Search Results (1,646)

Vigna radiata (L.) R. Wilczek, generally known as mung bean, is a crucial pulse crop in Southeast Asia that is renowned for its high nutritional value. However, its cultivation faces substantial challenges due to numerous abiotic stresses. Here, we investigate the influence of salt and drought stress on mung bean genotypes by evaluating its morpho-physiological traits and biochemical characteristics. This phenotypic analysis revealed that both salt and drought stress adversely affected mung bean, which led to reduced plant height, leaf senescence, loss of plant biomass, and premature plant death. Reactive oxygen species (ROS) production increased under these abiotic stresses. In response, to prevent damage by ROS, the plant activates defense mechanisms to scavenge ROS by producing antioxidants. This response was validated through morpho-physiological, histological, and biochemical assays that characterized KVK Puri-3 and KVK Jharsuguda-1 as salt and drought sensitive genotypes, respectively, and Pusa ratna was identified as a drought and salt tolerant genotype. Full article

The variation in the Asian summer monsoon anticyclone (ASMA) has long been of interest due to its effects on the weather and climate, as well as the vertical transport of pollutants in South Asia and East Asia. This study employs composite analysis to investigate the differences in the influences of sea surface temperature (SST) anomalies in the Western Pacific (WP) and the Indian Ocean (IO) on the ASMA and water vapor in the upper troposphere during summer. The underlying physical mechanisms were further explored. The results indicate that the warm SSTs in the WP have a greater impact on the intensity of the ASMA than those in the IO in summer. On the contrary, the cold SSTs in the IO have a greater impact on intensity of the ASMA than those in the WP in summer. The difference in the impact of SSTs in the WP and IO on the boundaries of the ASMA is relatively small. During positive SST anomalies in the WP, the increase in tropospheric temperature in South Asia and the strengthening of Walker circulation in the WP both contribute to the enhancement of the ASMA. The variations in tropospheric temperature and Walker circulation caused by positive SST anomalies in the IO are similar to those in the WP, except that the rising branch of the Walker circulation is located in the central and western IO. The decrease in SST in the WP region causes insignificant changes in the ASMA. During the cold SST period in the IO, the significant decrease in tropospheric temperature and the weakening of the Walker circulation in the IO region lead to a significant decrease in the intensity of the ASMA at the southern ASMA. When the SST in the WP and IO regions is warmer, the high value centers of water vapor in the troposphere generally coincide with the high value centers of temperature, accompanied by enhanced convection, significantly increasing the water vapor south of the ASMA. The anomalous sinking movement in the Western Pacific leads to relatively small changes in water vapor from the near-surface to 150 hPa over the southeast of the ASMA. Full article

In July 2017, a family of three members, a 46-year-old male, a 45-year-old female and their 8-year-old daughter, returned to South Africa from Thailand. They presented symptoms consistent with mosquito-borne diseases, including fever, headache, severe body aches and nausea. Mosquito bites in all family members suggested recent exposure to arthropod-borne viruses. Dengue virus 1 (Genus Orthoflavivirus) was isolated (isolate no. SA397) from the serum of the 45-year-old female via intracerebral injection in neonatal mice and subsequent passage in VeroE6 cells. Phylogenetic analysis of this strain indicated close genetic identity with cosmopolitan genotype 1 DENV1 strains from Southeast Asia, assigned to major lineage K, minor lineage 1 (DENV1I_K.1), such as GZ8H (99.92%) collected in November 2018 from China, and DV1I-TM19-74 isolate (99.72%) identified in Bangkok, Thailand, in 2019. Serum samples from the 46-year-old male yielded a virus isolate that could not be confirmed as DENV1, prompting unbiased metagenomic sequencing for virus identification and characterization. Illumina sequencing identified multiple segments of a mammalian orthoreovirus (MRV), designated as Human/SA395/SA/2017. Genomic and phylogenetic analyses classified Human/SA395/SA/2017 as MRV-3 and assigned a tentative genotype, MRV-3d, based on the S1 segment. Genomic analyses suggested that Human/SA395/SA/2017 may have originated from reassortments of segments among swine, bat, and human MRVs. The closest identity of the viral attachment protein σ1 (S1) was related to a human isolate identified from Tahiti, French Polynesia, in 1960. This indicates ongoing circulation and co-circulation of Southeast Asian and Polynesian strains, but detailed knowledge is hampered by the limited availability of genomic surveillance. This case represents the rare concurrent detection of two distinct viruses with different transmission routes in the same family with similar clinical presentations. It highlights the complexity of diagnosing diseases with similar sequelae in travelers returning from tropical areas. Full article

Gottschelia, collected for the first time in Indochina, inspired an attempt to review the genus phylogeny to identify a more precise position of Indochinese plants. The genetic distance between African and Asian populations of G. schizopleura sensu lato was confirmed. The two groups should be treated as different species. A new combination, G. microphylla comb. nov., has been proposed for Asian plants. Aside from molecular genetics, distinguishing this species from the presumable strictly African G. schizopleura is also possible by morphological characteristics, as well as by its distribution. At the same time, at least three groups are distinguished among Asian haplotypes of G. microphylla, each of which can be interpreted as a species or, at least, subspecies. A morphological description, intravital photographs of the general habitat, and details of the morphological structures are provided. The position of Gottschelia in the phylogenetic schema of Jungermanniales does not allow us to attribute it to any of the known families and forces us to describe a new family, Gottscheliaceae, which is phylogenetically somewhat related to the Chaetophyllopsidaceae re-evaluated here and very different from Gottscheliaceae morphologically. Full article

Danio rerio is a small tropical freshwater fish, also known as Brachydanio rerio and commonly referred to as zebrafish, described for the first time in 1822 by Francis Hamilton in the Ganges River but widespread throughout the entire Great Himalayan region of Southeast Asia [...] Full article

Ecosystem resilience, the ability of an ecosystem to recover from disturbances, is a critical indicator of environmental health and stability, particularly under the impacts of climate change and anthropogenic pressures. This study focuses on the Three-River Headwater Region (TRHR), a critical ecological area for East and Southeast Asia, often referred to as the “Water Tower of China”. We used the Normalized Difference Vegetation Index (NDVI) as a proxy for vegetation growth and productivity and calculated Critical Slowing Down (CSD) indicators to assess the spatiotemporal dynamics of grassland ecosystem resilience in the TRHR from 1984 to 2021. Our research revealed a sustained improvement in ecosystem resilience in the TRHR starting in the late 1990s, with a reversal in this trend observed after 2011. Spatially, ecosystem resilience was higher in areas with greater precipitation and higher vegetation productivity. Temporally, changes in grazing intensity were most strongly correlated with resilience dynamics, with explanatory power far exceeding that of NDVI, temperature, and precipitation. Our study underscores the importance of incorporating ecosystem resilience into assessments of ecosystem function changes and the effectiveness of ecological conservation measures, providing valuable insights for similar research in other regions of the world. Full article

This study analyses macroeconomic trends in Southeast Asian countries and their implications for climate change, focusing on urbanisation, GDP per capita, energy intensity, FDI, inflation, and trade. Using panel data from 1970 to 2020, we investigate climate change drivers across Indonesia, Malaysia, the Philippines, Singapore, and Thailand through panel ARDL with PMG and MG analyses, along with Hausman tests. Our results highlight the need for tailored urbanisation policies for sustainability, as the consistent positive correlation between GDPs per capita and emissions, underscores the challenge of decoupling economic growth from emissions. Urbanisation’s varying impact calls for proactive planning, and mixed FDI results suggest nuanced investment approaches aligned with sustainability. Inflation’s negative impact hints at environmental benefits during price increases, necessitating integrated economic and climate policies. The positive relationship between trade openness and emissions emphasises the need for eco-conscious trade agreements to mitigate emissions from industrial activity. Our study stresses the importance of considering macroeconomic heterogeneity in crafting climate policies. Policymakers must adopt multifaceted approaches that prioritise sustainability across economic growth, energy efficiency, technology adoption, and trade to balance development with environmental preservation. This approach enables Southeast Asian countries to contribute effectively to global climate change mitigation. Full article

This study presented an assessment of climate extremes in the Southeast Asia (SEA) region, utilizing downscaled climate projections from the Coupled Model Intercomparison Project Phase 6 (CMIP6) Global Climate Models (GCMs). The study outputs uncovered statistically significant trends indicating a rise in extreme precipitation and temperature events throughout SEA for both the near-term (2021–2060) and long-term (2061–2100) future under both SSP245 and SSP585 scenarios, in comparison to the historical period (1950–2014). Moreover, we investigated the seasonal fluctuations in rainfall and temperature distributions, accentuating the occurrence of drier dry seasons and wetter rainy seasons in particular geographic areas. The focused examination of seven prominent cities in SEA underscored the escalating frequency of extreme rainfall events and rising temperatures, heightening the urban vulnerability to urban flooding and heatwaves. This study’s findings enhance our comprehension of potential climate extremes in SEA, providing valuable insights to inform climate adaptation, mitigation strategies, and natural disaster preparedness efforts within the region. Full article

Castanopsis hystrix, a precious tree species in Southeast Asia, has the advantages of rapid growth and high-quality wood materials. However, there are problems such as its long breeding cycle and low efficiency, and being time-consuming, which greatly restricts the industrial development of C. hystrix. Performing genome selection (GS) for growth and wood traits for the early selection of superior progeny has great significance for the rapid breeding of new superior varieties of C. hystrix. We used 226 clones in the main distribution and 479 progenies within 23 half-sib families as experimental materials in this study. Genotyping datasets were obtained by high-throughput re-sequencing technology, and GS studies were conducted on the growth (tree height (H), diameter at breast height (DBH)) and wood (wood density (WD), fiber length (FL), and fiber length–width ratio (LWR)) traits. The coefficient of variation (CV) of five phenotypic traits ranged from 10.1% to 22.73%, the average CV of growth traits was 19.93%, and the average CV of wood traits was 9.72%. The Pearson correlation coefficients between the five traits were almost all significantly positive. Based on the Genomic Best Linear Unbiased Prediction (GBLUP) model, the broad-sense heritabilities of growth traits were higher than those of wood quality traits, and the different number of SNPs had little effect on the heritability estimation. GS prediction accuracy first increased and then reached a plateau at around 3K SNPs for all five traits. The broad-sense heritability of these five traits was significantly positively correlated with their GS predictive ability (r = 0.564, p < 0.001). Bayes models had better GS prediction accuracy than the GBLUP model. The 15 excellent progeny individuals were selected, and their genetic gain ranged from 0.319% to 2.671%. These 15 superior offspring individuals were 4388, 4438, 4407, 4468, 4044, 4335, 4410, 4160, 4212, 4461, 4052, 4014, 4332, 4389, and 4007, mainly from three families F5, F6, and F11. Our research lays out the technical and material foundation for the rapid breeding of new superior varieties of C. hystrix in southern China. Full article

The Tonle Sap Lake (TSL) landscape is a region of vast natural resources and biological diversity in the heart of Southeast Asia. In addition to serving as the foundation for a highly productive fisheries system, this landscape is home to numerous globally threatened species. Despite decades of recognition by several government and international agencies and the fact that nine protected areas have been established within this region, natural land cover such as grasslands have experienced considerable decline since the turn of the century. This project used local expert knowledge to train and validate a random forest supervised classification of Landsat satellite imagery using Google Earth Engine. The time series of thematic maps were then used to quantify the conversion of grasslands to croplands between 2004 and 2023. The classification encompassed a 10 km buffer surrounding the landscape, an area of nearly 3 million hectares. The average overall accuracy for these thematic maps was 82.5% (78.5–87.9%), with grasslands averaging 76.1% user’s accuracy. The change detection indicated that over 207,281 ha of grasslands were lost over this period (>59.5% of the 2004 area), with approx. 89.3% of this loss being attributed to cropland expansion. The results of this project will inform conservation efforts focused on local-scale planning and the management of commercial agriculture. Full article

Drynaria roosii Nakaike, a fern widely distributed in China and some countries in Southeast Asia, is a commonly used herbal medicine in tonic diets and Chinese patented medicine. The metabolites of its dried rhizomes are easily affected by the epiphytic pattern, whether on rock tunnels (RTs) or tree trunks (TTs). The current research focused on rhizomes from these two patterns, RTs and TTs (further divided into subclasses TA, TB, TC, and TD, based on trunk differences) and conducted a widely targeted metabolomics analysis. A total of 1435 components were identified across 13 categories, with flavonoids, amino acids, and their derivative, lipids, identified as the main components. They accounted for 19.96%, 12.07%, and 12.14% of all metabolites, respectively. The top five flavonoids in TB were eriodicty-ol-7-O-(6″-acetyl)glucoside, quercetin-3-O-sophoroside (baimaside), dihydrochar-cone-4′-O-glucoside, morin, and hesperetin-7-O-glucoside, with relative contents 76.10, 24.20, 17.02, 15.84, and 14.64 times higher than in RTs. Principal component analysis revealed that samples with different epiphytic patterns clustered into five groups. The RT patterns revealed unique metabolites that were not detected in the other four epiphytic species (TA, TB, TC, and TD), including 16 authenticated metabolites: 1 alkaloid, 1 amino acid derivative, 7 flavonoids, 2 lignans, 1 lipid, 1 alcohol, 1 aldehyde, and 2 phenolic acids. These differences in epiphytic patterns considerably affected the accumulation of both primary and secondary metabolites. The comparison of diversity between RTs and TTs can guide the selection of a cultivation substance and the grading of collective rhizomes in the wild. This comprehensive analysis of D. roosii rhizome metabolites also offers fundamental insights for identifying active components and understanding the mechanisms underlying their potential pharmacological activities. Full article

The unusual daytime F-region Field-Aligned Irregularities (FAIs) were observed by the HCOPAR and the satellites at low latitudes on 13 June 2022. These irregularities survived from night-time to the following afternoon at 15:00 LT. During daytime, they appeared as fossil structures with low Doppler velocities and narrow spectral widths. These characteristics indicated that they drifted along the magnetic field lines without apparent zonal velocity to low latitudes. Combining the observations of the ICON satellite and the Hainan Digisonde, we derived the movement trails of these daytime irregularities. We attributed their generation to the rapid ascent of the F-layer due to the fluctuation of IMF Bz during the quiet geomagnetic conditions. Subsequently, the influence of the substorm on the low-latitude ionosphere was investigated and simulated. The substorm caused the intense Joule heating that enhanced the southward neutral winds, carrying the neutral compositional disturbances to low latitudes and resulting in a negative storm effect in Southeast Asia. The negative storm formed a low-density circumstance and slowed the dissipation of the daytime FAIs. These results may provide new insights into the generation of post-midnight irregularities and their relationship with daytime fossil structures. Full article

Dengue fever is an urban, tropical, and semi-tropical disease transmitted by Aedes aegypti and Aedes albopictus mosquitoes. One significant challenge lies in identifying reliable intra-urban indicators of their densities. Following standardized sampling protocols that adequately take into account the spatial heterogeneity of the geographical contexts which may influence mosquito habitats is therefore fundamental to compare studies and follow such relevant indicators. We develop a method for subdividing urban territory based on environmental factors which are susceptible to influence the density of potential mosquito-breeding containers. Indeed, the presence of these containers, most of which are produced by humans, is essential for the renewal of mosquito populations. Land-uses variables and their local variations are determinant in this analysis. Starting from each building and its immediate neighborhood described in terms of vegetation and open area, we computed the local landscape metrics of a million buildings in Bangkok. We then used segmentation and clustering techniques to generate homogeneous zones based on these components and physiognomy. Subsequently, a classification process was conducted to characterize these zones according to land-use and composition indicators. We applied this automatic clustering method within Bangkok’s urban area. This classification built from hypotheses on the existence of links between the types of urban landscape and the presence of outdoor containers must be evaluated and will serve as a foundation for the spatial sampling of field studies for vector surveillance in Bangkok. The choice of sampling zones, even if it must be based on an administrative division due to the decentralization of health agencies in Bangkok, can then be enriched by this new, more functional division. This method, due to the genericity of the factors used, could be tested in other cities prone to dengue vectors. Full article

Programmed cell death-1 (PD1) inhibitors, a form of immune checkpoint inhibitor, are efficacious for metastatic melanoma but are associated with cutaneous adverse reactions (CARs). Studies in Europe and North America showed that CARs are associated with an increased overall survival. However, studies from Asia showed mixed results. There is a paucity of data regarding the efficacy of PD1 inhibitors and the effect of CARs on overall survival from Southeast Asia. A retrospective study of patients in the National Cancer Centre Singapore who were diagnosed with melanoma between 2015 and 2020 was conducted. Patients were included in the study if they had stage IV melanoma (advanced melanoma). Sixty-two patients were included in the study. The median age was 62.5 years and acral melanoma was the commonest subtype. Forty-three patients received PD1 inhibitors. Comparing patients who did not receive PD1 inhibitors to patients who received PD1 inhibitors, the former had a median overall survival of 6 months (95% CI: 5.07, 6.93), whereas the latter had a median overall survival of 21 months (95% CI: 13.33, 28.67; p < 0.001) (Hazard ratio 0.32; 95% CI: 0.16, 0.63; p = 0.001). Amongst patients who received PD1 inhibitors, patients who developed CARs had a greater median overall survival of 33 months (95% CI: 17.27, 48.73) compared to 15 months (95% CI: 9.20, 20.80; p = 0.013) for patients who did not (HR 0.29; 95% CI: 0.098, 0.834; p = 0.022). This study provides insight into the outcomes of metastatic melanoma in Singapore, and adds to the body of evidence supporting the use of PD1 inhibitors in Asians. Full article

The “SmartCaregivers” 1.0 mobile application is a beacon of hope for caregivers (CG) in rural areas, often facing limited access to facilities and support. This study, conducted from February to August 2021, aimed to comprehensively analyze the need for developing a database system and a mobile application tailored to enhance caregiver support and resource management for long-term dependent individuals in the rural areas of Maha Sarakham province, Thailand. The research followed a rigorous research and development (R & D) approach, specifically the ADDIE model (analysis, design, development, implementation, and evaluation). Data were collected from 402 caregivers and 10 key informants through surveys and interviews, as well as from 402 caregivers during the implementation and evaluation phases. The application’s impact was assessed using a quasi-experimental design with a one-group pre–post-test, and its acceptance was evaluated through the technology acceptance model (TAM). The application significantly improved caregivers’ knowledge scores, with a mean increase from 10.49 ± 2.53 to 12.18 ± 2.76 post-intervention. High scores for perceived usefulness (4.36 ± 0.62) and ease of use (4.31 ± 0.59) reassure the audience about the application’s effectiveness in providing rapid access to health information, aiding decision-making, and improving care coordination. The system quality was also highly rated, with users appreciating the variety of functions and structural design. This potential for transformation and improvement instills hope and optimism for the future of caregiving in rural areas. Full article