• Title/Summary/Keyword: Tropical Countries

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Genetic Diversity of Taenia asiatica from Thailand and Other Geographical Locations as Revealed by Cytochrome c Oxidase Subunit 1 Sequences

  • Anantaphruti, Malinee Thairungroj;Thaenkham, Urusa;Watthanakulpanich, Dorn;Phuphisut, Orawan;Maipanich, Wanna;Yoonuan, Tippayarat;Nuamtanong, Supaporn;Pubampen, Somjit;Sanguankiat, Surapol
    • Parasites, Hosts and Diseases
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    • v.51 no.1
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    • pp.55-59
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    • 2013
  • Twelve 924 bp cytochrome c oxidase subunit 1 (cox1) mitochondrial DNA sequences from Taenia asiatica isolates from Thailand were aligned and compared with multiple sequence isolates from Thailand and 6 other countries from the GenBank database. The genetic divergence of T. asiatica was also compared with Taenia saginata database sequences from 6 different countries in Asia, including Thailand, and 3 countries from other continents. The results showed that there were minor genetic variations within T. asiatica species, while high intraspecies variation was found in T. saginata. There were only 2 haplotypes and 1 polymorphic site found in T. asiatica, but 8 haplotypes and 9 polymorphic sites in T.saginata. Haplotype diversity was very low, 0.067, in T. asiatica and high, 0.700, in T. saginata. The very low genetic diversity suggested that T. asiatica may be at a risk due to the loss of potential adaptive alleles, resulting in reduced viability and decreased responses to environmental changes, which may endanger the species.

A Review of Technologies to Prolong the Shelf Life of Fresh Tropical Fruits in Southeast Asia

  • Kusumaningrum, Dewi;Lee, Seung-Hyun;Lee, Wang-Hee;Mo, Changyeun;Cho, Byoung-Kwan
    • Journal of Biosystems Engineering
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    • v.40 no.4
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    • pp.345-358
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    • 2015
  • Southeast Asia, a typical tropical region, plays an important role in exporting a variety of fruits worldwide. The market for fresh fruits has been growing consistently, and this is a chance for Southeast Asian countries to increase their national income. However, export of tropical fruits has limitations such as a short shelf life and difficulty in maintaining the quality because of tropical climate conditions and undeveloped postharvest technologies in Southeast Asia. An important objective for developing postharvest technologies is to extend the shelf life of fresh fruits without deterioration in fruit quality. Therefore, it is essential to determine factors that affect the shelf life of fruits. The shelf life of tropical fruits is significantly dependent on the inherent properties of the fruits, extrinsic conditions, postharvest treatment, and microbial contamination. Recently, Southeast Asian countries have supported agricultural research groups for developing new postharvest technologies and minimizing postharvest losses and maintaining export fruit quality so that the total sales of tropical fruit farms can increase. This review introduces how the primary factors for extending the shelf life of tropical fruits can be determined and discusses the development of postharvest technologies for tropical fruits in Southeast Asian countries.

Non-Conventional Roughages in Tropical and Sub-Tropical Asian-Australasian Countries - Review -

  • Nitis, I.M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.12 no.3
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    • pp.449-459
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    • 1999
  • Non-conventional roughage (NCR) is shrub and tree fodders, crop residues and agroindustrial oy-products which is not commonly used as livestock feed traditionally and commercially. Eventhough many sources of NCR is available, the farmers perceptions on NCR not only vary from country to country in tropical and sub-tropical Asian-Australasian countries, but also vary from region to region within the country. Chemical composition and nutritive value of NCR are not only vary from species to species but also vary between species within the genera, between provenances/cultivars within the species and such variations are affected by season, climatic zone, topography and land utilization. The nutritive value of NCR can be improved by physical, chemical and biological treatments and conservation. Feeding NCR to ruminant and non-ruminant is not only improve performance of the livestock but also economically feasible. Future direction of NCR is inventarization, exchange information through NCR information centre, integration with either agrisilvicultural, agrisilvipastoral or silvipastoral system, and use of genetic engineering to produce high quality NCR that ultimately become conventional roughage for agroindustry and agribissiness.

Functional characterization of Clonorchis sinensis choline transporter

  • Jeong Yeon Won;Johnsy Mary Louis;Eui Sun Roh;Seok Ho Cha;Jin-Hee Han
    • Parasites, Hosts and Diseases
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    • v.61 no.4
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    • pp.428-438
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    • 2023
  • Clonorchis sinensis is commonly found in East Asian countries. Clonorchiasis is prevalent in these countries and can lead to various clinical symptoms. In this study, we used overlap extension polymerase chain reaction (PCR) and the Xenopus laevis oocyte expression system to isolate a cDNA encoding the choline transporter of C. sinensis (CsChT). We subsequently characterized recombinant CsChT. Expression of CsChT in X. laevis oocytes enabled efficient transport of radiolabeled choline, with no detectable uptake of arginine, α-ketoglutarate, p-aminohippurate, taurocholate, and estrone sulfate. Influx and efflux experiments showed that CsChT-mediated choline uptake was time- and sodium-dependent, with no exchange properties. Concentration-dependent analyses of revealed saturable kinetics consistent with the Michaelis-Menten equation, while nonlinear regression analyses revealed a Km value of 8.3 µM and a Vmax of 61.0 pmol/oocyte/h. These findings contribute to widen our understanding of CsChT transport properties and the cascade of choline metabolisms within C. sinensis.

Monogastric Animal Production Systems in Small Farms in Tropical Countries - Review -

  • Saadullah, M.;Saad, T.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.3
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    • pp.401-412
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    • 2000
  • Like other livestock, monogastric animals are essential components of the farming systems in the tropical countries. Pigs, chicken and ducks are by far the most important animals in the culture of the peoples of developing countries in the tropics. Traditionally these animals are raised in small farms and they are also the bulk producers of meat, eggs etc. in the tropics. In many countries the farmers of these small farms are unable to meet the requirement set by financial institution and other loan giving agencies for agricultural loan. Thus, the small farmers can get neither the opportunity to generate sufficient income to support the family nor to extend the livestock activities. The production systems are characterized by small number of animals with no or minimal inputs, low outputs and periodic destruction of animals by disease. Typically the litter size or flocks are small in number with each household containing 5-6 pigs and 7-10 poultry. Animals are owned by individual households and mostly maintained under a scavenging systems with little or no inputs for housing, feeding or health care. Because of the nature of this production system, productivity of these animals is rather low. The low level of inputs is due to a lack of capital and a low risk oriented outlook. The feed resource base for monogastric is scavenging and consists of household waste, roots and tuber, grain by-products and anything edible found in the immediate environment. Usually farmers select breeding gilts from their own female piglets or to a lesser extent, buy them from neighbors for natural mating. As regards poultry attempts have been made to increase egg and meat production by improving local poultry birds by upgrading and crossbreeding with exotic germ plasma in the tropics. Animal disease present a major constraint to animal production in the tropical region and the extent of the losses due to disease is very high.

Practical Algorisms for PCR-RFLP-Based Genotyping of Echinococcus granulosus Sensu Lato

  • Kim, Hye-Jin;Yong, Tae-Soon;Shin, Myeong Heon;Lee, Kyu-Jae;Park, Gab-Man;Suvonkulov, Uktamjon;Kovalenko, Dmitriy;Yu, Hak Sun
    • Parasites, Hosts and Diseases
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    • v.55 no.6
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    • pp.679-684
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    • 2017
  • Echinococcus granulosus sensu lato (s.l.) is a causative agent of cystic echinococcosis or cystic hydatid disease in humans and domestic and wild animals. The disease is a serious health problem in countries associated with poverty and poor hygiene practices, particularly in livestock raising. We introduced a practical algorism for genotyping the parasite, which may be useful to many developing countries. To evaluate the efficiency of the algorism, we genotyped 3 unknown strains isolated from human patients. We found that unknowns 1 and 3 were included in G1, G2, and G3 genotypes group and unknown 2 was included in G4 genotype (Echinococcus equinus) according to the algorisms. We confirmed these results by sequencing the 3 unknown isolates cox1 and nad1 PCR products. In conclusion, these new algorisms are very fast genotype identification tools that are suitable for evaluating E. granulosus s.l. isolated from livestock or livestock holders, particularly in developing countries.

Malaria Diagnosis: A Brief Review

  • Tangpukdee, Noppadon;Duangdee, Chatnapa;Wilairatana, Polrat;Krudsood, Srivicha
    • Parasites, Hosts and Diseases
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    • v.47 no.2
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    • pp.93-102
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    • 2009
  • Malaria is a major cause of death in tropical and sub-tropical countries, killing each year over 1 million people globally; 90% of fatalities occur in African children. Although effective ways to manage malaria now exist, the number of malaria cases is still increasing, due to several factors. In this emergency situation, prompt and effective diagnostic methods are essential for the management and control of malaria. Traditional methods for diagnosing malaria remain problematic; therefore, new technologies have been developed and introduced to overcome the limitations. This review details the currently available diagnostic methods for malaria.

Teak (Tectona grandis Linn. f.): A Renowned Commercial Timber Species

  • Palanisamy, K.;Hegde, Maheshwar;Yi, Jae-Seon
    • Journal of Forest and Environmental Science
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    • v.25 no.1
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    • pp.1-24
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    • 2009
  • Teak (Tectona grandis) is one of the most valuable timber yielding species in the world, with predominant distribution in tropical or sub-tropical countries. However, natural teak available only in few countries like India, Myanmar, Laos People's Democratic Republic and Thailand. Teak grows well in deep, well-drained alluvial soils, fairly moist, warm, tropical climate with pH ranges from 6.5-7.5. Teak is cultivated in many Asian, African and South American countries for timber production. The global teak plantations are estimated to be three million hectare with major share in India (44%) followed by Indonesia (33%). India is considered as richest genetic resources of teak with large areas of natural teak bearing forests (8.9 million ha), plantations (1.5 million ha), clonal seed orchards (1000 ha) and seed production areas (5000 ha). The studies on diversity of teak populations showed that teak is an out crossing species with major portion of diversity present within the populations. The productivity and quality of teak timber varies depending upon the site and environmental conditions. Teak wood is moderately heavy, strong and tough,straight grained, coarse textured and ring porous with specific gravity varies from 0.55 to 0.70. The sapwood is white to pale yellow in colour and clearly demarcated while heartwood is dark brown or dark golden yellow in colour. Teak is one of the most durable timbers in the world, practically, impervious to fungus and white ant attack and resistant to decay. Teak wood is used in ship and boat constructions, furnitures and aesthetic needs. Genetic improvement programmes have been undertaken in countries like Thailand, India, Malaysia and Indonesia. The programme includes provenance identification and testing, plus tree selection and clonal multiplication, establishment of seed orchards and controlled hybridization. Several aspects like phenology, reproductive biology, fruit characteristics, silvicultural practices for cultivation, pest and diseases problems, production of improved planting stock, harvesting and marketing, wood properties and future tree improvement strategy to enhance productivity have been discussed in this paper.

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Corrosion of Steel and Zinc in Tropics

  • Hue Nguyen Viet;Kwon Sik Chol
    • Journal of the Korean institute of surface engineering
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    • v.36 no.3
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    • pp.272-283
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    • 2003
  • Mild steel and zinc specimens were tested in five atmospheric testing sites of Vietnam in order to collect the corrosion databank as well as to study the corrosion mechanism in tropical conditions, in period of 1997-2000. The results obtained showed that the corrosion rate of steel is in the range of $10-50\;{\mu}m/year$ and of zinc is of $1-5\;{\mu}m/year$. They are interpretable in the comparison with the data obtained in different countries in the South East Asian as well as previous reports of Vietnamese nation project In atmospheric corrosion. The main factors affecting the corrosion in Vietnam tropical conditions are TOW (time of wetness) and salinity. The relationship between sulfur dioxide and corrosion of metals, particularly, zinc was not found clearly. An explanation was suggested about the complex effect of different pieces present in tropical atmosphere and about the alternative of the dominant factors such as humidity, salinity or temperature.

Prevalence and Alternative Treatment of Head-Lice Infestation in Rural Thailand: A Community-Based Study

  • Singhasivanon, On-uma;Lawpoolsri, Saranath;Mungthin, Mathirut;Yimsamran, Surapon;Soonthornworasiri, Ngamphol;Krudsood, Srivicha
    • Parasites, Hosts and Diseases
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    • v.57 no.5
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    • pp.499-504
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    • 2019
  • Head-lice infestation, pediculosis capitis, remains a public-health burden in many countries. The widely used first-line pediculicides and alternative treatments are often too costly for use in poor socio-economic settings. Ivermectin has been considered an alternate treatment for field practice. This study was composed of 2 parts, a cross-sectional survey and an intervention study. The main objectives were to determine the prevalence and potential factors associated with head-lice infestation, and to evaluate the effectiveness and safety of oral ivermectin administration. A community-based cross-sectional survey was conducted among 890 villagers in rural areas along Thai-Myanmar border. Females with infestations were eligible for the intervention study, and 181 participated in the intervention study. A post-treatment survey was conducted to assess acceptance of ivermectin as a treatment choice. Data analysis used descriptive statistics and a generalized-estimation-equation model adjusted for cluster effect. The study revealed the prevalence of head-lice infestation was 50% among females and only 3% among males. Age stratification showed a high prevalence among females aged <20 years, and among 50% of female school-children. The prevalence was persistent among those with a history of infestation. The major risk factors were residing in a setting with other infected cases, and sharing a hair comb. The study also confirmed that ivermectin was safe and effective for field-based practice. It was considered a preferable treatment option. In conclusion, behavior-change communication should be implemented to reduce the observed high prevalence of head-lice infestation. Ivermectin may be an alternative choice for head-lice treatment, especially in remote areas.