Nitrogen Isotope Study on Nitrate-Contaminated Groundwater in the Sichuan Basin, China

We investigated the expansion of NO₃ ^?-contaminated groundwater in the Sichuan Basin, China. Nitrogen concentrations and isotopic ratios of NH₄ ⁺ and NO₃ ^? were analyzed in groundwater and rain collected from four areas in this basin in order to evaluate the sources of nitrogen pollution. NH₄ ⁺ in rain, for which δ¹⁵N values are strongly negative to slightly positive ?13.4 to + 2.3‰, appears to originate from fertilizers and excretory waste. NO₃ ^? in rain (δ¹⁵N: ?10.2 to ?4.4‰) was attributed to NO _x from automobile exhaust gas. In the studied area, well water sampled from farmyards was found to have the highest δ¹⁵N_NO3 (average: +9.7 ± 4.7‰), indicating contamination by domestic sewage as animal excrement. The lowest δ¹⁵N_NO3 (?0.2 ± 3.7‰), found in spring water, indicates that the studied groundwater samples are widely affected by air contaminants (mainly as nitrogen oxides) resulted from fuel combustions. The δ¹⁵N_NO3 (+3.7 ± 2.1‰) values of well water from farmland are between these levels, suggesting that NO₃ ^? contamination results primarily from cultivation using nitrogen fertilizers, although the contribution from animal excrement cannot be excluded. These results demonstrate that the studied groundwater is widely polluted by locally derived nitrogen sources.     

Fusarium root rot of prairie gentian caused by a species belonging to the <Emphasis Type="Italic">Fusarium solani</Emphasis> species complex

Rotting of roots and stem bases and wilting of entire plants were found on a gentianaceous flowering plant, prairie gentian (Eustoma grandiflorum), grown in Kagawa Prefecture in the southwest region of Japan in April 2001. A mitosporic fungus, isolated repeatedly from the diseased plants, was identified as a species belonging to the clade 3 of Fusarium solani species complex based on the morphology and the sequence of the translation elongation factor gene. It was demonstrated to cause the disease by inoculating potted plants and reisolating the fungus from the diseased plants. We propose the name “Fusarium root rot of prairie gentian” for this disease.     

Amino acid substitution at position 95 in rabies virus matrix protein affects viral pathogenicity

We previously reported that rabies virus strain CE(NiM), but not the parental Ni-CE strain, killed mice after intracerebral inoculation. CE(NiM) and Ni-CE are genetically identical except for two amino acids at positions 29 and 95 in the M protein. In this study, to identify which residue determines the pathogenicity, we examined pathogenicities of two Ni-CE mutants, CE(NiM29) and CE(NiM95), which were established by replacement of an amino acid residue at position 29 or 95 in the Ni-CE M protein with the corresponding residue of CE(NiM), respectively. We found that CE(NiM95), but not CE(NiM29), killed mice, indicating that the amino acid at position 95 in the M protein is the pathogenic determinant.     

The effect of small interfering RNA (siRNA) against the Bcl-2 gene on apoptosis and chemosensitivity in a canine mammary gland tumor cell line

The aim of this study was to investigate whether downregulation of Bcl-2 expression by small interfering RNA (siRNA) against the canine Bcl-2 gene would enhance the apoptosis and sensitivity of a canine mammary gland tumor cell line (CF33) to doxorubicin. Transfections of CF33 with siRNA were performed using cationic liposomes. Sequence-specific downregulation of Bcl-2 expression was measured by semiquantitative RT-PCR and Western blot analysis. Total viable cells were determined by MTS assay and apoptotic cell rates were determined by the immunohistochemical analysis on ssDNA. Our data showed the siRNA downregulated Bcl-2 expression which increased apotosis and also increased the sensitivity of CF33 to doxorubicin. This study indicated that downregulation of Bcl-2 expression by siRNA would be useful as a new protocol to increase the effect of doxorubicin on treatment of canine mammary gland tumors, requiring a detailed evaluation of siRNA in vivo.     

Early dead ripe of bread wheat and durum wheat caused by Ophiosphaerella korrae and evaluation of the fungal influence on barley,rice, and soybean

Journal of General Plant Pathology - A ripening disorder with early blighting of foliage including spike bleaching was observed on bread wheat in May 2017 and durum wheat in May 2018 in...     

Manure application has an effect on the carbon budget of a managed grassland in southern Hokkaido,Japan

Abstract

The carbon (C) budget of managed grassland in a cool-temperate region of Japan was estimated using a combination of eddy covariance and the biometric method for five years, to evaluate the effect of manure application. Chemical fertilizer was applied to the fertilizer (F) plot at a rate of 79 ± 20 kg N ha^?1 yr^?1. In the manure (M) plot, dairy cattle manure was applied at a rate of 10 Mg fresh matter ha^?1 yr^?1 (1923 ± 407 kg C ha^?1 yr^?1, 159 ± 68 kg N ha^?1 yr^?1). There was no significant difference in seasonal gross primary production (GPP) and harvest between the treatment plots, indicating that both fertilizer and manure can increase the biomass production. Annual net ecosystem production (NEP) and ecosystem respiration (RE) was significantly different between the treatment plots. The difference in RE, and between M and F plots approximates heterotrophic respiration of manure (RHm), which ranged from 0.9 to 1.3 Mg C ha^?1 yr^?1. Average annual RHm was 1.1 ± 0.4 Mg C ha^?1 yr^?1, and accounted for 56% of the total amount of applied manure C. The annual net biome production (NBP) in the M plot (from 0.0 to 1.5 Mg C ha^?1 yr^?1) was significantly higher than in the F plot (?1.4 to 0.5 Mg C ha^?1 yr^?1). The long-term effect of manure application combined with chemical fertilizer did not reduce grass production compared with chemical fertilizer only; however, manure application decreased the NEP throughout manure decomposition, and long-term manure application enhanced the NBP.     

Yield and dry matter dynamics of vegetative and reproductive organs in Japanese and US soybean cultivars

ABSTRACT

Recently, US soybean cultivars have exhibited higher yields than Japanese soybean cultivars. To identify the determinants for this yield difference in reference to dry matter dynamics, recently developed US cultivars and Japanese commercial cultivars were cultivated in drained paddy fields in 2012 and 2013. The total dry matter (TDM) of each cultivar was measured at the initial seed-filling stage (R5), at 30 d after R5, and at maturity (R8). From R5 to R8, the DM of abscised leaves and petioles were measured. The actual HI (with abscised leaves and petioles) and apparent HI (without abscised leaves and petioles) were determined at R8. US soybean cultivars showed higher yields and apparent TDM (without abscised leaves and petioles) than did Japanese cultivars at R8. However, the difference in actual TDM (with abscised leaves and petioles) production was not significant between US and Japanese cultivars at R8. On the other hand, the actual HI was higher in US cultivars than in Japanese cultivars. US cultivars exhibited a higher TDM distribution to the pod before R5 and a higher pod growth rate from R5 to 30 d after R5. US cultivars tended to show greater crop growth rates (CGRs) from R5 to 30 d after R5. The higher yield in US cultivars was associated with the higher actual HI, which was considered attributable to a greater TDM productivity during the seed-filling period and higher DM distribution in the pod before R5.     

Development and evaluation of a support system for forest education

Field education programs have been conducted throughout the world because learning through experience is an important process in environmental and forest education. We developed a support system for forest education that consists mainly of a Global Positioning System (GPS) and personal digital assistant (PDA). Moreover, field experiments were conducted to evaluate educational efficacy as well as usability of the developed system. Through a post-questionnaire the developed system was highly evaluated in terms of educational efficacy and enjoyment. On the other hand, the questionnaire revealed the need for technical improvements. For example, the drawing function, which involves the use of a stylus pen, was the most poorly evaluated because a drawing could not be partially erased as with an eraser and representation was not sufficiently accurate. In addition, positions where information on nature appeared were sometimes inaccurate due to positional errors caused by using the autonomous GPS. Some participants answered that walking with the developed system was also troublesome due to its shape and size. In fact, they did not feel comfortable about the cables connecting the GPS to the PDA and GPS to its antenna. Although there were some problems with the system, we believe that the field education program was successful because 95% of the participants answered that they would join a similar program again.     

Proliferating effect of extracts from woods and fungi on rat vibrissa dermal papilla cells

Hair growth is a highly regulated cyclical process. Three distinct phases have been defined for the mammalian cycle: anagen (growing phase), catagen (regression phase), and telogen (resting phase). Although little is known about the mechanism that regulates the hair cycle, it is believed that dermal papillae (DP) derived from mesenchymal cells play an essential role in controlling the established hair follicle and hair cycle. The purpose of this investigation was to find the components of woods and fungi that exert a proliferative activity on DP cells. Results show that the fungus YL161 (ethyl acetate extract, 1ppm),Agaricus blazei (ethyl acetate extract, 0.1 ppm), and the bark ofCamptotheca cuminata (methanol extract of bark, 0.1 ppm) exhibit higher growth-promoting activity than pentadecanoic acid. These components that have a proliferative effect on DP cells may be useful hair growth-stimulating materials and can be used to understand the mechanism of hair growth.     

Virtual forest: design and evaluation of a walk-through system for forest education

Forest education is generally conducted in a real forest to provide learners a direct experience with reality. However, often it is not easy to participate in forest education programs carried out in remote places due to distance, limited time, or economic or physical restrictions. Therefore, we developed a walk-through system for forest education in a virtual forest and evaluated its educational efficacy as well as usability through indoor experiments. The virtual forest was constructed with omnidirectional images taken in a forest using a digital camera with an omnidirectional vision sensor. The results of the postquestionnaire showed that the developed system was highly evaluated by the participants in the experiments in terms of educational efficacy and enjoyment. Also, comparison of results of prequestionnaire and postquestionnaire showed that it had educational value. On the other hand, some technical problems in the developed system were revealed. For example, 45.0% of the participants answered that the walk-through in the virtual forest did not proceed with sufficient smoothness, and encountered unexpected slowdowns and stops. In addition, image quality was not high enough to identify small objects in the virtual forest. Regardless of these problems, we believe that the computer-based forest education was successful because 88.3% of the participants answered that they would like to join a similar program again and 90.0% answered that they would like to visit the real forest that the virtual forest imitated.