can be identified morphologically, however, some specimens have intermediate morphologies among them. G. firma has terminal branches without or with some furcations and blunt apices, first-order of branches always constricted at the bases; G. changii has many branches, inflated at the middle and tapering toward apices, all branches abruptly constricted at the bases; G. salicornia has cylindrical to compressed branches with regular or irregular arrangement of branches, constricted or continuous and intermediate species has branches inflated, tapering to apices, with and without constriction at bases. To elucidate the species status of Gracilaria species, we examined their photosynthetic and respiratory responses to irradiance and temperature by Oxygen Analyzer Series 3600. Net photosynthetic rate in species of Gracilaria from Trat Province was dependent on temperature. It increased with an increase in temperature from 25-35℃, while the rate decreased at 40℃. Photosynthetic responses were similar for all species when plants were exposed from 30 to 35℃. The P_<max> was significantly highest at 35℃ (0.39mg O_2cm^<-2>h^<-1>) for intermediate species, while the lowest was at 40℃ in G. firma (0.09mg O_2cm^<-2>h^<-1>). The photosynthetic rate responses to high irradiance and temperature by intermediate species are indicative of either adaptation to environmental variation or an outcome of hybridization between the three species

Clinical Effect of Yakult (Cow's Milk Fermented by Some Sort of “Family Lactbacillaceae” Commonly Sold as a Soft Drink) Part II. Fluctuation of Vitamin B(1) in the Urine After Drinking Yakult

In order to determine the fluctuation of vitamin B(1) in the urine after drinking "Yakult", cow's milk fermented by some sort of "Family Lactbacillaceae", the authors made normal adults and patients with lung tuberculosis drink one bottle (60 cc) a day of Yakult successively, and estimated their content of vitamin B(1) in their urine polarographically and with paper chromatography. Results are as follows. 1. In the case of one bottle (60 cc) of Yakult successively, there occurs a little increment of vitamin B(1) content in their urine of normal adults comparing with tuberculous patients receiving chemotherapy. 2. In the case of taking one bottle of Yakult, no marked effect can be recognized in their urine of tuberculous patients receiving chemotherapy. However, when three bottles (180 cc) of Yakult are given every day, marked increase of vitamin B(1) can be observed even in their urine of the patients, and also impeding factor in polarographical estimation disappears, proving that Yakult is considerably effective in improving vitamin B(1) metabolism

Redox Potential Paradox in Na_<i>x</i>MO₂ for Sodium-Ion Battery Cathodes

Raising the operating potential of the cathode materials in sodium-ion batteries is a crucial challenge if they are to outperform state-of-the-art lithium-ion batteries. Although the layered transition metal oxides, NaMO₂ (M: transition metal), are the most promising cathode materials owing to their high theoretical capacity with much more stable nature than Li_1–<i>x</i>MO₂ system, factors influencing the redox potential have not yet been fully understood. Here, we identify redox potential paradox, <i>E</i>(Ni³⁺/Ni²⁺) > <i>E</i>(Ni⁴⁺/Ni³⁺), in an identical structural framework, namely, NaTi⁴⁺_0.5Ni²⁺_0.5O₂ and NaFe³⁺_0.5Ni³⁺_0.5O², which is induced by transition of the oxides from Mott–Hubbard to negative charge-transfer regimes. The origin of the unusually low <i>E</i>(Ni⁴⁺/Ni³⁺) is the surprisingly large contribution (over 80%) of oxygen orbital to the redox reaction, of which the primary effect on the electrochemical property is demonstrated for the first time, providing a firm platform to design better cathodes for advanced sodium-ion batteries