Program of International Symposium on Environmental and Life Science FY 2020 held at Okayama University with online presentations from abroad on January 25th, 2021

   The imbalance between the generated free radicals and the endogenous antioxidant systems causes oxidative stress implicated in the development of several chronic diseases and cancers. Epidemiological evidence has shown that the risks of certain diseases are comparatively lower in the rice-consuming regions, which might be ascribed to the presence of several bioactive phytochemicals in rice, including (poly) phenolic compounds, γ-oryzanols, tocopherols, and tocotrienols. Therefore, this paper reviews recent findings about the predominant phytochemicals in rice based on their contents, chemical structures, absorption, metabolism, and antioxidant activities. This paper also summarizes the health-promoting effects of phytochemicals in rice, thus presenting evidence for rice being developed as a rich source of antioxidants and improving our comprehension of the practicality of this staple food. Further research is warranted to explore the synergistic interaction of individual phytochemicals in rice with consideration of the underlying mechanism of the health-beneficial functions.

   Calcium ion (Ca²⁺) is a ubiquitous intracellular second messenger that regulates many cellular processes in plants as well as in animals. Guard cells respond to environmental and internal stimuli, resulting in a change in a stomatal aperture. This signaling pathway employs Ca²⁺ as a second messenger in the guard cells. Hence, elevation of cytosolic free Ca²⁺ concentration ([Ca²⁺]_cyt) can be observed in guard cells treated with phytohormones such as abscisic acid and methyl jasmonate. Several other second messengers including cyclic ADP-ribose, inositol 1,4,5-trisphosphate, and myo-inositol hexakisphosphate are involved in the [Ca²⁺]_cyt elevation in the guard cells. Moreover, several methods have been developed to observe the [Ca²⁺]_cyt elevation in the guard cells. In this mini-review, we briefly introduce the roles and regulation of the transient [Ca²⁺]_cyt elevation in the guard cells and the methods to monitor the [Ca²⁺]_cyt.

   Stomata are formed by pairs of guard cells, which control the gaseous exchange and transpirational water loss in plants. The opening and closure of stomata are regulated by the integration of numerous environmental signals and endogenous hormonal stimuli. In response to drought stress, plants synthesize a hormone, abscisic acid (ABA), which triggers the signal transduction in the guard cells and induces stomatal closure that prevents water loss by transpiration. Methyl jasmonate (MeJA) is a phytohormone that regulates various physiological processes and mediates plant defense responses. Similar to ABA, MeJA plays a role in the induction of stomatal closure. Glutathione (GSH; γ-glutamylcysteinyl glycine) is an abundant, ubiquitous, and non-enzymatic antioxidant that has significant functions in the growth, development, defense systems, signaling, and gene expression in plants. In recent years, many studies have shown that GSH is involved in the ABA- and MeJA-induced stomatal closure. In this study, we outline the involvement of GSH in the stomatal closure and discuss how GSH regulates ABA signaling and MeJA signaling in the guard cells.

   Eimeria tenella infection causes coccidiosis, which induces diarrhea and bloody stool in chicken. This infection impairs the epithelial barrier that lines the intestinal tract. The intercellular junctions are key factors for maintaining barrier integrity. However, information on the gene expression modulation of junctional molecule-related genes is still limited. This study aimed to elucidate the association between disease symptoms and the regulation of target genes. Intestinal function was evaluated using biomarker measurements. Gene expression regulation was determined by real-time quantitative polymerase chain reaction. The disruption of the intestinal barrier might be induced by lower levels of claudin-1, claudin-3, E-cadherin, occludin, and ZO-1 but higher levels of claudin-2. Our results might suggest the association between the modulation of junctional barrier molecules and major symptoms of E. tenella infection.

   Management of mangrove-aquaculture system (MAS) in the Mekong Delta needs the information of stakeholders' perceptions that are difficult to obtain. Accordingly, we applied a Soft System Methodology (SSM) to reveal the perceptions and then determine problems, key stakeholders, and suggest feasible solutions for improving the MAS. We selected Kien Vang, Ca Mau, Vietnam as a case study. Results showed the current MAS problems of management difficulty, water pollution, and low yield of aquaculture. We identified key stakeholders as local forest department (FD) and farmers. Results suggested feasible solutions to improve the current circumstance of MAS including administration, water control, yield maintenance, and urgent needs of infrastructure investment.

Program of Debrief Session of the Project Researches on “Environmental Rehabilitation in Asia” FY2020 held at Okayama University with online presentations from abroad on January 26th, 2021

   Scientists from Texas A&M AgriLife Research and the United States Department of Agriculture – Agricultural Research Service have worked together at the Blackland Research Center (BRC) in Temple, Texas for more than 80 years. Since the mid-1960's, computer models describing agricultural, environmental, and hydrological processes have been developed by scientists at BRC. Today BRC scientists continue to refine and support numerous modeling products that are used world-wide by researchers, environmental managers, and government policy makers. The Environmental Policy and Integrated Climate (EPIC) model, the Agricultural Policy and Environmental eXtender (APEX) model, and the Soil and Water Assessment Tool (SWAT) are the most prominent and heavily used. This paper briefly describes their history, general organization, usage tools, support and availability, and three example uses. In the first example, the EPIC model was used to evaluate irrigation control methods on an urban landscape. The uncalibrated results suggested that scheduled irrigation was more efficient than sensor-based. This was unexpected but explained by poor plant growth under water-saturated soil conditions. In another example, a calibrated SWAT model was used to determine sediment sources and evaluate a detention pond management strategy in a heavily developed urban watershed. Stream channel erosion was found to be higher than upland erosion and the implementation of a sediment detention pond showed that sediment exports could be reduced by up to 14%. Finally, the APEX model was used to examine two irrigation strategies in cascading rice paddy fields. Data from Okayama, Japan was used to develop a terraced hydrology model and predict irrigation management practice effects on water useage and soil and nitrogen exports to downstream waterbodies. The uncalibrated model showed that constant flooding irrigation produced higher crop yields but also increased sediment exports. Cycled flooding however showed reduced nitrogen exports. Determining the optimial management strategy depends upon user goals.

   Hydrophobicity is an important property of chemical compounds. The logarithm of the partition coefficient in 1-octanol/water (log P or log P_ow) is commonly used as an index of hydrophobicity. The highly hydrophobic chemical compounds which have large log P values may accumulate in the environment, causing general toxicity for wild organisms. In this paper, the relationships of aquatic toxicity and bioconcentration with log P and another hydrophobicity index, the logarithm of the membrane accumulation index, log P_M were explained. In addition, the brief results of our research on pesticide accumulation in Vietnam were described.

   Salt stress is one of the major abiotic stresses limiting rice production worldwide. Since the expansion of saline soil continues, there is a need to develop salt-tolerant rice varieties with high yields to ensure food security. Detecting quantitative trait loci (QTLs) for salt tolerance contributes greatly to breeding; however, limited studies have reported on the reproductive stage due to time-consuming and laborious processes. This review on QTL mapping for salt tolerance at the reproductive stage in rice shows that almost all QTLs explain small phenotypic variations scattered over the genome. Still, several QTLs were mapped in the same region on chromosomes 1, 2, and 6. The pyramiding of such QTLs is expected to improve tolerance and yield in elite varieties.

   Ophiocordyceps nutans is an entomoparasitic ascomycetes and has long been used extensively in traditional medicine in Asia because of its great aesculapian value. A field survey was undertaken at the Bidoup-Nui Ba National Park to evaluate the local community's environmental awareness. The results show that public knowledge about Cordyceps collection is significant. However, these fungus resources are expected to decline. The ecosystem for the fungus is changing negatively because the local community, which comprises ethnic minorities, is under considerable pressure due to its need for a sustainable livelihood, its low educational attainment, and hard life conditions The study focuses on environmental conditions that support in-situ and ex-situ conservation of this species, such as the temperature, humidity, and light, so that it can continuous to contribute to the sustainable management and enhancement of biodiversity in Bidoup-Nui Ba National Park.

   Recent studies have shown microplastics are also found on anchovy from Indonesia Sea. The anchovy is an abundant fish caught all year round because of the market demand in Asia. Generally, people do not like tiny anchovy pieces, and tend to consume anchovy as a whole, thus ingesting the digestive system as well. This study therefore broadens the perspective on data comparison from the previous study. In this study, four locations on the Indonesia Sea were assigned as the anchovy's sample origin. Subsequently, statistical analysis was conducted on comparison and regression for both microfiber and microfilm contamination found on each anchovy. The highest contaminated anchovy with microfiber (59.96±0.63 particle idv^-1) and microfilm (68±8.50 particle idv^-1) were discovered to be from Talisayan, East Kalimantan, while the lowest contamination on microfiber were from East Lombok (13±4.58 particle idv^-1), and no microfilm contamination was found on Alor's anchovy. Furthermore, a comparison was conducted between the anchovy's weight, length, microfiber, and microfilm, and the results showed no correlation (p > 0.05). This issue is therefore more challenging for future research, as another probability of accumulation is open. The bundance of microplastics contamination is not related to the anchovy's body mass, however, there is currently an exception for the variable of location, and only microfilm contamination has a correlation to the sample locations (r = 0.576).

   Malaria is still a serious cases all over the world especially in tropical country with a predict number 300-500 millions people infected per year. The resistence cases of these anti-malaria substance make a new effort to find the new strategy against malaria. This study aim to summarize the potential Piper genus as the source of potential antimalarial compound and recent research of callus induction in piper plant to obtain metabolites.The study of Piper genus represent the 11 Piper species were chemically studied and assayed against the plasmodium. The potential antimalarial compound isolates from several Piper genus were 20,60-Dihydroxy-40-methoxydihydro-chalcone,3-Farnesyl-p-hydroxybenzoic acid, Piperine, Chabamide, Benzoic acid derivatives, Guineensine, pellitorine, rachystamide B, sarmentine, and sermentosine, 5,8-Hydroxy-7-methoxyflavone, Prenylated hydroxybenzoic acid, 4-Nerolidylcatechol, Piperitone, Champor, and Viridiflorol (EO). An effort to propagate necessary antiplasmodial resources especially by callus induction has been conducted for 7 Piper species such as Piper betle, P. colubrinumm, P. crocatum, P. longum, P. nigrum, P. permucronatum and P. solmsianum to obtain higher content of secondary metabolites with a different plant growth hormone (PGR) supplementation while there are most of Piper genus have not been well studied. It conclude that callus culture could be the promising method to obtain antimalarial secondary metabolites as antimalarial.

   The research aimed to do the inventory and to reveal the diversity of top-soil insects related to the land utilization types in this company, i.e. conservation forest and oil-palm plantation. This study deployed survey method by collecting samples using pitfall traps. The result showed that the conservation forest and palm oil plantation were inhabited by 32 genera, 19 families, and 8 orders of top-soil insects. which mainly constituted of order Coleoptera, Hymenoptera, Collembola, Orthoptera, Diptera, Plecoptera, Hemiptera, and Dermaptera. The highest diversity (H'=3.07) was observed on nocturnal soil insects at the conservation forest, while diurnal soil insects showed the lowest diversity (H'=1.96) at the oil-palm plantation.

   Shiga toxin-producing Escherichia coli (STEC) bacteria, including the Escherichia coli O157, are described as pathogens producing toxin-like Stx₁ and Stx₂. These toxins become a significant virulence factor with a vital role in the outbreak of foodborne diseases worldwide. This study therefore aims to compile articles on STEC in several countries, using systematic review methods. Method: An online database on PubMed was accessed on 29^th October, 2020, to carry out the review, using STEC, E. coli O157, PCR, Stx₁, and Stx₂ as the keywords. This review utilized only full articles, written in English, and published within the past five years. Results: According to the results, there are nine related articles on this topic. In addition, primary E. coli O157 was found to produce toxins and greatly influence the pathogen's meat detection. All STEC strains were positive for Stx₁, while PCR detected Stx₂, and the whole-genome sequencing (WGS) provided forensic-level microbiological cross-contamination links from raw to ready-to-eat meat. Also, most of the articles showed cross-contamination occurred due to E. coli O157 bacteria's movement from the gastrointestinal tract to carcasses, and hygiene, as well as sanitation levels are the biggest causes of this contamination. Conclusion: E. coli O157 was identified not only on food like meat and spinach but also on non-food, including the environment. Improving hygiene and sanitation is a possible way to reduce the contamination of E. coli O157 on meat.

   This study aimed to evaluate the behavioral changes of Japanese quail under different temperature conditions. The experiment was carried on 36 days-old, 240 Japanese quails that were reared under three different temperature levels: (1) severe (38 °C), (2) near comfort zone (25 °C), and (3) ambient temperature (TA-30 °C). Each treatment consisted of 80 quails, one male and one female in each cage. The following behavioral traits were recorded in each treatment: (1) eating, (2) drinking, (3) aggressive activity, e.g., feather pecking, (4) other activities (quiet, resting, and no movement) for 10 seconds at 10 am, 12 pm, and 2 pm. The experiment lasted four days. The results showed that the Japanese quails displayed all observed behaviors in the different temperature conditions. The highest number of birds showed behaviors related to being quiet, resting, and no movement. There was a statistically significant difference in feeding behavior among the different temperature levels after 4 hours of measurements. The highest percentage of quails showed eating activity at ambient temperature treatment, whereas severe temperature recorded the lowest percentage of quails exhibiting this activity (p < 0.05). The percentage of quails showing drinking activity was the lowest at near comfort zone temperature and the highest at severe temperature (p < 0.05). The percentage of birds with aggressive activity was the highest in near comfort zone temperature (p = 0.058).