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The origin of Borneo's elephants is controversial. Two competing hypotheses argue that they are either indigenous, tracing back to the Pleistocene, or were introduced, descending from elephants imported in the 16th-18th centuries. Taxonomically, they have either been classified as a unique subspecies or placed under the Indian or Sumatran subspecies. If shown to be a unique indigenous population, this would extend the natural species range of the Asian elephant by 1300 km, and therefore Borneo elephants would have much greater conservation importance than if they were a feral population. We compared DNA of Borneo elephants to that of elephants from across the range of the Asian elephant, using a fragment of mitochondrial DNA, including part of the hypervariable d-loop, and five autosomal microsatellite loci. We find that Borneo's elephants are genetically distinct, with molecular divergence indicative of a Pleistocene colonisation of Borneo and subsequent isolation. We reject the hypothesis that Borneo's elephants were introduced. The genetic divergence of Borneo elephants warrants their recognition as a separate evolutionary significant unit. Thus, interbreeding Borneo elephants with those from other populations would be contraindicated in ex situ conservation, and their genetic distinctiveness makes them one of the highest priority populations for Asian elephant conservation.
We quantified the allocation of net production to plant secondary metabolites (especially condensed tannins and lignins) to evaluate the investment into defense mechanisms of three tropical forest canopy species in Borneo vis-à-vis the resource availability hypothesis. In particular, we focused on Borneo ironwood (Eusideroxylon zwageri, Lauraceae), which seemed to employ an extreme defensive strategy. The wood of this species is extremely durable and has a high specific gravity with a very slow growth rate. The allocation to defense by Borneo ironwood was compared to two emergent species of Dipterocarpaceae, the dominant family in this forest community. We conducted shade-house experiments on seedlings under four controlled conditions (two light levels x two nutrient levels) and showed that the growth rate of E. zwageri was much lower than those of the other two species, and it allocated more of its net production to leaves and roots than to stems. The concentrations of condensed tannins and lignins were very high in the leaves and stems of this species, at about 20 and 30%, respectively. In total, E. zwageri allocated a maximum of about 35% of its net production to defensive substances (i.e., condensed tannins + lignins). In contrast, the two dipterocarp species allocated about 20-25% of their net production to defensive substances. The condensed tannins in E. zwageri help to prolong the lifespan of the leaves, and the lignins in the stems enhance the durability of the wood. Thus, although E. zwageri grows very slowly, the allocation to defensive substances seems to be an advantageous strategy for survival under dark conditions.
The mosquito, Aedes albopictus, has recently become established in a number of cities throughout the United States. An initial survey of allozyme and genotypic frequencies in U.S. populations (Black et al., 1988) revealed an extensive amount of local differentiation of populations and suggested that much genetic drift may have accompanied colonization. A study of gene flow was initiated in native habitats of Ae. albopictus in Malaysia to determine if the result observed in the U.S. was a consequence of colonization or simply followed the natural breeding structure of the species. Allelic and genotypic frequencies were monitored at ten enzymatic loci in 11 populations from peninsular Malaysia and Borneo. Multiple populations were sampled within the districts of Kuala Lumpur and Kuala Trengganu. Peninsular Malaysian and Borneo populations were strongly genetically differentiated. Allele frequencies were significantly different among and within districts in both regions. Variance in allele frequencies among all collections was partitioned into the variance among regions, districts within regions and collections within districts. Almost all of the variance within regions was attributable to local differentiation suggesting that genetic drift is an important component of the natural breeding structure of this species. This indicates that the large amounts of local differentiation found in U.S. populations was not a consequence of recent colonization.
Dental transfigurement, formerly termed dental mutilation, has been practised by many societies worldwide. This article gives many of the forms that have been attributed to the indigenes of the island of Borneo. The method has been performed by review of anthropological books, sparse dental references, Borneo research literature, and popular writing.
We report a case of leptospirosis infected in Sabah, Borneo island, Malaysia. The case is 25-year-old male who had participated in the EcoChallenge Sabah 2000 Expedition Race, a multisport event held during August 20 to September 3, 2000 at various sites in Sabah in Malaysian Borneo. He developed a high fever and headache on September 7, and he was admitted to our hospital on September 9. On admission he also had conjunctivitis and myalgias. Laboratory findings on admission revealed leukocytosis with left shift, slightly elevated transaminase levels, high CRP levels and proteinuria. Plasmodium spp. were negative on blood smears, and no bacteria were isolated from blood and feces cultures. We performed the laboratory tests for leptospirosis, based on the information about the probable leptospirosis outbreak among athletes who participated in the EcoChallenge Race, however both Leptospira antigens and antibodies were negative at that time. We diagnosed leptospirosis clinically because he manifested persistent symptoms, and minocycline 100 mg b.i.d. was administered intravenously resulting in excellent efficacy. Serum antibody tests by microscopic agglutination test (MAT) at convalescent stage revealed significant increased antibodies against Leptospira interrogans serovar hebdomadis, and the diagnosis of leptospirosis was confirmed. Infectious diseases have been global and it is important to have information concerning worldwide infectious disease situations as much as possible for accurate diagnosis.
Myliocotyle borneoensis sp. n. and M. multicrista sp. n. (Monocotylidae: Heterocotylinae) are described from the gills of the mottled eagle ray, Aetomylaeus maculatus (Gray), and the banded eagle ray A. nichofii (Bloch et Schneider) (Myliobatidae), respectively, collected from the northern coast of Malaysian Borneo. These are the first monogeneans to be described on elasmobranchs from Borneo. The formerly monotypic Myliocotyle (for M. pteromylaei) was distinguished from other monocotylids by the distribution and morphology of the eight sclerotised dorsal haptoral accessory structures and the morphology of the male copulatory organ. However, we have determined that M. pteromylaei has ten structures on the dorsal surface of the haptor. Myliocotyle borneoensis is distinguished from M. pteromylaei by the morphology of the male copulatory organ and its accessory piece. Myliocotyle multicrista has 12 sclerotised dorsal haptoral accessory structures and a male copulatory organ with two accessory pieces. Additional sclerotised ridges across the ventral surfaces of each loculus (except the posterior-most pair) are also present in M. multicrista. The diagnosis for Myliocotyle is revised given our discovery of additional dorsal haptoral accessory structures in the type species and to accommodate other new characters of the two new species. Anterior secretions of Myliocotyle are discussed.
The resistant levels of the 4 strains of the housefly collected in Borneo to six insecticides, namely DDT, Chrysron, DDVP, Baytex, Sumithion and Diazinon, were examined. It was found that most housefly population in Borneo showed a higher susceptibility than that of the Takatsuki strain of Japan, especially to DDT.
Beta-thalassemia major is one of the commonest genetic disorders in South-East Asia. The spectrum of beta-thalassemia mutations in the various ethnic sub-populations on the island of Borneo is unknown. We studied 20 Dusun children from the East Malaysian state of Sabah (North Borneo) with a severe beta-thalassemia major phenotype, using a combination of Southern analysis, polymerase chain reaction analysis and direct sequencing. We found the children to be homozygous for a large deletion, which has a 5' breakpoint at position -4279 from the cap site of the beta-globin gene (HBB) with the 3' breakpoint located in a L1 family of repetitive sequences at an unknown distance from the beta-globin gene. This was similar to a recent finding of a large deletion causing beta-thalassemia first described in unrelated beta-thalassemia heterozygotes of Filipino descent. This report describes the first 20 families with homozygosity of the deletion causing a severe phenotype. It provides the first information on the molecular epidemiology of beta-thalassemia in Sabah. This finding has implications for the population genetics and preventative strategies for beta-thalassemia major for nearly 300 million individuals in South-East Asia.
A comparison of mitochondrial DNA sequences was undertaken for two genes among orangutans from Borneo and Sumatra. The distribution of haplotypes among 42 individuals for NADH dehydrogenease subunit 3 and 39 individuals for cytochrome B was used to infer population structure. The haplotypes among all Bornean orangutans form a cluster of closely related individuals for both genes, with two distinct haplotypes occupying different regions of the island. Sumatran haplotypes fall into three distinct, and highly diverged, groups. Strikingly, one of the Sumatran haplotypes shares sequence identity with the most widespread Bornean haplotype. This haplotype distribution is considered in the context of the highly complex geological history for the area around the Malay Archipelago. Alternating periods of geographic isolation and reunion, resulting from glacially induced land bridge formation, presented substantial opportunity for population dispersal between periodically isolated demes. We present a paleodispersal model that is consistent with genetic, geological, paleoecological, and fossil data. The disparity of sequences present in orangutan populations argues against a simple Sumatra-Borneo dichotomy. Our evidence, and that of others, suggests that the Sumatran population alone contains the remnants of at least three separate lineages.
Decacotyle cairae n. sp. (Monogenea: Monocotylidae) is described from the gills of an unidentified species of Pastinachus collected in the South China Sea off Sematan and Mukah, Sarawak, Borneo, Malaysia. D. cairae can be distinguished from the other six members of the genus by the presence of two simple unsclerotised accessory structures on the dorsal surface of the haptor in combination with a long, narrow, looping male copulatory organ. The host specimens of Pastinachus collected in Borneo also appear to be a new species and the monogenean data support this conclusion. A key to species of Decacotyle is given and their host-specificity is discussed.
Empruthotrema stenophallus n. sp. (Monogenea: Monocotylidae) is described from specimens from the nasal tissue of the blue-spotted maskray Dasyatis kuhlii (Muller and Henle, 1841) collected in shallow waters off Pulau Banggi and Pulau Mabul, Sabah, Borneo, Malaysia. This is the first monogenean species to be described from an elasmobranch collected from Sabah. E. stenophallus can be distinguished from the other 6 members of the genus by the morphology of the sclerotized male copulatory organ, which is narrow, short, and distally tapered. E. dasyatidis Whittington and Kearn, 1992, previously documented from the nasal tissue of several of elasmobranch species from Australia, is recorded from 8 host species distributed around Malaysian Borneo. These represent new host and locality records for this monocotylid. The difficulties in identifying species of Empruthotrema and the apparent lack of host specificity by some members of the genus are discussed.
BACKGROUND: Pediculiasis is treated aggressively in the United States, mainly with permethrin- and pyrethrin-containing pediculicides. Increasingly frequent anecdotal reports of treatment failure suggest the emergence of insecticidal resistance by these lice. OBJECTIVE: To confirm or refute the susceptibility of head lice sampled in the United States to permethrin. DESIGN: Survey. Head lice were removed from children residing where pediculicides are readily available and where such products are essentially unknown. Their survival was compared following exposure to residues of graded doses of permethrin in an in vitro bioassay. SETTING: School children from Massachusetts, Idaho, and Sabah (Malaysian Borneo). SUBJECTS: In the United States, 75 children aged 5 to 8 years. In Sabah, 59 boys aged 6 to 13 years. Virtually all sampled US children had previously been treated with pediculicides containing pyrethrins or permethrin; none of the Sabahan children were so exposed. MAIN OUTCOME MEASURE: Survival of head lice exposed to permethrin. RESULTS: Permethrin did not affect head lice sampled from chronically infested US children who had previously been treated for pediculiasis. The slope of the dose-response regression line for these lice did not differ significantly from zero (P = .66). This pediculicide immobilized lice sampled in Sabah. Mortality correlated closely with permethrin concentration (P = .008). CONCLUSIONS: Head lice in the United States are less susceptible to permethrin than are those in Sabah. The pyrethroid susceptibility of the general population of head lice in the United States, however, remains poorly defined. Accordingly, these relatively safe over-the-counter preparations may remain the pediculicides of choice for newly recognized louse infestations.
We have examined how the structure and function of a forest ecosystem change with topography (lower-slope versus ridge) and how the changes are modified by nutrient availability depending on geological substrate (Quaternary and Tertiary sedimentary rocks and ultrabasic rock) in the tropical montane rain forests of Mt. Kinabalu (Borneo) where climate is humid and aseasonal. Reflecting the difference in site age and parent rock, the pool size of soluble-P and inorganic-N in topsoil decreased from Quaternary sedimentary >Tertiary sedimentary >ultrabasic rock on the lower-slope, and they decreased from the lower-slope to the ridge on all substrates. Forest structural attributes [stature, above-ground biomass, and leaf area index (LAI)] decreased in the order of Quaternary sedimentary >Tertiary sedimentary >ultrabasic rock in association with soil nutrients on the lower-slopes, and decreased upslope consistently on each of the three substrates. Functional attributes [above-ground net primary productivity (ANPP) and decomposition rate] demonstrated similar patterns to structure. ANPP significantly correlated with LAI among the six sites, while net assimilation rate (ANPP divided by LAI assuming an even productivity between above vs below-ground system) was nearly constant. Therefore, ANPP could be explained primarily by LAI. Topographical change in LAI could be explained by leaf mass per area (LMA) combined with stand-level leaf biomass. LMA increased upslope on all substrates in association with the decrease in individual leaf area. Stand-level leaf biomass decreased upslope on all substrates but the Tertiary sedimentary rock. Our study demonstrated that topography and geological substrates interactively affected forest structure and processes. The effect of topography on forest structure and processes was greater on nutrient-rich substrates than on poor substrates, and the effect of geological substrate was greater on lower-slopes than on ridges.
Historical and anthropological studies of non-Western societies have concluded that there is no cultural group in which the use of tobacco is substantially more common among women, although there are societies without appreciable gender differences in tobacco use. Interpretations of this pattern, influenced by well-documented changes in the United States, have concentrated on the greater use of tobacco by men, attributing it to aspects of traditional sex roles such as male power and male control of scarce resources. This analysis places more weight on the changes in both sex roles and local economies which accompany the transition from subsistence-orientated production to a market economy. Among the Lahanan, a relatively isolated group of horticulturalists living in Central Borneo, adult women, who control the production and distribution of tobacco, are more likely than men to smoke are also heavier smokers. Increasing contact with the industrialised world is rapidly changing this pattern with young men switching to manufactured cigarettes and the better educated of the young women not smoking at all. This study suggests that gender differences in tobacco use are probably inconsequential in societies where tobacco is grown for home consumption, but become increasingly substantial as manufactured cigarettes replace local tobacco products.
Traditional remedies have been a source of important antimalarial drugs and continue to provide novel and effective treatments, both where pharmaceuticals are not available and where the disease is increasingly resistant to commonly prescribed drugs. The Kenyah of the Apo Kayan, a remote forested plateau in Indonesian Borneo, use 17 malaria remedies derived from natural sources. A quantitative analysis of the relationship between a 'local importance value' index for each malaria remedy (IVmal) and inhibition of cultured Plasmodium falciparum by ethanolic extracts supports the hypothesis that the degree of local consensus about a given remedy is a good indicator of its potential biological efficacy. Our results confirm the rational selection and use of traditional remedies for malaria by the Kenyah. We have identified target species for further research directed toward safe and effective treatments for malaria.
Sanguilevator yearsleyi n. gen., n. sp. and Cathetocephalus resendezi n. sp. are described from the Broadfin shark, Lamiopsis temmincki, in Malaysian Borneo and Carcharhinus leucas in Mexico, respectively. The new genus is unusual in its possession of internal chambers and channels in its scolex that appear to house extensive quantities of host white and red blood cells, respectively. Histology reveals an extremely intimate association between host tissue and the surface of the apical pad of the scolex. Positive staining with periodic acid-Schiff of the surface of the pad of the scolex and the linings of the chambers and channels suggests that an adhesive substance may be produced in these regions. However, explanations for how and why host blood cells come to reside within the scolex remain elusive. Cathetocephalus resendezi n. sp. is distinctive in the form of the papillae in the papillate band of the scolex and also in the inconspicuous nature of the rugose base of the scolex. Scanning electron microscopy of both new taxa as well as Cathetocephalus thatcheri, Cathetocephalus australis and an undescribed species of Cathetocephalus collected from Carcharhinus amboinensis in Australia, suggests that the papillae surrounding the pad of the scolex are of significant taxonomic utility in distinguishing among species in these groups. Parsimony and Bayesian analyses of sequence data (766 bases of 18S rDNA and 405 bases of 28S rDNA) generated from ethanol preserved specimens of C. thatcheri and S. yearsleyi, when compared with equivalent data available for 40 cestode species in GenBank, resulted in trees that support previous propositions that Cathetocephalus should be placed in the order Cathetocephalidea. The results suggest that Sanguilevator should also be considered to belong to this order.
Thirty-two patients reporting to the Lundu District Hospital, Sarawak, Malaysian Borneo, with uncomplicated falciparum malaria were recruited into a multifaceted study to assess treatment response. Following combined chloroquine and sulphadoxine/pyrimethamine treatment the patients were followed for 28 days according to the World Health Organisation in vivo drug response protocol. The in vivo study revealed that 13 (41%) of the patients had a sensitive response to treatment, five (16%) cleared asexual stage parasites but had persistent gametocytes, 11 (34%) had RI type resistance and three (9%) had RII type resistance requiring quinine intervention before day 7 for parasite clearance. Although clinically insignificant, patients with persistent gametocytes, surviving chloroquine and sulphadoxine/pyrimethamine treatment during maturation, were placed in the reduced response to treatment group for analysis. Allelic typing detected 100% prevalence of the pfcrt K76T marker associated with chloroquine resistance and 78% prevalence of the pfdhfr NRNL haplotype associated with sulphadoxine/pyrimethamine treatment failure. High serum chloroquine levels and pfdhfr haplotypes with <or=2 point mutations were independently associated with a sensitive response to treatment. However four patients in the sensitive response group had both low serum chloroquine levels and the pfdhfr NRNL haplotype. A degree of immunity, consistent with malaria endemicity, may account for the apparently paradoxical presence of markers of drug resistance in the sensitive group.