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Fulltext Paternity analysis-based inference of pollen dispersal patterns, male fecundity variation, and influence of flowering tree density and general flowering magnitude in two dipterocarp species

Tani N, Tsumura Y, Kado T, Taguchi Y, Lee SL, Muhammad N, et al.

Ann Bot, 2009 Dec;104(7):1421-34.
PMID: 19808773 DOI: 10.1093/aob/mcp252

BACKGROUND AND AIMS: Knowledge of pollen dispersal patterns and variation of fecundity is essential to understanding plant evolutionary processes and to formulating strategies to conserve forest genetic resources. Nevertheless, the pollen dispersal pattern of dipterocarp, main canopy tree species in palaeo-tropical forest remains unclear, and flowering intensity variation in the field suggests heterogeneity of fecundity.
METHODS: Pollen dispersal patterns and male fecundity variation of Shorea leprosula and Shorea parvifolia ssp. parvifolia on Peninsular Malaysian were investigated during two general flowering seasons (2001 and 2002), using a neighbourhood model modified by including terms accounting for variation in male fecundity among individual trees to express heterogeneity in flowering.
KEY RESULTS: The pollen dispersal patterns of the two dipterocarp species were affected by differences in conspecific tree flowering density, and reductions in conspecific tree flowering density led to an increased selfing rate. Active pollen dispersal and a larger number of effective paternal parents were observed for both species in the season of greater magnitude of general flowering (2002).
CONCLUSIONS: The magnitude of general flowering, male fecundity variation, and distance between pollen donors and mother trees should be taken into account when attempting to predict the effects of management practices on the self-fertilization and genetic structure of key tree species in tropical forest, and also the sustainability of possible management strategies, especially selective logging regimes.

Matched MeSH terms: Population Density
Transformation of nitrogen dioxide into ozone and prediction of ozone concentrations using multiple linear regression techniques

Ghazali NA, Ramli NA, Yahaya AS, Yusof NF, Sansuddin N, Al Madhoun WA

Environ Monit Assess, 2010 Jun;165(1-4):475-89.
PMID: 19440846 DOI: 10.1007/s10661-009-0960-3

Analysis and forecasting of air quality parameters are important topics of atmospheric and environmental research today due to the health impact caused by air pollution. This study examines transformation of nitrogen dioxide (NO(2)) into ozone (O(3)) at urban environment using time series plot. Data on the concentration of environmental pollutants and meteorological variables were employed to predict the concentration of O(3) in the atmosphere. Possibility of employing multiple linear regression models as a tool for prediction of O(3) concentration was tested. Results indicated that the presence of NO(2) and sunshine influence the concentration of O(3) in Malaysia. The influence of the previous hour ozone on the next hour concentrations was also demonstrated.

Matched MeSH terms: Urban Population
Molecular and morphological approaches in discrimination of endangered Probarbus jullieni of Malaysia and Thailand stocks

Bhassu S, Abd Rashid Z

Genetika, 2009 Sep;45(9):1244-9.
PMID: 19824545

The population structure of Probarbus jullieni from Malaysia and Thailand stocks was based on seven microsatellite primers and truss network measurements. Truss morphometric measurements were made on Temoleh, Probarbus jullieni to demonstrate the degree of speciation that can be induced by both biotic and abiotic conditions and contribute to the definition of different stocks of Probarbus sp. At the momment no relevant information on stock definition has been produced recently concerning Probarbus spp., which is now in IUCN threatened red list. We also summarize the possible discriminant morphological characteristics that shows differentiation between Malaysia and Thailand stocks. We also compare the levels of morphology and genetic differences for Malaysian stocks throughout one year of sampling to determine whether sampling season and possible sexual dimorphism can be detected in this fishes. A total of 25 different alleles were found across the two populations by the seven microsatellites, of which 21 and 19 alleles were detected in Pahang, Malaysia and Thailand, respectively At the population level, the mean number of alleles of Pahang (3.4991) per locus was higher than that (3.1665) of Thailand. From both molecular and morphometric measurements showed that there were two distinct populations. However the differences between these two populations showed that they belong to the same species with least degree of separation

Matched MeSH terms: Genetics, Population
Experimental evidence for the effects of dung beetle functional group richness and composition on ecosystem function in a tropical forest

Slade EM, Mann DJ, Villanueva JF, Lewis OT

J Anim Ecol, 2007 Nov;76(6):1094-104.
PMID: 17922706

Much of the literature on the relationship between species richness or functional group richness and measures of ecosystem function focuses on a restricted set of ecosystem function measures and taxonomic groups. Few such studies have been carried out under realistic levels of diversity in the field, particularly in high diversity ecosystems such as tropical forests. We used exclusion experiments to study the effects of dung beetle functional group richness and composition on two interlinked and functionally important ecological processes, dung removal and secondary seed dispersal, in evergreen tropical forest in Sabah, Malaysian Borneo. Overall, both dung and seed removal increased with dung beetle functional group richness. However, levels of ecosystem functioning were idiosyncratic depending on the identity of the functional groups present, indicating an important role for functional group composition. There was no evidence for interference or competition among functional groups. We found strong evidence for overyielding and transgressive overyielding, suggesting complementarity or facilitation among functional groups. Not all mixtures showed transgressive overyielding, so that complementarity was restricted to particular functional group combinations. Beetles in a single functional group (large nocturnal tunnellers) had a disproportionate influence on measures of ecosystem function: in their absence dung removal is reduced by approximately 75%. However, a full complement of functional groups is required to maximize ecosystem functioning. This study highlights the importance of both functional group identity and species composition in determining the ecosystem consequences of extinctions or altered patterns in the relative abundance of species.

Matched MeSH terms: Population Dynamics
Effects of flowering tree density on the mating system and gene flow in Shorea leprosula (Dipterocarpaceae) in Peninsular Malaysia

Fukue Y, Kado T, Lee SL, Ng KK, Muhammad N, Tsumura Y

J Plant Res, 2007 May;120(3):413-20.
PMID: 17387430

Pristine tropical rainforests in Southeast Asia have rich species diversity and are important habitats for many plant species. However, the extent of these forests has declined in recent decades and they have become fragmented due to human activities. These developments may reduce the genetic diversity of species within them and, consequently, the species' ability to adapt to environmental changes. Our objective in the study presented here was to clarify the effect of tree density on the genetic diversity and gene flow patterns of Shorea leprosula Miq. populations in Peninsular Malaysia. For this purpose, we related genetic diversity and pollen flow parameters of seedling populations in study plots to the density of mature trees in their vicinity. The results show that gene diversity and allelic richness were not significantly correlated to the mature tree density. However, the number of rare alleles among the seedlings and the selfing rates of the mother trees were negatively correlated with the density of the adult trees. Furthermore, in a population with high mature tree density pollination distances were frequently <200 m, but in populations with low adult tree density the distances were longer. These findings suggest that the density of flowering trees affects selfing rates, gene flow and, thus, the genetic diversity of S. leprosula populations. We also found an individual S. leprosula tree with a unique reproductive system, probably apomictic, mating system.

Matched MeSH terms: Population Density
Fulltext Dengue fever in Malaysia: time for review?

Kumarasamy V

Med J Malaysia, 2006 Mar;61(1):1-3.
PMID: 16708726

Dengue is the most important arthropod borne viral disease of public health significance. Compared to nine reporting countries in the 1950's, today the geographical distribution includes more than 100 countries world wide. The WHO estimates that more than 2.5 billion people are at risk of dengue infections, with 50 million cases occurring annually with 22,000 deaths'. The dengue virus is an enveloped single stranded RNA of the family Flaviridae. There are four serotypes which share genetic and antigenic features but infection with the one serotype does not provide long-term protection against other serotypes. The principal vector is the day biting Aedes aegypti which typically breeds in clean stagnant water in a wide variety of sites including man made containers in the domestic and peridomestic urban environment

Matched MeSH terms: Population Surveillance
Suburban sprawl in the developing world: duplicating past mistakes? The case of Kuala Lumpur, Malaysia

Loh LC, Brieger WB

Int Q Community Health Educ, 2013;34(2):199-211.
PMID: 24928611 DOI: 10.2190/IQ.34.2.g

Newly affluent developing world cities increasingly adopt the same unfortunate low-density suburban paradigm that shaped cities in the industrialized world. Identified by a World Bank report as a "mini-Los Angeles," Kuala Lumpur is a sentinel example of the results of unrestrained sprawl in the developing world. Factors driving sprawl included government policies favoring foreign investment, "mega-projects," and domestic automobile production; fragmented governance structures allowing federal and state government influence on local planning; increasing middle-class affluence; an oligopoly of local developers; and haphazard municipal zoning and transport planning. The city's present form contributes to Malaysia's dual burden of disease, with inner-city shantytown dwellers facing communicable disease and malnutrition while suburban citizens experience increasing chronic disease, injury, and mental health issues. Despite growing awareness in city plans targeted toward higher density development, Kuala Lumpur presents a warning to other emerging economies of the financial, societal, and population health costs imposed by quickly-built suburban sprawl.
Publication year: 2013-2014

Matched MeSH terms: Population Density
Variation in pollen dispersal between years with different pollination conditions in a tropical emergent tree

Kenta T, Isagi Y, Nakagawa M, Yamashita M, Nakashizuka T

Mol Ecol, 2004 Nov;13(11):3575-84.
PMID: 15488013

We examined differences in pollen dispersal efficiency between 2 years in terms of both spatial dispersal range and genetic relatedness of pollen in a tropical emergent tree, Dipterocarpus tempehes. The species was pollinated by the giant honeybee (Apis dorsata) in a year of intensive community-level mass-flowering or general flowering (1996), but by several species of moths in a year of less-intensive general flowering (1998). We carried out paternity analysis based on six DNA microsatellite markers on a total of 277 mature trees forming four spatially distinct subpopulations in a 70 ha area, and 147 and 188 2-year-old seedlings originating from seeds produced in 1996 and 1998 (cohorts 96 and 98, respectively). Outcrossing rates (0.93 and 0.96 for cohorts 96 and 98, respectively) did not differ between years. Mean dispersal distances (222 and 192 m) were not significantly different between the 2 years but marginally more biased to long distance in 1996. The mean relatedness among cross-pollinated seedlings sharing the same mothers in cohort 96 was lower than that in cohort 98. This can be attributed to the two facts that the proportion of intersubpopulations pollen flow among cross-pollination events was marginally higher in cohort 96 (44%) than in cohort 98 (33%), and that mature trees within the same subpopulations are genetically more related to each other than those between different subpopulations. We conclude that D. tempehes maintained effective pollen dispersal in terms of outcrossing rate and pollen dispersal distance in spite of the large difference in foraging characteristics between two types of pollinators. In terms of pollen relatedness, however, a slight difference was suggested between years in the level of biparental inbreeding.

Matched MeSH terms: Genetics, Population
Fulltext Interspecies interactions are an integral determinant of microbial community dynamics

Aziz FA, Suzuki K, Ohtaki A, Sagegami K, Hirai H, Seno J, et al.

Front Microbiol, 2015;6:1148.
PMID: 26539177 DOI: 10.3389/fmicb.2015.01148

This study investigated the factors that determine the dynamics of bacterial communities in a complex system using multidisciplinary methods. Since natural and engineered microbial ecosystems are too complex to study, six types of synthetic microbial ecosystems (SMEs) were constructed under chemostat conditions with phenol as the sole carbon and energy source. Two to four phenol-degrading, phylogenetically and physiologically different bacterial strains were used in each SME. Phylogeny was based on the nucleotide sequence of 16S rRNA genes, while physiologic traits were based on kinetic and growth parameters on phenol. Two indices, J parameter and "interspecies interaction," were compared to predict which strain would become dominant in an SME. The J parameter was calculated from kinetic and growth parameters. On the other hand, "interspecies interaction," a new index proposed in this study, was evaluated by measuring the specific growth activity, which was determined on the basis of relative growth of a strain with or without the supernatant prepared from other bacterial cultures. Population densities of strains used in SMEs were enumerated by real-time quantitative PCR (qPCR) targeting the gene encoding the large subunit of phenol hydroxylase and were compared to predictions made from J parameter and interspecies interaction calculations. In 4 of 6 SEMs tested the final dominant strain shown by real-time qPCR analyses coincided with the strain predicted by both the J parameter and the interspecies interaction. However, in SMEII-2 and SMEII-3 the final dominant Variovorax strains coincided with prediction of the interspecies interaction but not the J parameter. These results demonstrate that the effects of interspecies interactions within microbial communities contribute to determining the dynamics of the microbial ecosystem.

Matched MeSH terms: Population Density
Reference ranges of handgrip strength from 125,462 healthy adults in 21 countries: a prospective urban rural epidemiologic (PURE) study

Leong DP, Teo KK, Rangarajan S, Kutty VR, Lanas F, Hui C, et al.

J Cachexia Sarcopenia Muscle, 2016 12;7(5):535-546.
PMID: 27104109

BACKGROUND: The measurement of handgrip strength (HGS) has prognostic value with respect to all-cause mortality, cardiovascular mortality and cardiovascular disease, and is an important part of the evaluation of frailty. Published reference ranges for HGS are mostly derived from Caucasian populations in high-income countries. There is a paucity of information on normative HGS values in non-Caucasian populations from low- or middle-income countries. The objective of this study was to develop reference HGS ranges for healthy adults from a broad range of ethnicities and socioeconomically diverse geographic regions.
METHODS: HGS was measured using a Jamar dynamometer in 125,462 healthy adults aged 35-70 years from 21 countries in the Prospective Urban Rural Epidemiology (PURE) study.
RESULTS: HGS values differed among individuals from different geographic regions. HGS values were highest among those from Europe/North America, lowest among those from South Asia, South East Asia and Africa, and intermediate among those from China, South America, and the Middle East. Reference ranges stratified by geographic region, age, and sex are presented. These ranges varied from a median (25th-75th percentile) 50 kg (43-56 kg) in men <40 years from Europe/North America to 18 kg (14-20 kg) in women >60 years from South East Asia. Reference ranges by ethnicity and body-mass index are also reported.
CONCLUSIONS: Individual HGS measurements should be interpreted using region/ethnic-specific reference ranges.

Matched MeSH terms: Population Surveillance
Are speech-evoked auditory brainstem response (speech-ABR) outcomes influenced by ethnicity?

Zakaria MN, Jalaei B, Aw CL, Sidek D

Neurol Sci, 2016 Jun;37(6):943-8.
PMID: 26921173 DOI: 10.1007/s10072-016-2522-0

Due to its objective nature, auditory brainstem response (ABR) evoked by complex stimuli has been gaining attention lately. The present study aimed to compare the speech-evoked auditory brainstem response (speech-ABR) results between two ethnic groups: Malay and Chinese. In addition, it was also of interest to compare the speech-ABR outcomes obtained from the present study with the published Caucasian data. Thirty healthy male adults (15 Malay and 15 Chinese) were enrolled in this comparative study. Speech syllable/da/presented at 80 dBnHL was used to record speech-ABR waveforms from the right ear of each subject. Amplitudes and latencies of speech-ABR peaks (V, A, C, D, E, F and O), as well as composite onset measures (V/A duration, V/A amplitude and V/A slope) were computed and analyzed. When the two ethnic groups were compared, all speech-ABR results were not statistically different from each other (p > 0.05). When the data from the present study were compared with the published Caucasian data, most of the statistical analyses were significant (p

Matched MeSH terms: Continental Population Groups
Distribution of cytokine gene polymorphisms in six Orang Asli subgroups in Peninsular Malaysia

Norhalifah HK, Syafawati WU, Che Mat NF, Chambers GK, Edinur HA

Hum Immunol, 2016 Apr;77(4):338-9.
PMID: 26820937 DOI: 10.1016/j.humimm.2016.01.015

Cytokines are involved in immune responses and the pathogenesis of various diseases. Allelic variations within the genes coding for various ∼30kDa cytokine protein/glycoproteins have been reported for many populations and have been the subjects of many ancestry and health analyses. In this study, we typed 22 single nucleotide polymorphisms (SNPs) in 13 cytokine genes of 165 Orang Asli individuals by using sequence specific primer-polymerase chain reaction (SSP-PCR) assay. The volunteers came from all across the Peninsular of Malaysia and belong to six Orang Asli subgroups; Batek, Kensiu, Lanoh, Che Wong, Semai and Orang Kanaq. Here we report our general findings and original genotype data and their associated analyses (Hardy-Weinberg proportions, estimation of allele and haplotype frequencies) can be found in the supplementary files and will be held at Allele Frequency Net Database (AFND).

Matched MeSH terms: Population Groups
Indo-Pacific Humpback Dolphins in Borneo: A Review of Current Knowledge with Emphasis on Sarawak

Minton G, Zulkifli Poh AN, Peter C, Porter L, Kreb D

Adv. Mar. Biol., 2016;73:141-56.
PMID: 26790891 DOI: 10.1016/bs.amb.2015.07.003

Indo-Pacific humpback dolphins (Sousa chinensis) are documented from various locations along Borneo's coast, including three sites in Sarawak, Malaysia, three sites in Sabah, Malaysia, three locations in Kalimantan, Indonesia and the limited coastal waters of the Sultanate of Brunei. Observations in all these areas indicate a similar external morphology, which seems to fall somewhere between that documented for Chinese populations known as S. chinensis, and that of Sousa sahulensis in Australia and Papua New Guinea. Sightings occur in shallow nearshore waters, often near estuaries and river mouths, and associations with Irrawaddy dolphins (Orcaella brevirostris) are frequently documented. Population estimates exist for only two locations and sightings information throughout Borneo indicates that frequency of occurrence is rare and group size is usually small. Threats from fisheries by-catch and coastal development are present in many locations and there are concerns over the ability of these small and fragmented populations to survive. The conservation and taxonomic status of humpback dolphins in Borneo remain unclear, and there are intriguing questions as to where these populations fit in our evolving understanding of the taxonomy of the genus.

Matched MeSH terms: Population Dynamics
Fulltext From Third World to Fourth. Third WONCA World Conference on Rural Health in Kuching, Malaysia; Fourth in Calgary

Topps D, Rourke J

Can Fam Physician, 2000 Oct;46:2065.
PMID: 11072589
Matched MeSH terms: Continental Population Groups
Predictors of recurrent abdominal pain among 9 to 15-year-old urban school-children in Malaysia

Boey CC, Goh KL

Acta Paediatr, 2001 Mar;90(3):353-5.
PMID: 11332181

A cross-sectional survey of school-children aged from 9 to 15 y was performed in the city of Petaling Jaya to look for predictors of recurrent abdominal pain. A sample of 1488 children was randomly chosen, of whom 143 (9.6%) had recurrent abdominal pain according to Apley's criteria.

Matched MeSH terms: Urban Population
Changes in abundance and behaviour of vector mosquitoes induced by land use during the development of an oil palm plantation in Sarawak

Chang MS, Hii J, Buttner P, Mansoor F

Trans R Soc Trop Med Hyg, 1997 7 1;91(4):382-6.
PMID: 9373626

Surveys were conducted of adult and immature mosquitoes in an area undergoing oil palm development in north Sarawak. Point prevalence data from 2 sites were collected annually, coinciding with annual phases of forest clearing, burning/cultivation, and maintenance. Major habitat perturbation during the forest/clearing transition shifted the major mosquito faunal equilibrium in terms of species composition, relative density and occurrence. Analyses of variance showed that the mean numbers of 4 species of Anopheles decreased significantly after forest clearing. Relative densities of immature stages decreased after forest clearing, but A. letifer and Culex tritaeniorhynchus remained relatively unchanged after the second year. Comparisons with the pre-development forest stage showed that the reductions in person-biting rates, adult survival and combined entomological inoculation rates (EIR) of A. donaldi and A. letifer decreased the risk of malaria transmission by 90% over the 4 years period. Concomitant reductions in EIR and annual malaria incidence were also correlated. This study highlighted the 'law of unintended consequences', since 2 contrasting effects were observed: reduction of malaria vectors but concomitant increase of dengue vectors.

Matched MeSH terms: Population Density
A mark-release-recapture experiment with Anopheles lesteri paraliae in northwest Peninsular Malaysia

Jaal Z, MacDonald WW

Ann Trop Med Parasitol, 1992 Aug;86(4):419-24.
PMID: 1463364

In a coastal village in northwest Malaysia, 3231 fed Anopheles females of eight to 10 species were collected, marked with fluorescent dust, and released on three consecutive nights. In collections made on the 10 nights after the first release, 58 mosquitoes of three species, An. lesteri paraliae, An. subpictus and An. vagus, were recaptured; the recapture rates were 3.42%, 1.19% and 0.97%, respectively. The data for An. subpictus and An. vagus were insufficient for further analysis. Those for An. l. paraliae were plotted against time of recapture and, from the regression coefficient, an estimate of 0.68 was obtained for the daily survival rate. An independent estimate based on the parous rate during the previous year was 0.55. The temporal distribution of the recaptures strongly suggested a gonotrophic cycle and oviposition cycle of two days.

Matched MeSH terms: Population Dynamics
Growth pattern of urban Malaysian infants

Hashim Z

J Trop Pediatr, 1992 Aug;38(4):204-5.
PMID: 1527822
Matched MeSH terms: Urban Population
A comparison of interalar width and intercanine distance in Malay males and females

Dharap AS, Tanuseputro H

Anthropol Anz, 1997 Mar;55(1):63-8.
PMID: 9161682

The interalar width of the nose and the intercanine distance were measured in 266 Malay subjects (111 males and 155 females) randomly selected from the students of the School of Medical Sciences. University Sains Malaysia in Kota Bharu, Malaysia. The mean interalar width of the nose in male subjects was 39.8 +/- 2.3 mm (range 34-45 mm) and in female subjects 36.2 mm +/- 2.2 mm (range 30-41 mm). There is a statistically significant difference (t = 12.9: p < 0.05) in the nasal width between male and female Malay subjects. This agrees with the findings of other similar studies that males have wider noses than females. The mean maxillary intercanine distance in male subjects was 36.7 = 2.6 mm (range 30-42 mm) and in female subjects 36.2 = 2.3 mm (range 30-42 mm). The anterior maxillary arch is significantly wider in Malay subjects compared to Chinese from Singapore (Keng 1986) as p < 0.05 and to Caucasians (Sawiris 1977) as p < 0.05. There is a significant correlation (r = 0.312; p < 0.05) between the nasal width and the intercanine distance in female subjects but not in male subjects.

Matched MeSH terms: Genetics, Population
The examination of skeletal remains

Sarvesvaran R, Knight BH

Malays J Pathol, 1994 Dec;16(2):117-26.
PMID: 9053560

The finding of skeletal remains is a common happening and the forensic pathologist is frequently called upon to examine the remains. It is theoretically much better for the pathologist to examine the bones at the site before they are disturbed, but this rarely happens, the bones being recovered by the public, workmen or police and brought in a jumbled condition to the pathologist. Using a systematic process of elimination such as that suggested in this paper, the maximum information can be obtained. Even so, it is common for the bones never to be identified and even the length of time the person has been dead remains unknown, due to lack of corroborative information. However, only by repeated and careful examination of a number of skeletal remains, can the pathologist hope to gain any experience. Probably the most important thing to bear in mind is the danger of being too dogmatic, especially about the date of the remains and not to mislead the investigating authorities by over-optimistic opinions.

Matched MeSH terms: Continental Population Groups

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