Photosynthetic and Growth Responses in a Pioneer Tree (Japanese White Birch) and Competitive Perennial Weeds (Eupatorium sp.) Grown Under Different Regimes With Limited Water Supply to Waterlogging.

For a successful natural regeneration of Japanese white birch (Betula platyphylla var. japonica), competitive vegetation should be managed. Here, we clarified how soil water condition modifies the competitiveness of Japanese white birch against perennial weeds, Eupatorium species, based on an ecophysiological approach combining a glasshouse experiment and a field survey. We investigated photosynthetic and growth responses to various water regimes from water deficit to waterlogging (two times-a-week irrigation, three times-a-week irrigation, half waterlogging, and full waterlogging) in pot-grown seedlings of Japanese white birch and the competitive weed Eupatorium makinoi. The ratio of seedling height of Japanese white birch to seedling height of E. makinoi showed a decreasing trend from two times-a-week irrigation to full waterlogging, which suggests a lower competitiveness for light resource in Japanese white birch with increasing soil wetness. The maximum rate of Rubisco carboxylation (Vc,max) based on unit N was lower in waterlogging treatments than in two times- and three times-a-week irrigation in Japanese white birch, whereas E. makinoi showed the opposite response. This suggests that N partitioning into Rubisco and/or Rubisco activation might be suppressed in Japanese white birch but enhanced in E. makinoi under waterlogging. The maximum photochemical efficiency of photosystem II (Fv/Fm) was also lower in seedlings of Japanese white birch grown under waterlogging treatments. We further conducted a field survey on the relationship between Fv/Fm and topographic wetness index (TWI) in seedlings of Japanese white birch and E. glehnii (closely related to E. makinoi) naturally grown in a study site 5 years after canopy tree cutting. Lower Fv/Fm was observed in seedlings of Japanese white birch with increasing TWI, whereas no significant trend was observed in E. glehnii, in agreement with the glasshouse experiment. Thus, keeping soils not always humid might be favorable to photosynthetic performance and growth competitive ability of Japanese white birch against Eupatorium species.

Springtime photoinhibition constrains regeneration of forest floor seedlings of Abies sachalinensis after a removal of canopy trees during winter.

A clear-cutting of canopy trees during winter often causes severe foliar damage during the following spring in forest floor seedlings of Abies sachalinensis, a typical shade-tolerant evergreen coniferous species. The maximum photochemical efficiency of photosystem II after an overnight dark adaptation showed a temporary decrease immediately before budbreak in 1-year-old shoots of A. sachalinensis seedlings grown under full sunlight in a nursery, suggesting "springtime photoinhibition" related to the phenology of evergreen coniferous species. In the field, a greater rate of canopy tree cutting during winter was associated with more severe photoinhibition in the following spring, immediately before budbreak, which subsequently resulted in a reduction in carbon gain in 1-year-old shoots, and consequently suppressed the growth of current-year shoots. Although photoinhibition under low temperature is a well-known factor to determine the survival rate of tree seedlings during winter in cool regions, the present study additionally proposes that the temporary increase in the susceptibility to photoinhibition in springtime i.e. "springtime photoinhibition" would be a constraint for the regeneration of coniferous seedlings especially when the canopy trees are removed during winter.

Gastric schwannoma exhibiting increased fluorodeoxyglucose uptake.

This is the first case of gastric schwannoma that exhibited increased accumulation of [(18)F] fluorodeoxyglucose (FDG) on positron emission tomography (PET) imaging. The patient was a 60-year-old woman in whom esophagogastroduodenoscopy showed a submucosal tumor, about 25 mm in size, in the upper body of the stomach, with ulceration at the top of the tumor. Endoscopic ultrasonography revealed a well-defined hypoechoic mass located in the proper muscle layer of the stomach. The specimen taken from the tumor showed only inflammatory degenerative tissue. Abdominal computed tomography revealed a tumor in the upper body of the stomach. FDG-PET showed FDG uptake (standardized uptake value [SUV] max 5.8) coincident with the tumor. Hence, the tumor was diagnosed initially as a gastrointestinal stromal tumor of the stomach. Laparoscopic partial gastrectomy was performed. Pathological examination showed that the tumor consisted of spindle cells with large nuclei, and mitosis was absent. The Ki-67 labeling index of the tumor cells was 4%. Immunohistochemically, the tumor cells showed a positive reaction for S-100 protein, whereas they were negative for KIT, CD 34, and alpha-smooth muscle actin protein. The tumor was diagnosed as a benign gastric schwannoma. Gastric schwannoma should be included in the differential diagnosis of submucosal tumors of the stomach with FDG uptake.

Detecting deforestation with a spectral change detection approach using multitemporal Landsat data: a case study of Kinabalu Park, Sabah, Malaysia.

Tropical deforestation is occurring at an alarming rate, threatening the ecological integrity of protected areas. This makes it vital to regularly assess protected areas to confirm the efficacy of measures that protect that area from clearing. Satellite remote sensing offers a systematic and objective means for detecting and monitoring deforestation. This paper examines a spectral change approach to detect deforestation using pattern decomposition (PD) coefficients from multitemporal Landsat data. Our results show that the PD coefficients for soil and vegetation can be used to detect deforestation using change vector analysis (CVA). CVA analysis demonstrates that deforestation in the Kinabalu area, Sabah, Malaysia has significantly slowed from 1.2% in period 1 (1973 and 1991) to 0.1% in period 2 (1991 and 1996). A comparison of deforestation both inside and outside Kinabalu Park has highlighted the effectiveness of the park in protecting the tropical forest against clearing. However, the park is still facing pressure from the area immediately surrounding the park (the 1 km buffer zone) where the deforestation rate has remained unchanged.

Local gastric and serum concentrations of rebamipide following oral ingestion in healthy volunteers.

The purpose of this study was to investigate whether sufficient concentrations of rebamipide (COR) are actually present in the stomach after its oral ingestion at an ordinary clinical dose. Twenty healthy volunteers (total 42 man-days) participated in the study. After ingestion of 100, 200, or 300 mg of rebamipide, endoscopy was performed at 1, 2, 4, and 6 hr, and gastric mucosa or gastric mucus was taken from the antrum. Venous blood samples were taken simultaneously. Samples were analyzed by high-performance liquid chromatography. The COR in the gastric mucosa and gastric mucus did not depend on the original amount ingested. After ingestion of rebamipide, each COR was higher than 10(-4) M (37 microg/g tissue) at 1 or 2 hr. On the other hand, the COR in serum did depend on the amount ingested and was lower than 10(-6) M (0.37 microg/ml) at every time tested. These results suggest that the COR in the stomach exceeds the levels that are needed for various antiulcer actions and that the rebamipide levels present in the gastric mucosa and gastric mucus result from local penetration.