Program of International Symposium on Environmental and Life Science FY 2021 held at Okayama University with online presentations from abroad on January 24th, 2022

   Reproduction is required to give rise to sustainable environmental management for human welfare and livestock production. The well-being of humans and animals could be achieved by scientists' contributions to development, innovation, problem-solving, and combining other subdisciplines of biology. In Indonesia, veterinary reproductive specialists advocate reproduction as a prime concern in the health, economic, and social fields. The advancement of reproductive biology will always depend on technological advances. Furthermore, the outcome of the research on reproduction will contribute to the health improvement of both livestock and endangered animals, with infertility treatment as an example. This research will give a general overview of how important it is to keep advancing technology to support the concept of a sustainable and high-quality environment.

   Quercetin, one of the most ubiquitous flavonoids, shows beneficial effects for human health. In general, quercetin exists in foodstuffs as glycoside forms. Quercetin glycosides can be degraded by the gut microbiota into ring fission compounds, such as 3,4-dihydroxyphenylacetic acid, 3-hydroxyphenylacetic acid, 3,4-dihydroxybenzoic (protocatechuic) acid and hippuric acid. This paper reviews the recent findings about these catabolites, including their biological activities as well as chemical characteristics. This paper also summarizes their health-promoting potentials, thus presenting evidence for them improving our comprehension of the practicality of quercetin glycosides.

Program of the Second Debrief Meeting on Education and Research FY2021 held at Okayama University with online presentations from abroad on January 25th, 2022

   In recent years, global warming has been progressing due to increases in greenhouse gas concentrations in the atmosphere. Greenhouse gas emissions from agro-ecosystems impact global warming. In particular, CH₄ and N₂O are mainly emitted by agricultural activities. Rice cultivation is a primary source of CH₄. Reducing CH₄ and N₂O emissions in paddy fields is essential for mitigating global warming. Water management impacts the production of greenhouse gases in paddy fields. To understand the dynamics of soil-produced greenhouse gases, determining soil gas concentrations is necessary. In this study, Rice (Oryza sativa L., cultivar Kinuhikari) was grown under different water management practices, and rice yield and greenhouse gas (CH₄, CO₂, N₂O) production in soil were measured to investigate the effects of water management. Soil gas concentrations of CH4 were high when the soil was flooded and low when the soil was drained. On the other hand, N₂O concentration was low when the soil was flooded and high when the soil was drained. This may be because NO_3- was produced in soil by nitrification. Therefore, soil water management may play a key role in mitigating greenhouse gases in paddy fields.

   Principal component analysis (PCA), cluster analysis (CA), and water quality index (WQI) were used in this study to analyze the Saigon River water-quality monitoring data collected monthly from April 2016 to May 2020. The calculated WQI indicated that the water quality of the Saigon River improved from 2016 to 2020, but it was still polluted by ammonium (N-NH₄⁺), dissolved oxygen (DO), and coliforms, by which the water in the rainy season was more contaminated than that of the dry season. Three components of PCA showed 58.68% of the variance in the data set. The CA grouped the water quality into 3 clusters (upstream, midstream, and downstream) in both dry and rainy seasons.

   Ecosystem-based adaptation (EbA) harnesses biodiversity and ecosystem services to reduce vulnerability and build resilience to climate change. Intact coastal forests on dunes and adjacent sandy areas show important protective functions. To prove the possibility of EbA in North Central of Vietnam, we piloted the restoration of coastal forests with native species. This study aims to examine the growth performance of 10 species planted in 2019. The survival rates were over 80% in 3 pilot sites 3 months after planting. Melaleuca cajuputi had the highest survival rate after the 2020 long-term drought and historic flood. The research findings indicated that M. cajuputi and V. mangachapoi outperformed other species.

   Stingless bees are a group of social bees that belong to family Apidae and widely distributed in tropic and subtropic region. Due to good quality of honey and propolis produced by stingless bees, stingless bee keeping activity, also known as meliponiculture, became popular. The present study was done by narrative reviewed relevant papers to discuss the potential of integration between meliponiculture and agricultural holding, as a strategy to accelerate progress towards the Sustainable Development Goals (SDGs). This review provides recent scientific studies in development of integration of stingless bee keeping and farming activity, which give supplementary sources of income for farmers.

   In Vietnam, leaf blight disease is caused by Xanthomonas axonopodis pv. allii on green onion. Therefore, the purpose of this research was to find bio-solution with the beneficial rhizomatous fungus. The results showed that when treated at seven days before inoculation, Penicillium had the ability to reduce leaf blight severity up to 82.99% at day three after inoculation. Moreover, the value of enzyme PAL gained 25.22 μg/protein/min at 6 hours after inoculation. In addition, results also showed that Penicillium treatment at two days before inoculation reduced disease severity by 75% and 68.75% at days two and three after inoculation, respectively. Similarly, the PAL value of this treatment was 25.66 g/protein/min.

   In this study, we use a generalized lasso to fit spatially varying coefficient models to the case of predictor variables with both numerical and categorical scales. We constructed the generalized lasso model with two 𝐿₁ penalties: one was to link some categories within one categorical predictor, and the other was to link a corresponding categorical predictor between adjacent regions. Then, we applied the proposed method to a province-wise analysis of house sales price data on Java Island, Indonesia, to the original data without concatenation between categories for each categorical predictor. An optimal model is obtained in which categories and regions with the same effect are pooled.