Different Areas Of Thailand Research Articles

A description of a new species of Mongolodiaptomus Kiefer, 1937 (Copepoda, Calanoida, Diaptomidae) from Thailand with an up-to-date key to the genus.

The genus Mongolodiaptomus is widely distributed in stagnant water bodies in Southeast Asia. During a comprehensive collection of freshwater copepods from different areas in Thailand, a previously unknown species of calanoid copepod, Mongolodiaptomusphutakaensis sp. nov., was recorded. Representatives were found in a natural swamp located in the Kok Phutaka community forest in Khon Kaen Province, northeastern Thailand. The new species belongs to the "M.loeiensis species group" and most closely resembles M.loeiensis and M.mekongensis by having a distinct shape of the second exopodal segment of the male right P5, with enlarged proximal and distal parts of the outer margin as well as a bent and twisted principal lateral spine. The new species can be distinguished from its congeners by various characters in the males. The ventral surface of the right caudal ramus has two chitinous teeth and two knobs. The intercoxal plate is slightly produced distally and without any spine. The right P5 basis lacks a hyaline membrane on the inner margin but has a distinct spur-like chitinous process at the mid-distal margin on the posterior surface. The left P5 basis has a thin, longer hyaline lamella on the inner margin. The new species is rare, having been observed in only one out of approximately 5,000 surveyed locations in Thailand. A detailed morphological comparison and an up-to-date key to the Mongolodiaptomus species are presented. Their taxonomic characters, interspecies relationships, and biogeography are discussed.

First records of penicillate millipedes (Diplopoda, Polyxenidae) from Thailand, with descriptions of two new species.

Two new species are described from the family Polyxenidae. Monographis panhai sp. nov. and Unixenus thailandicus sp. nov. represent the first records of their respective genera in Thailand. Monographis panhai sp. nov. shows distinct morphological differences in the arrangement of sensilla in the antennomere VI, as well as in the structures of the labrum and the claw. Collections from different areas of Thailand showed that not only is it widespread but also exhibits geographic variation in morphology. Unixenus thailandicus sp. nov. exhibits sexual dimorphism in the number of conical sensilla on the lateral palp, with 24 in males and 22 in females, differing from the typical count of 13 within the genus.

Simultaneous Confidence Intervals for All Pairwise Differences between Means of Weibull Distributions

The Weibull distribution is a continuous probability distribution that finds wide application in various fields for analyzing real-world data. Specifically, wind speed data often adhere to the Weibull distribution. In our study, our aim is to compare the mean wind speed datasets from different areas in Thailand. To achieve this, we proposed simultaneous confidence intervals for all pairwise differences between the means of Weibull distributions. The generalized confidence interval (GCI), method of variance estimates recovery (MOVER), and a Bayesian approach, utilizing both gamma and uniform prior distributions, are proposed to construct simultaneous confidence intervals. Through simulations, we find that the Bayesian highest posterior density (HPD) interval using a gamma prior distribution demonstrates satisfactory performance, while the GCI proves to be a viable alternative. Finally, we applied these proposed approaches to real wind speed data in northeastern and southern Thailand to illustrate their effectiveness and practicality.

Geographic Variation in Testicular Morphometrics, Androgen Receptor Expression and Anti-Müllerian Hormone Levels in the Intermediate Roundleaf Bats across Distinct Regions in Thailand.

The hipposideros larvatus (intermediate roundleaf bat) is one of the insectivorous bats which has an agro-ecological role as a controller of the insect population. The reproductive patterns of H. larvatus are intricately linked to its ecological role and survival. An understanding of the testicular morphology can contribute to conservation for this species particularly in areas where its populations might be declining or under threat. However, these bats may also be associated with zoonotic diseases which can have significant public health implications. The aims of the study were to examine the morphological data as well as the expression of the androgen receptor (AR) and anti-Müllerian hormone (AMH) in the male reproductive organs of H. larvatus from different areas of Thailand and at different sampling periods. Their testes were processed for histological investigation and immunohistochemistry for AR and AMH. The results showed differences among the various sampling areas and different sampling periods, which suggested seasonal breeding characteristics. The higher testicular morphometric data were observed in H. larvatus from the Dong Phayayen (DY) and Chiang Dao (CD) areas during June, while the size of seminiferous tubules decreased thereafter. High AR immunostaining was noticed when the testicular morphometric data were higher in DY bats during June. On the other hand, low AR was observed in bats during August and September, which was concomitant with the decreases in seminiferous tubule size and germinal epithelial height. The results suggest a potential correlation between AR immunostaining and the active phase of testicular functions in H. larvatus during June which may imply the involvement of AR with the enhancement of testicular activity. Conversely, the low expression of AR may contribute to the upregulation of AMH in the testes and may indicate lower testicular activity in H. larvatus in Thailand.

Estimation of the Confidence Interval for the Ratio of the Coefficients of Variation of Two Weibull Distributions and Its Application to Wind Speed Data

The Weibull distribution, one of the most significant distributions with applications in numerous fields, is associated with numerous distributions such as generalized gamma distribution, exponential distribution, and Rayleigh distribution, which are asymmetric. Nevertheless, it shares a close relationship with a normal distribution where a process of transformation allows them to become symmetric. The Weibull distribution is commonly used to study the failure of components and phenomena. It has been applied to a variety of scenarios, including failure time, claims amount, unemployment duration, survival time, and especially wind speed data. A suitable area for installing a wind turbine requires a wind speed that is both sufficiently high and consistent, and so comparing the variation in wind speed in two areas is eminently desirable. In this paper, methods to estimate the confidence interval for the ratio of the coefficients of variation of two Weibull distributions are proposed and applied to compare the variation in wind speed in two areas. The methods are the generalized confidence interval (GCI), the method of variance estimates recovery (MOVER), and Bayesian methods based on the gamma and uniform priors. The Bayesian methods comprise the equal-tailed confidence interval and the highest posterior density (HPD) interval. The effectiveness of the methods was evaluated in terms of their coverage probabilities and expected lengths and also empirically applied to wind speed datasets from two different areas in Thailand. The results indicate that the HPD interval based on the uniform prior outperformed the others in most of the scenarios tested and so it is suggested for estimating the confidence interval for the ratio of the coefficients of variation of two Weibull distributions.

Synchrotron radiation study on Thai reddish glass

It is well-known that red glass has been used as a decorative glass in Thailand for hundred years. Pieces of reddish decorative glasses (Ancient Burmese Glass: ABG, Ancient Thai Glass: ATG, and Modern Imported Glass: MIG) have been collected from different areas in Thailand. The elemental composition and morphology of these samples have been examined using scanning electron microscopy equipped with energy dispersive X-ray spectroscopy (SEM-EDS) and proton-induced X-ray emission spectroscopy (PIXE). The binding components have been analyzed using infrared spectroscopy based on synchrotron radiation (SR IR). PIXE results indicate a presence of trace elements which is beyond the limit of detection of EDS. It has been found that ABG and MIG are soda-silicate glass, while ATG is lead-based glass. The red coloration in ABG, ATG, and MIG is affected by the contents of Cu, Cd, and Se. It is also found that ABG and MIG have been produced using crucible vessel and glass-making furnace, respectively, while ATG has been produced using either crucible vessel or glass-making furnace. With the high brightness of the synchrotron source, SR IR can analyze the sample with a high spatial resolution of 20 × 20 µm2. SR IR results confirm the presence of inorganic and organic functional groups in glass samples which exhibit distinctive peaks for different types of glass.

The utilization of mangosteen pericarp extract for anticoccidial drug replacement in broiler feed

ABSTRACT The use of anticoccidial drugs in broilers has led to concerns, especially the drug residues in meat and the occurrence of drug resistance. This study aimed to extract, standardize, quantify and utilize mangosteen pericarp extract (MPE) containing α-mangostin as a replacement for anticoccidial drugs in broiler feed. The pericarp was acquired from different areas of Thailand and used for extraction and standardization. The antioxidant activity of the extract was evaluated. The extract was formulated into granules, and the flowability and stability of the granules were assessed. The MPE formulation was added to the broiler feed and then fed to the broilers that were infected with Eimeria tenella. The growth rate and intestinal lesion score (post-mortem) of the broilers were assessed. The pericarp obtained passed the identification test and phytochemical analyses. The active compound, α-mangostin, was best extracted using 95% ethanol. The MPE had superior antioxidant activity compared to standard antioxidants. Granules of the extract formulated with Avicel® PH102 provided desirable flowability and stability. The broilers fed with the feed containing 500 mg/kg α-mangostin showed a similar growth rate and post-mortem lesion score compared with the control group and those that received feed containing 60 mg/kg salinomycin. Our findings demonstrated that MPE with a high content of the active compound could be developed and used in place of anticoccidial drugs in the broiler feed.

Fluoride Concentration in Tap Water from Different Regions in Thailand

Fluoride supplementation in drinking tap water is one of the well-known effective methods for dental caries prevention. However, overexposure to fluoride following excessive fluoride intake from drinking water leads to dental fluorosis. Therefore, the assessment of daily fluoride consumption is required to calculate the optimal fluoride intake. The present study investigated the fluoride concentration in tap water collected from different areas in Thailand. A total of 27 locations were selected. Three samples of tap water (500 mL each) were independently collected from one location. Each sample in the same location was collected from the same faucet of tap water and stored in different containers. The samples were collected by dental students or dentists who worked in the selected areas from March 2020 to June 2020. Briefly, the faucet was cleaned with the tap water and the water was run from the faucet for 1-2 mins. Then, water was collected in 500 mL bottles and immediately capped. Samples were then stored at room temperature in tightly sealed bottles until analysis. Findings showed that most samples contained fluoride at a concentration lower than 0.7 mg/mL. Further, the water pH was in the range of 6.81-8.37. These levels were lower than the cut-offs established by the World Health Organization (WHO) for maximum levels of fluoride and pH in drinking water. In conclusion, the present study demonstrated that fluoride levels in tap water from different regions in Thailand are lower than those recommended by WHO for fluoride levels in drinking water.

Genetic characterization of chikungunya virus isolates from Aedes aegypti mosquitoes collected during a recent outbreak in Bangkok, Thailand.

Chikungunya virus (CHIKV) is a mosquito-borne emerging pathogen that is transmitted to humans through the bite of female Aedes mosquitoes. CHIKV infection has become a major public health concern worldwide, as it has a significant impact on the healthcare system. Since 2004, the virus has emerged in Africa and subsequently spread to countries located near the Indian Ocean, including India, and to Europe, the Americas, and Asia. In Thailand, a large CHIKV outbreak occurred during 2008-2009 and was caused by a virus originating from the east/central/south African (ECSA) CHIKV genotype. Since then, the ECSA genotype of CHIKV has continued to circulate and has caused sporadic cases in different areas in Thailand. Approximately 20,000 reported cases have been confirmed by the Bureau of Epidemiology, Ministry of Public Health, Thailand, from January 1, 2018 to July 31, 2020. However, the causes of this CHIKV re-emergence remain unclear. To obtain a better understanding of CHIKV circulation during the recent outbreak in Bangkok, Thailand, complete genome analysis of CHIKV isolates from field-caught mosquitoes collected in outbreak areas was performed. A total of 28 Ae. aegypti samples (21 females and 7 males) were collected, and individual mosquitoes were used for CHIKV detection and isolation. Eleven of 28 (39.29%) female and three of 28 (10.71%) male mosquitoes were positive for CHIKV by E1 nested RT-PCR. Four CHIKV isolates were successfully isolated from four female Ae. aegypti mosquitoes. Based on complete genome analysis, several amino acid substitutions were identified in the protein coding region. The E1:K211E and E2:V264A mutations in the background of the E1:226A mutation were observed in all four CHIKV isolates. An important observation was the presence of one amino acid substitution, leading to an E1:K245R change. This mutation was found in all four CHIKV isolates from mosquitoes in this study and in Thai patients described previously. Additionally, phylogenetic analysis indicated that the four CHIKV isolates belonged to the Indian Ocean clade of the ECSA genotype. The results obtained in this study provide detailed information on the molecular characteristics and evolution of currently circulating CHIKV strains in Thailand, which are useful for developing prevention and control strategies.

Growth charts for Thai children with Prader-Willi syndrome aged 0\u201318\u2009years

BackgroundPrader-Willi syndrome (PWS) is a multisystem genetic disorder, which has a typical eating behavior and growth pattern. In the infancy period, children with PWS have low body weight followed by hyperphagia in later childhood. Disease-specific growth charts have been recommended for monitoring PWS patients. Previous literature demonstrated growth differences among individuals with PWS of different ethnicity.MethodsA retrospective multicenter study was performed in PWS patients from different areas of Thailand included collaboration with the Thai PWS support group during 2000–2017. Baseline characteristics and anthropometric data were reviewed. Both growth hormone and non-growth hormone received patients were included, but the data after receiving GH were excluded before curve construction. Growth charts for Thai PWS compared to the 50th normative centile were constructed using Generalized Least Squares (GLS) methods. Curve smoothing was performed by Fractional Polynomials and Exponential Transformation.ResultOne hundred and thirteen patients with genetically confirmed PWS (55 males and 58 females) were enrolled. Fifty percent of patients were diagnosed less than 6 months of age. We developed growth charts for non-growth hormone treated Thai children with PWS aged between 0 and 18 years. A growth pattern was similar to other ethnicities while there were some differences. Mean birth weight of PWS patients was less than that of typical newborns. Mean adult height at 18 years of age in Thai children with PWS was lower than that in American children, but taller than Japanese. Mean weight of Thai PWS males at 18 years of age was more than those from other countries.ConclusionThis study is the first to document PWS-specific growth charts in Southeast Asian population. These growth charts will be useful in improving the quality of patient care and in evaluating the impact of growth hormone treatment in the future.

Diversity of Colletotrichum spp. isolated from chili pepper fruit exhibiting symptoms of anthracnose in Thailand

Colletotrichum spp. are causal agents of anthracnose disease in chili fruits and other tropical crops. The disease is increasing in chili fruits in Thailand and significantly reduces fruit quality and fruit production. Forty-eight isolates of Colletotrichum spp. associated with chili anthracnose were collected from different areas of Thailand during 2010–2015. Based on morphological characteristic identification, 10 isolates were shown to belong to the C. gloeosporioides species complex, 24 isolates belong to the C. acutatum species complex and 14 isolates to C. capsici. For molecular identification, two primer sets, ITS1/ITS4 and ACT528/ACT738, were used for amplification of the internal transcribed spacer of rRNA gene (ITS1–5.8S–ITS2) and partial region actin gene (ACT), respectively. The phylogenetic analysis of individual and combined ITS region and actin nucleotide sequences identified the collected isolates into 4 species: C. gloeosporioides, C. siamense, C. acutatum and C. capsici. The pathogenicity test demonstrated that all four species were pathogenic on intact unwounded and healthy fruits. These results indicated that C. capsici, C. acutatum, C. gloeosporioides and C. siamense were the causal agents of chili anthracnose disease.

Molecular serotyping, virulence gene profiling and pathogenicity of Streptococcus agalactiae isolated from tilapia farms in Thailand by multiplex PCR.

This study aimed to biotype Streptococcus agalactiae isolated from tilapia farms in Thailand based on molecular biotyping methods and to determine the correlation between the serotype and virulence of bacteria. In addition to a biotyping (serotyping) technique based on multiplex PCR of cps genes, in this study, we developed multiplex PCR typing of Group B streptococcus (GBS) virulence genes to examine three clusters of virulence genes and their correlation with the pathogenicity of S. agalactiae. The epidemiology of S. agalactiae in Thailand was analysed to provide bacterial genetic information towards a future rational vaccine strategy for tilapia culture systems. Streptococcus agalactiae were isolated from diseased tilapia from different areas of Thailand. A total of 124 S. agalactiae isolates were identified by phenotypic analysis and confirmed by 16S rRNA PCR. Bacterial genotyping was conducted based on (i) molecular serotyping of the capsular polysaccharide (cps) gene cluster and (ii) virulence gene profiling using multiplex PCR analysis of 14 virulence genes (lmb, scpB, pavA, cspA, spb1, cyl, bca, rib, fbsA, fbsB, cfb, hylB, bac and pbp1A/ponA). Only serotypes Ia and III were found in this study; serotype Ia lacks the lmb, scpB and spb1 genes, whereas serotype III lacks only the bac gene. Virulence tests in juvenile Nile tilapia demonstrated a correlation between the pathogenicity of the bacteria and their virulence gene profile, with serotype III showing higher virulence than serotype Ia. Epidemiological analysis showed an almost equal distribution in all regions of Thailand, except serotype III was found predominantly in the southern areas. Only two serotypes of S. agalactiae were isolated from diseased tilapia in Thailand. Serotype Ia showed fewer virulence genes and lower virulence than serotype III. Both serotypes showed a similar distribution throughout Thailand. We identified two major serotypes of S. agalactiae isolates associated with the outbreak in tilapia culture in Thailand. We developed multiplex PCR assays for 14 virulence genes, which may be used to predict the pathogenicity of the isolates and track future infections. Multiplex PCR typing of the GBS virulence genes was developed and might be further used to predict the pathogenicity of S. agalactiae.

Application of Tamarind Gum Thickener for Polyester Disperse Printing

Tamarind gums from different areas in Thailand (Uthaithani, Ang Thong, and Nakhon Sawan) as a thickening agent were used for printing on polyester fabric with disperse dye in comparison to the commercial tamarind gum from India as presently used in textile printing. All tamarind gum samples presented high polysaccharide and protein contents. The obtained results indicated that the properties as colour values, colour strength (K/S), overall fastness properties, handling, and sharpness of printed polyester fabric were good to very good levels. Only slight differences were observed between our tamarind gum samples and commercial one.

Seasonal patterns of aflatoxin M1 contamination in commercial pasteurised milk from different areas in Thailand

Aflatoxin M1 (AFM1) levels were determined in pasteurised milk from five commercial trademarks produced in different areas in Thailand. One hundred and twenty milk samples were collected from local markets in Chiang Mai province, Thailand, to evaluate AFM1 concentrations using immunoaffinity columns and high-performance liquid chromatography with fluorescence detection. The overall median AFM1 level was 0.023 µg L−1 ranging from 0.004 to 0.293 µg L−1. All trademarks had average AFM1 concentrations lower than 0.05 µg L−1, with those in Trademarks 3 to 5 being higher than Trademarks 1 and 2 (P < 0.01). All trademarks had different seasonal patterns of AFM1, even though operating in the same area. However, only Trademark 3 showed significant differences of AFM1 levels between seasons. The results suggested that farm management factors, rather than environment factors, were likely to be the main cause of AFM1 contamination in dairy products.

Performance of an earth wall stabilized with bearing reinforcements

This article presents the performance of a fully instrumented test wall reinforced with bearing reinforcement. Bearing reinforcement is an inextensible earth reinforcement. It is composed of a longitudinal member and transverse members. The longitudinal member is a deformed steel bar and the transverse members are a set of equal steel angles. The test wall was 6 m high, 9 m long at the top, 6 m wide at the top, and 12 m long, 21 m wide at the base and was constructed on a hard stratum. The facing panels were made of segmental concrete block which measured 1.50 × 1.50 × 0.14 m in dimension. From the full-scale test results, the bearing stress distribution is a trapezoid shape as generally assumed for the examination of the external stability of MSE walls. The tilt of the bearing reinforcement earth (BRE) wall indicates that the BRE wall behaves as a rigid body. The coefficients of earth pressure decrease with depth and approach the active state at deeper reinforcement level. From the variation in the stiffness factor as a function of depth and lateral earth pressure, the bearing reinforcement has a stiffness factor of K/ K a = 1.7, which is much lower than that of steel grids and metal strips. The lower tension (coefficient of lateral earth pressure) reduces the cross-sectional area of the longitudinal members and hence cost effectiveness. The maximum tension line (possible failure plane) of the BRE wall is bilinear, similarly to the coherent gravity structure hypothesis, which is commonly used for the analysis of inextensible reinforcements. Finally, the suggested method of designing the BRE wall is presented. It has been successfully used to design several BRE walls founded on the hard stratum in different areas in Thailand.

An integrated bioinformatics approach to the characterization of influenza A/H5N1 viral sequences by microarray data: Implication for monitoring H5N1 emerging strains and designing appropriate influenza vaccines

In order to characterize A/H5N1 viral sequences, a bioinformatics approach accurately identified viral sequences from discovery of a sequence signature, which provided enough distinctive information for sequence identification. Eight highly pathogenic H5N1 viral isolations were collected from different areas of Thailand between 2003 and 2006, and were used for analysis of H5N1 genotypic testing with a semiconductor-based oligonucleotide microarray. All H5N1 samples and H1N1, H4N8 negative controls were correctly subtyped. Sensitivity of the eight oligonucleotide probes, with optimized cut-offs, ranged from 70% (95% CI 65–75) to 87% (95% CI 84–91), and the corresponding Kappa values ranged from 0.76 (95% CI 0.72–0.80) to 0.86 (95% CI 0.83–0.89). Semi-conductor-based oligonucleotide array and oligonucleotide probes corresponded well when detecting H5N1. After fully correcting the subtype from the result of microarray signal intensity, the microarray output method combined with bioinformatics tools, identified and monitored genetic variations of H5N1. Capability of distinguishing different strains of H5N1 from Thailand was the outstanding feature of this assay. Ninety percent of HA and NA (4/5) genes were sequenced correctly, in accordance with previous examinations performed by classical diagnostic methods. The low-medium-high bioinformatics resolutions were able to predict an epidemic strain of H5N1. This study also showed the advantage of using a large genotypic database to predict the epidemic strain of H5N1. However, the monitoring protocol of this new strain has been recommended for further study with a large-scale sample.

Presence of multiple viruses in non-diseased, cultivated shrimp at harvest

Histological examinations were carried out with 400 cultivated black tiger shrimp ( Penaeus monodon) from 12 commercial rearing ponds from three different areas in Thailand over a period of 3 years. The shrimp were collected at or near harvest time as two arbitrary size groups of 10–20 each from each pond. Aside from size difference, they showed no gross signs of disease and were normally active. Pathognomonic histopathological lesions were found only for hepatopancreatic parvovirus (HPV) or monodon baculovirus (MBV). Although these were relatively frequent, no unusual shrimp mortality had occurred in any of the ponds examined. Severity of these infections was negatively correlated with shrimp size. When grouped together, HPV-infected shrimp gave mean lengths of approximately 6.5 cm that were significantly different from uninfected shrimp at 9 cm length, early in the cultivation cycle while MBV-infected groups of approximately 9 cm length were not readily distinguishable until uninfected shrimp were 10 cm or more, later in cultivation. Thus, HPV infection was correlated with more severe stunting than MBV. In addition to histopathological examination, polymerase chain reaction (PCR) assays for HPV, white spot syndrome virus (WSSV) and infectious hypodermal and hematopoietic necrosis virus (IHHNV) were carried out on one large sample of 240 shrimp from 6 ponds where visible lesions were apparent for MBV only. Surprisingly, 94% of the specimens gave a positive test for at least one of the four viruses. HPV and IHHNV alone or in combination were detected at high prevalence (approximately 60%) despite the absence of visible histological lesions and were confirmed by southern blot hybridization. Although the prevalence of the four viral pathogens was very high, it would normally have gone unnoticed, since normal shrimp are rarely examined for viruses.

Karyotypes Among Various Morphological Populations of Hill Mynah, Gracula religiosa, from Different Areas in Thailand

Karyotypes Among Various Morphological Populations of Hill Mynah, Gracula religiosa, from Different Areas in Thailand

Water Quality in Laboratory Soil‐Water Microcosms with Soils from Different Areas of Thailand

AbstractForty‐five soil samples were collected from aquaculture areas in 23 provinces of Thailand to include six soil orders and wide variation in physical and chemical properties. Soil‐water microcosms were prepared containing 5 g of soil and 150 mL of distilled water. Microcosms were held on an oscillating table shaker (150 rpm) for 1 wk at 25 C in the dark. Water pH and concentrations of dissolved nutrients, total alkalinity, and total hardness were measured. Differences in properties within soil orders caused wide variation in composition of solutions and differences in concentrations of dissolved substances and pH were not related to soil order. Regression analyses revealed significant correlations between concentrations of soil nutrients extractable in dilute acid (0.05 N HCI plus O.025 N H2SO4) or in neutral, 1 N ammonium acetate and aqueous concentrations. Regression coefficients usually were higher for dilute‐acid extractable nutrients than for ammonium acetate extractable ones. Regression coeficients based on dilute‐acid extractable nutrients follow: soluble reactive phosphorus (r= 0.816); calcium (r= 0.685); magnesium (r= 0.470); potassium (r= 0.959); sodium (r= 0.977); manganese (r= 0.462); boron (r= 0.399). The correlation between soil and solution iron was not significant and aqueous concentrations of copper and zinc were below detection limit. Hardness was correlated with soil carbon (r= 0.710) and soil pH was a good predictor of alkalinity (r= 0.877). Soil pH and aqueous pH were highly correlated (r = 0.939). Findings suggest that soil characteristics can be used to predict pH and concentrations of several dissolved substances in soil‐water systems under aerobic conditions.

The role of infection by Opisthorchis viverrini, hepatitis B virus, and aflatoxin exposure in the etiology of liver cancer in Thailand. A correlation study.

The incidence of the two principle types of liver cancer (hepatocellular carcinoma and cholangiocarcinoma) in five different areas of Thailand was compared with the prevalence of exposure to the main risk factors in samples of the population. Cholangiocarcinoma showed striking variations in incidence, which correlated closely with markers of exposure to the liver fluke, Opisthorchis viverrini. However, there was little geographic variation in incidence of hepatocellular carcinoma or in prevalence of the major risk factors (chronic carriage of hepatitis B virus and exposure to aflatoxin), and apparently there was little relationship between them.