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At least 793 records · Page 44Linked to original sources
PubMed1997

Alu evolution in human populations: using the coalescent to estimate effective population size.

There are estimated to be approximately 1000 members of the Ya5 Alu subfamily of retroposons in humans. This subfamily has a distribution restricted to humans, with a few copies in gorillas and chimpanzees. Fifty-seven Ya5 elements were previously cloned from a HeLa-derived randomly sheared total genomic library, sequenced, and screened for polymorphism in a panel of 120 unrelated humans. Forty-four of the 57 cloned Alu repeats were monomorphic in the sample and 13 Alu repeats were dimorphic for insertion presence/absence. The observed distribution of sample frequencies of the 13 dimorphic elements is consistent with the theoretical expectation for elements ascertained in a single diploid cell line. Coalescence theory is used to compute expected total pedigree branch lengths for monomorphic and dimorphic elements, leading to an estimate of human effective population size of approximately 18,000 during the last one to two million years.

Evolution, Molecular↗
PubMed1975

The genetics of Drosophila subobscura populations. V. A study of linkage disequilibrium in natural populations between genes and inversions of the E chromosome.

The genetics of Hk and Est-9 complex gene have been studied in Drosophila subobscura. While Hk alleles mendelize normally, Est-9 is a complex locus consisting of several very closely linked genes with active and silent alleles. Both genes are located on chromosome E; a detailed genetic map was constructed with the help of visible markers and inversions. Both Hk and Est-9 are included in or are very near to inversions of the E chromosome. While Hk does not show linkage disequilibrium either with Est-9 or inversions, Est-9 does show disequilibrium in two ways: both with inversions and between different Est-9 genes. All natural populations studied show the same kind of association between Est-9 gene combinations and inversions. It is argued that these results are better explained by selection than by neutrality.

Alleles↗
PubMedDate not supplied

Population genetics of Mexican Drosophila. I. Chromosomal variation in natural populations of Drosophila pseudoobscura from Central Mexico.

Drosophila pseudoobscura populations of Central Mexico are chromosomally highly polymorphic. Five gene arangements in the third chromosome are endemic, including the two newly described in the present article. The phylogenetic tree of the gene arrangements known in the species is shown in Figure 1. The ones found in Central Mexico all belong to the Santa Cruz "phylad", while in the northern part of the species area both Santa Cruz and Standard phylads are widespread. Some inferences concerning the evolutionary history of the species are presented.

Animals↗
PubMedDate not supplied

Population dynamics of mutant alleles under maternal effect in plant populations.

Fitness interactions via maternal effects were analyzed by constructing a mathematical model. Here, the fitness of an individual is determined by its own phenotype and the maternal phenotype. It is assumed that two alternative phenotypic states are determined by two alleles at a single locus. Under this assumption, the model developed here reduces to a social selection model of human populations that considers that the fitness of an individual is determined by the individual as well as the parental phenotypes. The effect on genetic variability of random fluctuations in the magnitude of maternal effects was studied by considering the fixation probability and the equilibrium frequency of mutant genes. It is shown that genetic variability decreases as the magnitude of variation in maternal effect intensity increases.

Alleles↗
PubMed1998

Movement of badgers (Meles meles) in a high-density population: individual, population and disease effects.

The movement of 1763 badgers trapped between 36 social groups in Woodchester Park, Gloucestershire, over 18 years was analysed to determine the frequency and duration of moves, the factors associated with a predisposition to move and the spatial pattern of movements. Of those badgers whose capture history could be categorized, nearly half had moved. Of these, 73.1% were classified as 'occasional movers', 22.1% as 'permanent movers' and 4.8% as 'frequent movers'. Most adult badgers that moved made occasional moves (78.8%, n = 67). Cubs made all types of move including permanent moves (29%, n = 10). Seventy per cent of females were non-movers compared with 37% of males. Badgers were significantly more likely to move to smaller groups, whereas male badgers were significantly more likely to move to groups with a greater proportion of females. The spatial pattern of movement differed from the distribution of groups with bovine tuberculosis in the study area. However, temporal changes in movement were significantly related to the incidence of Mycobacterium bovis infection in the following year, indicating that as the movement of badgers between groups varies so does the incidence of bovine tuberculosis in the population. This finding is of central importance in the formulation of badger control policy.

Animals↗
PubMed2001

Studies of linkage in populations. XIV. Historical changes in frequencies of gene arrangements and arrangement combinations in natural populations of Drosophila robusta.

Data are reported showing large directional changes in the frequencies of some gene arrangements and arrangement combinations in certain natural populations of Drosophila robusta in the eastern United States. The changes involve the same X-chromosomal inversion differences in two of the three localities studied and similar autosomal inversions in all three. These genetic changes provide a rare opportunity to observe evolutionary forces at work in nature. They are interpreted as being due to natural selection.

Animals↗
PubMed1987

Gc subtypes in some population groups from Israel. Comparison between world population groups and between Jews and non-Jews of the same areas.

Results of Gc subtyping on 1,222 Israelis, Arabs and Jews, are summarized and their gene frequencies are analyzed in comparison with available data on Gc subtypes in non-Jews. A discriminant and a cluster analysis demonstrated that in their Gc subtype frequencies European and non-European Jews resemble the populations of the areas where they lived before immigrating to Israel. A possible explanation for this resemblance, which is seen in some and not seen in other genetic markers in Jews, is suggested here to be connected with the function of Gc as a vitamin D-binding protein.

Ethnicity↗
PubMedDate not supplied

Population explosion and population control programmes in Bangladesh: an overview.

"The authors discuss in detail efforts made by [the] Bangladesh Government to control its population through planned efforts since 1953. Covering persistent setbacks and reasons thereof in governmental efforts, the authors highlight shifts in policies and strategy.... The [government family planning] programme provides a wide range of contraceptive choice to eligible couples in a manner as acceptable and convenient as possible to the client. The programme is totally voluntary and the government is firmly opposed to coercion or pressure on couples to accept contraception. As a strategy, the programme has integrated health and [family planning] while various ministries have attempted to encourage the acceptance of low-fertility behaviour through socio-economic incentives and educational motivation programmes."

Asia↗
PubMed1981

Occupationally related lead exposure in the general population. A population study of 40-year-old men.

Eighty-eight percent of all 40-year-old male residents of four suburban municipalities of Copenhagen County were examined for the lead concentration in their blood and interviewed regarding job category and place of work. Of the 504 men, 482 were currently employed, 18 were unemployed, and 4 were pensioners. The total median blood lead level was 13 micrograms/100 ml (0.6 mumol/l). Men employed in construction, industrial production, and transportation had the highest lead levels, while very low concentrations were found among pensioners and farmers. Blue-collar works had higher blood lead results than white-collar workers. Very high levels were found in two men employed at a secondary lead smelter, but otherwise increases in lead concentrations were comparatively small. However, the occupationally related, increased blood lead levels identified in this population contributed significantly to normal "background" levels.

Adult↗
PubMed1976

[Prevalence of antibodies to A/New Jersey/76, A/Victoria/3/75 and B/Hong Kong/5/72 influenza viruses in the population of Milan examined in the late spring of 1976 and evaluation of the past experience of the same population with probable agent of the 1918-20 pandemics].

Hemagglutination inhibiting antibodies (h.i.a.) to influenza viruses A/New Jersey/76, A/Victoria/3/75 and B/Hong Kong/5/72 were titrated in 227 serum samples collected in Milan in the late spring 1976 from healthy subjects of 0 to 90 years of age. In 185 of these neuraminidase-inhibiting antibodies (n.i.a.) for the type A strains were also titrated. Subjects up to 40 years of age lack h.i.a. to A/New Jersey/76 strain; antibody levels equal to or greater than 1:40 are occasionally present in the 41-50 year group and the incidence rises to 75% and more after 60 years. N.i.a. are absent in the sera from persons of 0-30 years and titers equal to or greater than 1:100 were found only in the age group over 40. Of the sera examined 44% is lacking in h.i.a. to A/Victoria/3/75 strain and antibodies at protective levels were found in 14% of the subjects, usually among the youngest (0-15 years) and the elderly (over 60 years). N.i.a. for this strain are present in 40% of the samples and 10% have titers equal to or greater than 1.100. Half of the sera under test has h.i.a. to B/Hong Kong/5/72 strain, but only 19% with titers equal to or greater than 1:40. The age distribution of h.i. and n.i. antibodies to A/New Jersey/76 virus suggests that strains antigenically related to the swine virus were widespread in our population until about 1929. The presence of n.i.a., but not of h.i.a. in subjects born between 1935 and 1946 supports the hypothesis of cross-reaction between the neuraminidases of the swine and of the A-O strains.

Adolescent↗
PubMed1999

[Population study of antibodies to some potential pathogens of spondyloarthopathies: the study of the Chukotka population].

The paper presents the results of the study of specific immune response stimulated by some enterobacteria in populations with high incidence of HLA-B27. A, M and G antibodies to Yersinia, Clebsiella, Salmonella and Campilobacter were studied on 292 plasma samples. The levels of the antibodies varied with anthropological parameters of the examinees (gender, age, nationality). The presence of the gene HLA-B27 in the genotype levels gender dimorphism of the specific humoral immune response. This may be of importance in pathogenesis of spondyloarthropathies which occur more frequently in men.

Adolescent↗
PubMed2000

Population genetics of nine STR loci in two populations from Brazil.

The Short Tandem Repeats (STRs) D3S1358, HUMvWA31/A, HUMFIBRA/FGA, D8S 1179, D2S11, D18S51, D5S818, D13S317, and D7S820 were studied in two Brazilian populations (from Amazonia and S. Paulo) using the "AmpF1 STR Profiler Plus PCR Amplification Kit." The nine loci showed a combined discrimination power greater than 0.9999999999 and a chance of exclusion of 0.9999.

Brazil↗
PubMed1978

[Medico-genetic study of the population of Uzbekistan. IV. Medico-genetic description of the population of 4 villages of the Urgut district of the Samarkand region].

The data about the incidence of hereditary diseases and those with genetic predispositions which received after subtotal medico-genetical examination of the inhabitants of 4 villages in the Urgut district of the Samarkand province are presented. 848 inhabitants (348 adults and 464 children aged 7--16 years) are examined. The nosological profile of the morbidity and spectrum of the Mendelian diseases in the population is evaluated. The integrative estimate of load of the detrimental (non-lethal) genes is about 0.166 per individual.

Adult↗
PubMed1979

[Medico-genetic study of the population of Uzbekistan. VI. Hereditary pathology among the populations of 4 regions of the Kashkadarinskaia area].

The screening for families burdened with multiple cases of non-infectious diseases, the diagnostic of those diseases and the investigation of relations between the population structure and the distribution of hereditary diseases in 4 districts of the Kashkadarja province were carried out. On the basis of the data obtained the load of excessive hereditary diseases was calculated and nosological spectrum was described; it included more than 30 different diseases. The study of spatial distribution of recessive diseases has shown that the load of hereditary diseases may be accounted for the positive assortative matings. The high level of interpopulation migration prevents from the local accumulation of a certain hereditary disease.

Genes, Dominant↗
PubMed1988

[Sociomedical characteristics of population groups differing in the frequency of alcohol consumption (population research)].

A representative sample of the population of one Moscow district (people aged 35-64) was studied. All the examined subjects were asked, how often they used alcohol. Only 31.1% of women and 14.3% of men used no alcohol at all. The highest was the percentage of persons using alcohol several times a year: 42.1% of men and 60% of women. Men using alcohol several times a week proved to have arterial hypertension more often than those not using alcohol. Among men aged 55-64 using alcohol several times a week nobody had normal blood pressure. The more alcohol people used, the less they cared for their health and the more rarely they visited a doctor.

Adult↗
PubMed1988

Sodium and blood pressure: positive associations in a north London population with consideration of the methodological problems of within-population surveys.

Blood pressure (BP) and 24-hr urinary sodium (Na) and potassium (K) excretion were measured in 58 men and women aged 40 and above who were selected randomly from the age-sex register of a general practice in North London. All 58 urine collections were reported as complete, but only 28/56 (50%) were classified as 'complete' by the excretion of a biological marker, p-aminobenzoic acid (PABA). Reliability of Na excretion estimated from repeated urine collections was 0.86, indicating that variability of Na excretion within individuals in this middle-aged and elderly population was low. Systolic blood pressure (SBP) was significantly related to 24-hr Na excretion and to 24-hr Na/creatinine ratio. After adjustment for age, sex and body mass index, a SBP-Na regression coefficient of 0.091 mmHg/mmol Na (P = 0.02) was observed. On simple regression analysis, a significant association was also found between diastolic blood pressure and Na (P = 0.04). In the sub-group classified as 'complete' collectors by PABA excretion, BP-Na regression coefficients were larger than in analyses of the sample as a whole. BP was not significantly related to K or Na/K.

4-Aminobenzoic Acid↗
PubMed1987

[A complex medico-genetic study of West Siberian populations. I. Formulation of a problem. Goals and objectives of the study. Population genetic characteristics of Northern Khanty].

Purposes and tasks of the complex medical and genetic study of West-Siberian inhabitants were formulated. Demographic parameters for the North Khanty inhabitants, such as size, dynamics of the tertiary sex ratio, marriage structure and migration processes were presented. Mating and intrapopulation migration patterns are determined by spatial subdivision, because of the vast territory and the traditional way of life, and by isolation by distance. Index of the isolocal endogamy equals to 0.364. The portion of mixed marriages is 22.7% and that of the gametic contribution of immigrants - 7.3%. Inbreeding coefficient by isonymy is 0.00097. Effective population size of the five subpopulations studied as a whole is 25% of their total number.

Consanguinity↗
PubMed1986

[Genetic and ecological study of aboriginal populations of northeastern Siberia. I. Gm-haplotypes and their frequency in 10 chukchi populations. Genetic structure of reindeer chukchi].

G1m (z, a, x, f) and G3m (g, b0, b1, b3, b5, s, t) allotypes were tested in 1079 Chukchi inhabitants of interior Chukotka and adjacent Kamchatka. Genetic variation at this particular locus is provided by the presence of three haplotypes, namely, za;g, zax;g and za;bO35st, revealed with mean frequencies of 0.748, 0.089 and 0.154, respectively. Traces of Caucasian Gm (f;bO135) haplotype were observed in 9 of 10 populations studied. Judging from its frequency in the whole group (0.009), European admixture in Reindeer Chukchi did not exceed 1.3%. Analysis of covariance and variance matrices containing gene frequencies for 11 polymorphic loci revealed the aspects of genetic structure. Simultaneously, the action of systematic versus nonsystematic pressure was also evaluated and interpreted in the light of historical and ecological events.

Asian People↗