Central Region Of Thailand Research Articles

Educational Supervisors' Metaphorical Roots of Beliefs about Teaching and Learning.

Beliefs are a complex psychological construct that have potential to drive a person to make decisions and act. A person’s metaphors can serve as roots of their beliefs. In this study, the metaphor construction task (MCT) was utilized to uncover beliefs about teaching and learning held by 216 educational supervisors from 10 provinces in the central region of Thailand. The follow-up interview was also conducted with 22 participants to further explore and validate data. The metaphors constructed by the participants were coded and categorized and then counted for frequencies and calculated for percentages. The results revealed four favorite metaphors held by the participants, that is, teacher as gardener, captain/driver, sculptor and coach. Two dominant metaphor categories were the teacher is seen as moulder/craftsperson and nurturer/cultivator. However, about one-third of the participants viewed teacher as knowledge provider or superior authoritative figure which inclined to be teacher-centered. Educational supervisors’ beliefs are metaphorically rooted and culturally influenced. The implications regarding the MCT and metaphor analysis are also discussed. Key words: Metaphor, belief, teaching and learning, educational supervisor, teacher education.

A statistical assessment of the impact of land uses on surface water quality indexes

The release of wastewater from various land uses is threatening the quality of surface water. Different land uses pose varying degrees of danger to water resources. The hazardous extent of each activity depends on the amount and characteristics of the wastewater. The concept of the contamination potential index (CPI) of an activity is introduced and applied here. The index depends on the quantity of wastewater from a single source and on various chemicals in the waste whose concentrations are above allowable standards. The CPI concept and the land use impact assessment are applied to the surface water conditions in Nakhon Nayok Province in the central region of Thailand. The land uses considered in this study are residential area, industrial zone, in-season and off-season rice farming, and swine and poultry livestock. Multiple linear regression analysis determines the impact of the CPIs of these land uses on certain water quality characteristics, i.e., total dissolved solids, electrical conductivity, phosphate, and chloride concentrations, using CPIs and previous water quality measurements. The models are further verified according to the current CPIs and measured concentrations. The results of the backward and forward modeling show that the land uses that affect water quality are off-season rice farming, raising poultry, and residential activity. They demonstrate that total dissolved solids and conductivity are reasonable parameters to apply in the land use assessment.

Screening high-risk population for hypertension and type 2 diabetes among Thais.

waist circumference (WC) and body mass index (BMI) are simple screening tools for hypertension (HT) and type 2 diabetes (DM). Cutoffs of WC for BMI for Asians have been discussed. This study aimed to assess the accuracy of screening tools and associations of WC, BMI with HT and DM. Data from the national screening programme for metabolic syndrome conducted in 2010 in 21 provinces in the central region of Thailand were analysed. A total of 10 748 participants aged >35 years were included in the analysis with cutoffs of WC set at 90 cm for men, 80 cm for women, and BMI at 23 kg/m2 for both sexes. WC produced low sensitivity and high specificity among male participants, and moderate sensitivity and specificity among female participants, while BMI produced moderate sensitivity and specificity in both sexes. Significant associations were found among those who had high WC only, high BMI only, and both high WC and BMI with HT and DM in both sexes. (males for HT, OR=1.63, 95%CI: 1.15-2.33, OR=1.22, 95%CI: 1.03-1.44 and OR=2.03, 95%CI: 1.07-2.42; males for DM, OR=1.39, 95%CI: 1.05-1.83), OR=1.77, 95%CI: 1.07-2.94 and OR= 2.05, 95%CI: 1.57-2.69, females for HT, OR=1.69: 95%CI 1.38-2.07, OR=1.32; 95%CI: 1.09-1.60 and OR=2.54, 95%CI: 2.11-2.91; females for DM, OR=1.45, 95%CI: 1.08-1.94, OR=1.45, 95%CI: 1.09-1.91 and OR=1.70, 95%CI: 1.39-2.09). When the cutoff WC was lowered among male participants to 85 cm, sensitivity increased, and significant strengths of associations with HT and DM were nearly the same. For Thailand, WC and BMI with appropriate cutoffs can be effective screening tools to recruit high-risk populations into health promotion programmes. However, WC and BMI should be implemented with other screening tools for other risk factors because of their moderate accuracy.

Identifying assessment measures and interventions reported for Thai children with cerebral palsy using the ICF-CY framework

Background: Cerebral palsy (CP) is the most common disability in childhood. The International Classification of Functioning, Disability and Health (ICF) provides a standard framework for classifying performance in people with disability, including children with CP. Linking measures actually reported with the ICF classification promotes best practice, especially pertinent in developing countries such as Thailand. This study aimed to explore the charted demographic data, assessment and intervention measures reported for children with CP in Central region of Thailand using the ICF for children and youths (ICF-CY) framework to clarify the scope of actual management practice in this population. Methods: Charts of children admitted to four public hospitals and two schools in 2007–2009 were age stratified, and approximately 48% audited (n = 269). Results: Contextual information was clearly reported, and measures could be classified across all components of the ICF, being mainly classified in Body Structures and Functions and to a lesser degree, in Activities and Participation. Our ability to compare across cultures was affected by poor recording practices limiting the amount and quality of data available. Conclusions: Classifying measures of children with CP in Thailand in terms of the ICF-CY framework demonstrates their holistic management as well as where gaps need to be addressed, and thus contributes to best practice.Implications for RehabilitationAssessments and interventions reported for children with CP in Central region, Thailand cover all components of the ICF-CY, and describe the individual roles of the Inter-professional team members.Local health practitioners should consistently conform with internationally practice by using Standardized tools assessing all components of the ICFConsistent and uniform charting practices should be used to provide accurate interpretation of actual practice, as well as a clear pathway from assessment to intervention.

Swine influenza virus infection in different age groups of pigs in farrow-to-finish farms in Thailand

BackgroundUnderstanding swine influenza virus (SIV) ecology has become more and more important from both the pig industry and public health points of views. However, the mechanism whereby SIV occurs in pig farms is not well understood. The purpose of this study was to develop a proper strategy for SIV surveillance.FindingsWe conducted longitudinal monitoring in 6 farrow-to-finish farms in the central region of Thailand from 2008 to 2009. Nasal swabs and serum samples were collected periodically from clinically healthy pigs consisting of sows, fattening pigs, weaned piglets and pigs transferred from other farms. A total of 731 nasal swabs were subjected to virus isolation and 641 serum samples were subjected to detection of SIV antibodies against H1 and H3 subtypes using the hemagglutination inhibition test and ELISA. Twelve SIVs were isolated in this study and eleven were from piglets aged 4 and 8 weeks. Phylogenetical analysis revealed that SIVs isolated from different farms shared a common ancestor. Antibodies against SIVs were detected in fattening pigs on farms with no SIV isolation in the respective periods studied. These observations suggested that piglets aged 8 weeks or younger could be a main target for SIV isolation. Farm-to-farm transmission was suggested for farms where pigs from other farms are introduced periodically. In addition, antibodies against SIVs detected in fattening pigs could be a marker for SIV infection in a farm.ConclusionsThe present study provided important information on SIV surveillance that will enable better understanding of SIV ecology in farrow-to-finish farms.

Nonimmune Hydrops Fetalis in the Stillborn

To the Editor, I read with interest the excellent article by Taweevisit and Thorner that was recently published online [1]. The article describes a series of 78 stillborn fetuses with hydrops fetalis (HF) from the Central Region of Thailand. The purposes of the study were to analyze the etiology of HF by performing autopsy investigations and to identify the various causes of nonimmune HF (NIHF) occurring in Thailand. All cases were diagnosed as NIHF. The authors established that the most common cause of NIHF in their series was homozygous alphathalassemia, compatible with the geographic origin of the series. Among other results, the authors state that 9 cases (11.5%) had no identifiable etiology and that 2 cases (2.6%) presented a phenotype indicating a chromosomal or genetic disorder. A systematic review of the etiology of NIHF was recently published [2]. All 5437 reviewed cases were categorized using 14 classification groups. Among these 14 groups, the chromosomal group comprised chromosomal abnormalities and the syndromic group included syndromes defined as clusters of structural malformations, while the idiopathic group comprised undiagnosed cases. The link between a cause and the mechanism that may trigger generalized edema of the fetus is not always clear. Although most of the 14 NIHF categories were assigned to a defined pathophysiological pathway that led to congestive heart failure, obstructed lymphatic flow, low-plasma colloid osmotic pressure, or, lastly, a combination of the above, it was not possible to reliably classify patients who had previously been assigned to the chromosomal or syndromic disorders groups. In this systematic review, the authors concluded that a definitive pathophysiological mechanism could not be identified in 33.6% of cases, including chromosomal (13.4%), syndromic (4.4%), and idiopathic (15.8%) groups. Although chromosomal or syndromic entities make up a great deal of reported causes of NIHF, I feel that these disorders are not NIHF causes per se. In an attempt to reduce the unacceptably high number of ‘‘nondiagnosed’’ (or only apparently diagnosed) cases, autopsy examination is strongly recommended. The usefulness of immunohistochemical staining techniques in the etiologic diagnosis of NIHF was recently described [3]. Seventy-nine fetuses with a diagnosis of NIHF (out of a total of 1098 fetuses) were studied using antibodies that specifically stain blood and lymph vessels (CD31, CD34, smooth muscle actin antibody, D2-40). This study demonstrated that applying a standard autopsy protocol, very similar indeed to Taweevisit and Thorner’s methods, allowed for the identification of an etiologic diagnosis in only 42 of 79 cases. Adding immunohistochemical methods and reevaluating all cases, a specific pathogenetic mechanism leading to NIHF was able to be identified in an additional 17 fetuses (59/79). The difference was statistically significant (chi-square test; P 5 0.005). This study underlined that a pathogenetic mechanism of NIHF (ie, lymph-vessel dysfunction linked to congenital dysplasia), although rarely recognized and only speculated, in fact should seriously be taken into consideration. Although immunohistochemical staining methods to detect lymphatic dysplasia are widely available, they are not usually included in the standard protocol for fetal autopsy studies. The article [3] concluded that specific immunohistochemical techniques should be mandatory in the autopsies for fetuses with NIHF.

Hydrops Fetalis in the Stillborn: A Series from the Central Region of Thailand

The purpose of this study was to analyze the cause of hydrops fetalis (HF) among fetal deaths in the central region of Thailand. Autopsy reports diagnosed as HF from 1999 to 2008 at King Chulalongkorn Memorial Hospital were retrieved, and the pathologic findings, clinical information, fetal ultrasonographic studies, and laboratory investigations were reviewed. There were 78 stillborn autopsies during this 10-year period; the mean gestational age was 28 weeks. The causes of fetal hydrops were identified in 88.5%; no cases of immune hydrops were detected. Anemia was the predominant cause of HF (n = 33; 42.2%): related to homozygous α-thalassemia (n = 17; 21.8%), twin-twin transfusion syndrome (n = 8; 10.2%), hemoglobin H (n = 3; 3.8%), lung hemorrhage (n = 1; 1.3%), adrenal hemorrhage (n = 1; 1.3%), and 3 cases of unspecified etiology (3.8%). Other causes of high-output failure included mass lesions resulting in vascular shunting (n = 2; 2.6%) and 1 case each (1.3% each) of maternal diabetes mellitus, intestinal lymphangiectasia, and Beckwith-Wiedemann syndrome. Causes resulting in low-output cardiac failure were congenital heart disease (n = 16; 20.5%) and thoracic space-occupying lesions (n = 7; 9%). The remaining causes included fetal infection (n = 5; 6.4%), congenital abnormalities suggestive of a chromosomal or genetic basis (n = 2; 2.6%), and 1 case (1.3%) of placental vascular thrombosis. Nine cases (11.5%) had no identifiable cause. Thus, the most common cause of HF in this series was homozygous α-thalassemia, reflecting the geographic location of this series.

Aflatoxin M1 Contamination in Raw Milk within the Central Region of Thailand

Aflatoxin M(1) (AFM(1)) was found in all of the 240 raw milk samples collected from milk tanks of 80 dairy farms at a collecting center in the central region of Thailand. Milk samples from individual farms were collected in three seasons. The average concentration of AFM(1) in milk samples collected in winter (0.089 +/- 0.034 microg/L) was significantly higher than those in rainy season (0.071 +/- 0.028 microg/L) and summer (0.050 +/- 0.021 microg/L). The present study suggests that regulatory limits for AFM(1) are needed to regulate and ensure the quality of raw milk and milk products in Thailand.

Monks' Health: Holistic Health Care Model by Community Participation

Problem statement: Monks’ health tended to be a continuous increased problem. They were groups who had limitations to access health services due to their monastic disciplines and their most importance for Buddhist institution. Without urgent solution, their normal way of life would have been affected. Approach: This research aimed to study current conditions and to develop monks’ holistic health care models by community participation in central region of Thailand. The study was a qualitative research conducted in 9 temples; 3 temples in urban area, 3 in semi-urban area and 3 in rural area. Samples were 224 persons; consisted of monks, public health officers from Department of Religious Affairs, local administrative organizations and people; selected by purposive sampling method. Observation form, survey form, interview form, focus group discussion and workshop were used as research tools while data was analyzed by descriptive research. Results: The result founded that in former time culture of monks’ health care was leaned on community, social, culture and tradition. People spoke in style of central Thai language and were in agricultural sector as well as had their belief in merit, sin and elder respect. Relation in communities was in form of generosity and living as similar as relatives. When some monk got sick, they would visit, take care and give foods and medicines. Most of medicines were household remedy and Thai herbal medicine that bought from drug stores in local market or grocery stores in village and monks were sent to hospital in case of severe illness. Temple was a part of community, so they had close relation. Nowadays people increasingly worked in manufactories that caused conflicts and alienations among them. Monks leaned on local markets for receiving foods offering and most of foods were cooked from flour, sugar, coconut milk and fat. These caused three-fourth of monks having chronic disease as diabetes, hypertension, high cholesterol and gout. They had behaviors on addicting to cigarette, coffee and energy drink. They had less exercise without annual health checkup. Their cells were non-hygienic with plenty of garbage, foods scrap and joss stick dust. They preferred to have medical care at private clinics than hospitals or public health centers due to long time waiting. There were some protections by local administrative organizations as pets’ vaccination and using Tempos sand granule for eliminating mosquito larva. Severe mental health problems were not found. Conclusion/Recommendations: Related agencies with monks’ holistic health care models by community participation in central region of Thailand were local administrative organizations, communities, government agencies, temples/clergies, provincial office of Buddhism and monks. Important activities were participative operations of all related sectors, monks’ annual health checkup 1-2 times a year, temples medicine cupboard, monk health care fund, pets’ vaccination, temple public health volunteer, monk exercise promotion, temple improvement with the 5-S activity and usage of temple as center for health care development.

The Developmental Model of Cultural Tourism-Homestay of the Lao Vieng and Lao Song Ethnic Groups in the Central Region of Thailand

Problem statement: Lao Wieng and Lao Songe Ethnic Groups were herded from Lanchang Region to Siam Region. In recent time, they settled down in Central Thailand. The objectives of this research were to study: (1) historical background of Lao Wieng and Lao Songe Ethnic Groups, (2) their lifestyle facilitating tourism and (3) development of cultural tourism model as Home Stay of the Ethnics. Approach: the research area included Pechaburi, Nakonpatom, Saraburi, Supanburi and Kanchanaburi Provinces. The key informants were selected by Purposive Sampling including: 30 experts, 40 practitioners and 50 general villagers. The research design was Qualitative Research. Data were collected by techniques of interview, observation and focus group discussion. They were analyzed by using Triangulation technique. The findings were presented by descriptive analysis. Results: (1) Lao Wieng and Lao Songe Ethnic Groups, were herded from Vientiene City, Lao Country abut 200 years ago. They settled down in Middle Thailand by doing rice farm. For their living, they maintained their traditional culture of community since then, (2) lifestyle facilitating tourism consisted of identity including household, relatives relationship, dressing, language, religious, custom and beliefs, (3) the model of inherited local cultural tourism as Home Stay, each ethnic group should be organized as the following model: For Lao Wieng Ethnic, the conservation and inheritance of local culture should be focused using major lifestyle factor based on household, food and dressing. For Thai Songedam Ethnic Group, major lifestyle factor should be based on lifestyle and cultural factor with identity including living place, food, dressing, tradition, ritual, local item selling and play. Conclusion/Recommendations: The ethnic group identity was necessary for cultural tourism. But, the scenery, culture, custom and tradition with identity should be emphasized so that it would be prominent by focusing on safety and congruence with the tourist’s need. Consequently, it would be blended as the adequate model in future.

A Survey of Knowledge on Diabetes in the Central Region of Thailand

The objectives of this study were to evaluate the level of knowledge of diabetes among the Thai general population, identify areas of deficiency for targeted health education effort, and identify respondent characteristics that may be associated with knowledge of diabetes. A survey involving 1000 respondents (age > or = 15 years) was conducted in the central region of Thailand. A 42-item pre-tested questionnaire to assess general and specific knowledge of diabetes (e.g., risk factors, symptoms, treatment, etc.) was administered. Scores of <50%, > or =50% to <80%, and > or =80% were classified as "poor,""fair," and "good," respectively, according to expert consensus. Mean age of respondents was 33.8 years (SD 13.4), with 57.5% being female. Mean diabetes knowledge score was fair: 25.02 of 42 (59.6%), SD 8.35 (19.9%). Respondents performed best in the risk factor section: mean (%) score was 2.88 of 4 (72%), SD 1.11 (27.8%); and worst in the section on diabetes in women: mean (%) score was 0.82 of 3 (27.3%), SD 0.96 (32.0%). In multiple linear regression analyses, education level, older age, own self having diabetes, and having a family member/relative/friend with diabetes were significantly associated with knowledge of diabetes. Knowledge of diabetes among the Thai respondents was fair. Areas of deficiency and factors associated with knowledge of diabetes were identified. Our findings would be useful in informing targeted health education programs.

Occurrence of aflatoxin M1 in pasteurized milk of the School Milk Project in Thailand.

Concentrations of aflatoxin M1 (AFM1) were determined in 150 pasteurized milk samples from the School Milk Project in Thailand. Milk samples were collected from 50 schools in the Central region of Thailand in three seasons: summer (May to June 2006), the rainy season (August to September 2006), and winter (December 2006 to January 2007). AFM1 was isolated by using an immunoaffinity column and quantified by high-performance liquid chromatography. All of the 150 pasteurized milk samples were contaminated with AFM1, and the concentrations were within the U.S. regulatory limit of 0.5 microg/liter. The highest concentration of AFM1 found in school milk samples was 0.114 microg/liter. The mean concentration of AFM1 in milk samples collected in winter was significantly higher than the mean concentrations found in the rainy season and summer. Further monitoring of school milk to evaluate the status of contamination of AFM1 is necessary, with a special emphasis on samples collected in the rainy season and winter. Thailand is one of several countries that have no regulatory limits for AFM1 in milk and milk products. The results of this study suggest that safety limits for AFM1 are needed for regulating and ensuring the quality of milk and milk products in Thailand.

Positive Serologic Test Results for Burkholderia pseudomallei in Asymptomatic Persons

1We caution against the use of a poorly validated serologic test to provide evidence of melioidosis in asymptomatic persons. The authors use the indirect fluorescent antibody (IFA) assay, which has not been used in disease-endemic countries for many years, and no validation of this assay is presented. Although we may assume that the test is broadly similar to the previous descriptions of the IFA assay, 2 the bacterial strains used (or if purified antigen was used, the nature of the antigen) are not defined. The authors cite earlier work by Ashdown and others who described a high specificity of the IFA assay, but in this report, only 11 of 89 patients had culture-confirmed melioidosis, with the remaining 78 diagnosed with subclinical melioidosis on the basis of serologic test results. 3 The clinical significance of asymptomatic persons with positive serologic results is unclear; whether such people have truly been infected and harbor latent infection is not known. Nevertheless, as the authors note, it is apparent that overt melioidosis does not develop in most of such patients. Furthermore, there may have been confounding by exposure to the antigenically similar but less virulent B. thailandensis that is present in Thailand but not in Australia. The higher prevalence of positive indirect hemagglutination (IHA) test results using B. pseudomallei antigen in Thai patients compared with those from northern Australia, with a broadly similar incidence of disease, may suggest that exposure to B. thailandensis may result in detectable antibodies against B. pseudomallei . 4,5 Studies of cross-reactivity between the IHA using B. thailandensis as the antigen in patients with cultureconfirmed melioidosis have not been consistent. 6,7 We suggest that the quantification of risk in groups exposed to mud and pooled surface water should be based on surveillance of culture-confirmed melioidosis in the population at risk. The authors do not offer any data on the incidence of melioidosis in occupationally exposed groups in the same area, such as during previous military exercises or in rice farmers. Approximately 20 cases of melioidosis per year are reported at the Chonburi Hospital approximately 80 km from the study site (with an unknown denominator), and a low rate of melioidosis has been documented in a hospital survey in the central region of Thailand compared with the northeast Issan region. 8,9 In summary, the clinical significance of seropositive asymptomatic persons in this study is doubtful, given the use of a poorly characterized serologic test, possible confounding by exposure to B. thailandensis , the lack of a non-exposed control group, and the lack of a clinical picture characteristic of melioidosis in all but one of these patients.

Record keeping, genetic selection, educational experience and farm management effects on average milk yield per cow, milk fat percentage, bacterial score and bulk tank somatic cell count of dairy farms in the Central region of Thailand

A study was conducted to estimate the record keeping, genetic selection, educational, and farm management effects on average milk yield per cow (AYC), milk fat percentage, bacterial score, and bulk tank somatic cell count (BTSCC) of dairy farms in the central region of Thailand. Farms were located in the provinces of Saraburi and Nakhon Ratchisima and were members of the Muaklek dairy cooperative. Records from individual animals were unavailable. Thus, farm records of milk yield, milk fat percentage, bacterial score, and BTCCC were collected from July 1, 2003 through June 30, 2006. Additional record keeping, genetic selection, education, and farm management information was collected through a questionnaire in May of 2006. Data from the Muaklek dairy cooperative and the questionnaire were then merged by a farm identification number. A single trait mixed model was used to analyze AYC, milk fat percentage, and BTSCC, while a log linear model was used to analyze bacterial score. Results showed that farms that kept records on individual animals had higher (P < 0.05) milk fat percentages and lower bacterial scores than farms that did not. Farms that used genetic information (EBV) and phenotypes when selecting sires were higher (P < 0.05) for milk fat percentage than farms that used only phenotypes and personal opinion. Farms milking cows with a single unit milking machine and by hand, had higher (P < 0.05) bacterial scores and BTSCC than farms using only a single or multi unit machine. Overall farms that kept individual animal records, used EBV when selecting sires, used a single method for collecting milk, and used family labor achieved higher performance from their herds than farms that did not.

Comparison of two milk pricing systems and their effect on milk price and milk revenue of dairy farms in the Central region of Thailand

A study was conducted to investigate determinates of how milk pricing system, farm location, farm size, and month and year affected farm milk price (FMP), farm milk revenue (FMR) and loss in FMR of dairy farms in the Central region of Thailand. A total of 58,575 milk price and 813,636 milk yield records from 1034 farms were collected from November of 2004 to June of 2006. Farms were located in the districts of Muaklek, Pak Chong, Wang Muang, and Kaeng Khoi. A fixed linear model was used to analyze milk price of farms. Two pricing systems were defined as 1 = base price plus additions/deductions for milk fat percentage, solids-non-fat, and bacterial score, and 2 = same as 1 plus bulk tank somatic cell count (BTSCC). Farm size (small, medium, and large) was based on the number of cows milked per day of farms. Results showed that FMP were lower (P < 0.05) in pricing system 1 than pricing system 2. Most small farms had higher (P < 0.05) milk prices than medium and large farms across both pricing systems. Large farms lost more milk revenue due to deductions from bacterial score and BTSCC than small and medium farms.

Factors affecting milk yield, milk fat, bacterial score, and bulk tank somatic cell count of dairy farms in the central region of Thailand

A study was conducted to determine the effects of season, farm location, and farm size on farm milk yield (FMY), average milk yield per cow (AYC), milk fat, bacterial score, and bulk tank somatic cell count (BTSCC) of dairy farms in the central region of Thailand. Farms were located in the districts of Kaeng Khoi, Muaklek, Pak Chong, and Wang Muang. Collection of data was at the farm level; individual animal records were unavailable. A total of 967,110 daily farm milk yield, 58,575 milk fat and bacterial score, and 24,109 BTSCC records from 1,034 farms were collected from July of 2003 to June of 2006. There were three seasons: rainy, summer and winter. Farms were categorized into small, medium, and large according to the number of cows milked per day. Results showed that FMY and AYC were higher (p<0.05) in winter and lower in the summer and rainy seasons. In addition, the majority of small size farms had higher (p<0.05) AYC and milk fat values, and lower bacterial score and BTSCC values than medium and large size farms.

Dry deposition velocity of sulfur dioxide over rice paddy in the tropical region

The SO 2 deposition velocity over a canopy of irrigated rice paddy in a tropical area was evaluated using the Bowen ratio and Fick's equations. The experimental facilities were set up in Chachoengsao province in the central region of Thailand and data was collected for a period of one year. The results showed that the deposition velocity of SO 2 varies with the time of day, and it was highest around noon time and lowest at night. Furthermore, the value for the seasonal average of V d was the highest in winter and the lowest in the rainy season. The obtained seasonal average values of V d were 0.67, 1.25, and 1.51 cm/s in the winter, summer, and rainy seasons, respectively.

The Relationship Between Smoking, BMI and Dietary Intake

To examine the relationship among smoking status (smokers, non-smokers and ex-smokers), BMI and dietary intake in adult Thais living in the central region of Thailand.

Prediction of subsurface water level change from satellite data

This study explores the potential for predicting the spatial variation in subsurface water level change with crop growth stage from satellite data in Thabua Irrigation Project, situated in the northern central region of Thailand. The relationship between subsurface water level change from pumping water to irrigate rice in the dry season and the age of the rice was analysed. The spatial model of subsurface water level change was developed from the classification using greenness or (normalized difference vegetation index NDVI) derived from Landsat 5 Thematic Mapper data. The NDVI of 52 rice fields was employed to assess its relationship to the age of the rice. It was found that NDVI and rice age have a good correlation (R2 = 0·73). The low NDVI values (−0·059 to 0·082) in these fields were related to the young rice stage (0–30 days). NDVI and subsurface water level change were also correlated in this study and found to have a high correlation (Water level change (m day−1) = 0·3442 × NDVI − 0·0372; R2 = 0·96). From this model, the water level change caused by rice at different growth stages was derived. This was used to show the spatial variation of water level change in the project during the 1998–99 dry-season cropping. This simple method of using NDVI relationships with water level change and crop growth stages proves to be useful in determining the areas prone to excessive lowering of the subsurface water level during the dry season. This could assist in the appropriate planning of the use of subsurface water resources in dry-season cropping. Copyright © 2004 John Wiley & Sons, Ltd.

Impacts of fertigation via sprinkler irrigation on nitrate leaching and corn yield in an acid–sulphate soil in Thailand

A study was conducted in an acid–sulphate soil in the central region of Thailand, in 1999, and 2000 to assess the influence of different rates of N fertigation on corn ( Zea mays L.) yield and nitrate leaching. Nitrogen source was urea and there were four N fertigation treatments which include 0 (control), 100, 150 and 200 kg N ha −1, each having three replications arranged in a randomized complete block design (RCBD). Soil was irrigated to field capacity at 50% available soil moisture depletion regime throughout the season. Leaching losses were calculated from measured daily fluxes of water percolation, soil water NO 3–N concentrations extracted by soil water sampler and from a seasonal N mass balance. The average maximum corn grain yield of 3.52 t ha −1 was obtained at 200 kg N ha −1 in 1999 and 5.42 t ha −1 was obtained at 150 kg N ha −1 in 2000. But the statistical analysis did not show any significant differences in grain yield between N200 and N150 treatments in either year. The leaching measurements showed that the highest values were obtained in N200 treatments in both years with 23 and 5.3 kg N ha −1 in 1999 and 2000, respectively. The lowest yield of 0.55 and 0.98 t ha −1 were obtained at 0 kg N ha −1 in 1999 and 2000, respectively. Also the results showed that a fertigation system can be an efficient practice and an advanced way to give water and plant nutrients together to the crop.