Job's Tears Research Articles

Exposure to aflatoxins in Japan: risk assessment for aflatoxin B1

The intake of total aflatoxins (AFT) and aflatoxin B1 (AFB1) from food in Japan was estimated from AFT and AFB1 concentration and frequency data in 24 foods (884 samples) from a 3-year retail market survey from the summer of 2004 to the winter of 2006, and by food consumption data from the National Health and Nutrition Survey performed in 2005. The AFT and AFB1 survey revealed that peanut, peanut products, cocoa, chocolate, pistachio, white pepper, red pepper, almond, job's tears, buckwheat and corn grits are considered to be contributors of AFT (or AFB1) intake in Japan (maximum AFB1 (AFT) levels ranged from 0.21 to 28.0 µg kg−1 (from 0.21 to 9.0 µg kg−1)) in AFT-contaminated food. A probabilistic approach using the Monte Carlo method was carried out to simulate an estimate of the AFT (or AFB1) intake distributions in each age group in Japan. In this study, AFB1 intake ranged from 0.003 to 0.004 ng kg−1 body weight day−1 (from lower to upper limits), and the potential risk for cancer using a formula devised by the Joint Food and Agricultural Organization/World Health Organization (FAO/WHO) Expert Committee on Food Additives (JECFA) was estimated at 0.00004–0.00005 person/year/100,000 persons, even though this was in the higher levels (95.0th percentile) of the consumer population. The results suggest that the current dietary intake of AFB1 in Japan has no appreciable effect on health.

Effects of Cheonggukjang Added with Job's Tears Diet on Anticoagulation Activity and Serum Lipid Profile in Hyperlipidemic Rats

The effects of Cheonggukjang (Korean traditional fermented soybean soup) and Cheonggukjang added with Job's tears were investigated on anticoagulation activities and lipid metabolism in adult male rats fed on high fat diet for 4 weeks. Five treatment groups(n=12 each) were the high fat control group(A) fed on AIN‐93G added with lard(5%) and cholesterol (0.5%), high fat control diet added with 9%(B), 18%(C), 27%(D) and 36%(E) of Job's tears, respectively. There were no significant changes in body weight gain and body fat amount, but food intake was significantly lower in Job's tears added groups than that of the control(p<0.05). In terms of anticoagulation activities, bleeding time was not different, but activated partial thromboplastin time and prothrombin time were siginificantly different(p<0.05). Serum total‐cholesterol and free cholesterol, and phospholipid levels in Job's tears added diet groups were lower(p<0.05). HDL‐cholesterol level was the lowest in group E(p<0.05), but triglyceride and LDL‐ cholesterol levels did not differ among the groups. Atherogenic index tended to be lower in Job's tears added groups except for group E. From the findings, cheonggukjang diet added with Job's tears seemed to be effective in improving blood lipid profile and anticoagulant activity.

Prevalence, genetic diversity, and antibiotic susceptibility of Bacillus cereus strains isolated from rice and cereals collected in Korea.

Incidence and properties of Bacillus cereus strains naturally present in cereals were evaluated by phenotypic characterization, antibiotic susceptibility testing, and pulsed-field gel electrophoresis. Of 293 cereal samples tested, 73 (25%) contained B. cereus strains. Incidence of B. cereus isolates varied with respect to sample; they were found in 15 (37%) of 83 brown rice samples, 23 (37%) of 63 glutinous rice samples, 16 (21%) of 76 barley samples, and 19 (27%) of 71 Job's tears samples. All B. cereus isolates from cereals were positive for diarrheal toxin genes. The isolates were susceptible to most of the antibiotics tested, but they were highly resistant to ampicillin, cefepime, oxacillin, and penicillin. Of the genes assayed by the PCR technique, a high frequency of nheA (99%) and hblDC (84%) was found in the genomic DNA of cereal-associated isolates, whereas cytK was less common (55%). From the strains carrying the hblDC genes, 93% produced enterotoxin HBL. B. cereus isolates did not have significant genetic homology. The genetic diversity and toxic potential differ among the strains isolated from cereals. These results provide important information on toxin gene profiles of cereal-associated B. cereus for population studies.

Growth response and tolerance of Job's tears (Coix lacryma-jobi L) to arsenic in spiked soils

Job's tears (Coix lacryma-jobi L.), a perennial herbaceous plant, was cultured in soils spiked by arsenic. The results show that Job's tears rapidly grows with high biomass and strongly tolerates with normal accumulation for As in lightly or moderately spiked soils. It insensitively responds to As changes when the content of As in soils is less than 40 mg kg−1 while the concentration of As in tissues significantly increases and most of it accumulates in roots when the concentration of As in soils is more than 80 mg kg−1. Job's tears is helpful to eco-remediate lightly or moderately As-contaminated soils.

Assessment of tillage erosion rates on steep slopes in northern Laos

In the hills of south-east Asia shifting cultivation is developing towards more permanent cropping systems. In association with short fallow periods, fields suffer from weed pressure and this, in turn, leads to more frequent and deeper manual tillage. Due to steep slopes these operations induce tillage erosion. Measurements of such soil losses under on-farm conditions are still scarce. In this study tillage erosion was assessed and a predictive model of tillage erosion was established based on slope angle and contact cover, i.e. basal crop area and weed cover. The experiments were conducted in the Houay Pano, Northern Laos. The farmers cultivate annual crops in rotation with 1–3 year fallow periods without external inputs and using only hand tools. Tillage erosion was assessed using the tracer method across nine slope classes (0.30–1.10 m m −1) for two crops, upland rice and Job's tears ( Coix lacryma-jobi L.). Soil movement due to land preparation and weeding were assessed separately because different tools are used, a medium size hoe and a small curved hoe. A multivariate regression showed a highly significant relation ( R 2 = 0.83) between soil losses due to land preparation, slope gradient and contact cover. Predicting models of soil losses due to weeding were also highly significant ( R 2 = 0.79 for upland rice, R 2 = 0.88 for Job's tears), confirming the importance of tillage erosion on steep slopes (4, 6 and 11 t ha −1 year −1 on slopes with gradients of 0.30, 0.60 and 0.90 m m −1, respectively). Tillage erosion has increased exponentially over the last 40 years because of weed invasion associated with short fallow periods; the initially no-till system has changed into a system heavily dependent on tillage to control weeds and this greatly contributes to soil degradation.

Chemical, Molecular, and Structural Characterization of Alkali Extractable Nonstarch Polysaccharides from Job’s Tears

The polished Job's tears ( Coix lachryma-jobi L.) seeds, dark and white husk types, were sequentially extracted by hot water (75 degrees C) and 0.5 M NaOH solution. Nonstarch polysaccharides were not found in the water extract but were present in the alkali extract. The major components of the alkali extract from both Job's tears were protein, ash, and nonstarch polysaccharides, mainly arabinoxylans. The high arabinose to xylose ratio of 1.25 and 1.24 indicated a highly substituted structure. The average molecular weight (MW) of arabinoxylans of the dark and white husk types were 741,000 Da (Pd 1.5) and 1,449,000 Da (Pd 2.6), respectively, and their average MW reduced after treatment with protease. The alkali extractable arabinoxylans were elucidated to have a (1,4)-linked beta- d-xylan main chain highly substituted with single arabinose units. The results showed that the alpha- l-arabinofuranosyl residues (Ara f) were attached to the main chain mostly at O-3, followed by both O-2 and O-3 of xylopyranosyl residues (Xyl p).

Runoff and sediment losses from 27 upland catchments in Southeast Asia: Impact of rapid land use changes and conservation practices

Rapid changes in upland farming systems in Southeast Asia generated predominantly by increased population pressure and ‘market forces’ have resulted in widespread land degradation that has been well documented at the plot scale. Yet, the links between agricultural activities in the uplands and downstream off-site effects remain largely unknown because of the difficulties in transferring results from plots to a larger scale. Many authors have thus pointed out the need for long-term catchment studies. The objective of this paper is to summarize the results obtained by the Management of Soil Erosion Consortium (MSEC) over the last 5 years from 27 catchments in five countries (Indonesia, Laos, Philippines, Thailand, and Vietnam). The purpose of the study was to assess the impacts of cultivation practices on annual runoff and erosion rates. Initial surveys in each catchment included topography, soils and land use. Monitoring included climatic, hydrologic and erosion (total sediment yield including bed load and suspended sediment load) data, land use and crop yields, and farmers’ income. In addition, new land management options were introduced through consultations with farmers and evaluated in terms of runoff and erosion. These included tree plantations, fruit trees, improved fallow with legumes, maize intercropped with legumes, planted fodder, native grass strips and agro-ecological practices (direct sowing and mulch-based conservation agriculture). Regressions analyses showed that runoff during the rainy season, and normalized runoff flow coefficient based on erosive rainfall during the rainy season (rainfall with intensity exceeding 25 mm h −1) increase with the percentage of the catchment covered by maize. Both variables decrease with increasing soil depth, standard deviation of catchment slope (that reflects terrain roughness), and the percentages of the catchment covered by fallow (regular and improved), tree plantations and planted fodder. The best predictors of sediment yield were the surface percentages of maize, Job's tears, cassava and footpaths. The main conclusions generated from this study were: (i) soil erosion is predominantly influenced by land use rather than environmental characteristics not only at the plot scale but also at the catchment scale; (ii) slash-and-burn shifting cultivation with sufficiently long rotations (1 year of cultivation, 8 years of fallow) is too often unjustly blamed for degradation; (iii) in its place, continuous cropping of maize and cassava promotes high rates of soil erosion at the catchment scale; (iv) conservation technologies are efficient in reducing runoff and total sediment yield at the catchment scale; (v) the adoption of improved soil management technologies by upland farmers is not a function of the degree of intensification of their farming system and/or of their incomes. The results suggest that if expansion of maize and cassava into already degraded upland systems were to occur due to increased demand for biofuels, there is a risk of higher runoff and sediment generation. A failure to adopt appropriate land use management strategies will result in further rapid resource degradation with negative impacts to downstream communities.

A consideration of the involucre remains of Coix lacryma-jobi L. (Poaceae) in the Sampula Cemetery (2000 years BP), Xinjiang, China

Three clusters of necklaces made of involucres of Job's tears and glazed beads were found in the Sampula Cemetery (nearly 2000 years old) of Xinjiang, northwest China. A package of fruits including Panicum miliaceum, Hordeum vulgare var. nudum, and involucres of Job's tears have also been unearthed from the same cemetery. These are the most convincing evidence of Job's tears used as beads in earlier times. Moreover, the necklaces made of Job's tears are considered to have a connection with the Buddhist culture. There is also the possibility that plants of Job's tears have been cultivated and utilized by the indigenous people due to their commercial or religious importance.

The Origin of Flooded Rice Cultivation

Rice cultivation has long been considered to have originated from seeding of annual types of wild rice somewhere in subtropics, tropics or in the Yangtze River basin. That idea, however, contains a fatally weak point, when we consider the tremendous difficulty for primitive human to seed any cereal crop in the warm and humid climate, where weed thrives all year round. Instead of the accepted theory, we have to see a reality that vegetative propagation of edible plants is a dominant form of agriculture in such regions. The possibility is discussed that Job's tears and rice, two cereal crops unique to the region, might have been developed via vegetative propagation to obtain materials for medicine or herb tea in backyard gardens prior to cereal production. This idea is supported by the fact that rice in temperate regions is still perennial in its growth habit and that such backyard gardens with transplanted taro can still be seen from Yunnan Province of China to Laos. Thanks to detailed survey of wild rice throughout China for 1970–1980, it is now confirmed that a set of clones of wild rice exist in shallow swamps in Jiangxi Province, an area with severe winter cold. In early summer ancient farmers may have divided the sprouting buds and spread them by transplanting into flooded shallow marsh. Such way of propagation might have faster improved less productive rice through a better genetic potential for response to human interference than quick fixation in seed propagation, because vegetative parts are heterogeneous. Obviously, such a primitive manner of rice cultivation did include the essential parts of rice farming, i.e., nursery bed, transplanting in flooded field of shallow marsh like. Transfer from the primitive nursery to true nursery by seed may have later allowed rice cultivation to be extended to northern regions. In thus devised flooded cultivation there were a series of unique advantages, i.e.; continuous cropping of rice in a same plot, no soil erosion, slow decline of soil fertility, availability of minerals, and resulting in high yield per unit area, which have collectively attained the highly productive cereal cultivation in the warm and humid region. Rice cultivation in marsh is also favorable to raise fish culture, both of which constituted a nutritionally balanced base. Development of irrigation technology to construct flooded farms gave strong bases for stable rice-cultivating society, which in the end formulated the rise of ancient kingdoms of Yue and Wu in China in BC 6 th -5 th centuries. They were direct descendents of those people who had developed the unique rice cultivation from the era of Hemudu culture, which is dated back to 5 000 BC. Their movement to the south is considered to have established rice-cultivating communities in South China and Southeast Asia, while to the north it transferred the rice-based technology to ancient Korea and Japan and had established there a base for a civilized society.

Newly developed polymorphic microsatellite markers in Job's tears (Coix lacryma‐jobi L.)

AbstractA microsatellite‐enriched library of Job's tears (Coix lacryma‐jobi L. var. Ma‐yuen Stapf) was constructed using a modified biotin–streptavidin capture method. After screening, 17 polymorphic microsatellites were used for diversity analysis among 30 Job's tears accessions. The number of alleles ranged from one to five alleles per locus with an average of 2.8 alleles. Expected heterozygosity (HE) and polymorphism information content (PIC) ranged from 0 to 0.676 and from 0 to 0.666, respectively. The newly developed microsatellite markers are expected to be very valuable tools for evaluation of genetic diversity among large germplasm collection of Job's tears present in our Korean Gene Bank.

Speculations on the Importance of Job's Tears in Past Agricultural Systems of Bhutan

Speculations on the Importance of Job's Tears in Past Agricultural Systems of Bhutan

Farmers' knowledge of soils in relation to cropping practices: A case study of farmers in upland rice based slash-and-burn systems of northern Laos

Understanding indigenous knowledge of soils has come to be seen as essential in understanding the local realities of farmer and may be critical for the success or failure of agricultural development. However, little effort has been made to capture the indigenous knowledge of upland farmers in northern Laos where many projects are working to develop sustainable crop production systems as alternatives to slash-and-burn systems. This paper discusses the indigenous knowledge of Loum and Khamu slash-and-burn farmers in relation to soil quality and cropping practices. Most farmers interviewed distinguished two or more soils in their field. When farmers were asked to describe their soils, farmers took a holistic view and not only discussed the soil (primarily color or texture) but also the occurrence of weeds on the soil and the quality of burn. Glutinous rice, their staple food, tended to be planted on good soils, while non-glutinous rice and cash crops (i.e. Job's tears and sesame) were planted on poor soils. Farmers' classification of soils showed good correlation with soil chemical and physical analysis and agronomic performance. For example, color was the most common descriptor of soils. Black soils, which farmers ranked highest in preference, had higher pH, total N, total C and CEC levels than the other color soils. Also, upland rice yields were significantly higher on black soils compared to other soils. Such information can facilitate collaboration between farmers, extension workers and researchers to improve crop production systems and the use of soil and natural resources.

EFFECTS OF HERBAL EXTRACTS ON THE FUNCTION OF HUMAN ORGANIC ANION-TRANSPORTING POLYPEPTIDE OATP-B

Most known interactions between herbal extracts and drugs involve the inhibition of drug-metabolizing enzymes, but little is yet known about the possible role of transporters in these interactions. In this study, we have examined the effects of herbal extracts used in dietary supplements on the function of organic anion-transporting polypeptide B (OATP-B; OATP2B1), which is expressed on human intestinal epithelial cells and is considered to be involved in the intestinal absorption of various drugs. Specifically, the effects of 15 herbal extracts on uptake of estrone-3-sulfate, a typical OATP-B substrate, by human embryonic kidney 293 cells stably expressing OATP-B were evaluated. At concentration levels considered likely to be attainable in the human intestine, extracts of bilberry, echinacea, green tea, banaba, grape seed, ginkgo, and soybean potently inhibited estrone-3-sulfate uptake by 75.5, 55.5, 82.1, 61.1, 64.5, 85.4, and 66.8%, respectively (P < 0.01). The inhibitory effect of ginkgo leaf extract was concentration-dependent (IC(50) = 11.2 +/- 3.3 microg/ml) and reversible. Moreover, flavonol glycosides and catechins significantly inhibited the function of OATP-B, suggesting that the inhibitory effects of the herbal extracts on OATP-B may be primarily attributable to flavonoids. The extracts of mulberry, black cohosh, and Siberian ginseng moderately (but significantly) inhibited estrone-3-sulfate uptake by 39.1, 47.2, and 49.2%, respectively (P < 0.05). Extracts of barley, Job's tears, rutin, rafuma, and passionflower were ineffective. These results suggest that coadministration of some dietary supplements may decrease the absorption of orally administered substrates of OATP-B.

Chinese Food and Cancer Healing

In cancer treatment, apart from studying the effectiveness of chemo or radiotherapy in killing cancer cells, studies should examine ways of reducing drug side effects on patients and ways of enhancing the bodies’ immune system at the same time. Our defence system not only includes immune response, there are also detoxifying enzymes, anti-oxidant mechanisms, the ability for DNA damage repair and regulation of the hormone metabolism. Harmful environmental oestrogens that enter the human body can cause an increase of 16-α-hydroxyestrone as a harmful estradiol metabolite, the ratio between 16-α-hydroxyestrone and 2-hydroxyestrone relates to the risk of breast cancer. It is suggested that choosing nutritional products (that decrease the amount of 16-α-hydroxyestrone to regulate the hormone metabolism) can help with prevention of breast cancer. Increasing the ratio of monounsaturated fatty acid omega-3 (Ω-3) benefits health. Unsaturated fatty acid omega-6 (Ω-6) appears to be easily oxidised which can lead to DNA damage and increase the occurrence of cancer. The most important aspect to this approach is to reduce the ratio between saturated fatty acid and polyunsaturated fatty acid Ω-6, which is harmful to health. Olive oil has a high content of Ω-3 that benefits health. Ω-3 fatty acid can also be obtained from some fish, green vegetables and nuts. Linoleic acid is the most important source of Ω-6 fatty acid. Linolenic acid is the most important source of Ω-3 fatty acid. Natural foods e.g., purslane, is rich in Ω-3; the mustard family vegetables can increase the activity of detoxifying enzymes. Chinese Kiwi fruit drink reduces the side effects of the chemotherapy drug cyclophosphamide, which is also a DNA damaging agent. Soybean, job's tears, garlic, mushroom varieties and tea have anti-cancer effects. Properly used nutritional products may assist treatment and recovery. Good balanced nutrition is essential for cancer healing.

형태적 특성에 의한 벼과작물 종자전염 Penicillium spp.의 동정

1997년부터 2003년에 걸쳐 우리나라에서 수확된 보리, 율무, 옥수수, 수수, 벼에서 총 81개의 Penicillium 속균을 분리하였다. 분리된 Penicillium 속균의 배양적 형태적 특징을 이용하여 종을 동정한 결과 P. citrinum, P. chrysogenum, P cyclopium, P. oxalicum, P. polonicum, P. purpurogenum 그리고 P. viridicatum으로 동정되었다. 이 중에서 P. cyclopium, P. polonicum, P. purpurogenum은 국내에서 처음 보고되는 미기록종들이다. A total of 81 isolates of Penicillium were isolated from postharvest seeds of barely, Job's-tears, maize, sorghum and rice from 1997 to 2003. Based on the morphological characteristics, they were identified as P. chrysogenum, P. citrinum, P. cyclopium, P. oxalicum, P. polonicum, P. purpurogenum and P. viridicatum. P. chrysogenum was detected from Job's-tears, rice and sorghum seeds, P. citrinum from maize seeds, P. cyclopium from sorghum seeds, P. oxalicum from barely, maize, sorghum and rice seeds, P. purpurgenum from maize, rice, sorghum seeds, P. viridicatum from Job's-tears, maize and rice seeds, P. polonicum from Job's-tears, maize, rice and sorghum seeds. Among these species, P. cyclopium, P. polonicum and P. purpurogenum were first reported in Korea. Especially, about 50% of the Penicillium isolates detected from the seeds were P. polonicum. Identification of the Penicillium species using morphological characteristics was difficult especially for the species belonging to the subgenus Penicillium such as P. polonicum.

Maize in Pre-Columbian China

A certain Chinese herbal book presented to the emperor in 1505 shows a drawing of maize under the caption of Yiyi-ren (Job's Tears). Also, a Chinese poem written around 1368 contains a term yumi, which indicates maize. These new findings offer clear evidence that maize existed in China in the pre-Columbian era, or before 1492. Details of this evidence are discussed here.

Neutral lipid isolated from endosperm of Job's tears inhibits the growth of pancreatic cancer cells via apoptosis, G2/M arrest, and regulation of gene expression

The neutral lipid isolated from the endosperm of Job's tears (NLEJ) has been known to possess an anticancer activity with relatively low toxicity. The present study was designed to examine its antiproliferative effects in the PaTu-8988 and SW1990 human pancreatic cancer cells and to investigate its potential mechanism(s). Pancreatic cancer cells were treated with NLEJ to evaluate cell viability, cell cycle progression, nuclear morphology, DNA fragmentation and annexin V binding analysis. Regulation of gene expression was determined by using cDNA microarrays and western immunoblotting. The NLEJ induced a dose- and time-dependent inhibition of proliferation in both PaTu-8988 and SW1990 cell lines. Further studies were carried out with only the PaTu-8988 cells. Flow cytometry analysis showed that NLEJ blocked cell cycle progression at the G(2)/M phase. There was also an increase in annexin V binding and DNA fragmentation, indicative of apoptosis. The cDNA microarray analysis with cell cycle- and apoptosis-targeted arrays showed that the expression signals of 24 genes were found to be significantly altered at 24 h of NLEJ treatment. These genes are involved in cell cycle control (e.g. p21, p27, CDK2, and cyclins), apoptosis regulation (e.g. bcl-2 and bax), and signal transduction (e.g. ATM, RAD50, and p53). Some of these results were confirmed by western blot analysis. These data show that NLEJ inhibits pancreatic cancer cell growth through induction of apoptosis and cell cycle arrest as well as regulation of gene expression in vitro. Therefore, NLEJ might be a chemotherapeutic agent against pancreatic cancer.

톱밥 및 농업부산물 이용 배지상에서 노루궁뎅이버섯(Hericium erinaceum)의 균사생장 및 자실체형성

본 실험은 다양한 농가부산물들이 노루궁데이버섯의 재배를 위한 기질로써 적합한지를 알아보기 위하여 실시되었다. 이를 위해 참나무 톱밥, 사탕수수박, 코코낫박, 율무박, 왕겨, 배추, 면자각의 기본 기질들과 미강, 옥수수박의 첨가물을 서로 다른 비율과 조성을 통하여 노루궁뎅이버섯 균주를 접종한 후, 균사생장과 균사밀도, 자실체 생산량, 생물학적 효율을 조사 비교하였다. 참나무 톱밥 80%+미강 20%의 기질이 우수한 균사생장, 균사밀도, 자실체 생산량, 생물학적 효율을 보여 종균용 기질로써 적합하였다. 이러한 기질 조성의 적합성은 병재배법을 이용하는 농가에서 3개 노루궁뎅이버섯 균주를 사용하여 행한 실증실험에서 입증되었다. 그러나 봉지재배법을 이용한 농가 실증시험에서는 면자각 40%+참나무 톱밥 40% 기질에 옥수수 및 미강을 각각 10%씩 영양원으로 첨가한 기질에서 자실체 생산 및 생물학적 효율이 우수한 것으로 나타났다. This study was carried out to investigate the suitability of various agricultural by-products as basal substrates for the mycelial growth and fruiting body formation of Hericium erinaceum. For this aim, oak sawdust, cotton waste, sugarcane bagasse, Job's tears, rice hull, Chinese cabbage, and coconut waste were used as sole or mixed substrate(s). Corn waste and rice bran were used as nutrient supplements. The growth and density of mycelium, yield of fruiting body, and biological efficiency were compared among tested substrates colonized by Hericium erinaceum. The best measurement of mycelial growth and density, yield of fruiting body, and biological efficiency in a laboratory test was found in a spawn substrate composed with oak sawdust 80% and rice bran 20%. The suitability of this spawn substrate composition for Hericium fruiting body production was testified through practical tests in plastic bottles (850 ml) in a mushroom farm which had bottle cultivation facility. However, test in a mushroom farm which had plastic bag cultivation facility, best production of Hericium fruiting body (520 g per one bag) was observed in a spawn substrate composed of cotton waste 40%, saw dust 40%, corn waste 10%, and rice bran 10%.

Determination of the Residues of Eleven Organophosphorus Insecticides in Job's-tears by Gas Chromatography with a Nitrogen-Phosphorus Detector

A simplified method for determining 11 organophosphorus insecticides (dichlorvos, methamidophos, acephate, diazinon, dimethoate, chlorpyrifos, malathion, parathion, quinalphos, methidathion, and ethion) in the Chinese herbal medicine Job's-tears is described. Standards were fortified into Job's-tears (5 g) at 4 levels. The organophosphorus insecticides were extracted with dichloromethane and cleaned up with a mixture of Celite 545-activated carbon (4 + 1). The extracts were analyzed by gas chromatography using a nitrogen-phosphorus detector. Analysis of fortified Job's-tears shows average recoveries ranged from 73.90-98.70%, 86.31-93.15%, 84.92-96.22%, and 83.29-104.23% at 0.05, 0.1, 0.5, and 1.0 mg/kg levels, respectively. The minimum detectable amount ranged from 1.0 x 10(-10) to 5.0 x 10(-10) g, and the limit of quantitation for the method was 0.05 mg/kg. The method is rapid, simple, sensitive, reproducible, and applicable to the determination of these 11 organophosphorus insecticides in Job's-tears.

Changes in Slash-and-Burn Agriculture after the Introduction of Cash Crops in the Hilly Areas of Laos

Though subsistence-oriented slash-and-burn rice production is still the major land use in the hilly areas of Northern Laos, it is now increasingly problematic, especially in areas adjacent to main roads. Due principally to increased population pressure, the period of fallow has declined and labor requirements for weeding have dramatically increased. In addition, the Lao government considers shifting cultivation to be a major cause of deforestation and has recently initiated a series of policies to restrict it. The main policy now being implemented is the 'land allocation program' which aims to stabilize shifting cultivation and to promote permanent agriculture by allocating a limited area of agricultural land to each household.On the other hand, market-oriented agricultural activities of shifting cultivators, such as cash crop cultivation, collection of forest products, animal husbandry and teak plantation forestry, are now becoming increasingly important since the Lao government adopted a policy to revitalize the market from 1986. As a result, a cash income has become very important in rural and urban areas. Among these activities, cash crop cultivation is now widely adopted in some areas of Northern Laos, influencing local land use and livelihood. This is due in part to the policy of the Lao government; the government is now promoting intensive agriculture with cash crops as an alternative to slash-and-burn rice production.The present study aims to reveal the influence of the introduction of cash crop cultivation on land use in the hilly areas of Laos, with a focus on Number 10 Village, which is located 25km to the south of Luang Prabang, the largest town in Northern Laos. The main ethnic group is the Khmu. In this village, the upland fields planted with both upland rice and cash crops (Job's tears and paper mulberry) were mapped by means of GPS to describe today's land use. Interviews were also conducted with every household to investigate the household economy and land use history of each field.The conclusions are as follows.In Number 10 Village, the land allocation program was conducted in 1996 and afterwards intensive cultivation of cash crops was promoted by the local government and international organizations as an alternative to slash-and-burn rice production. Due in part to this policy, many households have started cultivating Job's tears and paper mulberry, but it has never been an alternative to slash-and-burn rice production. Job's tears is a cereal crop which is exported to Thailand and Taiwan, and is then processed into beer, sweets and health foods. Although cultivation is usually highly profitable, households cannot rely permanently on it due to large price fluctuations. Paper mulberry is a tree crop, the inner bark of which is exported mainly to Thailand and is processed into paper. It has a rather stable price and is easy to cultivate, but is rarely cultivated intensively because of its low profitability.On the other hand, upland rice cultivation is still the most important land use practice in the village, engaging 88% of households at the scale of 1.13 ha per household. Most households continue production without observing the rules established by the land allocation program. Today, they practice it under the rotation of shorter fallow and an increased cultivation period, which has caused a very significant increase in the labor requirements for weed control. If the rotation is intensified by limiting agricultural land, it cannot be continued. Therefore, many households still continue on land where cultivation is prohibited according to the rules established by the program.Most households combine subsistence-oriented rice production and market-oriented cash crop cultivation. This combination has important merit for them in that they can mitigate the risks associated with cash crop failure or a fall in the market price due to this subsistence production.