Displaying publications 61 - 80 of 317 in total

Abstract:
Sort:
  1. DeVantier L, Alcala A, Wilkinson C
    Ambio, 2004 Feb;33(1-2):88-97.
    PMID: 15083654
    The Sulu-Sulawesi Sea, with neighboring Indonesian Seas and South China Sea, lies at the center of the world's tropical marine biodiversity. Encircled by 3 populous, developing nations, the Philippines, Indonesia and Malaysia, the Sea and its adjacent coastal and terrestrial ecosystems, supports ca. 33 million people, most with subsistence livelihoods heavily reliant on its renewable natural resources. These resources are being impacted severely by rapid population growth (> 2% yr-1, with expected doubling by 2035) and widespread poverty, coupled with increasing international market demand and rapid technological changes, compounded by inefficiencies in governance and a lack of awareness and/or acceptance of some laws among local populations, particularly in parts of the Philippines and Indonesia. These key root causes all contribute to illegal practices and corruption, and are resulting in severe resource depletion and degradation of water catchments, river, lacustrine, estuarine, coastal, and marine ecosystems. The Sulu-Sulawesi Sea forms a major geopolitical focus, with porous borders, transmigration, separatist movements, piracy, and illegal fishing all contributing to environmental degradation, human suffering and political instability, and inhibiting strong trilateral support for interventions. This review analyzes these multifarious environmental and socioeconomic impacts and their root causes, provides a future prognosis of status by 2020, and recommends policy options aimed at amelioration through sustainable management and development.
    Matched MeSH terms: Population Dynamics*
  2. Deith MCM, Brodie JF
    Proc Biol Sci, 2020 03 11;287(1922):20192677.
    PMID: 32156211 DOI: 10.1098/rspb.2019.2677
    Unsustainable hunting is emptying forests of large animals around the world, but current understanding of how human foraging spreads across landscapes has been stymied by data deficiencies and cryptic hunter behaviour. Unlike other global threats to biodiversity like deforestation, climate change and overfishing, maps of wild meat hunters' movements-often based on forest accessibility-typically cover small scales and are rarely validated with real-world observations. Using camera trapping data from rainforests across Malaysian Borneo, we show that while hunter movements are strongly correlated with the accessibility of different parts of the landscape, accessibility measures are most informative when they integrate fine-scale habitat features like topography and land cover. Measures of accessibility naive to fine-scale habitat complexity, like distance to the nearest road or settlement, generate poor approximations of hunters' movements. In comparison, accessibility as measured by high-resolution movement models based on circuit theory provides vastly better reflections of real-world foraging movements. Our results highlight that simple models incorporating fine-scale landscape heterogeneity can be powerful tools for understanding and predicting widespread threats to biodiversity.
    Matched MeSH terms: Population Dynamics
  3. Dieng H, Rahman GM, Abu Hassan A, Che Salmah MR, Satho T, Miake F, et al.
    Int J Biometeorol, 2012 Jan;56(1):113-20.
    PMID: 21267602 DOI: 10.1007/s00484-011-0402-0
    Larvae of Aedes albopictus Skuse typically inhabit natural and artificial containers. Since these larval habitats are replenished by rainfall, Ae. albopictus may experience increased loss of immature stages in areas with high levels of rainfall. In this study, we investigated the effects of rainfall and container water level on population density, and oviposition activity of Ae. albopictus. In field and laboratory experiments, we found that rainfall resulted in the flushing of breeding habitats. Excess rain negatively impacted larval and pupal retention, especially in small habitats. When filled with water to overflowing, container habitats were significantly repellent to ovipositing females. Taken together, these data suggest that rainfall triggers population loss of Ae. albopictus and related species through a direct detrimental effect (flushing out) and an indirect effect (ovipositional repellency).
    Matched MeSH terms: Population Dynamics
  4. Dinh TD, Ambak MA, Hassan A, Phuong NT
    Pak J Biol Sci, 2007 Oct 01;10(19):3284-94.
    PMID: 19090143
    This study describe the reproductive biological characteristics and population parameters of the goby, Pseudapocryptes elongatus (Cuvier, 1816), in the coastal mud flat areas of the Mekong Delta, Vietnam. A total of 1058 specimens was collected from January 2004 to June 2005 and results showed that the breeding season occurred with two spawning peaks in July and October. Length at first maturity (L(m)) was 15.4 and 16.3 cm for females and males, respectively. The batch fecundity estimates ranged from 2,652 to 29,406 hydrated oocytes per ovary in the fish ranging from 12.8 to 22.4 cm TL. Length frequency data of the goby ranging from 9.0 to 24.0 cm TL were analyzed using the FiSAT II software. The von Bertalanffy growth parameters were determined as L8 = 25.9 cm, K = 0.66 year(-1) and t(o) = - 0.26 year(-1). The longevity (t(max)) of the goby was estimated to be 4.55 years. There were two recruitment peaks with very different magnitudes and the means of these two peaks were separated by an interval of 5 months. Length at first capture (L(c)) was 10.05 cm, the instantaneous fishing mortality rate (F = 1.38 year(-1)) and natural mortality rate (M = 1.46 year(-1)) accounted for 49 and 51% of the total mortality (Z = 2.84 year(-1)), respectively. Relative yield-per-recruit and biomass-per-recruit analyses gave E(max) = 0.65, E0.1 = 0.55 and E0.5 = 0.33. Results show that the fish stock is subjected to growth overexploitation.
    Matched MeSH terms: Population Dynamics
  5. Dixon G
    Asia Pac Popul J, 1993 Jun;8(2):23-54.
    PMID: 12287522
    PIP: Malaysian infant mortality differentials are a worthwhile subject for study, because socioeconomic development has very clearly had a differential impact by ethnic group. The Chinese rates of infant mortality are significantly lower than the Malay or Indian rates. Instead of examining the obvious access to care issues, this study considered factors related to the culture of infant care. Practices include the Chinese confinement of the mother in the first month after childbirth ("pe'i yue") and Pillsbury's 12 normative rules for Malaysian Chinese care. Malay practices vary widely by region and history. Indian mothers are restricted by diet. Data-recording flaws do not permit analysis of Sarawak or Sabah. The general assumption that Western medicine favors better health for mothers and infants is substantiated among peninsular communities, however, there are also negative impacts which affect infant mortality. The complex interaction of factors impacting on infant mortality reported in seven previous studies is discussed. A review of these studies reveals that immediate causes are infections, injuries, and dehydration. Indirect causes are birth weight or social and behavioral factors such as household income or maternal education. Indirect factors, which are amenable to planned change and influence the biological proximate determinants of infant mortality, are identified as birth weight, maternal age at birth, short pregnancy intervals or prior reproductive loss, sex of the child, birth order, duration of breast feeding and conditions of supplementation, types of household water and sanitation, year of child's birth, maternal education, household income and composition, institution of birth, ethnicity, and rural residence. Nine factors are identified empirically as not significant: maternal hours of work in the child's first year, maternal occupation, distance from home to workplace, presence of other children or servants, incidence of epidemics in the child's first year of life, community types of sanitation, prices and availability of infant foods, and access to various types of medical care. Future empirical study should consider factors such as class differences, place of residence, or extent of illiteracy as underlying or related to ethnicity. Policy-makers should be aware that future decline in infant mortality rates may depend on the blending of traditional with modern practices.
    Matched MeSH terms: Population Dynamics
  6. Dorall RF
    Asian Migr, 1988 May-Jun;1(3):88-93.
    PMID: 12281348
    This article surveys the arrivals of Muslim refugees from countries in Southeast Asia who have not only come to Malaysia for political refuge, but who have also stayed on, in many instances integrating into the local Muslim community. The author concludes that Burmese, Thai, and Filipino Muslim refugee-cum-migrants, and the estimated 500,000 illegal Indonesian migrant workers in East and Peninsular Malaysia make the presence of economic migrants in Malaysia's towns and rural sectors a far more pressing concern to Malaysians than that posed by the arrival of genuine political refugees. Only the Indonesians present in Malaysia are consistently termed by all parties as illegal migrants and some of them have been subjected to well-publicized deportation by the Malaysian immigration authorities. Sympathy for fellow-Muslims in distress explains Malaysia's open-door policy to Muslim refugees. The Koran specifically enjoins Muslims to assist Muslim refugees who have been persecuted by others. However, the necessity to maintain regional political and military alliances, principally as a bulwark against Communism, and the Malay--Non-Malay, Muslim--Non-Muslim dichotomy in Malaysia which almost evenly divides Malaysia's 16 million population into mutually antagonistic halves, results in any overt public policy in favor of Malays and Muslims to be immediately denounced by the other half of the population as a move against the Non-Malays and Non-Muslims. Without political and media attention, the refugees live wherever they can find work, as do hundreds of thousands of mainly Indonesian illegal migrant workers. They surreptitiously get their children admitted to public schools, and through bribery, can even get Malaysian identification papers. Malaysia is a relatively tranquil haven for Malaysia's Muslim refugees compared to their homelands, but their continued stay remains dependent on the ever-present struggle for more equitable sharing of political and economic power between the different ethnic groups in Malaysia. At present, it is deemed inopportune to discuss publicly the issue of Muslim refugees in Malaysia. To do so would be to invite strong emotional responses from Malaysian Muslim groups objecting to refugee repatriation to what they see as continued persecution in Southeast Asia's non-Muslim countries, and from non-Muslim Malaysians who see in their continued presence a possible long-term demographic threat. Furthermore, the presence of Muslim evacuees granted refugee status brings painful memories as to why non-Muslim refugees principally from Indochina were denied such a similar privilege.
    Matched MeSH terms: Population Dynamics
  7. Drescher J, Blüthgen N, Feldhaar H
    Mol Ecol, 2007 Apr;16(7):1453-65.
    PMID: 17391269
    Invasive species are one of the main sources of the ongoing global loss of biodiversity. Invasive ants are known as particularly damaging invaders and their introductions are often accompanied by population-level behavioural and genetic changes that may contribute to their success. Anoplolepis gracilipes is an invasive ant that has just recently received increased attention due to its negative impact on native ecosystems. We examined the behaviour and population structure of A. gracilipes in Sabah, Malaysia. A total of 475 individuals from 24 colonies were genotyped with eight microsatellite markers. Intracolonial relatedness was high, ranging from 0.37 to 1 (mean +/- SD: 0.82 +/- 0.04), while intercolonial relatedness was low (0.0 +/- 0.02, range -0.5-0.76). We compared five distinct sampling regions in Sabah and Brunei. A three-level hierarchical F-analysis revealed high genetic differentiation among colonies within the same region, but low genetic differentiation within colonies or across regions. Overall levels of heterozygosity were unusually high (mean H(O) = 0.95, mean H(E) = 0.71) with two loci being entirely heterozygous, indicating an unusual reproductive system in this species. Bioassays revealed a negative correlation between relatedness and aggression, suggesting kinship as one factor facilitating supercolony formation in this species. Furthermore, we genotyped one individual per nest from Sabah (22 nests), Sarawak (one nest), Brunei (three nests) and the Philippines (two nests) using two mitochondrial DNA markers. We found six haplotypes, two of which included 82.1% of all sequences. Our study shows that the sampled area in Sabah consists of a mosaic of differently interrelated nests in different stages of colony establishment. While some of the sampled colonies may belong to large supercolonies, others are more likely to represent recently introduced or dispersed propagules that are just beginning to expand.
    Matched MeSH terms: Population Dynamics
  8. Duza MB
    Popul Sci, 1987;7:1-30.
    PMID: 12315536
    "The present paper attempts to provide an analytical profile of development and human resources in [12] selected [Islamic] countries." The countries--Bangladesh, Somalia, Pakistan, Indonesia, Egypt, Turkey, Malaysia, Algeria, Iraq, Saudi Arabia, Kuwait, and United Arab Emirates--vary in income levels from low to high and in population size from 1 million to 159 million. Using data from the World Bank and the Population Council, comparisons are made on the basis of mortality and fertility levels, family size, income, urbanization, labor force size and growth, education, nutrition, and health. Governmental policy changes and future directions are discussed.
    Matched MeSH terms: Population Dynamics
  9. Edwards DP, Woodcock P, Edwards FA, Larsen TH, Hsu WW, Benedick S, et al.
    Ecol Appl, 2012 Mar;22(2):561-71.
    PMID: 22611854 DOI: 10.1890/11-1362.1
    A key driver of rain forest degradation is rampant commercial logging. Reduced-impact logging (RIL) techniques dramatically reduce residual damage to vegetation and soils, and they enhance the long-term economic viability of timber operations when compared to conventionally managed logging enterprises. Consequently, the application of RIL is increasing across the tropics, yet our knowledge of the potential for RIL also to reduce the negative impacts of logging on biodiversity is minimal. We compare the impacts of RIL on birds, leaf-litter ants, and dung beetles during a second logging rotation in Sabah, Borneo, with the impacts of conventional logging (CL) as well as with primary (unlogged) forest. Our study took place 1-8 years after the cessation of logging. The species richness and composition of RIL vs. CL forests were very similar for each taxonomic group. Both RIL and CL differed significantly from unlogged forests in terms of bird and ant species composition (although both retained a large number of the species found in unlogged forests), whereas the composition of dung beetle communities did not differ significantly among forest types. Our results show little difference in biodiversity between RIL and CL over the short-term. However, biodiversity benefits from RIL may accrue over longer time periods after the cessation of logging. We highlight a severe lack of studies investigating this possibility. Moreover, if RIL increases the economic value of selectively logged forests (e.g., via REDD+, a United Nations program: Reducing Emissions from Deforestation and Forest Degradation in Developing Countries), it could help prevent them from being converted to agricultural plantations, which results in a tremendous loss of biodiversity.
    Matched MeSH terms: Population Dynamics
  10. Edwards DP, Larsen TH, Docherty TD, Ansell FA, Hsu WW, Derhé MA, et al.
    Proc Biol Sci, 2011 Jan 7;278(1702):82-90.
    PMID: 20685713 DOI: 10.1098/rspb.2010.1062
    Southeast Asia is a hotspot of imperiled biodiversity, owing to extensive logging and forest conversion to oil palm agriculture. The degraded forests that remain after multiple rounds of intensive logging are often assumed to be of little conservation value; consequently, there has been no concerted effort to prevent them from being converted to oil palm. However, no study has quantified the biodiversity of repeatedly logged forests. We compare the species richness and composition of birds and dung beetles within unlogged (primary), once-logged and twice-logged forests in Sabah, Borneo. Logging had little effect on the overall richness of birds. Dung beetle richness declined following once-logging but did not decline further after twice-logging. The species composition of bird and dung beetle communities was altered, particularly after the second logging rotation, but globally imperiled bird species (IUCN Red List) did not decline further after twice-logging. Remarkably, over 75 per cent of bird and dung beetle species found in unlogged forest persisted within twice-logged forest. Although twice-logged forests have less biological value than primary and once-logged forests, they clearly provide important habitat for numerous bird and dung beetle species. Preventing these degraded forests from being converted to oil palm should be a priority of policy-makers and conservationists.
    Matched MeSH terms: Population Dynamics
  11. Endersby NM, McKechnie SW, Ridland PM, Weeks AR
    Mol Ecol, 2006 Jan;15(1):107-18.
    PMID: 16367834
    The diamondback moth, Plutella xylostella, is renowned for developing resistance to insecticides and causing significant economic damage to Brassica vegetable crops throughout the world. Yet despite its economic importance, little is known about the population structure and movement patterns of this pest both at local and regional scales. In Australia, the movement patterns and insecticide resistance status of P. xylostella infesting canola, vegetables, forage brassicas and weeds have fundamental implications for the management of this pest. Here we use six polymorphic microsatellite loci to investigate population structure and gene flow in Australian populations of P. xylostella. Samples of P. xylostella from New Zealand, Malaysia, Indonesia and Kenya were also scored at these loci. We found no evidence of population structure within Australia, with most populations having low inbreeding coefficients and in Hardy-Weinberg equilibrium. In addition, a sample from the North Island of New Zealand was indistinguishable from the Australian samples. However, large genetic differences were found between the Australia/New Zealand samples and samples from Kenya, Malaysia and Indonesia. There was no relationship between genetic distance and geographic distance among Australian and New Zealand samples. Two of the loci were found to have null alleles, the frequency of which was increased in the populations outside the Australia/New Zealand region. We discuss these results with reference to insecticide resistance management strategies for P. xylostella in Australia.
    Matched MeSH terms: Population Dynamics
  12. Ewers RM, Boyle MJ, Gleave RA, Plowman NS, Benedick S, Bernard H, et al.
    Nat Commun, 2015 Apr 13;6:6836.
    PMID: 25865801 DOI: 10.1038/ncomms7836
    Invertebrates are dominant species in primary tropical rainforests, where their abundance and diversity contributes to the functioning and resilience of these globally important ecosystems. However, more than one-third of tropical forests have been logged, with dramatic impacts on rainforest biodiversity that may disrupt key ecosystem processes. We find that the contribution of invertebrates to three ecosystem processes operating at three trophic levels (litter decomposition, seed predation and removal, and invertebrate predation) is reduced by up to one-half following logging. These changes are associated with decreased abundance of key functional groups of termites, ants, beetles and earthworms, and an increase in the abundance of small mammals, amphibians and insectivorous birds in logged relative to primary forest. Our results suggest that ecosystem processes themselves have considerable resilience to logging, but the consistent decline of invertebrate functional importance is indicative of a human-induced shift in how these ecological processes operate in tropical rainforests.
    Matched MeSH terms: Population Dynamics
  13. Faheem M, Saeed S, Sajjad A, Wang S, Ali A
    PLoS One, 2019;14(9):e0222635.
    PMID: 31568475 DOI: 10.1371/journal.pone.0222635
    Aphids are major pests of wheat crop in Pakistan inflicting considerable economic losses. A better knowledge of landscape scale spatial distribution of aphids and their natural enemies could be used to improve integrated pest management programs. Therefore, the present study aimed to document spatio-temporal variations in populations of wheat aphids and their natural enemies in Pakistan. The 2-year survey study was carried out at ten experimental farms located in five districts of four contrasted agro-ecological zones of eastern Pakistan (Punjab area) i.e. District Chakwal in arid zone, Gujranwala in rice-cropped zone, Faisalabad in central mixed-cropped zone, and Khanewal and Multan in cotton-cropped zone. The dominant aphid species i.e. Schizaphis graminum, Rhopalosiphum padi, R. maidis and Sitobion avenae varied significantly among the five districts surveyed. The population of S. graminum was observed more abundant in arid, R. padi in rice, S. avenae in aird and rice, and R. maidis in cotton-I zones. Aphids ended their population dynamics on 25th March in central mixed-cropped zone and 12th April in other three zones. Various species of natural enemies, mainly Coccinella septumpunctata, C. undecimpunctata, Menochilus sexmaculata, Chrysoperla carnea, Syrphidae and parasitoid mummies were inconsistently observed in four agro-ecological zones. The population of C. septumpunctata, was observed more abundant in rice zone, C. undecimpunctata and C. carnea in cotton-I and arid zones, M. sexmaculata in cotton-I and II zones, Syrphidae in cotton-I zone and parasitoid mummies in rice and arid zones. There were no clear relationships between aphid and the natural enemy populations. The present study may serve as a baseline regarding distribution of wheat aphids and their natural enemies and the results provided insights for further studies on the potential top-down (natural enemies) versus bottom-up (fertilization and irrigation regimes) forces in management of wheat aphids in eastern Pakistan.
    Matched MeSH terms: Population Dynamics
  14. Faruk A, Belabut D, Ahmad N, Knell RJ, Garner TW
    Conserv Biol, 2013 Jun;27(3):615-24.
    PMID: 23692022 DOI: 10.1111/cobi.12062
    Agriculturally altered vegetation, especially oil-palm plantations, is rapidly increasing in Southeast Asia. Low species diversity is associated with this commodity, but data on anuran diversity in oil-palm plantations are lacking. We investigated how anuran biological diversity differs between forest and oil-palm plantation, and whether observed differences in biological diversity of these areas is linked to specific environmental factors. We hypothesized that biological diversity is lower in plantations and that plantations support a larger proportion of disturbance-tolerant species than forest. We compared species richness, abundance, and community composition between plantation and forest areas and between site types within plantation and forest (forest stream vs. plantation stream, forest riparian vs. plantation riparian, forest terrestrial vs. plantation terrestrial). Not all measures of biological diversity differed between oil-palm plantations and secondary forest sites. Anuran community composition, however, differed greatly between forest and plantation, and communities of anurans in plantations contained species that prosper in disturbed areas. Although plantations supported large numbers of breeding anurans, we concluded the community consisted of common species that were of little conservation concern (commonly found species include Fejervarya limnocharis, Microhyla heymonsi, and Hylarana erythrea). We believe that with a number of management interventions, oil-palm plantations can provide habitat for species that dwell in secondary forests.
    Matched MeSH terms: Population Dynamics
  15. Feeney G
    Asian Pac Popul Forum, 1991;5(2-3):51-5, 76-87.
    PMID: 12343438
    "The past 20 years have seen extensive elaboration, refinement, and application of the original Brass method for estimating infant and child mortality from child survivorship data. This experience has confirmed the overall usefulness of the methods beyond question, but it has also shown that...estimates must be analyzed in relation to other relevant information before useful conclusions about the level and trend of mortality can be drawn.... This article aims to illustrate the importance of data analysis through a series of examples, including data for the Eastern Malaysian state of Sarawak, Mexico, Thailand, and Indonesia. Specific maneuvers include plotting completed parity distributions and 'time-plotting' mean numbers of children ever born from successive censuses. A substantive conclusion of general interest is that data for older women are not so widely defective as generally supposed."
    Matched MeSH terms: Population Dynamics
  16. Fix AG
    Am J Hum Biol, 1989;1(4):463-469.
    PMID: 28514113 DOI: 10.1002/ajhb.1310010409
    The fertility and parameters of population growth of the Semai Senoi of Malaysia are studied by using a two-census method based on nonstable population theory. Semai fertility is shown to be moderately high; female completed fertility is 7.42 children and the crude birth rate is greater than 0.050. Previous estimates of Semai mortality rates are also moderately high but are insufficient to balance birth; thus, the overall rate of growth is presently nearly 2%. Compared with an earlier description of the pre-1969 Semai population, fertility has increased markedly leading to a nearly threefold increase in the annual growth rate.
    Matched MeSH terms: Population Dynamics
  17. Foo FK, Singham GV, Othman AS, Lee CY
    J Econ Entomol, 2011 Oct;104(5):1675-9.
    PMID: 22066198
    A survey of the infestation rate of colonies of Macrotermes gilvus (Hagen) (Termitidae: Macrotermitinae) with the koinobiont endoparasitoid Misotermes mindeni Disney & Neoh (Diptera: Phoridae) was conducted in Malaysia from September 2009 to January 2011 in the states of Kedah, Penang, Perak, Selangor, Kuala Lumpur, Johor, Terengganu, and Sarawak. Of the 1,125 M. gilvus mounds surveyed, 12.4% contained termites parasitized by M. mindeni and these mounds occurred only in the states of Penang and Perak. High frequencies of mounds containing parasitized termites were found at sites in Penang: Bayan Lepas (21.1%), Minden Campus of Universiti Sains Malaysia ([USM]; 24.5%), Teluk Bahang (28.0%), and Bukit Mertajam (35.0%); the lowest frequency (4.0%) was recorded from Gelugor. The parasitized colonies at all sites were classified as healthy, with exception of several from the Minden Campus of USM (96.4% healthy) and Ayer Itam (87.5% healthy). Most parasitized colonies (71.2%) had a low level of M. mindeni infestation. Only 16.7 and 12.1% of the infested colonies had moderate or high parasite infestation levels, respectively. The height of infected mounds was significantly higher than that of the healthy mounds, but there was no difference between the mound diameters of infested and uninfested mounds. Parasite infestation level was not significantly correlated with mound height or mound diameter. The ambient light intensity at sites with infested mounds was significantly lower than that of uninfested mounds. There was also a significant negative relationship between light intensity and degree of parasitism.
    Matched MeSH terms: Population Dynamics
  18. Forster P, Matsumura S
    Science, 2005 May 13;308(5724):965-6.
    PMID: 15890867
    Matched MeSH terms: Population Dynamics*
  19. Friedman B
    Soc Welfare (India), 1974 Dec 5;21(9):3.
    PMID: 12257917
    Matched MeSH terms: Population Dynamics
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links