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Displaying publications 201 - 220 of 228 in total

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Coccidia of Malaysian mammals: new host records and descriptions of three new species of Eimeria

Mullin SW, Colley FC, Stevens GS

J. Protozool., 1972 May;19(2):260-3.
PMID: 5032224
Matched MeSH terms: Ecology
Eimeria callosciuri n. sp. (Protozoa: Eimeriidae) from Prevost's squirrel Callosciurus prevostii Demarest, 1822 in Malaysia

Colley FC

J. Protozool., 1971 May;18(2):199-200.
PMID: 5104607
Matched MeSH terms: Ecology
Fulltext Food and water-borne protozoal diseases (FWBPD)

Baha Latif

Medical Health Reviews, 2009;2009(2):27-46.
MyJurnal

This review places emphasis on the food and water borne protozoal diseases like, cryptosporidiosis, giardiasis, cyclosporiasis, and toxoplasmosis which are endemic in many parts of the world. The article addresses cryptosporidiosis, giardiasis, cyclosporiasis, and toxoplasmosis. Cryptosporidium and Giardia are widespread in the environment and major outbreaks have occurred as a result of contaminated drinking water. Cyclospora has significance in the preparation and consumption of fresh food that have not received heat treatment. Toxoplasma gondii, transmission occur through contaminated water, unpasteurised milk and also the consumption of raw meat, which has been regarded as a major route of transmission to humans .These parasitic protozoa do not multiply in foods, but they may survive in or on moist foods for months especially in cool and damp environment. Their ecology makes control of these parasites difficult. Transmission, clinical manifestations, outbreaks, public health surveillance and control measures that are used for those diseases will be reviewed in this article.

Matched MeSH terms: Ecology
Distribution and ecological consideration of Breinlia booliati infecting wild rodents in Malaysia

Liat LB, Wah MJ, Singh M, Ho BC, Hian YE

Southeast Asian J. Trop. Med. Public Health, 1975 Jun;6(2):241-6.
PMID: 1166352

Seven of the 18 species of lowland forest terrestrial and semi-arboreal murids were found naturally infected with Breinlia booliati. Of these, two species, Rattus sabanus and R. cremoriventer, were found to be the most preferred hosts. None of the murids from the highland, field or human-inhabited areas was infected. This could have been due more to the greater scarcity of the vectors in these habitats than to the susceptibility of the hosts. The absence of this parasite in the squirrels examined may be attributed either to host specificity or to the normal activity cycles or vertical stratification of the vectors, separating them in space and/or time from the squirrels. The pattern of dispersion of the parasite is influenced by the wide distribution of suitable hosts, and the hypothesis that the parasite is of forest origin is discussed.

Matched MeSH terms: Ecology
Cholera in the Kedah River area

Chen PC

Med J Malaya, 1970 Jun;24(4):247-56.
PMID: 4248344
Matched MeSH terms: Ecology
[The distribution of Opistorchis and Paragonimus in Malaya and possible sources of infection of man with these parasites]

Rohde K

Z Tropenmed Parasitol, 1967 Jul;18(2):152-61.
PMID: 5628712
Matched MeSH terms: Ecology
A survey of bat ectoparasites in West Malaysia

Beck AJ

J Med Entomol, 1971 Jul 30;8(2):147-52.
PMID: 5157835
Matched MeSH terms: Ecology
Fulltext Cryptic diversity: Two morphologically similar species of invasive apple snail in Peninsular Malaysia

Rama Rao S, Liew TS, Yow YY, Ratnayeke S

PLoS One, 2018;13(5):e0196582.
PMID: 29734361 DOI: 10.1371/journal.pone.0196582

Invasive snails in the genus Pomacea have spread across Southeast Asia including Peninsular Malaysia. Their effects on natural and agricultural wetlands are appreciable, but species-specific effects are less clear because of morphological similarity among the species. Our objective was to establish diagnostic characteristics of Pomacea species in Malaysia using genetic and morphological criteria. The mitochondrial COI gene of 52 adult snails from eight localities in Peninsular Malaysia was amplified, sequenced, and analysed to verify species and phylogenetic relationships. Shells were compared using geometric morphometric and covariance analyses. Two monophyletic taxa, P. canaliculata and P. maculata, occurred in our samples. The mean ratio of shell height: aperture height (P = 0.042) and shell height: shell width (P = 0.007) was smaller in P. maculata. P. maculata co-occurred with P. canaliculata in five localities, but samples from three localities contained only P. canaliculata. This study is the first to confirm the presence of two of the most invasive species of Pomacea in Peninsular Malaysia using a molecular technique. P. canaliculata appears to be the more widespread species. Despite statistical differences, both quantitative and qualitative morphological characteristics demonstrated much interspecific overlap and intraspecific variability; thus, shell morphology alone cannot reliably verify species identity. Molecular techniques for distinguishing between these two highly invasive Pomacea species are needed to understand their specific ecological niches and to develop effective protocols for their management.

Matched MeSH terms: Ecology
Fulltext Spatio-temporal ecology of sympatric felids on Borneo. Evidence for resource partitioning?

Hearn AJ, Cushman SA, Ross J, Goossens B, Hunter LTB, Macdonald DW

PLoS One, 2018;13(7):e0200828.
PMID: 30028844 DOI: 10.1371/journal.pone.0200828

Niche differentiation, the partitioning of resources along one or more axes of a species' niche hyper-volume, is widely recognised as an important mechanism for sympatric species to reduce interspecific competition and predation risk, and thus facilitate co-existence. Resource partitioning may be facilitated by behavioural differentiation along three main niche dimensions: habitat, food and time. In this study, we investigate the extent to which these mechanisms can explain the coexistence of an assemblage of five sympatric felids in Borneo. Using multi-scale logistic regression, we show that Bornean felids exhibit differences in both their broad and fine-scale habitat use. We calculate temporal activity patterns and overlap between these species, and present evidence for temporal separation within this felid guild. Lastly, we conducted an all-subsets logistic regression to predict the occurrence of each felid species as a function of the co-occurrence of a large number of other species and showed that Bornean felids co-occurred with a range of other species, some of which could be candidate prey. Our study reveals apparent resource partitioning within the Bornean felid assemblage, operating along all three niche dimension axes. These results provide new insights into the ecology of these species and the broader community in which they live and also provide important information for conservation planning for this guild of predators.

Matched MeSH terms: Ecology
Application of enrichment factor, geoaccumulation index, and ecological risk index in assessing the elemental pollution status of surface sediments

Looi LJ, Aris AZ, Yusoff FM, Isa NM, Haris H

Environ Geochem Health, 2019 Feb;41(1):27-42.
PMID: 29982907 DOI: 10.1007/s10653-018-0149-1

Sediment can accumulate trace elements in the environment. This study profiled the magnitude of As, Ba, Cd, Co, Cu, Cr, Ni, Pb, Se, and Zn pollution in surface sediments of the west coast of Peninsular Malaysia. Trace elements were digested using aqua regia and were analyzed using the inductively coupled plasma-mass spectrometry. The extent of elemental pollution was evaluated using with the enrichment factor (EF) and geoaccumulation index (Igeo). This study found that the elemental distribution in the sediment in descending order was Zn > Ba > Cr > Pb > Cu > As > Ni > Co > Se > Cd. Zn concentrations in all samples were below the interim sediment quality guideline (ISQG) (124 mg/kg). In contrast, Cd concentrations (2.34 ± 0.01 mg/kg) at Station 31 (Merlimau) exceeded the ISQG (0.70 mg/kg), and the concentrations of As in the samples from Station 9 (Tanjung Dawai) exceeded the probable effect level (41.60 mg/kg). The Igeo and EF revealed that Station 9 and Station 31 were extremely enriched with Se and Cd, respectively. All stations posed low ecological risk, except Station 31, which had moderate ecological risk. The outputs from this study are expected to provide the background levels of pollutants and help develop regional sediment quality guideline values. This study is also important in aiding relevant authorities to set priorities for resources management and policy implementation.

Matched MeSH terms: Ecology
Fulltext Garcinia subelliptica Merr. (Fukugi): A multipurpose coastal tree with promising medicinal properties

Inoue T, Kainuma M, Baba K, Oshiro N, Kimura N, Chan EW

J Intercult Ethnopharmacol, 2017 Jan 3;6(1):121-127.
PMID: 28163970 DOI: 10.5455/jice.20161229060034

In this short review, the current knowledge on the botany, ecology, uses, and medicinal properties of the multipurpose Garcinia subelliptica (Fukugi) is updated. As yet, there are no reviews on this indigenous and heritage coastal tree species of the Ryukyu Islands in Japan, which has ethnocultural, ecological, and pharmacological significance. Planted by the Okinawan people some 300 years ago, Fukugi trees serve as windbreaks and accord protection against the destructive typhoons. The species has become a popular ornamental tree, and its bark has been used for dyeing fabrics. It forms part of the food chain for mammals and insects and serves as nesting sites for birds. Endowed with bioactive compounds of benzophenones, xanthones, biflavonoids, and triterpenoids, G. subelliptica possesses anticancer, anti-inflammatory, anti-tyrosinase, trypanocidal, antibacterial, DNA topoisomerase inhibitory, DNA strand scission, choline acetyltransferase enhancing, hypoxia-inducible factor-1 inhibitory, and antiandrogenic activities. Fukugetin and fukugiside are two novel biflavonoids named after the species. The chemical constituents of Fukugi fruits when compared with those of mangosteen yielded interesting contrasts.

Matched MeSH terms: Ecology
Evaluation of heavy metals and environmental risk assessment in the Mangrove Forest of Kuala Selangor estuary, Malaysia

ELTurk M, Abdullah R, Rozainah MZ, Abu Bakar NK

Mar Pollut Bull, 2018 Nov;136:1-9.
PMID: 30509789 DOI: 10.1016/j.marpolbul.2018.08.063

This study was carried out to evaluate the distribution, enrichment and ecological risk of heavy metals (arsenic (As), zinc (Zn), manganese (Mn), copper (Cu) and lead (Pb)) concentration in Kuala Selangor estuary at the Kuala Selangor Nature Park. The results suggested that As and Pb in sediment were as high as the background value, suggesting the presence of anthropogenic contamination. The risk assessment of sediment Igeo, CD, and PERI, on the other hand, showed low risk of heavy metals in Kuala Selangor estuary. Meanwhile, risk assessment code (RAC) results showed that Mn, As and Zn presented medium to high level of environmental risk. The translocation factor and bioaccumulation factors of heavy metal concentration by mangrove vegetation showed a variety of trends, which indicates the different partitioning and uptake ability of heavy metal in the tissues of different mangrove species. Therefore, underscores the importance of preserving the high diversity of mangroves at securing the health and productivity of the coastal region. These results may play a critical role in facilitating decision makers in managing the sustainability of mangrove forests.

Matched MeSH terms: Ecology
Fulltext Socio-epidemiological and land cover risk factors for melioidosis in Kedah, Northern Malaysia

Abu Hassan MR, Aziz N, Ismail N, Shafie Z, Mayala B, Donohue RE, et al.

PLoS Negl Trop Dis, 2019 03;13(3):e0007243.
PMID: 30883550 DOI: 10.1371/journal.pntd.0007243

BACKGROUND: Melioidosis, a fatal infectious disease caused by Burkholderia pseudomallei, is increasingly diagnosed in tropical regions. However, data on risk factors and the geographic epidemiology of the disease are still limited. Previous studies have also largely been based on the analysis of case series data. Here, we undertook a more definitive hospital-based matched case-control study coupled with spatial analysis to identify demographic, socioeconomic and landscape risk factors for bacteremic melioidosis in the Kedah region of northern Malaysia.
METHODOLOGY/PRINCIPAL FINDINGS: We obtained patient demographic and residential information and clinical presentation and medical history data from 254 confirmed melioidosis cases and 384 matched controls attending Hospital Sultanah Bahiyah (HSB), the main tertiary hospital of Alor Setar, the capital city of Kedah, during the period between 2005 and 2011. Crude and adjusted odds ratios employing conditional logistic regression analysis were used to assess if melioidosis in this region is related to risk factors connected with socio-demographics, various behavioural characteristics, and co-occurring diseases. Spatial clusters of cases were determined using a continuous Poisson model as deployed in SaTScan. A land cover map in conjunction with mapped case data was used to determine disease-land type associations using the Fisher's exact test deploying simulated p-values. Crude and adjusted odds ratios indicate that melioidosis in this region is related to gender (males), race, occupation (farming) and co-occurring chronic diseases, particularly diabetes. Spatial analyses of disease incidence, however, showed that disease risk and geographic clustering of cases are related strongly to land cover types, with risk of disease increasing non-linearly with the degree of human modification of the natural ecosystem.
CONCLUSIONS/SIGNIFICANCE: These findings indicate that melioidosis represents a complex socio-ecological public health problem in Kedah, and that its control requires an understanding and modification of the coupled human and natural variables that govern disease transmission in endemic communities.

Matched MeSH terms: Ecology
Diversity of pollination ecology in the Schismatoglottis Calyptrata Complex Clade (Araceae)

Hoe YC, Gibernau M, Wong SY

Plant Biol (Stuttg), 2018 May;20(3):563-578.
PMID: 29316090 DOI: 10.1111/plb.12687

Field studies integrating pollination investigations with an assessment of floral scent composition and thermogenesis in tropical aroids are rather few. Thus, this study aimed to investigate the pollination biology of nine species belonging to Schismatoglottis Calyptrata Complex Clade. The flowering mechanism, visiting insect activities, reproductive system, thermogenesis and floral scent composition were examined. Anthesis for all species started at dawn and lasted 25-29 h. Colocasiomyia (Diptera, Drosophilidae) are considered the main pollinators for all the investigated species. Cycreon (Coleoptera, Hydrophilidae) are considered secondary pollinators as they are only present in seven of the nine host plants, despite the fact that they are the most effective pollen carrier, carrying up to 15 times more pollen grains than Colocasiomyia flies. However, the number of Colocasiomyia individuals was six times higher than Cycreon beetles. Chaloenus (Chrysomelidae, Galeuricinae) appeared to be an inadvertent pollinator. Atheta (Coleoptera, Staphylinidae) is considered a floral visitor in most investigated species of the Calyptrata Complex Clade in Sarawak, but a possible pollinator in S. muluensis. Chironomidae midges and pteromalid wasps are considered visitors in S. calyptrata. Thermogenesis in a biphasic pattern was observed in inflorescences of S. adducta, S. calyptrata, S. giamensis, S. pseudoniahensis and S. roh. The first peak occurred during pistillate anthesis; the second peak during staminate anthesis. Inflorescences of all investigated species of Calyptrata Complex Clade emitted four types of ester compound, with methyl ester-3-methyl-3-butenoic acid as a single major VOC (volatile organic compound). The appendix, pistillate zone, staminate zone and spathe emitted all these compounds. A mixed fly-beetle pollination system is considered an ancestral trait in the Calyptrata Complex Clade, persisting in Sarawak taxa, whereas the marked reduction of interpistillar staminodes in taxa from Peninsular Malaysia and especially, Ambon, Indonesia, is probably linked to a shift in these taxa to a fly-pollinated system.

Matched MeSH terms: Ecology
Fulltext The effects of temperature and shading on mortality and development rates of Aedes aegypti (Diptera: Culicidae)

Sukiato F, Wasserman RJ, Foo SC, Wilson RF, Cuthbert RN

J Vector Ecol, 2019 12;44(2):264-270.
PMID: 31729799 DOI: 10.1111/jvec.12358

Urbanization has caused an increase in favorable habitats for Aedes aegypti (Diptera: Culicidae), given their ability to reproduce in small and often non-degradable artificial water-containers. While much work has been done on Ae. aegypti biology and ecology in urban landscapes, the role of shading on immature stages as an independent factor from temperature, and any possible interactions between these factors, remains unexamined. We assessed how temperature and shading affected egg hatch-rate, larval/pupal mortality, and larval development to adult stage under different factorial temperature (28; 31; 34; 37; 40° C) and shade (0%, 3,100 lux; 40%, 1,860 lux; 75%, 775 lux; 100%, 0 lux) regimes. Hatch-rate was significantly lower at 37° C (57 %), and no eggs hatched at 40° C. There was no significant effect caused by shading on hatchability. Larval and pupal mortality at 37° C was significantly higher (35%) compared to lower temperature groups, while the effects of shading were emergent at low temperatures. Developmental times from hatching to adult emergence were significantly reduced with increasing temperatures and with greater light exposures. The eco-physiological response of Ae. aegypti larvae to temperature and light regimes suggest a photosensitivity previously unstudied in this species.

Matched MeSH terms: Ecology
Distribution, relative abundance, food habits, and parasite patterns of giant rats (Rattus) in West Malaysia

Lim BL

J Mammal, 1970 Nov;51(4):730-40.
PMID: 5530310
Matched MeSH terms: Ecology
Studies on the nematode parasites of Malaysian rodents. I. The Rhabdiasidea, Trichuridea and Oxyuridea

Ow-Yang CK

J Helminthol, 1971;45(2):93-109.
PMID: 5123705
Matched MeSH terms: Ecology
Fulltext Interdisciplinary approaches to understanding disease emergence: the past, present, and future drivers of Nipah virus emergence

Daszak P, Zambrana-Torrelio C, Bogich TL, Fernandez M, Epstein JH, Murray KA, et al.

Proc Natl Acad Sci U S A, 2013 Feb 26;110 Suppl 1:3681-8.
PMID: 22936052 DOI: 10.1073/pnas.1201243109

Emerging infectious diseases (EIDs) pose a significant threat to human health, economic stability, and biodiversity. Despite this, the mechanisms underlying disease emergence are still not fully understood, and control measures rely heavily on mitigating the impact of EIDs after they have emerged. Here, we highlight the emergence of a zoonotic Henipavirus, Nipah virus, to demonstrate the interdisciplinary and macroecological approaches necessary to understand EID emergence. Previous work suggests that Nipah virus emerged due to the interaction of the wildlife reservoir (Pteropus spp. fruit bats) with intensively managed livestock. The emergence of this and other henipaviruses involves interactions among a suite of anthropogenic environmental changes, socioeconomic factors, and changes in demography that overlay and interact with the distribution of these pathogens in their wildlife reservoirs. Here, we demonstrate how ecological niche modeling may be used to investigate the potential role of a changing climate on the future risk for Henipavirus emergence. We show that the distribution of Henipavirus reservoirs, and therefore henipaviruses, will likely change under climate change scenarios, a fundamental precondition for disease emergence in humans. We assess the variation among climate models to estimate where Henipavirus host distribution is most likely to expand, contract, or remain stable, presenting new risks for human health. We conclude that there is substantial potential to use this modeling framework to explore the distribution of wildlife hosts under a changing climate. These approaches may directly inform current and future management and surveillance strategies aiming to improve pathogen detection and, ultimately, reduce emergence risk.

Matched MeSH terms: Ecology
Breaking open a closed system

Cyranoski D

Nature, 2005 Aug 11;436(7052):884-5.
PMID: 16136648
Matched MeSH terms: Ecology
Fulltext Bionomics of important mosquito vectors in Malaysia

Vythilingam I, Chiang GL, Lee HL, Singh KI

Southeast Asian J. Trop. Med. Public Health, 1992 Dec;23(4):587-603.
PMID: 1363679
Matched MeSH terms: Ecology

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