Field In Thailand Research Articles

Morphological and Molecular Characterization of Trichotylenchus dispersus (Nematoda: Dolichodoridae), a Newly Recorded Plant-Parasitic Nematode in the Rhizosphere Soil of Tomato Plants in Thailand

Trichotylenchus sp. is a migratory ectoparasitic nematode (PPN) that causes hypoplasia disease symptoms in economic plants, such as maize and banana. In this study, soil samples were collected from 6 locations in a tomato field in Khon Kaen Province, Thailand, for the purpose of nematode extraction using the Cobb’s sieving and flotation-centrifugation techniques. Morphological and molecular characterization of the collected PPN identified it as Trichotylenchus sp., a PPN not previously found in Thai tomato fields. Morphologically, the nematode has a C-shaped body, a rounded lip region, robust stylet and dorsal gland orifice located 2.0 ± 0.5 µm from the base of basal knobs. The tail is conically shaped, and the cuticle exhibits annulations with 3 incisures in the lateral field. The morphological characteristics observed closely matched Trichotylenchus sp. To confirm the identity, diagnosis was done using Polymerase Chain Reaction (PCR) molecular technique. Nematode DNA amplification was conducted with different target genes using primer sets AB28/TW81 for ITS1-5.8S-ITS2 and D2A/D3B for D2-D3 region of the 28S rRNA. The PCR amplification showed DNA fragments of approximately 950 and 800 bp, respectively. The sequences obtained were compared with those in the NCBI GenBank, which showed a 98.0 - 99.4 % identity match with Trichotylenchus dispersus specimens previously documented in China. In addition, the phylogenetic trees reiterated a nematode grouping with T. dispersus, 100 % bootstrap value. To the best of our knowledge, this is the first report of the presence of T. dispersus in the soils of tomato field in Thailand. This nematode is likely to become a major factor limiting tomato production yields if not properly managed. HIGHLIGHTS Six plant-parasitic nematodes (PPNs) were found to be associated with the tomato gown in field. A newly recorded PPN in the genus, Trichotylenchus, found in Thailand, has been documented in this study. Morphological and molecular characterization identified PPN as Trichotylenchus disperses. This is the first report on incidence of dispersus in a tomato field in Thailand. GRAPHICAL ABSTRACT

Driveway Detection for Weed Management in Cassava Plantation Fields in Thailand Using Ground Imagery Datasets and Deep Learning Models

Weeds reduce cassava root yields and infest furrow areas quickly. The use of mechanical weeders has been introduced in Thailand; however, manually aligning the weeders with each planting row and at headland turns is still challenging. It is critical to clear weeds on furrow slopes and driveways via mechanical weeders. Automation can support this difficult work for weed management via driveway detection. In this context, deep learning algorithms have the potential to train models to detect driveways through furrow image segmentation. Therefore, the purpose of this research was to develop an image segmentation model for automated weed control operations in cassava plantation fields. To achieve this, image datasets were obtained from various fields to aid weed detection models in automated weed management. Three models—Mask R-CNN, YOLACT, and YOLOv8n-seg—were used to construct the image segmentation model, and they were evaluated according to their precision, recall, and FPS. The results show that YOLOv8n-seg achieved the highest accuracy and FPS (114.94 FPS); however, it experienced issues with frame segmentation during video testing. In contrast, YOLACT had no segmentation issues in the video tests (23.45 FPS), indicating its potential for driveway segmentation in cassava plantations. In summary, image segmentation for detecting driveways can improve weed management in cassava fields, and the further automation of low-cost mechanical weeders in tropical climates can be performed based on the YOLACT algorithm.

Identification of bioactive compounds in cavalcade leaves for nematicidal activity against Hirschmanniella mucronata and Meloidogyne graminicola using LC-QTOF-MS

Hirschmanniella mucronata and Meloidogyne graminicola are the main plant-parasitic nematodes found in paddy fields in Thailand causing significant rice production yield losses. Although these nematodes are found widely in fields, an effective management method has not been documented. Here, we examined the nematicidal effects of different cavalcade leaf ages (1-, 2- and 3-month-old), used as aqueous extracts and soil amendments, on H. mucronata and M. graminicola. In vitro tests evidenced maximum mortality of H. mucronata (55.6–60.0%) in 50 mg ml−1 extract from all leaf ages, while mortality (65.9%) and hatchability (67.0%) of M. graminicola second-stage juveniles were observed in 50 mg ml−1 extract from 1-month-old leaves only. Moreover, aqueous extracts of cavalcade showed a repellent effect on both nematodes. Similarly, greenhouse experiments showed a significant reduction of H. mucronata population densities and reproduction of M. graminicola in soil amended with 0.5 and 1.0% (w/w) from each leaf age. LC-QTOF-MS analysis determined that three bioactive compounds, including quercetin, rutin, and kaempferol, are associated with the nematicidal activity of cavalcade against H. mucronata and M. graminicola. The information derived from this study indicates that the leaves of cavalcade are a source of promising phytonematicidals. This is the first study to assess and document its potential for nematicidal activity against H. mucronata and M. graminicola in Thailand. However, further research is needed to evaluate their efficacy under paddy field conditions.

Insights into soil nematode diversity and bacterial community of Thai jasmine rice rhizosphere from different paddy fields in Thailand.

Globally, phytonematodes cause significant crop losses. Understanding the functions played by the plant rhizosphere soil microbiome during phytonematodes infection is crucial. This study examined the distribution of phytonematodes in the paddy fields of five provinces in Thailand, as well as determining the keystone microbial taxa in response to environmental factors that could be considered in the development of efficient biocontrol tactics in agriculture. The results demonstrated that Meloidogyne graminicola and Hirschmanniella spp. were the major and dominant phytonematodes distributed across the paddy fields of Thailand. Soil parameters (total P, Cu, Mg, and Zn) were the important factors affecting the abundance of both nematodes. Illumina next-generation sequencing demonstrated that the levels of bacterial diversity among all locations were not significantly different. The Acidobacteriota, Proteobacteria, Firmicutes, Actinobacteriota, Myxococcota, Chloroflexi, Verrucomicrobiota, Bacteroidota, Gemmatimonadota, and Desulfobacterota were the most abundant bacterial phyla observed at all sites. The number of classes of the Acidobacteriae, Clostridia, Bacilli, and Bacteroidia influenced the proportions of Hirschmanniella spp., Tylenchorhynchus spp., and free-living nematodes in the sampling dirt, whereas the number of classes of the Polyangia and Actinobacteria affected the amounts of Pratylenchus spp. in both roots and soils. Soil organic matter, N, and Mn were the main factors that influenced the structure of the bacterial community. Correlations among rhizosphere microbiota, soil nematodes, and soil properties will be informative data in considering phytonematode management in a rice production system.

Antimicrobial Activities and Painting Application of Pigmented-Producing Actinobacteria Isolated from Rhizospheric Soils of Mosses (Taxithelium nepalense (Schwägr.) Broth. and Barbula indica (Hook.) Spreng.)

In the survey of biodiversity of actinobacteria associated with mosses (Taxithelium nepalense (Schwägr.) Broth. and Barbula indica (Hook.) Spreng.), certain strains of pigment producing actinobacteria were isolated and purified on SCA and incubated at 30°C for 1 week. Based on deep-shade color of actinobacterial pigments, 4 strains were collected and used for painting color preparation. To evaluate the antimicrobial activities, the crude extracts were prepared from 4 actinobacterial strains and tested with Escherichia coli PSRU-01 and Staphylococcus aureus PSRU-01. The results indicated that the crude extracts of C7, C13, C15 and D13 could not inhibit growth of E. coli PSRU-01, but S. aureus PSRU-01 was inhibited. Two fungal testers, including Colletotrichum sp. PSRU-01 and Fusarium sp. PSRU-01, were completely inhibited by the crude pigment extracts of C13, C15 and D13. Based on phylogenetic results, the actinobacterial strains were closely related to Streptomyces californicus (C7, 100% identity), Streptomyces bungoensis (C13, 99.8% similarity), Streptomyces humi (C15, 99.9% similarity), and Streptomyces rectiverticillatus (D13, 99.8% similarity). They also shared phenotypic characteristics with Streptomyces. The cultivated cells of actinobacteria on broken-milled rice were used for pigment extraction and followed by determination of the extracted pigments for mixing with acrylic color in the shade violet, green, orange and pink colors. Application of actinobacterial pigments in painting is the first report and it is an innovative utilization of actinobacterial pigments in non-scientific field in Thailand.

Fracture Characterization Explores Potential of Phra Wihan Formation, Thailand

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper IPTC 22845, “Fracture Characterization and Basement Reservoir Potential of Phra Wihan Formation in Southern Part of Uttaradit Province, Northern Thailand,” by Watcharapong Piewmoh, SPE, PTTEP, and Pitsanupong Kanjanapayont, Chulalongkorn University. The paper has not been peer reviewed. Copyright 2023 International Petroleum Technology Conference. Reproduced by permission. _ The complete paper describes the characterization of fractures in the Mesozoic sandstones of the Phra Wihan Formation in northern Thailand. Fracture characterization of outcrop analogs is important to determine the potential of subsurface reservoirs. The methodology used field study and petrography analysis to determine the relationship of fractures and other structures such as bedding planes and fold geometry. In addition, microstructure analysis can assist in the evaluation of a reservoir’s potential. Introduction Basement reservoir sandstones are one of the main targets in a mature onshore oil field in Thailand. But most basement reservoirs of the onshore Tertiary basin are pre-Tertiary and are associated with low quality. Prediction of reservoir quality in low-porosity and -permeability conditions requires an understanding of fractures in the subsurface. Outcrop analogs are key in characterizing fractured reservoirs. Geological Setting The tectonic evolution of Thailand is detailed in the complete paper. The country’s primary geological provinces are subdivided into the following five components, from west to east: - Sibumasu terrane - Inthanon zone - Sukhothai terrane - Nan and Sra Keao sutures - Indochina terrane The Sibumasu and Indochina terranes are major continental masses that collided during the Devonian-Triassic. Two subparallel suture zones exist along the convergence between the Sibumasu and Indochina terranes; one is an accretionary complex defined by the Inthanon zone. Another is a closed back-arc basin defined by the Nan and Sra Keao sutures. The Sukhothai terrane is an island-arc system formed along the margin of the Indochina terrane.

Baseline study of the morphological and genetic characteristics of Haemoproteus parasites in wild pigeons (Columba livia) from paddy fields in Thailand.

Haemoproteus columbae is a common haemosporidian parasite of wild pigeons (Columba livia) reported worldwide. In Thailand, the wild pigeon population is increasing due to paddy field monoculture. However, there are limited reports on the presence of H. columbae in these pigeon populations. The aim of the study was to characterize H. columbae in wild pigeons. A total of 87 wild pigeons were examined using microscopic and molecular methods. Haemoproteus columbae was detected in approximately 27.6% of pigeons and their morphological characteristics were described. The partial cytochrome b (cyt b) gene sequence of H. columbae was then characterized into three common lineages (HAECOL1, COLIV03, and COQUI05). By highlighting the morphologic and genetic characteristics of H. columbae commonly found in this population of pigeons, this study provides essential regional knowledge about haemosporidian parasites that could benefit future taxonomic and phylogeographic studies.

Occurrence of Heat-Resistant Mold Ascospores in Pineapple and Sugarcane Field Soils in Thailand.

Heat-resistant molds (HRMs) are important spoilage fungi of heat-processed fruit products worldwide. Ascospores of HRMs are widely distributed in the soil in which fruits are grown and are often found associated with raw fruit materials. To date, there is little available information on the distribution of HRMs in the soil and on their heat resistance. Thus, this study determined the presence and characterized the heat resistance of HRMs in soil samples from pineapple and sugarcane fields in Thailand. HRMs were detected in all soil samples, and the most dominant species was Aspergillus with 50-99.2% relative abundance. Other isolates, in descending order of frequency, were Penicillium, Talaromyces, Hamigera, and Paecilomyces. Then, 100 representative HRM isolates were identified based on a combination of morphological characteristics and ITS sequences. They were classified into 5 genera and 24 species. The heat resistance of ascospores aged 30 days produced by selected HRMs was qualitatively determined in a glucose-buffered solution. Based on their log reductions after heat shock at 75°C for 30 min, they were classified as less, moderately, or highly heat-resistant ascospores. HRMs belonging to A. chevalieri, A. denticulatus, A. siamensis, A. laciniosus, A. fennelliae, A. spinosus, Paec. niveus, H. pallida, and T. macrosporus produced high heat-resistant ascospores. In addition, soil physicochemical properties significantly influenced the prevalence of HRMs, depending on the fungal genus. The thermal resistance of ascospores was significantly and positively correlated to available phosphorus, whereas it was negatively correlated to soil pH. The results of this study confirmed the presence of HRMs in soils and potential HRM contamination, especially in fruits growing in acidic or high-nutrient soils, or both.

Practical recommendations for home-nebulized corticosteroid use in children aged ≤ 5 years with asthma: A review and advisory group consensus.

Despite nebulized budesonide being identified by the Global Initiative for Asthma report as a viable alternative to inhaled corticosteroids (ICS) delivered by pressurized metered-dose inhalers (pMDIs) with spacers, practical guidance on nebulized corticosteroid use in the pediatric population remains scarce. To review the current literature and provide practical recommendations for nebulized budesonide use in children aged ≤ 5 years with a diagnosis of asthma. A group of 15 expert pediatricians in the respiratory and allergy fields in Thailand developed Delphi consensus recommendations on nebulized budesonide use based on their clinical expertise and a review of the published literature. Studies that evaluated the efficacy (effectiveness) and/or safety of nebulized budesonide in children aged ≤ 5 years with asthma were assessed. AR patients. Overall, 24 clinical studies published between 1993 and 2020 met the inclusion criteria for review. Overall, results demonstrated that nebulized budesonide significantly improved symptom control and reduced exacerbations, asthma-related hospitalizations, and the requirement for oral corticosteroids compared with placebo or active controls. Nebulized budesonide was well tolerated, with no severe or drug-related adverse events reported. Following a review of the published evidence and group consensus, a treatment algorithm as per the Thai Pediatric Asthma 2020 Guidelines was proposed, based on the availability of medications in Thailand, to include nebulized budesonide as the initial treatment option alongside ICS delivered by pMDIs with spacers in children aged ≤ 5 years. ThNebulized budesonide is an effective and well-tolerated treatment option in children aged ≤ 5 years with asthma.

Bacillus velezensis S141, a soybean growth-promoting bacterium, hydrolyzes isoflavone glycosides into aglycones.

Bacillus velezensis S141, a plant growth-promoting rhizobacteria (PGPR), was isolated from a soybean field in Thailand. Previous studies demonstrated that S141 enhanced soybean growth, stimulating nodulation for symbiotic nitrogen fixation with soybean root nodule bacteria, including Bradyrhizobium diazoefficience USDA110. Isoflavone glycosides are produced in soybean roots and hydrolyzed into their aglycones, triggering nodulation. This study revealed that S141 efficiently hydrolyzed two isoflavone glycosides in soybean roots (daidzin and genistin) to their aglycones (daidzein and genistein, respectively). However, S141, Bacillus subtilis 168, NCIB3610, and B. velezensis FZB42 hydrolyzed isoflavone glucosides into aglycones. A BLASTp search suggested that S141 and the other three strains shared four genes encoding β-glucosidases corresponding to bglA, bglC, bglH, and gmuD in B. subtilis 168. The gene inactivation analysis of B. subtilis 168 revealed that bglC encoded the major β-glucosidase, contributing about half of the total activity to hydrolyze isoflavone glycosides and that bglA, bglH, and gmuD, all barely committed to the hydrolysis of isoflavone glycosides. Thus, an unknown β-glucosidase exists, and our genetic knowledge of β-glucosidases was insufficient to evaluate the ability to hydrolyze isoflavone glycosides. Nevertheless, S141 could predominate in the soybean rhizosphere, releasing isoflavone aglycones to enhance soybean nodulation.

Distribution and resistance of barnyardgrass to quinclorac in rice fields in Thailand

Background: In Thailand, Echinochloa crus-galli (L.) P. Beauv. (barnyardgrass) is the most problematic weed in rice. Quinclorac was first commercialized in 1997 in Thailand and became the primary herbicide option for barnyardgrass control. The intensive use of quinclorac in rice fields increases the risk of the evolution of resistant barnyardgrass. Objective: This study was conducted to survey the occurrence of quinclorac-resistant barnyardgrass in Thailand, investigate the levels of quinclorac resistance, and evaluate alternative control measures for quinclorac-resistant barnyardgrass. Methods: [...]

Decarbonizing the energy and industry sectors in Thailand by carbon capture and storage

In this paper, we evaluate decarbonization opportunities for the power and industry sectors in Thailand by carbon capture and storage (CCS). Stationary CO 2 sources from the power sector include coal-fired, natural gas-fired and waste-to-energy power plants. Stationary CO 2 sources from the industry sector include cement factories, refineries, iron and steel mills, petrochemical plants, and natural gas processing plants. Potential sites for subsurface CO 2 storage include oil fields, gas fields and saline aquifers in four offshore sedimentary basins (Songkhla, Pattani, Chumpon, Malay) and six onshore sedimentary basins (Fang, Phetchabun, Phitsanulok, Suphan Buri, Kamphaeng Saen, and Khorat). Data used in this study come from an extensive review of peer-reviewed journals, conference proceedings, and published reports. Results show that stationary CO 2 emission from the two sectors is 143 Mtpa consisting of 79 Mtpa from power plants and 64 Mtpa from industrial plants. The biggest CO 2 emission in the power sector comes from natural gas-fired power plants whereas that from the industry sector comes from cement factories. There is a total of 79 Gt of subsurface CO 2 storage capacity (mid case scenario) in Thailand, which is enough to store 554 years of CO 2 emission from stationary sources. Of this, 77.6 Gt (98%) comes from saline aquifers, 1.7 Gt (2%) from gas reservoirs, and only 0.05 Gt (<1%) from oil reservoirs. Therefore, saline aquifers are the most important sites for subsurface CO 2 storage. We propose using CCS clusters to reduce the overall project cost by using economies of scale. In a CCS cluster, multiple CO 2 sources are mapped to a common CO 2 sink by sharing the same CO 2 capture, transport, and injection network. A CO 2 source-sink mapping exercise results in the identification of six CCS clusters. For Cluster I, we propose a CCS demonstration project by capturing CO 2 emitted from cement factories near the city of Saraburi and transporting it to the nearby Sirikit oil field for CO 2 -enhanced oil recovery. This project can potentially recover 29 MMbbl of incremental oil. For Cluster II, CO 2 emitted from natural gas-ired power plants around Bangkok and petrochemical plants in Rayong is captured and stored in saline aquifers in the nearby Khorat Basin. For all other CCS clusters, emitted CO 2 can be stored in saline aquifers within a 200 km distance. However, detailed characterization of saline aquifers in Thai sedimentary basins such as caprock integrity, reservoir connectivity, net-to-gross etc., is required to materialize these CCS projects. • Stationary CO 2 emission in Thailand is 79 Mtpa from the power sector and 64 Mtpa from the industry sector. • There is 79.3 Gt of mid CO 2 storage capacity in Thailand, which is enough to store 567 years of CO 2 emission from stationary sources. • There is CO 2 -EOR/EGR potential 174 MMbbl from 53 oil and gas fields in Thailand. • However, most Thai gas fields are still under primary depletion and therefore not ready for CO 2 storage. • A source-sink mapping exercise has identified six CCS clusters where CO 2 sources within a cluster are mapped to CO 2 sinks within the same cluster for permanent storage.

The archaeomagnetic field recorded in ancient kiln walls in Si Satchanalai, Sukhothai

Archaeological dating is crucial in archaeology as it is a key to understand human history. However, traditional dating methods used by archaeologists such as potassium-argon dating and luminescence dating can provide ambiguous age results, e.g., argon loss during the dating returns young apparent ages. Therefore, I plan to establish an archaeomagnetic secular variation (ASV) curve to resolve this problem and use the ASV curve as an alternative tool to date archaeological artefacts. However, archaeomagnetic data in Thailand are absent from literature. Therefore, the ASV curve cannot be constructed from the archaeomagnetic data for this locality. To provide archaeomagnetic data to construct the ASV curve, the directions of the Earth’s magnetic field recorded in kiln walls from Ban Ko Noi (KN123, age 1,370 ± 100 A.D.), Si Satchanalai were measured. The mean declination and inclination of 49.6° and 32.6° with 95% confidence limit of 5.4° were determined from 10 samples from kiln KN123. Mean directions from this study were also compared with the directions of the Earth’s magnetic field in Thailand during 1,370 A.D. from the global archaeomagnetic field model ARCH3k.1. Declination and inclination from this study show significant departure from the field predicted by the ARCH3k.1 model.

Incidence and Characterization of Rice Root Nematodes, Hirschmanniella mucronata, from Rice Fields in Pathum Thani Province, Thailand

The rice root nematodes, Hirschmanniella oryzae and H. mucronata, are serious and widespread threats to global rice production, especially in tropical and subtropical zones. Reliable and efficient identification of these nematodes is vital to nematode control and management. In this current study, 36 soil or rice root samples were collected from rice fields located in Pathum Thani province and used for nematode extraction. The results demonstrated that Hirschmanniella sp. was found in all paddy fields, especially in Muang District, where RD47 rice cultivars were grown at soil pH of 5.9. Molecular identification based on the analysis of 28S rRNA and 18S-ITS1-1.58S genes revealed 98 – 99 % similarity to H. mucronata, and its phylogenetic trees were grouped with H. mucronata from Cambodia and Philippines. Likewise, the morphometric characterization revealed remarkable features of H. mucronata with long body (1,639 - 2,329 µm), long stylet (24 - 27 µm) and an obvious mucron at the end of terminus. Therefore, the main rice root nematode species found in Pathum Thani’s rice fields were H. mucronata.&#x0D; HIGHLIGHTS&#x0D; &#x0D; The rice root nematodes, Hirschmanniella, are presented the predominant plant-parasitic nematodes in rice cultivated areas of Pathum Thani province, Thailand&#x0D; Population densities of Hirschmanniella are encountered in rice roots than in soil, especially in RD47 rice cultivars grown in Muang District&#x0D; Both of morphological and molecular characterization illustrating the species of rice root nematodes were mucronate&#x0D; This is a first description on the molecular characterization of mucronata from rice fields in Thailand&#x0D; &#x0D; GRAPHICAL ABSTRACT

Paddy Rice Mapping in Thailand Using Time-Series Sentinel-1 Data and Deep Learning Model

The elimination of hunger is the top concern for developing countries and is the key to maintain national stability and security. Paddy rice occupies an essential status in food supply, whose accurate monitoring is of great importance for human sustainable development. As one of the most important paddy rice production countries in the world, Thailand has a favorable hot and humid climate for paddy rice growing, but the growth patterns of paddy rice are too complicated to construct promising growth models for paddy rice discrimination. To solve this problem, this study proposes a large-scale paddy rice mapping scheme, which uses time-series Sentinel-1 data to generate a convincing annual paddy rice map of Thailand. The proposed method extracts temporal statistical features of the time-series SAR images to overcome the intra-class variability due to different management practices and modifies the U-Net model with the fully connected Conditional Random Field (CRF) to maintain the edge of the fields. In this study, 758 Sentinel-1 images that covered the whole country from the end of 2018 to 2019 were acquired to generate the annual paddy rice map. The accuracy, precision, and recall of the resultant paddy rice map reached 91%, 87%, and 95%, respectively. Compared to SVM classifier and the U-Net model based on feature selection strategy (FS-U-Net), the proposed scheme achieved the best overall performance, which demonstrated the capability of overcoming the complex cultivation conditions and accurately identifying the fragmented paddy rice fields in Thailand. This study provides a promising tool for large-scale paddy rice monitoring in tropical production regions and has great potential in the global sustainable development of food and environment management.

Evaluation of CH4 Emission in Two Paddy Field Areas, Khonkaen and Ayutthaya, in Thailand

It is well known that submerged soils emit high levels of methane (CH4) due to oxygen deprivation and free iron oxide causing a quick reduction. However, there are other soil properties that control the reduction processes in soil, especially the amount of soil organic carbon (SOC). This study aimed to investigate the major factors controlling CH4 production potential (CH4PP) in Thai paddy fields. Two provinces, Ayutthaya, a clay soil region, and Khonkaen, a sandy soil region, were selected to represent a wide range of soil textures. Soil characteristic analysis pre- and post-incubation, and weekly gas detection in an incubation experiment over two months, was conducted. Stepwise multiple regression analysis was employed to analyze major soil factors controlling CH4PP. For the regional prediction of CH4PP, a map dataset of Ayutthaya and Khonkaen by the Land Development Department, Thailand, and a soil texture map (with intersected point data using the soil property map in ArcGIS) by OpenLandMap, were used. CH4PP was correlated with 1:10 pH, Fe2+, and water-soluble organic carbon (WSOC) measured after incubation. Although CH4PP showed no significant correlation with any soil properties measured before incubation, CH4PP was correlated with SOC, 1:10 electrical conductivity (EC), exchangeable ammonium (ExNH4), and sand content. It was thought that SOC and ExNH4 were related to organic matter decomposition, 1:10 EC was related to SO42− reduction and sand content was related to free oxides. Predicted regional CH4PP was similar in Ayutthaya and Khonkaen, although SOC, ExNH4 and 1:10 EC was higher, and sand content was lower in Ayutthaya than in Khonkaen. In both regions, the distribution of CH4PP corresponded to SOC, and CH4PP was lower with lower sand content and higher 1:10 EC. In clayey Ayutthaya, higher CH4PP was observed in the area with higher ExNH4. This indicates that soil properties other than soil texture and SOC influence CH4PP in the paddy fields in Thailand.

Regulatory stringency and behavior in a common pool resource game: Lab and field experiments

Reducing deforestation is one of the key actions necessary to mitigate global climate change. However, in developing countries where there is low enforcement of regulations, it is often difficult to motivate conservation. This paper applies a common pool resource game to look at whether or not changing the level of permitted resource use (i.e. regulatory stringency) affects behavior in a low-enforcement environment. The experiments are conducted in both the lab and the field in Thailand. We study the impact of varying the rule on permitted resource use on resource extraction, individual payoff and payoff distribution. Three levels of resource use are studied – strict, moderate, and relaxed, corresponding to disallowing usage, allowing a moderate amount of use, and allowing a generous amount of use respectively. We find that in our settings, imposing a strict rule is not always the best strategy to manage a common pool resource. In fact, allowing a higher level of resource use yields more desirable social (more equitable payoffs distribution), economic (individual payoff), and environmental (remaining resource stock) outcomes. Thus, our findings suggest that in a low enforcement environment, the design of the rule itself could help motivate conservation behavior by allowing resource users to realize the economic benefits of conservation.

Notes on the foraging and feeding behaviours of the Asian Openbill Stork (Anastomus oscitans)

The foraging and feeding behaviours of the Asian Openbill Stork (Anastomus oscitans) were observed in several paddy fields in Thailand, on food items not previously reported. Foraging and feeding techniques of the storks were similar to those described in the literature, except at one site where a peculiar new foraging behaviour was observed. Here, the storks fed on exotic Golden Apple Snails (Pomacea canaliculata) by using their bills to puncture the shells for extracting the soft snail bodies. The shells of large snails discarded by storks tended to be more damaged than those of small snails, due to the difficulty of extraction. Analyses of stork’s droppings and their regurgitated food showed that the bulk was of plant materials and shelled snails (mainly P. canaliculata and Filopaludina spp.). Adult storks tended to consume the whole soft bodies of the snails, including viscera, and sometimes the entire snails, including with their hard shells and opercula still attached. Although the storks could feed potentially on the entire snail body, the birds were seen to discard the male’s testes and female’s albumen glands of P. canaliculata at these feeding grounds, also evident in their regurgitates. Crushing of snail shells was not evident, but sometimes, pounding the shell and/or swallowing the entire shell and its operculum were supported by observations.

Insects identification with convolutional neural network technique in the sweet corn field

A method to identify the type of insects with accurate and precise results is of importance. Nowadays, an automatic object identification system with increased accuracy, improved speed, and less cost have been developed. Convolutional Neural Network (CNN) implementation for image identification or classification can be done by collecting large-scale datasets containing hundreds to millions of images to study the many parameters involved in the network. This research was conducted to develop and apply the CNN model to identify eight species of insects in the sweet corn field in Thailand. Those insects were Calomycterus sp., Rhopalosiphum maidis, Frankliniella williamsi, Spodoptera frugiperda, Spodoptera litura, Ostrinia furnacalis, Mythimna separata, and Helicoverpa armigera. The CNN model in this research was built with four convolutional layers, which consist of Conv2D, batch normalization, max pooling, dropout sublayer, and a fully-connected layer. in total, 5568 images were trained with 10 trials and different train attempts for each trial, were then tested with 40 images. The result shows that the CNN model has succeeded in identifying images of sweet corn insects with 80% up to 95% prediction accuracy for images with no background.

Practical considerations of nebulized corticosteroid in children with acute asthmatic exacerbation: A consensus.

Acute asthmatic exacerbation in children causes economic burdens both directly and indirectly. The GINA guideline does mention the use of inhaled or oral corticosteroids in the treatment of asthmatic exacerbation, it provides little practical guidance on the use of nebulized corticosteroid. To review and recommend the practical considerations in the use of nebulized corticosteroid in children with acute asthmatic exacerbation. This consensus was developed by a group of expert pediatricians in respiratory and allergy fields in Thailand. The recommendations were made based on a review of published studies and clinical opinions. The eligible studies were confined to those published in English, and randomized controlled trials and meta-analyses involving nebulized corticosteroids in asthmatic exacerbation in children aged between 1-18 years. There were 13 randomized controlled-trial studies published from 1998 to 2017. Nine of the 13 studies compared nebulized with systemic corticosteroid conducted in moderate to severe exacerbation, while the remaining four compared nebulized corticosteroid with placebo conducted in mild to severe exacerbation. The admission rate was significantly lower in severe exacerbation (one study) and pooled four mild to severe exacerbation studies comparing with placebo (p 0.022). Other clinical parameters were significantly improved with nebulized corticosteroid such as clinical scores, systemic corticosteroid/bronchodilator use, or shorter ER stays. Only one study used fluticasone, while the other 12 studies conducted by budesonide (92.31%). Nebulized corticosteroid may offer an effective therapeutic option for the management of acute exacerbation of asthma in all severities. Nebulized budesonide is the preferred corticosteroid.