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PubMed1997

Sustainable urbanization in Vietnam.

"This paper examines the nature of [urban-based economic growth in Vietnam] and contends that the present size of Ho Chi Minh City and Hanoi are much greater than official figures suggest. It then goes on to review the situation with regard to urban poverty, basic needs and the environment to illustrate the extent to which this unacknowledged growth is not only threatening the sustained expansion of those cities, but also the sustainability of the economic growth on which the country is so reliant."

Asia↗
PubMed2001

Immunoglobulin subclass responses of wild brown rats to Sarcocystis singaporensis.

Immunoglobulin subclass responses of wild brown rats (Rattus norvegicus) from southeastern Asia to the endemic cyst-forming coccidian Sarcocystis singaporensis were characterised. The antibody response of brown rats to wild-type parasites (high reproductive capacity) showed a Th1 profile during acute infection, namely elevated concentrations of parasite-specific IgG2b and IgG2c and absence of IgG1. Chronic infection (bradyzoite development) resulted in a mixed Th1/Th2 pattern whereby significant concentrations of IgG1 appeared. A primary infection with 1000 sporocysts eight days before challenge induced protection, accompanied by significant concentrations of IgA and IgG2, particularly IgG2a. Western blot analysis of rat sera, using sporozoite and bradyzoite-extracts as antigen, revealed that IgG1, IgG2a, and IgG2b predominantly recognised molecules between 70-80 kDa in one or the other stage. Some of the antibodies were possibly directed against a 79 kDa heat shock protein of sporozoites. An apparent unresponsiveness to molecules in the low molecular weight range, particularly of bradyzoite antigens, was observed. This was abrogated by infection of rats with an avirulent strain of S. singaporensis (low reproductive capacity) indicating that a parasite that was less adapted to its host provoked a stronger immune response. These results suggest the existence of an immune evasion strategy used by Sarcocystis and show that wild rodents may be suitable as immunological research objects, reflecting the natural situation.

Animals↗
PubMed2001

Reduction of transmission stages concomitant with increased host immune responses to hypervirulent Sarcocystis singaporensis, and natural selection for intermediate virulence.

Parasite virulence (pathogenicity depending on inoculum size) and host immune reactions were examined for the apicomplexan protozoan Sarcocystis singaporensis. This parasite is endemic in southeastern Asia and multiplies as a proliferation (merozoite) and transmission stage (bradyzoite) in rats. Virulence in wild brown rats of parasites freshly isolated in the wild (wild-type) was surprisingly constant within the endemic area and showed an intermediate level. In contrast, serially passaged parasites either became avirulent or virulence increased markedly (hypervirulence). Production of transmission stages was maximal for the wild-type whereas numbers were significantly reduced for hypervirulent and avirulent (shown in a previous study) parasites. Analyses of B and T cell immunity revealed that immune responses of WKY rats to the transmission stage were significantly higher for hypervirulent than for wild-type parasites. These results suggest that it is the immune system of the host that is not only responsible for reduction of transmission stages in individual rats, but also could act as a selective force that maintains intermediate virulence at the population level because reduction of muscle stages challenges transmission of S. singaporensis to the definitive host. Collectively, the presented data support evolutionary theory, which predicts intermediate rates of parasite growth in nature and an 'arms race' between host immunity and parasite proliferation.

Animals↗
PubMed2001

Glutoxylon Chowdhury (Anacardiaceae): the first record of fossil wood from Bangladesh.

This paper documents the first record of silicified fossil wood from a previously undescribed wood-rich horizon in the Sitakund Anticline, Eastern Bangladesh. The outcrop is composed of cross-stratified, fine-medium grained sandstones with bidirectional cross stratification indicative of a tidal environment, deposited ca. 5-5.2 million years before present (Miocene/Pliocene). The wood is characterised by large solitary vessels with alternate intervascular pits, banded parenchyma, uniseriate rays, and multiseriate rays with one radial canal per ray. This character combination closely resembles the wood of extant Gluta L. of the Anacardiaceae. This specimen has been assigned to the organ genus Glutoxylon Chowdhury erected for fossil woods with anatomical similarity to Gluta (including Melanorrhoea Wall.). The excellent preservation of this mature wood specimen illustrates the potential for using fossil wood from the Sitakund locality for palaeoecological studies in terms of biodiversity and adaptational response to climate change. Moreover such investigations of fossil woods from Bangladesh will compliment studies undertaken on fossil plants in other parts of Central and Southeastern Asia which will further the understanding of plant migration routes between India and Southeast Asia during the Tertiary.

Journal Article↗
PubMedDate not supplied

Aquatic modules for bioregenerative life support systems based on the C.E.B.A.S. biotechnology [correction of biotechnilogy].

Most concepts for bioregenerative life support systems are based on edible higher land plants which create some problems with growth and seed generation under space conditions. Animal protein production is mostly neglected because of the tremendous waste management problems with tetrapods under reduced weightlessness. Therefore, the "Closed Equilibrated Biological Aquatic System" (C.E.B.A.S.) was developed which represents an artificial aquatic ecosystem containing aquatic organisms which are adapted at all to "near weightlessness conditions" (fishes Xiphophorus helleri, water snails Biomphalaria glabrata, ammonia oxidizing bacteria and the rootless non-gravitropic edible water plant Ceratophyllum demersum). Basically the C.E.B.A.S. consists of 4 subsystems: a ZOOLOGICAL (correction of ZOOLOGICASL) COMPONENT (animal aquarium), a BOTANICAL COMPONENT (aquatic plant bioreactor), a MICROBIAL COMPONENT (bacteria filter) and an ELECTRONICAL COMPONENT (data acquisition and control unit). Superficially, the function principle appears simple: the plants convert light energy into chemical energy via photosynthesis thus producing biomass and oxygen. The animals and microorganisms use the oxygen for respiration and produce the carbon dioxide which is essential for plant photosynthesis. The ammonia ions excreted by the animals are converted by the bacteria to nitrite and then to nitrate ions which serve as a nitrogen source for the plants. Other essential ions derive from biological degradation of animal waste products and dead organic matter. The C.E.B.A.S. exists in 2 basic versions: the original C.E.B.A.S. with a volume of 150 liters and a self-sustaining standing time of more than 13 month and the so-called C.E.B.A.S. MINI MODULE with a volume of about 8.5 liters. In the latter there is no closed food loop by reasons of available space so that animal food has to be provided via an automated feeder. This device was flown already successfully on the STS-89 and STS-90 spaceshuttle missions and the working hypothesis was verified that aquatic organisms are nearly not affected at all by space conditions, i.e. that the plants exhibited biomass production rates identical to the sound controls and that as well the reproductive, and the immune system as the embryonic and ontogenic development of the animals remained undisturbed. Currently the C.E.B.A.S. MINI MODLULE is prepared for a third spaceshuttle flight (STS-107) in spring 2001. Based on the results of the space experiments a series of prototypes of aquatic food production modules for the implementation into BLSS were developed. This paper describes the scientific disposition of the STS-107 experiment and of open and closed aquaculture systems based on another aquatic plant species, the Lemnacean Wolffia arrhiza which is cultured as a vegetable in Southeastern Asia. This plant can be grown in suspension culture and several special bioreactors were developed for this purpose. W. arrhiza reproduces mainly vegetatively by buds but also sexually from time to time and is therefore especially suitable for genetic engineering, too. Therefore it was used, in addition, to optimize the C.E.B.A.S. MINI MODULE to allow experiments with a duration of 4 month in the International Space Station the basic principle of which will be explained. In the context of aquaculture systems for BLSS the continuous replacement of removed fish biomass is an essential demand. Although fish reproduction seems not to be affected in the shortterm space experiments with the C.E.B.A.S. MINI MODULE a functional and reliable hatchery for the production of siblings under reduced weightlessness is connected with some serious problems. Therefore an automated "reproduction module" for the herbivorous fish Tilapia rendalli was developed as a laboratory prototype. It is concluded that aquatic modules of different degrees of complexity can optimize the productivity of BLSS based on higher land plants and that they offer an unique opportunity for the production of animal protein in lunar or planetary bases.

Ammonia↗
PubMed2002

Epidemiology of hepatocellular carcinoma.

Because of its high incidence in many of the most populous countries in the world, its often fulminant course, poor response to conservative treatment, low resectabilty rate when symptomatic, high recurrence rate after resection and liver transplantation, and grave prognosis, hepatocellular carcinoma is now regarded as one of the major malignant diseases. Hepatocellular carcinoma is the most common primary malignant tumour of the liver. Relative to other tumours, it ranks fifth in overall frequency (fifth in men and eighth in women) and fourth in annual mortality rate. An estimated 372,000 new cases of hepatocellular carcinoma are diagnosed each year, constituting 4.6% of all new human cancers (6.3% in men; 2.7% in women). The annual mortality rate from the tumour is virtually the same as its annual incidence. The highest incidences occur in eastern and southeastern Asia, some of the Western Pacific islands, and sub-Saharan Africa. Intermediate incidences are found in eastern and southern Europe, the Caribbean, Central America, and Western Asia. Hepatocellular carcinoma is uncommon in the remaining countries. Men are affected more often than are women. The incidence generally increases with increasing age, although there is a definite shift towards a younger age distribution in black African and ethnic Chinese populations.

Age Factors↗
PubMed1998

Migration, self-selection and earnings in Philippine rural communities.

"Estimated returns to schooling investments can be misleading if migration causes significant shifts in population distribution across time. Data gathered in rural Philippine communities show that the more educated and experienced individuals are more likely to outmigrate, causing a sample selection bias in the estimation of wage equations. The observed wages were then lower than the conditional population mean of an entire cohort residing originally in the area. Controlling for self-selection, the wage returns to schooling and experience were higher, Finally, the sample selectivity variable accounts substantially for the difference in the wages of men and women."

Asia↗
PubMed1998

The determinants of child mortality in the Philippines: estimation of a structural model.

"This paper employs a longitudinal data set from the Philippines to estimate a structural model of the determinants of infant mortality. To control for the endogeneity of some explanatory variables, a set of reduced form equations for these outcomes is estimated simultaneously with the mortality hazard. A non-parametric discrete factor method is used to control for common unobservable factors in the error terms. Birth interval and parity lose explanatory power once biological measures are considered in the model. The results indicate significant correlations across the equations' error terms. The significant effects of breastfeeding and growth on mortality are quantified in simulation experiments." The data are from a longitudinal survey conducted in metropolitan Cebu between 1983 and 1986.

Asia↗
PubMed1999

Stratified partial likelihood estimation.

When multiple durations are generated by a single unit, they may be related in a way that is not fully captured by the regressors. The omitted unit-specific variables might vary over the durations. They might also be correlated with the variables in the regression component. The authors propose an estimator that responds to these concerns and develop a specification test for detecting unobserved unit-specific effects. Data from Malaysia reveal that concentration of child mortality in some families is imperfectly explained by observed explanatory variables, and that failure to control for unobserved heterogeneity seriously biases the parameter estimates.

Asia↗
PubMed2003

Pharmacological effect and toxicity of alkaloids from Gelsemium elegans Benth.

Gelsemium elegans Benth. (Loganiaceae), a toxic plant indigenous to southeastern Asia, is well known among hilltribes as an effective means for committing suicide. A crude alkaloidal fraction from its leaves was isolated by conventional acid-base extraction. Tests in animals showed that the alkaloids exerted analgesic and anti-inflammatory effects. At a lethal dose, the alkaloids produced violent clonic convulsions that led to respiratory failure. Since the convulsions could be prevented by pentobarbital or diazepam and potentiated by reserpine, it is postulated that the alkaloids act centrally against GABA action.

Alkaloids↗
PubMed1999

The impact of overseas labour migration on rural Thailand: regional, community and individual dimensions.

"This paper provides a case study of the impact at origin of recent labour migration from rural Thailand to East Asian destinations. It does so through survey information on 63 villages and detailed biographic interviews with recently returned workers. It is concluded that work abroad is regarded by migrants as a strategy of life support; it is sometimes life-enhancing, but only rarely life-changing."

Asia↗
PubMed1999

[Children of foreign origin adopted in France. Analysis of 68 cases during l2 years at the University Hospital Center of Tours].

BACKGROUND: The number of children of foreign origin adopted in France has increased in the past 15 years. The aim of this study was to analyse distinctive features and medical problems associated with international adoption. PATIENTS AND METHODS: The files of 68 foreign-origin adopted children who attended or were admitted to the Medical and Nutrition Unit of the Pediatric Hospital in Tours between January 1st 1986 and December 31st 1997, were studied retrospectively. Various parameters were analysed: age at first consultation, age at adoption, country of origin and health problems, especially nutritional status, infectious diseases, growth and development. RESULTS: In the majority of cases, children were adopted before 12 months of age (61.2%), particularly before six months of age (49.3%). The children came mainly from Africa and countries in the Indian Ocean (48.5%), and from Southeastern Asia (33.9%). Malnutrition was frequent in children from Africa. Twenty-one children (30.9%) presented with severe malnutrition characterized by weight less than the mean-2SD for height and required hospitalization. No children had congenital hypothyroidism, hyperphenylalaninemia, nor were HIV positive. Some patients had infectious diseases: 11 Hepatitis B, four congenital syphilis and six tuberculosis, with favorable outcomes after treatment. The other most frequent diseases were acute diarrhea, chronic diarrhea, intestinal parasites, and scabies, varying according to countries. Three girls adopted from southern Asia developed precocious puberty. Growth and psychomotor development were satisfactory overall, but abnormalities were observed in 15 children (22.1%), which is higher than in the general population. CONCLUSION: The expansion of international adoption with distinctive diseases proves the importance of a checkup as soon as possible after the arrival of these children in France. This checkup has to include nutritional and general evaluation and supplementary tests, especially for specific serology and vaccination status. Following this, it would be possible to propose a suitable follow-up to the adoptive parents.

Adoption↗
PubMed2004

Molecular phylogenetic relationships among Lemnaceae and Araceae using the chloroplast trnL-trnF intergenic spacer.

We test competing hypotheses of relationships among Aroids (Araceae) and duckweeds (Lemnaceae) using sequences of the trnL-trnF spacer region of the chloroplast genome. Included in the analysis were 22 aroid genera including Pistia and five genera of Lemnaceae including the recently segregated genus Landoltia. Aponogeton was used as an outgroup to root the tree. A data set of 522 aligned nucleotides yielded maximum parsimony and maximum likelihood trees similar to those previously derived from restriction site data. Pistia and the Lemnaceae are placed in two separate and well-supported clades, suggesting at least two independent origins of the floating aquatic growth form within the aroid clade. Within the Lemnaceae there is only partial support for the paradigm of sequential morphological reduction, given that Wolffia is sister to Wolffiella+Lemna. As in the results of the restriction site analysis, pantropical Pistia is placed with Colocasia and Typhonium of southeastern Asia, indicative of Old World affinities. Branch lengths leading to duckweed terminal taxa are much longer relative to other ingroup taxa (including Pistia), evidently as a result of higher rates of nucleotide substitutions and insertion/deletion events. Morphological reduction within the duckweeds roughly correlates with accelerated chloroplast genome evolution.

Chloroplasts↗
PubMed1998

Frugivory and seed dispersal by vertebrates in the Oriental (Indomalayan) Region.

Current knowledge of frugivory and seed dispersal by vertebrates in the Oriental Region is summarized. Some degree of frugivory has been reported for many fish and reptile species, almost half the genera of non-marine mammals and more than 40% of bird genera in the region. Highly frugivorous species, for which fruit dominates the diet for at least part of the year, occur in at least two families of reptiles, 12 families of mammals and 17 families of birds. Predation on seeds in fleshy fruits is much less widespread taxonomically: the major seed predators are colobine monkeys and rodents among the mammals, and parrots, some pigeons, and finches among the birds. Most seeds in the Oriental Region, except near its northern margins, are dispersed by vertebrate families which are endemic to the region or to the Old World. Small fruits and large, soft fruits with many small seeds are consumed by a wide range of potential seed dispersal agents, including species which thrive in small forest fragments and degraded landscapes. Larger, bigger-seeded fruits are consumed by progressively fewer dispersers, and the largest depend on a few species of mammals and birds which are highly vulnerable to hunting, fragmentation and habitat loss.

Animals↗
PubMed1988

Urbanization trends in Southeast Asia: some issues for policy.

"The apparent Southeast Asian paradox of fairly slow urbanization but rapidly growing urban populations is due to continued high rates of natural increase, especially in rural areas. Southeast Asian countries differ greatly in the nature of their urban hierarchies, and the appropriate policy goals and strategies therefore also differ. In countering growing urban primacy, indirect approaches emphasizing macro-economic and sectoral policies conducive to more dispersed patterns of urban growth have greater potential impact than direct attempts to slow the growth of large city populations. Greater decentralization of power and decision making over resource allocation is also needed."

Asia↗