MyMedR

Quaternary land bridges have not been universal conduits of gene flow

Cros E, Chattopadhyay B, Garg KM, Ng NSR, Tomassi S, Benedick S, et al.

Mol Ecol, 2020 07;29(14):2692-2706.

Quaternary climate oscillations are a well-known driver of animal diversification, but their effects are most well studied in areas where glaciations lead to habitat fragmentation. In large areas of the planet, however, glaciations have had the opposite effect, but here their impacts are much less well understood. This is especially true in Southeast Asia, where cyclical changes in land distribution have generated enormous land expansions during glacial periods. In this study, we selected a panel of five songbird species complexes covering a range of ecological specificities to investigate the effects Quaternary land bridges have had on the connectivity of Southeast Asian forest biota. Specifically, we combined morphological and bioacoustic analysis with an arsenal of population genomic and modelling approaches applied to thousands of genome-wide DNA markers across a total of more than 100 individuals. Our analyses show that species dependent on forest understorey exhibit deep differentiation between Borneo and western Sundaland, with no evidence of gene flow during the land bridges accompanying the last 1-2 ice ages. In contrast, dispersive canopy species and habitat generalists have experienced more recent gene flow. Our results argue that there remains much cryptic species-level diversity to be discovered in Southeast Asia even in well-known animal groups such as birds, especially in nondispersive forest understorey inhabitants. We also demonstrate that Quaternary land bridges have not been equally suitable conduits of gene flow for all species complexes and that life history is a major factor in predicting relative population divergence time across Quaternary climate fluctuations.

Matched MeSH terms: Genetics, Population*

Fulltext A holistic approach to promoting early child development: a cluster randomised trial of a group-based, multicomponent intervention in rural Bangladesh

Pitchik HO, Tofail F, Rahman M, Akter F, Sultana J, Shoab AK, et al.

BMJ Glob Health, 2021 03;6(3).

PMID: 33727278 DOI: 10.1136/bmjgh-2020-004307

INTRODUCTION: In low- and middle-income countries, children experience multiple risks for delayed development. We evaluated a multicomponent, group-based early child development intervention including behavioural recommendations on responsive stimulation, nutrition, water, sanitation, hygiene, mental health and lead exposure prevention.

METHODS: We conducted a 9-month, parallel, multiarm, cluster-randomised controlled trial in 31 rural villages in Kishoreganj District, Bangladesh. Villages were randomly allocated to: group sessions ('group'); alternating groups and home visits ('combined'); or a passive control arm. Sessions were delivered fortnightly by trained community members. The primary outcome was child stimulation (Family Care Indicators); the secondary outcome was child development (Ages and Stages Questionnaire Inventory, ASQi). Other outcomes included dietary diversity, latrine status, use of a child potty, handwashing infrastructure, caregiver mental health and knowledge of lead. Analyses were intention to treat. Data collectors were independent from implementers.

RESULTS: In July-August 2017, 621 pregnant women and primary caregivers of children<15 months were enrolled (group n=160, combined n=160, control n=301). At endline, immediately following intervention completion (July-August 2018), 574 participants were assessed (group n=144, combined n=149, control n=281). Primary caregivers in both intervention arms participated in more play activities than control caregivers (age-adjusted means: group 4.22, 95% CI 3.97 to 4.47; combined 4.77, 4.60 to 4.96; control 3.24, 3.05 to 3.39), and provided a larger variety of play materials (age-adjusted means: group 3.63, 3.31 to 3.96; combined 3.81, 3.62 to 3.99; control 2.48, 2.34 to 2.59). Compared with the control arm, children in the group arm had higher total ASQi scores (adjusted mean difference in standardised scores: 0.39, 0.15 to 0.64), while in the combined arm scores were not significantly different from the control (0.25, -0.07 to 0.54).

CONCLUSION: Our findings suggest that group-based, multicomponent interventions can be effective at improving child development outcomes in rural Bangladesh, and that they have the potential to be delivered at scale.

TRIAL REGISTRATION NUMBER: The trial is registered in ISRCTN (ISRCTN16001234).

Matched MeSH terms: Rural Population*

Fulltext Obesity among years 1 and 6 primary school children in Selangor Darul Ehsan

Bong ASL, Jaafar S

Malays J Nutr, 1996 Mar;2(1):21-7.

PMID: 22692098 MyJurnal

A study was conducted from March to June 1991 to determine the prevalence of obesity among primary school children in the State of Selangor. One School Health Team in each of the 9 Districts of Selangor participated in the collection of data, the whole project being coordinated by the Selangor State Health Department. A total of 28 rural and 24 urban schools were selected for the study, involving a total of 2,688 pupils in Standard 1 and Standard 6. The prevalence of obesity, using >120% of the reference weight-for-height as the criteria, varied considerably in the different districts, with an overall prevalence of 7.8% in the State. The proportion of boys affected (66.7%) was twice that among girls (33.3%). The prevalence of obesity of 9.8% in the urban schools was significantly higher than the 6.1% found for rural schools (p<0.0001). 151 (11.1%) were from Standard 6 and 59 (4.4%) were from Standard 1 (p<0.0001). It was also found that there was a significantly higher prevalence of obesity amongst primary 6 children (p<0.0001). Whilst the problem may not be as serious as that found in developed countries, the findings of this study should serve as an early warning to health authorities of the seriousness of the problem.

Matched MeSH terms: Rural Population; Urban Population

Fulltext Seasonal abundance of Aedes albopictus in selected urban and suburban areas in Penang, Malaysia

Rozilawati H, Zairi J, Adanan CR

Trop Biomed, 2007 Jun;24(1):83-94.

PMID: 17568381 MyJurnal

Ovitrap surveillance was conducted in a selected urban area and suburban area, ie. Taman Permai Indah(TPI) and Kampung Pasir Gebu (KPG) in Penang for 14 months. It was found that Aedes albopictus was the most abundant Aedes species in both study areas, even though a small percentage of Aedes aegypti and Culex quinquefasciatus were found to breed simultaneously in the same ovitrap. This study indicated that the main dengue vector was Ae. albopictus. A strong correlation was found between rainfall and egg population in both of the study sites (r = 0.982 and r = 0.918).

Matched MeSH terms: Population Dynamics*

"Hypertrichosis pinnae auris" in Malaysian peoples

Pallie W

Med J Malaya, 1968 Sep;23(1):67-72.

PMID: 4237562

Matched MeSH terms: Continental Population Groups*

Studies on filariasis in Malaya: field and laboratory investigations of the vectors of a rural strain of Wuchereria bancrofti

WHARTON RH

Ann Trop Med Parasitol, 1960 Apr;54:78-91.

PMID: 13844260

Matched MeSH terms: Rural Population*

The role of kin-structured migration in genetic microdifferentiation

Fix AG

Ann. Hum. Genet., 1978 Jan;41(3):329-39.

PMID: 626477

Most current models of human population structure view migration solely as a deterministic force reducing the variance in gene frequencies among the local colonies of a subdivided population. By an empirical example and through simulation experiments, it is shown that migration structured along kinship lines (by analogy to the lineal or 'kinship' effect) does not always reduce the variances of gene frequencies arising through intergenerational random genetic drift. Thus populations experiencing high rates of migration may not be genetically homogenous.

Matched MeSH terms: Genetics, Population*

THE TWIN PROBLEMS OF RURAL POVERTY AND ILL HEALTH

BIN AHMADA

Med J Malaysia, 1964 Jun;18:235-8.

PMID: 14199441

Matched MeSH terms: Rural Population*

The decline of fertility in Peninsular Malaysia

Hirschman C, Fernandez D

Genus, 1980 Jan-Jun;36(1/2):93-127.

PMID: 12263330

Matched MeSH terms: Population; Population Dynamics

ASEAN projects reviewed

Asian Pac Popul Programme News, 1980;9(1-2):9-10.

PMID: 12262042

Matched MeSH terms: Population Control*

Tobacco smoking patterns in a rural community in Negri Sembilan

Pathmanathan I

Med J Malaysia, 1974 Sep;29(1):34-9.

PMID: 4282628

Matched MeSH terms: Rural Population*

Malaria and population explosion

Williams CD

Lancet, 1968 Oct 19;2(7573):868-9.

PMID: 4175755

Matched MeSH terms: Population Growth*

Taste-thresholds for phenylthiocarbamide of some population groups. II. The thresholds of two uncivilized ethnic groups living in Malaya

LUGG JW

Ann. Hum. Genet., 1957 Mar;21(3):244-53.

PMID: 13411870

Matched MeSH terms: Population Groups*

Taste thresholds for phenylthiocarbamide of some population groups. I The thresholds of some civilized ethnic groups living in Malaya

LUGG JW, WHYTE JM

Ann. Hum. Genet., 1955 Jun;19(4):290-311.

PMID: 14388535

Matched MeSH terms: Population Groups*

Differing concepts of settlement patterns: the Malay and Chinese in Malaysia

Evers HD

Ekistics, 1977;44(263):220-5.

PMID: 12262669

Matched MeSH terms: Population; Population Characteristics

ASEAN to have common population projects

Asian Popul Programme News, 1977;6(1):7-8.

PMID: 12260254

Matched MeSH terms: Population Control*

An experiment in the control of rural malaria in Malaya

EDESON JF, WHARTON RH, WILSON T, REID JA

Med J Malaya, 1957 Sep;12(1):319-47.

PMID: 13492806

Matched MeSH terms: Rural Population*

Semai Senoi fertility and population dynamics: Two-census method

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; Population Growth

Fulltext Population genomics of grey wolves and wolf-like canids in North America

Sinding MS, Gopalakrishan S, Vieira FG, Samaniego Castruita JA, Raundrup K, Heide Jørgensen MP, et al.

PLoS Genet, 2018 11;14(11):e1007745.

PMID: 30419012 DOI: 10.1371/journal.pgen.1007745

North America is currently home to a number of grey wolf (Canis lupus) and wolf-like canid populations, including the coyote (Canis latrans) and the taxonomically controversial red, Eastern timber and Great Lakes wolves. We explored their population structure and regional gene flow using a dataset of 40 full genome sequences that represent the extant diversity of North American wolves and wolf-like canid populations. This included 15 new genomes (13 North American grey wolves, 1 red wolf and 1 Eastern timber/Great Lakes wolf), ranging from 0.4 to 15x coverage. In addition to providing full genome support for the previously proposed coyote-wolf admixture origin for the taxonomically controversial red, Eastern timber and Great Lakes wolves, the discriminatory power offered by our dataset suggests all North American grey wolves, including the Mexican form, are monophyletic, and thus share a common ancestor to the exclusion of all other wolves. Furthermore, we identify three distinct populations in the high arctic, one being a previously unidentified "Polar wolf" population endemic to Ellesmere Island and Greenland. Genetic diversity analyses reveal particularly high inbreeding and low heterozygosity in these Polar wolves, consistent with long-term isolation from the other North American wolves.

Matched MeSH terms: Genetics, Population*

Determinants of periodontitis among a rural Indian population: A case control study

Pulikkotil SJ, Nath S, Ramachandran V

Community Dent Health, 2020 Feb 27;37(1):26-31.

PMID: 32031346 DOI: 10.1922/CDH_4632Pulikkotil06

OBJECTIVES: Identify the determinants of periodontitis in a rural Indian population aged 35-44 years.

BASIC RESEARCH DESIGN: Case-control clinical and questionnaire study in a cluster sample of 50 villages.

METHODS: A total of 3000 persons were screened for the presence of periodontitis using the CDC case definition in full mouth examination. Equal numbers of cases (604 persons with periodontitis) and controls (604 without periodontitis) were recruited and interviewed with a piloted questionnaire. Univariate and multivariate analysis estimated crude and adjusted odds ratios (aOR) respectively with 95% confidence limits.

RESULTS: Six factors were determined by multivariate analysis to predict periodontitis: education less than or equal to twelve years of schooling (aOR=2.51, 95% CI=1.18-5.34), alcohol consumption (aOR= 1.7, 95% CI=1.16-2.49), consuming a non-vegetarian diet (aOR=1.38, 95% CI=1.08-1.76), not drinking milk (aOR=1.7, 95% CI= 1.29-2.24), not using a toothbrush for cleaning of teeth (aOR=2.98, 95% CI =1.71-5.21) and not cleaning teeth at least once a day (aOR=2.13, 95% CI=1.58-2.87).

CONCLUSION: Risk factors for periodontitis in a rural Indian population were identified. Further studies should validate these findings and appropriate recommendations should be developed to decrease the prevalence and burden of periodontitis in this population.

Matched MeSH terms: Rural Population*

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