Displaying publications 141 - 160 of 317 in total

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  1. Husin MZ, Rajpar MN
    J Environ Biol, 2015 Jan;36 Spec No:121-7.
    PMID: 26591891
    The effects of logging and recovery process on avian richness and diversity was compared in recently logged and thirty year post-harvested hill dipterocarp tropical rainforest, using mist-netting method. Atotal of 803 bird individuals representing 86 bird species and 29 families (i.e., 37.90% from recently logged forest and 62.10% from thirty year post-harvested forest) were captured from October 2010 to September, 2012. Twenty one bird species were commonly captured from both types of forests, 37 bird species were caught only in thirty year post-harvested forest and 28 bird species were caught only from recently logged forest. Arachnothera longirostra--Little Spiderhunter, Malacopteron magnum--Rufous-crowned Babbler, Alophoixus phaeocephalus -Yellow-bellied Bulbul and Meiglyptes tukki--Buff-necked Woodpecker were the most abundant four bird species in the thirty year post-harvested forest. On the contrary, seven bird species, i.e., Trichastoma rostratum - White-chested Babbler, Lacedo pulchella - Banded Kingfisher, Picus miniaceus--Banded Woodpecker, Enicurus ruficapillus - Chestnut-naped Forktail, Anthreptes simplex--Plain Sunbird, Muscicapella hodgsoni--Pygmy Blue Flycatcher and Otus rufescens--Reddish Scope Owl were considered as the rarest (i.e., each represented only 0.12%). Likewise, A. longirostra, Pycnonotus eythropthalmos - Spectacled Bulbul, P. simplex--Cream-vented Bulbul and Merops viridis--Blue-throated Bee-eater were the most dominant and Copsychus malabaricus--White-rumped Shama Eurylaimus javanicus--Banded Broadbill /xos malaccensis - Streaked Bulbul and Harpactes diardii--Diard's Trogon (each 0.12%) were the rarest bird species in recently logged forest. CAP analysis indicated that avian species in thirty year post-harvested forest were more diverse and evenly distributed than recently logged forest. However, recently logged forest was rich in bird species than thirty year post- harvested forest. The results revealed that logging and retrieval process affect bird species richness and diversity. However, bird species may respond differently from habitat to habitat, i.e., forest logging causes disturbance of some avian species while recovery process may replace the loss of vegetation and harbour a wide array of avian species richness and diversity.
    Matched MeSH terms: Population Dynamics
  2. Lawson JM, Foster SJ, Lim AC, Chong VC, Vincent AC
    J Fish Biol, 2015 Jan;86(1):1-15.
    PMID: 25307290 DOI: 10.1111/jfb.12527
    Life-history variables for three incidentally captured species of seahorse (Kellogg's seahorse Hippocampus kelloggi, the hedgehog seahorse Hippocampus spinosissimus and the three-spot seahorse Hippocampus trimaculatus) were established using specimens obtained from 33 fisheries landing sites in Peninsular Malaysia. When samples were pooled by species across the peninsula, sex ratios were not significantly different from unity, and height and mass relationships were significant for all species. For two of these species, height at physical maturity (HM ) was smaller than the height at which reproductive activity (HR ) commenced: H. spinosissimus (HM = 99·6 mm, HR = 123·2 mm) and H. trimaculatus (HM = 90·5 mm, HR = 121·8 mm). For H. kelloggi, HM could not be estimated as all individuals were physically mature, while HR = 167·4 mm. It appears that all three Hippocampus spp. were, on average, caught before reproducing; height at 50% capture (HC ) was ≥HM but ≤HR . The results from this study probe the effectiveness of assessment techniques for data-poor fisheries that rely heavily on estimates of length at maturity, especially if maturity is poorly defined. Findings also question the sustainability of H. trimaculatus catches in the south-west region of Peninsular Malaysia, where landed specimens had a notably smaller mean height (86·2 mm) and markedly skewed sex ratio (6% males) compared with samples from the south-east and north-west of the peninsula.
    Matched MeSH terms: Population Dynamics
  3. Mat Jaafar TNA, Taylor MI, Mohd Nor SA, Bruyn M, Carvalho GR
    J Fish Biol, 2020 Feb;96(2):337-349.
    PMID: 31721192 DOI: 10.1111/jfb.14202
    We examine genetic structuring in three commercially important species of the teleost family Carangidae from Malaysian waters: yellowtail scad Atule mate, bigeye scad Selar crumenophthalmus and yellowstripe scad Selaroides leptolepis, from the Indo-Malay Archipelago. In view of their distribution across contrasting habitats, we tested the hypothesis that pelagic species display less genetic divergence compared with demersal species, due to their potential to undertake long-distance migrations in oceanic waters. To evaluate population genetic structure, we sequenced two mitochondrial (mt)DNA [650 bp of cytochrome oxidase I (coI), 450 bp of control region (CR)] and one nuclear gene (910 bp of rag1) in each species. One hundred and eighty samples from four geographical regions within the Indo-Malay Archipelago including a population of yellowtail from Kuwait were examined. Findings revealed that the extent of genetic structuring among populations in the semi-pelagic and pelagic, yellowtail and bigeye were lower than demersal yellowstripe, consistent with the hypothesis that pelagic species display less genetic divergence compared with demersal species. The yellowtail phylogeny identified three distinct clades with bootstrap values of 86%-99% in mtDNA and 63%-67% in rag1. However, in bigeye, three clades were also observed from mtDNA data while only one clade was identified in rag1 dataset. In yellowstripe, the mtDNA tree was split into three closely related clades and two clades in rag1 tree with bootstraps value of 73%-99% and 56% respectively. However, no geographic structure appears in both mtDNA and rag1 datasets. Hierarchical molecular variance analysis (AMOVA), pair wise FST comparisons and the nearest-neighbour statistic (Snn ) showed significant genetic differences among Kuwait and Indo-Malay yellowtail. Within the Indo-Malay Archipelago itself, two distinct mitochondrial lineages were detected in yellowtail suggesting potential cryptic species. Findings suggests varying degrees of genetic structuring, key information relevant to management of exploited stocks, though more rapidly evolving genetic markers should be used in future to better delimit the nature and dynamics of putative stock boundaries.
    Matched MeSH terms: Population Dynamics
  4. Smith JD
    J Math Biol, 2004 Jan;48(1):105-18.
    PMID: 14685774
    A canonical/lognormal model for human demography is established, specifying the net maternity function and the age distribution for mothers of new-borns using a single macroscopic parameter vector of dimension five. The age distribution of mothers is canonical, while the net maternity function normalizes to a lognormal density. Comparison of an actual population with the model serves to identify anomalies in the population which may be indicative of phase transitions or influences from levels outside the demographic. Tracking the time development of the parameter vector may be used to predict the future state of a population, or to interpolate for data missing from the record. In accordance with classical theoretical considerations of Backman, Prigogine, et al., it emerges that the logarithm of a mother's age is the most fundamental time variable for demographic purposes.
    Matched MeSH terms: Population Dynamics
  5. Alebraheem J, Abu-Hassan Y
    J Math Biol, 2023 Apr 27;86(5):84.
    PMID: 37103566 DOI: 10.1007/s00285-023-01914-8
    A characteristic of ecosystems is the existence of manifold of independencies which are highly complex. Various mathematical models have made considerable contributions in gaining a better understanding of the predator-prey interactions. The main components of any predator-prey models are, firstly, how the different population classes grow and secondly, how the prey and predator interacts. In this paper, the two populations' growth rates obey the logistic law and the carrying capacity of the predator depends on the available number of prey are considered. Our aim is to clarify the relationship between models and Holling types functional and numerical responses in order to gain insights into predator interferences and to answer an important question how competition is carried out. We consider a predator-prey model and a two-predator one-prey model to explain the idea. The novel approach is explained for the mechanism measurement of predator interference through depending on numerical response. Our approach gives good correspondence between an important real data and computer simulations.
    Matched MeSH terms: Population Dynamics
  6. Bong LJ, Neoh KB, Jaal Z, Lee CY
    J Med Entomol, 2012 May;49(3):451-60.
    PMID: 22679850
    The life history characteristics of the rove beetle Paederus fuscipes Curtis were studied under laboratory conditions using three field strains from Malaysia: Desa Wawasan (DW), Sri Pinang (SP), and Ampang Jajar (AJ). The total development time of immature stages differed significantly among the three strains, especially between DW (17.43 +/- 0.16 d), SP (18.60 +/- 0.19 d), and AJ (18.68 +/- 0.22 d). Adult females and males from DW also exhibited a shorter life span, although the difference among strains was not significant. In terms of fecundity, the numbers of eggs laid per female for DW, SP, and AJ were 121.28 +/- 15.98, 127.30 +/- 18.01, and 147.45 +/- 17.12, respectively. Additionally, because of the shorter life span in DW strain, two apparent peaks in age-stage specific fecundity were detected. The beetles compensated for their shorter life span by increasing their reproductive activity to sustain the progeny in the population. The intrinsic rates of increase (r) of P. fuscipes from DW, SP, and AJ were 0.0773 +/- 0.0046 d(-1), 0.0788 +/- 0.0051 d(-1), and 0.0873 +/- 0.0054 d(-1), respectively; and the net reproduction rates (R0) were 40.09 +/- 7.39 offspring, 45.29 +/- 8.74 offspring, and 42.34 +/- 8.25 offspring, respectively. The mean generation time of P. fuscipes from AJ was 43.08 +/- 1.07 d, which was significantly higher than that from DW (47.95 +/- 1.36 d) and SP (48.57 +/- 1.43 d). The total immature development time of P. fuscipes in this study was shorter than values reported in previous studies.
    Matched MeSH terms: Population Dynamics
  7. Tee HS, Saad AR, Lee CY
    J Med Entomol, 2011 Jul;48(4):797-805.
    PMID: 21845938
    The population size, age-class structure, and movement of the American cockroach, Periplaneta americana (L.) (Dictyoptera: Blattidae), were studied in three sewers in Penang, Malaysia, from September 2008 to October 2009. Eighteen to 20 glass-jar traps (two per manhole) were deployed for a 24-h period during each sampling occasion at each sewer. Adults and nymphs were active throughout the study period, with an average monthly trap catch of 57-97 adults and 79-99 nymphs. The mean proportions of adults and nymphs at the three sewers ranged from 0.47 to 0.57. Of the 2177 male and 2717 female cockroaches marked and released over the three sewers, recapture rates were 29.4-45.8 and 30.8-47.0%, respectively. The proportion of marked males and females did not differ significantly from the proportion of recaptured marked males and females. However, the mean number of times a marked female was recaptured was significantly greater than that of males. Of the 783 males and 1,030 females that were marked and recaptured, 19.4 and 24.7%, respectively, had moved between manholes, and significantly more females than males moved between manholes. Of the 406 recaptured marked adults that moved between manholes, 90.4% moved a distance of 2-20 m from their initial release site; one male moved 192 m, the longest distance recorded. Trap catch on each sampling occasion was positively correlated with daily mean temperature. The number of cockroach movements between manholes also was correlated with the mean daily minimum temperature.
    Matched MeSH terms: Population Dynamics
  8. Ravindran J, Mathews A
    J Obstet Gynaecol (Lahore), 1996 Mar;16(2):86-8.
    PMID: 12292342
    "This paper aims to show that the establishment of a better data collection and reporting system in Malaysia since 1991 has led to an apparent increase in the maternal mortality ratio.... Because of improved surveillance, the maternal mortality ratio may continue to appear to rise for a few years but should decline after that reflecting the improvement in the health status and service delivery in Malaysia."
    Matched MeSH terms: Population Dynamics
  9. Suzuki RO, Numata S, Okuda T, Nur Supardi MN, Kachi N
    J Plant Res, 2009 Jan;122(1):81-93.
    PMID: 19037582 DOI: 10.1007/s10265-008-0198-0
    We examined relationships between mortality rate, relative growth rate (RGR), and spatial patterns of three growth stages (small, medium, and large trees) for 11 dipterocarp species in the Pasoh 50-ha plot. Mortality rates for these species tended to be positively correlated with RGRs, although the correlation was significant only at the small-tree stage. Seven species with high growth and mortality rates exhibited peaks in spatial aggregation at small distances (<100 m) in small trees, but this aggregation disappeared in medium and large trees. In contrast, the other four species with low growth and mortality rates aggregated at large distances (>200 m) throughout the three growth stages in all but one species. Negative associations between different growth stages were observed only for the high-mortality species, suggesting density-dependent mortality. The high-mortality species showed habitat associations with topography, soil type, and the forest regeneration phase after gap formation, whereas the three low-mortality species only had associations with the forest regeneration phase. A randomization procedure revealed that these habitat associations explained little of their spatial aggregation. Our results suggest that the growth strategy has a large effect on the structuring of the spatial distribution of tree species through mortality processes.
    Matched MeSH terms: Population Dynamics
  10. Leung SF
    J Popul Econ, 1994;7(4):379-92.
    PMID: 12288505
    Matched MeSH terms: Population Dynamics
  11. Leung SF
    J Popul Econ, 1988 Oct;1(2):95-114.
    PMID: 12282511
    "This paper presents a critical evaluation of three widely used tests for sex preferences: sex ratio, parity progression ratio and ordinary least squares [OLS] regression of birth interval. We show that under some appropriate conditions, the sex ratio is a valid test for sex preferences. The methods of parity progression ratio and OLS regression of birth interval fail to deal with right censoring and time varying covariates, which reduce the power of the tests. We suggest the use of hazard estimation to test for sex preferences. We demonstrate the differences among the tests by analyzing the retrospective fertility histories of the Chinese and the Malays in Malaysia. We find that unlike the two conventional methods, the hazard estimation gives clear and strong evidence of sex preferences among the Chinese in Malaysia."
    Matched MeSH terms: Population Dynamics
  12. Alibrahim OA, Al-Sadat N, Elawad NA
    J Public Health Afr, 2010 Sep 01;1(1):e7.
    PMID: 28299041 DOI: 10.4081/jphia.2010.e7
    Depression is one of the leading causes of mortality and morbidity worldwide. In the year 2000 depression accounted for 4.4% of the global disability adjusted life years (DALYs). The Kingdom of Saudi Arabia (KSA) has a population of 28 million people and is one of the countries experiencing demographic transition in its population structure. Improvements in socioeconomic status have been shown to be associated with increased chronic diseases including chronic mental diseases like depression, but still there is no comprehensive review summarizing the various reports currently existing in the literature. Although individual studies within Saudi Arabia have reported prevalence rates and risks, the quality of such studies need to be subjected to rigorous assessment and their findings pooled to give combined weighted evidence that will provide basis for targeted intervention. Pooled risks have the advantage of adjusting inherent variations within sampled populations and therefore providing more reliable estimates even though there are concerns about possible magnification of smaller individual risks.
    Matched MeSH terms: Population Dynamics
  13. Vythilingam I, Singh KI, Mahadevan S, Zaridah MS, Ong KK, Abidin MH
    J Am Mosq Control Assoc, 1993 Dec;9(4):467-9.
    PMID: 8126485
    Mosquito collections were carried out from May to June 1992 and from September to December 1992 in an area where a case of Japanese encephalitis was confirmed. A total of 40,072 mosquitoes belonging to 35 species and 8 genera were collected. The dominant species in that locality were Culex vishnui, Culex tritaeniorhynchus, Culex pseudovishnui, Culex gelidus, Aedes butleri, and Mansonia uniformis.
    Matched MeSH terms: Population Dynamics
  14. Montgomery MR, Richards T, Braun HI
    J Am Stat Assoc, 1986 Jun;81(394):297-309.
    PMID: 12155406
    This study examines the possibility that estimation of the effect of breast-feeding on infant survival is affected by selection bias, in that children who are healthier at birth may be more likely to be breast-fed. Data are from the 1976 Malaysian Family Life Survey. "Ordinary logit models for breast-feeding and survival are estimated, and the results suggest that selection is indeed present. For example, children of higher birth weight appear to be more likely to be breast-fed and likely to survive. In addition, weight at birth and the duration of breast-feeding appear to be linked." Using birth weight as an indicator for the child's health, the authors conclude that "the direct influence of breast-feeding on survival remains of overwhelming importance even after corrections for selection bias are made."
    Matched MeSH terms: Population Dynamics
  15. Mohamed WN, Diamond I, Smith PW
    J R Stat Soc Ser A Stat Soc, 1998;161(3):349-66.
    PMID: 12348725
    "A graphical chain modelling approach is used to study the determinants of neonatal and post-neonatal mortality in Malaysia. This approach provides an easily interpretable empirical description and illustrates explicitly the conditional independence structure between each pair of variables. The interpretation can be read directly from a mathematical graph. Besides examining the direct association of each determinant on mortality, we also examine the effects of socio-economic determinants on intermediate determinants to understand the pathways through which the socioeconomic determinants affect the chance of mortality. The data anlaysed come from the second Malaysian Family Life Survey, fielded between August 1988 and January 1989. "
    Matched MeSH terms: Population Dynamics*
  16. Roslan MA, Ngui R, Vythilingam I, Sulaiman WYW
    J Vector Ecol, 2017 12;42(2):298-307.
    PMID: 29125255 DOI: 10.1111/jvec.12270
    The present study compared the performance of sticky traps in order to identify the most effective and practical trap for capturing Aedes aegypti and Aedes albopictus mosquitoes. Three phases were conducted in the study, with Phase 1 evaluating the five prototypes (Models A, B, C, D, and E) of sticky trap release-and-recapture using two groups of mosquito release numbers (five and 50) that were released in each replicate. Similarly, Phase 2 compared the performance between Model E and the classical ovitrap that had been modified (sticky ovitrap), using five and 50 mosquito release numbers. Further assessment of both traps was carried out in Phase 3, in which both traps were installed in nine sampling grids. Results from Phase 1 showed that Model E was the trap that recaptured higher numbers of mosquitoes when compared to Models A, B, C, and D. Further assessment between Model E and the modified sticky ovitrap (known as Model F) found that Model F outperformed Model E in both Phases 2 and 3. Thus, Model F was selected as the most effective and practical sticky trap, which could serve as an alternative tool for monitoring and controlling dengue vectors in Malaysia.
    Matched MeSH terms: Population Dynamics
  17. Kim O-k, Shah IH
    Kajok Kyehoek Nonjip, 1979 Nov;6:142-58.
    PMID: 12178433
    PIP: It is generally believed that extended families encourage high fertility, but a review of the theoretical discussions and empirical research examining the relationship between family type and fertility fails to show any support for the customary belief. Nuclear families consist of husband, wife, and their immediate children. The extended family is broadly defined as any group of related persons living together which includes but is larger than the nuclear family. The main theoretical discussions of extended family and fertility are by Davis (1957); Davis and Blake (1956); Lorimer (1954); and Goode (1963; 1964). In the patrilocal extended family, the wife wants to have offspring as early as possible to strengthen the family line and her own status in the household. In a truly joint household the authority of the elders continues after marriage; the reproductive behavior of a couple is subject to their influence. Less intimate or less intense interspousal communication precludes the possibility of discussion on fertility-related problems and family planning. Younger age at marriage and lack of privacy contributes to higher fertility. According to Goode extended family behavior is characterized by more rules for behavior, while nuclear families emphasize the conjugal bond. Since most affinal and consanguineal kin are excluded from day-to-day decisions in the nuclear family there are weaker reciprocal controls.
    Matched MeSH terms: Population Dynamics
  18. Allotey P, Reidpath DD, Yasin S, Chan CK, de-Graft Aikins A
    Lancet, 2011 Feb 5;377(9764):450-1.
    PMID: 21074257 DOI: 10.1016/S0140-6736(10)61856-9
    Matched MeSH terms: Population Dynamics
  19. Chan JCN, Lim LL, Wareham NJ, Shaw JE, Orchard TJ, Zhang P, et al.
    Lancet, 2021 Dec 19;396(10267):2019-2082.
    PMID: 33189186 DOI: 10.1016/S0140-6736(20)32374-6
    Matched MeSH terms: Population Dynamics
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