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Sample records for chaetocnema pulicaria populations

  1. Temporal distribution of Chaetocnema pulicaria (Coleoptera: Chrysomelidae) populations in Iowa.

    Science.gov (United States)

    Esker, P D; Obrycki, J; Nutter, F W

    2002-08-01

    In 1999 and 2000, yellow sticky cards and sweep net samples were used to document the occurrence of an overwintering adult generation of Chaetocnema pulicaria Melsheimer, corn flea beetle, followed by two distinct populations peaks during the growing season in Iowa Emergence of the overwintering adult generation started in mid-April and continued until early June in both years, with populations as high as 45 +/- 7.9 per 10 sweeps. Periods that ranged from 14 to 32 d were observed in 1999 and 2000 when C. pulicaria was not found following the overwintering generation. The first summer peak of C pulicaria was observed between the end of June into the middle of July, with the highest observed peak at 16.70 +/- 1.42 C. pulicaria per 10 sweeps in cornfields. The second summer peak of C pulicaria was observed between the middle into early September, with populations as high as 27.80 +/- 2.76 C. pulicaria per 10 sweeps. During the growing season, more C. pulicaria were caught on yellow sticky cards originating from soybean borders than from grass borders. There were significantly greater numbers of C. pulicaria on yellow sticky cards located in grass borders adjacent to cornfields at the end of the growing season, compared with yellow sticky cards located within cornfields, indicating the movement of C. pulicaria from the cornfield back into the grass borders at the end of the growing season. In 2000, from August to the end of the corn growing season, significantly more C. pulicaria were found in grass borders than in the cornfields. Based on this new quantitative information, planting time could be altered to avoid the emergence of the overwintering generation of C. pulicaria. In addition, knowledge concerning the seasonalities of the first and second population peaks of C pulicaria during the corn growing season could be used to recommend optimal timing for foliar-applied insecticide applications. This new knowledge concerning the seasonal dynamics of C pulicaria will

  2. Temporal distribution of Chaetocnema pulicaria (Coleoptera: Chrysomelidae) populations in Iowa.

    Science.gov (United States)

    Esker, P D; Obrycki, J; Nutter, F W

    2002-08-01

    In 1999 and 2000, yellow sticky cards and sweep net samples were used to document the occurrence of an overwintering adult generation of Chaetocnema pulicaria Melsheimer, corn flea beetle, followed by two distinct populations peaks during the growing season in Iowa Emergence of the overwintering adult generation started in mid-April and continued until early June in both years, with populations as high as 45 +/- 7.9 per 10 sweeps. Periods that ranged from 14 to 32 d were observed in 1999 and 2000 when C. pulicaria was not found following the overwintering generation. The first summer peak of C pulicaria was observed between the end of June into the middle of July, with the highest observed peak at 16.70 +/- 1.42 C. pulicaria per 10 sweeps in cornfields. The second summer peak of C pulicaria was observed between the middle into early September, with populations as high as 27.80 +/- 2.76 C. pulicaria per 10 sweeps. During the growing season, more C. pulicaria were caught on yellow sticky cards originating from soybean borders than from grass borders. There were significantly greater numbers of C. pulicaria on yellow sticky cards located in grass borders adjacent to cornfields at the end of the growing season, compared with yellow sticky cards located within cornfields, indicating the movement of C. pulicaria from the cornfield back into the grass borders at the end of the growing season. In 2000, from August to the end of the corn growing season, significantly more C. pulicaria were found in grass borders than in the cornfields. Based on this new quantitative information, planting time could be altered to avoid the emergence of the overwintering generation of C. pulicaria. In addition, knowledge concerning the seasonalities of the first and second population peaks of C pulicaria during the corn growing season could be used to recommend optimal timing for foliar-applied insecticide applications. This new knowledge concerning the seasonal dynamics of C pulicaria will

  3. Trap height and orientation of yellow sticky traps affect capture of Chaetocnema pulicaria (Coleoptera: Chrysomelidae).

    Science.gov (United States)

    Esker, P D; Obrycki, J; Nutter, F W

    2004-02-01

    Field studies were conducted in Iowa during 2001 and 2002 to determine the optimal sampling height and orientation for using yellow sticky cards to monitor populations of Chaetocnema pulicaria Melsheimer, the vector of the bacterial pathogen Pantoea stewartii subsp, stewartii, the causal organism of Stewart's disease of corn, Zea mays L.. Sticky cards were placed at five different heights (0.15, 0.30, 0.45, 0.60, and 0.90 m) and three orientations (horizontal, vertical, and 30 degree angle) at three locations (Ames, Crawfordsville, and Sutherland) in 2001 and two locations (Crawfordsville and Johnston) in 2002. No statistical differences were observed among the placement combinations for individual sampling periods or for the total number of C. pulicaria captured in 2001. In 2002, the 0.30 m and vertical cards captured significantly (1.1-35 times) more C. pulicaria than any other placement combination during sampling throughout August at both Crawfordsville and Johnston. Also, the cumulative number of C. pulicaria captured by the 0.30 m and vertical cards was significantly higher than all other placement combinations. This information is important in the development of sampling protocols to aid growers in making management decisions. These management decisions include where and when to apply foliar insecticides during the corn growing season to control C. pulicaria populations, thereby reducing the risk for Stewart's disease of corn. PMID:14998138

  4. Trap height and orientation of yellow sticky traps affect capture of Chaetocnema pulicaria (Coleoptera: Chrysomelidae).

    Science.gov (United States)

    Esker, P D; Obrycki, J; Nutter, F W

    2004-02-01

    Field studies were conducted in Iowa during 2001 and 2002 to determine the optimal sampling height and orientation for using yellow sticky cards to monitor populations of Chaetocnema pulicaria Melsheimer, the vector of the bacterial pathogen Pantoea stewartii subsp, stewartii, the causal organism of Stewart's disease of corn, Zea mays L.. Sticky cards were placed at five different heights (0.15, 0.30, 0.45, 0.60, and 0.90 m) and three orientations (horizontal, vertical, and 30 degree angle) at three locations (Ames, Crawfordsville, and Sutherland) in 2001 and two locations (Crawfordsville and Johnston) in 2002. No statistical differences were observed among the placement combinations for individual sampling periods or for the total number of C. pulicaria captured in 2001. In 2002, the 0.30 m and vertical cards captured significantly (1.1-35 times) more C. pulicaria than any other placement combination during sampling throughout August at both Crawfordsville and Johnston. Also, the cumulative number of C. pulicaria captured by the 0.30 m and vertical cards was significantly higher than all other placement combinations. This information is important in the development of sampling protocols to aid growers in making management decisions. These management decisions include where and when to apply foliar insecticides during the corn growing season to control C. pulicaria populations, thereby reducing the risk for Stewart's disease of corn.

  5. Endophyte isolate and host grass effects on Chaetocnema pulicaria (Coleoptera: Chrysomelidae) feeding.

    Science.gov (United States)

    Ball, Olivier J P; Gwinn, Kimberly D; Pless, Charles D; Popay, Alison J

    2011-04-01

    Endophytic fungi belonging to the genus Neotyphodium, confer resistance to infected host grasses against insect pests. The effect of host species, and endophtye species and strain, on feeding and survival of the corn flea beetle, Chaetocnema pulicaria Melsheimer (Coleoptera: Chrysomelidae) was investigated. The grass-endophyte associations included natural and artificially derived associations producing varying arrays of common endophyte-related alkaloids or alkaloid groups, peramine, lolitrem B, ergovaline, and the lolines. Preference and nonpreference tests showed that C. pulicaria feeding and survival were reduced by infection of tall fescue with the wild-type strain of N. coenophialum, the likely mechanism being antixenosis rather than antibiosis. In the preference tests, endophyte and host species effects were observed. Of the 10 different Neotyphodium strains tested in artificially derived tall fescue associations, eight strongly deterred feeding by C. pulicaria, whereas the remaining two strains had little or no effect on feeding. Infection of tall fescue with another fungal symbiont, p-endophyte, had no effect. Perennial ryegrass, Lolium perenne L., infected with six strains of endophyte, was moderately resistant to C. pulicaria compared with endophyte-free grass, but four additional strains were relatively inactive. Six Neotyphodium-meadow fescue, Festuca pratensis Huds., associations, including the wild-type N. uncinatum-meadow fescue combination, were resistant, whereas three associations were not effective. Loline alkaloids seemed to play a role in antixenosis to C. pulicaria. Effects not attributable to the lolines or any other of the alkaloids examined also were observed. This phenomenon also has been reported in tests with other insects, and indicates the presence of additional insect-active factors.

  6. Immunofluorescence localization and ultrastructure of Stewart’s wilt disease bacterium Pantoea stewartii in maize leaves and in its flea beetle vector Chaetocnema pulicaria (Coleoptera: Chrysomelidae)

    Science.gov (United States)

    Pantoea stewartii is the causal agent of Stewart's wilt of sweet corn, the most serious bacterial disease of sweet corn and maize in the North-Central and Eastern USA. P. stewartii is transmitted mainly by the corn flea beetle Chaetocnema pulicaria (Coleoptera: Chrysomelidae) and this bacterium is a...

  7. First results on the distribution of Nosema chaetocnemae Yaman et Radek, 2003 (Microspora) in the populations of Chaetocnema tibialis Illiger, 1807 (Coleoptera: Chrysomelidae).

    Science.gov (United States)

    Yaman, Mustafa

    2008-01-01

    In the present study, the first report on the distribution of Nosema chaetocnemae infection of Chaetocnema tibialis populations in Turkey is given. Of the 1751 beetles collected from ten provinces, 193 were infected by the parasite. The infection average was 11.02% in Turkey. Nosema infection was found in C. tibialis adults from two (Samsun and Trabzon) of the ten provinces studied. In eight localities in different regions of Turkey, the infection was not observed. The highest percentage of beetles infected with a Nosema isolate was recorded in Samsun. The infection average in Samsun was 25.20%. The results showed that the infection level of N. chaetocnemae was relatively stable during the observation period between the years 2000-2006.

  8. Geographical and Temporal Dynamics of Chaetocnema Pulicaria and Their Role in Stewart's Disease of Corn in Iowa

    Energy Technology Data Exchange (ETDEWEB)

    Paul David Esker

    2001-05-27

    This thesis investigated the biology and importance of the corn flea beetle vector and its role in the Stewart's disease of corn pathosystem. This was accomplished by determining the number of corn flea beetle generations that occur in Iowa and by quantifying the proportions of those populations found to be infested with the causal agent of Stewart's disease, pantoea stewartii. In addition, a preliminary study was conducted to determine how soil temperature was influenced by air temperature and how this may be applied to forecasting for Stewart's disease of corn. Research using yellow sticky cards and sweep netting demonstrated that there are overwintering, first, and second field generations of the corn flea beetle in Iowa. It was also observed that there was a period during June of both 1999 and 2000 when corn flea beetles were not found, which is important new management information. This research has also demonstrated that the incidence of P. stewartii-infested corn flea beetles can be monitored by ELISA testing and that the incidence fluctuates greatly throughout the corn growing season. The initial level of inoculum (P. stewartii-infested corn flea beetles in the adult overwintering generation) does not remain static during the spring as was previously hypothesized. This signals that additional research is needed concerning the mechanisms of fluctuation in the proportion of beetles infested with P. stewartii.

  9. Incidence of diapause varies among populations of Daphnia pulicaria.

    Science.gov (United States)

    Cáceres, Carla E; Tessier, Alan J

    2004-11-01

    Dormancy is a common way in which organisms survive environmental conditions that would be lethal to the active individual. However, while dormant, individuals forego reproduction. Hence theory suggests an optimal time in which to enter dormancy, depending on risks associated with both remaining active and entering dormancy. When these relative risks differ among habitats, dormancy strategies are predicted to vary as well. For freshwater zooplankton, it has been suggested that sensitivity to the cues that initiate dormancy should be selected against when females have the opportunity to remain in the water column year round. We tested this prediction with 12 populations of lake-dwelling Daphnia pulicaria (Crustacea: Cladocera). Differences among lakes in basin morphometry, predators and resources create a gradient of risk for Daphnia in the water column. Some populations persist in high numbers year round while others are abundant only in spring. We used this difference in persistence ability as an estimate of risk in the water-column. For 3 years of field sampling we found consistent differences among the lake populations in the incidence of dormancy. In some populations, only a small fraction of females switched to producing dormant eggs each year whereas in others the majority of eggs produced in the late spring were dormant. In general, populations that experienced predictably low abundances in the active form exhibited higher incidence of dormancy than did populations that persisted in high abundance year round, but there were exceptions. Our results confirm that the incidence of dormancy varies considerably among populations in a fashion consistent with general theory, but suggest that persistence in the water column is not the sole predictor of the diapause strategy found in any particular lake.

  10. Geographical and Temporal Dynamics of Chaetocnema Pulicaria Populations and Their Role in Stewart's Disease of Corn in Iowa

    Energy Technology Data Exchange (ETDEWEB)

    Paul David Esker

    2001-05-01

    This thesis is organized into five chapters. Chapter 1 is the introduction and justification, chapters 2 and 3 are journal papers, chapter 4 is a preliminary analysis of winter environmental variables and their use in forecasting for Stewart's disease of corn, and chapter 5 is general conclusions and discussion. References can be found at the end of each chapter, except chapter 5 and are specific to that chapter.

  11. Correlated evolution of life-history with size at maturity in Daphnia pulicaria: patterns within and between populations.

    Science.gov (United States)

    Baer, Charles F; Lynch, Michael

    2003-04-01

    Explaining the repeated evolution of similar sets of traits under similar environmental conditions is an important issue in evolutionary biology. The extreme alternative classes of explanations for correlated suites of traits are optimal adaptation and genetic constraint resulting from pleiotropy. Adaptive explanations presume that individual traits are free to evolve to their local optima and that convergent evolution represents particularly adaptive combinations of traits. Alternatively, if pleiotropy is strong and difficult to break, strong selection on one or a few particularly important characters would be expected to result in consistent correlated evolution of associated traits. If pleiotropy is common, we predict that the pattern of divergence among populations will consistently reflect the within-population genetic architecture. To test the idea that the multivariate life-history phenotype is largely a byproduct of strong selection on body size, we imposed divergent artificial selection on size at maturity upon two populations of the cladoceran Daphnia pulicaria, chosen on the basis of their extreme divergence in body size. Overall, the trajectory of divergence between the two natural populations did not differ from that predicted by the genetic architecture within each population. However, the pattern of correlated responses suggested the presence of strong pleiotropic constraints only for adult body size and not for other life-history traits. One trait, offspring size, appears to have evolved in a way different from that expected from the within-population genetic architecture and may be under stabilizing selection.

  12. Both costs and benefits of sex correlate with relative frequency of asexual reproduction in cyclically parthenogenic Daphnia pulicaria populations.

    Science.gov (United States)

    Allen, Desiree E; Lynch, Michael

    2008-07-01

    Sexual reproduction is generally believed to yield beneficial effects via the expansion of expressed genetic variation, which increases the efficiency of selection and the adaptive potential of a population. However, when nonadditive gene action is involved, sex can actually impede the adaptive progress of a population. If selection promotes coupling disequilibria between genes of similar effect, recombination and segregation can result in a decrease in expressed genetic variance in the offspring population. In addition, when nonadditive gene action underlies a quantitative trait, sex can produce a change in trait means in a direction opposite to that favored by selection. In this study we measured the change in genotypic trait means and genetic variances across a sexual generation in four populations of the cyclical parthenogen Daphnia pulicaria, which vary predictably in their incidence of sexual reproduction. We show that both the costs and benefits of sex, as measured by changes in means and variances in life-history traits, increase substantially with decreasing frequency of sex.

  13. Correlated responses to clonal selection in populations of Daphnia pulicaria: mechanisms of genetic correlation and the creative power of sex.

    Science.gov (United States)

    Dudycha, Jeffry L; Snoke-Smith, Margaret; Alía, Ricardo

    2013-02-01

    Genetic correlations among traits alter evolutionary trajectories due to indirect selection. Pleiotropy, chance linkage, and selection can all lead to genetic correlations, but have different consequences for phenotypic evolution. We sought to assess the mechanisms contributing to correlations with size at maturity in the cyclic parthenogen Daphnia pulicaria. We selected on size in each of four populations that differ in the frequency of sex, and evaluated correlated responses in a life table. Size at advanced adulthood, reproductive output, and adult growth rate clearly showed greater responses in high-sex populations, with a similar pattern in neonate size and r. This pattern is expected only when trait correlations are favored by selection and the frequency of sex favors the creation and demographic expansion of highly fit clones. Juvenile growth and age at maturity did not diverge consistently. The inter-clutch interval appeared to respond more strongly in low-sex populations, but this was not statistically significant. Our data support the hypothesis that correlated selection is the strongest driver of genetic correlations, and suggest that in organisms with both sexual and asexual reproduction, adaptation can be enhanced by recombination.

  14. Environmental gradients structure Daphnia pulex × pulicaria clonal distribution.

    Science.gov (United States)

    Pantel, J H; Juenger, T E; Leibold, M A

    2011-04-01

    The rarity of eukaryotic asexual reproduction is frequently attributed to the disadvantage of reduced genetic variation relative to sexual reproduction. However, parthenogenetic lineages that evolved repeatedly from sexual ancestors can generate regional pools of phenotypically diverse clones. Various theories to explain the maintenance of this genetic diversity as a result of environmental and spatial heterogeneity [frozen niche variation (FNV), general-purpose genotype] are conceptually similar to community ecological explanations for the maintenance of regional species diversity. We employed multivariate statistics common in community ecological research to study population genetic structure in the freshwater crustacean, Daphnia pulex × pulicaria. This parthenogenetic hybrid arose repeatedly from sexual ancestors. Daphnia pulex × pulicaria populations harboured substantial genetic variation among populations and the clonal composition at each pond corresponded to nutrient levels and invertebrate predator densities. The interclonal selection process described by the FNV hypothesis likely structured our D. pulex × pulicaria populations.

  15. Clerodane diterpenoids from Pulicaria wightiana.

    Science.gov (United States)

    Das, Biswanath; Ravinder Reddy, M; Ramu, R; Ravindranath, N; Harish, H; Ramakrishna, K V S; Koteswar Rao, Y; Harakishore, K; Murthy, U S N

    2005-03-01

    Five clerodane diterpenoids have been isolated from the aerial parts of Pulicaria wightiana along with 3'5,6-trihydroxy-3,4',7-trimethoxyflavone and 2-methyl-5-hydroxy-chroman-4-one. The structures and stereochemistry of the compounds were established from spectral (mainly 1D and 2D NMR) studies. The last two compounds were not reported earlier from this plant. The antibacterial activity of the diterpenoids were studied.

  16. Cryptic intercontinental colonization in water fleas Daphnia pulicaria inferred from phylogenetic analysis of mitochondrial DNA variation.

    Science.gov (United States)

    Marková, Silvia; Dufresne, France; Rees, David J; Cerný, Martin; Kotlík, Petr

    2007-07-01

    The water fleas of the Daphnia pulex complex play a key role in freshwater ecosystems throughout the northern hemisphere. Despite the fact that they have been the subject of study for numerous biological disciplines, their phylogeny and species delimitation remain controversial. We used DNA sequence variation of the mitochondrial ND5 gene to reconstruct the phylogenetic relationships of D. pulicaria Forbes, a widespread member of this complex from North America and Europe. Populations from the two continents respectively split into two evolutionary lineages, Eastern Nearctic and European, which each belong to another main clade within the D. pulex complex (the pulicaria and tenebrosa groups, respectively). Unexpectedly, melanin and carotenoid pigmented D. pulicaria populations from European high-mountain lakes were not allied with the transparent populations inhabiting the same lakes and the lowland ponds and reservoirs throughout Europe, but were included with the samples from Canada and Greenland in the Eastern Nearctic lineage. Until now populations belonging to this lineage were known only from Canada and North Atlantic islands, but not from mainland Europe. Independent data from microsatellite markers supported the genetic distinctiveness of the sympatric carotenoid pigmented and transparent populations and suggested that they may have undergone transition to obligate parthenogenesis, possibly as a consequence of past introgressive hybridization. Two different taxa are therefore confused under the name D. pulicaria in Europe. The close phylogenetic relationships of European populations with those from Canada and Greenland suggest that the Nearctic lineage is of recent origin in Europe via intercontinental dispersal from the North America. It has evolved melanin and carotenoid pigmentation as adaptations against the UV light stress, which enable it to share habitat occupied by the transparent European species. The Nearctic D. pulicaria thus provides a new model

  17. Contrasting migration behaviour of Daphnia pulicaria and D. galeata × hyalina, in avoidance of predation by 0+perch (Perca fluviatilis)

    NARCIS (Netherlands)

    Flik, B.J.G.; Vijverberg, J.

    2003-01-01

    In spring and early summer, a small population of the large-bodied Daphnia pulicaria coexists with a much larger population of the medium-sized hybrid Daphnia galeata × hyalina in the epilimnion of Lake Maarsseveen (The Netherlands). When large shoals of juvenile perch (Perca fluviatilis) appear in

  18. Antibacterial activity of Pulicaria dysenterica extracts.

    Science.gov (United States)

    Nickavar, Bahman; Mojab, Faraz

    2003-06-01

    Aqueous, methanolic and chloroformic extracts of Pulicaria dysenterica aerial parts were tested for their antibacterial activity using the disc-diffusion assay technique. The methanolic extract was found to be the most effective extract against three out of six tested bacteria. All of the extracts were active against Vibrio cholera.

  19. Characterization of genome-wide SNPs for the water flea Daphnia pulicaria generated by genotyping-by-sequencing (GBS)

    DEFF Research Database (Denmark)

    Muñoz, Joaquín; Chaturvedi, Anurag; De Meester, Luc;

    2016-01-01

    populations. We report a unique resource of novel Single Nucleotide Polymorphic (SNP) markers for Daphnia pulicaria using the reduction in genomic complexity with the restriction enzymes approach, genotyping-by-sequencing. Using the genome of D. pulex as a reference, SNPs were scored for 53 clones from five...

  20. Diversity in the reproductive modes of European Daphnia pulicaria deviates from the geographical parthenogenesis.

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    France Dufresne

    Full Text Available BACKGROUND: Multiple transitions to obligate parthenogenesis have occurred in the Daphnia pulex complex in North America. These newly formed asexual lineages are differentially distributed being found predominantly at high latitudes. This conforms to the rule of geographical parthenogenesis postulating prevalence of asexuals at high latitudes and altitudes. While the reproductive mode of high-latitude populations is relatively well studied, little is known about the reproduction mode in high altitudes. This study aimed to assess the reproductive mode of Daphnia pulicaria, a species of the D. pulex complex, from high altitude lakes in Europe. METHODOLOGY/PRINCIPAL FINDINGS: Variation at eight microsatellite loci revealed that D. pulicaria from the High Tatra Mountains (HTM had low genotype richness and showed excess of heterozygotes and significant deviations from Hardy-Weinberg expectations, and was thus congruent with reproduction by obligate parthenogenesis. By contrast, populations from the Pyrenees (Pyr were generally in Hardy-Weinberg equilibrium and had higher genotypic richness, suggesting that they are cyclic parthenogens. Four lakes from lowland areas (LLaP had populations with an uncertain or mixed breeding mode. All D. pulicaria had mtDNA ND5 haplotypes of the European D. pulicaria lineage. Pyr were distinct from LLaP and HTM at the ND5 gene. By contrast, HTM shared two haplotypes with LLaP and one with Pyr. Principal Coordinate Analysis of the microsatellite data revealed clear genetic differentiation into three groups. HTM isolates were intermediate to Pyr and LLaP, congruent with a hybrid origin. CONCLUSION/SIGNIFICANCE: Inferred transitions to obligate parthenogenesis have occurred only in HTM, most likely as a result of hybridizations. In contrast to North American populations, these transitions do not appear to involve meiosis suppressor genes and have not been accompanied by polyploidy. The absence of obligate parthenogenesis

  1. Revision of Chaetocnema semicoerulea species-group (Coleoptera: Chrysomelidae: Galerucinae: Alticini) in China, with descriptions of three new species

    Science.gov (United States)

    Chinese species of Chaetocnema semicoerulea group are revised and 3 new species described as new: C. salixis n.sp., C. yulongensis n.sp. and C. deqinensis n.sp. A key to all 5 species of this group occurring in China and the illustrations of habitus and genitalia are provided. A map of species distr...

  2. Revision of the Chinese Chaetocnema picipes species-group (Coleoptera: Chrysomelidae: Galerucinae: Alticini), with descriptions of three new species

    Science.gov (United States)

    Chaetocnema picipes species-group is revised in China. It contains 5 species including 3 new species: C. cheni n.sp., C. constricta n.sp. and C. kingpinensis n.sp.. The lectotype of C. fortecostata is designated. A key to all known species of this group from China and illustrations of habitus and ge...

  3. Temporal Dynamics of Corn Flea Beetle Populations Infested with Pantoea stewartii, Causal Agent of Stewart's Disease of Corn.

    Science.gov (United States)

    Esker, P D; Nutter, F W

    2003-02-01

    ABSTRACT In order to better understand the epidemiology of the Stewart's disease of corn pathosystem, quantitative information concerning the temporal dynamics of the amount of pathogen inoculum present in the form of Pantoea stewartii-infested corn flea beetles (Chaetocnema pulicaria) is needed. Temporal changes in the proportion of P. stewartii-infested corn flea beetle populations were monitored by testing individual corn flea beetles for the presence of P. stewartii using a peroxidase-labeled, enzyme-linked immunosorbent assay. Approximately 90 corn flea beetles were collected each week from seven locations in Iowa from September 1998 through October 2000 using sweep nets. The proportion of P. stewartii-infested beetles at the end of the 1998 growing season ranged from 0.04 to 0.19. In spring 1999, the proportion of overwintering adult corn flea beetles infested with P. stewartii ranged from 0.10 to 0.11 and did not differ significantly from the previous fall based on chi(2). During the 1999 corn-growing season, the proportion of infested corn flea beetles ranged from 0.04 to 0.86, with the highest proportions occurring in August. In fall 1999, the proportion of beetles infested with P. stewartii ranged from 0.20 to 0.77. In spring 2000, the proportion of overwintering adult corn flea beetles infested with P. stewartii ranged from 0.08 to 0.30; these proportions were significantly lower than the proportions observed in fall 1999 at Ames, Chariton, and Nashua. During the 2000 corn-growing season, the proportion of P. stewartii-infested corn flea beetles ranged from 0.08 to 0.53, and the highest observed proportions again occurred in August. Corn flea beetle populations sampled in late fall 2000 had proportions of infested beetles ranging from 0.08 to 0.20. This is the first study to quantify the temporal population dynamics of P. stewartii-infested C. pulicaria populations in hybrid corn and provides new quantitative information that should be useful in

  4. Guaianolide sesquiterpenes from Pulicaria crispa (Forssk.) Oliv.

    Science.gov (United States)

    Stavri, Michael; Mathew, K T; Gordon, Andrew; Shnyder, Steven D; Falconer, Robert A; Gibbons, Simon

    2008-06-01

    A phytochemical study of the asteraceous herb Pulicaria crispa (Forssk.) Oliv. resulted in the characterisation of three guaianolide sesquiterpenes, 2alpha,4alpha-dihydroxy-7alphaH,8alphaH,10alphaH-guaia-1(5),11(13)-dien-8beta,12-olide (1), 1alpha,2alpha-epoxy-4beta-hydroxy-5alphaH,7alphaH,8alphaH,10alphaH-guaia-11(13)-en-8beta,12-olide (2) and 5,10-epi-2,3-dihydroaromatin (3). The structures were assigned on the basis of extensive 1 and 2D NMR experiments. Compound 3 exhibited weak antimycobacterial activity against Mycobacterium phlei with a minimum inhibitory concentration of 0.52 mM and cytotoxicity (IC50 of 5.8+/-0.2 microM) in a human bladder carcinoma cell line, EJ-138.

  5. New clerodane diterpenoids from the aerial parts of Pulicaria wightiana.

    Science.gov (United States)

    Das, Biswanath; Ramu, Ravirala; Venkateswarlu, Katta; Rao, Yerra Koteswara; Reddy, Majjigapu Ravinder; Ramakrishna, Kallaganti Venkata Siva; Harakishore, Kankipati; Murty, Upadhayula Suryanarayana

    2006-02-01

    Two new ent-clerodane-type diterpenoids, compounds 1 and 2, were isolated from the aerial parts of Pulicaria wightiana, together with three known constituents. Their structures were established based on spectroscopic data, and their antibacterial activities were evaluated (Table 2).

  6. Gnapholide: a new guaiac-dimer from Pulicaria gnaphalodes (Asteraceae).

    Science.gov (United States)

    Ali, Muhammad Shaiq; Jahangir, Muhammad; Uzair, Syed Shah; Erian, Ayman Wahba; Tareen, Rasool Bakhsh

    2002-06-01

    The ethyl acetate soluble part of the chloroform extract of Pulicaria gnaphalodes belonging to the family Asteraceae afforded a new sesquiterpene-dimer of guaiane class named as gnapholide and anabsinthin of the same skeleton. The structures of both the compounds were elucidated with the aid of spectroscopic techniques including 2D NMR.

  7. Chemical composition and leishmanicidal activity of Pulicaria gnaphalodes essential oil

    Directory of Open Access Journals (Sweden)

    G. Asghari

    2014-10-01

    Full Text Available Background and objectives: Several natural compounds have been identified for the treatment ofleishmaniasis. Due to a few safe drugs and the side effects caused by available chemotherapy, some new drugs for treatment of leishmaniasis are requested.  The genus Pulicaria (Asteraceae is represented in the flora of Iran by five species. Phytochemical studies on Pulicaria species have revealed some flavonoids and terpenoids with leishmanicidal activity. In the present investigation chemical composition and leishmanicidal activity of Pulicaria gnaphalodes essential oil have been studied. Methods: The essential oil of the aerial parts of the plant was obtained by Clevenger apparatus and was analyzed by GC/MS. Antileishmanil activity was assessed against promastigoes of Leishmania major. Results:The major components from P. gnaphalodes essential oil have been reported to be geraniol, 1,8-cineole, chrysanthenone, α-pinene, chrystanthenone, α-terpineol and filifolone. The alcohol monoterpenes with contribution of 25.04% constituted the major portion of the essential oil, while hydrocarbon monoterpenes and hydrocarbon sesquiterpenes with contribution of 7.08% and 2.38%, respectively occupied the next rates.In the present experiment the essential oil of P. gnaphalodes progressively inhibited Leishmania major growth in concentrations ranging from 0.125 to 50 µL/mL (parasite culture in 24 h. The essential oil at 50 µL/mL eliminated the promastigotes at the beginning of treatment. It showed antileishmanial activity in concentration of 1.06 µL/mL and destroyed all parasits in 24 h.  Conclusion: Pulicaria gnaphalodes antileishmanial activity, could suggest the species and constituents as possible lead structures for antileishmanial drug discovery.

  8. Variation in toxicity of a current-use insecticide among resurrected Daphnia pulicaria genotypes.

    Science.gov (United States)

    Simpson, Adam M; Jeyasingh, Punidan D; Belden, Jason B

    2015-04-01

    This study examined how genotypes of Daphnia pulicaria from a single population, separated by thousands of generations of evolution in the wild, differ in their sensitivity to a novel anthropogenic stressor. These genotypes were resurrected from preserved resting eggs isolated from sediments belonging to three time periods: 2002-2008, 1967-1977, and 1301-1646 A.D. Toxicity of the organophosphate insecticide chlorpyrifos was determined through a series of acute toxicity tests. There was a significant dose-response effect in all genotypes studied. Moreover, significant variation in toxicity among genotypes within each time period was detected. Importantly, a significant effect of time period on sensitivity to chlorpyrifos was found. Analysis of the median effect concentrations (EC50s) for genotypes within each time period indicated that the 1301-1646 genotypes were 2.7 times more sensitive than the 1967-1977 genotypes. This trend may be partially explained by microevolutionary shifts in response to cultural eutrophication.

  9. Variations in lipophilic and vacuolar flavonoids among European Pulicaria species.

    Science.gov (United States)

    Williams, Christine A; Harborne, Jeffrey B; Greenham, Jenny R; Grayer, Renée J; Kite, Geoffrey C; Eagles, John

    2003-09-01

    Four European Pulicaria species, P. odora, P. paludosa, P. sicula and P. vulgare, were analysed for their surface and vacuolar constituents for comparison with previous data obtained for P. dysenterica. Each species had a distinct flavonoid pattern with notable differences between leaf and inflorescence. 6-Hydroxyflavonols were the major lipophilic components in all of the species and tissues except in the leaves of P. paludosa and P. vulgare, where scutellarein 6-methyl ether was the main constituent. In the leaves of P. sicula a more unusual flavone, 6-hydroxyluteolin 5,6,7,3',4'-pentamethyl ether, was a major component. Pulicaria odora was distinguished by the presence of a series of methylated 6-hydroxykaempferol derivatives including a 3,5,6,7,4'-pentamethyl ether. Quercetagetin hexamethyl ether occurred in both tissues of P. sicula together with the 3,7,3,4'-tetra methyl ether and other quercetagetin derivatives, which were 5-methylated. Quercetagetin 3,7,3'-methyl ether was present in all species except P. odora. Flavonol glucuronides were characteristic vacuolar constituents of all the taxa studied. Two rare glycosides, patuletin and 6-hydroxykaempferol 6-methyl ether 7-glucuronides were identified in the inflorescence of P. odora. Pulicaria vulgaris, a rare plant of southern England, had the vacuolar flavonoid profile most similar to the other more abundant British plant, P. dysenterica.

  10. Variation in copper effects on kairomone-mediated responses in Daphnia pulicaria.

    Science.gov (United States)

    DeMille, C M; Arnott, S E; Pyle, G G

    2016-04-01

    Chemical signals play an integral role in many predator-prey relationships but their effectiveness can be altered by environmental conditions. Prey species can detect predator kairomones, which induce anti-predator defenses. An example of this predator-prey relationship exists between Daphnia spp. and Chaoborus spp.; however, when living in water contaminated with low concentrations of copper (Cu) Daphnia can fail to respond to Chaoborus kairomone and, in turn, become more susceptible to predation. This has implications for Daphnia living in regions with Cu contamination, such as areas where mining activity has resulted in increased levels of metals in the surrounding lakes. We examined kairomone-mediated responses of multiple Daphnia pulicaria clones obtained from 8 lakes in Ontario, Canada, in the absence and presence of environmentally-relevant Cu concentrations. Life history traits and morphological anti-predator defenses were assessed using neonates collected from mothers that were exposed to kairomone and Cu treatments. We found that kairomone-mediated responses and Cu-tolerance varied among D. pulicaria clones. Clones exposed to kairomone, in the absence of Cu additions, had diverse responses, including larger neonates, delayed reproduction, or altered brood size relative to no-kairomone controls. These kairomone-induced responses act as antipredator defense strategies against Chaoborus by preventing predation or stabilizing population growth. When exposed to Cu, two clones were able to respond to kairomone, while four clones no longer induced a response to kairomone. This variation in non-lethal effects of Cu on aquatic organisms suggests that toxicity tests should incorporate multiple genotypes and include predator-prey interactions.

  11. New ent-kaurane diterpenoid dimer from Pulicaria inuloides.

    Science.gov (United States)

    Galala, Amal A; Sallam, Amal; Abdel-Halim, Osama B; Gedara, Sahar R

    2016-11-01

    A new naturally occurring ent-kaurane diterpenoid dimer, 15β, 15'β-oxybis (ent-kaur-16-en-19-oic acid) (1) along with six known compounds, 15β-hydroxy-ent-kaur-16-en-19-oic acid (2), 15β-hydroxy-ent-kaur-16-en-19-oate-β-d-glucopyranoside (3), 6-hydroxykaempferol-3, 7-dimethyl ether (4), quercetagetin 3, 7, 3'-trimethyl ether (5), β-sitosterol (6) and β-sitosterol glucoside (daucosterol) (7) were isolated from the aerial parts of Pulicaria inuloides DC. Compounds 2-5 were isolated for the first time from genus Pulicaria. The structures of compounds 1-7 were established on the basis of extensive 1D and 2D NMR spectroscopic techniques in combination with ESI-MS. The antimicrobial activity of the isolated compounds was evaluated against Staphylococcus aureus, Escherichia coli and Candida albicans. Sulphorhodamine B cytotoxic assay against HepG2 (liver cancer) cell line and ABTS antioxidant assay were carried out.

  12. Predicting chronic copper and nickel reproductive toxicity to Daphnia pulex-pulicaria from whole-animal metabolic profiles.

    Science.gov (United States)

    Taylor, Nadine S; Kirwan, Jennifer A; Johnson, Craig; Yan, Norman D; Viant, Mark R; Gunn, John M; McGeer, James C

    2016-05-01

    The emergence of omics approaches in environmental research has enhanced our understanding of the mechanisms underlying toxicity; however, extrapolation from molecular effects to whole-organism and population level outcomes remains a considerable challenge. Using environmentally relevant, sublethal, concentrations of two metals (Cu and Ni), both singly and in binary mixtures, we integrated data from traditional chronic, partial life-cycle toxicity testing and metabolomics to generate a statistical model that was predictive of reproductive impairment in a Daphnia pulex-pulicaria hybrid that was isolated from an historically metal-stressed lake. Furthermore, we determined that the metabolic profiles of organisms exposed in a separate acute assay were also predictive of impaired reproduction following metal exposure. Thus we were able to directly associate molecular profiles to a key population response - reproduction, a key step towards improving environmental risk assessment and management.

  13. Sesquiterpenoids from Pulicaria canariensis and their cytotoxic activities.

    Science.gov (United States)

    Triana, Jorge; López, Mariana; Pérez, Francisco J; González-Platas, Javier; Quintana, José; Estévez, Francisco; León, Francisco; Bermejo, Jaime

    2005-04-01

    Thirteen new sesquiterpenes, pulicanadiene A (1), B (2), and C (3), pulicanone (4), pulicanol (5), pulicanarals A (6), B (7), and C (8), pulicanadienals A (9) and B (10), pulicanadienol (11), and pulioplopanones A (12) and B (13), and seven known compounds, stigmasterol, ergosterol peroxide, calenduladiol, 7,4'-di-O-methyldihydrokaempferol, 5,7-dihydroxy-3,3',4'-trimethoxyflavone, dihydroquercetin 7,3'-dimethyl ether, and 6,15alpha-epoxy-1beta,4beta-dihydroxyeudesmane, were isolated from Pulicaria canariensis. Compound 4a showed cytotoxicity on the human myeloid leukemia cell line HL-60. The cytotoxicity was caused by induction of apoptosis as determined by microscopy of nuclear changes, activation of caspases, and the cleavage of poly(ADP-ribose) polymerase-1.

  14. Geographical variation in the surface flavonoids of Pulicaria dysenterica.

    Science.gov (United States)

    Williams; Harborne; Greenham

    2000-08-01

    Four chemical races were detected in Pulicaria dysenterica, when sampled within Europe, on the basis of the surface flavonoids present. One race uniquely contained quercetagetin 3,7-dimethyl ether and another 6-hydroxykaempferol 3,4'-dimethyl ether. A third race was based on plants having 6-hydroxykaempferol 3,7-dimethyl ether together with quercetagetin 3,7,3'-trimethyl ether. The fourth race contained the above two compounds, as well as quercetagetin 3,7,3',4'-tetramethyl ether and 6-hydroxykaempferol 3,7,4'-trimethyl ether. These lipophilic constituents were variously present on the surfaces of leaf, ray floret, disc floret and fruit. By contrast, the vacuolar flavonoid of all tissues and all races was uniformly quercetin 3-glucuronide. The kaempferol 3-glucoside previously reported in flowers was not detected. Of the lipophilic flavonoids newly reported from this plant, one 6-hydroxykaempferol 3,7,4'-trimethyl ether is new to nature.

  15. Antioxidant and astroprotective effects of a Pulicaria incisa infusion.

    Science.gov (United States)

    Elmann, Anat; Telerman, Alona; Mordechay, Sharon; Erlank, Hilla; Ofir, Rivka

    2012-01-01

    Oxidative stress is involved in the pathogenesis of neurodegenerative diseases such as Parkinson's and Alzheimer's diseases. Astrocytes, the most abundant glial cells in the brain, protect neurons from reactive oxygen species (ROS) and provide them with trophic support, such as glial-derived neurotrophic factor (GDNF). Thus, any damage to astrocytes will affect neuronal survival. In the present study, an infusion prepared from the desert plant Pulicaria incisa (Pi) was tested for its protective and antioxidant effects on astrocytes subjected to oxidative stress. The Pi infusion attenuated the intracellular accumulation of ROS following treatment with hydrogen peroxide and zinc and prevented the H(2)O(2)-induced death of astrocytes. The Pi infusion also exhibited an antioxidant effect in vitro and induced GDNF transcription in astrocytes. It is proposed that this Pi infusion be further evaluated for use as a functional beverage for the prevention and/or treatment of brain injuries and neurodegenerative diseases in which oxidative stress plays a role.

  16. Green synthesis of silver nanoparticles mediated by Pulicaria glutinosa extract.

    Science.gov (United States)

    Khan, Mujeeb; Khan, Merajuddin; Adil, Syed Farooq; Tahir, Muhammad Nawaz; Tremel, Wolfgang; Alkhathlan, Hamad Z; Al-Warthan, Abdulrahman; Siddiqui, Mohammed Rafiq H

    2013-01-01

    The green synthesis of metallic nanoparticles (NPs) has attracted tremendous attention in recent years because these protocols are low cost and more environmentally friendly than standard methods of synthesis. In this article, we report a simple and eco-friendly method for the synthesis of silver NPs using an aqueous solution of Pulicaria glutinosa plant extract as a bioreductant. The as-prepared silver NPs were characterized using ultraviolet-visible spectroscopy, powder X-ray diffraction, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier-transform infrared spectroscopy. Moreover, the effects of the concentration of the reductant (plant extract) and precursor solution (silver nitrate), the temperature on the morphology, and the kinetics of reaction were investigated. The results indicate that the size of the silver NPs varied as the plant extract concentration increased. The as-synthesized silver NPs were phase pure and well crystalline with a face-centered cubic structure. Further, Fourier-transform infrared spectroscopy analysis confirmed that the plant extract not only acted as a bioreductant but also functionalized the NPs' surfaces to act as a capping ligand to stabilize them in the solvent. The developed eco-friendly method for the synthesis of NPs could prove a better substitute for the physical and chemical methods currently used to prepare metallic NPs commonly used in cosmetics, foods, and medicines.

  17. Antioxidant and Astroprotective Effects of a Pulicaria incisa Infusion

    Directory of Open Access Journals (Sweden)

    Anat Elmann

    2012-01-01

    Full Text Available Oxidative stress is involved in the pathogenesis of neurodegenerative diseases such as Parkinson's and Alzheimer's diseases. Astrocytes, the most abundant glial cells in the brain, protect neurons from reactive oxygen species (ROS and provide them with trophic support, such as glial-derived neurotrophic factor (GDNF. Thus, any damage to astrocytes will affect neuronal survival. In the present study, an infusion prepared from the desert plant Pulicaria incisa (Pi was tested for its protective and antioxidant effects on astrocytes subjected to oxidative stress. The Pi infusion attenuated the intracellular accumulation of ROS following treatment with hydrogen peroxide and zinc and prevented the H2O2-induced death of astrocytes. The Pi infusion also exhibited an antioxidant effect in vitro and induced GDNF transcription in astrocytes. It is proposed that this Pi infusion be further evaluated for use as a functional beverage for the prevention and/or treatment of brain injuries and neurodegenerative diseases in which oxidative stress plays a role.

  18. Volatile constituents of the aerial parts of Pulicaria sicula (L.) Moris growing wild in Sicily: chemotaxonomic volatile markers of the genus Pulicaria Gaertn.

    Science.gov (United States)

    Maggio, Antonella; Riccobono, Luana; Spadaro, Vivienne; Campisi, Patrizia; Bruno, Maurizio; Senatore, Felice

    2015-05-01

    The chemical composition of the essential oil isolated from the aerial parts of Pulicaria sicula (L.) Moris was characterized by GC-FID and GC/MS analyses. The oil was particularly rich in oxygenated terpenoids. Among the oxygenated monoterpenes (content of 44.5%), the most abundant were borneol (23.7%), bornyl acetate (6.5%), and isothymol isobutyrate (6.2%). Caryophyllene oxide (10.2%), caryophylladienol I (4.3%), and caryophylla-3,8(13)-dien-5β-ol (4.4%) were identified as the main constituents among the oxygenated sesquiterpenes. Furthermore, a complete literature review on the composition of the essential oils of all the Pulicaria taxa studied so far was performed and a principal component analysis (PCA) was carried out.

  19. Characterization of genome-wide SNPs for the water flea Daphnia pulicaria generated by genotyping-by-sequencing (GBS).

    Science.gov (United States)

    Muñoz, Joaquín; Chaturvedi, Anurag; De Meester, Luc; Weider, Lawrence J

    2016-06-27

    The keystone aquatic herbivore Daphnia has been studied for more than 150 years in the context of evolution, ecology and ecotoxicology. Although it is rapidly becoming an emergent model for environmental and population genomics, there have been limited genome-wide level studies in natural populations. We report a unique resource of novel Single Nucleotide Polymorphic (SNP) markers for Daphnia pulicaria using the reduction in genomic complexity with the restriction enzymes approach, genotyping-by-sequencing. Using the genome of D. pulex as a reference, SNPs were scored for 53 clones from five natural populations that varied in lake trophic status. Our analyses resulted in 32,313 highly confident and bi-allelic SNP markers. 1,364 outlier SNPs were mapped on the annotated D. pulex genome, which identified 2,335 genes, including 565 within functional genes. Out of 885 EuKaryotic Orthologous Groups that we found from outlier SNPs, 294 were involved in three metabolic and four regulatory pathways. Bayesian-clustering analyses showed two distinct population clusters representing the possible combined effects of geography and lake trophic status. Our results provide an invaluable tool for future population genomics surveys in Daphnia targeting informative regions related to physiological processes that can be linked to the ecology of this emerging eco-responsive taxon.

  20. Characterization of genome-wide SNPs for the water flea Daphnia pulicaria generated by genotyping-by-sequencing (GBS)

    Science.gov (United States)

    Muñoz, Joaquín; Chaturvedi, Anurag; De Meester, Luc; Weider, Lawrence J.

    2016-01-01

    The keystone aquatic herbivore Daphnia has been studied for more than 150 years in the context of evolution, ecology and ecotoxicology. Although it is rapidly becoming an emergent model for environmental and population genomics, there have been limited genome-wide level studies in natural populations. We report a unique resource of novel Single Nucleotide Polymorphic (SNP) markers for Daphnia pulicaria using the reduction in genomic complexity with the restriction enzymes approach, genotyping-by-sequencing. Using the genome of D. pulex as a reference, SNPs were scored for 53 clones from five natural populations that varied in lake trophic status. Our analyses resulted in 32,313 highly confident and bi-allelic SNP markers. 1,364 outlier SNPs were mapped on the annotated D. pulex genome, which identified 2,335 genes, including 565 within functional genes. Out of 885 EuKaryotic Orthologous Groups that we found from outlier SNPs, 294 were involved in three metabolic and four regulatory pathways. Bayesian-clustering analyses showed two distinct population clusters representing the possible combined effects of geography and lake trophic status. Our results provide an invaluable tool for future population genomics surveys in Daphnia targeting informative regions related to physiological processes that can be linked to the ecology of this emerging eco-responsive taxon. PMID:27346179

  1. Pulicaria jaubertii extract prevents triglyceride deposition in 3T3-L1 adipocytes

    Science.gov (United States)

    Currently, levels of obesity in Middle Eastern countries are increasing. Phytochemicals have anti-obesogenic properties as evidenced by prevention of adipocyte differentiation. In Yemen, Pulicaria jaubertii E.Gamal-Eldin (PJ) is a food additive and a traditional medicine. We tested the ability of ex...

  2. Acute Oral Toxicity Studies of Ethanol Leaf Extracts Of Derris Scandens & Pulicaria Wightiana In Albino Rats

    Directory of Open Access Journals (Sweden)

    Vidya Sabbani

    2015-02-01

    Full Text Available Objective: The present study was designed to find out LD50 and to ascertain the safety of ethanol extracts of leaves of Derris scan dens and Pulicaria wightiana by acute oral toxicity study in female rats as per OECD guideline 425.Methods: Rats were sequentially administered with ethanol leaf extracts of Derris scandens (Ds & Pulicaria wightiana(Pw  in single dosages of 175, 550, and 2000 mg/kg of body weight. All the animals were individually studied for mortality, wellness parameters and body weight for 14 days.Results: No mortality and no significant changes were observed in body weight and wellness parameters at 175, 550 and 2000 mg/kg body wt. doses of both Derris scandens and Pulicaria wightiana , which reveal the safety of these plants  in the doses up to 2000 mg/kg body weight.Conclusion: Conclusively, LD50 value of ethanol extracts of leaves of Derris scandens and Pulicaria wightiana were found to be more than 2000 mg/kg body weight.

  3. Green synthesis of silver nanoparticles mediated by Pulicaria glutinosa extract

    Directory of Open Access Journals (Sweden)

    Khan M

    2013-04-01

    Full Text Available Mujeeb Khan,1 Merajuddin Khan,1 Syed Farooq Adil,1 Muhammad Nawaz Tahir,2 Wolfgang Tremel,2 Hamad Z Alkhathlan,1 Abdulrahman Al-Warthan,1 Mohammed Rafiq H Siddiqui1 1Department of Chemistry, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia; 2Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg-University of Mainz, Mainz, Germany Abstract: The green synthesis of metallic nanoparticles (NPs has attracted tremendous attention in recent years because these protocols are low cost and more environmentally friendly than standard methods of synthesis. In this article, we report a simple and eco-friendly method for the synthesis of silver NPs using an aqueous solution of Pulicaria glutinosa plant extract as a bioreductant. The as-prepared silver NPs were characterized using ultraviolet–visible spectroscopy, powder X-ray diffraction, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier-transform infrared spectroscopy. Moreover, the effects of the concentration of the reductant (plant extract and precursor solution (silver nitrate, the temperature on the morphology, and the kinetics of reaction were investigated. The results indicate that the size of the silver NPs varied as the plant extract concentration increased. The as-synthesized silver NPs were phase pure and well crystalline with a face-centered cubic structure. Further, Fourier-transform infrared spectroscopy analysis confirmed that the plant extract not only acted as a bioreductant but also functionalized the NPs' surfaces to act as a capping ligand to stabilize them in the solvent. The developed eco-friendly method for the synthesis of NPs could prove a better substitute for the physical and chemical methods currently used to prepare metallic NPs commonly used in cosmetics, foods, and medicines. Keywords: surface plasmon resonance, metallic nanoparticles, eco-friendly, capping ligand

  4. Isolation and antimicrobial activity of two phenolic compounds from Pulicaria odora L.

    Science.gov (United States)

    Ezoubeiri, A; Gadhi, C A; Fdil, N; Benharref, A; Jana, M; Vanhaelen, M

    2005-06-01

    The essential oil of Pulicaria odora, a Moroccan medicinal plant; was analyzed by GC-MS, and subjected to column chromatography on silica gel. Two major constituents were isolated and identified as 2-isopropyl-4-methylphenol (1) and isobutyric acid 2-isopropyl-4-methylphenylester (2), by analysis of spectroscopic data (MS, 1H NMR, 13C NMR, DEPT, COSY, HMQC and HMBC experiments). The isolated compounds are reported for the first time from Pulicaria genus. The essential oil and its major constituents (compounds 1 and 2) were examined for antibacterial and antifungal activity in vitro using the diffusion and dilution methods. Results showed that the essential oil and the 2-isopropyl-4-methylphenol (1) exhibited a very significant antibacterial and antifungal activity, while the isobutyric acid 2-isopropyl-4-methylphenylester (2) was inactive for all tested strains.

  5. Chemical composition and antibacterial activity of essential oil of Pulicaria odora L.

    Science.gov (United States)

    Hanbali, Fadwa E L; Akssira, Mohamed; Ezoubeiri, Aicha; Gadhi, Chems Eddoha A; Mellouki, Fouad; Benherraf, Ahmed; Blazquez, Amparo M; Boira, Herminio

    2005-07-14

    The chemical composition of the volatile oil constituent from Pulicaria odora L. roots has been analyzed by GC/MS. Twenty-seven components were identified, being thymol (47.83%) and its derivative isobutyrate (30.05%) the main constituents in the oil. Furthermore, the oil was tested against seven bacteria at different concentrations. Results showed that the oil exhibited a significant antibacterial activity.

  6. Using elemental ratios of calcium and strontium to track calcium availability in the freshwater zooplankton Daphnia pulicaria

    Science.gov (United States)

    Peters, Stephen C.; Lockwood, Ryan; Williamson, Craig E.; Saros, Jasmine E.

    2008-12-01

    The assimilation of elements by an organism is dependent on both the environmental availability of the element and the processes of the organism. For some elements, organisms have a challenging time discriminating between nearly identical chemical analogs, for example, calcium and strontium. We tested the hypothesis that in environments where a desired element is scarce, the organism will assimilate a chemically similar analog at an increased rate. Populations of Daphnia pulicaria were manipulated using a microcosm in situ experiment and the results of that experiment tested with a field survey. Experimental results indicated a correlation between higher environmental calcium concentration and lower [Sr]/[Ca] ratios (R2 = 0.91, p < 0.05), suggesting that Daphnia in high calcium environments will assimilate more calcium relative to strontium. Field survey results across eight lakes confirmed that as lake calcium concentration increased, the value of [Sr]/[Ca] between the organism and the lake water decreased (R2 = 0.60, p < 0.05). Measurement of the elemental ratio of major and trace element analogs within organisms compared to their environments may be a useful tool for measuring the relative bioavailability of the major element, and provide insight into elemental limitation in other calcifying aquatic invertebrates.

  7. Composition and antioxidant activities of Iranian Pulicaria gnaphalodes essential oil in Soybean oil.

    Science.gov (United States)

    Shariatifar, Nabi; Kamkar, Abolfazl; Shamse-Ardekani, Mohammad Reza; Misagi, Ali; Akhonzade, Afshin; Jamshidi, Amir Hossein

    2014-07-01

    The essential oil from aerial parts of Pulicaria gnaphalodes was studied in soybean oil. The aim of this study was to evaluate the antioxidant activitiey of Iranian Pulicaria gnaphalodes essential oil in soybean oil during the storage period. The essential oil obtained from Pulicaria gnaphalodes by hydrodistillation and analyzed by GC/Mass. Fifty-eight compounds representing 90.7% of total was identified. Main ingredient in the oil were involved α -Pinene (30.2%), 1,8-Cineole (12.1%), Beta-Citronellol (9.6%), Mertenol (6.6%), α-Terpineol (6.1%), 4-Terpineol (5.9%) and Chrysanthenone (2.9%). Different concentrations (0.200, 400 and 800 ppm) of essential oil and β hydroxyl toluene (BHT; 100 and 200 ppm) was added to soybean oil and incubated for 35 days at 65°C. Peroxide values (PVs) and thiobarbitoric acid-reactive substances (TBARs) levels were measured every week during the time period of the study. Moreover, antioxidant capacity of the essential oil was determined using 1,1 diphenyl-2- picryl hydrazyl (DPPH) and β-carotene-linoleic acid methods. Values were compared among groups in each incubation time using ANOVA test. Results revealed that DPPH β-carotene-linolic acid assay findings on the P. gnaphalodes essential oil were lower than these of synthetic antioxidant, BHT. Moreover, during the incubation time, P. gnaphalodes essential oil lowered PVs and TBARs levels when compared to the control (pfood flavor, natural antioxidant and a preventive agent for many diseases caused by free radicals. PMID:25015444

  8. Composition and antioxidant activities of Iranian Pulicaria gnaphalodes essential oil in Soybean oil.

    Science.gov (United States)

    Shariatifar, Nabi; Kamkar, Abolfazl; Shamse-Ardekani, Mohammad Reza; Misagi, Ali; Akhonzade, Afshin; Jamshidi, Amir Hossein

    2014-07-01

    The essential oil from aerial parts of Pulicaria gnaphalodes was studied in soybean oil. The aim of this study was to evaluate the antioxidant activitiey of Iranian Pulicaria gnaphalodes essential oil in soybean oil during the storage period. The essential oil obtained from Pulicaria gnaphalodes by hydrodistillation and analyzed by GC/Mass. Fifty-eight compounds representing 90.7% of total was identified. Main ingredient in the oil were involved α -Pinene (30.2%), 1,8-Cineole (12.1%), Beta-Citronellol (9.6%), Mertenol (6.6%), α-Terpineol (6.1%), 4-Terpineol (5.9%) and Chrysanthenone (2.9%). Different concentrations (0.200, 400 and 800 ppm) of essential oil and β hydroxyl toluene (BHT; 100 and 200 ppm) was added to soybean oil and incubated for 35 days at 65°C. Peroxide values (PVs) and thiobarbitoric acid-reactive substances (TBARs) levels were measured every week during the time period of the study. Moreover, antioxidant capacity of the essential oil was determined using 1,1 diphenyl-2- picryl hydrazyl (DPPH) and β-carotene-linoleic acid methods. Values were compared among groups in each incubation time using ANOVA test. Results revealed that DPPH β-carotene-linolic acid assay findings on the P. gnaphalodes essential oil were lower than these of synthetic antioxidant, BHT. Moreover, during the incubation time, P. gnaphalodes essential oil lowered PVs and TBARs levels when compared to the control (p<0.001). According to our results essential oil was less effective than synthetic antioxidant. Therefore it may be used as a food flavor, natural antioxidant and a preventive agent for many diseases caused by free radicals.

  9. Synthesis of silver nanoparticles using methanol and dichloromethane extracts of Pulicaria gnaphalodes (Vent.) Boiss. aerial parts.

    Science.gov (United States)

    Chitsazi, Mohammad Reza; Korbekandi, Hassan; Asghari, Gholamreza; Bahri Najafi, Rahim; Badii, Akbar; Iravani, Siavash

    2016-01-01

    The objectives were to study the potential of Pulicaria gnaphalodes (Vent.) Boiss. aerial parts in production of nanoparticles and the effect of the extraction solvent on the produced nanoparticles. Methanol and dichloromethane extracts were prepared by percolation of the plant powder. Both the extracts of P. gnaphalodes (Vent.) Boiss. successfully produced small and polydispersed nanoparticles with low aggregates in early hours of the biotransformation. Methanol extract produced spherical and many single nanoparticles, whereas dichloromethane produced porous polyhedral and more aggregated nanoparticles. Methanol extract of this plant seems to be quiet useful for industrial scale production of nanoparticles.

  10. Combined and single effects of pesticide carbaryl and toxic Microcystis aeruginosa on the life history of Daphnia pulicaria

    NARCIS (Netherlands)

    Cerbin, S.; Kraak, M.H.S.; De Voogt, P.; Visser, P.M.; Van Donk, E.

    2010-01-01

    The combined influence of a pesticide (carbaryl) and a cyanotoxin (microcystin LR) on the life history of Daphnia pulicaria was investigated. At the beginning of the experiments animals were pulse exposed to carbaryl for 24 h and microcystins were delivered bound in Microcystis’ cells at different,

  11. Combined and single effects of pesticide carbaryl and toxic microcystis aeruginosa on the life history of Daphnia pulicaria

    NARCIS (Netherlands)

    S. Cerbin; M.H.S. Kraak; P. de Voogt; P.M. Visser; E. van Donk

    2010-01-01

    The combined influence of a pesticide (carbaryl) and a cyanotoxin (microcystin LR) on the life history of Daphnia pulicaria was investigated. At the beginning of the experiments animals were pulse exposed to carbaryl for 24 h and microcystins were delivered bound in Microcystis’ cells at different,

  12. Involvement of Daphnia pulicaria Sir2 in regulating stress response and lifespan.

    Science.gov (United States)

    Schumpert, Charles A; Anderson, Craig; Dudycha, Jeffry L; Patel, Rekha C

    2016-02-01

    The ability to appropriately respond to proteotoxic stimuli is a major determinant of longevity and involves induction of various heat shock response (HSR) genes, which are essential to cope with cellular and organismal insults throughout lifespan. The activity of NAD+-dependent deacetylase Sir2, originally discovered in yeast, is known to be essential for effective HSR and longevity. Our previous work on HSR inDaphnia pulicaria indicated a drastic reduction of the HSR in older organisms. In this report we investigate the role of Sir2 in regulating HSR during the lifespan of D. pulicaria. We cloned Daphnia Sir2 open reading frame (ORF) to characterize the enzyme activity and confirmed that the overall function of Sir2 was conserved in Daphnia. The Sir2 mRNA levels increased while the enzyme activity declined with age and considering that Sir2 activity regulates HSR, this explains the previously observed age-dependent decline in HSR. Finally, we tested the effect of Sir2 knockdown throughout adult life by using our new RNA interference (RNAi) method by feeding. Sir2 knockdown severely reduced both the median lifespan as well as significantly increased mortality following heat shock. Our study provides the first characterization and functional study of Daphnia Sir2.

  13. Secondary metabolites from two species of Pulicaria and their cytotoxic activity.

    Science.gov (United States)

    Triana, Jorge; López, Mariana; Pérez, Francisco Javier; León, Francisco; Quintana, José; Estévez, Francisco; Hernández, Juan C; González-Platas, Javier; Brouard, Ignacio; Bermejo, Jaime

    2011-11-01

    Two new compounds, the sesquiterpene (1E,5E)-8β-acetoxy-4α-hydroxy-7βH-germacra-1(10),5-dien-14-oic acid (2), and a nor-sesquiterpene, (5E)-8β-acetoxy-4α-hydroxy-7βH-germacr-5-en-10-one (3), were isolated from Pulicaria canariensis ssp. lanata, along with ten known compounds, including the flavonoid 5,3'-dihydroxy-3,7,4'-trimethoxyflavone (4). From Pulicaria burchardii, we isolated seven known compounds; the physical and spectroscopic data of the triterpenoid 3β-hydroxytaraxaster-20-en-30-al (1) are reported. The structures of compounds 1-3 were determined on the basis of HR-MS, and 1D- and 2D-NMR studies. The structure of 2 was corroborated by X-ray crystal diffraction. Cell viability experiments revealed that the semisynthetic flavonoid 4b was the most cytotoxic compound against human leukemia cells, and the cytotoxicity was caused by induction of apoptosis, as determined by microscopy of nuclear changes.

  14. Pulicaria glutinosa Extract: A Toolbox to Synthesize Highly Reduced Graphene Oxide-Silver Nanocomposites

    Directory of Open Access Journals (Sweden)

    Abdulhadi H. Al-Marri

    2015-01-01

    Full Text Available A green, one-step approach for the preparation of graphene/Ag nanocomposites (PE-HRG-Ag via simultaneous reduction of both graphene oxide (GRO and silver ions using Pulicaria glutinosa plant extract (PE as reducing agent is reported. The plant extract functionalizes the surfaces of highly reduced graphene oxide (HRG which helps in conjugating the Ag NPs to HRG. Increasing amounts of Ag precursor enhanced the density of Ag nanoparticles (NPs on HRG. The preparation of PE-HRG-Ag nanocomposite is monitored by using ultraviolet–visible (UV-Vis spectroscopy, powder X-ray diffraction (XRD, and energy dispersive X-ray (EDX. The as-prepared PE-HRG-Ag nanocomposities display excellent surface-enhanced Raman scattering (SERS activity, and significantly increased the intensities of the Raman signal of graphene.

  15. Pulicaria glutinosa extract: a toolbox to synthesize highly reduced graphene oxide-silver nanocomposites.

    Science.gov (United States)

    Al-Marri, Abdulhadi H; Khan, Mujeeb; Khan, Merajuddin; Adil, Syed F; Al-Warthan, Abdulrahman; Alkhathlan, Hamad Z; Tremel, Wolfgang; Labis, Joselito P; Siddiqui, Mohammed Rafiq H; Tahir, Muhammad N

    2015-01-05

    A green, one-step approach for the preparation of graphene/Ag nanocomposites (PE-HRG-Ag) via simultaneous reduction of both graphene oxide (GRO) and silver ions using Pulicaria glutinosa plant extract (PE) as reducing agent is reported. The plant extract functionalizes the surfaces of highly reduced graphene oxide (HRG) which helps in conjugating the Ag NPs to HRG. Increasing amounts of Ag precursor enhanced the density of Ag nanoparticles (NPs) on HRG. The preparation of PE-HRG-Ag nanocomposite is monitored by using ultraviolet-visible (UV-Vis) spectroscopy, powder X-ray diffraction (XRD), and energy dispersive X-ray (EDX). The as-prepared PE-HRG-Ag nanocomposities display excellent surface-enhanced Raman scattering (SERS) activity, and significantly increased the intensities of the Raman signal of graphene.

  16. Chemical composition, antimicrobial, antiradical and anticholinesterase activity of the essential oil of Pulicaria stephanocarpa from Soqotra.

    Science.gov (United States)

    Ali, Nasser A Awadh; Crouch, Rebecca A; Al-Fatimi, Mohamed A; Arnold, Norbert; Teichert, Axel; Setzer, William N; Wessjohann, Ludger

    2012-01-01

    The chemical composition of the hydrodistilled leaf essential oil from Pulicaria stephanocarpa Balf. Fil was determined by GC-MS analysis, and its antimicrobial, antioxidant and anticholinesterase (AChE) activities were evaluated. Eighty-three compounds were identified representing 97.2% of the total oil. (E)-Caryophyllene 13.4%, (E)-nerolidol 8.5%, caryophyllene oxide 8.5%, alpha-cadinol 8.2% spathulenol 6.8% and tau-cadinol 4.7%, were the main components. Antimicrobial activity of the oil, evaluated using the disc diffusion and broth dilution methods, demonstrated the highest susceptibility on Gram-positive bacteria and Candida albicans. The free radical scavenging ability of the oil was assessed by the DPPH assay to show antiradical activity with IC50 of 330 microg/mL. Moreover, the oil revealed an AChE inhibitory activity of 47% at a concentration of 200 microg/mL using Ellman's method.

  17. Chemical Composition and Antimicrobial Activity of the Essential Oil from Aerial Parts of Algerian Pulicaria mauritanica.

    Science.gov (United States)

    Gherib, Mohammed; Bekhechi, Chahrazed; Bekkara, Fewzia Atik; Bighelli, Ange; Casanova, Joseph; Tomi, Félix

    2016-01-01

    One oil sample isolated from aerial parts of Pulicaria mauritanica Coss. from Western Algeria has been analyzed by GC(RI), GC-MS and ¹³C NMR. In total, 21 components, accounting for 97.0% of the oil, were identified. Then, 36 oil samples coming from plants harvested at two flowering periods in three locations were analyzed by GC(RI) and ¹³C NMR. Although all the oil samples exhibited similar composition, dominated by carvotanacetone (89.2-96.1%), the yield of essential oil varied drastically from sample to sample (0.35-1.44%), depending on the location of harvest. The essential oil displayed moderate antimicrobial effect against bacteria, yeast and filamentous fungi (MIC = 2-4 µL/mL).

  18. Immunostimulatory effects of extract of Pulicaria crispa before and after Schistosoma mansoni infection.

    Science.gov (United States)

    Maghraby, Amany S; Shalaby, Nagwa; Abd-Alla, Howida I; Ahmed, Samia A; Khaled, Hussein M; Bahgat, Mahmoud M

    2010-01-01

    The immunostimulatory effects of methanolic extract from Pulicaria crispa were investigated in mice before and after infection with Schistosoma mansoni. Mice were subjected for daily intra-peritoneal injection by the extract (33 ng/mouse) for 10 successive days followed by infecting every mouse with 100 S. mansoni cercariae. Treatment with the extract induced significant increase (p < 0.05) in sera-IL-2 before and after infection. Upon using soluble worm antigen preparation or cancer bladder homogenates as antigens in ELISA, the detected levels of IgG were significantly (p < 0.05) higher in sera from treated-infected mice than untreated P. crispa infected mice. Using crude Escherichia coli lysate as an antigen in ELISA, it was detected a significant (p < 0.05) increase in IgG levels in sera from the extract-treated mice before and after infection.

  19. Systematic of genera Pulicaria Gaertn. and Platycheteae Boiss. from tribe Inuleae s.str (Asteraceae in Iran

    Directory of Open Access Journals (Sweden)

    Peyman Zarin

    2010-04-01

    Full Text Available The genus Pulicaria Gaertn belongs to the tribe Inuleae (Asteraceae. This genus includes five species in Iran (P. dysenterica, P. vulgaris, P. Arabica, P. gnaphalodes and P. salvifolia. The most diagnostic morphological characteristics were kind of pappus, achene, corolla, phyllaries and form of leafs. In the recent study by Anderberg, focusing on the close relationship between the genus Pulicaria and platychaete, they have been announced synonymous. Platychaete includes five species in Iran (P. glucescens, P. carnosa, P. velutina, P. mucronifolia and P. aucheri. In this study the relationships between them were confirmed and therefore, the Anderberg’s view of convergence of the two genera was attested. Also, species identification key, phenogram and distribution map in Iran were provided and discussed.

  20. Age-dependent susceptibilities of Bulinus truncatus snails to an aqueous extract of Pulicaria crispa (Forssk.) Oliv. (Asteraceae) leaves.

    Science.gov (United States)

    Ali, Elnour A; Bushara, Hamid O; Ali, Faisal S; Hussein, Mansour F

    2009-05-01

    This study was carried out to investigate the potential use of the herb Pulicaria crispa in the biological control of different developmental stages of Bulinus truncatus, a major snail intermediate host of urinary schistosomiasis. Age-dependent susceptibilities of mature adult snails, immature snails, juveniles, and one-day old egg masses to aqueous extracts of Pulicaria crispa leaves collected from Khartoum (Sudan) and Riyadh (Saudi Arabia) was determined and compared. The results show the juvenile snails are the most susceptible, followed in descending order by one-day old egg masses, immature snails, and mature adult snails. The P. crispa sample collected from Riyadh was significantly more potent against B. truncatus than that collected from Khartoum, as indicated by the least (LC50) and (LC90) values for all B. truncatus ages.

  1. Antibacterial properties of silver nanoparticles synthesized using Pulicaria glutinosa plant extract as a green bioreductant

    Directory of Open Access Journals (Sweden)

    Khan M

    2014-07-01

    Full Text Available Mujeeb Khan,1 Shams Tabrez Khan,2 Merajuddin Khan,1 Syed Farooq Adil,1 Javed Musarrat,2 Abdulaziz A Al-Khedhairy,2 Abdulrahman Al-Warthan,1 Mohammed Rafiq H Siddiqui,1 Hamad Z Alkhathlan1 1Department of Chemistry, 2Zoology Department, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia Abstract: The antibacterial properties of nanoparticles (NPs can be significantly enhanced by increasing the wettability or solubility of NPs in aqueous medium. In this study, we investigated the effects of the stabilizing agent on the solubility of silver NPs and its subsequent effect on their antimicrobial activities. Silver NPs were prepared using an aqueous solution of Pulicaria glutinosa plant extract as bioreductant. The solution also acts as a capping ligand. During this study, the antimicrobial activities of silver NPs, as well as the plant extract alone, were tested against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Micrococcus luteus. Silver NPs were prepared with various concentrations of the plant extract to study its effect on antimicrobial activity. Interestingly, various concentrations of P. glutinosa extract did not show any effect on the growth of tested bacteria; however, a significant effect on the antimicrobial property of plant extract capped silver NPs (Ag-NPs-PE was observed. For instance, the half maximal inhibitory concentration values were found to decrease (from 4% to 21% with the increasing concentrations of plant extract used for the synthesis of Ag-NPs-PE. These results clearly indicate that the addition of P. glutinosa extracts enhances the solubility of Ag-NPs-PE and, hence, increases their toxicity against the tested microorganisms. Keywords: antibacterial activity, silver nanoparticles, plant extract, Pulicaria glutinosa

  2. Chemical composition of the essential oil from Pulicaria vulgaris var. graeca (Sch.-Bip.) Fiori (Asteraceae) growing wild in Sicily and its antimicrobial activity.

    Science.gov (United States)

    Casiglia, Simona; Riccobono, Luana; Bruno, Maurizio; Senatore, Federica; Senatore, Felice

    2016-01-01

    In this study the chemical composition of the essential oil from aerial parts of Pulicaria vulgaris var. graeca (Sch.-Bip.) Fiori collected in Sicily was evaluated by GC and GC-MS. The main components of P. vulgaris var. graeca oil were hexadecanoic acid (21.7%), β-caryophyllene (14.3%) and geranyl propionate (8.2%). The comparison with other studied oils of genus Pulicaria is discussed. Antibacterial activity against several bacteria, including some ones infesting historical art craft, was also determined.

  3. Chemical composition and biological activity of Pulicaria vulgaris essential oil from Iran.

    Science.gov (United States)

    Sharifi-Rad, Javad; Miri, Abdolhossein; Hoseini-Alfatemi, Seyedeh Mahsan; Sharifi-Rad, Majid; Setzer, William N; Hadjiakhoondi, Abbas

    2014-11-01

    The present study investigated the chemical composition of the essential oil (EO) from aerial parts (flowering stage) of Pulicaria vulgaris Gaertn. by GC-MS. Also, the antimicrobial activity of the EO against Gram-positive bacteria (Bacillus cereus and Staphylococcus aureus), Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and fungi (Aspergillus niger and Candida albicans) was tested. In total, 23 compounds were recognized, accounting for 98.08% of the EO. The main compounds in the EO were thymol (50.22%), p-menth-6-en-2-one (carvotanacetone, 20.2%), thymol isobutyrate (16.88%), menthan-2-one (4.31%), 1-methyl-1,2-propanedione (4.13%), 2,5-dimethoxy-p-cymene (4.01%), myrtenol (1.22%), linalool (1.1%), and β-myrcene (1.9%). Results of antibacterial test of P. vulgaris essential oil showed that all assayed concentrations significantly inhibited the growth of B. cereus, S. aureus, E. coli, and P. aeruginosa at P < 0.05. MIC for B. cereus, S. aureus, E. coli, P. aeruginosa was 17.5, 25.2, 19.4 and 33.2 μg/mL respectively; antifungal screening of the essential oil of P. vulgaris showed that the oil significantly inhibited the growth of A. niger and C. albicans (MIC = 15.5 and 9.9 μg/mL, respectively). Results of cytotoxicity assay showed that the essential oil exhibited a significant cytotoxic activity against both cell lines. In case of MCF-7 and Hep-G2 cell lines, IC50 of the essential oil were 5.36 and 7.16 μg/ml, respectively. The potent antimicrobial and cytotoxic activities of the EO may be attributed to its high contents of thymol, carvotanacetone and thymol isobutyrate. Antimicrobial and antitumor chemotherapies are showing diminishing effectiveness because of emergence of drug-resistance. Hence, using efficient natural chemotherapeutic agents such as Pulicaria vulgaris essential oil with fewer side effects is an encouraging approach to fight cancer and infectious diseases in medicine, agriculture, food science and related fields.

  4. Chemical composition and biological activity of essential oil from Pulicaria undulata from Yemen.

    Science.gov (United States)

    Ali, Nasser A Awadh; Sharopov, Farukh S; Alhaj, Mehdi; Hill, Gabrielle M; Porzel, Andrea; Arnold, Norbert; Setzer, William N; Schmidt, Jürgen; Wessjohann, Ludger

    2012-02-01

    The chemical composition of the essential oil obtained from the leaves of Pulicaria undulata Gamal Ed Din (syn P. orientalis sensu Schwartz and P. jaubertii Gamal Ed Din) was analyzed by GC-MS. Major compounds of P. undulata oil were the oxygenated monoterpenenes, carvotanacetone (91.4%) and 2,5-dimethoxy-p-cymene (2.6.%). The antimicrobial activity of the essential oil was evaluated against six microorganisms, Escherichia coli Pseudomonas aeruginosa, Staphylococcus aureus, methicillin-resistant S. aureus, Bacillus subtilis, and Candida albicans, using disc diffusion and broth microdilution methods. The oil showed the strongest bactericidal activity against Staphylococcus aureus and methicillin-resistant S. aureus, as well as Candida albicans. The essential oil showed moderate cytotoxic activity against MCF-7 breast tumor cells, with an IC50 of 64.6 +/- 13.7 microg/mL. Bioautographic assays were used to evaluate the acetylcholinesterase inhibitory effect as well as antifungal activity of the oil against Cladosporium cucumerinum. PMID:22474974

  5. Protective and Antioxidant Effects of a Chalconoid from Pulicaria incisa on Brain Astrocytes

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    Anat Elmann

    2013-01-01

    Full Text Available Oxidative stress is involved in the pathogenesis of neurodegenerative diseases such as Parkinson's and Alzheimer's diseases. Astrocytes, the most abundant glial cells in the brain, protect neurons from reactive oxygen species (ROS and provide them with trophic support, such as glial-derived neurotrophic factor (GDNF. Thus, any damage to astrocytes will affect neuronal survival. In the present study, by activity-guided fractionation, we have purified from the desert plant Pulicaria incisa two protective compounds and determined their structures by spectroscopic methods. The compounds were found to be new chalcones—pulichalconoid B and pulichalconoid C. This is the first study to characterize the antioxidant and protective effects of these compounds in any biological system. Using primary cultures of astrocytes, we have found that pulichalconoid B attenuated the accumulation of ROS following treatment of these cells with hydrogen peroxide by 89% and prevented 89% of the H2O2-induced death of astrocytes. Pulichalconoid B exhibited an antioxidant effect both in vitro and in the cellular antioxidant assay in astrocytes and microglial cells. Pulichalconoid B also caused a fourfold increase in GDNF transcription in these cells. Thus, this chalcone deserves further studies in order to evaluate if beneficial therapeutic effect exists.

  6. Chemical composition and biological activity of essential oil from Pulicaria undulata from Yemen.

    Science.gov (United States)

    Ali, Nasser A Awadh; Sharopov, Farukh S; Alhaj, Mehdi; Hill, Gabrielle M; Porzel, Andrea; Arnold, Norbert; Setzer, William N; Schmidt, Jürgen; Wessjohann, Ludger

    2012-02-01

    The chemical composition of the essential oil obtained from the leaves of Pulicaria undulata Gamal Ed Din (syn P. orientalis sensu Schwartz and P. jaubertii Gamal Ed Din) was analyzed by GC-MS. Major compounds of P. undulata oil were the oxygenated monoterpenenes, carvotanacetone (91.4%) and 2,5-dimethoxy-p-cymene (2.6.%). The antimicrobial activity of the essential oil was evaluated against six microorganisms, Escherichia coli Pseudomonas aeruginosa, Staphylococcus aureus, methicillin-resistant S. aureus, Bacillus subtilis, and Candida albicans, using disc diffusion and broth microdilution methods. The oil showed the strongest bactericidal activity against Staphylococcus aureus and methicillin-resistant S. aureus, as well as Candida albicans. The essential oil showed moderate cytotoxic activity against MCF-7 breast tumor cells, with an IC50 of 64.6 +/- 13.7 microg/mL. Bioautographic assays were used to evaluate the acetylcholinesterase inhibitory effect as well as antifungal activity of the oil against Cladosporium cucumerinum.

  7. Protective and antioxidant effects of a chalconoid from Pulicaria incisa on brain astrocytes.

    Science.gov (United States)

    Elmann, Anat; Telerman, Alona; Erlank, Hilla; Mordechay, Sharon; Rindner, Miriam; Ofir, Rivka; Kashman, Yoel

    2013-01-01

    Oxidative stress is involved in the pathogenesis of neurodegenerative diseases such as Parkinson's and Alzheimer's diseases. Astrocytes, the most abundant glial cells in the brain, protect neurons from reactive oxygen species (ROS) and provide them with trophic support, such as glial-derived neurotrophic factor (GDNF). Thus, any damage to astrocytes will affect neuronal survival. In the present study, by activity-guided fractionation, we have purified from the desert plant Pulicaria incisa two protective compounds and determined their structures by spectroscopic methods. The compounds were found to be new chalcones-pulichalconoid B and pulichalconoid C. This is the first study to characterize the antioxidant and protective effects of these compounds in any biological system. Using primary cultures of astrocytes, we have found that pulichalconoid B attenuated the accumulation of ROS following treatment of these cells with hydrogen peroxide by 89% and prevented 89% of the H2O2-induced death of astrocytes. Pulichalconoid B exhibited an antioxidant effect both in vitro and in the cellular antioxidant assay in astrocytes and microglial cells. Pulichalconoid B also caused a fourfold increase in GDNF transcription in these cells. Thus, this chalcone deserves further studies in order to evaluate if beneficial therapeutic effect exists.

  8. Chaperone potential of Pulicaria undulata extract in preventing aggregation of stressed proteins.

    Science.gov (United States)

    Ghahghaei, Arezou; Valizadeh, Jafar; Nazari, Shahrzad; Ravandeh, Mehdi

    2014-06-01

    This study examined the effect of an aqueous extract of Pulicaria undulata on the 1,4-dithiothreitol (DTT)-induced aggregation of proteins. The effects of the chaperone properties of P. undulata extract on protein aggregation were determined by measuring light scattering absorption, fluorescence, and circular dichroism (CD) spectroscopy. The aqueous extract of P. undulata possesses good chaperone properties but the protection effect was varied in different protein. The extract showed a higher level of protection in high molecular weight proteins than in those of low molecular weight. Using a fluorescence study, the present study provides information on the hydrophobic area of proteins interacting with the P. undulata extract. In fact, by increasing the concentration of the P. undulata extract, the hydrophic area of the protein decreased. CD spectroscopy also revealed that DTT caused changes in both the tertiary and the secondary structure of the proteins, while in the presence of P. undulata extract, there was little change. Our finding suggests the possibility of using P. undulata extract for the inhibition of aggregation and the deposition of protein in disease.

  9. Antibacterial properties of silver nanoparticles synthesized using Pulicaria glutinosa plant extract as a green bioreductant.

    Science.gov (United States)

    Khan, Mujeeb; Khan, Shams Tabrez; Khan, Merajuddin; Adil, Syed Farooq; Musarrat, Javed; Al-Khedhairy, Abdulaziz A; Al-Warthan, Abdulrahman; Siddiqui, Mohammed Rafiq H; Alkhathlan, Hamad Z

    2014-01-01

    The antibacterial properties of nanoparticles (NPs) can be significantly enhanced by increasing the wettability or solubility of NPs in aqueous medium. In this study, we investigated the effects of the stabilizing agent on the solubility of silver NPs and its subsequent effect on their antimicrobial activities. Silver NPs were prepared using an aqueous solution of Pulicaria glutinosa plant extract as bioreductant. The solution also acts as a capping ligand. During this study, the antimicrobial activities of silver NPs, as well as the plant extract alone, were tested against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Micrococcus luteus. Silver NPs were prepared with various concentrations of the plant extract to study its effect on antimicrobial activity. Interestingly, various concentrations of P. glutinosa extract did not show any effect on the growth of tested bacteria; however, a significant effect on the antimicrobial property of plant extract capped silver NPs (Ag-NPs-PE) was observed. For instance, the half maximal inhibitory concentration values were found to decrease (from 4% to 21%) with the increasing concentrations of plant extract used for the synthesis of Ag-NPs-PE. These results clearly indicate that the addition of P. glutinosa extracts enhances the solubility of Ag-NPs-PE and, hence, increases their toxicity against the tested microorganisms.

  10. Toxic effect of selenium on the zooplankton, Daphnia magna and Daphnia pulicaria, in water and the food source (Chlamydomonas reinhardtii)

    Energy Technology Data Exchange (ETDEWEB)

    Boyum, K.W.

    1984-01-01

    Acute and chronic toxicity experiments were performed on the zooplankton, Daphnia magna and Daphnia pulicaria, to investigate the toxicity of selenium on these aquatic invertebrates. The acute 48 h LC/sub 50/ of sodium selenate for Daphnia magna and Daphnia pulicaria were 1.01 and 0.25 mg Se/1, respectively. The 48 h LC/sub 50/ of sodium selenite for D. magna and D. pulicaria were 0.45 and 0.006 mg Se/1, respectively. Chronic 28-day toxicity tests were performed on D. magna at 0.05, 0.10, 0.50, and 1.00 mg Se/1 as sodium selenate in the water and with two food types. One food type was algae raised in clean Lake Michigan water and the second treatment was algae raised in media with selenium concentrations corresponding to those in the water cited above. When compared to Daphnia fed selenium-free algae, D. magna fed selenium-laden algae had greater survival, a greater number of offspring produced, and a greater intrinsic growth rate, r, at the toxicant concentration in the water of 0.05, 0.10, and 0.50 mg Se/1. These parameters were, however, lower than those observed in the controls. Uptake of /sup 75/Se as sodium selenate in D. magna was reduced in the presence of selenium-laden algae and DL-selenomethionine, while L-methionine increased the uptake of /sup 75/Se. Selenium bound to an amino acid such as Dl-selenomethionine or organically bound within an algal food source appears to be preferentially incorporated thereby reducing the uptake of inorganic forms from the water.

  11. Toxic effect of selenium on the zooplankton, Daphnia magna and Daphnia pulicaria, in water and the food source (Chlamydomonas reinhardtii)

    International Nuclear Information System (INIS)

    Acute and chronic toxicity experiments were performed on the zooplankton, Daphnia magna and Daphnia pulicaria, to investigate the toxicity of selenium on these aquatic invertebrates. The acute 48 h LC50 of sodium selenate for Daphnia magna and Daphnia pulicaria were 1.01 and 0.25 mg Se/1, respectively. The 48 h LC50 of sodium selenite for D. magna and D. pulicaria were 0.45 and 0.006 mg Se/1, respectively. Chronic 28-day toxicity tests were performed on D. magna at 0.05, 0.10, 0.50, and 1.00 mg Se/1 as sodium selenate in the water and with two food types. One food type was algae raised in clean Lake Michigan water and the second treatment was algae raised in media with selenium concentrations corresponding to those in the water cited above. When compared to Daphnia fed selenium-free algae, D. magna fed selenium-laden algae had greater survival, a greater number of offspring produced, and a greater intrinsic growth rate, r, at the toxicant concentration in the water of 0.05, 0.10, and 0.50 mg Se/1. These parameters were, however, lower than those observed in the controls. Uptake of 75Se as sodium selenate in D. magna was reduced in the presence of selenium-laden algae and DL-selenomethionine, while L-methionine increased the uptake of 75Se. Selenium bound to an amino acid such as Dl-selenomethionine or organically bound within an algal food source appears to be preferentially incorporated thereby reducing the uptake of inorganic forms from the water

  12. Pulicaria jaubertii E. Gamal-Eldin reduces triacylglyceride content and modifies cellular antioxidant pathways in 3T3-L1 adipocytes

    Science.gov (United States)

    Currently, levels of obesity in Middle Eastern countries are increasing. Phytochemicals have anti-obesogenic properties as evidenced by prevention of adipocyte differentiation. In Yemen, Pulicaria jaubertii E.Gamal-Eldin (PJ) is a food additive and a traditional medicine. We evaluated the ability of...

  13. Chemical composition and biological evaluation of essential oils of Pulicaria jaubertii

    Directory of Open Access Journals (Sweden)

    Ghada A Fawzy

    2013-01-01

    Full Text Available Background: The present study reports and compares the results of Gas Chromatographic-Mass analyses of Pulicaria jaubertii leaf (P-1 and root (P-2 essential oils, as well as their in vitro antimicrobial and cytotoxic activities. Materials and Methods: The chemical composition of P-1 and P-2 essential oils of P. jaubertii, was investigated by GC-MS. Moreover, the essential oils were evaluated for their antimicrobial activity using the broth micro-dilution assay for minimum inhibitory concentrations (MIC. The crystal violet staining method (CVS was used for evaluation of their cytotoxic activity on HEPG-2 and MCF-7 human cell lines. Results: This investigation led to the identification of 16 constituents in P-1 , and 23 constituents in P-2 , representing 99.92% and 94.74% of the oils respectively. Oxygenated monoterpenes were found to be the major group in both P-1 (99.47% and P-2 (89.88%. P-1 consists almost entirely of p-Menth-6-en-2-one (Carvotanacetone, 98.59%. P-2 is characterized by high contents of each of Dimethoxydurene (38.48%, Durenol (26.89% and 2′,4Ͳ-Dimethoxy-3′-methylacetophenone (20.52%. Both oils showed moderate antimicrobial activity against the Gram-positive strains and C. albicans. However, no activity was shown against Gram-negative bacteria. P-1 showed a significant cytotoxic activity against both MCF-7 and HEPG-2 (IC 50 = 3.8 and 5.1 μg/ml, respectively, while P-2 showed selective cytotoxic activity against MCF-7 cell line (IC 50 = 9.3 μg/ml. Conclusion: The potent cytotoxic and moderate antimicrobial activities of P-1 may be attributed to its high content of Carvotanacetone.

  14. Mating behaviours of Daphnia pulicaria, a cyclic parthenogen: comparisons with copepods

    Science.gov (United States)

    Brewer, M. C.

    1998-01-01

    The pre-and post-contact mating behaviours of Daphnia pulicaria are investigated by direct observations of vertical distributions, swimming behaviours and male-female interactions. Analysis of vertical distributions in a 1 m deep, thermally stratified migration chamber reveals that females were always located in the upper layer of the water column but males exhibited a bimodal depth distribution, in which an individual's depth was a function of body length and water temperature. The observed distributions of males may be the result of several interacting pressures; predation avoidance, life-history optimization, and avoidance of assortative mating. Male swimming behaviour was faster and orthogonal to that of females, which is in agreement with the predictions of encounter-rate maximization models. Video recordings of males and females interacting in a 1-litre vessel showed that males both pursued and contacted other males more often than females. Thus, there was no evidence that Daphnia are able to use water-borne chemical signals to locate and identify potential mates. However, the average duration of male-female contacts (13.8 s) was much longer than those between males (1.6 s), suggesting that males can determine the sex of contacted individuals.Daphnia mating behaviour is significantly more complex than previously acknowledged. In contrast to the conventional view of Daphnia males swimming more-or-less randomly and mating with any individual encountered, they exhibit behaviours which increase the potential of mating with females while reducing the risk of predation. Several male behaviours, such as 'scanning' and the performance of area-restricted spirals upon encounter, are similar to those reported for some copepods and may be common to zooplankton that lack sophisticated chemosensory abilities. The possibility that Daphnia may also be able to assess such important female attributes as species and reproductive status is discussed.

  15. Experimental assessment of environmental influences on the stable isotopic composition of Daphnia pulicaria and their ephippia

    Science.gov (United States)

    Schilder, J.; Tellenbach, C.; Möst, M.; Spaak, P.; van Hardenbroek, M.; Wooller, M. J.; Heiri, O.

    2015-02-01

    The stable isotopic composition of fossil resting eggs (ephippia) of Daphnia spp. is being used to reconstruct past environmental conditions in lake ecosystems. However, the underlying assumption that the stable isotopic composition of the ephippia reflects the stable isotopic composition of the parent Daphnia, of their diet and of the environmental water have yet to be confirmed in a controlled experimental setting. We performed experiments with Daphnia pulicaria cultures, which included a control treatment conducted at 12 °C in filtered lake water and with a diet of fresh algae, and three treatments in which we manipulated the stable carbon isotopic composition (δ13C value) of the algae, stable oxygen isotopic composition (δ18O value) of the water, and the water temperature, respectively. The stable nitrogen isotopic composition (δ15N value) of the algae was similar for all treatments. At 12 °C, differences in algal δ13C values and in δ18O values of water are reflected in those of Daphnia. The differences between ephippia and Daphnia stable isotope ratios were similar in the different treatments (δ13C: + 0.2 ± 0.4‰ (SD); δ15N: -1.6 ± 0.4‰; δ18O: -0.9 ± 0.4‰) indicating that changes in dietary δ13C and δ18O values of water are passed on to these fossilizing structures. A higher water temperature (20 °C) resulted in lower δ13C values in Daphnia and ephippia than in the other treatments with the same food source and in a minor change in the difference between δ13C values of ephippia and Daphnia (to -1.3 ± 0.3‰). This may have been due to microbial processes or increased algal respiration rates in the experimental containers, which may not affect Daphnia in natural environments. There was no significant difference in the offset between δ18O and δ15N values of ephippia and Daphnia between the 12 °C and 20 °C treatments, but the δ18O values of Daphnia and ephippia were on average 1.2‰ lower at 20 °C compared with 12 °C. We conclude

  16. Characterization of a Pantoea stewartii TTSS gene required for persistence in its flea beetle vector

    Science.gov (United States)

    Stewart's bacterial wilt of maize is caused by Pantoea stewartii subsp. stewartii (Pnss), a bacterium that is transmitted by the flea beetle, Chaetocnema pulicaria. Few studies have focused on the molecular basis of the interactions of Pnss with its vector. Genome analyses indicated that Pnss carri...

  17. Chronic effects of 2,2'-dichlorobiphenyl on reproduction, mortality, growth, and respiration of daphnia pulicaria

    Energy Technology Data Exchange (ETDEWEB)

    Bridgham, S.D.

    1988-01-01

    Previous studies have shown toxic effects of polychlorinated biphenyls (PCBs) on aquatic life only in the micro g/L range, well above normal ambient concentrations. Daphnia pulicaria was isolated from Lake Erie and exposed to 50 ng/L to 10 micro g/L of 2,2'-dichlorobiphenyl (DCB) in lifetable and physiological studies. Reproduction, mortality, growth, and respiration were measured for periods up to the entire lifespan of the animal with and without the use of an organic surfactant. Significant mortality and inhibition of reproduction were found at levels as low as 50-100 ng/L in lifetable studies, and no safe level could be determined. A unique, yet repeatable, dose-response curve occurred in lifetables with maximum inhibition at low to intermediate concentrations. Inhibition at the highest level tested, 10 micro g/L, occurred only after continuous exposure for three generations. Increasing concentrations of CBD stimulated growth, while respiration experiments yielded variable results.

  18. A new monoterpene glucoside and complete assignments of dihydroflavonols of Pulicaria jaubertii: potential cytotoxic and blood pressure lowering activity.

    Science.gov (United States)

    Ragab, Ehab A; Raafat, Mohamed

    2016-06-01

    One new monoterpene glucoside and five dihydroflavonols were isolated for the first time from the aerial parts of Pulicaria jaubertii and identified as p-menthane-2-O-β-D-glucopyranoside [1], dihydroquercetin (taxifolin) [2], 7,3'-di-O-methyltaxifolin [3], 3'-O-methyltaxifolin [4], 7-O-methyltaxifolin (padmatin) [5] and 7-O-methyl-dihydrokampferol (7-O-methylaromadenderin) [6]. The structures of these compounds were unambiguously assigned on the basis of NMR spectroscopic data ((1)H, (13)C, DEPT, HSQC, HMBC) and MS analysis. 2D-NMR methods required revision of assignments of H-6 and H-8 for dihydroflavonol compounds. Possible cytotoxic activity as well as blood pressure (BP) lowering activity were tested. The alcoholic extract showed cytotoxic activity against prostate carcinoma (PC-3), breast carcinoma (MCF-7) and hepatocellular carcinoma (HepG-2) human cell lines with IC50 19.1, 20.0 and 24.1 μg, respectively. The higher dose levels of the alcoholic extract significantly reduced normal BP of rats in a dose-dependent manner.

  19. Biogenic synthesis of palladium nanoparticles using Pulicaria glutinosa extract and their catalytic activity towards the Suzuki coupling reaction.

    Science.gov (United States)

    Khan, Mujeeb; Khan, Merajuddin; Kuniyil, Mufsir; Adil, Syed Farooq; Al-Warthan, Abdulrahman; Alkhathlan, Hamad Z; Tremel, Wolfgang; Tahir, Muhammad Nawaz; Siddiqui, Mohammed Rafiq H

    2014-06-28

    Green synthesis of nanomaterials finds the edge over chemical methods due to its environmental compatibility. Herein, we report a facile and eco-friendly method for the synthesis of palladium (Pd) nanoparticles (NPs) using an aqueous solution of Pulicaria glutinosa, a plant widely found in a large region of Saudi Arabia, as a bioreductant. The as-prepared Pd NPs were characterized using ultraviolet-visible (UV-vis) spectroscopy, powder X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), and Fourier transform-infrared spectroscopy (FT-IR). The hydroxyl groups of the plant extract (PE) molecules were found mainly responsible for the reduction and growth of Pd NPs. FT-IR analysis confirmed the dual role of the PE, both as a bioreductant as well as a capping ligand, which stabilizes the surface of Pd NPs. The crystalline nature of the Pd NPs was identified using XRD analysis which confirmed the formation of a face-centered cubic structure (JCPDS: 87-0641, space group: Fm3m (225)). Furthermore, the as-synthesized Pd NPs demonstrated excellent catalytic activity towards the Suzuki coupling reaction under aqueous and aerobic conditions. Kinetic studies of the catalytic reaction monitored using GC confirmed that the reaction completes in less than 5 minutes.

  20. Laboratory evaluation of the toxicity of Perfluorooctane Sulfonate (PFOS) on Selenastrum capricornutum, Chlorella vulgaris, Lemna gibba, Daphnia magna, and Daphnia pulicaria.

    Science.gov (United States)

    Boudreau, T M; Sibley, P K; Mabury, S A; Muir, D G C; Solomon, K R

    2003-04-01

    Perfluorooctane sulfonate (PFOS) is an anthropogenic compound found in trace amounts in many environmental compartments far from areas of production. This, along with the highly persistent nature of PFOS, presents a concern for possible effects in aquatic ecosystems. The objective of this study was to determine the toxicity of PFOS in representative freshwater organisms. Toxicity testing using standard laboratory protocols was performed on the green algae Selenastrum capricornutum and Chlorella vulgaris, the floating macrophyte Lemna gibba, and the invertebrates Daphnia magna and Daphnia pulicaria. No observable effect concentration (NOEC) values were generated from the most sensitive endpoints for all organisms. Autotroph inhibition of growth NOEC values were 5.3, 8.2, and 6.6 mg/L for S. capricornutum, C. vulgaris, and L. gibba, respectively. The 48-h immobility NOEC values for D. magna and D. pulicaria were 0.8 and 13.6 mg/L, respectively. In comparison to immobility, the 21-day lethality NOEC for D. magna was 5.3 mg/L. Based on effect (immobility) values, the most sensitive of all test organisms was D. magna. The most sensitive organism based on 50% inhibition of growth (IC(50)) was L. gibba, with an IC(50) value of 31.1 mg/L determined from wet weight. This is 4.3 times less than the LC(50) for D. pulicaria, which was 134 mg/L. Significant adverse effects (p 134 mg/L. The results indicate that under laboratory conditions PFOS is acutely toxic to freshwater organisms at concentrations at or near 100 mg/L. Based on known environmental concentrations of PFOS, which occur in the low ng/L to low microg/L range, there is no apparent risk to freshwater systems. However, further work is required to investigate long-term effects in these and other freshwater organisms.

  1. Effect of nutrient availability on the uptake of PCB congener 2,2',6,6'-tetrachlorobiphenyl by a diatom (Stephanodiscus minutulus) and transfer to a zooplankton (Daphnia pulicaria).

    Science.gov (United States)

    Lynn, Scott G; Price, David J; Birge, Wesley J; Kilham, Susan S

    2007-06-01

    The objective of this study was to examine the importance of nutrient status of a diatom (Stephanodiscus minutulus) to the uptake of PCB congener #54 (2,2',6,6'-tetrachlorobiphenyl) and the subsequent transfer of PCB to a pelagic grazing zooplankton (Daphnia pulicaria). The algae, which were grown under different nutrient treatments, were then fed to a zooplankton to examine the subsequent food chain transfer of PCB. Algal cultures were grown for at least 2 weeks in a steady state condition in (1) non-limiting, (2) low-Si, (3) low-N or (4) low-P media. Steady state algal cultures were dosed with 0.2 microg L(-1) PCB and were sampled for PCB uptake after 24h. D. pulicaria were allowed to graze on these same cultures for 48 h before being analyzed for PCB body burdens. Low-Si (68% or 0.135 microg L(-1) of PCB) and low-P cultures (62%) had significantly higher percentage uptake of total PCB than the non-limiting (55%) or low-N (52%) treatments. When these values were divided by biochemical or elemental parameters, PCB per lipids (microg microg(-1)) had one of the lowest coefficients of variation (CV) across the four treatments, indicating their importance in PCB uptake. When equal biovolumes of the four different treatment cultures were fed to zooplankton, both the low-N (13.9 ng PCB mg wet weight(-1)) and the low-P (9.6 ng PCB mg wet weight(-1)) grazing D. pulicaria had significantly higher PCB per wet weight than the low-Si (5.6 ng PCB mg wet weight(-1)) and non-limited (2.6 ng PCB mg wet weight(-1)) grazing D. pulicaria. There were no significant differences between algal nutrient treatments in PCB per wet weight of zooplankton grazing on clean algal food in PCB contaminated media. This study indicates that uptake of PCB by phytoplankton can be significantly altered by nutrient availability which subsequently affects transfer to zooplankton, potentially through such responses as grazing rate and lipid assimilation.

  2. Populism

    OpenAIRE

    Abts, Koenraad; van Kessel, Stijn

    2015-01-01

    Populism is a concept applied to a wide range of political movements and actors across the globe. There is, at the same time, considerable confusion about the attributes and manifestation of populism, as well as its impact on democracy. This contribution identifies the defining elements of the populist ideology and discusses the varieties in which populism manifests itself, for instance as a component of certain party families. We finally discuss various normative interpretations of populism,...

  3. Evaluation of the effect of Pulicaria gnaphalodes and Perovskia abrotanoides essential oil extracts against Mycobacterium tuberculosis strains

    Directory of Open Access Journals (Sweden)

    Fereshte Hozoorbakhsh

    2016-01-01

    Full Text Available Background: Mycobacterium tuberculosis (MTB is the causative agent of tuberculosis (TB, which remains one of the major public health problems in the world. The increasing incidence of multidrug-resistant tuberculosis (MDR-TB and extensively drug-resistant tuberculosis (XDR-TB worldwide highlights the urgent need to search for alternative antimycobacterial agents. More and more people in developing countries utilize traditional medicine for their major primary health care needs. It has been determined that the medicinal plants Pulicaria gnaphalodes and Perovskia abrotanoides possess strong antibacterial effect. Materials and Methods: In this study, the antimycobacterial effects of P. gnaphalodes and P. abrotanoides essential oil on MTB were examined. Essential oil was prepared from P. gnaphalodes aerial parts and P. abrotanoides flower. The effects of six different concentrations (20 μg/ml, 40 μg/ml, 80 μg/ml, 160 μg/ml, 320 μg/ml, and 640 μg/ml were examined against sensitive isolates of MTB and MTB H37Rv (ATCC 27294. Results: The results showed that P. gnaphalodes and P. abrotanoides essential oil extracts have strong inhibitory effects on MTB. This activity for P. gnaphalodes was observed from very low (4% to good (70.9% effect; meanwhile, this activity for P. abrotanoides was observed from very low (4% to strong (86% effect. Conclusion: The mean of inhibition percentage for P. gnaphalodes and P. abrotanoides in 640 μg/ml was 58.1% and 76.2%, respectively. So, P. abrotanoides plant is more effective against MTB than P. gnaphalodes. Identification of the effective fraction against MTB is a further step to be studied.

  4. Sesquiterpenes from an Egyptian herbal medicine, Pulicaria undulate, with inhibitory effects on nitric oxide production in RAW264.7 macrophage cells.

    Science.gov (United States)

    Hegazy, Mohamed-Elamir F; Matsuda, Hisashi; Nakamura, Seikou; Yabe, Mikuko; Matsumoto, Tomoko; Yoshikawa, Masayuki

    2012-01-01

    The methylene chloride-methanol (1 : 1) extract from the air-dried aerial parts of wild Pulicaria undulata collected in North Sinia, Egypt, showed inhibitory effects on lipopolysaccharide (LPS)-induced production of nitric oxide (NO) in RAW264.7 macrophages. From the extract, three new sesquiterpenes named 5α-hydroperoxyivalin, 8-epi-xanthanol, and 8-epi-isoxanthanol were isolated together with four known sesquiterpenes. The structure of each new sesquiterpenes was determined on the basis of physicochemical and chemical evidence. In addition, all the sesquiterpenoids significantly inhibited the production of NO. Ivalin (IC50=2.0 μM) and 2α-hydroxyalantolactone (1.8 μM) showed particularly strong inhibitory effects, but had strong cytotoxic effects as well. Furthermore, ivalin and 2α-hydroxyalantolactone concentration-dependently reduced inducible NO synthase (iNOS) protein levels in RAW264.7 cells.

  5. Anti-inflammatory effects of the chloroform extract of Pulicaria guestii ameliorated the neutrophil infiltration and nitric oxide generation in rats.

    Science.gov (United States)

    Alghaithy, A A; El-Beshbishy, H A; Abdel-Naim, A B; Nagy, A A; Abdel-Sattar, E M

    2011-11-01

    Pulicaria guestii Rech.f. & Rawi is a fragrant, perennial herb, which grows wild, west of Al-Madinah, Saudi Arabia. Several reports were published on the anti-inflammatory activity of the sesquiterpene lactones, phenolics and flavonoids, which constitute the main active constituents of the members of the genus Pulicaria. The present study was designed to explore the potential anti-inflammatory effect of P. guestii in several experimental models. The methanol extract of the dried aerial parts of P. guestii was extracted with petroleum ether, chloroform and n-butanol. The chloroform extract was analysed on TLC and examined under UV and visible light in presence of AlCl(3) spray. The free radical scavenging activity and the total phenolic content in the CHCl(3) extract were estimated. The crude methanol extract and the CHCl(3) fraction were examined against carrageenin-induced paw edema and ear edema induced by croton oil application. The crude methanolic extract significantly reduced carrageenin-induced rat paw edema. After fractionation, the chloroform fraction caused significant reduction in carrageenin-induced rat paw edema in addition to diminishing prostaglandin E(2) (PGE(2)) in the inflammatory exudates. Topical application of chloroform fraction significantly reduced rat ear edema induced by croton oil application. In the same model, chloroform fraction reduced neutrophil infiltration, as indicated by the significant decrease in myeloperoxidase activity, and ameliorated histopathological changes induced by croton oil application. In lipopolysaccharide-induced inflammation in rat air pouch, chloroform fraction significantly reduced the nitric oxide level and tumor necrosis factor-α release. In conclusion, the chloroform fraction of P. guestii extract possesses anti-inflammatory activity in several experimental models. Further investigations are needed to identify the active constituents responsible for this anti-inflammatory activity.

  6. Population genetic dynamics of an invasion reconstructed from the sediment egg bank.

    Science.gov (United States)

    Möst, Markus; Oexle, Sarah; Marková, Silvia; Aidukaite, Dalia; Baumgartner, Livia; Stich, Hans-Bernd; Wessels, Martin; Martin-Creuzburg, Dominik; Spaak, Piet

    2015-08-01

    Biological invasions are a global issue with far-reaching consequences for single species, communities and whole ecosystems. Our understanding of modes and mechanisms of biological invasions requires knowledge of the genetic processes associated with successful invasions. In many instances, this information is particularly difficult to obtain as the initial phases of the invasion process often pass unnoticed and we rely on inferences from contemporary population genetic data. Here, we combined historic information with the genetic analysis of resting eggs to reconstruct the invasion of Daphnia pulicaria into Lower Lake Constance (LLC) in the 1970s from the resting egg bank in the sediments. We identified the invader as 'European D. pulicaria' originating from meso- and eutrophic lowland lakes and ponds in Central Europe. The founding population was characterized by extremely low genetic variation in the resting egg bank that increased considerably over time. Furthermore, strong evidence for selfing and/or biparental inbreeding was found during the initial phase of the invasion, followed by a drop of selfing rate to low levels in subsequent decades. Moreover, the increase in genetic variation was most pronounced during early stages of the invasion, suggesting additional introductions during this period. Our study highlights that genetic data covering the entire invasion process from its beginning can be crucial to accurately reconstruct the invasion history of a species. We show that propagule banks can preserve such information enabling the study of population genetic dynamics and sources of genetic variation in successful invasive populations. PMID:26122166

  7. Pulicaria jaubertii E. Gamal-Eldin reduces triacylglyceride content and modifies cellular antioxidant pathways in 3T3-L1 adipocytes.

    Science.gov (United States)

    Al-Naqeb, Ghanya; Rousová, Jana; Kubátová, Alena; Picklo, Matthew J

    2016-06-25

    Levels of obesity in Middle Eastern countries are increasing. Phytochemicals have anti-obesogenic properties as evidenced by prevention of adipocyte differentiation and blocking triacylglyceride (TG) accumulation. In Yemen, Pulicaria jaubertii E. Gamal-Eldin (PJ) is a food additive and a traditional medicine. We tested the hypothesis that phytochemicals present in PJ inhibit adipocytic responses during differentiation of 3T3-L1 preadipocytes to adipocytes. Methanolic extracts of PJ did not block expression of fatty acid binding protein 4 (FABP4) a marker of differentiation but did inhibit TG accumulation. Treatment of 3T3-L1 preadipocytes increased NADPH:quinone oxidoreductase 1 (NQO1), a suppressor of TG accumulation. Further fractionation of the methanolic PJ extract with hexane and dichloromethane (DCM) demonstrated that bioactivity towards TG reduction and elevated expression of NQO1 and other antioxidant genes (glutamate cysteine ligase catalytic unit, glutathione disulfide reductase, glutathione peroxidase (GPx) 4 resided in the DCM fraction. Activity towards depleting GSH and elevating the expression of catalase and GPx3 were found in the DCM and hexane fractions. Analysis by gas chromatography and liquid chromatography coupled with mass spectrometry demonstrated the presence of catechin-like moieties in the DCM and methanolic fractions and suggest that these components were partially responsible for the bioactivity of these fractions. In summary, our data indicate that fractions derived PJ exhibit anti-adipogenic properties in part through the presence of catechin-like compounds.

  8. The genetic legacy of polyploid Bolivian Daphnia: the tropical Andes as a source for the North and South American D. pulicaria complex.

    Science.gov (United States)

    Mergeay, Joachim; Aguilera, Ximena; Declerck, Steven; Petrusek, Adam; Huyse, Tine; De Meester, Luc

    2008-04-01

    We investigated genetic variation in asexual polyploid members of the water flea Daphnia pulex complex from a set of 12 Bolivian high-altitude lakes. We used nuclear microsatellite markers to study genetic relationships among all encountered multilocus genotypes, and combined this with a phylogenetic approach using DNA sequence data of three mitochondrial genes. Analyses of mitochondrial gene sequence divergence showed the presence of three very distinct clades that likely represent cryptic undescribed species. Our phylogenetic results suggest that the Daphnia pulicaria group, a complex of predominantly North American species that has diversified rapidly since the Pleistocene, has its origin in South America, as specific tests of topology indicated that all three South American lineages are ancestral to the North American members of this species group. A comparison between variation of nuclear and mitochondrial markers revealed that closely related polyploid nuclear genotypes sometimes belonged to very divergent mitochondrial lineages, while distantly related nuclear genotypes often belonged to the same mitochondrial lineage. This discrepancy suggests that these South American water fleas originated through reciprocal hybridization between different endemic, sexually reproducing parental lineages. It is also likely that polyploidy of the investigated lineages resulted from this hybridization. Nevertheless, no putative diploid parental lineages were found in the studied region.

  9. 2D 1H -13C Heteronuclear Shift Correlation Of 2a - Hydroxy Aiantolactone From Pulicaria Undulata C.A. Mey

    Directory of Open Access Journals (Sweden)

    A. Rustaiyan

    1992-07-01

    Full Text Available We have reported recently the isolation and characterization of several sesquiterpene lactones from Pulicaria undulata (1."nThe lactones were isolated from an Et20 - Petrol (1:3 fraction by different chromatographic techniques including HPLC (RP 8, MeOH - H2O, 13:7."nIn this way three eudesmanolides 1 - 3, a guaianolide 4, a nor -guaianolide 5, as well as the pseudoguaianolide 6 and the xanthanolide 7 were isolated. One of the eudesmanolides (2a - hydroxy aiantolactone, 1, was present as the main component."nSuch lactones being known as biologically active substances, we have decided to describe for the first time a detailed interpretation of proton, 1H -NMR, 13C - NMR and 2D lH -13C - heteronuclear shift correlation spectra of 2a - hydroxy aiantolactone. The stereochemistry of C - 2 , C - 7 and C - 8 was determined by the NOESY experiments, H - 7 and H - 8 are in the a configuration and H - 2 is in the b configuration.

  10. 藏药臭蚤草中11个倍半萜化学成分研究%Sesquiterpenoids from Tibetan Folk Drug Pulicaria insignis

    Institute of Scientific and Technical Information of China (English)

    黄圣卓; 蒋思萍; 朱华结

    2010-01-01

    首次进行中国特有菊科藏药臭蚤草(Pulicaria insignis Drumm.ex Dunn)的化学成分研究,从全草中分离得到11个倍半萜类化合物,通过渡谱数据分析分别鉴定为Xanthanolide(1),(3αR,4αR,5R,7αS,9αS)-5-Hy-droxy-5-methyl-3,8-dimethylenedecahydroazuleno[6,5-β]furan-2(3H)-one(2)10α-Hydroxy-14H-inuviscolide(3),(3R,3αR,4αS,7αS,8S,9αS)-3,4α,8-Trimethyldecahydroazuleno[6,5-β]furan-2,5-dione(4)8-Epi-conferti(5),(3αR,5S,11αS,E)-5-Hydroxy-10-methyl-3,6-dimethylene-3α,4,5,6,7,8,11,11α-octahydrocyclodeca[α]furan-2 (3H)-one(6),(3αR,8αR,9αR)-5,8α-Dimethyl-3-methylene-3α,4,8,8α,9,9α-hexahydronaphtho[2,3-β]furan-2,6 (3H,7H)-dione(7),Pterodonoic acid(8),8-Epi-isovangustin(9),(3αR,4αS,8R,8αR,9αR)-8-Hydroxy-5,8α-dime-thyl-3-methylene-3,3α,4,4α,8,8α,9,9α-octahydronaphtho[2,3-β]furan-2(7H)-one(10),(5S,8αR,9αR)-3-(Hydroxymethyl)-5,8α-dimethyl-6,7,8,8α,9,9α-hexahydronaphtho[2,3-β]furan-2(5H)-one(11).所有化合物均首次从该植物中分离得到,同时补充了文献中化合物6和9所缺少的碳谱数据.

  11. Insecticide activity of essential oils of Mentha longifolia, Pulicaria gnaphalodes and Achillea wilhelmsii against two stored product pests, the flour beetle, Tribolium castaneum, and the cowpea weevil, Callosobruchus maculatus.

    Science.gov (United States)

    Khani, Abbas; Asghari, Javad

    2012-01-01

    Essential oils extracted from the foliage of Mentha longifolia (L.) (Lamiales: Lamiaceae) and Pulicaria gnaphalodes Ventenat (Asterales: Asteraceae), and flowers of Achillea wilhelmsii C. Koch (Asterales: Asteraceae) were tested in the laboratory for volatile toxicity against two storedproduct insects, the flour beetle, Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) and the cowpea weevil, Callosobruchus maculatus F. (Coleoptera: Bruchidae). The chemical composition of the isolated oils was examined by gas chromatography-mass spectrometry. InM longifolia, the major compounds were piperitenon (43.9%), tripal (14.3%), oxathiane (9.3%), piperiton oxide (5.9%), and d-limonene (4.3%). In P. gnaphalodes, the major compounds were chrysanthenyl acetate (22.38%), 2L -4L-dihydroxy eicosane (18.5%), verbenol (16.59%), dehydroaromadendrene (12.54%), β-pinen (6.43%), and 1,8 cineol (5.6%). In A. wilhelmsii, the major compounds were 1,8 cineole (13.03%), caranol (8.26%), alpha pinene (6%), farnesyl acetate (6%), and p-cymene (6%). C maculatus was more susceptible to the tested plant products than T castaneum. The oils of the three plants displayed the same insecticidal activity against C. maculatus based on LC(50) values (between 1.54µl/L air in P. gnaphalodes, and 2.65 µl/L air in A. wilhelmsii). While the oils of A. wilhelmsii and M. longifolia showed the same strong insecticidal activity against T. castaneum (LC(50) = 10.02 and 13.05 µl/L air, respectively), the oil of P. gnaphalodes revealed poor activity against the insect (LC(50) = 297.9 µl/L air). These results suggested that essential oils from the tested plants could be used as potential control agents for stored-product insects.

  12. Bacterioplankton communities of Crater Lake, OR: Dynamic changes with euphotic zone food web structure and stable deep water populations

    Science.gov (United States)

    Urbach, E.; Vergin, K.L.; Larson, G.L.; Giovannoni, S.J.

    2007-01-01

    The distribution of bacterial and archaeal species in Crater Lake plankton varies dramatically over depth and with time, as assessed by hybridization of group-specific oligonucleotides to RNA extracted from lakewater. Nonmetric, multidimensional scaling (MDS) analysis of relative bacterial phylotype densities revealed complex relationships among assemblages sampled from depth profiles in July, August and September of 1997 through 1999. CL500-11 green nonsulfur bacteria (Phylum Chloroflexi) and marine Group I crenarchaeota are consistently dominant groups in the oxygenated deep waters at 300 and 500 m. Other phylotypes found in the deep waters are similar to surface and mid-depth populations and vary with time. Euphotic zone assemblages are dominated either by ??-proteobacteria or CL120-10 verrucomicrobia, and ACK4 actinomycetes. MDS analyses of euphotic zone populations in relation to environmental variables and phytoplankton and zooplankton population structures reveal apparent links between Daphnia pulicaria zooplankton population densities and microbial community structure. These patterns may reflect food web interactions that link kokanee salmon population densities to community structure of the bacterioplankton, via fish predation on Daphnia with cascading consequences to Daphnia bacterivory and predation on bacterivorous protists. These results demonstrate a stable bottom-water microbial community. They also extend previous observations of food web-driven changes in euphotic zone bacterioplankton community structure to an oligotrophic setting. ?? 2007 Springer Science+Business Media B.V.

  13. Variability of kokanee and rainbow trout food habits, distribution, and population dynamics, in an ultraoligotrophic lake with no manipulative management

    Science.gov (United States)

    Buktenica, M.W.; Girdner, S.F.; Larson, G.L.; McIntire, C.D.

    2007-01-01

    Crater Lake is a unique environment to evaluate the ecology of introduced kokanee and rainbow trout because of its otherwise pristine state, low productivity, absence of manipulative management, and lack of lotic systems for fish spawning. Between 1986 and 2004, kokanee displayed a great deal of variation in population demographics with a pattern that reoccurred in about 10 years. We believe that the reoccurring pattern resulted from density dependent growth, and associated changes in reproduction and abundance, driven by prey resource limitation that resulted from low lake productivity exacerbated by prey consumption when kokanee were abundant. Kokanee fed primarily on small-bodied prey from the mid-water column; whereas rainbow trout fed on large-bodied prey from the benthos and lake surface. Cladoceran zooplankton abundance may be regulated by kokanee. And kokanee growth and reproductive success may be influenced by the availability of Daphnia pulicaria, which was absent in zooplankton samples collected annually from 1990 to 1995, and after 1999. Distribution and diel migration of kokanee varied over the duration of the study and appeared to be most closely associated with prey availability, maximization of bioenergetic efficiency, and fish density. Rainbow trout were less abundant than were kokanee and exhibited less variation in population demographics, distribution, and food habits. There is some evidence that the population dynamics of rainbow trout were in-part related to the availability of kokanee as prey. ?? 2007 Springer Science+Business Media B.V.

  14. Thermal variation and factors influencing vertical migration behavior in Daphnia populations.

    Science.gov (United States)

    Glaholt, Stephen P; Kennedy, Meghan L; Turner, Elizabeth; Colbourne, John K; Shaw, Joseph R

    2016-08-01

    The antipredator behavior diel vertical migration (DVM), common in aquatic keystone species Daphnia, involves daily migration from warmer surface waters before dawn to cooler deeper waters after dusk. Plasticity in Daphnia DVM behavior optimizes fitness via trade-offs between growth, reproduction, and predator avoidance. Migration behavior is affected by co-varying biotic and abiotic factors, including light, predator cues, and anthropogenic stressors making it difficult to determine each factor's individual contribution to the variation in this behavior. This study aims to better understand this ecologically significant behavior in Daphnia by: (1) determining how Daphnia pulicaria thermal preferences vary within and among natural populations; (2) distinguishing the role of temperature verses depth in Daphnia vertical migration; and (3) defining how two anthropogenic stressors (copper and nickel) impact Daphnia migratory behavior. Simulated natural lake stratification were constructed in 8L (0.5m tall, 14.5cm wide) water columns to monitor under controlled laboratory conditions the individual effects of temperature gradients, depth, and metal stressors on Daphnia vertical migration. Three major findings are reported. First, while no difference in thermal preference was found among the four populations studied, within lake populations variability among isolates was high. Second, decoupling temperature and depth revealed that depth was a better predictor of Daphnia migratory patterns over temperature. Third, exposure to environmentally relevant concentrations of copper or nickel inhibited classic DVM behavior. These findings revealed the high variability in thermal preference found within Daphnia populations, elucidated the individual roles that depth and temperature have on migratory behavior, and showed how copper and nickel can interfere with the natural response of Daphnia to fish predator cues. Thus contributing to the body of knowledge necessary to predict how

  15. Thermal variation and factors influencing vertical migration behavior in Daphnia populations.

    Science.gov (United States)

    Glaholt, Stephen P; Kennedy, Meghan L; Turner, Elizabeth; Colbourne, John K; Shaw, Joseph R

    2016-08-01

    The antipredator behavior diel vertical migration (DVM), common in aquatic keystone species Daphnia, involves daily migration from warmer surface waters before dawn to cooler deeper waters after dusk. Plasticity in Daphnia DVM behavior optimizes fitness via trade-offs between growth, reproduction, and predator avoidance. Migration behavior is affected by co-varying biotic and abiotic factors, including light, predator cues, and anthropogenic stressors making it difficult to determine each factor's individual contribution to the variation in this behavior. This study aims to better understand this ecologically significant behavior in Daphnia by: (1) determining how Daphnia pulicaria thermal preferences vary within and among natural populations; (2) distinguishing the role of temperature verses depth in Daphnia vertical migration; and (3) defining how two anthropogenic stressors (copper and nickel) impact Daphnia migratory behavior. Simulated natural lake stratification were constructed in 8L (0.5m tall, 14.5cm wide) water columns to monitor under controlled laboratory conditions the individual effects of temperature gradients, depth, and metal stressors on Daphnia vertical migration. Three major findings are reported. First, while no difference in thermal preference was found among the four populations studied, within lake populations variability among isolates was high. Second, decoupling temperature and depth revealed that depth was a better predictor of Daphnia migratory patterns over temperature. Third, exposure to environmentally relevant concentrations of copper or nickel inhibited classic DVM behavior. These findings revealed the high variability in thermal preference found within Daphnia populations, elucidated the individual roles that depth and temperature have on migratory behavior, and showed how copper and nickel can interfere with the natural response of Daphnia to fish predator cues. Thus contributing to the body of knowledge necessary to predict how

  16. Promoting Population

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    THE world's population reached 5 billion in 1987,then 6 billion in 1999;now,in 2011,it is 7 billion.For a country with a set birth control policy,the way in which Chinese people and the media view this number has greatly changed.People are increasingly reflecting on the concept of population from a more scientific and rational perspective.This shift is a change from how people perceived population in the past.

  17. Population Blocks.

    Science.gov (United States)

    Smith, Martin H.

    1992-01-01

    Describes an educational game called "Population Blocks" that is designed to illustrate the concept of exponential growth of the human population and some potential effects of overpopulation. The game material consists of wooden blocks; 18 blocks are painted green (representing land), 7 are painted blue (representing water); and the remaining…

  18. Imaginary populations

    Directory of Open Access Journals (Sweden)

    A. Martínez–Abraín

    2010-01-01

    Full Text Available A few years ago, Camus & Lima (2002 wrote an essay to stimulate ecologists to think about how we define and use a fundamental concept in ecology: the population. They concluded, concurring with Berryman (2002, that a population is "a group of individuals of the same species that live together in an area of sufficient size to permit normal dispersal and/or migration behaviour and in which population changes are largely the results of birth and death processes". They pointed out that ecologists often forget "to acknowledge that many study units are neither natural nor even units in terms of constituting a population system", and hence claimed that we "require much more accuracy than in past decades in order to be more effective to characterize populations and predict their behaviour". They stated that this is especially necessary "in disciplines such as conservation biology or resource pest management, to avoid reaching wrong conclusions or making inappropriate decisions". As a population ecologist and conservation biologist I totally agree with these authors and, like them, I be¬lieve that greater precision and care is needed in the use and definition of ecological terms. The point I wish to stress here is that we ecologists tend to forget that when we use statistical tools to infer results from our sample to a population we work with what statisticians term "imaginary", "hypothetical" or "potential" popula¬tions. As Zar (1999 states, if our sample data consist of 40 measurements of growth rate in guinea pigs "the population about which conclusions might be drawn is the growth rates of all the guinea pigs that conceivably might have been administered the same food supplement under identical conditions". Such a population does not really exist, and hence it is considered a hypothetical or imaginary population. Compare that definition with the population concept that would be in our minds when performing such measurements. We would probably

  19. Population policy.

    Science.gov (United States)

    1987-03-01

    Participants in the Seminar on Population Policies for Top-level Policy Makers and Program Managers, meeting in Thailand during January 1987, examined the challenges now facing them regarding the implementation of fertility regulation programs in their respective countries -- Bangladesh, China, India, Indonesia, Malaysia, Nepal, Pakistan, the Philippines, the Republic of Korea, and Thailand. This Seminar was organized to coincide with the completion of an Economic and Social Commission for Asia and the Pacific (ESCAP) study investigating the impact and efficiency of family planning programs in the region. Country studies were reviewed at the Seminar along with policy issues about the status of women, incentive and disincentive programs, and socioeconomic factors affecting fertility. In Bangladesh the government recognizes population growth as its top priority problem related to the socioeconomic development of the country and is working to promote a reorientation strategy from the previous clinic-oriented to a multidimensional family welfare program. China's family planning program seeks to postpone marraige, space the births of children between 3-5 years, and promote the 1-child family. Its goal is to reduce the rate of natural increase from 12/1000 in 1978 to 5/1000 by 1985 and 0 by 2000. India's 7th Five-Year-Plan (1986-90) calls for establishing a 2-child family norm by 2000. In Indonesia the government's population policy includes reducing the rate of population growth, achieving a redistribution of the population, adjusting economic factors, and creating prosperous families. The government of Indonesia reversed its policy to reduce the population growth rate in 1984 and announced its goal of achieving a population of 70 million by 2100 in order to support mass consumption industries. It has created an income tax deduction system favoring large families and maternity benefits for women who have up to 5 children as incentives. Nepal's official policy is to

  20. Population policy.

    Science.gov (United States)

    1987-03-01

    Participants in the Seminar on Population Policies for Top-level Policy Makers and Program Managers, meeting in Thailand during January 1987, examined the challenges now facing them regarding the implementation of fertility regulation programs in their respective countries -- Bangladesh, China, India, Indonesia, Malaysia, Nepal, Pakistan, the Philippines, the Republic of Korea, and Thailand. This Seminar was organized to coincide with the completion of an Economic and Social Commission for Asia and the Pacific (ESCAP) study investigating the impact and efficiency of family planning programs in the region. Country studies were reviewed at the Seminar along with policy issues about the status of women, incentive and disincentive programs, and socioeconomic factors affecting fertility. In Bangladesh the government recognizes population growth as its top priority problem related to the socioeconomic development of the country and is working to promote a reorientation strategy from the previous clinic-oriented to a multidimensional family welfare program. China's family planning program seeks to postpone marraige, space the births of children between 3-5 years, and promote the 1-child family. Its goal is to reduce the rate of natural increase from 12/1000 in 1978 to 5/1000 by 1985 and 0 by 2000. India's 7th Five-Year-Plan (1986-90) calls for establishing a 2-child family norm by 2000. In Indonesia the government's population policy includes reducing the rate of population growth, achieving a redistribution of the population, adjusting economic factors, and creating prosperous families. The government of Indonesia reversed its policy to reduce the population growth rate in 1984 and announced its goal of achieving a population of 70 million by 2100 in order to support mass consumption industries. It has created an income tax deduction system favoring large families and maternity benefits for women who have up to 5 children as incentives. Nepal's official policy is to

  1. Population neuroscience.

    Science.gov (United States)

    Paus, T

    2016-01-01

    Population neuroscience endeavors to identify influences shaping the human brain from conception onwards, thus generating knowledge relevant for building and maintaining brain health throughout the life span. This can be achieved by studying large samples of participants drawn from the general population and evaluated with state-of-the-art tools for assessing (a) genes and their regulation; (b) external and internal environments; and (c) brain properties. This chapter reviews the three elements of population neuroscience (principles, tools, innovations, limitations), and discusses future directions in this field. PMID:27637950

  2. Population dynamics

    Directory of Open Access Journals (Sweden)

    Cooch, E. G.

    2004-06-01

    Full Text Available Increases or decreases in the size of populations over space and time are, arguably, the motivation for much of pure and applied ecological research. The fundamental model for the dynamics of any population is straightforward: the net change over time in the abundance of some population is the simple difference between the number of additions (individuals entering the population minus the number of subtractions (individuals leaving the population. Of course, the precise nature of the pattern and process of these additions and subtractions is often complex, and population biology is often replete with fairly dense mathematical representations of both processes. While there is no doubt that analysis of such abstract descriptions of populations has been of considerable value in advancing our, there has often existed a palpable discomfort when the ‘beautiful math’ is faced with the often ‘ugly realities’ of empirical data. In some cases, this attempted merger is abandoned altogether, because of the paucity of ‘good empirical data’ with which the theoretician can modify and evaluate more conceptually–based models. In some cases, the lack of ‘data’ is more accurately represented as a lack of robust estimates of one or more parameters. It is in this arena that methods developed to analyze multiple encounter data from individually marked organisms has seen perhaps the greatest advances. These methods have rapidly evolved to facilitate not only estimation of one or more vital rates, critical to population modeling and analysis, but also to allow for direct estimation of both the dynamics of populations (e.g., Pradel, 1996, and factors influencing those dynamics (e.g., Nichols et al., 2000. The interconnections between the various vital rates, their estimation, and incorporation into models, was the general subject of our plenary presentation by Hal Caswell (Caswell & Fujiwara, 2004. Caswell notes that although interest has traditionally

  3. Stellar Populations

    Science.gov (United States)

    Peletier, Reynier F.

    2013-10-01

    This is a summary of my lectures during the 2011 Canary Islands Winter School in Puerto de la Cruz. I give an introduction to the field of stellar populations in galaxies, and highlight some new results. Since the title of the Winter School is Secular Evolution in Galaxies I mostly concentrate on nearby galaxies, which are best suited to study this theme. Of course, the understanding of stellar populations is intimately connected to understanding the formation and evolution of galaxies, one of the great outstanding problems of astronomy. We are currently in a situation where very large observational advances have been made in recent years. Galaxies have been detected up to a redshift of ten. A huge effort has to be made so that stellar population theory can catch up with observations. Since most galaxies are far away, information about them has to come from stellar population synthesis of integrated light. Here I will discuss how stellar evolution theory, together with observations in our Milky Way and Local Group, are used as building blocks to analyse these integrated stellar populations.

  4. Stellar Populations

    NARCIS (Netherlands)

    Peletier, Reynier F.

    2013-01-01

    This is a summary of my lectures during the 2011 Canary Islands Winter School in Puerto de la Cruz. I give an introduction to the field of stellar populations in galaxies, and highlight some new results. Since the title of the Winter School is Secular Evolution in Galaxies I mostly concentrate on ne

  5. Population success.

    Science.gov (United States)

    1982-01-01

    "The commitment to population programs is now widespread," says Rafael Salas, Executive Director of the UNFPA, in its report "State of World Population." About 80% of the total population of the developing world live in countries which consider their fertility levels too high and would like them reduced. An important impetus came from the World Conference of 1974. The Plan of Action from the conference projected population growth rates in developing countries of 2.0% by 1985. Today it looks as though this projection will be realized. While in 1969, for example, only 26 developing countries had programs aimed at lowering or maintaining fertility levels, by 1980 there were 59. The International Population Conference, recently announced by the UN for 1984, will, it is hoped, help sustain that momentum. Cuba is the country which has shown the greatest decline in birth rate so far. The birth rate fell 47% between 1965-1970 and 1975-1980. Next came China with a 34% decline in the same period. After these came a group of countries--each with populations of over 10 million--with declines of between 15 and 25%: Chile, Colombia, India, Indonesia, the Republic of Korea, Malaysia and Thailand. Though birth rates have been dropping significantly the decline in mortality rates over recent years has been less than was hoped for. The 1974 conference set 74 years as the target for the world's average expectation of life, to be reached by the year 2000. But the UN now predicts that the developing countries will have only reached 63 or 64 years by then. High infant and child mortality rates, particularly in Africa, are among the major causes. The report identifies the status of women as an important determinant of family size. Evidence from the UNFPA-sponsored World Fertility Survey shows that in general the fertility of women decreases as their income increases. It also indicates that women who have been educated and who work outside the home are likely to have smaller families

  6. Population Aging

    OpenAIRE

    Weil, David N.

    2006-01-01

    Population aging is primarily the result of past declines in fertility, which produced a decades long period in which the ratio of dependents to working age adults was reduced. Rising old-age dependency in many countries represents the inevitable passing of this %u201Cdemographic dividend.%u201D Societies use three methods to transfer resources to people in dependent age groups: government, family, and personal saving. In developed countries, families are predominant in supporting children, w...

  7. Indian populations

    CERN Multimedia

    Spahni,J

    1974-01-01

    Le Prof. J.C. Spahni qui a parcouru les Andes, Vénezuela etc. parle de ses expériences et connaissances qu'il a vécu au cours des 14 ans parmi les populations indiennes de la Cordillière des Andes. Il a ramené des objets artisanals indiens lesquels l'auditoire peut acquérir. L'introduction-conférence est suivi d'un film, commenté par lui-même; après l'entracte il y un débat-dialogue avec le public.

  8. Population Genetics with Fluctuating Population Sizes

    CERN Document Server

    Chotibut, Thiparat

    2016-01-01

    Standard neutral population genetics theory with a strictly fixed population size has important limitations. An alternative model that allows independently fluctuating population sizes and reproduces the standard neutral evolution is reviewed. We then study a situation such that the competing species are neutral at the equilibrium population size but population size fluctuations nevertheless favor fixation of one species over the other. In this case, a separation of timescales emerges naturally and allows adiabatic elimination of a fast population size variable to deduce the fluctuations-induced selection dynamics near the equilibrium population size. The results highlight the incompleteness of the standard population genetics with a strictly fixed population size.

  9. Population, Population Density, and Technological Change

    OpenAIRE

    Klasen, Stephan; Nestmann, Thorsten

    2004-01-01

    In a model on population and endogenous technological change, Kremer combines a short-run Malthusian scenario where income determines the population that can be sustained, with the Boserupian insight that greater population spurs technological change and can therefore lift a country out of its Malthusian trap. We show that a more realistic version of the model, which combines population and population density, allows deeper insights into these processes. The incorporation of population densit...

  10. Education Vital Signs: Population.

    Science.gov (United States)

    Zakariya, Sally Banks

    1985-01-01

    Population changes and demographics shape the future of public schools. Includes statistics on ethnic makeup of student population, the projected baby boomlet, children of working mothers, households without children, and the aging population. (MD)

  11. Simulating Population Growth.

    Science.gov (United States)

    Byington, Scott

    1997-01-01

    Presents a strategy to help students grasp the important implications of population growth. Involves an interactive demonstration that allows students to experience exponential and logistic population growth followed by a discussion of the implications of population-growth principles. (JRH)

  12. Pulicaria undulata: A Potential Phytochemical, Antimicrobial and Antioxidant Source

    International Nuclear Information System (INIS)

    Phytochemical analysis, antimicrobial and antioxidant activities of petroleum ether, chloroform, methanol and aqueous extracts of the plant Pulicari aundulata (L.) C. A. Myer was carried out by using various techniques. The phytochemical analysis of the plant material showed the presence of alkaloids (15.53 percentage), flavonoids (15.81 percentage), phenols (18.91 percentage), saponins (12.13 percentage) and tannins (6.42 percentage). Antimicrobial activity indicated that methanolic extract showed maximum antibacterial potential 44 ± 3.05 mm against P. aureginosa, chloroform extract 39 ± 0.5 mm and petroleum ether extract 37 ± 2.6 mm against S. aureus. The petroleum ether extract showed maximum zone of inhibition of antifungal potential by A. niger which was 32 ± 1.1 mm. The MIC assay was carried out for further analysis which showed the MIC value of methanolic extract was 0.051 ± 0.1 at 1 mg/ml against P. aureginosa and the MIC value against A. niger was 0.52 ± 0.22 at 0.2 mg/ml. Antioxidant potential was determined by using four methods 1,1-diphenyl-2- picrylhydrazyl radical scavenging activity (DPPH), total antioxidant activity (TAA), total phenolic contents (TPC) and metal chelating activity (MC). The aqueous extract showed highest value of percentage DPPH 73.55 percentage at 250 μg/ml and the IC50 value of aqueous extract was 214.45 ± 0.67. The maximum values of total antioxidant activity (3.607 ± 0.33) was observed by aqueous extract, total phenolic content (11.76 ± 2.1) by chloroform and metal chelating activity (64.19 ± 1.5) by aqueous extract. (author)

  13. Estimating Population Dynamics without Population Data

    OpenAIRE

    Robert Chambers; Vangelis Tzouvelekas

    2012-01-01

    We develop a biologically correct cost system for production systems facing invasive pests that allows the estimation of population dynamics without a priori knowledge of their true values. We apply that model to a data set for olive producers in Crete and derive from it predictions about the underlying populations dynamics. Those dynamics are compared to information on population dynamics obtained from pest sampling with extremely favorable results.

  14. Human Population Problems

    Science.gov (United States)

    Emmel, Thomas C.; Sligh, Michael M.

    1970-01-01

    Asserts that overpopulation is the most pressing world problem. Topics discussed include population control in primitive societies, population growth and control in modern societies, methods of motivational population control, consequences of no population control, and mass famines during the 1970's in underdeveloped countries. Cities 33…

  15. Some Current Population Trends.

    Science.gov (United States)

    Taeuber, Conrad

    Population trends in the 1960's and early 1970's are examined in this 1972 speech in terms of overall national trends, the growth of metropolitan areas, the rural population, geographic shifts, internal migration, the black population, and living arrangements. It is noted that population growth in the 1960's was unevenly distributed within age…

  16. Glaucoma in Asian Populations

    Science.gov (United States)

    ... Us Donate In This Section Glaucoma In Asian Populations email Send this article to a friend by ... an even more serious problem as the world population and longevity increases. The other major glaucoma type ...

  17. Estimating Ancestral Population Parameters

    OpenAIRE

    Wakeley, J.; Hey, J.

    1997-01-01

    The expected numbers of different categories of polymorphic sites are derived for two related models of population history: the isolation model, in which an ancestral population splits into two descendents, and the size-change model, in which a single population undergoes an instantaneous change in size. For the isolation model, the observed numbers of shared, fixed, and exclusive polymorphic sites are used to estimate the relative sizes of the three populations, ancestral plus two descendent...

  18. Teaching Population Geography.

    Science.gov (United States)

    Carey, George W.; Schwartzberg, Julie

    Written under the sponsorship of the Population Council, with the financial support of the Population Instructional Materials Project, this work is intended to provide the thoughtful teacher of the social sciences with some suggestions and techniques for introducing population study to students in terms of concrete case studies which explore the…

  19. Modeling Exponential Population Growth

    Science.gov (United States)

    McCormick, Bonnie

    2009-01-01

    The concept of population growth patterns is a key component of understanding evolution by natural selection and population dynamics in ecosystems. The National Science Education Standards (NSES) include standards related to population growth in sections on biological evolution, interdependence of organisms, and science in personal and social…

  20. Controlling Population with Pollution

    Science.gov (United States)

    Browne, Joseph

    2010-01-01

    Population models are often discussed in algebra, calculus, and differential equations courses. In this article we will use the human population of the world as our application. After quick looks at two common models we'll investigate more deeply a model which incorporates the negative effect that accumulated pollution may have on population.

  1. [Population policies and population trends in China].

    Science.gov (United States)

    Pressat, R

    1983-04-01

    Although relatively little has been known about the Chinese population in recent centuries, figures are available for more remote times. In the year 2 the Chinese population was recorded at 60 million. In 1928, when the last pre-Revolution census was conducted, China had a population of 475 million. The population was not believed to have grown very much due to internal disorders, war, and foreigh invasion, but the 1953 census counted 582 million to which were added 18 million to include Taiwan and overseas Chinese. The figure of 600 million appears to mark the beginning of concern over demographic problems. The crude birth rate was estimated at 37/1000 and the death rate at 17/1000. The 1953 census was conducted with Soviet aid and was given some publicity. The period 1953-58 was marked by a mortality decline and a steady fertility rate, but the population is believed to have declined from 647 million in 1958 to 643 million in 1962, the end of the Great Leap Forward. A census suppressed until recently gave a total of 694 million for 1964. Population growth was considerable from 1961-66. In the 1st part of the Cultural Revolution from 1966-70, no effort was made to control population growth; in 1971, the crude birth rate was estimated at 30-35/1000, the mortality rate was 8/1000, and the growth rate was 2.6%. 1971-79 marked the 1st phase of birth limitation, which became more pressing with time. The population was counted at 1 billion 8 million in 1982, with a birth rate of 21/1000, a death rate of 6/1000, and a growth rate of 1.5%. Because of China's comprehensive system of population registration, the results of the 1982 census were not completely unexpected. Wide differences in growth rates were noted between provinces, and the minorities grew at a faster rate than the Han majority. Immediately after the Revolution, population was relatively neglected in China in favor of greater attention to economic growth. The 1st warnings about the consequences of overly

  2. [Population programme of China].

    Science.gov (United States)

    Lui, Z

    1982-01-29

    Results of population programs started in China during the last decade have attracted worldwide attention. The Chinese population issues are important due to the following characteristics: 1) China is the most populated country in the world, with over 1 billion people (22% of world population), by the end of 1980; 2) its population is 80% rural; 3) despite improved living conditions that have helped lower the mortality rate from over 20/1000 before Liberation to 10/1000 in the 1960s and finally 6-8/1000 during the last decade, the Chinese population has increased from 540 million soon after Liberation to the current 1 billion, with an average yearly growth rate of 2%; 4) China has a young population, with 36.8% under 14 years old and less than 5% over 65, hence education and employment are big issues; and 5) due to longterm backward economy resulting from feudal and colonial influence before Liberation, efforts in developing a strong Chinese economy have met with many obstacles. The above 5 features of the Chinese population have important bearing on solving China's population problems and in building its economy, developing its society, and realizing its 4 modernizations. Although China is self-sufficient despite its large population, it faces many problems and challenges especially in the areas of educating its young population and subsequent employment. To achieve a strong economy and to improve the welfare of its people, China has put efforts into controlling the size and improving the quality of its population during the past decade. Programs in population control will continue to take priority in China. PMID:12338284

  3. Population education country programmes.

    Science.gov (United States)

    1980-12-01

    Population education country programs in the countries of India, Malaysia, Nepal, the Philippines, and Sri Lanka are reviewed. In India the machinery is beginning to roll for the nationwide implementation of a 3-year national population education project. A variety of strategies will be used at the national and state levels using existing facilities and infrastructure for implementing various aspects of the program. Recommendations and proposed project activities arrived at during 2 workshop/training programs are outlined. The Malaysian population education program recently developed a working draft of the scope, content, and objectives of population education at the primary and lower and upper secondary levels. This working draft is being pretested among teachers and curriculum developers, and, once revised, it will serve as the overall guiding framework for those responsible for preparing curriculum and instructional materials on population education. The population education program in Nepal will be implemented by 3 units: Curriculum, Textbook, Supervision, and Development Center; Tribhuvan University; and Division of Adult Education. The longterm objective is to institutionalize population education in the formal and nonformal education programs including the university. The Population Education Program of the Philippines has prepared a reader in Filipino for grade 3 pupils. Population education in the country has been promoted to a lesser degree in private than in public schools. the Institutional Development Program of the Population Center Foundation conducted a Summer Institute in Instructional Product Development for the primary purpose of institutionalizing population in the social science curriculum at the tertiary level. The population education program of Sri Lanka will undergo a revival in the recently approved 2-year project agreement between Sri Lanka's government and the United Nations Fund for Population Activities.

  4. Understanding Population Health Terminology

    OpenAIRE

    Kindig, David A.

    2007-01-01

    Population health is a relatively new term, with no agreement about whether it refers to a concept of health or a field of study of health determinants. There is debate, sometimes heated, about whether population health and public health are identical or different. Discussions of population health involve many terms, such as outcomes, disparities, determinants, and risk factors, which may be used imprecisely, particularly across different disciplines, such as medicine, epidemiology, economics...

  5. Population and development.

    Science.gov (United States)

    Okita, S

    1989-03-01

    This speech on the life and work of Rafael Salas, who had been the first executive director of the UN Population Fund (UNFPA) and who contributed immensely to global awareness of population as a vital issue, inaugurated the Rafael M. Salas Lecture Series at the UN. Salas was concerned with individual rights and socioeconomic development while maintaining a balance between population and the environment. He built a large multinational assistance program for population activities and increased funding from $2.5 million in 1969 to $175 million to support 2500 projects in 130 developing countries. He organized both the 1974 World Population Conference and the 1984 International Conference on Population. In developing countries malnutrition and poverty are intertwined, lowering productivity and making people prone to diseases. Infant and child mortality rises with the malnutrition of mothers, therefore campaigns modelled after the postwar Japanese efforts are needed to improve nutrition, to train dietitians, and to introduce school lunch programs. Population stabilization could also be achieved in developing countries by raising income levels, although in Latin American countries birth rates have stayed the same despite increasing income. Direct measures are effective in reducing the birth rate: primary school education, increased income, improved nutrition, decline in infant mortality, higher status of women, and decisive governmental population policy. The Club of Rome report The Limits to Growth predicted that sometime in the 21st century a sudden decline in both population and industrial capacity will be reached at the present growth trends. PMID:12282132

  6. The Population Activist's Handbook.

    Science.gov (United States)

    Population Inst., Washington, DC.

    This handbook is a guide to effective action strategies on dealing with overpopulation. Divided into five sections, the book outlines programs, suggests references, and lists resources that are helpful for thinking and for planning action on population issues. Section one focuses on strategies to change the current population policy choices made…

  7. Dimensions of Philippine population.

    Science.gov (United States)

    1980-01-01

    Major findings of a 2 1/2 year research program on Philippine population are presented. The population situation is described with respect to fertility, mortality, life expectancy, migration, labor force, and family formation. Policy recommendations addressing problems in each of these areas are made.

  8. Population Education Regional News.

    Science.gov (United States)

    Population Education in Asia and the Pacific Newsletter, 1985

    1985-01-01

    Discusses: (1) a comparative study on managing population education programs; (2) a South Pacific workshop in which training materials on sex education, family life education, and nutrition-oriented mixed gardening were developed; and (3) a workshop on evaluative research, the focus of national population education programs in Asia. (JN)

  9. Population Education Country Programmes.

    Science.gov (United States)

    Population Education in Asia and the Pacific Newsletter, 1983

    1983-01-01

    Highlights various population education programs in Afghanistan, China, India, Malaysia, Sri Lanka, and Vietnam. Also describes population education programs at primary and secondary levels in Thailand, curriculum and instructional materials development in this country, and teaching units and curriculum outlines developed from a workshop for…

  10. POPULATION TURNING POINT

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Latest census shows structural imbalance of population has replaced explosive growth to become China’s top challenge China’s population grew by less than 1 percent annually in the last decade,but it still remains the world’s largest at 1.37 billion people,according to results

  11. Negative Drift in Populations

    DEFF Research Database (Denmark)

    Lehre, Per Kristian

    2011-01-01

    An important step in gaining a better understanding of the stochastic dynamics of evolving populations, is the development of appropriate analytical tools. We present a new drift theorem for populations that allows properties of their long-term behaviour, e.g. the runtime of evolutionary algorithms...

  12. Population dynamics of reindeer

    Directory of Open Access Journals (Sweden)

    L. M. Baskin

    1990-09-01

    Full Text Available Five types of reindeer populations are distinguished in terms of population dynamics, population density, social structure and migration distance. Differences in the biological rhythms of the populations result in calving occuring 20 days before snow melting in all populations as well as maximal utilization by the deer of young green vegetation in summer. The growth of antlers may serve as a regulatior of biological rhytms. Populations differ in the level of social motivation. Formation of groups of not less than 30-35 animals ensures cooperative protection from insects and management of the group by man. The fidelity to the calving sites, summer ranges and constant migration routes is based on the common orientation reactions of the animals and social attraction. The direction and migration routes are detemined by obligate learning. The dynamics of populations depends on the fertility of 2 and 3 year old females which is determined by feeding conditions in summer and the activity of males during the rut. Migration plays an important role in the population dynamics.

  13. Evolutionary Population Synthesis for Single Stellar Populations

    Institute of Scientific and Technical Information of China (English)

    张奉辉; 韩占文; 李立芳; Jarrod R.Hurley

    2002-01-01

    Using the evolutionary population synthesis technique, we present the latest integrated colours for instantaneous burst single stellar populations (SSPs) of different metallicities and we investigate their colour evolution. Unlike previous research, we adopt the stellar evolutionary models that employ, amongst other things, recent opacities and a revised equation of state (EOS), and include evolutionary processes such as convective overshooting, thermal pulses and dredge-up. The models are used in the convenient form of analytical fitting functions. In addition, we use the BaSeL model for the library of stellar spectra. This model provides an extensive low-resolution theoretical flux distribution and UB VRIJHKLM colours, which have been calibrated empirically or semi-empirically, for a wide range of stellar parameters.

  14. Diversity of Poissonian populations

    Science.gov (United States)

    Eliazar, Iddo I.; Sokolov, Igor M.

    2010-01-01

    Populations represented by collections of points scattered randomly on the real line are ubiquitous in science and engineering. The statistical modeling of such populations leads naturally to Poissonian populations—Poisson processes on the real line with a distinguished maximal point. Poissonian populations are infinite objects underlying key issues in statistical physics, probability theory, and random fractals. Due to their infiniteness, measuring the diversity of Poissonian populations depends on the lower-bound cut-off applied. This research characterizes the classes of Poissonian populations whose diversities are invariant with respect to the cut-off level applied and establishes an elemental connection between these classes and extreme-value theory. The measures of diversity considered are variance and dispersion, Simpson’s index and inverse participation ratio, Shannon’s entropy and Rényi’s entropy, and Gini’s index.

  15. Shifts that divide population

    Science.gov (United States)

    Muneepeerakul, Rachata; Qubbaj, Murad; Aggarwal, Rimjhim; Anderies, John M.; Janssen, Marco

    2014-05-01

    How does a population of organisms in an ecosystem or of people in a society respond to rapid shifts in the environment? Answers to this question are critical to our ability to anticipate and cope with a changing ecohydrological system. We have developed a generic model of adaptation mechanisms, based on replicator dynamics, in which we derive a simple and insightful threshold condition that separates two important types of responses: 'cohesive transition' in which the whole population changes gradually together, and 'population-dividing transition' in which the population splits into two groups with one eventually dominating the other. The threshold depends on the magnitude of the shift and the shape of the fitness landscape. Division in populations can fundamentally alter the functioning of and induce subsequent feedbacks within the system; knowing the condition that gives rise to such division is thus fundamentally important.

  16. Global population growth.

    Science.gov (United States)

    Langmore, J

    1992-07-01

    The global population passed 5 billion in 1987. In the year 2000 the world's population will be more than 6 billion, increasing by 90-100 million each year. About 95% of future demographic growth will take place in developing countries. The number of school age children is projected to increase from 940 million in 1980 to 1280 million by the year 2000. Under current labor force growth projections in developing countries, around 1.6 billion new jobs will have to be created between 1980 and 2025, with nearly 1 billion of them in Asia. Population often increases at a more rapid rate than agricultural growth. Food production per capita has declined in 70 developing countries. Much of the projected population increase will take place in environmentally fragile regions of the developing world. Population pressures contribute to deforestation, desertification, and scarcity of clean water. The United Nations Population Fund has estimated that in Asia over 43% of women not using family planning would like to postpone, space, or limit their childbearing. Over half of the world's couples of reproductive age are now using contraception. Family planning to postpone the first birth and to eliminate late child bearing would reduce both child loss and maternal illness and death. Both infant and maternal mortality are greater with higher order births. Reducing average family size is an effective way of reducing infant and maternal mortality. The World Bank has given high priority to population assistance, with large programs in Bangladesh, Egypt, India, Indonesia, the Philippines, and Thailand. Population assistance provided by the Australian International Development Assistance Bureau totaled about $4.5 million during 1989-90 and is expected to be about $8 million during 1991-92. Australia should increase the proportion of its development assistance budget devoted to population, and family planning programs should increase to around $26 million in line with other major donors.

  17. The population threat.

    Science.gov (United States)

    Teitelbaum, M S

    1992-01-01

    Commentary is provided on the challenges faced by the new Clinton administration in formulating US key foreign policy initiatives. There is an urgent need to provide balanced and effective foreign aid for reducing high fertility rates in the developing world. There is also a need to effectively monitor the large migrations of populations. Over the past 10 years, the US has not been actively practicing world leadership on population issues. 3 changes in 1993 give impetus to redirect foreign policy: 1) the waning influence of fringe groups who controlled population issues; 2) the campaign promises to restore UN population stabilization programs; and 3) the evidence from the Persian Gulf and Yugoslavia that demographic issues require planning and assessment. Global population growth has been concentrated in the past 40 years, in part due to mortality declines and sustained high fertility. Of significance is the rapidness and momentum of growth. A high percentage are and will be children. Urban population is also growing rapidly in high fertility countries. Countries with high fertility and significant rural-to-urban migration also have large international migrations. The evolution of policy since the 1950s, which for the most part ignored population issues, is discussed. The American debates have been charged with emotionalism: about human sexuality, legitimacy of voluntary fertility control, the role and status of women and men, abortion, intergenerational transfer of obligations, ethnic solidarity and the sovereignty of national borders, and the proper roles of the state versus the marketplace. There have been over 200 years of ideological argument over population issues. The Malthusian argument was that large population size did not increase prosperity, and growth should be limited. The Marxist-Leninist position was that contraception was Malthusian, abortion was a woman's right, and population growth was neutral. By late 1970 the Chinese Maoists adopted the moral

  18. Predation and caribou populations

    Directory of Open Access Journals (Sweden)

    Dale R. Seip

    1991-10-01

    Full Text Available Predation, especially wolf (Canis lupus predation, limits many North American caribou (Rangifer tarandus populations below the density that food resources could sustain. The impact of predation depends on the parameters for the functional and numerical response of the wolves, relative to the potential annual increment of the caribou population. Differences in predator-avoidance strategies largely explain the major differences in caribou densities that occur naturally in North America. Caribou migrations that spatially separate caribou from wolves allow relatively high densities of caribou to survive. Non-migratory caribou that live in areas where wolf populations are sustained by alternate prey can be eliminated by wolf predation.

  19. The population threat.

    Science.gov (United States)

    Teitelbaum, M S

    1992-01-01

    Commentary is provided on the challenges faced by the new Clinton administration in formulating US key foreign policy initiatives. There is an urgent need to provide balanced and effective foreign aid for reducing high fertility rates in the developing world. There is also a need to effectively monitor the large migrations of populations. Over the past 10 years, the US has not been actively practicing world leadership on population issues. 3 changes in 1993 give impetus to redirect foreign policy: 1) the waning influence of fringe groups who controlled population issues; 2) the campaign promises to restore UN population stabilization programs; and 3) the evidence from the Persian Gulf and Yugoslavia that demographic issues require planning and assessment. Global population growth has been concentrated in the past 40 years, in part due to mortality declines and sustained high fertility. Of significance is the rapidness and momentum of growth. A high percentage are and will be children. Urban population is also growing rapidly in high fertility countries. Countries with high fertility and significant rural-to-urban migration also have large international migrations. The evolution of policy since the 1950s, which for the most part ignored population issues, is discussed. The American debates have been charged with emotionalism: about human sexuality, legitimacy of voluntary fertility control, the role and status of women and men, abortion, intergenerational transfer of obligations, ethnic solidarity and the sovereignty of national borders, and the proper roles of the state versus the marketplace. There have been over 200 years of ideological argument over population issues. The Malthusian argument was that large population size did not increase prosperity, and growth should be limited. The Marxist-Leninist position was that contraception was Malthusian, abortion was a woman's right, and population growth was neutral. By late 1970 the Chinese Maoists adopted the moral

  20. Modeling Honey Bee Populations.

    Directory of Open Access Journals (Sweden)

    David J Torres

    Full Text Available Eusocial honey bee populations (Apis mellifera employ an age stratification organization of egg, larvae, pupae, hive bees and foraging bees. Understanding the recent decline in honey bee colonies hinges on understanding the factors that impact each of these different age castes. We first perform an analysis of steady state bee populations given mortality rates within each bee caste and find that the honey bee colony is highly susceptible to hive and pupae mortality rates. Subsequently, we study transient bee population dynamics by building upon the modeling foundation established by Schmickl and Crailsheim and Khoury et al. Our transient model based on differential equations accounts for the effects of pheromones in slowing the maturation of hive bees to foraging bees, the increased mortality of larvae in the absence of sufficient hive bees, and the effects of food scarcity. We also conduct sensitivity studies and show the effects of parameter variations on the colony population.

  1. Parallel grid population

    Science.gov (United States)

    Wald, Ingo; Ize, Santiago

    2015-07-28

    Parallel population of a grid with a plurality of objects using a plurality of processors. One example embodiment is a method for parallel population of a grid with a plurality of objects using a plurality of processors. The method includes a first act of dividing a grid into n distinct grid portions, where n is the number of processors available for populating the grid. The method also includes acts of dividing a plurality of objects into n distinct sets of objects, assigning a distinct set of objects to each processor such that each processor determines by which distinct grid portion(s) each object in its distinct set of objects is at least partially bounded, and assigning a distinct grid portion to each processor such that each processor populates its distinct grid portion with any objects that were previously determined to be at least partially bounded by its distinct grid portion.

  2. AMPHIBIAN POPULATION DYNAMICS

    Science.gov (United States)

    Agriculture has contributed to loss of vertebrate biodiversity in many regions, including the U.S. Corn Belt. Amphibian populations, in particular, have experienced widespread and often inexplicable declines, range reductions, and extinctions. However, few attempts have been made...

  3. Market Squid Population Dynamics

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains population dynamics data on paralarvae, juvenile and adult market squid collected off California and the US Pacific Northwest. These data were...

  4. Populated Places of Iowa

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This coverage contains points that represent populated places, ie. cities, towns, villages or any other named place where people live. The coverage was developed...

  5. Bridged Race Population Estimates

    Data.gov (United States)

    U.S. Department of Health & Human Services — Population estimates from "bridging" the 31 race categories used in Census 2000, as specified in the 1997 Office of Management and Budget (OMB) race and ethnicity...

  6. Exploding Increase of Population

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.H. [Sunmoon University, Chonan (Korea)

    2002-03-01

    Until 1650, the population of the world did not increase properly. According to studies of the demography, the annual increase rate of the world population during 2500 years, from 850 B.C. to 1650 A.D., was just 0.07%. Currently, however, the world population, which has exceptionally rapidly increased from 1900, is more than 6 billion as of 2000. After World War II, especially, the increase rate of the population has risen to about 1.8%, so we can use the word, explosion of the population. The explosion of the population accompanies the increase of energy consumption. The energy production of every year cannot sufficiently meet the energy demand, so we can face the grand energy crisis someday. The date might be a someday after 2020. According to the future forecasting of Shell, one of the majors, the peak of oil supply will be between 2015 and 2020. Unless the alternative energy is developed, the whole world will suffer the serious oil crisis.

  7. Extinction of oscillating populations.

    Science.gov (United States)

    Smith, Naftali R; Meerson, Baruch

    2016-03-01

    Established populations often exhibit oscillations in their sizes that, in the deterministic theory, correspond to a limit cycle in the space of population sizes. If a population is isolated, the intrinsic stochasticity of elemental processes can ultimately bring it to extinction. Here we study extinction of oscillating populations in a stochastic version of the Rosenzweig-MacArthur predator-prey model. To this end we develop a WKB (Wentzel, Kramers and Brillouin) approximation to the master equation, employing the characteristic population size as the large parameter. Similar WKB theories have been developed previously in the context of population extinction from an attracting multipopulation fixed point. We evaluate the extinction rates and find the most probable paths to extinction from the limit cycle by applying Floquet theory to the dynamics of an effective four-dimensional WKB Hamiltonian. We show that the entropic barriers to extinction change in a nonanalytic way as the system passes through the Hopf bifurcation. We also study the subleading pre-exponential factors of the WKB approximation. PMID:27078294

  8. Normative population theory.

    Science.gov (United States)

    Cowen, T

    1989-01-01

    This article finds utilitarian and contractarian approaches to solving the problem of optimal population unacceptable. The principles of utility refer to the best population as the one which contains the greatest sum of utility or the one with the highest average utility. Yet Parfits's repugnant conclusion states that these can imply a very large population at a very low standard of living. Cowen's Methuselah's Paradox says that for any possible happy and meaningful life, we can imagine another, much longer life which demonstrates the absurdity of the utility principles. Lewis argues for a conception of well being based upon choices over whole irreducible states of affairs, i.e., an ordinal concept of value. The contractarian approach assumes that we would rationally choose what type of life we were to live if the choice were made without anyone knowing his particular standing in the world--the veil of ignorance. This requires the individuals to choose on the basis of self interest, but gives too much weight to the individuals actually being born. The most promising population theory appears to be the ideal participant method. Simply stated the optimal population is what an individual would prefer if he had to sequentially live out each life in his choice. Further, this method may be able to reduce the difficulties with evaluating alternate populations to the common problem of aggregating disparate preferences.

  9. The bacterium Pantoea stewartii uses two different type III secretion systems to colonize its plant host and insect vector.

    Science.gov (United States)

    Correa, Valdir R; Majerczak, Doris R; Ammar, El-Desouky; Merighi, Massimo; Pratt, Richard C; Hogenhout, Saskia A; Coplin, David L; Redinbaugh, Margaret G

    2012-09-01

    Plant- and animal-pathogenic bacteria utilize phylogenetically distinct type III secretion systems (T3SS) that produce needle-like injectisomes or pili for the delivery of effector proteins into host cells. Pantoea stewartii subsp. stewartii (herein referred to as P. stewartii), the causative agent of Stewart's bacterial wilt and leaf blight of maize, carries phylogenetically distinct T3SSs. In addition to an Hrc-Hrp T3SS, known to be essential for maize pathogenesis, P. stewartii has a second T3SS (Pantoea secretion island 2 [PSI-2]) that is required for persistence in its flea beetle vector, Chaetocnema pulicaria (Melsh). PSI-2 belongs to the Inv-Mxi-Spa T3SS family, typically found in animal pathogens. Mutagenesis of the PSI-2 psaN gene, which encodes an ATPase essential for secretion of T3SS effectors by the injectisome, greatly reduces both the persistence of P. stewartii in flea beetle guts and the beetle's ability to transmit P. stewartii to maize. Ectopic expression of the psaN gene complements these phenotypes. In addition, the PSI-2 psaN gene is not required for P. stewartii pathogenesis of maize and is transcriptionally upregulated in insects compared to maize tissues. Thus, the Hrp and PSI-2 T3SSs play different roles in the life cycle of P. stewartii as it alternates between its insect vector and plant host. PMID:22773631

  10. Quenched effective population size

    CERN Document Server

    Sagitov, Serik; Vatutin, Vladimir

    2010-01-01

    We study the genealogy of a geographically - or otherwise - structured version of the Wright-Fisher population model with fast migration. The new feature is that migration probabilities may change in a random fashion. Applying Takahashi's results on Markov chains with random transition matrices, we establish convergence to the Kingman coalescent, as the population size goes to infinity. This brings a novel formula for the coalescent effective population size (EPS). We call it a quenched EPS to emphasize the key feature of our model - random environment. The quenched EPS is compared with an annealed (mean-field) EPS which describes the case of constant migration probabilities obtained by averaging the random migration probabilities over possible environments.

  11. A "prolife" population delegation?

    Science.gov (United States)

    Holden, Constance

    1984-06-22

    The White House has been circulating drafts of a controversial position paper to be presented at the August 1984 United Nations world population conference in Mexico City. The paper dismisses population growth in developing countries as a cause of unemployment, illegal migration, or famine, and asserts that population programs are no substitute for ending government controls that stifle economic growth. It also contains a strong statement against abortion, states the U.S. position against coercion in family planning, and declares the Reagan administration's resolve not to fund programs advocating abortion. The U.S. stance is expected to antagonize developing countries and isolate the United States at the U.N. conference. PMID:11644140

  12. Constructing populations in biobanking.

    Science.gov (United States)

    Tupasela, Aaro; Snell, Karoliina; Cañada, Jose A

    2015-01-01

    This article poses the question of whether biobanking practices and standards are giving rise to the construction of populations from which various biobanking initiatives increasingly draw on for legitimacy? We argue that although recent biobanking policies encourage various forms of engagement with publics to ensure legitimacy, different biobanks conceptualize their engagement strategies very differently. We suggest that biobanks undertake a broad range of different strategies with regard to engagement. We argue that these different approaches to engagement strategies are contributing to the construction of populations, whereby specific nationalities, communities, societies, patient groups and political systems become imbued or bio-objectified with particular characteristics, such as compliant, distant, positive, commercialized or authoritarian. This bio-objectification process is problematic in relation to policy aspirations ascribed to biobanking engagement since it gives rise to reified notions of different populations. PMID:26194269

  13. Asymetric Pavlovian Populations

    CERN Document Server

    Bournez, Olivier; Cohen, Johanne; Koegler, Xavier; Rabie, Mikael

    2011-01-01

    Population protocols have been introduced by Angluin et al. as a model of networks consisting of very limited mobile agents that interact in pairs but with no control over their own movement. A collection of anonymous agents, modeled by finite automata, interact pairwise according to some rules that update their states. Predicates on the initial configurations that can be computed by such protocols have been characterized as semi-linear predicates. In an orthogonal way, several distributed systems have been termed in literature as being realizations of games in the sense of game theory. We investigate under which conditions population protocols, or more generally pairwise interaction rules, correspond to games. We show that restricting to asymetric games is not really a restric- tion: all predicates computable by protocols can actually be computed by protocols corresponding to games, i.e. any semi-linear predicate can be computed by a Pavlovian population multi-protocol.

  14. Distance Learning for Special Populations

    Science.gov (United States)

    Bates, Rodger A.

    2012-01-01

    Distance education strategies for remotely deployed, highly mobile, or institutionalized populations are reviewed and critiqued. Specifically, asynchronous, offline responses for special military units, Native Americans on remote reservations, prison populations and other geographically, temporally or technologically isolated niche populations are…

  15. Having quality population.

    Science.gov (United States)

    Ramos, F V

    1993-06-01

    This speech was delivered during Population and Development Week in the Philippines. Attention was drawn to population statistics: an annual growth rate of 2.3%, density of 202 persons/sq km, and an expected population of 75 million by the year 2000. Coupled with rapid population growth is the uneven distribution of wealth: the top 20% have over 50% of the total income and the lowest 20% have only 5% of the income. In such a social situation, it is women and children who are the most vulnerable. In cities, unemployment is high due to population growth and the migration of the rural poor. The rural poor living in areas of declining resources also move onto marginal uplands, which adds pressure to the already fragile ecology. Everyone must accept that the nation's problems are due to overpopulation. The government's development plans aim for sustainable growth, poverty alleviation, reduction in equality, generation of job opportunities, and achievement of social justice. People in government are determined to lead the Philippines toward a higher standard comparable with other dynamic Asian neighbors. The strategy is empowerment of the people. THe value is in the welfare of individuals and their families and the welfare of the nation. Couples have the right to manage their family size voluntarily and responsibly. The government's role is to provide adequate information on family planning in accordance with individual's religious convictions. Policies will also be directed to improved access to quality education, child survival, and maternal health, employment opportunities, and access and control over resources for people. There must be fuller participation of women in development. Support for the government's population program is sought from government officials, the private sector, and nongovernmental organizations. All provincial governors, city and municipal mayors, and all local executives will be directed to formulate population plans and to provide family

  16. Befolkningsudviklingen (Population Development)

    DEFF Research Database (Denmark)

    Nørgaard, Jørgen

    2010-01-01

    The article takes the 1972 report, The Limits to Growth as its starting point, briefly explaining the Systam Dynamics model used for the report's analyses. Focus is on the important role of population. The simple model of I = PxAxT, where I is the environmental Impact, P population......, A is the Affluence and T the ecoimpact-intensity of the Technology used. Various scenarios ar shown, illustrating how a choice of 1.6 birth per woman on average instead of 2.6 birth, will in 2150 result in 3.6 billion people on earth instead of 27 billions. The article warns against the believe that growth in GDP...

  17. China Population and Developmenl

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    The Cairo International Conference on Population and Development (ICPD) paid great attention to the sexual and reproductive health of adolescents. One of the top priorities of the ICPD Programme of Action is to provide adolescents with necessary sexual and reproductive health information and services, ensure their right to reproductive health education and services, and help them develop risk-free behaviours and healthy lifestyles.

  18. Population and Development Issues.

    Science.gov (United States)

    Cohen, Sharon; Garran, Christopher

    1998-01-01

    Describes a unit on demographics for a high school world-history course that addresses questions of uneven population growth and the "problem of global overpopulation." Provides a detailed outline of the two-day unit including unit and daily goals and objectives, daily activities and questions, and ideas for further student research. (DSK)

  19. Constructing populations in biobanking

    DEFF Research Database (Denmark)

    Tupasela, Aaro; Snell, Karoliina; Cañada, Jose a.

    2015-01-01

    This article poses the question of whether biobanking practices and standards are giving rise to the construction of populations from which various biobanking initiatives increasingly draw on for legitimacy? We argue that although recent biobanking policies encourage various forms of engagement w...

  20. Reconceptualization of Population Education.

    Science.gov (United States)

    Sikes, O. J.

    1993-01-01

    Discusses eight aspects of the reorganization of population education: (1) need for clear objectives; (2) emerging concerns about content; (3) prioritization of contents; (4) involvement of parents; (5) approaches to teaching; (6) teacher training; (7) evaluation issues; and (8) institutionalization. (MDH)

  1. Charting Population Shifts

    Institute of Scientific and Technical Information of China (English)

    LI LI

    2010-01-01

    @@ China is updating its demographic information through its once-in-adecade population census.The latest database will be used as an important reference for the country to draft its development plan for the next five years and deal with social problems,such as an aging society and imbalanced gender ratio,according to experts.

  2. The Problem of Population

    Institute of Scientific and Technical Information of China (English)

    刘香情; 钱丹

    2002-01-01

    With the population growing, a lot of problems have come out, Nowadays a lot of tall buildings have been built, but the houses are still very short; A lot of cars and buses have increased, but they are still crowded with people; A lot of schools have been built,

  3. Discussion Forum--Population Theories: Their Implications on Population Education.

    Science.gov (United States)

    Population Education in Asia and the Pacific Newsletter, 1983

    1983-01-01

    Contends that unless population education programs have a clear conceptual framework built upon a consistent set of population theories, they will remain merely as appendices to established school projects. Several population theories and their implications for population education are described. These include Malthusian demographic transition,…

  4. [The Marxist outlook on population].

    Science.gov (United States)

    Qin, R

    1984-09-29

    Marxist population theory and world population are discussed. From his study of capitalist population theory Marx concluded, "In capitalist reproduction, poverty produces population," thus rejecting Malthusian population determinism theory and developing economic determinism. According to UN statistics, world population has stabilized since the middle of this century after having doubled every hundred years for the last 300; population in the developed countries showed a positive decrease and average net population growth of the developing countries also decreased. The premise of this paper is that population grows according to social economy development. During the last several hundred years, world wealth increased much faster than population; in the last 200 years alone, the population has increased fivefold, but wealth fortyfold. In addition, world population analysis reveals an inverse relationship between wealth and population in the developed and developing countries: the poorer the country, the greater the population. From this perspective, the study of population must begin with surplus labor. Accumulation of surplus production is the foundation of continuous social development and the basis for population growth. The major difference in methods between capitalist countries and China is that the capitalist-planned fertility affects the individual family while Chinese-planned fertility has the whole nation in mind. Human fertility is determined by the economic system. Private ownership determines the private nature of fertility and public ownership determines the public nature of fertility. Thus population development is determined by the accumulation of social wealth. PMID:12159280

  5. [Vietnam and its population].

    Science.gov (United States)

    Veron, J

    1993-01-01

    Viet Nam's 1993 population of 72 million makes it the second largest country of Southeast Asia after Indonesia. Viet Nam's demographic transition is underway, but growth is still a rapid 2% annually, a sufficiently high rate to hinder socioeconomic development. The 1979 and 1989 censuses and the 1988 Demographic and Health Survey are the major recent sources of data on Viet Nam's population. Marriage is universal in Viet Nam. Men marry at 24.5 and women at 23.2 years on average. Fertility estimates based on nonadjusted census data indicate a total fertility rate for 1988-89 of 3.8 overall, 2.2 in urban areas, and 4.3 in rural areas. Regional differences resulting from contraceptive usage, educational differentials, and tabus regarding spacing are strong. The average household size is 5. Viet Nam's first fertility reduction policy was announced in 1963 and sought to improve the welfare of women to increase their productivity for the war effort. More recent family planning policies are based on the view that rapid demographic growth is one of the great obstacles to development. The objectives of the current policy are to reduce the growth rate to 1% by the end of the century, increase contraceptive prevalence, delay arrival of the first child, limit family size to 2 children or 3 for ethnic minorities, and increase birth intervals from 3 to 5 years. The program is voluntarist in nature but includes incentives and disincentives. Life expectancy at birth in 1989 was 67.5 years for women and 63 for men. Infant mortality was 37/1000, with regional differentials. The principal causes of hospital deaths are tuberculosis, malaria, and diarrhea. Objectives of the current health policy are to prevent infectious diseases, reinforce primary health care services, promote traditional medicine, achieve self-sufficiency in basic medicines, and improve environmental health and access to clean water. Viet Nam is one of the most densely populated Southeast Asian countries and is still

  6. On optimal population paths

    CERN Document Server

    Lane, John S

    1977-01-01

    The overall purpose of this monograph is to integrate and critically evaluate the existing literature in the area of optimal joint savings population programs. The existing diverse presentations are all seen to be discussions within a unified framework. The central problem is to compare the desirability of alternative inter-temporal sequences of total savings and population sizes. Of critical importance is whether one regards persons as the fundamental moral entities or whether one takes Sidgwick's viewpoint that something good being the result of one's action is the baSic reason for dOing anything. The latter viewpoint is consistent with defining a complete social preference ordering over these alternative sequences. Since part of one's interest is to evaluate the consequences of various ethical beliefs a com­ parative study of several such orderings is presented; in particular the Mill-Wolfe average utilitarian, and Sidgwick-Meade classical utilitarian) formulations. A possible problem with the social pref...

  7. Population attribute compression

    Science.gov (United States)

    White, James M.; Faber, Vance; Saltzman, Jeffrey S.

    1995-01-01

    An image population having a large number of attributes is processed to form a display population with a predetermined smaller number of attributes that represent the larger number of attributes. In a particular application, the color values in an image are compressed for storage in a discrete look-up table (LUT). Color space containing the LUT color values is successively subdivided into smaller volumes until a plurality of volumes are formed, each having no more than a preselected maximum number of color values. Image pixel color values can then be rapidly placed in a volume with only a relatively few LUT values from which a nearest neighbor is selected. Image color values are assigned 8 bit pointers to their closest LUT value whereby data processing requires only the 8 bit pointer value to provide 24 bit color values from the LUT.

  8. [Population, ethics and equity].

    Science.gov (United States)

    Berlinguer, G

    1997-01-01

    "Demography is, explicitly and not, imbued with an [ethical] content.... As demography involves both public policies and individual choices, the [ethical] slant should be [examined]. Thus, what we have on the one hand is an [ethical] state, which dictates its citizens' personal behaviour and, on the other, a state based on liberty, backed up by three shared values: human rights, pluralism and equality. This article looks at how today these may be reinterpreted when making decisions regarding the population." (EXCERPT)

  9. [Population, ethics and equity].

    Science.gov (United States)

    Berlinguer, G

    1997-01-01

    "Demography is, explicitly and not, imbued with an [ethical] content.... As demography involves both public policies and individual choices, the [ethical] slant should be [examined]. Thus, what we have on the one hand is an [ethical] state, which dictates its citizens' personal behaviour and, on the other, a state based on liberty, backed up by three shared values: human rights, pluralism and equality. This article looks at how today these may be reinterpreted when making decisions regarding the population." (EXCERPT) PMID:12293335

  10. Population, desertification, and migration.

    Science.gov (United States)

    Westing, A H

    1994-01-01

    When an imbalance develops between population numbers and the carrying capacity of the land, the persons thereby displaced are referred to as environmental refugees. The utilization of the land beyond sustainability leads to land degradation and ultimately, desertification. The social and political impacts of long-term environmental migration can be distinguished: a) at the site of origin of the displaced persons by the residual population; b) at rural sites of destination within the nation between the new arrivals and preestablished populations; c) in the cities within the nation; d) in the nonindustrialized foreign countries; and e) in the industrialized foreign countries. In the event that an area which had previously been devoted to pastoralism is converted to agriculture, the displaced pastoralists might respond through armed rebellion. In some instances, the disenchanted urban squatters become a politically restive and even a destabilizing force, as occurred in Sudan in the 1980s, especially in Khartoum and Port Sudan. The foreign countries to which many of the displaced persons are migrating are subjected to increasing levels of migrant-induced economic, cultural, and political strains. The growing problems associated with south-to-north migration across the Mediterranean Sea have recently led France, Italy, Portugal, and Spain to enter into a consultative arrangement with Algeria, Libya, Mauritania, Morocco, and Tunisia. All foreign aid to the nonindustrialized countries that attempts to ameliorate the problem of desertification must adopt integrated approaches that: a) address population issues; b) support environmental education; c) provide for the protection of biodiversity; d) encourage participatory forms of local and national government; e) provide opportunities for income generation outside the livestock sector; and f) foster political security and facilitate ecogeographical (subregional) cooperation.

  11. Population, environment and development.

    Science.gov (United States)

    Karkal, M

    1994-06-01

    Western development models label subsistence economies, which do not participate in the market economy on a grand scale and do not consume commodities produced for and distributed through the market, to be poor. Yet, subsistence does not always indicate a low quality of life. The Western development process has destroyed wholesome and sustainable lifestyles. In India, the Green Revolution caused many small farmers to lose their land. In comparison to traditional economies, industrial economies have longer technological chains dependent on higher energy and resource inputs and exclude large numbers of people without power to buy goods. Further, they generate new and artificial needs, necessitating increased production of industrial goods and services. They erode resource bases for survival. This erosion is marginalizing people who were traditionally in nature's economy. Developed countries did not deliver 0.15% of their GNP to development projects in developing countries as promised. The US made population growth in these countries its cause. The UN and other multinational agencies during 1962-1972, at the US's request, began to support population and family planning programs in developing countries. These countries opposed the 1st draft at the 1974 Bucharest Population Conference, but by the conference in Mexico City, most supported the need for family planning. Yet, the US politicized this conference and had a greater say in the recommendations than did developing countries. Structural adjustments and external debt repayments required of developing countries in the 1980s set them back. In fact, the number of developing countries increased from 31 to 42. The UN recognizes the right to development, but social inequalities are barriers to this right. If environmental degradation continues, poverty will only increase. Women's groups are playing a great role in preparations for the International Conference on Population and Development in Cairo in September 1994. PMID

  12. [Several problems concerning population investment].

    Science.gov (United States)

    Liu, Z

    1982-07-29

    Population investment is a major topic in the studies of population and economic relations. In this particular area, numerous theoretical and practical problems are still in need of solution. Concerning the problem of population concept, there are three different approaches: (1) to determine the definition of population investment from the relationship between the population growth and the capital from national income used for investment, including investment in the newly increased population and investment in the entire population; (2) to explain population investment from the economic viewpoint that people are producers; and (3) to explain population investment from the expense needed to change a simple labor force to a skillful labor force. The expenses include educational costs, maintanance spending, wages needed to compensate workers in labor, costs for workers to master and learn modern scientific techniques to be used for production, and the costs of keeping a young labor force in the next generation.

  13. High population increase rates.

    Science.gov (United States)

    1991-09-01

    In addition to its economic and ethnic difficulties, the USSR faces several pressing demographic problems, including high population increase rates in several of its constituent republics. It has now become clear that although the country's rigid centralized planning succeeded in covering the basic needs of people, it did not lead to welfare growth. Since the 1970s, the Soviet economy has remained sluggish, which as led to increase in the death and birth rates. Furthermore, the ideology that held that demography could be entirely controlled by the country's political and economic system is contradicted by current Soviet reality, which shows that religion and ethnicity also play a significant role in demographic dynamics. Currently, Soviet republics fall under 2 categories--areas with high or low natural population increase rates. Republics with low rates consist of Christian populations (Armenia, Moldavia, Georgia, Byelorussia, Russia, Lithuania, Estonia, Latvia, Ukraine), while republics with high rates are Muslim (Tadzhikistan, Uzbekistan, Turkmenistan, Kirgizia, Azerbaijan Kazakhstan). The later group has natural increase rates as high as 3.3%. Although the USSR as a whole is not considered a developing country, the later group of republics fit the description of the UNFPA's priority list. Another serious demographic issue facing the USSR is its extremely high rate of abortion. This is especially true in the republics of low birth rates, where up to 60% of all pregnancies are terminated by induced abortions. Up to 1/5 of the USSR's annual health care budget is spent on clinical abortions -- money which could be better spent on the production of contraceptives. Along with the recent political and economic changes, the USSR is now eager to deal with its demographic problems. PMID:12284289

  14. An optimum world population.

    Science.gov (United States)

    Willey, D

    2000-01-01

    The optimum population of the world is the one that is most likely to make the option of a good quality of life available to everyone everywhere, both now and in the future. Establishing a consensus about the size of such a population would be an important step towards achieving it. Estimates of an optimum involve three main steps. First, estimate the maximum (carrying capacity) assuming a specified lifestyle. The main criteria are the maintenance of biodiversity, the availability of freshwater, and the availability of land--for agriculture, forestry and artificial systems but above all for the conversion of energy. (In applying the criteria, there are always two questions to ask: 'What is the maximum amount of consumption that the biosphere can stand?' and 'What is an adequate share of such consumption per person?') Second, convert the maximum (two to three billion) into an optimum by applying a far wider range of criteria, including personal liberty, mobility, recreation and political representation. Third, consider just two criteria (economies of scale and technological innovation) in order to ensure that the optimum (one to two billion) has not fallen below the minimum (half to one billion). The estimates are so low because of the need for a huge increase in median per capita consumption if everyone is to have the option of an adequate material standard of living. Opinion-formers are likely not to take much notice of such estimates, but it is probable that minds will be concentrated by an energy shock some time during the next decade. Achieving an optimum world population will not solve the world's major problems, but it would make them solvable. PMID:10824524

  15. Population policies and development.

    Science.gov (United States)

    Stamper, B M

    1984-01-01

    This article critically examines 4 conceptual frameworks for Third World population policies: the family planning approach, beyond family planning measures, the development hypothesis and transition theory, and the distributive hypothesis and fertility. Although family planning is a basic human right and can lead to lower levels of population and improved maternal-child health, this approach alone does not always have a meaningful demographic impact. If high fertility is economically rational from the family viewpoint, the demand for family planning services will remain marginal. Other policies seek to go beyond the family planning approach and to directly influence the demand for reproductive control through provision of old age support, monetary incentives for reduced fertility or stringent and coercive measures. However, such policies can have adverse distributional effects and directly penalize the children of large families. The demographic transition theory lacks a measurable and specifiable causation mechanism, giving it little predictive value. It may be that economic growth increases fertility in the short run and reduces fertility only over the long run through indirect effects. The key issue is how the rate of growth is distributed across the population. The development and demographic transition hypothesis focuses mainly on aggregate economic and social measures rather than on their underlying distributions. The distributive hypothesis implies policies that promote a greater level of investment in human capital, with a wide distributional emphasis. Diffused investment in human capital is believed to indirectly influence the desire to control fertility. It is concluded that all 4 conceptual frameworks for analyzing fertility-related policies for the Third World are inadequate or seriously flawed. They are not pragmatic, do not identify or assign weights to the crucial causal variables, fail to specify thresholds or critical minimum levels, discount

  16. OZ, POPULISM, AND INTENT

    Directory of Open Access Journals (Sweden)

    Ranjit S. Dighe

    2002-01-01

    Full Text Available Following the lead of influential articles by Henry Littlefield (1964 and Hugh Rockoff (1990, teachers of economic history often relate the Populist movement of the 1890s to L. Frank Baum’s The Wonderful Wizard of Oz. This paper reexamines the inevitable question of whether Baum intended his story as a parable on Populism. From other, more overtly political writing sof Baum’s, and from biographical information about Baum himself, the evidence suggests that Oz was not a Populist parable. We can still profitably read it as one, but we need to separate that interpretation from Baum’s intention.

  17. Playing With Population Protocols

    Directory of Open Access Journals (Sweden)

    Xavier Koegler

    2009-06-01

    Full Text Available Population protocols have been introduced as a model of sensor networks consisting of very limited mobile agents with no control over their own movement: A collection of anonymous agents, modeled by finite automata, interact in pairs according to some rules. Predicates on the initial configurations that can be computed by such protocols have been characterized under several hypotheses. We discuss here whether and when the rules of interactions between agents can be seen as a game from game theory. We do so by discussing several basic protocols.

  18. Diabetes in Population Isolates

    DEFF Research Database (Denmark)

    Grarup, Niels; Moltke, Ida; Albrechtsen, Anders;

    2016-01-01

    Type 2 diabetes (T2D) is an increasing health problem worldwide with particularly high occurrence in specific subpopulations and ancestry groups. The high prevalence of T2D is caused both by changes in lifestyle and genetic predisposition. A large number of studies have sought to identify...... on glucose-stimulated plasma glucose, serum insulin levels, and T2D. The variant defines a specific subtype of non-autoimmune diabetes characterized by decreased post-prandial glucose uptake and muscular insulin resistance. These and other recent findings in population isolates illustrate the value...

  19. Surgery and refugee populations.

    Science.gov (United States)

    Kushner, A L; Groen, R S; Kingham, T P

    2009-01-01

    Although infectious diseases, malnutrition and diarrhea account for the vast majority of deaths in many crisis situations, many individuals also suffer from traumatic injuries and other surgically treatable conditions. Understanding the determinants involved in surgical interventions is facilitated by defining baseline, emergent and chronic phases for refugees and internally displaced populations. International aid organizations often expend vast resources on surgical interventions. More detailed assessments and further study may help provide insight into optimizing the success and minimizing the cost of such interventions. This article is a review of the surgical and disaster literature and defines issues for further study. PMID:19447737

  20. Neoplasms in irradiated populations

    International Nuclear Information System (INIS)

    The paper describes the results of three prospective studies which have been ongoing for 25 years. The study populations include: (1) persons treated with x rays in infancy for alleged enlargement of the thymus gland; (2) persons treated in childhood with x rays and/or radium for lymphoid hyperplasia of the nasopharynx; and (3) women treated with x rays for acute postpartum mastitis. The studies have resulted in the quantification of risk for radiogenic thyroid and breast cancer for periods up to 40 years post irradiation

  1. Density Estimation in Several Populations With Uncertain Population Membership

    KAUST Repository

    Ma, Yanyuan

    2011-09-01

    We devise methods to estimate probability density functions of several populations using observations with uncertain population membership, meaning from which population an observation comes is unknown. The probability of an observation being sampled from any given population can be calculated. We develop general estimation procedures and bandwidth selection methods for our setting. We establish large-sample properties and study finite-sample performance using simulation studies. We illustrate our methods with data from a nutrition study.

  2. Innovations in Population Education: Conveying Population Education through Games.

    Science.gov (United States)

    Villanueva, Carmelita L., Ed.

    1987-01-01

    The use of games and simulations is a method that educators are finding especially useful in presenting information about population concerns. The "Futures Wheels" is a participatory classroom exercise, designed to demonstrate probable consequences of future population increases and is also used to illustrate a wide range of population related…

  3. Correlations and Neuronal Population Information.

    Science.gov (United States)

    Kohn, Adam; Coen-Cagli, Ruben; Kanitscheider, Ingmar; Pouget, Alexandre

    2016-07-01

    Brain function involves the activity of neuronal populations. Much recent effort has been devoted to measuring the activity of neuronal populations in different parts of the brain under various experimental conditions. Population activity patterns contain rich structure, yet many studies have focused on measuring pairwise relationships between members of a larger population-termed noise correlations. Here we review recent progress in understanding how these correlations affect population information, how information should be quantified, and what mechanisms may give rise to correlations. As population coding theory has improved, it has made clear that some forms of correlation are more important for information than others. We argue that this is a critical lesson for those interested in neuronal population responses more generally: Descriptions of population responses should be motivated by and linked to well-specified function. Within this context, we offer suggestions of where current theoretical frameworks fall short.

  4. CDC WONDER: Population (from Census)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Population online databases contain data from the US Census Bureau. The Census Estimates online database contains contains county-level population counts for...

  5. CDC WONDER: Population (from Census)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Population online databases contain data from the US Census Bureau. The Census Estimates online database contains county-level population counts for years 1970...

  6. Lithuanian Population Aging Factors Analysis

    OpenAIRE

    Agnė Garlauskaitė; Rasa Zabarauskaitė

    2015-01-01

    The aim of this article is to identify the factors that determine aging of Lithuania’s population and to assess the influence of these factors. The article shows Lithuanian population aging factors analysis, which consists of two main parts: the first describes the aging of the population and its characteristics in theoretical terms. Second part is dedicated to the assessment of trends that influence the aging population and demographic factors and also to analyse the determinants of the agin...

  7. Population, migration and urbanization.

    Science.gov (United States)

    1982-06-01

    Despite recent estimates that natural increase is becoming a more important component of urban growth than rural urban transfer (excess of inmigrants over outmigrants), the share of migration in the total population growth has been consistently increasing in both developed and developing countries. From a demographic perspective, the migration process involves 3 elements: an area of origin which the mover leaves and where he or she is considered an outmigrant; the destination or place of inmigration; and the period over which migration is measured. The 2 basic types of migration are internal and international. Internal migration consists of rural to urban migration, urban to urban migration, rural to rural migration, and urban to rural migration. Among these 4 types of migration various patterns or processes are followed. Migration may be direct when the migrant moves directly from the village to the city and stays there permanently. It can be circular migration, meaning that the migrant moves to the city when it is not planting season and returns to the village when he is needed on the farm. In stage migration the migrant makes a series of moves, each to a city closer to the largest or fastest growing city. Temporary migration may be 1 time or cyclical. The most dominant pattern of internal migration is rural urban. The contribution of migration to urbanization is evident. For example, the rapid urbanization and increase in urban growth from 1960-70 in the Republic of Korea can be attributed to net migration. In Asia the largest component of the population movement consists of individuals and groups moving from 1 rural location to another. Recently, because urban centers could no longer absorb the growing number of migrants from other places, there has been increased interest in the urban to rural population redistribution. This reverse migration also has come about due to slower rates of employment growth in the urban centers and improved economic opportunities

  8. Population genetics without intraspecific data

    DEFF Research Database (Denmark)

    Thorne, Jeffrey L; Choi, Sang Chul; Yu, Jiaye;

    2007-01-01

    populations, and parameters of interspecific models should have population genetic interpretations. We show, with two examples, how population genetic interpretations can be assigned to evolutionary models. The first example considers the impact of RNA secondary structure on sequence change, and the second...... genetic interpretation. Udgivelsesdato: 2007-Aug...

  9. A Population of Assessment Tasks

    Science.gov (United States)

    Daro, Phil; Burkhardt, Hugh

    2012-01-01

    We propose the development of a "population" of high-quality assessment tasks that cover the performance goals set out in the "Common Core State Standards for Mathematics." The population will be published. Tests are drawn from this population as a structured random sample guided by a "balancing algorithm."

  10. Population of the Galaxy

    International Nuclear Information System (INIS)

    A new theory of the population of the Galaxy, based on the hypothesis of explosive: simultaneous and one-time-origination of life in the universe at a certain moment of its evolutionary development, is discussed in the report. According to the proposed theory, civilizations began to arise around the present moment of the history of the universe. Their possible number is limited even when their lifetime is unlimited. The age and number of simultaneously existing civilizations when their lifetime is unlimited is determined by the duration and dispersion of the time of evolution of life on different planets from the cell level to civilization. The proposed theory explains better than Drake's theory the negative results of the search for evidence of the existence of superpowerful extraterrestrial civilizations and the noncolonization of the earth

  11. Stochastic population theories

    CERN Document Server

    Ludwig, Donald

    1974-01-01

    These notes serve as an introduction to stochastic theories which are useful in population biology; they are based on a course given at the Courant Institute, New York, in the Spring of 1974. In order to make the material. accessible to a wide audience, it is assumed that the reader has only a slight acquaintance with probability theory and differential equations. The more sophisticated topics, such as the qualitative behavior of nonlinear models, are approached through a succession of simpler problems. Emphasis is placed upon intuitive interpretations, rather than upon formal proofs. In most cases, the reader is referred elsewhere for a rigorous development. On the other hand, an attempt has been made to treat simple, useful models in some detail. Thus these notes complement the existing mathematical literature, and there appears to be little duplication of existing works. The authors are indebted to Miss Jeanette Figueroa for her beautiful and speedy typing of this work. The research was supported by the Na...

  12. Population, food and knowledge

    DEFF Research Database (Denmark)

    Strulik, Holger; Weisdorf, Jacob Louis

    2008-01-01

    of population. London, printed for J. Johnson, 1798) so-called preventive check hypothesis-that fertility rates vary inversely with the price of food-the current study offers a new and straightforward explanation for the demographic transition and the break with the Malthusian era. Employing a two......-sector framework with agriculture and industry, we demonstrate how fertility responds differently to productivity and income growth, depending on whether it emerges in agriculture or industry. Agricultural productivity and income growth makes food goods, and therefore children, relatively less expensive....... Industrial productivity and income growth, on the other hand, makes food goods, and therefore children, relatively more expensive. The present framework lends support to existing unified growth theories and is well in tune with historical evidence about structural transformation....

  13. Population and health.

    Science.gov (United States)

    Kwon, E H

    1975-01-01

    Quality of population is as important as quantity when one is discussing public health needs or quality of the labor force. Population quality as measured by physical disease, mental disease, maternal death and morbidity rates, fetal and infant mortality rates, and family size and child health is discussed. Charts give figures for Korea from a variety of sample surveys and census studies for 1973. All developing countries have high child death rates from communicable diseases. Korea, in addition, suffers from several parasitic diseases. The problems of maternal death and morbidity are due to disease, hard physical labor during pregnancy, poorly attended births (26% were attended by a mother or mother-in-law and 11% by friends and relatives), and high parity. Figures show that the danger of childbirth is greatest for the 1st baby, lower for the 2nd and 3rd, then rises, climbing steeply after the 5th birth. Iron deficiency anemia and oxalic acid deficiency together with general malnutrition contribute to high maternal morbidity and mortality and fetal death or improper brain development. It is also well accepted that children from large families have slower physical and mental growth than children in smaller families. Family planning problems can best be solved by integrating birth spacing and birth limitation programs into a total maternal and child health scheme and emphasizing the health aspects of family planning. Maternity-centered family planning is but 1 example of such an integrated approach. This integration will make better use of personnel, result in better program supervision, and will help the mother understand it is in her best interest to practice family planning.

  14. Population and the World Bank.

    Science.gov (United States)

    Sankaran, S

    1973-12-01

    The World Bank Group regards excessive population growth as the single greatest obstacle to economic and social advance in the underdeveloped world. Since 1969 the Bank and the International Development Agency have provided countries with technical assistance through education, fact-finding, and analysis and given 65.7 million dollars for population projects. These projects, in India, Indonesia, Iran, Jamaica, and Malaysia provide training centers, population education, research, and evaluation as well as actual construction of clinics and mobile units. Because population planning touches sensitive areas of religion, caste, race, morality, and politics, the involved nation's political commitment to plan population growth is critical to the success of any program. PMID:12257161

  15. Language dynamics in finite populations.

    Science.gov (United States)

    Komarova, Natalia L; Nowak, Martin A

    2003-04-01

    Any mechanism of language acquisition can only learn a restricted set of grammars. The human brain contains a mechanism for language acquisition which can learn a restricted set of grammars. The theory of this restricted set is universal grammar (UG). UG has to be sufficiently specific to induce linguistic coherence in a population. This phenomenon is known as "coherence threshold". Previously, we have calculated the coherence threshold for deterministic dynamics and infinitely large populations. Here, we extend the framework to stochastic processes and finite populations. If there is selection for communicative function (selective language dynamics), then the analytic results for infinite populations are excellent approximations for finite populations; as expected, finite populations need a slightly higher accuracy of language acquisition to maintain coherence. If there is no selection for communicative function (neutral language dynamics), then linguistic coherence is only possible for finite populations.

  16. Stellar populations in star clusters

    CERN Document Server

    Li, Chengyuan; Deng, Licai

    2016-01-01

    Stellar populations contain the most important information about star clus- ter formation and evolution. Until several decades ago, star clusters were believed to be ideal laboratories for studies of simple stellar populations (SSPs). However, discoveries of multiple stellar populations in Galactic globular clusters have expanded our view on stellar populations in star clusters. They have simultaneously generated a number of controversies, particularly as to whether young star clusters may have the same origin as old globular clusters. In addition, extensive studies have revealed that the SSP scenario does not seem to hold for some intermediate-age and young star clusters either, thus making the origin of multiple stellar populations in star clusters even more complicated. Stellar population anomalies in numerous star clusters are well-documented, implying that the notion of star clusters as true SSPs faces serious challenges. In this review, we focus on stellar populations in massive clusters with different ...

  17. Population Health and Occupational Therapy.

    Science.gov (United States)

    Braveman, Brent

    2016-01-01

    Occupational therapy practitioners play an important role in improving the health of populations through the development of occupational therapy interventions at the population level and through advocacy to address occupational participation and the multiple determinants of health. This article defines and explores population health as a concept and describes the appropriateness of occupational therapy practice in population health. Support of population health practice as evidenced in the official documents of the American Occupational Therapy Association and the relevance of population health for occupational therapy as a profession are reviewed. Recommendations and directions for the future are included related to celebration of the achievements of occupational therapy practitioners in the area of population health, changes to the Occupational Therapy Practice Framework and educational accreditation standards, and the importance of supporting, recognizing, rewarding, and valuing occupational therapy practitioners who assume roles in which direct care is not their primary function.

  18. Anaerobic fungal populations

    International Nuclear Information System (INIS)

    The development of molecular techniques has greatly broadened our view of microbial diversity and enabled a more complete detection and description of microbial communities. The application of these techniques provides a simple means of following community changes, for example, Ishii et al. described transient and more stable inhabitants in another dynamic microbial system, compost. Our present knowledge of anaerobic gut fungal population diversity within the gastrointestinal tract is based upon isolation, cultivation and observations in vivo. It is likely that there are many species yet to be described, some of which may be non-culturable. We have observed a distinct difference in the ease of cultivation between the different genera, for example, Caecomyes isolates are especially difficult to isolate and maintain in vitro, a feature that is likely to result in the under representation of this genera in culture-based enumerations. The anaerobic gut fungi are the only known obligately anaerobic fungi. For the majority of their life cycles, they are found tightly associated with solid digesta in the rumen and/or hindgut. They produce potent fibrolytic enzymes and grow invasively on and into the plant material they are digesting making them important contributors to fibre digestion. This close association with intestinal digesta has made it difficult to accurately determine the amount of fungal biomass present in the rumen, with Orpin suggesting 8% contribution to the total microbial biomass, whereas Rezaeian et al. more recently gave a value of approximately 20%. It is clear that the rumen microbial complement is affected by dietary changes, and that the fungi are more important in digestion in the rumens of animals fed with high-fibre diets. It seems likely that the gut fungi play an important role within the rumen as primary colonizers of plant fibre, and so we are particularly interested in being able to measure the appearance and diversity of fungi on the plant

  19. European Population Substructure: Clustering of Northern and Southern Populations

    Science.gov (United States)

    Seldin, Michael F; Shigeta, Russell; Villoslada, Pablo; Selmi, Carlo; Tuomilehto, Jaakko; Silva, Gabriel; Belmont, John W; Klareskog, Lars; Gregersen, Peter K

    2006-01-01

    Using a genome-wide single nucleotide polymorphism (SNP) panel, we observed population structure in a diverse group of Europeans and European Americans. Under a variety of conditions and tests, there is a consistent and reproducible distinction between “northern” and “southern” European population groups: most individual participants with southern European ancestry (Italian, Spanish, Portuguese, and Greek) have >85% membership in the “southern” population; and most northern, western, eastern, and central Europeans have >90% in the “northern” population group. Ashkenazi Jewish as well as Sephardic Jewish origin also showed >85% membership in the “southern” population, consistent with a later Mediterranean origin of these ethnic groups. Based on this work, we have developed a core set of informative SNP markers that can control for this partition in European population structure in a variety of clinical and genetic studies. PMID:17044734

  20. A population genetics model of linkage disequilibrium in admixed populations

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Understanding linkage disequilibrium (LD) created in admixed population and the rate of decay in the disequilibrium over evolution is an important subject in population genetics theory and in disease gene mapping in human populations. The present study represents the theoretical investigation of effects of gene frequencies, levels of LD and admixture proportions of donor populations on the evolutionary dynamics of the LD of the admixed population. We examined the conditions under which the admixed population reached linkage equilibrium or the peak level of the LD. The study reveals the inappropriateness in approximating the dynamics of the LD generated by population admixture by the commonly used formula in literature. An appropriate equation for the dynamics is proposed. The distinct feature of the newly suggested formula is that the value of the nonlinear component of the LD remains constant in the first generation of the population evolution. Comparison between the predicted disequilibrium dynamics shows that the error will be caused by using the old formula, and thus resulting in a misguidance in using the evolutionary information of the admixed population in gene mapping.

  1. population in Slovakia

    Directory of Open Access Journals (Sweden)

    Dravecký Miroslav

    2015-06-01

    Full Text Available V rokoch 2011 – 2014 sa realizoval monitoring hniezdnej populácie orla krikľavého (Aquila pomarina v ôsmich chránených vtáčích územiach na Slovensku. U 149 hniezdnych párov z celkových 272 úspešných hniezdení počas 4 hniezdnych sezón vyletelo 277 mláďat. Priemerná reprodukčná úspešnosť predstavovala 0,51 juv./prítomný pár, 0,69 juv./hniezdiaci pár a 1,37 juv./100 km2. V uvedenom období bolo okolo hniezd orlov krikľavých ustanovených celkom 151 ochranných zón, ktoré zabezpečili ochranu 119 hniezdnych teritórií, čo predstavuje cca 17 % hniezdnej populácie orla krikľavého na Slovensku. Testovaním účinnosti ochranných zón sa zistilo, že v hniezdach s vyhlásenou ochrannou zónou je vyššia pravdepodobnosť úspešného odchovania mláďat v porovnaní s hniezdami bez takejto zóny. Pravdepodobnosť, že hniezdenie bude úspešné v hniezdach hniezdiacich párov bez ochrannej zóny bola 48.1% (95% confidence intervals (CIs: 37.4–59.0%, v hniezdach s ochrannou zónou 64.8% (95% CIs: 59.8–69.6%. Medzi 5 najčastejšie využívaných hniezdnych stromov na hniezdenie A. pomarina na Slovensku patrí Picea abies 61× (28,4%, Pinus sylvestris 45× (20,9%, Quercus sp. 36× (16,7%, Fagus sylvatica 25× (11,6% a Abies alba 18× (8,4%. Medzi zriedkavejšie druhy hniezdnych stromov patrí Larix decidua 12× (5,6% a Alnus glutinosa 3× (1,4%, ďalších 11 druhov hniezdnych stromov nedosiahli 1 %. Najvyšší počet hniezdnych stromov (n = 215, tj. 34 hniezd (15,8% sa nachádzal v intervale nadmorskej výšky 401 – 450 m a 29 hniezd (13,5% v intervale 351 – 400 m n. m. Ostatné výškové pásma boli pod hranicou 10%. 54% zistených hniezd (116 hniezd sa nachádza vo výškovom pásme 301 – 600 m n. m., 71 hniezd (33% v pásme 600 – 900 m n. m. Najnižšie situované hniezdo bolo v nadmorskej výške 150 m a najvyššie 950 m, priemer bol 595,01 m. Najvyšší počet hniezd (n = 209 bol na strome

  2. Wildlife Tunnel Enhances Population Viability

    Directory of Open Access Journals (Sweden)

    Michael McCarthy

    2009-12-01

    Full Text Available Roads and traffic are pervasive components of landscapes throughout the world: they cause wildlife mortality, disrupt animal movements, and increase the risk of extinction. Expensive engineering solutions, such as overpasses and tunnels, are increasingly being adopted to mitigate these effects. Although some species readily use such structures, their success in preventing population extinction remains unknown. Here, we use population viability modeling to assess the effectiveness of tunnels for the endangered Mountain Pygmy-possum (Burramys parvus in Australia. The underpasses reduced, but did not completely remove, the negative effects of a road. The expected minimum population size of a “reconnected” population remained 15% lower than that of a comparable “undivided” population. We propose that the extent to which the risk of extinction decreases should be adopted as a measure of effectiveness of mitigation measures and that the use of population modeling become routine in these evaluations.

  3. Effective Sizes for Subdivided Populations

    OpenAIRE

    Chesser, R. K.; Rhodes-Jr., O. E.; Sugg, D. W.; Schnabel, A.(Physikalisch Technische Bundesanstalt, Berlin, D-10587, Germany)

    1993-01-01

    Many derivations of effective population sizes have been suggested in the literature; however, few account for the breeding structure and none can readily be expanded to subdivided populations. Breeding structures influence gene correlations through their effects on the number of breeding individuals of each sex, the mean number of progeny per female, and the variance in the number of progeny produced by males and females. Additionally, hierarchical structuring in a population is determined b...

  4. Population Dynamics of Bacterial Persistence

    OpenAIRE

    Patra, Pintu; Klumpp, Stefan

    2013-01-01

    Persistence is a prime example of phenotypic heterogeneity, where a microbial population splits into two distinct subpopulations with different growth and survival properties as a result of reversible phenotype switching. Specifically, persister cells grow more slowly than normal cells under unstressed growth conditions, but survive longer under stress conditions such as the treatment with bactericidal antibiotics. We analyze the population dynamics of such a population for several typical ex...

  5. Regulation of wolf spider populations

    OpenAIRE

    Rickers, Silke

    2005-01-01

    Aim of this study was to identify major regulatory mechanisms for wolf spider populations. Field and laboratory experiments focussed on the importance of prey availability (autochthonous & allochthonous), food quality and habitat heterogeneity on performance of individual wolf spiders or whole populations and on intra- (cannibalism) and interspecific (intraguild predation) relationships in wolf spiders. Wolf spider populations on xeric grasslands near Darmstadt (Germany) are increased on graz...

  6. Fishermen, markets, and population diversity

    OpenAIRE

    Jardine, SL; Sanchirico, JN

    2015-01-01

    © 2015 Elsevier Inc. Fishing impacts biodiversity on multiple levels, potentially resulting in unintended feedbacks to the economic performance of the fishery over time. For example, targeting observable traits within a population can impact genetic diversity and targeting valuable species can impact biodiversity at the ecosystem level. The bioeconomic literature, however, has given little attention to the effect of fishing on population diversity, even though population diversity contributes...

  7. Population in the classic economics

    OpenAIRE

    Adnan Doğruyol

    2013-01-01

    Growth subject in economics is an important factor of development. Classic economics ecole indicates the population as main variable which tender of growth. On the other hand T. R. Malthus is known as economist who regards population as a problem and brings up it among the classical economists. However, Adam Smith is an intellectual who discussed population problem earlier on the classic economics theory. According to Adam Smith one of the main factors that realise the growth is labour. In ad...

  8. [Population control and environment protection].

    Science.gov (United States)

    Qu, G

    1982-01-29

    Although many factors cause environmental pollution and damage, the most important and basic factor is a rapidly increasing population. Therefore, a balanced development of population and environment is essential. The pressure a rapidly increasing populaton exerts on the environment has many aspects. The pressure of population on land resources results in increased land use and increased insecticide use due to increased insect tolerance leading to decreased productivity of cultivated land, increased desert formation, and decreased food supply. Population pressure on forest resources leads to land erosion; one of the major causes of the 1981 flood in Sichuan was attributed to excessive logging activities. Demand for fuels (firewood, straws, animal manures) by an increasing population leads to decrease in natural fertilizers, decreased food production, and energy shortage in rural areas. Population pressure on cities leads to air, water, noise and other environmental pollution as well as decrease in housing facilities and in green vegetation. Problems resulting from population pressures on industrial development include industrial and environmental pollution and unemployment. Population increases and accompanying industrial activities affect the weather which in turn affects the quality of agriculture, forests, and lakes. Thus, if unchecked, atmospheric carbon dioxide level would double by the middle of the next century, which would lead to increase in atmospheric temperature with disastrous consequences. Therefore, a well planned program for population control is essential for achieving decent quality of life. PMID:12338285

  9. [Population control and environment protection].

    Science.gov (United States)

    Qu, G

    1982-01-29

    Although many factors cause environmental pollution and damage, the most important and basic factor is a rapidly increasing population. Therefore, a balanced development of population and environment is essential. The pressure a rapidly increasing populaton exerts on the environment has many aspects. The pressure of population on land resources results in increased land use and increased insecticide use due to increased insect tolerance leading to decreased productivity of cultivated land, increased desert formation, and decreased food supply. Population pressure on forest resources leads to land erosion; one of the major causes of the 1981 flood in Sichuan was attributed to excessive logging activities. Demand for fuels (firewood, straws, animal manures) by an increasing population leads to decrease in natural fertilizers, decreased food production, and energy shortage in rural areas. Population pressure on cities leads to air, water, noise and other environmental pollution as well as decrease in housing facilities and in green vegetation. Problems resulting from population pressures on industrial development include industrial and environmental pollution and unemployment. Population increases and accompanying industrial activities affect the weather which in turn affects the quality of agriculture, forests, and lakes. Thus, if unchecked, atmospheric carbon dioxide level would double by the middle of the next century, which would lead to increase in atmospheric temperature with disastrous consequences. Therefore, a well planned program for population control is essential for achieving decent quality of life.

  10. Population dynamics and population control of Galium aparine L.

    NARCIS (Netherlands)

    Weide, van der R.Y.

    1993-01-01

    The population biology of Galium aparine L. needs to be better understood, in order to be able to rationalize decisions about the short- and long-term control of this weed species for different cropping practices.A population dynamics model was developed to simulate the basic processes of the life c

  11. Population Education: A Critical Population and Development Intervention.

    Science.gov (United States)

    United Nations Population Fund (UNFPA)

    1991-01-01

    This review and assessment of population education programs demonstrates that, although population education has made many contributions to the overall education process, its success requires continual revision and review of existing conceptualizations and content. Outlines and discusses other critical factors, pertinent issues, and guidelines for…

  12. Detection, Diversity, and Population Dynamics of Waterborne Phytophthora ramorum Populations.

    Science.gov (United States)

    Eyre, C A; Garbelotto, M

    2015-01-01

    Sudden oak death, the tree disease caused by Phytophthora ramorum, has significant environmental and economic impacts on natural forests on the U.S. west coast, plantations in the United Kingdom, and in the worldwide nursery trade. Stream baiting is vital for monitoring and early detection of the pathogen in high-risk areas and is performed routinely; however, little is known about the nature of water-borne P. ramorum populations. Two drainages in an infested California forest were monitored intensively using stream-baiting for 2 years between 2009 and 2011. Pathogen presence was determined both by isolation and polymerase chain reaction (PCR) from symptomatic bait leaves. Isolates were analyzed using simple sequence repeats to study population dynamics and genetic structure through time. Isolation was successful primarily only during spring conditions, while PCR extended the period of pathogen detection to most of the year. Water populations were extremely diverse, and changed between seasons and years. A few abundant genotypes dominated the water during conditions considered optimal for aerial populations, and matched those dominant in aerial populations. Temporal patterns of genotypic diversification and evenness were identical among aerial, soil, and water populations, indicating that all three substrates are part of the same epidemiological cycle, strongly influenced by rainfall and sporulation on leaves. However, there was structuring between substrates, likely arising due to reduced selection pressure in the water. Additionally, water populations showed wholesale mixing of genotypes without the evident spatial autocorrelation present in leaf and soil populations.

  13. Matrix population models from 20 studies of perennial plant populations

    Science.gov (United States)

    Ellis, Martha M.; Williams, Jennifer L.; Lesica, Peter; Bell, Timothy J.; Bierzychudek, Paulette; Bowles, Marlin; Crone, Elizabeth E.; Doak, Daniel F.; Ehrlen, Johan; Ellis-Adam, Albertine; McEachern, Kathryn; Ganesan, Rengaian; Latham, Penelope; Luijten, Sheila; Kaye, Thomas N.; Knight, Tiffany M.; Menges, Eric S.; Morris, William F.; den Nijs, Hans; Oostermeijer, Gerard; Quintana-Ascencio, Pedro F.; Shelly, J. Stephen; Stanley, Amanda; Thorpe, Andrea; Tamara, Ticktin; Valverde, Teresa; Weekley, Carl W.

    2012-01-01

    Demographic transition matrices are one of the most commonly applied population models for both basic and applied ecological research. The relatively simple framework of these models and simple, easily interpretable summary statistics they produce have prompted the wide use of these models across an exceptionally broad range of taxa. Here, we provide annual transition matrices and observed stage structures/population sizes for 20 perennial plant species which have been the focal species for long-term demographic monitoring. These data were assembled as part of the 'Testing Matrix Models' working group through the National Center for Ecological Analysis and Synthesis (NCEAS). In sum, these data represent 82 populations with >460 total population-years of data. It is our hope that making these data available will help promote and improve our ability to monitor and understand plant population dynamics.

  14. Matrix population models from 20 studies of perennial plant populations

    Science.gov (United States)

    Ellis, Martha M.; Williams, Jennifer L.; Lesica, Peter; Bell, Timothy J.; Bierzychudek, Paulette; Bowles, Marlin; Crone, Elizabeth E.; Doak, Daniel F.; Ehrlen, Johan; Ellis-Adam, Albertine; McEachern, Kathryn; Ganesan, Rengaian; Latham, Penelope; Luijten, Sheila; Kaye, Thomas N.; Knight, Tiffany M.; Menges, Eric S.; Morris, William F.; den Nijs, Hans; Oostermeijer, Gerard; Quintana-Ascencio, Pedro F.; Shelly, J. Stephen; Stanley, Amanda; Thorpe, Andrea; Tamara, Ticktin; Valverde, Teresa; Weekley, Carl W.

    2012-01-01

    Demographic transition matrices are one of the most commonly applied population models for both basic and applied ecological research. The relatively simple framework of these models and simple, easily interpretable summary statistics they produce have prompted the wide use of these models across an exceptionally broad range of taxa. Here, we provide annual transition matrices and observed stage structures/population sizes for 20 perennial plant species which have been the focal species for long-term demographic monitoring. These data were assembled as part of the "Testing Matrix Models" working group through the National Center for Ecological Analysis and Synthesis (NCEAS). In sum, these data represent 82 populations with >460 total population-years of data. It is our hope that making these data available will help promote and improve our ability to monitor and understand plant population dynamics.

  15. [Population policy: speeches and actions].

    Science.gov (United States)

    Soto Lopez, A

    1991-06-01

    Mexico's population policy was created almost 20 years ago in response to the need to regulate the country's population growth. Currently the policy stresses more balanced distribution of the population in accordance with realistic development possibilities. By 1986 it was recognized that population policy in Mexico had gone beyond mere control of fertility to encompass direct government intervention in more complex global problems. It was concluded that the possibility of achieving rational population distribution depended on balanced regional development. A strong family planning policy, efforts to integrate demographic programs into general development plans, employment policies, and measures to encourage harmonious spatial distribution were viewed as necessary, but it was also felt that greater speed was required and that the population policy should play a larger role in the development strategy. The National Population Program for 1989-94 has the objectives of promoting the integration of demographic objectives into economic and social planning and promoting a decline in the rate of population growth from 1.8% in 1995 to 1.5% in 2000 through fertility decline. It seeks a more rational population distribution in which the weight of large metropolitan zones would be reduced and growth of intermediate and small cities promoted. It seeks to encourage greater participation by women in the nation's life, and to contribute to integrated development and elevation in the living standards of indigenous groups. In presentation of the National Population Program it was noted that the economic crisis of the 1980s had reversed some previous demographic achievements. greater efforts are necessary to involve the rural and indigenous groups. In presentation of the National Population Program it was noted that the economic crisis of the 1980s had reversed some previous demographic achievements. Greater efforts are necessary to involve the rural and indigenous populations

  16. Stochastic delocalization of finite populations

    Science.gov (United States)

    Geyrhofer, Lukas; Hallatschek, Oskar

    2013-01-01

    The localization of populations of replicating bacteria, viruses or autocatalytic chemicals arises in various contexts, such as ecology, evolution, medicine or chemistry. Several deterministic mathematical models have been used to characterize the conditions under which localized states can form, and how they break down due to convective driving forces. It has been repeatedly found that populations remain localized unless the bias exceeds a critical threshold value, and that close to the transition the population is characterized by a diverging length scale. These results, however, have been obtained upon ignoring number fluctuations (‘genetic drift’), which are inevitable given the discreteness of the replicating entities. Here, we study the localization/delocalization of a finite population in the presence of genetic drift. The population is modeled by a linear chain of subpopulations, or demes, which exchange migrants at a constant rate. Individuals in one particular deme, called ‘oasis’, receive a growth rate benefit, and the total population is regulated to have constant size N. In this ecological setting, we find that any finite population delocalizes on sufficiently long time scales. Depending on parameters, however, populations may remain localized for a very long time. The typical waiting time to delocalization increases exponentially with both population size and distance to the critical wind speed of the deterministic approximation. We augment these simulation results by a mathematical analysis that treats the reproduction and migration of individuals as branching random walks subject to global constraints. For a particular constraint, different from a fixed population size constraint, this model yields a solvable first moment equation. We find that this solvable model approximates very well the fixed population size model for large populations, but starts to deviate as population sizes are small. Nevertheless, the qualitative behavior of the

  17. [Population science serves human happiness].

    Science.gov (United States)

    Qian, X

    1983-03-29

    4 areas are covered in this speech delivered on January 10, 1983. 1) Looking back on China's post-Liberation population problems: as early as the 1950s, the Party and scholars such as Ma Yinchu recognized the need to control population growth. For instance, a 1952 directive instructed the Public Health Bureau to encourage the use of condoms and diaphrams. When Ma Yinchu's studies showing alarming population increases were made known to Mao Zedong and published in the People's Daily in 1957, the "new population theory" was formed, which advocated population control. But before this idea gained currency, Ma suffered criticism in 1958 and population studies was virtually halted. Between 1958-61, as China entered difficult times, the birthrate declined. By 1962 the rate increased, leading the Central Committee of the Chinese Communist Party to issue a directive to control population. Again in 1971 the Central Government set population goals and incorporated population policies into national economic planning. When the wrongs of the Cultural Revolution were redressed, Ma Yinchu regained favor and demography entered a new era. 2) The responsibility of demographic studies: one of the most important tasks of demography is to solve the problem of confining the birthrate to 16-17/1000 annually, so that by 2000 the total population would be 1,200,000,000. This can only be done by advocating 1 child per couple, closely con trolling a 2nd birth and discouraging all 3rd births. 3) The contents of demographic studies: both immediate and future problems must be addressed. Areas of study can include sex ratio, marriage, family, population and land distribution, fertility, or an aging society. 4) Science research must embody a scientific attitude: it is best to follow the example set by Ma Yinchu, whose work was based on actual investigations in the field. Any development and production of scientific theory must stem from practical experience. PMID:12313013

  18. Perfect Simulation From Nonneutral Population Genetic Models: Variable Population Size and Population Subdivision.

    OpenAIRE

    Fearnhead, Paul

    2006-01-01

    We show how the idea of monotone coupling from the past can produce simple algorithms for simulating samples at a nonneutral locus under a range of demographic models. We specifically consider a biallelic locus and either a general variable population size mode or a general migration model for population subdivision. We investigate the effect of demography on the efficacy of selection and the effect of selection on genetic divergence between populations.

  19. Perturbation Theory for Population Dynamics

    CERN Document Server

    Fernandez, Francisco M

    2007-01-01

    We prove that a recently proposed homotopy perturbation method for the treatment of population dynamics is just the Taylor expansion of the population variables about initial time. Our results show that this perturbation method fails to provide the global features of the ecosystem dynamics.

  20. Kingman and mathematical population genetics

    OpenAIRE

    Ewens, Warren J.; Watterson, Geoffrey A.

    2010-01-01

    Mathematical population genetics is only one of Kingman's many research interests. Nevertheless, his contribution to this field has been crucial, and moved it in several important new directions. Here we outline some aspects of his work which have had a major influence on population genetics theory.

  1. Food for the ageing population

    NARCIS (Netherlands)

    Raats, M.M.; Groot, de C.P.G.M.; Staveren, van W.A.

    2008-01-01

    The world’s ageing population is increasing and food professionals will have to address the needs of older generations more closely in the future. This unique volume reviews the characteristics of the ageing population as food consumers, the role of nutrition in healthy ageing and the design of food

  2. Estimated population near uranium tailings

    Energy Technology Data Exchange (ETDEWEB)

    Bloomster, C.H.; Brown, D.R.; Bruno, G.A.; Craig, S.N.; Dirks, J.A.; Griffin, E.A.; Reis, J.W.; Young, J.K.

    1984-01-01

    Population studies, which took place during the months of April, May, and June 1983, were performed for 27 active and 25 inactive mill sites. For each mill site, a table showing population by radius (1/2, 1, 2, 3, 4, and 5 km) in 16 compass directions was generated. 22 references, 6 tables.

  3. Population and policy in Finland.

    Science.gov (United States)

    Hulkko, J

    1989-03-01

    Finland, with a population of 4.9 million, currently has an overall fertility rate of 1.6. There is a small population growth, but this is due to a large reproductive age group, return migration of Finns from Sweden, and a decrease in mortality that has increased the proportion of old people in the population. The state has no official population policy. A recommendation of the Finnish Committee on the World Population Year 1974 that the government establish an agency for population policy has not been adopted. The coalition government now in power has a program, however, aimed at influencing population growth. The program includes proposals to reduce work hours for parents with small children, increase the age limit for participation in the child allowance system, and increase the number of municipal day care facilities. Concerning regional policy, the government wants a balanced development of the country's different regions. Subsidiary industries of agriculture and forestry are being encouraged to preserve population levels in sparse areas. Finland also supports a health policy emphasizing preventive and non-institutional aspects of health care, with targets of life expectancy set at 82 years for women and 75 years for men by the year 2000. PMID:12222205

  4. Population in the classic economics

    Directory of Open Access Journals (Sweden)

    Adnan Doğruyol

    2013-02-01

    Full Text Available Growth subject in economics is an important factor of development. Classic economics ecole indicates the population as main variable which tender of growth. On the other hand T. R. Malthus is known as economist who regards population as a problem and brings up it among the classical economists. However, Adam Smith is an intellectual who discussed population problem earlier on the classic economics theory. According to Adam Smith one of the main factors that realise the growth is labour. In addition to population made it established. The aim of this study is analyzing the mental relationship between Malthus whose name has been identified with relation between population-growth and Smith who discussed this subject first time but put it off on process of theorisation.

  5. Population control in symbiotic corals

    Energy Technology Data Exchange (ETDEWEB)

    Falkowski, P.G. (Brookhaven National Lab., Upton, NY (United States)); Dubinsky, Z. (Bar Ilan Univ., Ramat Gan (Israel)); Muscatine, L. (Univ. of California, Los Angeles, CA (United States)); McCloskey, L. (Walla Walla College, College Place, WA (United States))

    1993-10-01

    Stability in symbiotic association requires control of population growth between symbionts. The population density of zooxanthellae per unit surface area of most symbiotic corals is remarkably consistant. How is the population density of zooxanthellae maintained and what happens to the symbiotic association if the balance between algae and host is perturbed. The answers to these question, examined in this paper, provide a framework for understanding how the size of the component populations is controlled in symbiotic associations. The topic areas covered include the following: carbon economy in a symbiotic coral; effects of nutrient enrichment; the chemostat model of population control; the effects of exposure to ammonium levels. Ammonium ions and organic materials are the factors which maintain the density of zooxanthellae. 32 refs., 5 figs.

  6. Population problems and population research in a market economy.

    Science.gov (United States)

    Tian, X

    1994-01-01

    A market driven economy has many effects on population growth. The laws of social production were explicated by Marx and Engels, and Comrade Deng Xiaoping presents his views on China's socialist market economy and population problems in this article. Modern market economies have changed greatly over time. Before the 1960s, the focus of the interaction between population and economic change was in macro control. Since the 1960s, the focus shifted to micro control. Theories on maximum growth and neomodern population theory provide only a few useful elements. Cost-benefit analysis of child production functions, despite limitations, has universal appeal. Western theories with sound scientific evidence and Marxist theories should be examined and integrated within the Chinese experience. Two areas of concern in China are the spatial imbalance between population and economic development and an appropriate time period for any research activity. Scientific research in China will be advanced by careful integration of theory and practice, careful study of the Chinese experience, in-depth analysis, and bold, practical approaches which incorporate existing research results from the West. There are three dominant views of economic reforms. 1) Economic development plans should include a market economy. 2) Chinese population control would depend upon administrative means rather than market forces. 3) There are indirect ways in which the market affects population production. The last position is favored. The conclusions are made that family planning has been and continues to be a driving force in declining birth rates and that a focus on government population control does not discount the importance of the influence of economic factors on changes in the birth rate. Market forces are beginning to show their impact on people's choice in reproduction, and the impact is increasing. Reforms must be made appropriate to both the position and the negative influence of the market economy on

  7. BIRTH AND DEATH RATES, NATIONAL POPULATION FORECAST AND POPULATION POLICIES

    Directory of Open Access Journals (Sweden)

    K Merat

    1971-07-01

    Full Text Available This study is analyses of national population estimates and aims for the next 20 to 50 years. Calculations are based on the population of 32 million in 1973 with the relative growth rate of 32 in 1000 and death rate of 16 in 1000.Considering various aims, reduction in the growth rate, birth rate and populations in the future years have been calculated. The results showed the need for extensive efforts in reduction of fertility in order to reach zero growth rate in 50 years (2023.

  8. Tibet's population: past and present.

    Science.gov (United States)

    Tu, D

    1997-08-01

    This article describes trends in population growth in Tibet during the Yuan Dynasty (1260-1287), the Qing Dynasty (1734-36), and during decennial periods after 1952, until 1994. Tibet was conquered by the Mongols who founded the Yuan Dynasty in the 13th century. During 1260-87, 3 enumerations revealed a total population of about 559,962 Tibetans, of whom 70,000 were lamas. Enumeration during 1734-36, revealed a total population of 941,151 Tibetans and 138,617 households. Tibet's population increased to about 1 million in 1951, an addition of 60,000 persons over 210 years. During 1952-59, the rate of population growth was fairly low at 0.94%. The total increase was 78,000 persons, or 11,000/year. Population increased from 1.15 million to about 1.23 million during 1952-59. The Dalai Lama went into exile with about 74,000 Tibetans in March 1959. Population during 1960-69 increased from 1.23 million to 1.48 million. The annual growth rate was 1.89%. Population increased by 252,500 persons, or 25.300/year. Reforms were carried out during this period. The region shifted from feudalism to socialism. Tibetans obtained free medical care and access to land. The birth rate was 25/1000, and the death rate was 10/1000. During 1970-79, both economic and population growth increased. Population increased from 1.48 million to 1.83 million, or a rate of annual growth of 2.14%. Population during this period increased by 348,500 persons, or 34,900/year. This was the fastest period of population growth. During 1980-89, the total fertility rate was maintained at around 4 children/woman, and family planning was implemented in urban areas. The annual rate of growth was 1.85%. Population increased by 367,000 persons, or 36,700/year. During 1990-94, the annual growth rate was 1.76 with a total increase of 159,000 persons, or 39,800/year.

  9. Can human populations be stabilized?

    Science.gov (United States)

    Warren, Stephen G.

    2015-02-01

    Historical examples of demographic change, in China, Italy, Nigeria, Utah, Easter Island, and elsewhere, together with simple mathematics and biological principles, show that stabilizing world population before it is limited by food supply will be more difficult than is generally appreciated. United Nations population projections are wrong because they assume, in spite of the absence of necessary feedbacks, that all nations will converge rapidly to replacement-level fertility and thereafter remain at that level. Education of women and provision of contraceptives have caused dramatic reductions in fertility, but many groups, including some that are well-educated, maintain high fertility. Small groups with persistent high fertility can grow to supplant low-fertility groups, resulting in continued growth of the total population. The global average fertility rate could rise even if each country's fertility rate is falling. In some low-fertility European countries where deaths exceed births, the population continues to grow because of immigration. Producing more than two offspring is normal for all animal species with stable populations because their populations are limited by resources or predation rather than birth control. It may therefore be appropriate to view the growth of human population as the result not of excess fertility but rather of excess food.

  10. Soviet Marxism and population policy.

    Science.gov (United States)

    Vonfrank, A

    1984-01-01

    American demographers have maintained that Marxism, notably Soviet Marxism, is consistently pronatalist. The Soviet view is said to be that population growth is not a problem and that birth control policies in either developed or developing societies are to be rejected; the "correct" (i.e., socialist) socioeconomic structure is the true solution to alleged population problems. Such representations of Soviet thought greatly oversimplify the Soviet position as well as fail to discern the changes in Soviet thought that have been occurring. Since the 1960s Soviet writers have increasingly acknowledged that population growth is, to a considerable degree, independent of the economic base of society and that conscious population policies may be needed to either increase or decrease the rate of population growth. Even socialist societies can have population problems. And where population growth is too rapid, as in the developing countries, policies to slow such growth are needed because of the threat to economic development. However, the Soviets continue to stress that birth control policies must go hand-in-hand with social and economic development policies if they are to be effective. PMID:12339937

  11. Modern population trends in Bangladesh.

    Science.gov (United States)

    Abul-basher, M M

    1985-01-01

    Population growth trends in Bangladesh in the 1871-1981 period were analyzed, with emphasis on fertility and mortality differentials, to provide a basis for population planning. Following proclamation of British Imperial Rule in 1857, mortality rates in Bangladesh began to decline as a result of preventive measures against natural disasters such as draught and famine, but the fertility rate remained unaltered. The demographic pattern was unstable over time, reflecting the impact of the influenza epidemic of 1918-19, war, migration, and economic development. Population growth accelerated greatly during the 1961-74 period, when industrialization emerged and job opportunities were created in the urban centers. Economic hardship, food shortages, and the introduction of family planning curbed urban growth drastically and total growth to some extent in 1974-81. On the average, growth has been higher in the Dhaka and Chittagong Divisions of Bangladesh than in the Khulna and Rajshahi Divisions. Differences in population growth among the regions are attributable largely to internal and external migration. The regression polynomial model best fits past population trends in Bangladesh and can reproduce the observed population by 99.60%. This polynomial is most suitable for graduation and prediction of population trends. PMID:12280834

  12. Population and Australian development assistance.

    Science.gov (United States)

    Jones, R

    1992-07-01

    Australia's position on international population issues is consistent with the major international statements on population: the World Population Plan of Action (1974), the Mexico City Declaration (1984), and the Amsterdam Declaration (1989). Australia's policy emphasizes the importance of population policies as an integral part of social, economic, and cultural development aimed at improving the quality of life of the people. Factors that would promote smaller families include improving economic opportunities, old-age security, education and health (particularly for women), as well as improving the accessibility and quality of family planning services. The quality of care approach is directly complementary to the Australian International Development Assistance Bureau (AIDAB)'s Women-In-Development Policy and its Health Policy, which stresses the theme of Women And Their Children's Health (WATCH). Australia's support for population programs and activities has increased considerably over the last few years. Total assistance for the year 1990/91 was around $7 million out of a total aid program of $1216 million. In recent years AIDAB has funded family planning activities or health projects with family planning components in a number of countries in the Asia-Pacific region. In the South Pacific region AIDAB has funded a reproductive health video project taking into consideration the cultural sensitivities and customs of the peoples of the region. AIDAB has supported a UN Population Fund project in Thailand that aims to strengthen the capacity of the National Statistical Office to collect population data. The US currently accounts for around 40% of all population-related development assistance to improve the health of women and children through family planning. The other major donors are Japan, the Scandinavian countries, and the Netherlands. Funding for population has been a relatively low percentage of overall development assistance budgets in OECD countries. In the

  13. Food production and population growth.

    Science.gov (United States)

    Pereira, H C

    1993-07-01

    Governments have frequently ignored the issue of population consumption exceeding the rates of renewal of natural resources. At the UN Conference on the Environment and Development in Rio de Janeiro, the issue of population growth was ignored in the agenda and action plan. In 1974, the UN World Population Conference suggested population stability would be possible if standards of living were raised. Industrialized nations spent half a century of active interference with the stability of global populations and failed to slow growth. 27 countries, mainly in tropical and subtropical zones, have an average cereal yield of under 1 ton per hectare, when improved seed and basic minimum fertilizer could yield 2 tons per hectare. Efforts to increase yields by the Consultative Group for International Agricultural research in 13 international centers resulted in global annual increases of about 50 million tons of grain (wheat and rice). Rainfed agriculture did not benefit as much because of climatic conditions. Where varieties of triticale, sorghum, millet, groundnuts, chick peas, cowpeas, beans, and cassava have helped increase food production, population growth has outstripped the gains. Agricultural fertilizers have been unfairly blamed for soil nutrient losses. Because of the age structure of population, the expected population growth can only be addressed through development of higher yields, new strains resistant to disease, and fertilizers. Slow release phosphates for tropical soils are needed. Shortages of domestic fuel divert much needed farmyard manure and composted crop residues. About 400 million tons of dung are thus wasted annually; food grain harvests are thus reduced by 14 million tons. About 50% of the 1133 million poorest people will live in Asia and another 25% will live in Sub-Saharan Africa, living on a total degraded area of 1219 million hectares. Imbalance between food supply and population need to be addressed on an effective international scale.

  14. Simulation of population growth and structure of the population

    Science.gov (United States)

    Maksymowicz, A. Z.

    2002-08-01

    A computer study of population growth and biological ageing in the Penna model is presented. The stress is put on the analysis of the age structure and the distribution of 'bad' mutations m in the population. Results of computer simulation are compared with the simplest logistic model approach which ignores genetic contribution to the life game and accounts only for death due to limited environmental capacity, the Verhulst factor. The Penna model accounts also for genetic load and results of the simulation show that the final population essentially consists of the fittest individuals, as is expected. A more detailed analysis of the genome structure Δ( m) discloses significant marks of the history. The main conclusions are: (a) there is a clear correlation between population n, age a and the number m of bad mutations and (b) there is no correlation between particular configurations Δ( m) of genomes of the same m and the fraction of the population of this characteristics Δ( m). A typical run takes a couple of hours on an HP EXEMPLAR machine, and for a population of about n=10 6.

  15. Population Issues. Resources in Technology.

    Science.gov (United States)

    Technology Teacher, 1991

    1991-01-01

    Presents information about the problems caused by increasing population. Discusses the environmental impact and the ways that technology can be used to solve problems of overpopulation. Includes possible student outcomes and a student quiz. (JOW)

  16. Punctuated evolution of population genomics

    OpenAIRE

    Reuveni, Eli

    2012-01-01

    In this thesis I apply population genetics methods and genotype-phenotype mapping to show that evolution has more discrete rather than linear pace and that this finding may reconcile between two evolution theories (punctuated equilibrium and phyletic gradualism)

  17. Anomalous Growth of Aging Populations

    Science.gov (United States)

    Grebenkov, Denis S.

    2016-04-01

    We consider a discrete-time population dynamics with age-dependent structure. At every time step, one of the alive individuals from the population is chosen randomly and removed with probability q_k depending on its age, whereas a new individual of age 1 is born with probability r. The model can also describe a single queue in which the service order is random while the service efficiency depends on a customer's "age" in the queue. We propose a mean field approximation to investigate the long-time asymptotic behavior of the mean population size. The age dependence is shown to lead to anomalous power-law growth of the population at the critical regime. The scaling exponent is determined by the asymptotic behavior of the probabilities q_k at large k. The mean field approximation is validated by Monte Carlo simulations.

  18. National workshop on population education.

    Science.gov (United States)

    Haq, M

    1979-01-01

    The First National Workshop on Population Education was held from 16 to 18 November 1978, involving principals and instructors in extension education of all the eight agricultural extension training institutes, regional directors of agriculture, some district extension officers and representatives from voluntary agencies involved in population education. The object of the Workshop was to discuss and modify the materials prepared for the introduction of the concept of population education in agricultural training institutes. Some materials were also adopted for training purposes of village extension agents. The World Bank project of the Ministry of Agriculture is responsible for introducing in Bangladesh the concept of population education to pre-service, village-level extension workers in the various agricultural extension institutes, and the first project to recruit female extension workers for service in rural areas. PMID:12309487

  19. The Veteran Population Projection 2014

    Data.gov (United States)

    Department of Veterans Affairs — VetPop2014 is an actuarial projection model developed by the Office of the Actuary (OACT) for Veteran population projection from Fiscal Year FY2014 to FY2043. Using...

  20. Effective sizes for subdivided populations.

    Science.gov (United States)

    Chesser, R K; Rhodes, O E; Sugg, D W; Schnabel, A

    1993-12-01

    Many derivations of effective population sizes have been suggested in the literature; however, few account for the breeding structure and none can readily be expanded to subdivided populations. Breeding structures influence gene correlations through their effects on the number of breeding individuals of each sex, the mean number of progeny per female, and the variance in the number of progeny produced by males and females. Additionally, hierarchical structuring in a population is determined by the number of breeding groups and the migration rates of males and females among such groups. This study derives analytical solutions for effective sizes that can be applied to subdivided populations. Parameters that encapsulate breeding structure and subdivision are utilized to derive the traditional inbreeding and variance effective sizes. Also, it is shown that effective sizes can be determined for any hierarchical level of population structure for which gene correlations can accrue. Derivations of effective sizes for the accumulation of gene correlations within breeding groups (coancestral effective size) and among breeding groups (intergroup effective size) are given. The results converge to traditional, single population measures when similar assumptions are applied. In particular, inbreeding and intergroup effective sizes are shown to be special cases of the coancestral effective size, and intergroup and variance effective sizes will be equal if the population census remains constant. Instantaneous solutions for effective sizes, at any time after gene correlation begins to accrue, are given in terms of traditional F statistics or transition equations. All effective sizes are shown to converge upon a common asymptotic value when breeding tactics and migration rates are constant. The asymptotic effective size can be expressed in terms of the fixation indices and the number of breeding groups; however, the rate of approach to the asymptote is dependent upon dispersal

  1. Population size and environmental quality

    OpenAIRE

    Till Requate; Mark B. Cronshaw

    1997-01-01

    This paper presents a simple general equilibrium analysis of first best allocations in an economy where a consumption good is produced using labor. Production results in pollution, which is a public bad. Pollution abatement can be achieved either by restricting production or by using additional labor. We consider how the first best allocation and Pigouvian tax vary with population size. Consumers are unambiguously worse off when the population is larger, but not necessarily due to increased p...

  2. Wildlife Tunnel Enhances Population Viability

    OpenAIRE

    Michael McCarthy; Dean Heinze; Rodney van der Ree; Ian Mansergh

    2009-01-01

    Roads and traffic are pervasive components of landscapes throughout the world: they cause wildlife mortality, disrupt animal movements, and increase the risk of extinction. Expensive engineering solutions, such as overpasses and tunnels, are increasingly being adopted to mitigate these effects. Although some species readily use such structures, their success in preventing population extinction remains unknown. Here, we use population viability modeling to assess the effectiveness of tunnels f...

  3. Eel population and solution model

    OpenAIRE

    Chen, Liangming; Chen, Xinyu; Chen, Yu; Fang, Ping; Huang, Yuyu; Li, Haiyan; Liu, Mingyan; Wang, Cong

    2006-01-01

    Almost two decades before, eel population had not waved quite hugely, but in this twenty years, it is changed. Eel population decreases very obviously on account of five main reasons—pollution, barriers, the change of ocean currents, overfishing, diseases. Base on this phenomena, though our research, we would like to suggest two solution for changing the decline. In short-term, aquaculture should be utilized widely; on the other hand, re-stocking is a quiet nice method for long-term.

  4. Introduction. Population and the environment.

    Science.gov (United States)

    Clarke, J; Zaba, B

    1992-01-01

    The complexity of the interrelationships between population growth and environmental concerns is often obscured when the global picture is presented. The variety and complexity of population-environment associations varies with spatial aggregation; analysis is needed at all levels. Of the many organizations involved in researching and discussing these associations, the International Social Science Council established a working committee on population and the environment, which held a symposium in January 1991. 9 papers were the topic of discussions and are summarized in this article. Attention was focused on pollution emissions and population growth by the environmental scientist Paul Harrison. The increased demand for water was discussed as it related to rapid urbanization and changes in agricultural production and industrial development policies. David Noin's paper was on the increased occurrence of natural disasters and mortality, i.e., cyclones and floods. The population densities surrounding areas of natural disasters excluding droughts have increased and contributed to greater impacts. Alina Potrykowska and Roger Bivend provided information on the trends and spatial patterns of mortality in Poland. Mortality increases have appeared during the course of industrialization. Data for Poland on environmental variables such as dust and gas emissions, volume of untreated waste, and hazardous waste are available for 49 voivodships. The most polluted areas show a statistically significant relationships with high morality. Ken Wilson presented his views on the contradiction that African famines did not cause population decline. The possible interpretations are misinterpretation of data, inappropriate scales of measurement, and a misspecification that social, economic, and political changes will improve the population environment links. Matthew Lockwood presented his findings on northern Nigeria that migration is an important cause of high density population, and that

  5. Genetic Structure of Chimpanzee Populations

    OpenAIRE

    Celine Becquet; Nick Patterson; Anne C Stone; Molly Przeworski; David Reich

    2007-01-01

    Author Summary Common chimpanzees have been traditionally classified into three populations: western, central, and eastern. While the morphological or behavioral differences are very small, genetic studies of mitochondrial DNA and the Y chromosome have supported the geography-based designations. To obtain a crisp picture of chimpanzee population structure, we gather far more data than previously available: 310 microsatellite markers genotyped in 78 common chimpanzees and six bonobos, allowing...

  6. Population Aging and Inventive Activity

    OpenAIRE

    Irmen, Andreas; Litina, Anastasia

    2016-01-01

    This research empirically establishes and theoretically motivates the hypothesis that population aging has a hump-shaped effect on inventive activity. We estimate this hump-shaped relationship in a panel of 33 OECD countries over the period 1960-2012. The increasing part of the hump captures the awareness that population aging requires inventive activity to guarantee current and future standards of living. The decreasing part reflects the tendency of aging societies to lose dynamism and the w...

  7. Canada's population: growth and dualism.

    Science.gov (United States)

    Beaujot, R P

    1978-04-01

    In Canada the current 1.3% population growth rate is causing some concern. Those concerned argue that such a rate of growth in combination with high levels of consumption could jeopardize the country's resource base and its comfortable style of living. Many Canadians are questioning high levels of immigration, for now that the fertility level is below replacement level, net immigration contributes substantially to population growth (over 1/3 in 1976). The growing proportion of non-Europeans among recent immigrants is causing resentment, and, in a tight job market, immigrants are regarded as threats to the World War 2 baby boom cohort who are now at working ages. The baby boom generation also puts stress on housing and health services, and it will increase the need for pension checks as it ages. Although French fertility is no longer high and immigration is no longer dominated by the British, the French group's 200-year struggle to preserve its identity continues on in the current effort of the Quebec government to enforce the use of French language by law within that province. Geography and climate dictate another demographic fact that divides the country and pervades its history. In addition to intense regionalism, uneven population distribution is responsible for 2 other concerns: the rapid growth of several already large cities and depopulation of many small communities. Focus in this discussion is on Canada's population growth in the past and as projected for the future, historical and current fertility, mortality and immigration trends, the search for a new immigration policy, the impact of the baby boom generation on the population's age structure and the problems this creates, and recent shifts in population distribution and in the country's ethnic and linguistic makeup. The population policy proposals evolved thus far involve to a great extent the use of immigration as a lever for achieving given population objectives.

  8. Environmental pollution and population policies.

    Science.gov (United States)

    1980-04-01

    There is a growing recognition in Malaysia of the interrelationship between population growth, population policies, development policies, and environmental pollution. In Malaysia, with a current population of 13,250,000 and an annual growth rate of 2.4%, economic development is leading to large scale deforestation which in turn is altering climatic conditions, reducing water supplies, and increasing erosion. According to estimates 750,000 acres of jungle were cleared in the last 10 years. Industrial wastes and domestic sewage discharged into rivers and lakes is endangering marine life and padilands. This is a serious problem, since 70% of the Malaysian population derives the bulk of their protein intake from marine life. Noise and carbon monoxide pollution in urban areas is increasing due to the 15% annual increase in the number of vehicles in the country. These dangers need to be taken into account as continuing efforts are made to increase industrialization in order to provide jobs for the 350,000 unemployed and underemployed youth in the country. Fortunately, government officials in Malaysia are giving consideration to energy, water and oil conservation in formulating development plans and are becoming increasingly aware that population growth and population policies have a direct impact on development planning and environmental pollution. PMID:12262045

  9. Population growth and economic growth.

    Science.gov (United States)

    Narayana, D L

    1984-01-01

    This discussion of the issues relating to the problem posed by population explosion in the developing countries and economic growth in the contemporary world covers the following: predictions of economic and social trends; the Malthusian theory of population; the classical or stationary theory of population; the medical triage model; ecological disaster; the Global 2000 study; the limits to growth; critiques of the Limits to Growth model; nonrenewable resources; food and agriculture; population explosion and stabilization; space and ocean colonization; and the limits perspective. The Limits to Growth model, a general equilibrium anti-growth model, is the gloomiest economic model ever constructed. None of the doomsday models, the Malthusian theory, the classical stationary state, the neo-Malthusian medical triage model, the Global 2000 study, are so far reaching in their consequences. The course of events that followed the publication of the "Limits to Growth" in 1972 in the form of 2 oil shocks, food shock, pollution shock, and price shock seemed to bear out formally the gloomy predictions of the thesis with a remarkable speed. The 12 years of economic experience and the knowledge of resource trends postulate that even if the economic pressures visualized by the model are at work they are neither far reaching nor so drastic. Appropriate action can solve them. There are several limitations to the Limits to Growth model. The central theme of the model, which is overshoot and collapse, is unlikely to be the course of events. The model is too aggregative to be realistic. It exaggerates the ecological disaster arising out of the exponential growth of population and industry. The gross underestimation of renewable resources is a basic flaw of the model. The most critical weakness of the model is its gross underestimation of the historical trend of technological progress and the technological possiblities within industry and agriculture. The model does correctly emphasize

  10. Population growth and economic growth.

    Science.gov (United States)

    Narayana, D L

    1984-01-01

    This discussion of the issues relating to the problem posed by population explosion in the developing countries and economic growth in the contemporary world covers the following: predictions of economic and social trends; the Malthusian theory of population; the classical or stationary theory of population; the medical triage model; ecological disaster; the Global 2000 study; the limits to growth; critiques of the Limits to Growth model; nonrenewable resources; food and agriculture; population explosion and stabilization; space and ocean colonization; and the limits perspective. The Limits to Growth model, a general equilibrium anti-growth model, is the gloomiest economic model ever constructed. None of the doomsday models, the Malthusian theory, the classical stationary state, the neo-Malthusian medical triage model, the Global 2000 study, are so far reaching in their consequences. The course of events that followed the publication of the "Limits to Growth" in 1972 in the form of 2 oil shocks, food shock, pollution shock, and price shock seemed to bear out formally the gloomy predictions of the thesis with a remarkable speed. The 12 years of economic experience and the knowledge of resource trends postulate that even if the economic pressures visualized by the model are at work they are neither far reaching nor so drastic. Appropriate action can solve them. There are several limitations to the Limits to Growth model. The central theme of the model, which is overshoot and collapse, is unlikely to be the course of events. The model is too aggregative to be realistic. It exaggerates the ecological disaster arising out of the exponential growth of population and industry. The gross underestimation of renewable resources is a basic flaw of the model. The most critical weakness of the model is its gross underestimation of the historical trend of technological progress and the technological possiblities within industry and agriculture. The model does correctly emphasize

  11. Population dynamics in variable environments

    CERN Document Server

    Tuljapurkar, Shripad

    1990-01-01

    Demography relates observable facts about individuals to the dynamics of populations. If the dynamics are linear and do not change over time, the classical theory of Lotka (1907) and Leslie (1945) is the central tool of demography. This book addresses the situation when the assumption of constancy is dropped. In many practical situations, a population will display unpredictable variation over time in its vital rates, which must then be described in statistical terms. Most of this book is concerned with the theory of populations which are subject to random temporal changes in their vital rates, although other kinds of variation (e. g. , cyclical) are also dealt with. The central questions are: how does temporal variation work its way into a population's future, and how does it affect our interpretation of a population's past. The results here are directed at demographers of humans and at popula­ tion biologists. The uneven mathematical level is dictated by the material, but the book should be accessible to re...

  12. Laplacian eigenfunctions learn population structure.

    Directory of Open Access Journals (Sweden)

    Jun Zhang

    Full Text Available Principal components analysis has been used for decades to summarize genetic variation across geographic regions and to infer population migration history. More recently, with the advent of genome-wide association studies of complex traits, it has become a commonly-used tool for detection and correction of confounding due to population structure. However, principal components are generally sensitive to outliers. Recently there has also been concern about its interpretation. Motivated from geometric learning, we describe a method based on spectral graph theory. Regarding each study subject as a node with suitably defined weights for its edges to close neighbors, one can form a weighted graph. We suggest using the spectrum of the associated graph Laplacian operator, namely, Laplacian eigenfunctions, to infer population structure. In simulations and real data on a ring species of birds, Laplacian eigenfunctions reveal more meaningful and less noisy structure of the underlying population, compared with principal components. The proposed approach is simple and computationally fast. It is expected to become a promising and basic method for population genetics and disease association studies.

  13. Impact of the population implosion

    Energy Technology Data Exchange (ETDEWEB)

    Kilpatrick, J.J.

    1978-03-01

    Mr. Kilpatrick evaluates Paul R. Ehrlich's thesis that mankind will breed itself into oblivion. Mr. Ehrlich in his book, ''The Population Bomb,'' sees population control as the only answer to mass starvation in such countries as India, Africa, Central America, and China. Mr. Kilpatrick says the U.S. has drifted toward the goal of zero population growth, where the total births per woman have dropped to 1.8. In Denmark, Finland, Sweden, Belgium, West Germany, Great Britain, and Austria, the births per woman have dropped even lower than in the U.S. The decline in births is attributed to women joining the workforce, advancement of birth control measures, and high costs of medical care, housing, and education. Women marrying later and fashion are also factors. Zero population growth will have gross implications on the financial markets in the U.S. Pension systems will be directly affected. The author cites the dilemma of the Social Security system when a smaller proportion of young people are contributing to it. Household savings trends will alter; new construction, new plant and equipment investment, and consumer loans will have to be reconsidered. If the trend toward implosion continues and social services demand an increasing share of the Federal budget, other interests will have to yield and the author cites the budget for national defense as declining. Some prophets feel the population decline is nothing of concern, the author concludes. (MCW)

  14. Political economy of population growth.

    Science.gov (United States)

    Mehta, S; Mehta, H S

    1987-01-01

    Tracing the origin of political economy as a class-science, this paper focuses on the political economy of population growth. Exposing the limitations of Malthusian ideas and their invalidity even for the capitalist economies, it discusses the subsequent revival of the Malthusian model during the period of de-colonization and the misinterpretation of the relationship between population growth and development in the developing and developed countries. Taking India, China, and Japan as some case studies, the paper examines the relationship between birth rate levels and some correlates. It elaborates on the Indian experience, emphasizing the association of population growth with poverty and unemployment and lays bare some of the hidden causes of these phenomena. The authors examine some interstate variations in India and identify constraints and prospects of the existing population policy. The paper proposes outlines of a democratic population policy as an integral part of India's development strategy which should recognize human beings not simply as consumers but also as producers of material values. It pleads for 1) restructuring of property relations; 2) bringing down the mortality rates and raising of the literacy levels, especially among females; and 3) improving nutritional levels, as prerequisites for bringing down birth rates.

  15. Statistical Mechanics of Zooplankton.

    Science.gov (United States)

    Hinow, Peter; Nihongi, Ai; Strickler, J Rudi

    2015-01-01

    Statistical mechanics provides the link between microscopic properties of many-particle systems and macroscopic properties such as pressure and temperature. Observations of similar "microscopic" quantities exist for the motion of zooplankton, as well as many species of other social animals. Herein, we propose to take average squared velocities as the definition of the "ecological temperature" of a population under different conditions on nutrients, light, oxygen and others. We test the usefulness of this definition on observations of the crustacean zooplankton Daphnia pulicaria. In one set of experiments, D. pulicaria is infested with the pathogen Vibrio cholerae, the causative agent of cholera. We find that infested D. pulicaria under light exposure have a significantly greater ecological temperature, which puts them at a greater risk of detection by visual predators. In a second set of experiments, we observe D. pulicaria in cold and warm water, and in darkness and under light exposure. Overall, our ecological temperature is a good discriminator of the crustacean's swimming behavior.

  16. Statistical Mechanics of Zooplankton.

    Directory of Open Access Journals (Sweden)

    Peter Hinow

    Full Text Available Statistical mechanics provides the link between microscopic properties of many-particle systems and macroscopic properties such as pressure and temperature. Observations of similar "microscopic" quantities exist for the motion of zooplankton, as well as many species of other social animals. Herein, we propose to take average squared velocities as the definition of the "ecological temperature" of a population under different conditions on nutrients, light, oxygen and others. We test the usefulness of this definition on observations of the crustacean zooplankton Daphnia pulicaria. In one set of experiments, D. pulicaria is infested with the pathogen Vibrio cholerae, the causative agent of cholera. We find that infested D. pulicaria under light exposure have a significantly greater ecological temperature, which puts them at a greater risk of detection by visual predators. In a second set of experiments, we observe D. pulicaria in cold and warm water, and in darkness and under light exposure. Overall, our ecological temperature is a good discriminator of the crustacean's swimming behavior.

  17. Population dynamics of bacterial persistence.

    Directory of Open Access Journals (Sweden)

    Pintu Patra

    Full Text Available Persistence is a prime example of phenotypic heterogeneity, where a microbial population splits into two distinct subpopulations with different growth and survival properties as a result of reversible phenotype switching. Specifically, persister cells grow more slowly than normal cells under unstressed growth conditions, but survive longer under stress conditions such as the treatment with bactericidal antibiotics. We analyze the population dynamics of such a population for several typical experimental scenarios, namely a constant environment, shifts between growth and stress conditions, and periodically switching environments. We use an approximation scheme that allows us to map the dynamics to a logistic equation for the subpopulation ratio and derive explicit analytical expressions for observable quantities that can be used to extract underlying dynamic parameters from experimental data. Our results provide a theoretical underpinning for the study of phenotypic switching, in particular for organisms where detailed mechanistic knowledge is scarce.

  18. Keynes, population, and equity prices.

    Science.gov (United States)

    Tarascio, V J

    1985-01-01

    Keynes in 1937 examined the phenomenon of the Great Depression from a longrun perspective in contradiction to the "General Theory," where the focus was on the shortrun. "Some Economic Consequences of a Declining Population," Keynes' article, reveals the context in which the "General Theory" was written. In the "General Theory," the focus is on short-term fluctuations, i.e., business cycles, but Keynes fails to provide any theoretical explanation as to why the depression of the 1930s was so severe and intractable. In the 1937 article, the depression is seen as the result of the combined effects of a decline in longrun growth due to population growth decline and a shortrun cyclical decline, together producing severe economic consequences. What is important for the purposes of this discussion is the implication, within the context of the 1937 article, that not only was the stock market crash of 1929 related to population change (with its accompanying collapse in expectations) but that, in general, changes in the rate of growth of population are accompanied by stock price movements in the same direction. The remainder of the discussion is devoted to a simple empirical test of this relationship. The data used are population size (POP), defined as the total residential population in the US from 1870-1979, and the Standard and Poor 500 Stock index (SP) for the corresponding 109-year period. In addition, a 3rd series was constructed, a price deflated Standard and Poor index (RSP) with a base period of 1870, to account for possible inflationary distortion of the index. The empirical results do not invalidate the hypothesis that population growth rates affect equity markets. In fact, there seems to be strong evidence that they are related in a manner suggestive of Keynes' intutition, namely, that the stock market crash of 1929 was due to factors more fundamental than those often perceived from a shortrun perspective. According to Keynes (1937), population is the most

  19. Rapid population increase in an introduced muskox population, West Greenland

    Directory of Open Access Journals (Sweden)

    Carsten Riis Olesen

    1993-10-01

    Full Text Available In 1962 and 1965, 27 (13 and 14 muskox yearlings were translocated from East Greenland (71°N to the Angujaartorfiup Nunaa range in West Greenland (67°N. Angujaartorfiup Nunaa is a 6600 km2 icefree, continental area where caribou are indigenous. The climate is strictly continental with a minimum of precipitation but with abundant vegetation. Aerial surveys in 1990 documented that the muskox population has increased to 2600 heads despite quota-based harvesting since 1988. The annual quota was 200, 300 and 400 for 1988, 1989 and 1990, respectively. Distribution of muskoxen shows a significant preference for low altitude habitats southeast of Kangerlussuaq Airport and around Arnangarnup Qoorua (Paradise valley. Annual population increment averages 30% and the calf crop is around 24% of the population. Yearling recruitment in the population reveals that calf mortality during winter is very limited. About half of the 1-year-old females are served and they eventually give birth to their first calf when they turn 2 years old. With half of the 2-year-old females reproducing, the calf/cow ration ranges between 0.9 and 1.0.

  20. Experimental assessment of environmental influences on the stable isotopic composition of Daphnia pulicaria and their ephippia

    Directory of Open Access Journals (Sweden)

    J. Schilder

    2015-02-01

    δ15N values of ephippia and Daphnia between the 12 °C and 20 °C treatments, but the δ18O values of Daphnia and ephippia were on average 1.2‰ lower at 20 °C compared with 12 °C. We conclude that the stable isotopic composition of Daphnia ephippia provides information on that of the parent Daphnia and of the food and water they were exposed to, with small offsets between Daphnia and ephippia relative to variations in Daphnia stable isotopic composition reported from downcore studies. However, our experiments also indicate that temperature may have a minor influence on the δ13C, δ15N and δ18O values of Daphnia body tissue and ephippia. This aspect deserves attention in further controlled experiments.

  1. Cyanobacterial protease inhibitor microviridin J causes a lethal molting disruption in Daphnia pulicaria.

    Science.gov (United States)

    Rohrlack, Thomas; Christoffersen, Kirsten; Kaebernick, Melanie; Neilan, Brett A

    2004-08-01

    Laboratory experiments identified microviridin J as the source of a fatal molting disruption in Daphnia species organisms feeding on Microcystis cells. The molting disruption was presumably linked to the inhibitory effect of microviridin J on daphnid proteases, suggesting that hundreds of further cyanobacterial protease inhibitors must be considered potentially toxic to zooplankton.

  2. The Why and How of Population Education

    Science.gov (United States)

    Seffrin, John R.

    1975-01-01

    Discusses the importance of instructional programs concerning population education and describes population growth in the United States, the biological reasons for the overpopulation problem, and the role of the health educator in population education. (BD)

  3. A new population of FRIIs?

    Science.gov (United States)

    Sambruna, Rita

    2006-10-01

    Unification scenarios explain various flavors of radio galaxies and quasars with orientation-dependent obscuration effects. Type-2 FRII galaxies contain a quasar seen through a dusty molecular torus aligned with the radio jet. However, there exist a population of FRIIs, found with Spitzer, that does not fit into this scheme. These FRIIs exhbit high-excitation nuclear optical emission lines, but weak 15um luminosities. One possibility is very large obscuration; alternatively, they may be a genuinely different population. XMM spectroscopy and Chandra imaging will discriminate between the two scenarios.

  4. Models of ungulate population dynamics

    Directory of Open Access Journals (Sweden)

    L. L. Eberhardt

    1991-10-01

    Full Text Available A useful theory for analyzing ungulate population dynamics is available in the form of equations based on the work of A. J. Lotka. Because the Leslie matrix model yields identical results and is widely known, it is convenient to label the resulting equations as the "Lotka-Leslie" model. The approach is useful for assessing population trends and attempting to predict the outcomes of various management actions. A broad list of applications to large mammals, and two examples specific to caribou are presented with a simple spreadsheet approach to calculations.

  5. Population education for social betterment.

    Science.gov (United States)

    Mukhi, S

    1983-01-26

    In India primary education has increased 3 times in the last 30 years. Over this same period middle school education has increased 4 times, higher secondary education 5 times, and university level education over 6 times. The number of universities alone increased from 19 in 1950 to 118 by 1981. The inconsistencies brought about by rapid population growth may be judged by the fact that while the number of institutions and the enrollment of students has expanded beyond measure, the number of illiterate persons has risen from 386 million in 1971 to 446 million in 1981. Clearly, education is vital for human resource development. In political terms, human resource development prepares a population for adult participation in political processes. From social and cultural perspectives, the development of human resources helps people to lead fuller and richer lives. Population means people, and people need food, clothing, homes, education, transportation, health services, and jobs. As long as a country's resources can satisfy the essential needs of its population, there is no population problem. If the population grows faster than the rate at which the basic needs of each individual can be met, the buildup of such a situation produces a crisis of gigantic dimensions. To meet basic requirements, India needs to provide annually an additional 12 million tons of foodgrains, 188 million meters of cloth, 2.5 million houses, along with schools, teachers, and jobs over and above what is currently available. Another need is for fresh air, pure water, and space to live in. The question is how is this need to be met when the earth is a finite sphere. What will happen when the world's 3.5 billion people double into a staggering 7 billion by the end of the 20th century. It is because of this concern for family well being and the betterment of human resources that the Family Planning Association of India has since 1969 undertaken innovative pilot programs in popultion education for the

  6. Structure of African elephant populations

    DEFF Research Database (Denmark)

    Siegismund, H R; Arctander, P

    1996-01-01

    The structure of elephant populations from east and south Africa has been analyzed by Georgiadis et al. (1994) on the basis of restriction site variation of mitochondrial DNA. They used F statistics based on identity by descent in tests for subdivision and reached the conclusion that there was a ......The structure of elephant populations from east and south Africa has been analyzed by Georgiadis et al. (1994) on the basis of restriction site variation of mitochondrial DNA. They used F statistics based on identity by descent in tests for subdivision and reached the conclusion...

  7. Seminar on Egypt population policy.

    Science.gov (United States)

    Kantner, J F

    1984-01-01

    The information and viewpoints presented at the Seminar on Egypt Population Policy held in Cairo on October 16-18 were summariezed and critically assessed. The seminar was organized by the International Union for the Scientific Study of Population's Committee on the Utilization ofDemographic Knowlege in Policy Formulation and Planning for the purpose of assessing the policy making the utility of social science and demographc knowledge with specific reference to Egypt's family planning program. The seminar was attended by demographers, social scientists, and experienced policy makers, and the discussion was highly focused. Seminar papers and discussions sought to clarify Egypt's current demographic situation, attempted to use sample survey data to identifyfertility determinants, analyzed Egypt's policyresponses to the population problem, assessed the national family planning program, identified the type of knowledge available for policy making, and noted areas where policy relevant information is lacking. Evidence presented at the seminar indicated that Egyptian fertility is still high and that corrected the total fertility rate for 1980 was close to 6. Since, 1960, fertility declined in all regions of the country, but between 1976-80 the decline decelerated. This deceleration appears to be a temporary phenonemon. There is evidence that the age at marriage is increasing, that the population is motivated to use contraception when desired family size is reached, that contraceptive use is cost sensitive, and that the overall decline in fertility since the 1960s occurred in all parts of the country. Papers which presented analyses of fertility determinants, based on sample survey data, provided little useful insight for policy formulation. The studies indicate that the impact of family planning services on different segments of the population varies, and that these impacts may be increased if social and economic development persists. The preception of the population

  8. Populism and Education in Norway.

    Science.gov (United States)

    Lauglo, Jon

    1995-01-01

    Examines the influence of Norwegian populism, with its emphasis on rural roots and community values, on the development of Norwegian education. Discusses populist traits in Norwegian society and populist educational features: strong common school, weak academic tradition, use of New Norse vernacular, importance of informal learning at home,…

  9. Populism in High School Textbooks

    Science.gov (United States)

    Peiser, Andrew C.

    1973-01-01

    The purpose of this study was to determine whether one area of United States history--Populism and Populists--is accurately presented in nine widely used current American history high school textbooks. Another objective was to devise a system that could be used to make such a determination for any history text. (Author)

  10. Better Reporting of Population Issues.

    Science.gov (United States)

    Population Education in Asia and the Pacific Newsletter and Forum, 1990

    1990-01-01

    Presented are the focus and the annotated issues from a workshop on new perspectives in population education for 19 Pacific Island journalists, both print and broadcast, from government and nongovernment agencies. The regional workshop was jointly organized by UNESCO and the South Pacific Commission during February 1990, in Auckland, New Zealand.…

  11. [Nuptiality among Brazil's black population].

    Science.gov (United States)

    Berquo, E

    1987-08-01

    Data from a three percent sample of the 1980 census of Brazil are used to analyze nuptiality trends by ethnic group. The focus is on the homogamy of marriage by color and age and on the marriage patterns of the black population.

  12. Gender, Education and Population Flows

    DEFF Research Database (Denmark)

    Bennike, Kathrine Bjerg; Faber, Stine Thidemann; Nielsen, Helene Pristed

    During the Danish Presidency for the Nordic Council of Ministers in 2015, attention was drawn towards challenges and best practice examples in relation to gender, education and population flows in peripheral areas throughout the Nordic countries - Norway, Denmark, Sweden, Finland, Iceland...

  13. Genetic structure of forensic populations.

    OpenAIRE

    Morton, N. E.

    1992-01-01

    DNA-based identification depends on the probability that two different individuals have the same phenotype, which is given by kinship theory. Together with the large and consistent body of evidence on human population structure, kinship theory provides a sound basis for forensic use of DNA markers.

  14. Communication Disorders in Multicultural Populations.

    Science.gov (United States)

    Battle, Dolores E., Ed.

    This text on communication disorders in multicultural populations is intended to provide a framework for speech language pathologists and audiologists in providing services to persons from different cultures and racial backgrounds. The 11 papers are grouped into 2 parts. Papers in part I provide an overview of the major cultural groups in the…

  15. Genebanking seeds from natural populations

    Science.gov (United States)

    Conventional storage protocols have been developed to preserve genetic diversity of seeds of crops in genebanks. These same principles have been applied to preserve seeds from wild populations. While most principles for conventional storage protocols are applicable to a broad range of wild species...

  16. Synthetic population system user guide

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, D.J.

    1998-03-01

    The Los Alamos National Laboratory (LANL) TRansportation Analysis SIMulatiuon System (TRANSIMS) synthetic population system (SYN) is designed to produce populations (family households, non-family households, and group quarters) that are statistically equivalent to actual populations when compared at the level of block group or higher. The methodology used by this system is described in a report entitled Creating Synthetic Baseline Populations. The inputs to the system are US Census Bureau data (STF3A and PUMS) and MABLE/GEOCORR data. Census Bureau STF3A and PUMS data formats are commonly used and are available on CD-ROM from the Census Bureau. These data inputs will not be described in any detail in this guide. The primary function of MABLE/GEOCORR data is to cross-reference STF3 block group data to PUMS areas. The outputs of the system are files that contain family household, non-family household, and group quarters data in the form of household and person records. SYN will run on a variety of Unix platforms.

  17. Flood trends and population dynamics

    Science.gov (United States)

    Di Baldassarre, G.

    2012-04-01

    Since the earliest recorded civilizations, such as those in Mesopotamia and Egypt that developed in the fertile floodplains of the Tigris and Euphrates and Nile rivers, humans tend to settle in flood prone areas as they offer favorable conditions for economic development. However, floodplains are also exposed to flood disasters that might cause severe socio-economic and environmental damages not to mention losses of human lives. A flood event turns to be a disaster when it coincides with a vulnerable environment exceeding society's capacity to manage the adverse consequences. This presentation discusses the link between hydrological risk and population change by referring to the outcomes of scientific works recently carried out in Africa and Europe. More specifically, it is shown that the severity of flood disasters, currently affecting more than 100 million people a year, might be seriously exacerbated because of population change. In fact, flood exposure and/or vulnerability might increase because of rapid population growth (and its spatial and temporal dynamics, e.g. urbanization) in the African continent and because of population ageing in many European countries. Lastly, timely and economically sustainable actions to mitigate this increasing hydrological risk are critically evaluated.

  18. Modeling Population Growth and Extinction

    Science.gov (United States)

    Gordon, Sheldon P.

    2009-01-01

    The exponential growth model and the logistic model typically introduced in the mathematics curriculum presume that a population grows exclusively. In reality, species can also die out and more sophisticated models that take the possibility of extinction into account are needed. In this article, two extensions of the logistic model are considered,…

  19. Population, poverty, and climate change

    OpenAIRE

    Das Gupta, Monica

    2013-01-01

    The literature is reviewed on the relationships between population, poverty, and climate change. While developed countries are largely responsible for global warming, the brunt of the fallout will be borne by the developing world, in lower agricultural output, poorer health, and more frequent natural disasters. Carbon emissions in the developed world have leveled off, but are projected to ...

  20. Reproductive effort in viscous populations

    NARCIS (Netherlands)

    Pen, Ido

    2000-01-01

    Here I study a kin selection model of reproductive effort, the allocation of resources to fecundity versus survival, in a patch-structured population. Breeding females remain in the same patch for life. Offspring have costly, partial long-distance dispersal and compete for breeding sites, which beco

  1. Population conference: consensus and conflict.

    Science.gov (United States)

    Willson, P D

    1984-01-01

    The United Nations-sponsored International Conference on Population held in Mexico City was both a rejection and an affirmation of a new policy of the Reagan administration. The policy denies international family planning funds to nongovernmental organizations that perform or actively promote abortion as a family planning method in other nations. A compromise statement was accepted urging governments to take appropriate measures to discourage abortion as a family planning method and when possible to provide for the humane treatment and counseling of women ho resorted to abortion. The statement on abortion was 1 of 88 reccomendations approved by the conference. The commitment expressed in the 10-year-old World Population Plan of Action to the rights and responsiblity to all people as reaffirmed. The conference also endorsed family life education and sex education as well as suitable family planning, information and services for adolescents, with due consideration given to the role, rights and obligations of parents. Increased support for international population and family planning programs was urged and World Bank President, Clausen, urged a 4-fold increase in international funding by the year 2000. Most of the conference's recommendations re devoted to the broad range of population policy issues, including morbidity and mortality, international and internal migration, the relationship between population and economic development and the status of women. The purpose of the recommendations is to increase the momentum of international support. The Mexico City conference was characterized by a remarkable degree of consensus about population policies with respect to integration with economic development, the need to respect individual rights and the recognition that all nations have sovereign rights to develop and implement their own population policies. Conflict and controversy arose in the areas of the arms race and the Middle East. The US position on abortion funding

  2. Population and the Colombian economy.

    Science.gov (United States)

    Sanders, T G

    1983-01-01

    Colombia is the only one of the 6 most populous Latin American countries that is currently free of major economic crisis requiring an agreement with the International Monetary Fund. The difference in the economic performances of these countries is relative, since the rate of growth in the Colombian economy was only 1.5% in 1982. Yet, Colombia seems to have weathered the international recession better than most. The crisis atmosphere in the rest of Latin America, triggered by overall economic decline, high rates of inflation, and an indebtedness that soaks up much of export earnings to service it, is lacking in Colombia or present in lesser degree. If Colombia can strengthen its political performance and tighten national unity, it could move through the 1980s with considerable confidence and success in economic development. Colombia differs little from other major Latin American countries with regard to traditionalism and modernization. Most Colombians are secularized. Colombia is far ahead of most comparable Latin American countries in fertility control. The lower rate of population increase defines the extent to which the economy must provide education, health, food, and jobs. 2 other factors are essential for understanding the current situation in Colombia and its prospects for the 1980s. Government policy in the 1970s opted for an austerity program while the other countries were growing rapidly, in large part through borrowed resources. A 2nd factor is the prospect of attaining autonomy in energy production. These special characteristics--population, public policy, and energy--are discussed. Since the mid 1960s Colombia has functioned with 3 family planning programs. Their existence makes contraception easily available to the population generally. In 1960 Colombia had a higher total fertility rate (TFR) 7.0, than either Venezuela (6.6) or Brazil (5.3), but by 1976 its TFR was down to 4.1, while Venezuela's (4.8) and Brazil's (4.3) were now higher. On balance

  3. The Middle East population puzzle.

    Science.gov (United States)

    Omran, A R; Roudi, F

    1993-07-01

    An overview is provided of Middle Eastern countries on the following topics; population change, epidemiological transition theory and 4 patterns of transition in the middle East, transition in causes of death, infant mortality declines, war mortality, fertility, family planning, age and sex composition, ethnicity, educational status, urbanization, labor force, international labor migration, refugees, Jewish immigration, families, marriage patterns, and future growth. The Middle East is geographically defined as Bahrain, Egypt, Iraq, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, Syria, United Arab Emirates, Yemen, Gaza and the West Bank, Iran, Turkey, and Israel. The Middle East's population grew very little until 1990 when the population was 43 million. Population was about doubled in the mid-1950s at 80 million. Rapid growth occurred after 1950 with declines in mortality due to widespread disease control and sanitation efforts. Countries are grouped in the following ways: persistent high fertility and declining mortality with low to medium socioeconomic conditions (Jordan, Oman, Syria, Yemen, and the West Bank and Gaza), declining fertility and mortality in intermediate socioeconomic development (Egypt, Lebanon, Turkey, and Iran), high fertility and declining mortality in high socioeconomic conditions (Bahrain, Iraq, Kuwait, Qatar, Saudi Arabia, and the United Arab Emirates), and low fertility and mortality in average socioeconomic conditions (Israel). As birth and death rates decline, there is an accompanying shift from communicable diseases to degenerative diseases and increases in life expectancy; this pattern is reflected in the available data from Egypt, Kuwait, and Israel. High infant and child mortality tends to remain a problem throughout the Middle East, with the exception of Israel and the Gulf States. War casualties are undetermined, yet have not impeded the fastest growing population growth rate in the world. The average fertility is 5 births

  4. Population and the Colombian economy.

    Science.gov (United States)

    Sanders, T G

    1983-01-01

    Colombia is the only one of the 6 most populous Latin American countries that is currently free of major economic crisis requiring an agreement with the International Monetary Fund. The difference in the economic performances of these countries is relative, since the rate of growth in the Colombian economy was only 1.5% in 1982. Yet, Colombia seems to have weathered the international recession better than most. The crisis atmosphere in the rest of Latin America, triggered by overall economic decline, high rates of inflation, and an indebtedness that soaks up much of export earnings to service it, is lacking in Colombia or present in lesser degree. If Colombia can strengthen its political performance and tighten national unity, it could move through the 1980s with considerable confidence and success in economic development. Colombia differs little from other major Latin American countries with regard to traditionalism and modernization. Most Colombians are secularized. Colombia is far ahead of most comparable Latin American countries in fertility control. The lower rate of population increase defines the extent to which the economy must provide education, health, food, and jobs. 2 other factors are essential for understanding the current situation in Colombia and its prospects for the 1980s. Government policy in the 1970s opted for an austerity program while the other countries were growing rapidly, in large part through borrowed resources. A 2nd factor is the prospect of attaining autonomy in energy production. These special characteristics--population, public policy, and energy--are discussed. Since the mid 1960s Colombia has functioned with 3 family planning programs. Their existence makes contraception easily available to the population generally. In 1960 Colombia had a higher total fertility rate (TFR) 7.0, than either Venezuela (6.6) or Brazil (5.3), but by 1976 its TFR was down to 4.1, while Venezuela's (4.8) and Brazil's (4.3) were now higher. On balance

  5. Pharmacogenetics in the Brazilian population

    Directory of Open Access Journals (Sweden)

    Guilherme eSuarez-Kurtz

    2010-10-01

    Full Text Available Brazil is the 5th largest country in the world and its present population, in excess of 190 million, is highly heterogeneous, as a result of centuries of admixture between Amerindians, Europeans and Sub-Saharan Africans. The estimated individual proportions of biogeographical ancestry vary widely and continuously among Brazilians, most individuals - irrespective of self-identification as White, Brown or Black, the major categories of the Brazilian Census race/color system - having significant degrees of European and African ancestry, while a sizeable number display also Amerindian ancestry. These features have important pharmacogenetic (PGx implications: first, extrapolation of PGx data from relatively well-defined ethnic groups is clearly not applicable to the majority of Brazilians; second, the frequency distribution of polymorphisms in pharmacogenes (e.g. CYP3A5, CYP2C9, GSTM1, ABCB1, GSTM3, VKORC, etc varies continuously among Brazilians and is not captured by race/color self-identification; third, the intrinsic heterogeneity of the Brazilian population must be acknowledged in the design and interpretation of PGx studies in order to avoid spurious conclusions based on improper matching of study cohorts. The peculiarities of PGx in Brazilians are illustrated with data for different therapeutic groups, such as anticoagulants, HIV-protease inhibitors and nonsteroidal antinflammatory drugs, and the challenges and advantages created by population admixture for the study and implementation of PGx are discussed. PGx data for Amerindian groups and Brazilian-born, first generation Japanese are presented to illustrate the rich diversity of the Brazilian population. Finally, I introduce the reader to the Brazilian Pharmacogenetic Network or Refargen (www.refargen.org.br, a nationwide consortium of research groups, with the mission to provide leadership in PGx research and education in Brazil, with a population health impact.

  6. Pharmacogenetics in the brazilian population.

    Science.gov (United States)

    Suarez-Kurtz, Guilherme

    2010-01-01

    Brazil is the fifth largest country in the world and its present population, in excess of 190;million, is highly heterogeneous, as a result of centuries of admixture between Amerindians, Europeans, and Sub-Saharan Africans. The estimated individual proportions of biogeographical ancestry vary widely and continuously among Brazilians: most individuals, irrespective of self-identification as White, Brown or Black - the major categories of the Brazilian Census "race/color" system - have significant degrees of European and African ancestry, while a sizeable number display also Amerindian ancestry. These features have important pharmacogenetic (PGx) implications: first, extrapolation of PGx data from relatively well-defined ethnic groups is clearly not applicable to the majority of Brazilians; second, the frequency distribution of polymorphisms in pharmacogenes (e.g., CYP3A5, CYP2C9, GSTM1, ABCB1, GSTM3, VKORC, etc) varies continuously among Brazilians and is not captured by race/color self-identification; third, the intrinsic heterogeneity of the Brazilian population must be acknowledged in the design and interpretation of PGx studies in order to avoid spurious conclusions based on improper matching of study cohorts. The peculiarities of PGx in Brazilians are illustrated with data for different therapeutic groups, such as anticoagulants, HIV protease inhibitors and non-steroidal antinflammatory drugs, and the challenges and advantages created by population admixture for the study and implementation of PGx are discussed. PGx data for Amerindian groups and Brazilian-born, first-generation Japanese are presented to illustrate the rich diversity of the Brazilian population. Finally, I introduce the reader to the Brazilian Pharmacogenetic Network or Refargen, a nation-wide consortium of research groups, with the mission to provide leadership in PGx research and education in Brazil, with a population health impact. PMID:21833165

  7. Rising population and environmental degradation.

    Science.gov (United States)

    Mitra, A

    Environmental degradation is becoming an increasingly ominous threat to the well-being of India's population, and excessive population growth is the primary cause of environmental deterioration. Population growth increases the need to produce consumer products and this need, in turn, intensifies the trend to over-exploit and misuse environmental resources. Efforts to control population growth through contraceptive technology and the expansion of family planning services and to control environmental deterioration via technology and management will meet with little success. A prerequisite for controlling these dual problems is the improvement of living conditions for the masses. Only when individuals acquire a sense of security and have the prospect of acquiring a share in the resources of the country will they be willing to conserve and renew resources and to limit their fertility. Viewed from this prospective, various factors and trends in India can be assessed as either negative or positive. Positive factors, i.e., those which enhance economic oppotunities and security for the general population, include the recent achievement of economic grothw in the country's agricultural and industrial sectors, the growth in technological knowledge, and the expansion of the rural and urban infrastructure. Negative factors include 1) the increase in income inequality, 2) the refusal to grant distributive justice to the masses, 3) the lack of education which impedes public understanding and awareness of environmental issues and promotes under utilization of community and social services, 4) the high unemployment rate which prevents individuals from developing a sense of responsibility and self respect; and 5) the refusal of the government to establish fuel policies to halt the growing problem of deforestation. Major environmental problems include pollution and congestion associated with the geographical concentration of industry; the destruction of the forests which leads to

  8. Modeling Approaches for Describing Microbial Population Heterogeneity

    OpenAIRE

    Lencastre Fernandes, Rita; Gernaey, Krist; Jensen, Anker Degn; Nopens, Ingmar

    2013-01-01

    Although microbial populations are typically described by averaged properties, individual cells present a certain degree of variability. Indeed, initially clonal microbial populations develop into heterogeneous populations, even when growing in a homogeneous environment. A heterogeneous microbial population consists of cells in different states, and it implies a heterogeneous distribution of activities (e.g. respiration, product yield), including different responses to extracellular stimuli. ...

  9. Developing STR databases on structured populations: the native South Siberian population versus the Russian population.

    Science.gov (United States)

    Zhivotovsky, Lev A; Malyarchuk, Boris A; Derenko, Miroslava V; Wozniak, Marcin; Grzybowski, Tomasz

    2009-09-01

    Developing a forensic DNA database on a population that consists of local ethnic groups separated by physical and cultural barriers is questionable as it can be genetically subdivided. On the other side, small sizes of ethnic groups, especially in alpine regions where they are sub-structured further into small villages, prevent collecting a large sample from each ethnic group. For such situations, we suggest to obtain both a total population database on allele frequencies across ethnic groups and a list of theta-values between the groups and the total data. We have genotyped 558 individuals from the native population of South Siberia, consisting of nine ethnic groups, at 17 autosomal STR loci of the kit packages AmpFlSTR SGM Plus i, Cyrillic AmpFlSTR Profiler Plus. The groups differentiate from each other with average theta-values of around 1.1%, and some reach up to three to four percent at certain loci. There exists between-village differentiation as well. Therefore, a database for the population of South Siberia is composed of data on allele frequencies in the pool of ethnic groups and data on theta-values that indicate variation in allele frequencies across the groups. Comparison to additional data on northeastern Asia (the Chukchi and Koryak) shows that differentiation in allele frequencies among small groups that are separated by large geographic distance can be even greater. In contrast, populations of Russians that live in large cities of the European part of Russia are homogeneous in allele frequencies, despite large geographic distance between them, and thus can be described by a database on allele frequencies alone, without any specific information on theta-values.

  10. Stability of Evolving Agent Populations

    CERN Document Server

    Briscoe, G

    2007-01-01

    Stability is perhaps the most desired feature in the systems that we design. It is important for us to be able to predict the response of a Multi-Agent System (MAS) to various environmental conditions prior to its actual deployment. The Chli-DeWilde agent stability measure views a MAS as a discrete time Markov chain with a potentially unknown transition probabilities. A MAS is considered to be stable when its state, a stochastic process, has converged to an equilibrium distribution. We investigate an extension of their agent stability definition to include MASs with evolutionary dynamics, focusing on evolving agent populations. Additionally, using our extended agent stability measure, we construct an entropy-based definition for the degree of instability. An example system, the Digital Ecosystem, is considered in detail to investigate the stability of an evolving agent population through simulations. The results are consistent with the original Chli-DeWilde measure.

  11. Stochastic problems in population genetics

    CERN Document Server

    Maruyama, Takeo

    1977-01-01

    These are" notes based on courses in Theoretical Population Genetics given at the University of Texas at Houston during the winter quarter, 1974, and at the University of Wisconsin during the fall semester, 1976. These notes explore problems of population genetics and evolution involving stochastic processes. Biological models and various mathematical techniques are discussed. Special emphasis is given to the diffusion method and an attempt is made to emphasize the underlying unity of various problems based on the Kolmogorov backward equation. A particular effort was made to make the subject accessible to biology students who are not familiar with stochastic processes. The references are not exhaustive but were chosen to provide a starting point for the reader interested in pursuing the subject further. Acknowledgement I would like to use this opportunity to express my thanks to Drs. J. F. Crow, M. Nei and W. J. Schull for their hospitality during my stays at their universities. I am indebted to Dr. M. Kimura...

  12. Cancer patterns in Inuit populations

    DEFF Research Database (Denmark)

    Melbye, M.; Friborg, Jeppe Tang

    2008-01-01

    a distinct pattern, characterised by a high risk of Epstein-Barr virus-associated carcinomas of the nasopharynx and salivary glands, and a low risk of tumours common in white populations, including cancer of the prostate, testis, and haemopoietic system. Both genetic and environmental factors seem......, and reproductive factors. This Review will briefly summarise the current knowledge on cancer epidemiology in Inuit populations, with emphasis on the characteristic Inuit types of cancer Udgivelsesdato: 2008/9...... to be responsible for this pattern. During the second half of the 20th century, Inuit societies underwent major changes in lifestyle and living conditions, and the risk of lifestyle-associated tumours, especially cancers of the lung, colon, and breast, increased considerably after changes in smoking, diet...

  13. Dust Devil Populations and Statistics

    Science.gov (United States)

    Lorenz, Ralph D.; Jackson, Brian K.

    2016-08-01

    The highly-skewed diameter and pressure drop distributions of dust devils on Earth and Mars are noted, and challenges of presenting and comparing different types of observations are discussed. The widely-held view that Martian dust devils are larger than Earth's is critically assessed: the question is confounded somewhat by different observation techniques, but some indication of a {˜} 3x larger population on Mars is determined. The largest and most intense (in a relative pressure sense) devils recorded are on Mars, although the largest reported number density is on Earth. The difficulties of concepts used in the literature of `average' diameter, pressure cross section, and area fraction are noted in the context of estimating population-integral effects such as dust lifting.

  14. Right wing populism in Denmark

    DEFF Research Database (Denmark)

    Siim, Birte; Meret, Susi

    2016-01-01

    Peoples’ Party managed to mobilise the Danish voters. But while scholarly literature mostly focussed on political parties we propose that an important contribution to the ideological development of populism also comes from movements, such as The Association for Freedom of Speech (Trykkefrihedsselskabet...... between Danish populism and welfare nationalism/national politics of belonging, focusing on the intersections of the nation, the people and the welfare state from historical perspectives. To what extent is it possible to identify a particular Nordic exceptionalism that links to Social democracy? To what...... and with accommodating ethno-cultural and religious diversity. Mainstream political parties have since the 1990s been engaged in re-thinking and reframing the relation between the national, the democratic and the social questions. Arguably, it is within these cleavages that the influential Scandinavian populist Danish...

  15. Statistical thermodynamics of clustered populations.

    Science.gov (United States)

    Matsoukas, Themis

    2014-08-01

    We present a thermodynamic theory for a generic population of M individuals distributed into N groups (clusters). We construct the ensemble of all distributions with fixed M and N, introduce a selection functional that embodies the physics that governs the population, and obtain the distribution that emerges in the scaling limit as the most probable among all distributions consistent with the given physics. We develop the thermodynamics of the ensemble and establish a rigorous mapping to regular thermodynamics. We treat the emergence of a so-called giant component as a formal phase transition and show that the criteria for its emergence are entirely analogous to the equilibrium conditions in molecular systems. We demonstrate the theory by an analytic model and confirm the predictions by Monte Carlo simulation.

  16. Hypernatremia in the geriatric population

    OpenAIRE

    Taffet, George

    2014-01-01

    Maulin K Shah,1 Biruh Workeneh,1,2 George E Taffet1,3 1Department of Internal Medicine, 2Department of Nephrology, 3Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA Abstract: Hypernatremia in the geriatric population is a common disorder associated with significant morbidity and mortality. Older people are predisposed to developing hypernatremia because of age-related physiologic changes such as decreased thirst drive, impaired urinary concentrating...

  17. Hypernatremia in the geriatric population

    OpenAIRE

    Shah MK; Workeneh B; Taffet GE

    2014-01-01

    Maulin K Shah,1 Biruh Workeneh,1,2 George E Taffet1,3 1Department of Internal Medicine, 2Department of Nephrology, 3Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA Abstract: Hypernatremia in the geriatric population is a common disorder associated with significant morbidity and mortality. Older people are predisposed to developing hypernatremia because of age-related physiologic changes such as decreased thirst drive, impaired urinary concentrating ability...

  18. Bioethics, population studies, and geneticophobia

    OpenAIRE

    Salzano, Francisco M.

    2015-01-01

    In any research of human populations, the classical principles of bioethics (respect for autonomy, non-maleficence, beneficence, proportionality between risks and benefits, and justice) should be strictly followed. The question of individual and/or community rights should also be considered, as well as some neglected rights, such as the right to benefit from progress in science and technology and the right to know the nature of the group’s biological and cultural history; however, in their ur...

  19. Childhood gastroenteritis: a population study.

    OpenAIRE

    Isaacs, D; Day, D.; Crook, S.

    1986-01-01

    A prospective study of gastroenteritis based on a population was carried out for 12 months on over 7000 children in general practice. The incidence of gastroenteritis was highest in the first year (127.7 children affected per 1000) and second year (90.8) of life, and gastroenteritis was rare after six years of age. Children from urban areas had gastroenteritis more commonly than children from semirural areas. A potential pathogen was isolated from half of the specimens: 78% were viruses, and ...

  20. Population Characteristics in Forensic Genetics

    OpenAIRE

    Faltus, Václav

    2007-01-01

    The aim of this paper is to present some methods used in forensic genetics. Forensic genetics is only one part of a wide spectrum of sciences called forensics. It includes identification of victims of natural disasters, mass transportation accidents and industry accidents. It also includes identification of offenders of a crime and determination of paternity. Our current work involves analysis of the genetic data from the Czech population. Therefore and in concordance with other international...

  1. Macroeconomic Populism in Latin America

    OpenAIRE

    Rudiger Dornbusch; Sebastian Edwards

    1989-01-01

    Macroeconomic populism is an approach to economics that emphasizes growth and income distribution and deemphasizes the risks of inflation and deficit finance, external constraints and the reaction of economic agents to aggressive non-market policies. The purpose of our paper is to show that policy experiences in different countries and periods share common features, from the initial conditions, the motivation for policies, the argument that the country's conditions are different, to the ultim...

  2. Population dynamics of bacterial persistence

    OpenAIRE

    Patra, Pintu

    2014-01-01

    The life of microorganisms is characterized by two main tasks, rapid growth under conditions permitting growth and survival under stressful conditions. The environments, in which microorganisms dwell, vary in space and time. The microorganisms innovate diverse strategies to readily adapt to the regularly fluctuating environments. Phenotypic heterogeneity is one such strategy, where an isogenic population splits into subpopulations that respond differently under identical environments. Bacteri...

  3. Understanding Adaptation in Large Populations

    OpenAIRE

    Talia Karasov; Messer, Philipp W.; Petrov, Dmitri A.

    2010-01-01

    Adaptation in eukaryotes is generally assumed to be mutation-limited because of small effective population sizes. This view is difficult to reconcile, however, with the observation that adaptation to anthropogenic changes, such as the introduction of pesticides, can occur very rapidly. Here we investigate adaptation at a key insecticide resistance locus (Ace) in Drosophila melanogaster and show that multiple simple and complex resistance alleles evolved quickly and repeatedly within individua...

  4. Population Synthesis for Mira Variables

    Institute of Scientific and Technical Information of China (English)

    Chun-Hua Zhu; Chao-Zheng Zha

    2005-01-01

    By means of a population synthesis code, we investigate the Mira variables. Their birth rate (over 0.65yr-1) and their number (~ 130000) in the Galaxy are estimated. For all possible Mira variables, ranges of their initial masses,pulsating periods, mass losses and lifetimes are given. We check our model with the observed Mira variables near the Sun and our results prove to be valid.

  5. Studying tactile sensitivity - population approach

    OpenAIRE

    Kozłowska, Agnieszka

    1998-01-01

    The purpose of this study was to investigate the basic characteristics of threshold tactile sensitivity in man. The study involved the examination of over 1500 people aged from 7 to 85 years, including 300 adult subjects aged over 21 years. 55% of the population under study were females. Digital pulps of the subjects were examined with the Semmes-Weinstein monofilaments aesthesiometer. The variability range of touch sensation was determined and the mean value and standard deviatio...

  6. The population question in Brazil.

    Science.gov (United States)

    1992-01-01

    Population control programs were instituted in Brazil in the 1960s and resulted in as 50% reduction of the fertility rate in 20 years with a reduction in population growth from 2.9%/year in the 1960s to 2.1% in the 1980s. The rapid urbanization which has occurred in Brazil also contributed to this process. While the Brazilian government has eschewed foreign intervention, it encourages the population control programs which are funded by international agencies. The women's movement became involved in policies relating to reproductive rights in 1980, and attempts were made to change the focus of women's health care and the right of women to make reproductive choices. 71% of Brazilian women of reproductive age who are married or living in consensual union use contraception. This compares with 70% of women in developed countries. In Brazil, however, 44% of the women have been sterilized, 41% use oral contraceptives (OCs), and 12% use natural or barrier methods, compared to 7, 13, and 41%, respectively, in developed countries. Sterilization is illegal in Brazil, although it is widespread; the high number of Cesarean section births may determine a medical need for sterilization (after three such deliveries, for example). Abortion is also illegal (except in cases of rape or if the mother's life is in danger) and widespread. The 2 to 3 million abortions each year are thought to be the third cause of maternal mortality. Studies of OC use have shown that Brazilian women often use OCs without medical monitoring or in cases when the contraceptive is absolutely contraindicated. In the past few years, Brazilian women's groups have demanded that the government deal with the issue of family planning in order to stop the intervention of international population control agencies. Brazil has never had the sufficiently modern and effective policy to help women to use contraception safely during the various stages of their reproductive lives. PMID:12286343

  7. Metallicity dependence of HMXB populations

    CERN Document Server

    Douna, V M; Mirabel, I F; Pedrosa, S E

    2015-01-01

    High-mass X-ray binaries (HMXBs) might have contributed a non-negligible fraction of the energy feedback to the interstellar and intergalactic media at high redshift, becoming important sources for the heating and ionization history of the Universe. However, the importance of this contribution depends on the hypothesized increase in the number of HMXBs formed in low-metallicity galaxies and in their luminosities. In this work we test the aforementioned hypothesis, and quantify the metallicity dependence of HMXB population properties. We compile from the literature a large set of data on the sizes and X-ray luminosities of HMXB populations in nearby galaxies with known metallicities and star formation rates. We use Bayesian inference to fit simple Monte Carlo models that describe the metallicity dependence of the size and luminosity of the HMXB populations. We find that HMXBs are typically ten times more numerous per unit star formation rate in low-metallicity galaxies (12 + log(O/H) < 8, namely < 20% so...

  8. Fish populations in Plynlimon streams

    Directory of Open Access Journals (Sweden)

    D. T. Crisp

    1997-01-01

    Full Text Available In Plynlimon streams, brown trout (Salmo trutta L. are widespread in the upper Wye at population densities of 0.03 to 0.32 fish m-2 and show evidence of successful recruitment in most years. In the upper Severn, brown trout are found only in an area of c. 1670 -2 downstream of Blaenhafren Falls at densities of 0.03 to 0.24 fish -2 and the evidence suggests very variable year to year success in recruitment (Crisp & Beaumont, 1996. Analyses of the data show that temperature differences between afforested and unafforested streams may affect the rates of trout incubation and growth but are not likely to influence species survival. Simple analyses of stream discharge data suggest, but do not prove, that good years for recruitment in the Hafren population were years of low stream discharge. This may be linked to groundwater inputs detected in other studies in this stream. More research is needed to explain the survival of the apparently isolated trout population in the Hafren.

  9. Population policy and family planning.

    Science.gov (United States)

    1977-01-01

    The secret of success of India's population policy is the multipronged approach. Conflicts between public beliefs, customs, and public interests in regard to family size must be resolved through effective educational measures. The state should avoid legal compulsion and rely on volumtary choice by married couples influenced by logical judgment, information, and persuasion. Instead of using coercion, research in specific regions, sub-regions, and local areas should assess feasibility in light of knowledge, attitude, and practice of birth control, and rational goals should be set. Health conditions, particularly of mother and child, are an important approach to fertility and family size. As long as the morbidity of infants is high, the motivation for small family size will be low. Women's education generally should be improved. Later age at marriage also contributed to small family size. Present population policy should be expanded to include a broad-based socioeconomic approach with a social security program. Development through improved agricultural and marketing conditions will distribute the economic benefits for and improve the welfare of the most backward people. Voluntary organizations must be involved in population programs because a wholly state-sponsored program will meet with apathy and disinterest.

  10. How Population Growth Affects Linkage Disequilibrium

    OpenAIRE

    Alan R Rogers

    2014-01-01

    The “LD curve” relates the linkage disequilibrium (LD) between pairs of nucleotide sites to the distance that separates them along the chromosome. The shape of this curve reflects natural selection, admixture between populations, and the history of population size. This article derives new results about the last of these effects. When a population expands in size, the LD curve grows steeper, and this effect is especially pronounced following a bottleneck in population size. When a population ...

  11. Territoire et population de 1800 à 1890

    OpenAIRE

    2011-01-01

    Les noms des fichiers de données commencent par le préfixe TERR. Fichier Labels Territoire et Population TERR_T85.xls Territoire et Population, 1824-1837 (Départements) TERR_T86.xls Territoire et Population, 1801-1836 (Départements) TERR_T116.xls Territoire et Population, 1801-1836 (Chefs-lieux et villes) TERR_T117.xls Territoire, Population, 1800-1890 (Arrondissements)

  12. A Tale of Two Populations

    Science.gov (United States)

    2005-03-01

    VLT FLAMES Finds Hints of Helium-Richest Stars Ever Seen Summary On the basis of stellar spectra totalling more than 200 hours of effective exposure time with the 8.2-m VLT Kueyen telescope at Paranal (Chile), a team of astronomers [1] has made a surprising discovery about the stars in the giant southern globular cluster Omega Centauri. It has been known for some time that, contrary to other clusters of this type, this stellar cluster harbours two different populations of stars that still burn hydrogen in their centres. One population, accounting for one quarter of its stars, is bluer than the other. Using the FLAMES multi-object spectrograph that is particularly well suited to this kind of work, the astronomers found that the bluer stars contain more heavy elements than those of the redder population. This was exactly opposite to the expectation and they are led to the conclusion that the bluer stars have an overabundance of the light element helium of more than 50%. They are in fact the most helium rich stars ever found. But why is this so? The team suggests that this puzzle may be explained in the following way. First, a great burst of star formation took place during which all the stars of the red population were produced. As other normal stars, these stars transformed their hydrogen into helium by nuclear burning. Some of them, with masses of 10-12 times the mass of the Sun, soon thereafter exploded as supernovae, thereby enriching the interstellar medium in the globular cluster with helium. Next, the blue population stars formed from this helium-rich medium. This unexpected discovery provides important new insights into the way stars may form in larger stellar systems. PR Photo 08a/05: The Omega Centauri Globular Cluster and the Area Surveyed (DSS and ACS/HST) PR Photo 08b/05: The Double Main Sequence of Omega Centauri PR Photo 08c/05: Average Spectra of the Blue and Red Population Stars (FLAMES + VLT) PR Photo 08d/05: The Supernova Scenario Two Populations

  13. Microbial populations in contaminant plumes

    Science.gov (United States)

    Haack, Sheridan K.; Bekins, Barbara A.

    Efficient biodegradation of subsurface contaminants requires two elements: (1) microbial populations with the necessary degradative capabilities, and (2) favorable subsurface geochemical and hydrological conditions. Practical constraints on experimental design and interpretation in both the hydrogeological and microbiological sciences have resulted in limited knowledge of the interaction between hydrogeological and microbiological features of subsurface environments. These practical constraints include: (1) inconsistencies between the scales of investigation in the hydrogeological and microbiological sciences, and (2) practical limitations on the ability to accurately define microbial populations in environmental samples. However, advances in application of small-scale sampling methods and interdisciplinary approaches to site investigations are beginning to significantly improve understanding of hydrogeological and microbiological interactions. Likewise, culture-based and molecular analyses of microbial populations in subsurface contaminant plumes have revealed significant adaptation of microbial populations to plume environmental conditions. Results of recent studies suggest that variability in subsurface geochemical and hydrological conditions significantly influences subsurface microbial-community structure. Combined investigations of site conditions and microbial-community structure provide the knowledge needed to understand interactions between subsurface microbial populations, plume geochemistry, and contaminant biodegradation. La biodégradation efficace des polluants souterrains requiert deux éléments: des populations microbiennes possédant les aptitudes nécessaires à la dégradation, et des conditions géochimiques et hydrologiques souterraines favorables. Des contraintes pratiques sur la conception et l'interprétation des expériences à la fois en microbiologie et en hydrogéologie ont conduit à une connaissance limitée des interactions entre les

  14. Who fears and who welcomes population decline?

    Directory of Open Access Journals (Sweden)

    Hendrik P. Van Dalen

    2011-08-01

    Full Text Available European countries are experiencing population decline and the tacit assumption in most analyses is that the decline may have detrimental welfare effects. In this paper we use a survey among the population in the Netherlands to discover whether population decline is always met with fear. A number of results stand out: population size preferences differ by geographic proximity: at a global level the majority of respondents favors a (global population decline, but closer to home one supports a stationary population. Population decline is clearly not always met with fear: 31 percent would like the population to decline at the national level and they generally perceive decline to be accompanied by immaterial welfare gains (improvement environment as well as material welfare losses (tax increases, economic stagnation. In addition to these driving forces it appears that the attitude towards immigrants is a very strong determinant at all geographical levels: immigrants seem to be a stronger fear factor than population decline.

  15. Familial Hypercholesterolemia in Asian Populations.

    Science.gov (United States)

    Zhou, Mengge; Zhao, Dong

    2016-05-01

    Familial hypercholesterolemia (FH) is the most common autosomal disorder characterized by an elevated low-density lipoprotein-cholesterol level and a high risk of premature cardiovascular disease. In this review, we summarize information on FH studies in Asian countries, focusing on mean cholesterol level, FH frequency, diagnostic criteria, genotypes, and clinical care of FH patients in Asian populations. Compared with Western countries, most Asian countries had lower mean cholesterol levels, with a significant variation between different countries. In the limited studies reported, a frequency of 1/900 was reported in Hokuriku district, Japan in 1977 and a frequency of 1/85 among Christian Lebanese in 1979. Recently, a population study in China reported frequencies of 0.47% and 0.28%. However, the different FH frequencies reported were based on different diagnostic criteria. Of 28 publications from 16 Asian countries or regions, 14 used self-defined FH criteria. Only one specific guideline for FH was available, which was developed by Japanese scientists. Six Asian countries joined the Make Early Diagnosis to Prevent Early Deaths program in the late 1990s, and the estimated diagnosis rates of FH ranged from 3% to 10% in these countries. A more recent study explored the awareness, knowledge, and perception of FH among practitioners in Japan, Korea, and Taiwan. The study found that the correct rates of these FH-related questions were low and concluded that lack of country-specific criteria and guidelines may contribute to the lack of FH knowledge in the present survey. More attention and resources should be focused on raising awareness, improving care, and increasing FH research in Asian populations. PMID:27075771

  16. Population genetics and cryptic species

    International Nuclear Information System (INIS)

    Does the definition of a species matter for pest management purposes? Taxonomists provide us with tools - usually morphological characters - to identify a group of organisms that we call a species. The implication of this identification is that all of the individuals that fit the provided description are members of the species in question. The taxonomists have considered the range of variation among individuals in defining the species, but this variation is often forgotten when we take the concept of species to the level of management. Just as there is morphological variation among individuals, there is also variation in practically any character we might imagine, which has implications for the short and long term success of our management tactics. The rich literature on insecticide resistance should be a constant reminder of the fact that the pressure on pest survival and reproduction applied by our management approaches frequently leads to evolutionary changes within the pest species. The degree of variation within a particular species is a defining characteristic of that species. This level of variability may have very important implications for successful management, so it is very important to measure variation and, whenever possible, the genetic basis of that variation, in a target species. Population genetic approaches can provide evidence of genetic structure (or lack thereof) among populations of a species. These types of data can be used to discuss the movement of pest populations on a local or global scale. In other cases, we may have a complex of species that share some, but not all, characteristics. Species complexes that share morphological characters (i.e., cannot be easily distinguished) but not biological characters are referred to as sibling or cryptic species

  17. Measuring happiness in large population

    Science.gov (United States)

    Wenas, Annabelle; Sjahputri, Smita; Takwin, Bagus; Primaldhi, Alfindra; Muhamad, Roby

    2016-01-01

    The ability to know emotional states for large number of people is important, for example, to ensure the effectiveness of public policies. In this study, we propose a measure of happiness that can be used in large scale population that is based on the analysis of Indonesian language lexicons. Here, we incorporate human assessment of Indonesian words, then quantify happiness on large-scale of texts gathered from twitter conversations. We used two psychological constructs to measure happiness: valence and arousal. We found that Indonesian words have tendency towards positive emotions. We also identified several happiness patterns during days of the week, hours of the day, and selected conversation topics.

  18. New Models for Population Protocols

    CERN Document Server

    Michail, Othon

    2010-01-01

    Wireless sensor networks are about to be part of everyday life. Homes and workplaces capable of self-controlling and adapting air-conditioning for different temperature and humidity levels, sleepless forests ready to detect and react in case of a fire, vehicles able to avoid sudden obstacles or possibly able to self-organize routes to avoid congestion, and so on, will probably be commonplace in the very near future. Mobility plays a central role in such systems and so does passive mobility, that is, mobility of the network stemming from the environment itself. The population protocol model was

  19. Nonlinear dynamics of interacting populations

    CERN Document Server

    Bazykin, Alexander D

    1998-01-01

    This book contains a systematic study of ecological communities of two or three interacting populations. Starting from the Lotka-Volterra system, various regulating factors are considered, such as rates of birth and death, predation and competition. The different factors can have a stabilizing or a destabilizing effect on the community, and their interplay leads to increasingly complicated behavior. Studying and understanding this path to greater dynamical complexity of ecological systems constitutes the backbone of this book. On the mathematical side, the tool of choice is the qualitative the

  20. Blurred edges to population policies.

    Science.gov (United States)

    David, H P

    1992-05-01

    Fertility is now below replacement level in most European countries, especially the industrialized ones. In the last 20 years, several countries have developed or improved pronatalist programs containing incentives that are designed to motivate couples to have a 2nd and especially a 3rd child, to maintain a stable population. The WHO Sexuality and Family Planning Unit called a short consultation on this subject last October. What actually constitutes a pronatalist population program and the connections between public policies and private reproductive behavior were not very clear. Nor is it easy to assess the longer--term demographic effects of pronatalist policies or what influences their effectiveness. The outcome usually reflects the country's history, cultural and religious traditions, changes in lifestyle, and the value given to the family and children. Incentives are defined as monetary or nonmonetary inducements to voluntary reproductive behavior that conforms to specified population policies. They may be small or large, in cash or kind, parity-specific or income-linked, immediate or developed, one-time or incremental, or any combination of these. Disincentives are negative sanctions that are either incurred or thought likely as a result of violating the policy. But both incentives and disincentives are difficult to define. Pronatalist policies designed to encourage early marriage and larger families, thereby raising the future total fertility rate should not be confused with traditional social welfare policies designed simply to ease the burden of childbearing. Some policies have both demographic and social welfare aims. Strong pronatalist policies may be linked with restrictions on contraceptive availability and legal abortion. Moreover, other public policies affecting social security, education, employment, housing, regional planning and the emancipation of women may unintentionally influence demographic behavior. Population policies are the product of

  1. GDP growth rate and population

    OpenAIRE

    Kitov, Ivan O.

    2005-01-01

    Real GDP growth rate in developed countries is found to be a sum of two terms. The first term is the reciprocal value of the duration of the period of mean income growth with work experience, Tcr. The current value of Tcr in the USA is 40 years. The second term is inherently related to population and defined by the relative change in the number of people with a specific age (9 years in the USA), (1/2)*dN9(t) /N9(t), where N9(t) is the number of 9-year-olds at time t. The Tcr grows as the squa...

  2. Paraguay: population and the economy.

    Science.gov (United States)

    Sanders, T G

    1986-01-01

    Paraguay's political conflicts and development experiences have been accompanied by compensatory population movements; however, economic and population policies of the past are not adequate to address the current economic challenges. The principal structural problem is dependence on international commodity prices. Since late 1984, the international prices for soya and cotton have declined more than 50%; these 2 products account for 83% of official exports. The external debt has grown significantly in the past 5 years and is increasingly difficult to service. A major problem the government faces in servicing the debt and maintaining economic growth is its inability to get control of foreign exchange. Much of Paraguay's external trade is contraband, with the dollars passing into the black market. As a result of the illegal economy, government earnings have been insufficient to cover expenses. Unemployment stands at 12% because of general economic decline, cuts in government expenditure, and the reduction of investment in hydroelectricity. Occupation of new land, the classic solution by the Paraguayan peasantry, is no longer a viable option since all land is now utilized. About 20-25% of Paraguayans live outside the country, expecially in Argentina. In 1986, a commission drafted an Adjustment Plan that recommended a devaluation of the official gurani rate, tax increases, higher tariffs for public services, and incentives to invest in priority areas; however, this plan has not been implemented to date. PMID:12315094

  3. Modelling nova populations in galaxies

    CERN Document Server

    Chen, Hai-Liang; Yungelson, L R; Gilfanov, M; Han, Zhanwen

    2016-01-01

    Theoretical modelling of the evolution of classical and recurrent novae plays an important role in studies of binary evolution, nucleosynthesis and accretion physics. However, from a theoretical perspective the observed statistical properties of novae remain poorly understood. In this paper, we have produced model populations of novae using a hybrid binary population synthesis approach for differing star formation histories (SFHs): a starburst case (elliptical-like galaxies), a constant star formation rate case (spiral-like galaxies) and a composite case (in line with the inferred SFH for M31). We found that the nova rate at 10\\;Gyr in an elliptical-like galaxy is $\\sim 10-20$ times smaller than a spiral-like galaxy with the same mass. The majority of novae in elliptical-like galaxies at the present epoch are characterized by low mass white dwarfs (WDs), long decay times, relatively faint absolute magnitudes and long recurrence periods. In contrast, the majority of novae in spiral-like galaxies at 10\\;Gyr hav...

  4. Direct reciprocity in structured populations.

    Science.gov (United States)

    van Veelen, Matthijs; García, Julián; Rand, David G; Nowak, Martin A

    2012-06-19

    Reciprocity and repeated games have been at the center of attention when studying the evolution of human cooperation. Direct reciprocity is considered to be a powerful mechanism for the evolution of cooperation, and it is generally assumed that it can lead to high levels of cooperation. Here we explore an open-ended, infinite strategy space, where every strategy that can be encoded by a finite state automaton is a possible mutant. Surprisingly, we find that direct reciprocity alone does not lead to high levels of cooperation. Instead we observe perpetual oscillations between cooperation and defection, with defection being substantially more frequent than cooperation. The reason for this is that "indirect invasions" remove equilibrium strategies: every strategy has neutral mutants, which in turn can be invaded by other strategies. However, reciprocity is not the only way to promote cooperation. Another mechanism for the evolution of cooperation, which has received as much attention, is assortment because of population structure. Here we develop a theory that allows us to study the synergistic interaction between direct reciprocity and assortment. This framework is particularly well suited for understanding human interactions, which are typically repeated and occur in relatively fluid but not unstructured populations. We show that if repeated games are combined with only a small amount of assortment, then natural selection favors the behavior typically observed among humans: high levels of cooperation implemented using conditional strategies.

  5. Hypernatremia in the geriatric population

    Directory of Open Access Journals (Sweden)

    Shah MK

    2014-11-01

    Full Text Available Maulin K Shah,1 Biruh Workeneh,1,2 George E Taffet1,3 1Department of Internal Medicine, 2Department of Nephrology, 3Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA Abstract: Hypernatremia in the geriatric population is a common disorder associated with significant morbidity and mortality. Older people are predisposed to developing hypernatremia because of age-related physiologic changes such as decreased thirst drive, impaired urinary concentrating ability, and reduced total body water. Medications may exacerbate this predisposition. Hypernatremia and dehydration occurring in nursing homes are considered indicators of neglect that warrant reporting, but there are other nonavoidable causes of hypernatremia, and consideration at time of presentation is essential to prevent delay in diagnosis and management. We describe a case illustrating the importance of the consideration of alternate explanations for hypernatremia in a nursing home resident, followed by a review of hypernatremia in the elderly population, to underscore that neglect is the etiology of exclusion after alternatives have been considered. Keywords: geriatric, hypernatremia, sodium

  6. Social exclusion in finite populations

    Science.gov (United States)

    Li, Kun; Cong, Rui; Wu, Te; Wang, Long

    2015-04-01

    Social exclusion, keeping free riders from benefit sharing, plays an important role in sustaining cooperation in our world. Here we propose two different exclusion regimes, namely, peer exclusion and pool exclusion, to investigate the evolution of social exclusion in finite populations. In the peer exclusion regime, each excluder expels all the defectors independently, and thus bears the total cost on his own, while in the pool exclusion regime, excluders spontaneously form an institution to carry out rejection of the free riders, and each excluder shares the cost equally. In a public goods game containing only excluders and defectors, it is found that peer excluders outperform pool excluders if the exclusion costs are small, and the situation is converse once the exclusion costs exceed some critical points, which holds true for all the selection intensities and different update rules. Moreover, excluders can dominate the whole population under a suitable parameters range in the presence of second-order free riders (cooperators), showing that exclusion has prominent advantages over common costly punishment. More importantly, our finding indicates that the group exclusion mechanism helps the cooperative union to survive under unfavorable conditions. Our results may give some insights into better understanding the prevalence of such a strategy in the real world and its significance in sustaining cooperation.

  7. Bioethics, population studies, and geneticophobia.

    Science.gov (United States)

    Salzano, Francisco M

    2015-07-01

    In any research of human populations, the classical principles of bioethics (respect for autonomy, non-maleficence, beneficence, proportionality between risks and benefits, and justice) should be strictly followed. The question of individual and/or community rights should also be considered, as well as some neglected rights, such as the right to benefit from progress in science and technology and the right to know the nature of the group's biological and cultural history; however, in their urge to assure rights, social researchers, bioethics commissions, non-governmental organizations, and community leaders are, in many cases, crossing the limits of good sense. DNA is sometimes interpreted as synonymous to demoniac, and there is a frequent behaviour that I could only describe using a neologism: geneticophobia. There is an irrational attitude against genetic studies aiming to unravel the biological history of a given people and to classify any genome population study as "racist". This behaviour should be opposed; science and the scientific study of humankind are the only way we have to reach the socially adequate objective of the maximum of happiness to the largest number of persons. PMID:25575494

  8. Reconstructing Native American Population History

    Science.gov (United States)

    Reich, David; Patterson, Nick; Campbell, Desmond; Tandon, Arti; Mazieres, Stéphane; Ray, Nicolas; Parra, Maria V.; Rojas, Winston; Duque, Constanza; Mesa, Natalia; García, Luis F.; Triana, Omar; Blair, Silvia; Maestre, Amanda; Dib, Juan C.; Bravi, Claudio M.; Bailliet, Graciela; Corach, Daniel; Hünemeier, Tábita; Bortolini, Maria-Cátira; Salzano, Francisco M.; Petzl-Erler, María Luiza; Acuña-Alonzo, Victor; Aguilar-Salinas, Carlos; Canizales-Quinteros, Samuel; Tusié-Luna, Teresa; Riba, Laura; Rodríguez-Cruz, Maricela; Lopez-Alarcón, Mardia; Coral-Vazquez, Ramón; Canto-Cetina, Thelma; Silva-Zolezzi, Irma; Fernandez-Lopez, Juan Carlos; Contreras, Alejandra V.; Jimenez-Sanchez, Gerardo; Gómez-Vázquez, María José; Molina, Julio; Carracedo, Ángel; Salas, Antonio; Gallo, Carla; Poletti, Giovanni; Witonsky, David B.; Alkorta-Aranburu, Gorka; Sukernik, Rem I.; Osipova, Ludmila; Fedorova, Sardana; Vasquez, René; Villena, Mercedes; Moreau, Claudia; Barrantes, Ramiro; Pauls, David; Excoffier, Laurent; Bedoya, Gabriel; Rothhammer, Francisco; Dugoujon, Jean Michel; Larrouy, Georges; Klitz, William; Labuda, Damian; Kidd, Judith; Kidd, Kenneth; Rienzo, Anna Di; Freimer, Nelson B.; Price, Alkes L.; Ruiz-Linares, Andrés

    2013-01-01

    The peopling of the Americas has been the subject of extensive genetic, archaeological and linguistic research; however, central questions remain unresolved1–5. One contentious issue is whether the settlement occurred via a single6–8 or multiple streams of migration from Siberia9–15. The pattern of dispersals within the Americas is also poorly understood. To address these questions at higher resolution than was previously possible, we assembled data from 52 Native American and 17 Siberian groups genotyped at 364,470 single nucleotide polymorphisms. We show that Native Americans descend from at least three streams of Asian gene flow. Most descend entirely from a single ancestral population that we call “First American”. However, speakers of Eskimo-Aleut languages from the Arctic inherit almost half their ancestry from a second stream of Asian gene flow, and the Na-Dene-speaking Chipewyan from Canada inherit roughly one-tenth of their ancestry from a third stream. We show that the initial peopling followed a southward expansion facilitated by the coast, with sequential population splits and little gene flow after divergence, especially in South America. A major exception is in Chibchan-speakers on both sides of the Panama Isthmus, who have ancestry from both North and South America. PMID:22801491

  9. Mapping population and pathogen movements.

    Science.gov (United States)

    Tatem, Andrew J

    2014-03-01

    For most of human history, populations have been relatively isolated from each other, and only recently has there been extensive contact between peoples, flora and fauna from both old and new worlds. The reach, volume and speed of modern travel are unprecedented, with human mobility increasing in high income countries by over 1000-fold since 1800. This growth is putting people at risk from the emergence of new strains of familiar diseases, and from completely new diseases, while ever more cases of the movement of both disease vectors and the diseases they carry are being seen. Pathogens and their vectors can now move further, faster and in greater numbers than ever before. Equally however, we now have access to the most detailed and comprehensive datasets on human mobility and pathogen distributions ever assembled, in order to combat these threats. This short review paper provides an overview of these datasets, with a particular focus on low income regions, and covers briefly approaches used to combine them to help us understand and control some of the negative effects of population and pathogen movements. PMID:24480992

  10. Population screening in hereditary hemochromatosis.

    Science.gov (United States)

    Motulsky, A G; Beutler, E

    2000-01-01

    Hemochromatosis is a common autosomal recessive condition found in the homozygous state in 1/200-1/400 people of northern-, central-, and western-European origin. It causes increased iron storage, which may lead to liver cirrhosis, liver cancer, heart disease, arthritis, and diabetes in many but not all affected adults, with a higher frequency in males. The condition is easily treated by repeated venesections without side effects but is frequently overlooked. Population screening of adults using iron indices alone or combined with DNA testing has therefore been recommended, but a consensus conference in 1997 recommended that such screening be deferred, owing to uncertainty regarding the extent of clinical disease that may develop in individuals detected by such programs. There was also concern that DNA screening results might be used for discrimination in insurance and occupational settings. Screening family members of patients with evidence of definite iron loading, however, is accepted by all observers. Because serious complications may be overlooked, a more aggressive stance toward case detection in the adult population has been advocated by some observers, realizing that unnecessary treatment might occur. Because additional information regarding the spectrum of clinical disease in homozygotes in now accumulating, a consensus conference in the near future is suggested to consider appropriate policies.

  11. Population change and educational development.

    Science.gov (United States)

    Jayasuriya, J E

    1982-06-01

    The 4 principal conditions of a stable society are: 1) minimum disruption of ecological processes, 2) maximum conservation of material and energy or an economy of stock rather than flow, 3) a population in which recruitment equals loss, and 4) a social system in which individuals can enjoy rather than be restricted by the 1st 3 conditions. In 1960 the developing countries set goals relating to education including the achievement of universal primary education, the eradication of illiteracy, and the provision of secondary and tertiary education to meet manpower needs. The countries with the highest enrollment ratios in 1980 were Korea, 100%, Singapore, 100%, Malaysia, 94%, Philippines 80.6%, Thailand, 77.8%, and Iran 75.5%. Eradication of illiteracy has not been reached since by 1990 Afghanistan, India, Nepal, and Pakistan will have illiteracy rates of over 50% and as a result of increases in the absolute number of illiterates over the period of 1970-90 in Afghanistan, Bangladesh, India, Nepal, and Pakistan, the number of illiterates in the developing countries of Asia will increase from 339.1 million in 1970 to 425.6 million in 1990. The females and rural population are especially disadvantaged groups in terms of education; 98.4% of rural females are illiterate as compared to 63.8% of urban males and in Iran 91.7% of rural females compared with 31.3% of urban males are illiterate. One reason for shortfalls in the achievement of educational goals is rapid population growth, especially of school-age groups; for instance the total population aged 6-11 in Indonesia increased by 89.3%. In a study on the Philippines conducted in 1975 it was found that, for the series of high projections, the schedule of age-specific fertility rates observed for 1968-72 resulting in a total fertility rate of 5.89 would remain constant throughout the projection period, the death rate would decline by 4.8 points, international migration would remain negligible; for the low projections

  12. PN populations in the local group and distant stellar populations

    Science.gov (United States)

    Reid, Warren

    2016-08-01

    Our understanding of galactic structure and evolution is far from complete. Within the past twelve months we have learnt that the Milky Way is about 50% wider than was previously thought. As a consequence, new models are being developed that force us to reassess the kinematic structure of our Galaxy. Similarly, we need to take a fresh look at the halo structure of external galaxies in our Local Group. Studies of stellar populations, star-forming regions, clusters, the interstellar medium, elemental abundances and late stellar evolution are all required in order to understand how galactic assembly has occurred as we see it. PNe play an important role in this investigation by providing a measure of stellar age, mass, abundances, morphology, kinematics and synthesized matter that is returned to the interstellar medium (ISM). Through a method of chemical tagging, halo PNe can reveal evidence of stellar migration and galactic mergers. This is an outline of the advances that have been made towards uncovering the full number of PNe in our Local Group galaxies and beyond. Current numbers are presented and compared to total population estimates based on galactic mass and luminosity. A near complete census of PNe is crucial to understanding the initial-to-final mass relation for stars with mass >1 to mass of the sun. It also allows us to extract more evolutionary information from luminosity functions and compare dust-to-gas ratios from PNe in different galactic locations. With new data provided by the Gaia satellite, space-based telescopes and the rise of giant and extra-large telescopes, we are on the verge of observing and understanding objects such as PNe in distant galaxies with the same detail we expected from Galactic observations only a decade ago.

  13. PN populations in the local group and distant stellar populations

    Science.gov (United States)

    Reid, Warren

    2016-08-01

    Our understanding of galactic structure and evolution is far from complete. Within the past twelve months we have learnt that the Milky Way is about 50% wider than was previously thought. As a consequence, new models are being developed that force us to reassess the kinematic structure of our Galaxy. Similarly, we need to take a fresh look at the halo structure of external galaxies in our Local Group. Studies of stellar populations, star-forming regions, clusters, the interstellar medium, elemental abundances and late stellar evolution are all required in order to understand how galactic assembly has occurred as we see it. PNe play an important role in this investigation by providing a measure of stellar age, mass, abundances, morphology, kinematics and synthesized matter that is returned to the interstellar medium (ISM). Through a method of chemical tagging, halo PNe can reveal evidence of stellar migration and galactic mergers. This is an outline of the advances that have been made towards uncovering the full number of PNe in our Local Group galaxies and beyond. Current numbers are presented and compared to total population estimates based on galactic mass and luminosity. A near complete census of PNe is crucial to understanding the initial-to-final mass relation for stars with mass >1 to information from luminosity functions and compare dust-to-gas ratios from PNe in different galactic locations. With new data provided by the Gaia satellite, space-based telescopes and the rise of giant and extra-large telescopes, we are on the verge of observing and understanding objects such as PNe in distant galaxies with the same detail we expected from Galactic observations only a decade ago.

  14. Population momentum across vertebrate life histories

    Science.gov (United States)

    Koons, D.N.; Grand, J.B.; Arnold, J.M.

    2006-01-01

    Population abundance is critically important in conservation, management, and demographic theory. Thus, to better understand how perturbations to the life history affect long-term population size, we examined population momentum for four vertebrate classes with different life history strategies. In a series of demographic experiments we show that population momentum generally has a larger effect on long-term population size for organisms with long generation times than for organisms with short generation times. However, patterns between population momentum and generation time varied across taxonomic groups and according to the life history parameter that was changed. Our findings indicate that momentum may be an especially important aspect of population dynamics for long-lived vertebrates, and deserves greater attention in life history studies. Further, we discuss the importance of population momentum in natural resource management, pest control, and conservation arenas. ?? 2006 Elsevier B.V. All rights reserved.

  15. [Demographic processes and world population numbers].

    Science.gov (United States)

    Donkov, K

    1986-01-01

    Recent global population trends are reviewed. The author notes the growing divergence in demographic trends between the developed and developing regions. These differences are analyzed in the light of Marxist population theory. (SUMMARY IN ENG AND RUS) PMID:12280530

  16. Mutational meltdown in laboratory yeast populations

    NARCIS (Netherlands)

    Zeyl, C.; Mizesko, M.; Visser, de J.A.G.M.

    2001-01-01

    In small or repeatedly bottlenecked populations, mutations are expected to accumulate by genetic drift, causing fitness declines. In mutational meltdown models, such fitness declines further reduce population size, thus accelerating additional mutation accumulation and leading to extinction. Because

  17. Measuring populations to improve vaccination coverage

    Science.gov (United States)

    Bharti, Nita; Djibo, Ali; Tatem, Andrew J.; Grenfell, Bryan T.; Ferrari, Matthew J.

    2016-01-01

    In low-income settings, vaccination campaigns supplement routine immunization but often fail to achieve coverage goals due to uncertainty about target population size and distribution. Accurate, updated estimates of target populations are rare but critical; short-term fluctuations can greatly impact population size and susceptibility. We use satellite imagery to quantify population fluctuations and the coverage achieved by a measles outbreak response vaccination campaign in urban Niger and compare campaign estimates to measurements from a post-campaign survey. Vaccine coverage was overestimated because the campaign underestimated resident numbers and seasonal migration further increased the target population. We combine satellite-derived measurements of fluctuations in population distribution with high-resolution measles case reports to develop a dynamic model that illustrates the potential improvement in vaccination campaign coverage if planners account for predictable population fluctuations. Satellite imagery can improve retrospective estimates of vaccination campaign impact and future campaign planning by synchronizing interventions with predictable population fluxes. PMID:27703191

  18. Five Facts about the Uninsured Population

    Science.gov (United States)

    ... unui tthhee nnsinusreudred Five Facts About the Uninsured Population September 2012 Nearly 48 million nonelderly Americans were ... 5 Key Details:  The share of the nonelderly population with employer-sponsored coverage declined steadily between 2000 ...

  19. Competition-density effect in plant populations

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The competition-density effect of plant populations is of significance in theory and practice of forest management and has been studied for long time. The differences between the two reciprocal equations of the competition-density effect in nonself-thinning populations and self-thinning populations were analyzed theoretically. This supplies a theoretical basis for analyzing the dynamics of forest populations and evaluating the effect of forest management.

  20. Constant global population with demographic heterogeneity

    OpenAIRE

    Cohen, Joel E.

    2008-01-01

    To understand better a possible future constant global population that is demographically heterogeneous, this paper analyzes several models. Classical theory of stationary populations generally fails to apply. However, if constant global population size P(global) is the sum of all country population sizes, and if constant global annual number of births B(global) is the sum of the annual number of births of all countries, and if constant global life expectancy at birth e(global) is the populat...

  1. Research on Population Prediction of Guizhou Province

    Institute of Scientific and Technical Information of China (English)

    Shuang; YU; Guang; LI

    2013-01-01

    In accordance with population development of Guizhou Province in 1977-2007,this paper adopts natural growth method,model prediction method and gray system GM (1,1) model prediction method to predict population of Guizhou Province in 2020. On the basis of overall consideration of many factors of population development and future development trend of Guizhou Province,it analyzes advantages and disadvantages of three prediction methods,and obtains the prediction value of total population of Guizhou Province in 2020.

  2. Population communication management training strategy.

    Science.gov (United States)

    Bayan Salas, E

    1985-01-01

    The discussion presents some thoughts on a general training strategy in information/education/communication (IEC) management which might meet the needs of 3rd world countries. Management by objectives (MBO) has emerged as the central doctrine in management theory and practice since its initial formulation in 1954. Yet, little evidence exists to date of its successful application in IEC activities. Population IEC activities, being staff activities in a nonprofit, public sector program, are in the "twilight zone" of MBO where hasty efforts to comply with the form if not the substance of this management technique can lead to lower levels of performance and achievement than before the goal setting system was implemented. Yet, clearly, IEC managers need the benefits that management by objectives can bring if done properly. It is essential that IEC managers and workers stop looking at IEC materials as end products in themselves but rather as inputs to be combined with other inputs in realizing the desired output of voluntary behavioral change on a mass level. To overcome tendencies toward provincialism, all IEC managers should initially spend time working in other areas of the population program. The experience of using IEC materials and approaches in face-to-face transactions with potential acceptors is a prerequisite to the successful formulation of such materials and approaches. Training programs for IEC managers and supervisors should emphasize development of consensual decision making skills. The success or failure of the program depends on the ability of its workers to resolve potential conflicts between an individual's priorities and national priorities in a noncoercive manner. The social dynamics approach that seeks a conscious, voluntary, nonmanipulated shift of shared attitudes, opinions, feelings, and actions is the approach underlying the most successful population programs. All IEC managers and supervisors should be systematically trained in norm shifting

  3. Evolution in Stage-Structured Populations

    Science.gov (United States)

    Barfield, Michael; Holt, Robert D.; Gomulkiewicz, Richard

    2016-01-01

    For many organisms, stage is a better predictor of demographic rates than age. Yet no general theoretical framework exists for understanding or predicting evolution in stage-structured populations. Here, we provide a general modeling approach that can be used to predict evolution and demography of stage-structured populations. This advances our ability to understand evolution in stage-structured populations to a level previously available only for populations structured by age. We use this framework to provide the first rigorous proof that Lande’s theorem, which relates adaptive evolution to population growth, applies to stage-classified populations, assuming only normality and that evolution is slow relative to population dynamics. We extend this theorem to allow for different means or variances among stages. Our next major result is the formulation of Price’s theorem, a fundamental law of evolution, for stage-structured populations. In addition, we use data from Trillium grandiflorum to demonstrate how our models can be applied to a real-world population and thereby show their practical potential to generate accurate projections of evolutionary and population dynamics. Finally, we use our framework to compare rates of evolution in age- versus stage-structured populations, which shows how our methods can yield biological insights about evolution in stage-structured populations. PMID:21460563

  4. Is Populism a Thing of the Past?

    NARCIS (Netherlands)

    Wolffram, Dirk Jan

    2012-01-01

    Is Populism a Thing of the Past? Is populism a category that contributes to our understanding of politics and its history? A large number of books are dedicated to populism and new titles are published weekly. In this article the balance is drawn up by judging books with different scientific pretent

  5. [Mathematical model of value of population].

    Science.gov (United States)

    Sha, J; Wang, S

    1983-09-29

    The authors define the value of population as an economic concept and present mathematical formulas for calculating this value. Included in this theoretical discussion are different kinds of surplus value of population and the social significance of population value. PMID:12279805

  6. 45 CFR 1356.81 - Reporting population.

    Science.gov (United States)

    2010-10-01

    ... care as defined in 45 CFR 1355.20 and reaches his or her 17th birthday during Federal fiscal year (FFY... 45 Public Welfare 4 2010-10-01 2010-10-01 false Reporting population. 1356.81 Section 1356.81... § 1356.81 Reporting population. The reporting population is comprised of all youth in the...

  7. China Faces Nine Obstacles in Population Development

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    With drastic changes in both the international and domestic environment for population and family planning development, China faces nine major challenges in its efforts to further its population and family planning program, said Zhang Weiqing,Minister of the National Population and Family

  8. Time to extinction of bird populations

    NARCIS (Netherlands)

    Sæther, B-E.; Engen, S.; Møller, A.P.; Visser, M.E.; Matthysen, E.; Fiedler, W.; Lambrechts, M.M.; Becker, P.H.; Brommer, J.E.; Dickinson, J.; du Feu, C.; Gehlbach, F.R.; Merilä, J.; Rendell, W.; Robertson, R.J.; Thomson, D.L.; Török, J.

    2005-01-01

    The risk of extinction of populations has not previously been empirically related to parameters characterizing their population dynamics. To analyze this relationship, we simulated how the distribution of population dynamical characters changed as a function of time, in both the remaining and the ex

  9. Dissociation Patterns in Evolving Populations

    Science.gov (United States)

    Moreno, F. J.; Hernández, J. A.; Sánchez, F.

    2011-09-01

    The recent explosion and availability of mobility based technologies such as geographic information systems, cell phones equipped with built-in GPS, among others, are a valuable source of spatio-temporal data. However, only recently there have been works focused on identifying movement patterns in groups of moving entities. We focus on a particular movement pattern: dissociation. A dissociation pattern occurs when an entity that was once associated to a population, eventually separated from it and subsequently reintegrated it again. The backwarding and forwarding patterns are a type of dissociation where an entity stays behind or ahead of another entity, respectively. Dissociation really is a diversity generator, so instead avoiding it, taking advantage could be better to prevent premature convergence in evolutionary algorithms. In this work, we present formal mathematical definitions for these patterns. A discussion of how to use dissociation patterns as a mean to preserve diversity in evolutionary algorithms is also shown.

  10. The Galactic centre pulsar population

    CERN Document Server

    Chennamangalam, Jayanth

    2013-01-01

    The recent discovery of a magnetar in the Galactic centre region has allowed Spitler et al. to characterize the interstellar scattering in that direction. They find that the temporal broadening of the pulse profile of the magnetar is substantially less than that predicted by models of the electron density of that region. This raises the question of what the plausible limits for the number of potentially observable pulsars - i.e., the number of pulsars beaming towards the Earth - in the Galactic centre region are. In this paper, using realistic assumptions, we show that the potentially observable population of pulsars in the inner parsec has a conservative upper limit of $\\sim$950, and that it is premature to conclude that the number of pulsars in this region is small. We also show that the observational results so far are consistent with this number and make predictions for future radio pulsar surveys of the Galactic centre.

  11. Population Dynamics and Air Pollution

    DEFF Research Database (Denmark)

    Flachs, Esben Meulengracht; Sørensen, Jan; Bønløkke, Jacob;

    2013-01-01

    Objective. To explore how three different assumptions on demographics affect the health impact of Danish emitted air pollution in Denmark from 2005 to 2030, with health impact modeled from 2005 to 2050. Methods. Modeled air pollution from Danish sources was used as exposure in a newly developed......) a static year 2005 population, (2) morbidity and mortality fixed at the year 2005 level, or (3) an expected development. Results. The health impact of air pollution was estimated at 672,000, 290,000, and 280,000 lost life years depending on demographic assumptions and the corresponding social costs at 430.......4 M€, 317.5 M€, and 261.6 M€ through the modeled years 2005–2050. Conclusion. The modeled health impact of air pollution differed widely with the demographic assumptions, and thus demographics and assumptions on demographics played a key role in making health impact assessments on air pollution....

  12. Population Pharmacokinetics of Intranasal Scopolamine

    Science.gov (United States)

    Wu, L.; Chow, D. S. L.; Putcha, L.

    2013-01-01

    Introduction: An intranasal gel dosage formulation of scopolamine (INSCOP) was developed for the treatment of Space Motion Sickness (SMS).The bioavailability and pharmacokinetics (PK) was evaluated using data collected in Phase II IND protocols. We reported earlier statistically significant gender differences in PK parameters of INSCOP at a dose level of 0.4 mg. To identify covariates that influence PK parameters of INSCOP, we examined population covariates of INSCOP PK model for 0.4 mg dose. Methods: Plasma scopolamine concentrations versus time data were collected from 20 normal healthy human subjects (11 male/9 female) after a 0.4 mg dose. Phoenix NLME was employed for PK analysis of these data using gender, body weight and age as covariates for model selection. Model selection was based on a likelihood ratio test on the difference of criteria (-2LL). Statistical significance for base model building and individual covariate analysis was set at P less than 0.05{delta(-2LL)=3.84}. Results: A one-compartment pharmacokinetic model with first-order elimination best described INSCOP concentration ]time profiles. Inclusion of gender, body weight and age as covariates individually significantly reduced -2LL by the cut-off value of 3.84(P less than 0.05) when tested against the base model. After the forward stepwise selection and backward elimination steps, gender was selected to add to the final model which had significant influence on absorption rate constant (ka) and the volume of distribution (V) of INSCOP. Conclusion: A population pharmacokinetic model for INSCOP has been identified and gender was a significant contributing covariate for the final model. The volume of distribution and Ka were significantly higher in males than in females which confirm gender-dependent pharmacokinetics of scopolamine after administration of a 0.4 mg dose.

  13. Agricultural ponds support amphibian populations

    Science.gov (United States)

    Knutson, M.G.; Richardson, W.B.; Reineke, D.M.; Gray, B.R.; Parmelee, J.R.; Weick, S.E.

    2004-01-01

    In some agricultural regions, natural wetlands are scarce, and constructed agricultural ponds may represent important alternative breeding habitats for amphibians. Properly managed, these agricultural ponds may effectively increase the total amount of breeding habitat and help to sustain populations. We studied small, constructed agricultural ponds in southeastern Minnesota to assess their value as amphibian breeding sites. Our study examined habitat factors associated with amphibian reproduction at two spatial scales: the pond and the landscape surrounding the pond. We found that small agricultural ponds in southeastern Minnesota provided breeding habitat for at least 10 species of amphibians. Species richness and multispecies reproductive success were more closely associated with characteristics of the pond (water quality, vegetation, and predators) compared with characteristics of the surrounding landscape, but individual species were associated with both pond and landscape variables. Ponds surrounded by row crops had similar species richness and reproductive success compared with natural wetlands and ponds surrounded by nongrazed pasture. Ponds used for watering livestock had elevated concentrations of phosphorus, higher turbidity, and a trend toward reduced amphibian reproductive success. Species richness was highest in small ponds, ponds with lower total nitrogen concentrations, tiger salamanders (Ambystoma tigrinum) present, and lacking fish. Multispecies reproductive success was best in ponds with lower total nitrogen concentrations, less emergent vegetation, and lacking fish. Habitat factors associated with higher reproductive success varied among individual species. We conclude that small, constructed farm ponds, properly managed, may help sustain amphibian populations in landscapes where natural wetland habitat is rare. We recommend management actions such as limiting livestock access to the pond to improve water quality, reducing nitrogen input, and

  14. Psoriasis in the pediatric population

    International Nuclear Information System (INIS)

    A scientific and updated bibliographic review is realized for handling and care of a pediatric patient with psoriasis disease. Health personnel related with this pathology must to know the different perspectives and angles of psoriasis, as well as clinical criteria, therapeutic and emotional in the treatment of patients. The incidence of psoriasis is recognized globally. Ethnic groups have developed with most frequently this disorder. The different clinical faces of psoriasis are studied. The morphological and topographical manifestations have presented a variety very similar to that of adults, and have made for the doctor difficult to make the diagnostic. Clinical studies that were realized in the last years, have reported etiological and pathogenic evidence, both genetic and immunological of this illness. Children with psoriasis usually have presented a mild illness, where psoriasis type plaque has been the predominant variant. Psoriasis in the population has required a special attention in triggers or aggravating factors of this disease such as infections, exposure to snuff, obesity, stress and interactions with other drugs. The discovery and use of new drugs have led to different etiological factors for the handling of psoriasis; so it is important to know the function, availability and adverse effects that can to cause new therapies. Treatments must to include the provision of a safe and effective therapy for the maintenance for free long periods of lesions, reducing the severity of the disease, and inhibiting structural damage of joints. The topical treatment has been the therapy of first choice in mild psoriasis and localized. An interrogatory is recommended to decide objectively a systemic treatment, because the infant population has been a sensitive group of possible adverse effects. Methotrexate has been the treatment of choice for psoriasis related to arthropathy both adults and children. Phototherapy, including UVB, PUVA light and excimer laser is

  15. Immigration-extinction dynamics of stochastic populations

    Science.gov (United States)

    Meerson, Baruch; Ovaskainen, Otso

    2013-07-01

    How high should be the rate of immigration into a stochastic population in order to significantly reduce the probability of observing the population become extinct? Is there any relation between the population size distributions with and without immigration? Under what conditions can one justify the simple patch occupancy models, which ignore the population distribution and its dynamics in a patch, and treat a patch simply as either occupied or empty? We answer these questions by exactly solving a simple stochastic model obtained by adding a steady immigration to a variant of the Verhulst model: a prototypical model of an isolated stochastic population.

  16. Limiting factors in caribou population ecology

    Directory of Open Access Journals (Sweden)

    David R. Klein

    1991-10-01

    Full Text Available Caribou and wild reindeer populations fluctuate over time. On this fact there is general agreement. Factors responsible for population limitation and subsequent declines have been examined within the framework of animal population theory. There is, however, little agreement when factors limiting specific populations are generalized to Rangifer populations over broad geographic regions. Comparative examinations of wild Rangifer populations worldwide discloses that factors that have regulated those populations are highly variable between populations, apparently as a reflection of the differences in environmental variables unique to each population. Examples exist of populations where major regulating factors have been climatic extremes, predation, hunting mortality, food limitation, insects, parasites, disease, interspecific competition, and human developmental impacts or combinations of these factors. This diversity of limiting factors affecting caribou and wild reindeer populations is a reflection of the ecologial complexity of the species, a concept that has often been ignored in past efforts to reach management decisions by extrapolation from the limited localized knowledge available on the species.

  17. On Population Mobility in Market Economy

    Institute of Scientific and Technical Information of China (English)

    Yu Xianzhong

    2005-01-01

    Regular and extensive social population mobility in natural economy is neither necessary nor possible while in a planned economic system, social population distribution is necessary but social population mobility is unlikely. Modern market economy as a highly mobile economy has a free-mobile population characteristic of market economy, which is fundamental to optimize human resource distribution. The rule for the modern market-based population movement is as follows: If the mobile population is the rational behavior choosers, under the permissive developmental environment as arranged by the social system, they tend to move from low profit-making fields to high income fields when there exists comparable difference of income in different regions and different industries, and various potential and practical profit-making chances. The degree of difference in comparable income is positively co-relative to the velocity and flux of mobile population.

  18. Population structure and adaptation in fishes

    DEFF Research Database (Denmark)

    Limborg, Morten

    -specific population structure and adaptive divergence. The large population sizes and high migration rates common to most marine fishes impede the differentiating effect of genetic drift, having led to expectations of no population structure and that the occurrence of local adaptation should be rare in these species....... Comprehensive genetic analyses on the small pelagic fish European sprat (Sprattus sprattus) revealed significant population structure throughout its distribution with an overall pattern of reduced connectivity across environmental transition zones. Population structure reflected both historical separations over...... glacial time scales and more recent colonisation of new habitats. Further, strong genetic divergence at several regional scales demonstrated limited connectivity among sea-going and local fjord populations along the Norwegian coast as well as indications for the potential of locally adapted populations...

  19. Genetic Variation Among White Croaker Populations

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To investigate the genetic structures and differentiation of different wild populations of white croaker (Pennahia argentata), horizontal starch gel electrophoresis was performed on 133 individuals collected from five different locations in China and Japan. The eleven enzyme systems revealed 15 loci, of which eleven were polymorphic. The percentage ofpolymorphic loci of white croaker populations varied from 6.67% to 53.33%; the mean observed and expected heterozygosity ranged from 0.0033 to 0.0133and 0.0032 to 0.0191, respectively. The expected heterozygosity revealed a low genetic variability for white croaker in comparison with other marine fishes. The genetic distances between populations ranged from 0.00005 to 0.00026. A weak differentiation was observed within each clade and between clades; and no significant differences in gene frequencies among populations were observed in white croaker. Among the five populations, three Chinese populations showed more genetic diversity than that in Japanese populations.

  20. Cooperation, cheating, and collapse in biological populations

    Science.gov (United States)

    Gore, Jeff

    2014-03-01

    Natural populations can collapse suddenly in response to small changes in environmental conditions, and recovery from such a collapse can be difficult. We have used laboratory microbial ecosystems to directly measure theoretically proposed early warning signals of impending population collapse. Yeast cooperatively break down the sugar sucrose, meaning that below a critical size the population cannot sustain itself. We have demonstrated experimentally that changes in the fluctuations of the population size can serve as an early warning signal that the population is close to collapse. The cooperative nature of yeast growth on sucrose suggests that the population may be susceptible to ``cheater'' cells, which do not contribute to the public good and instead merely take advantage of the cooperative cells. We confirm this possibility experimentally and find that such social parasitism decreases the resilience of the population.

  1. Population extinction and the genetics of adaptation.

    Science.gov (United States)

    Orr, H Allen; Unckless, Robert L

    2008-08-01

    Theories of adaptation typically ignore the effect of environmental change on population size. But some environmental challenges--challenges to which populations must adapt--may depress absolute fitness below 1, causing populations to decline. Under this scenario, adaptation is a race; beneficial alleles that adapt a population to the new environment must sweep to high frequency before the population becomes extinct. We derive simple, though approximate, solutions to the probability of successful adaptation (population survival) when adaptation involves new mutations, the standing genetic variation, or a mixture of the two. Our results show that adaptation to such environmental challenges can be difficult when relying on new mutations at one or a few loci, and populations will often decline to extinction. PMID:18662122

  2. Keynes on population and economic growth.

    Science.gov (United States)

    Toye, J

    1997-01-01

    This article discusses the evolution of Keynes's thinking on population based on an unpublished paper from 1914, "Is the Problem of Population a Pressing and Important One Now?" The paper is reported to have 39 pages, but in fact there are many missing page numbers. Keynes's "Essays in Biography" (1933) follows the basic structure and much of the verbal detail of the first 16 pages of "Population." Chapter 2 of the "Economic Consequences of the Peace" discusses the key ideas of "Population." The passages in "Population" and Chapter 2 were probably the sources of a fierce controversy in 1923-24 between Keynes and W.H. Beveridge over Keynes' neo-Malthusianism. "Population" was the basis for the three themes that were central to Keynes's writing on population. Keynes's framework shifted from a global perspective in "Population" to a progressively narrower focus in the 1930s on England and Wales. Keynes was stronger in his advocacy of birth control in "Population" compared to later writings. Keynes was concerned about the quality of population but disagreed on the methods of achieving this. Keynes argued that 75% of the world was not subject to Malthusian dynamics, and the other 25% had developed technology to relieve population pressure. "Population" sketches out the rudiments of the welfare implications of the great divide between North and South population growth rates. Keynes assumes that overpopulation in the South will be compensated for by the international market without consideration of income deficits. Keynes argues against pronatalism. The 1933 essay shows Keynes shift away from Malthus as population expert to Malthus as political economist. By 1937, Keynes had recanted and was very aware of the uncertainty of the economy. The author believes that it is unfortunate that this 1913-14 manuscript remains unknown and, if known, misunderstood.

  3. The Magellanic Cloud PN population

    Science.gov (United States)

    Reid, Warren Alfred

    2015-08-01

    The Magellanic Clouds (MCs) become an area of focus when comparing how objects behave within low metallicity environments. Over the past few decades this has proven especially true of planetary nebulae (PNe) studies. The Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) allow us to study late stellar evolution in environments that are respectively about a half and a quarter the metallicity of the Milky Way. With a known distance and low reddening, the MCs allow the analysis of PNe across a whole galaxy and have value for multiple studies.Over the past twelve months we have used the UKST H-alpha survey to complete our search for faint PNe in the outer most LMC beyond the 64 deg2 area previously covered. Follow-up spectroscopy using AAOmega on the AAT and the 2.3m telescope at Siding Spring Observatory have yielded a further 132 new LMC PNe while confirming the 102 previously known in the outer LMC. Using the same method, we have confirmed 6 new PNe in the SMC and rejected several objects previously catalogued as PNe.Medium- and high-resolution spectra have been used to measure fluxes and derive central star temperatures for a series of research projects. Recent findings involving chemical abundances, central star properties and kinematics will be presented. The current [OIII]-based PNLF, apart from providing an excellent standard candle, contains information about the parent population. The new PNLF, which extends down 9 magnitudes, permits investigation of the faint end and provides clues to explain the insensitivity of the PNLF cutoff.To better understand the global properties of PNe I will present and compare H-alpha, NIR & MIR PNLFs, discuss PN dust properties and the changes that occur as PNe age. The positions of LMC PNe will then be shown as a function of their radial velocities and compared to the HI disk and other populations. I will also discuss recent radio confirmations of LMC and SMC PNe. Finally I will also take a look at recent multi

  4. Migration, population growth, and development.

    Science.gov (United States)

    1983-01-01

    In the 30 years between 1950 and 1980, the population of the developing world almost doubled--from 1.7 to 3.3 billion. Among the most conspicuous signs of this increase are the growth of cities and, in some areas, international labor migration. Since 1950 the cities in Africa, Asia, and Latin America have been growing more than twice as fast as those in North America and Europe. Some of the biggest cities are growing fastest--by as much as 8 percent each year. At this rate they will double in less than a decade. About 40 percent of this growth is due to migration and 60 percent to the children born in the cities to natives and the newly arrived migrants. Altogether, about one billion people (1,000 million) now live in developing-country cities, where fewer than 300 million lived in 1950. About 15 to 20 million workers, mostly from developing countries, are now international migrants. About half travel to Europe and the US, the rest to other developing countries. Many of the migrants, especially to the US, Europe, or the Middle East, want to bring their families eventually and settle permanently. Migration to African destinations is more likely to be temporary or seasonal, while Latin American and Asian patterns are mixed. Policy makers in developing countries are voicing concern about the highly visible social, economic, and political problems created by rapid urbanization and by large-scale international labor migration. While governments have tried a variety of policies to influence population distribution, most have been limited in scope and had little success. As long as birth rates remain high in some areas and large differences in wages exist between jobs in different places, most of these policies have little hope of stopping or reversing long-term trends. Family planning programs, although they do not create immediate jobs or higher wages in rural areas, can help to reduce the high birth rates that produce an ever-increasing supply of potential migrants

  5. [Sex education and population policies].

    Science.gov (United States)

    Rodriguez, G

    1991-01-01

    Controversy about sex education programs has hampered sustained actin or curricular extension in Mexico beyond programs directly related to demographic policies. The 1st sex education in Mexico perhaps dated back to 1908 when physicians and other health professionals, inspired by the eugenics movement, offered sex education to prevent venereal diseases and maternal and/infant mortality. A 2nd attempt occurred in 1916 in the context of the women's suffrage movement. The 2 perspectives were integrated in a sex education project in 1933, as part of the program of "revolutionary education" legitimized by the progressive and modernizing government of the time. Conservative groups including some parents' associations and religious organizations insisted on their exclusive right to provide sex education, and in following decades they opposed social programs related to primary health care and women's rights. In the 1960, the introduction to Mexico of modern contraceptives and the questioning by young people of virginity and the double standard of sexual morality were not aided by any formal program of sex education in Mexico. In the early 1970s, the need to transform fertility patterns led to establishment of formal sex education programs at the national level. The focus was on reproduction and demographic aspects. Most students were exposed to classes and textbooks covering puberty, human reproduction, contraception, and sexually transmitted diseases. The intense activity of the early years did not continue in the subsequent program, but currently, the threat of AIDS and economic and social pressures are prompting a new political will in favor of sex education. Sex education is seen as the main strategy for AIDS prevention programs. Homosexual groups are demonstrating a new political pressure as civil organizations integrated into a new sector demanding sex education. At the same time, population policies are assuming a predominant position in official discourse as a

  6. Population problem, a planner's view.

    Science.gov (United States)

    Chavan, S B

    1983-01-26

    A matter that is seriously being debated in India is whether the policy of "the stick or the carrot" should be adopted for controlling population growth, i.e., whether the country should depend upon "incentives" or "disincentives" for bringing about wider acceptance of family planning. In this planner's view, this debate is a nonissue in India's social and political context. Due to the fact that a major part of the country's resources are preempted for investment in economically productive sectors, it is not possible to follow a too liberal policy of offering "carrots" or high cash incentives. The family planning program does not function in a vacuum and must be integrated with the national perspective plan and economic priorities. This does not mean that there is no scheme for enabling the poorer sections of the population to avail themselves of the benefit of family planning. Free clinical facilities and supply of contraceptives and easier access to clinical services is certainly not part of the "carrot." If free medical and child care are taken into account, the benefits are quite substantial. Financial incentives are also given to acceptors of sterilization and IUD to compensate them for loss of wages sustained during hospitalization and convalescence. Yet, any incentives that are offered can only be very selected and limited in scope due to the vast numbers of target couples. Regarding the policy of the "stick" or disincentives, there is little room for this form of policy in India's democratic system. Disincentives in the form of denial of food, clothing, shelter, and medical facilities are out of the question for nonacceptors of family planning since these form part of the basic human rights. Some selective disincentives for discouraging "improvement parenthood" could be used when such disincentives can be built into contractual benefits like service conditions of employees of government and the organized sector. What is needed in India is a balanced policy

  7. Floating Population Increase and Its Influence on the Urban Population Situation: A Case Study in Beijing

    Institute of Scientific and Technical Information of China (English)

    Wu Peilin; Lu Qi

    2005-01-01

    Floating population is a special population group in China resulting from the implementation of household registration system. This paper uses a set of floating population survey data, population censuses data and statistical data to analyze the increase and influence of floating population on the urban population situations in Beijing. It is found that Beijing has experienced a rapid increase of floating population since the 1990s and that the increase of this group has become the key factor of the current population expansion in the city. Its distribution in the urban regions intensified and extended the subutbanization process of the capital. In addition,the population structures of sex, age, education and employment in Beijing have changed to some extent due to the influx of floating population.

  8. Dermatophytosis in special patient populations

    Institute of Scientific and Technical Information of China (English)

    Salama A Ouf; Tarek A Moussa; Alshimaa M Abd-Elmegeed; Samar R Eltahlawy

    2016-01-01

    Objective:To study the occurrence and prevalence of dermatomycosis in special patient populations suffering from diabetes, cancer and heart diseases. Methods: A total of 640 patients suffering from diabetes, 280 patients suffering from cancer and 210 patients suffering from heart diseases from Cairo City were evaluated for dermatophytosis at the dermatology clinics of four different hospitals from January 2005 to December 2006. Results: The presence of diabetes looks a risk factor for tinea pedis and tinea corporis. Tinea cruris and tinea unguium were not common among diabetics, while tinea capitis and tinea versicolor were completely missed. Tinea capitis followed by tinea pedis are the most common among cancer patients. Thirty cases were recorded for tinea among 210 patients with heart diseases of which tinea capitis and tinea versicolor were recorded once while the other clinical types of tinea were estimated in 6-8 patients for each type. Conclusions: The present investigation shows that diabetes remains to be a risk factor for dermatophytosis and cancer comes next due to the use of radioactive irradiation.

  9. Population Dynamics of Viral Inactivation

    Science.gov (United States)

    Freeman, Krista; Li, Dong; Behrens, Manja; Streletzky, Kiril; Olsson, Ulf; Evilevitch, Alex

    We have investigated the population dynamics of viral inactivation in vitrousing time-resolved cryo electron microscopy combined with light and X-ray scattering techniques. Using bacteriophage λ as a model system for pressurized double-stranded DNA viruses, we found that virions incubated with their cell receptor eject their genome in a stochastic triggering process. The triggering of DNA ejection occurs in a non synchronized manner after the receptor addition, resulting in an exponential decay of the number of genome-filled viruses with time. We have explored the characteristic time constant of this triggering process at different temperatures, salt conditions, and packaged genome lengths. Furthermore, using the temperature dependence we determined an activation energy for DNA ejections. The dependences of the time constant and activation energy on internal DNA pressure, affected by salt conditions and encapsidated genome length, suggest that the triggering process is directly dependent on the conformational state of the encapsidated DNA. The results of this work provide insight into how the in vivo kinetics of the spread of viral infection are influenced by intra- and extra cellular environmental conditions. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1252522.

  10. The sigma Orionis substellar population

    CERN Document Server

    Barrado y Navascués, D; Mundt, R; Martín, E L; Rebolo, R; Zapatero-Osorio, M R; Bailer-Jones, C A L; Navascu\\'es, David Barrado y; Mundt, Reinhard; Mart\\'{\\i}n, Eduardo L.; Rebolo, Rafael; Osorio, Mar\\'{\\i}a Rosa Zapatero; Bailer-Jones, Coryn A.L.

    2003-01-01

    VLT/FORS spectroscopy and 2MASS near-infrared photometry, together with previously known data, have been used to establish the membership and the properties of a sample of low-mass candidate members of the sigma Orionis cluster with masses spanning from 1 Msun down to about 0.013 Msun (i.e., deuterium-burning mass limit). We have observed K-band infrared excess and remarkably intense H(alpha) emission in various cluster members, which, in addition to the previously detected forbidden emision lines and the presence of LiI in absorption at 6708 A, have allowed us to tentatively classify sigma Orionis members as classical or weak-line TTauri stars and substellar analogs. Variability of the H(alpha) line has been investigated and detected in some objects. Based on the K-band infrared excesses and the intensity of H(alpha) emission, we estimate that the minimum disk frequency of the sigma Orionis low-mass population is in the range 5-12%.

  11. Oxytocin treatment in pediatric populations

    Directory of Open Access Journals (Sweden)

    Adrienne Elise Taylor

    2014-10-01

    Full Text Available The role of endogenous oxytocin as neuromodulator of birth, lactation and social behaviors is well-recognized. Moreover, the use of oxytocin as a facilitator of social and other behaviors is becoming more and more accepted. Many positive effects have been attributed to intranasal oxytocin administration in animals and humans; with current research highlighting encouraging advances in its potential for use in mental health disorders. The new frontier will be investigating the effective use of oxytocin in pediatric populations. Limited animal data is available on this. Large-scale human studies focusing on autism are currently under way, but many other possibilities seem to lie in the future. However, we need to know more about the risks and effects of repeated use on the developing brain and body. This paper will provide an overview of the current understanding of the role of endogenous oxytocin and its related neuropeptide systems in influencing behaviors, in particular attachment, and will review a the literature on the use of intranasal oxytocin in young animals, children (age range birth-12 years and adolescents (age range 13-19 years, b the expected benefits and risks based on the current research, and c the risks of oxytocin in children with severe psychopathology and early life trauma. The paper will conclude with a clinical perspective on these findings

  12. Supernova rates and stellar populations

    CERN Document Server

    Mannucci, F

    2007-01-01

    We discuss the results about the nature of type Ia Supernovae that can be derived by studying their rates in different stellar populations. While the evolution of SN photometry and spectra can constrain the explosion mechanism, the SN rate depends on the progenitor system. We review the current available data on rates as a function of parent galaxy color, morphology, star formation rate, radio luminosity and environment. By studying the variation of the rates with the color of the parent galaxy, a strong evidence was established that type Ia SNe come from both young and old stars. The dependence of the rates with the radio power of the parent galaxy is best reproduced by a bimodal distribution of delay time between the formation of the progenitor and its explosion as a SN. Cluster early-type galaxies show higher type Ia SN rate with respect to field galaxies, and this effect can be due either to traces of young stars or to differences in the delay time distribution.

  13. Small crater populations on Vesta

    CERN Document Server

    Marchi, S; O'Brien, D P; Schenk, P; Mottola, S; De Sanctis, M C; Kring, D A; Williams, D A; Raymond, C A; Russell, C T

    2013-01-01

    The NASA Dawn mission has extensively examined the surface of asteroid Vesta, the second most massive body in the main belt. The high quality of the gathered data provides us with an unique opportunity to determine the surface and internal properties of one of the most important and intriguing main belt asteroids (MBAs). In this paper, we focus on the size frequency distributions (SFDs) of sub-kilometer impact craters observed at high spatial resolution on several selected young terrains on Vesta. These small crater populations offer an excellent opportunity to determine the nature of their asteroidal precursors (namely MBAs) at sizes that are not directly observable from ground-based telescopes (i.e., below ~100 m diameter). Moreover, unlike many other MBA surfaces observed by spacecraft thus far, the young terrains examined had crater spatial densities that were far from empirical saturation. Overall, we find that the cumulative power-law index (slope) of small crater SFDs on Vesta is fairly consistent with...

  14. Population coding of somatic sensations

    Institute of Scientific and Technical Information of China (English)

    Qiufu Ma

    2012-01-01

    The somatic sensory system includes a variety of sensory modalities,such as touch,pain,itch,and temperature sensitivity.The coding of these modalities appears to be best explained by the population-coding theory,which is composed of the following features.First,an individual somatic sensory afferent is connected with a specific neural circuit or network (for simplicity,a sensory-labeled line),whose isolated activation is sufficient to generate one specific sensation under normal conditions.Second,labeled lines are interconnected through local excitatory and inhibitory interneurons.As a result,activation of one labeled line could modulate,or provide gate control of,another labeled line.Third,most sensory fibers are polymodal,such that a given stimulus placed onto the skin often activates two or multiple sensory-labeled lines;crosstalk among them is needed to generate one dominant sensation.Fourth and under pathological conditions,a disruption of the antagonistic interaction among labeled lines could open normally masked neuronal pathways,and allow a given sensory stimulus to evoke a new sensation,such as pain evoked by innocuous mechanical or thermal stimuli and itch evoked by painful stimuli.As a result of this,some sensory fibers operate along distinct labeled lines under normal versus pathological conditions.Thus,a better understanding of the neural network underlying labeled line crosstalk may provide new strategies to treat chronic pain and itch.

  15. Dynamics of Similar Populations: The Link Between Population Dynamics and Evolution

    OpenAIRE

    Meszena, G.; Gyllenberg, M.; F.J.A. Jacobs; J.A.J. Metz

    2005-01-01

    We provide the link between population dynamics and the dynamics of Darwinian evolution via studying the joint population dynamics of "similar" populations. Similarity implies that the "relative" dynamics of the populations is slow compared to, and decoupled from, their "aggregated" dynamics. The relative dynamics is simple, and captured by a Taylor expansion in the difference between the populations. The emerging evolution is directional, except at the "singular" points of the evolutionary s...

  16. The population structure of the Cryptosporidium parvum population in Scotland: A complex picture

    OpenAIRE

    Morrison, Liam J.; Mallon, Marianne E.; Smith, Huw V; MacLeod, Annette; Xiao, Lihua; Tait, Andy

    2008-01-01

    We genotyped 297 Scottish C. parvum samples using micro- and minisatellites. Treated as a single population, the population structure was epidemic. When regional populations were analysed, there was evidence of sub-population structure variations. This was dependent upon excluding sub-groups exhibiting significant genetic distance from the main population, implying genetic sub-structuring. We tested the hypothesis that these sub-groups originated outside the UK and demonstrated that one sub-g...

  17. Achieving true sustainability of zoo populations.

    Science.gov (United States)

    Lacy, Robert C

    2013-01-01

    For the last 30 years, cooperative management of irreplaceable animal populations in zoos and aquariums has focused primarily on the goal of minimizing genetic decay within defined time frames, and large advances have been made in technologies to optimize genetic management of closed populations. However, recent analyses have shown that most zoo programs are not projected to meet their stated goals. This has been described as a lack of achieving "sustainability" of the populations, yet by definition a goal of managed decay is not a plan for sustainability. True sustainability requires management of the resource in manner that does not deplete its value for the future. Achieving such sustainability for many managed populations may require changing from managing isolated populations to managing populations that are part of a broader metapopulation, with carefully considered exchange between populations across a spectrum of ex situ to in situ. Managing zoo populations as components of comprehensive conservation strategies for the species will require research on determinants of various kinds of genetic, physiological, behavioral, and morphological variation and their roles in population viability, development of an array of management techniques and tools, training of population managers in metapopulation management and integrated conservation planning, and projections of impacts of management strategies on the viability of the captive populations and all populations that are interactively managed or affected. Such a shift in goals and methods would result in zoo population management being an ongoing part of species conservation rather than short-term or isolated from species conservation. Zoo Biol. 32:19-26, 2013. © 2012 Wiley Periodicals, Inc.

  18. Recovery trends in marine mammal populations.

    Directory of Open Access Journals (Sweden)

    Anna M Magera

    Full Text Available Marine mammals have greatly benefitted from a shift from resource exploitation towards conservation. Often lauded as symbols of conservation success, some marine mammal populations have shown remarkable recoveries after severe depletions. Others have remained at low abundance levels, continued to decline, or become extinct or extirpated. Here we provide a quantitative assessment of (1 publicly available population-level abundance data for marine mammals worldwide, (2 abundance trends and recovery status, and (3 historic population decline and recent recovery. We compiled 182 population abundance time series for 47 species and identified major data gaps. In order to compare across the largest possible set of time series with varying data quality, quantity and frequency, we considered an increase in population abundance as evidence of recovery. Using robust log-linear regression over three generations, we were able to classify abundance trends for 92 spatially non-overlapping populations as Significantly Increasing (42%, Significantly Decreasing (10%, Non-Significant Change (28% and Unknown (20%. Our results were comparable to IUCN classifications for equivalent species. Among different groupings, pinnipeds and other marine mammals (sirenians, polar bears and otters showed the highest proportion of recovering populations, likely benefiting from relatively fast life histories and nearshore habitats that provided visibility and protective management measures. Recovery was less frequent among cetaceans, but more common in coastal than offshore populations. For marine mammals with available historical abundance estimates (n = 47, larger historical population declines were associated with low or variable recent recoveries so far. Overall, our results show that many formerly depleted marine mammal populations are recovering. However, data-deficient populations and those with decreasing and non-significant trends require attention. In particular

  19. Population structure and genetic diversity of native and invasive populations of Solanum rostratum (Solanaceae.

    Directory of Open Access Journals (Sweden)

    Jiali Zhao

    Full Text Available AIMS: We investigate native and introduced populations of Solanum rostratum, an annual, self-compatible plant that has been introduced around the globe. This study is the first to compare the genetic diversity of Solanum rostratum between native and introduced populations. We aim to (1 determine the level of genetic diversity across the studied regions; (2 explore the likely origins of invasive populations in China; and (3 investigate whether there is the evidence of multiple introductions into China. METHODS: We genotyped 329 individuals at 10 microsatellite loci to determine the levels of genetic diversity and to investigate population structure of native and introduced populations of S. rostratum. We studied five populations in each of three regions across two continents: Mexico, the U.S.A. and China. IMPORTANT FINDINGS: We found the highest genetic diversity among Mexican populations of S. rostratum. Genetic diversity was significantly lower in Chinese and U.S.A. populations, but we found no regional difference in inbreeding coefficients (F IS or population differentiation (F ST. Population structure analyses indicate that Chinese and U.S.A. populations are more closely related to each other than to sampled Mexican populations, revealing that introduced populations in China share an origin with the sampled U.S.A. populations. The distinctiveness between some introduced populations indicates multiple introductions of S. rostratum into China.

  20. [Food and population: study of three countries].

    Science.gov (United States)

    1988-12-01

    In 1985, despite a nearly 25% worldwide surplus of cereals, more than 700 million poor people had insufficient food and some 17 million children died of malnutrition or related causes. 16% of the developing world's population is undernourished. Rapid population growth is a major reason for the world's hunger. Large families exhaust the resources of many urban couples and rural couples with little land. Closely spaced pregnancies deplete the nutritional resources of the mother and lead to low birth weight babies and inadequate lactation. Population growth in already densely populated countries reduces the land available for each family, inevitably contributing to poverty and rural malnutrition. Unemployment and underemployment reach alarming proportions in the city, where the combination of high fertility rates and migration from the countryside have produced growth twice that of the world population as a whole. Few developing countries have been able to generate sufficient investment to create new jobs for all seeking them. Unstable governments attempt to pacify urban unrest by subsidizing food prices and concentrating social and economic investments in the cities, causing further deterioration in rural conditions. Today more than 60 countries have food deficits, although not all are suffering. India, Kenya, and Mexico are 3 countries that have had some success in balancing population growth and food production, but each still has undernourished population sectors because of economic policies that fail to provide sufficient help to their poor and because of implacable population growth. Ending malnutrition in the 3 countries will require reducing the cost of food for households and increasing their incomes, but both objectives are made more difficult by rapid population growth. As a result of the green revolution and other factors, food production in India has tripled since 1950, but population has almost doubled in the same years. With rapid population growth, per

  1. Coexistence of competing stage-structured populations.

    KAUST Repository

    Fujiwara, Masami

    2011-10-05

    This paper analyzes the stability of a coexistence equilibrium point of a model for competition between two stage-structured populations. In this model, for each population, competition for resources may affect any one of the following population parameters: reproduction, juvenile survival, maturation rate, or adult survival. The results show that the competitive strength of a population is affected by (1) the ratio of the population parameter influenced by competition under no resource limitation (maximum compensatory capacity) over the same parameter under a resource limitation due to competition (equilibrium rate) and (2) the ratio of interspecific competition over intraspecific competition; this ratio was previously shown to depend on resource-use overlap. The former ratio, which we define as fitness, can be equalized by adjusting organisms\\' life history strategies, thereby promoting coexistence. We conclude that in addition to niche differentiation among populations, the life history strategies of organisms play an important role in coexistence.

  2. Malthusian Population Dynamics: Theory and Evidence

    OpenAIRE

    Ashraf, Quamrul; Galor, Oded

    2008-01-01

    This paper empirically tests the existence of Malthusian population dynamics in the pre-Industrial Revolution era. The theory suggests that, during the agricultural stage of development, resource surpluses beyond the maintenance of subsistence consumption were channeled primarily into population growth. In particular, societies naturally blessed by higher land productivity would have supported larger populations, given the level of socioeconomic development. Moreover, given land productivity,...

  3. Population effects of increased climate variation

    OpenAIRE

    Drake, John M.

    2005-01-01

    Global circulation models predict and numerous observations confirm that anthropogenic climate change has altered high-frequency climate variability. However, it is not yet well understood how changing patterns of environmental variation will affect wildlife population dynamics and other ecological processes. Theory predicts that a population's long-run growth rate is diminished and the chance of population extinction is increased as environmental variation increases. This results from the fa...

  4. Average Drift Analysis and Population Scalability

    OpenAIRE

    He, Jun; Yao, Xin

    2013-01-01

    This paper aims to study how the population size affects the computation time of evolutionary algorithms in a rigorous way. The computation time of an evolutionary algorithm can be measured by either the expected number of generations (hitting time) or the expected number of fitness evaluations (running time) to find an optimal solution. Population scalability is the ratio of the expected hitting time between a benchmark algorithm and an algorithm using a larger population size. Average drift...

  5. Intraspecific competition delays recovery of population structure.

    Science.gov (United States)

    Liess, Matthias; Foit, Kaarina

    2010-04-01

    Ecotoxicological field studies have shown that total abundance and biomass often recover shortly after pulsed toxicant stress. In contrast, population structure showed comparatively long-term alterations before reaching pre-treatment conditions. We investigated two mechanisms that may explain the prolonged recovery of population structure: latent toxicant effects on life-history traits on the individual level and competition on the population level. To test these hypotheses we exposed populations of Daphnia magna to a pulse of the pyrethroid Fenvalerate. For several generations the populations were kept at two different degrees of competition: strong competition at carrying capacity and reduced competition maintained by simulated predation. After disturbance due to Fenvalerate exposure, biomass recovered after 14-17 days. In contrast, size structure characterised by a lack of large and dominance of small organisms recovered after 43 days in populations with strong competition. Size structure recovered twice faster in populations with reduced competition. We explain this as follows: due to toxicant induced mortality, food availability and consequently birth rate increased and populations were dominated by small individuals. In populations without predation, these cohorts grew and eventually exerted high intraspecific competition that (i) stopped further growth of juveniles and (ii) increased mortality of adults. These demographic processes were mainly responsible for the prolonged recovery of size structure. In contrast, for populations with predation, the regular harvest of individuals reduced competition. Juveniles developed continuously, allowing a fast recovery of size structure in these dynamic populations. In risk assessment the duration for populations to recover from (toxicant) stress, is crucial for the determination of ecological acceptable effects. We conclude that competition needs to be considered in order to understand and predict recovery of size

  6. Population Dynamics of Genetic Regulatory Networks

    Science.gov (United States)

    Braun, Erez

    2005-03-01

    Unlike common objects in physics, a biological cell processes information. The cell interprets its genome and transforms the genomic information content, through the action of genetic regulatory networks, into proteins which in turn dictate its metabolism, functionality and morphology. Understanding the dynamics of a population of biological cells presents a unique challenge. It requires to link the intracellular dynamics of gene regulation, through the mechanism of cell division, to the level of the population. We present experiments studying adaptive dynamics of populations of genetically homogeneous microorganisms (yeast), grown for long durations under steady conditions. We focus on population dynamics that do not involve random genetic mutations. Our experiments follow the long-term dynamics of the population distributions and allow to quantify the correlations among generations. We focus on three interconnected issues: adaptation of genetically homogeneous populations following environmental changes, selection processes on the population and population variability and expression distributions. We show that while the population exhibits specific short-term responses to environmental inputs, it eventually adapts to a robust steady-state, largely independent of external conditions. Cycles of medium-switch show that the adapted state is imprinted in the population and that this memory is maintained for many generations. To further study population adaptation, we utilize the process of gene recruitment whereby a gene naturally regulated by a specific promoter is placed under a different regulatory system. This naturally occurring process has been recognized as a major driving force in evolution. We have recruited an essential gene to a foreign regulatory network and followed the population long-term dynamics. Rewiring of the regulatory network allows us to expose their complex dynamics and phase space structure.

  7. Determination of Even Degree of Animal Population

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The even degree of animal population is generlay measured by the coefficient of variation of major eco- nomic characters. Facing the coefficient of variation,a statistic with complex properties,we achieved indirectly the determination of confidence interval for even degree of an animal population by analysing the reciprocal of the statistic. The sample size which is suitable to the determination of the even degree of an animal population was probed into within the extent of permissive estimation error.

  8. Determination of Even Degree of Animal Population

    Institute of Scientific and Technical Information of China (English)

    SongRen-xue; YangYun-qing

    1999-01-01

    The even degree of animal population is generlay measured by the coefficient of variation of major economic characters.Facing the coefficient of variation,a statistic with complex properties,we achieved indirectly the determination of confidence interval for even degree of an animal population by analysing the reciprocal of the statistic.The sample size which is suitable to the determination of the even degree of an animal population was probed into within the extent of permissive estimation error.

  9. Modelling urban - rural population growth in China

    OpenAIRE

    Shen, J; N A Spence

    1996-01-01

    The population of China is still growing despite a dramatic decline in fertility in the past two decades. There are marked urban - rural differentials in fertility and, as a result, the pace of urbanization has significant effects on population growth. In this research an attempt is made to model urban - rural population growth in China. A demoeconomic model of urban and rural sectors is calibrated to account for the long-term trend of urbanization in China. Two important components of urban ...

  10. Population and demographic development in community Bogomila

    OpenAIRE

    Mijalov, Risto; Temjanovski, Riste

    2000-01-01

    The intensive processes of the industrialization, depopulation and migration movement had reflection on the demographic structure of the population. The Rural settlements had decreasing level with populations where population changes have occurred in all structure: age structure, the economic structure, the education etc. This process is actual in new community Bogomila. Here is given a synthetic survey on intensive occurs in this Community. It is necessary adequate demographic policy to stop...

  11. Surface Brightness Fluctuations as Stellar Population Indicators

    OpenAIRE

    Blakeslee, John P

    2009-01-01

    Surface Brightness Fluctuations (SBF) can provide useful information about the unresolved stellar content of early-type galaxies and spiral bulges. The absolute SBF magnitude Mbar in a given passband depends on the properties of the stellar population and can be predicted by population synthesis models. SBF measurements in different bandpasses are sensitive to different evolutionary stages within the galaxy stellar population. Near-IR SBF magnitudes are sensitive to the evolution of stars wit...

  12. [The population problem in global modeling].

    Science.gov (United States)

    Naidenova, P

    1986-01-01

    Developments during the past 15 years in population modeling are critically reviewed. The author notes that while population variables were treated as endogenous in earlier models developed by the Club of Rome, later models have treated such variables as exogenous. The need to link demographic factors to structural changes and economic growth, in accordance with Marxist-Leninist population theory, is noted. (SUMMARY IN ENG AND RUS) PMID:12280533

  13. Diversity Generation in Evolving Microbial Populations

    DEFF Research Database (Denmark)

    Markussen, Trine

    diversity has been documented in contemporary respiratory specimens, it is less clear to what extent within-patient diversity contributes to the overall population structure and whether the population is geographically or homogeneously distributed throughout the airways. The focus of this thesis has been...... and maintenance of population diversity of infecting pathogens. Furthermore, fine-tuning of global regulatory networks by modification of transcriptional regulators has fundamental roles in successful adaptation of P. aeruginosa to the CF environment....

  14. Darwin and Lotka: Two Concepts of Population

    Directory of Open Access Journals (Sweden)

    Philip Kreager

    2009-10-01

    Full Text Available Population was the subject of two major conceptual developments in the second quarter of the 20th century. Both were inspired by evolutionary biology. Lotka developed a mathematics of evolution in human and other species by analogy to thermodynamic models. His theory followed demographic practice in treating populations as closed units, commonly macro-scale, and in inferring underlying processes of change from aggregate outcomes. In contrast, the evolutionary synthesis - a collaborative product of research in experimental and population genetics, natural history, and related fields of biology - followed Darwin in insisting that close observation of small-scale population processes and local environments is necessary to understand population change. Because gene-environment interactions rely on expanding and contracting networks of individuals, the populations in question are by nature open. Despite the apparent conflict between these positions, the synthesis broke new ground in the history of population thought by showing how the two approaches could be combined. Demography, however, moved away from evolutionary and population biology as a source of theory in the early post-war era, and this conceptual redevelopment of population was scarcely remarked upon. More recently, the tremendous development of genetics has recalled demographers' attention to evolutionary theory as an inescapable element of modern population thought. This paper provides a historical introduction to mid-20th-century developments in Darwinian population thinking, and the implications of its dual conceptualisation of population for demography. Its potential importance extends beyond the problem of gene-environment interactions to many aspects of social network analysis.

  15. Sewage Reflects the Microbiomes of Human Populations

    OpenAIRE

    Ryan J Newton; McLellan, Sandra L.; Dila, Deborah K.; Vineis, Joseph H; Morrison, Hilary G; Eren, A. Murat; Sogin, Mitchell L.

    2015-01-01

    ABSTRACT Molecular characterizations of the gut microbiome from individual human stool samples have identified community patterns that correlate with age, disease, diet, and other human characteristics, but resources for marker gene studies that consider microbiome trends among human populations scale with the number of individuals sampled from each population. As an alternative strategy for sampling populations, we examined whether sewage accurately reflects the microbial community of a mixt...

  16. Fisheries. Population of origin of Atlantic cod.

    Science.gov (United States)

    Nielsen, E E; Hansen, M M; Schmidt, C; Meldrup, D; Grønkjaer, P

    2001-09-20

    Most of the world's cod (Gadus morhua) fisheries are now tightly regulated or closed altogether. Being able to link individual fish to their population of origin would assist enormously in policing regulations and in identifying poachers. Here we show that microsatellite genetic markers can be used to assign individual cod from three different populations in the northeastern Atlantic Ocean to their population of origin. PMID:11565021

  17. Native Colombia: Contact, Conquest and Colonial Populations

    OpenAIRE

    Villamarín, Juan; Villamarín, Judith

    2003-01-01

    Studies done on Colombia’s population history during the last three decades have been influenced by the ideas, methods and approaches of Woodrow Borah. We will discuss three issues that he and Sherburne Cook considered in the course of their work on Latin American demography – probable size of native populations on the eve of European contact; the effects of climate and elevation on the intensity of different groups’ decline; and the impact on native populations of diseases brought from the O...

  18. IIASA's Population Project: Aging and Changing Lifestyles

    OpenAIRE

    Rogers, A

    1982-01-01

    Low fertility levels in IIASA countries are creating aging populations whose demands for health care and income maintenance (social security) will increase to unprecedented levels, thereby calling forth policies that will seek to promote increased family care and worklife flexibility. The Population Project will examine current patterns of population aging and changing lifestyles in IIASA countries, project the needs for health and income support that such patterns are likely to generate duri...

  19. Population growth and forest sustainability in Africa

    OpenAIRE

    Simplice A, Asongu; Brian A., Jingwa

    2011-01-01

    Recent distressing trends in climate change, population explosion and deforestation inspired this paper, which completes existing literature by providing empirical justification to hypothetical initiatives on the impact of population growth on forest sustainability in Africa. Using three instruments of forest exploitation, the study shows how rural, agricultural and national population growths affect forest-area and agricultural-land. In this particular study the findings indicate that instru...

  20. Use of Population Genetics to Assess the Ecology, Evolution, and Population Structure of Coccidioides.

    Science.gov (United States)

    Teixeira, Marcus M; Barker, Bridget M

    2016-06-01

    During the past 20 years, a general picture of the genetic diversity and population structure of Coccidioides, the causal agent of coccidioidomycosis (Valley fever), has emerged. The genus consists of 2 genetically diverse species, C. immitis and C. posadasii, each of which contains 1 or more distinct populations with limited gene flow. Genotypic data indicate that C. immitis is divided into 2 subpopulations (central and southern California populations) and C. posadasii is divided into 3 subpopulations (Arizona, Mexico, and Texas/South America populations). However, admixture within and among these populations and the current paucity of environmental isolates limit our understanding of the population genetics of Coccidioides. We assessed population structure of Coccidioides in Arizona by analyzing 495 clinical and environmental isolates. Our findings confirm the population structure as previously described and indicate a finer scale population structure in Arizona. Environmental isolates appear to have higher genetic diversity than isolates from human patients. PMID:27191589

  1. Bayesian analysis of genetic differentiation between populations.

    Science.gov (United States)

    Corander, Jukka; Waldmann, Patrik; Sillanpää, Mikko J

    2003-01-01

    We introduce a Bayesian method for estimating hidden population substructure using multilocus molecular markers and geographical information provided by the sampling design. The joint posterior distribution of the substructure and allele frequencies of the respective populations is available in an analytical form when the number of populations is small, whereas an approximation based on a Markov chain Monte Carlo simulation approach can be obtained for a moderate or large number of populations. Using the joint posterior distribution, posteriors can also be derived for any evolutionary population parameters, such as the traditional fixation indices. A major advantage compared to most earlier methods is that the number of populations is treated here as an unknown parameter. What is traditionally considered as two genetically distinct populations, either recently founded or connected by considerable gene flow, is here considered as one panmictic population with a certain probability based on marker data and prior information. Analyses of previously published data on the Moroccan argan tree (Argania spinosa) and of simulated data sets suggest that our method is capable of estimating a population substructure, while not artificially enforcing a substructure when it does not exist. The software (BAPS) used for the computations is freely available from http://www.rni.helsinki.fi/~mjs. PMID:12586722

  2. [Issues on the strategy of population development].

    Science.gov (United States)

    Wu, Z

    1986-03-01

    The author, who works at the Population Institute of Sichuan Financial University, deals with issues regarding the strategy of population development in China and applies the population theories of Marxist and Leninist thought. The importnace of establishing a strategy of population development, in order to create an "optimum situation" for China's population in the future, specifically within the next 50-100 years is stressed. In addition to emphasizing the value of family planning and the use of birth control as a means of achieving this optimum population, it is reommeneded that the central government as well as the local governments of each province set up a strategic plan spanning 10, 20, 50, or 100 years with the aim of creating such optimum situation. The Marxist term optimum population is used to refer to a situation in which an area's population is o foptimum quality, quantity, and geographical distribution. The Marxist principle of 2 types of production are noted: production of material and production of population. General as well as local strategies are of extreme importance for the development of productive strength in China now and in the next 50-100 years. PMID:12341131

  3. Glitch Statistics of Radio Pulsars : Multiple populations

    CERN Document Server

    Konar, Sushan

    2014-01-01

    There appears to be more than one statistically different populations in the energy distribution of glitches, strongly indicative of different mechanisms accessing different energy ranges responsible for them.

  4. Population-dependent effects of ocean acidification.

    Science.gov (United States)

    Wood, Hannah L; Sundell, Kristina; Almroth, Bethanie Carney; Sköld, Helén Nilsson; Eriksson, Susanne P

    2016-04-13

    Elevated carbon dioxide levels and the resultant ocean acidification (OA) are changing the abiotic conditions of the oceans at a greater rate than ever before and placing pressure on marine species. Understanding the response of marine fauna to this change is critical for understanding the effects of OA. Population-level variation in OA tolerance is highly relevant and important in the determination of ecosystem resilience and persistence, but has received little focus to date. In this study, whether OA has the same biological consequences in high-salinity-acclimated population versus a low-salinity-acclimated population of the same species was investigated in the marine isopod Idotea balthica.The populations were found to have physiologically different responses to OA. While survival rate was similar between the two study populations at a future CO2 level of 1000 ppm, and both populations showed increased oxidative stress, the metabolic rate and osmoregulatory activity differed significantly between the two populations. The results of this study demonstrate that the physiological response to OA of populations from different salinities can vary. Population-level variation and the environment provenance of individuals used in OA experiments should be taken into account for the evaluation and prediction of climate change effects.

  5. Population development in Ljubljana urban region

    Directory of Open Access Journals (Sweden)

    Dejan Rebernik

    2004-12-01

    Full Text Available The paper presents the main characteristic of population development and urbanisation processes in Ljubljana and Ljubljana urban region. Up to the end of the seventies fast population growth was a consequence of strong immigration from rural parts of Slovenia and the rest of Yugoslavia. In the eighties and nineties deconcentration of population within the region with intense suburbanisation and depopulation of inner city and older residential neighbourhoods were the main urbanisation processes. In the second half of the nineties the highest population growth was recorded in dispersed rural settlements in the periphery of the region. In some parts of the inner city reurbanisation and gentrification occurred.

  6. Population-dependent effects of ocean acidification.

    Science.gov (United States)

    Wood, Hannah L; Sundell, Kristina; Almroth, Bethanie Carney; Sköld, Helén Nilsson; Eriksson, Susanne P

    2016-04-13

    Elevated carbon dioxide levels and the resultant ocean acidification (OA) are changing the abiotic conditions of the oceans at a greater rate than ever before and placing pressure on marine species. Understanding the response of marine fauna to this change is critical for understanding the effects of OA. Population-level variation in OA tolerance is highly relevant and important in the determination of ecosystem resilience and persistence, but has received little focus to date. In this study, whether OA has the same biological consequences in high-salinity-acclimated population versus a low-salinity-acclimated population of the same species was investigated in the marine isopod Idotea balthica.The populations were found to have physiologically different responses to OA. While survival rate was similar between the two study populations at a future CO2 level of 1000 ppm, and both populations showed increased oxidative stress, the metabolic rate and osmoregulatory activity differed significantly between the two populations. The results of this study demonstrate that the physiological response to OA of populations from different salinities can vary. Population-level variation and the environment provenance of individuals used in OA experiments should be taken into account for the evaluation and prediction of climate change effects. PMID:27053741

  7. Diabetes in Population Isolates: Lessons from Greenland.

    Science.gov (United States)

    Grarup, Niels; Moltke, Ida; Albrechtsen, Anders; Hansen, Torben

    2015-01-01

    Type 2 diabetes (T2D) is an increasing health problem worldwide with particularly high occurrence in specific subpopulations and ancestry groups. The high prevalence of T2D is caused both by changes in lifestyle and genetic predisposition. A large number of studies have sought to identify the genetic determinants of T2D in large, open populations such as Europeans and Asians. However, studies of T2D in population isolates are gaining attention as they provide several advantages over open populations in genetic disease studies, including increased linkage disequilibrium, homogeneous environmental exposure, and increased allele frequency. We recently performed a study in the small, historically isolated Greenlandic population, in which the prevalence of T2D has increased to more than 10%. In this study, we identified a common nonsense variant in TBC1D4, which has a population-wide impact on glucose-stimulated plasma glucose, serum insulin levels, and T2D. The variant defines a specific subtype of non-autoimmune diabetes characterized by decreased post-prandial glucose uptake and muscular insulin resistance. These and other recent findings in population isolates illustrate the value of performing medical genetic studies in genetically isolated populations. In this review, we describe some of the advantages of performing genetic studies of T2D and related cardio-metabolic traits in a population isolate like the Greenlandic, and we discuss potentials and perspectives for future research into T2D in this population. PMID:27111118

  8. Population genomics of natural and experimental populations of guppies (Poecilia reticulata).

    Science.gov (United States)

    Fraser, Bonnie A; Künstner, Axel; Reznick, David N; Dreyer, Christine; Weigel, Detlef

    2015-01-01

    Convergent evolution represents one of the best lines of evidence for adaptation, but few cases of phenotypic convergence are understood at the genetic level. Guppies inhabiting the Northern Mountain Range of Trinidad provide a classic example of phenotypic convergent evolution, where adaptation to low or high predation environments has been found for a variety of traits. A major advantage of this system is the possibility of long-term experimental studies in nature, including transplantation from high to low predation sites. We used genome scans of guppies from three natural high and low predation populations and from two experimentally established populations and their sources to examine whether phenotypic convergent evolution leaves footprints at the genome level. We used population-genetic modelling approaches to reconstruct the demographic history and migration among sampled populations. Naturally colonized low predation populations had signatures of increased effective population size since colonization, while introduction populations had signatures of decreased effective population size. Only a small number of regions across the genome had signatures of selection in all natural populations. However, the two experimental populations shared many genomic regions under apparent selection, more than expected by chance. This overlap coupled with a population decrease since introduction provides evidence for convergent selection occurring in the two introduced populations. The lack of genetic convergence in the natural populations suggests that convergent evolution is lacking in these populations or that the effects of selection become difficult to detect after a long-time period.

  9. Copy number variation of ribosomal DNA and Pokey transposons in natural populations of Daphnia

    Directory of Open Access Journals (Sweden)

    Eagle Shannon HC

    2012-03-01

    Full Text Available Abstract Background Despite their ubiquity and high diversity in eukaryotic genomes, DNA transposons are rarely encountered in ribosomal DNA (rDNA. In contrast, R-elements, a diverse group of non-LTR retrotransposons, specifically target rDNA. Pokey is a DNA transposon that targets a specific rDNA site, but also occurs in many other genomic locations, unlike R-elements. However, unlike most DNA transposons, Pokey has been a stable component of Daphnia genomes for over 100 million years. Here we use qPCR to estimate the number of 18S and 28S ribosomal RNA genes and Pokey elements in rDNA (rPokey, as well as other genomic locations (gPokey in two species of Daphnia. Our goals are to estimate the correlation between (1 the number of 18S and 28S rRNA genes, (2 the number of 28S genes and rPokey, and (3 the number of rPokey and gPokey. In addition, we ask whether Pokey number and distribution in both genomic compartments are affected by differences in life history between D. pulex and D. pulicaria. Results We found differences in 18S and 28S gene number within isolates that are too large to be explained by experimental variation. In general, Pokey number within isolates is modest (Pokey. There is no correlation between the number of rRNA genes and rPokey, or between rPokey and gPokey. However, we identified three isolates with unusually high numbers of both rPokey and gPokey, which we infer is a consequence of recent transposition. We also detected other rDNA insertions (rInserts that could be degraded Pokey elements, R- elements or the divergent PokeyB lineage recently detected in the Daphnia genome sequence. Unlike rPokey, rInserts are positively correlated with rRNA genes, suggesting that they are amplified by the same mechanisms that amplify rDNA units even though rPokey is not. Overall, Pokey frequency and distribution are similar in D. pulex and D. pulicaria suggesting that differences in life history have no impact on Pokey. Conclusions The

  10. The effects of harvest on waterfowl populations

    Science.gov (United States)

    Cooch, Evan G.; Guillemain, Matthieu; Boomer, G Scott; Lebreton, Jean-Dominique; Nichols, James D.

    2014-01-01

    Change in the size of populations over space and time is, arguably, the motivation for much of pure and applied ecological research. The fundamental model for the dynamics of any population is straightforward: the net change in the abundance is the simple difference between the number of individuals entering the population and the number leaving the population, either or both of which may change in response to factors intrinsic and extrinsic to the population. While harvest of individuals from a population constitutes a clear extrinsic source of removal of individuals, the response of populations to harvest is frequently complex, reflecting an interaction of harvest with one or more population processes. Here we consider the role of these interactions, and factors influencing them, on the effective harvest management of waterfowl populations. We review historical ideas concerning harvest and discuss the relationship(s) between waterfowl life histories and the development and application of population models to inform harvest management. The influence of population structure (age, spatial) on derivation of optimal harvest strategies (with and without explicit consideration of various sources of uncertainty) is considered. In addition to population structure, we discuss how the optimal harvest strategy may be influenced by: 1) patterns of density-dependence in one or more vital rates, and 2) heterogeneity in vital rates among individuals within an age-sex-size class. Although derivation of the optimal harvest strategy for simple population models (with or without structure) is generally straightforward, there are several potential difficulties in application. In particular, uncertainty concerning the population structure at the time of harvest, and the ability to regulate the structure of the harvest itself, are significant complications. We therefore review the evidence of effects of harvest on waterfowl populations. Some of this evidence has

  11. Population and Economic Growth in Developing Countries

    Directory of Open Access Journals (Sweden)

    Minh Quang Dao

    2012-01-01

    Full Text Available This paper examines the economic effects of the demographic transition in developing countries. Based on data from the World Bank and using a sample of forty-three developing economies, we find that the growth rate of per capita GDP is linearly dependent upon population growth, both the young and old dependency ratios, the mortality rate, and whether or not the rate of population growth is less than 1.2 percent per year. Using interaction variables in light of the severe degree of multicollinearity among explanatory variables, we find that per capita GDP growth linearly depends on population growth, the old dependency ratio, the mortality rate, and the interactions between population growth and both the young and old dependency ratios, between population growth and whether or not the rate of population growth is less than 1.2 percent per year, and the interaction term between the young dependency ratio and whether or not the rate of population growth is less than 1.2 percent per year. Statistical results of such an empirical examination will assist governments in devising policies aimed at influencing the economic effects of the demographic transition. Data for all variables are from the 2010 World Development Indicators. We apply the least-squares estimation technique in a multivariate linear regression. We also test for the nonlinear effect of population growth on economic growth and note that the introduction of interaction terms between population growth and dependency ratios as well as those between whether or not the population growth rate is less than 1.2 percent and population growth and the young dependency ratio yields better statistical results.

  12. The Population Problem as Economic Disarticulation.

    Science.gov (United States)

    Yapa, Lakshman S.

    1985-01-01

    Overpopulation exists when people lack the basic means of subsistence, or when there is massive and permanent unemployment. Population problems of developing countries are examined, and causes of high rates of fertility are discussed. The utilization of productive resources in solving population problems is also examined. (RM)

  13. Scaling of Attitudes Toward Population Problems

    Science.gov (United States)

    Watkins, George A.

    1975-01-01

    This study related population problem attitudes and socioeconomic variables. Six items concerned with number of children, birth control, family, science, economic depression, and overpopulation were selected for a Guttman scalogram. Education, occupation, and number of children were correlated with population problems scale scores; marital status,…

  14. Planning for an ageing population: strategic considerations

    LENUS (Irish Health Repository)

    O'Shea, Dr Eamon

    2005-01-01

    This report presents both the proceedings of the Council’s conference, Planning for an Ageing Population: Strategic Considerations, and the Council’s discussion paper, ‘The Older Population: Information Issues and Deficits’, which was introduced at that conference.\\r\

  15. Population structure of Atlantic Mackerel (Scomber scombrus)

    DEFF Research Database (Denmark)

    Jansen, Teunis; Gislason, Henrik

    2013-01-01

    model where the population structure of mackerel is described as a dynamic cline, rather than as connected contingents. Temporal changes in hydrography and mackerel behavior may affect the steepness of the cline at various locations. The new interpretation of the population structure of Atlantic...

  16. Developing IEC Strategies for Population Programmes.

    Science.gov (United States)

    Cohen, Sylvie I.

    1993-01-01

    Proposes a systematic and stepwise approach to the design of population information, education, and communication (IEC) strategies. Clarifies the role of IEC in population programs, details methodological steps to follow in IEC strategy development, and identifies types of research and sources of data needed. (MDH)

  17. A Bayesian Bootstrap for a Finite Population

    OpenAIRE

    Lo, Albert Y.

    1988-01-01

    A Bayesian bootstrap for a finite population is introduced; its small-sample distributional properties are discussed and compared with those of the frequentist bootstrap for a finite population. It is also shown that the two are first-order asymptotically equivalent.

  18. City Population Growth and Economic Growth

    DEFF Research Database (Denmark)

    Freire-Gibb, L. Carlos

    2008-01-01

    This article looks at the relationship between city population growth (intimately related to population proximity), and economic development. The hypothesis is that wherever dynamic and inclusive networks exist, there are more opportunities for economic development in this place. When these types...

  19. [Does Poland need a population policy?].

    Science.gov (United States)

    Holzer, J Z

    1986-01-01

    An attempt is made to present some important issues relative to population policy, and to prove the need for such a policy in Poland. A population policy is defined as a combination of direct and indirect actions by the state to influence the growth of the population, as well as its distribution and structure. As in most European countries, an average Polish household has 2 children, a smallpercentage of families have 3 children, and many households have no children, or only 1 child. Therefore, a probirth policy is recommended to maintain the birth rate at 2.10-2.20. However, within such a policy, a family should be free to make its own plans for reproduction. Contraceptives must be available and abortion should be permitted. Given the unsaturated market and permanent shortage of essential goods, a Polish population policy can only be considered from the perspective of a general socioeconomic policy. To pursue the goals of an efficient population policy, an acceptable standard of living should be achieved. Strategically, population policy in Poland should be aimed at creating an optimal structure that would correspond to the stable and, at some point, stationary population model. An evolutionary transition to a stable (or stationary) model should take place over 2 or 3 generations. Such structural changes should go hand-in-hand with permanent improvements in the health, welfare, and cultural life of the population. PMID:12314830

  20. Fishing amplifies forage fish population collapses

    Science.gov (United States)

    Essington, Timothy E.; Moriarty, Pamela E.; Froehlich, Halley E.; Hodgson, Emma E.; Koehn, Laura E.; Oken, Kiva L.; Siple, Margaret C.; Stawitz, Christine C.

    2015-01-01

    Forage fish support the largest fisheries in the world but also play key roles in marine food webs by transferring energy from plankton to upper trophic-level predators, such as large fish, seabirds, and marine mammals. Fishing can, thereby, have far reaching consequences on marine food webs unless safeguards are in place to avoid depleting forage fish to dangerously low levels, where dependent predators are most vulnerable. However, disentangling the contributions of fishing vs. natural processes on population dynamics has been difficult because of the sensitivity of these stocks to environmental conditions. Here, we overcome this difficulty by collating population time series for forage fish populations that account for nearly two-thirds of global catch of forage fish to identify the fingerprint of fisheries on their population dynamics. Forage fish population collapses shared a set of common and unique characteristics: high fishing pressure for several years before collapse, a sharp drop in natural population productivity, and a lagged response to reduce fishing pressure. Lagged response to natural productivity declines can sharply amplify the magnitude of naturally occurring population fluctuations. Finally, we show that the magnitude and frequency of collapses are greater than expected from natural productivity characteristics and therefore, likely attributed to fishing. The durations of collapses, however, were not different from those expected based on natural productivity shifts. A risk-based management scheme that reduces fishing when populations become scarce would protect forage fish and their predators from collapse with little effect on long-term average catches. PMID:25848018

  1. Representativeness in population-based studies

    DEFF Research Database (Denmark)

    Drivsholm, Thomas Bo; Eplov, Lene Falgaard; Davidsen, Michael;

    2006-01-01

    Decreasing rates of participation in population-based studies increasingly challenge the interpretation of study results, in both analytic and descriptive epidemiology. Consequently, estimates of possible differences between participants and non-participants are increasingly important for the...... interpretation of study results and generalization to the background population....

  2. Scale Reliability Evaluation with Heterogeneous Populations

    Science.gov (United States)

    Raykov, Tenko; Marcoulides, George A.

    2015-01-01

    A latent variable modeling approach for scale reliability evaluation in heterogeneous populations is discussed. The method can be used for point and interval estimation of reliability of multicomponent measuring instruments in populations representing mixtures of an unknown number of latent classes or subpopulations. The procedure is helpful also…

  3. Hispanic Population Growth and Rural Income Inequality

    Science.gov (United States)

    Parrado, Emilio A.; Kandel, William A.

    2010-01-01

    We analyze the relationship between Hispanic population growth and changes in U.S. rural income inequality from 1990 through 2000. Applying comparative approaches used for urban areas we disentangle Hispanic population growth's contribution to inequality by comparing and statistically modeling changes in the family income Gini coefficient across…

  4. [Population trends in Andorra and Monaco].

    Science.gov (United States)

    Lluelles, M J; Sanguin A-l

    1995-01-01

    Population trends in the micro-states of Andorra and Monaco are described and compared. The authors note that the population of Andorra has increased twelvefold since 1947 due to the development of a tax-free economy and a winter sports industry, whereas Monaco, on a much smaller territorial space, has remained relatively demographically stable. PMID:12156750

  5. Evolutionary factors affecting Lactate dehydrogenase A and B variation in the Daphnia pulex species complex

    Directory of Open Access Journals (Sweden)

    Cristescu Melania E

    2011-07-01

    Full Text Available Abstract Background Evidence for historical, demographic and selective factors affecting enzyme evolution can be obtained by examining nucleotide sequence variation in candidate genes such as Lactate dehydrogenase (Ldh. Two closely related Daphnia species can be distinguished by their electrophoretic Ldh genotype and habitat. Daphnia pulex populations are fixed for the S allele and inhabit temporary ponds, while D. pulicaria populations are fixed for the F allele and inhabit large stratified lakes. One locus is detected in most allozyme surveys, but genome sequencing has revealed two genes, LdhA and LdhB. Results We sequenced both Ldh genes from 70 isolates of these two species from North America to determine if the association between Ldh genotype and habitat shows evidence for selection, and to elucidate the evolutionary history of the two genes. We found that alleles in the pond-dwelling D. pulex and in the lake-dwelling D. pulicaria form distinct groups at both loci, and the substitution of Glutamine (S for Glutamic acid (F at amino acid 229 likely causes the electrophoretic mobility shift in the LDHA protein. Nucleotide diversity in both Ldh genes is much lower in D. pulicaria than in D. pulex. Moreover, the lack of spatial structuring of the variation in both genes over a wide geographic area is consistent with a recent demographic expansion of lake populations. Neutrality tests indicate that both genes are under purifying selection, but the intensity is much stronger on LdhA. Conclusions Although lake-dwelling D. pulicaria hybridizes with the other lineages in the pulex species complex, it remains distinct ecologically and genetically. This ecological divergence, coupled with the intensity of purifying selection on LdhA and the strong association between its genotype and habitat, suggests that experimental studies would be useful to determine if variation in molecular function provides evidence that LDHA variants are adaptive.

  6. Energy Systems and Population Health

    Energy Technology Data Exchange (ETDEWEB)

    Ezzati, Majid; Bailis, Rob; Kammen, Daniel M.; Holloway, Tracey; Price, Lynn; Cifuentes, Luis A.; Barnes, Brendon; Chaurey, Akanksha; Dhanapala, Kiran N.

    2004-04-12

    to rural and urban health facilities allows increased delivery and coverage of 3 various health services and interventions such as tests and treatments, better storage of medicine and vaccines, disinfection of medical equipment by boiling or radiation, and more frequent and efficient health system encounters through mobile clinics or longer working hours; and so on. In fact, while the dominant view of development-energy-health linkages has been that improvements in energy and health are outcomes of the socioeconomic development process (e.g., the ''energy ladder'' framework discussed below), it has even been argued that access to higher quality energy sources and technologies can initiate a chain of demographic, health, and development outcomes by changing the household structure and socioeconomic relationships. For example, in addition to increased opportunities for food and income production, reduced infant mortality as a result of transition to cleaner fuels or increased coverage of vaccination with availability of refrigerators in rural clinics may initiate a process of ''demographic transition'' to low-mortality and low-fertility populations (14). Such a transition has historically been followed with further improvements in maternal and child health and increased female participation in the labor markets and other economic activities.

  7. World population, human disaster, and nuclear holocaust.

    Science.gov (United States)

    Giddings, J C

    1973-09-01

    Too little attention is being paid to the theoretical mechanics of dealing with the optimum level of human population. Yet without such efforts, population goals are essentially meaningless and there is little incentive to curtail population growth. In an attempt to take a step in that direction, the author discusses a broad class of interrelated phenomena--consisting of various threats to human existence--that hinge strongly on population density. Then he develops simple conceptual models that provide a quantitative population dependence for various threats. These are always expressed as a simple power of population. Only threats of disasters that increase with an increase in population density are considered, eliminating most natural disasters. Threats of the 1st order, such as those from nuclear wastes and chemical pollutants, increase with an increase in population and a resultant increase in production. However, with increasing crowding and dependency upon high energy systems to provide basic resources, many 1st order threats can become threats of the 2nd of higher orders. The burial of nuclear wastes, for example, presents a threat of the 2nd order by affecting 1) the integrity of the geological formation at the burial site; and 2) the quantity of the radioactive material. As the relationship between population and interdependency strengthens, the crucial question will concern the stability of the independent networks; 1 error, due to human frailty or malice, can destroy a chain supplying food, energy, communications, or water. Into this system are thrown nuclear weapons, which, through human error or malice, could demolish the world. To illuminate some of the major elements of the nuclear threat, a model based on the threshold concept of nuclear armaments was created. This concept recognizes that any alliance of people possessing a minimum of technological and economic resources could build and deploy nuclear weapons. Most alliances will constitute no danger

  8. Curating Transient Population in Urban Dynamics System

    CERN Document Server

    Thakur, Gautam S; Stewart, Robert N; Urban, Marie L; Bhaduri, Budhendra L

    2016-01-01

    For past several decades, research efforts in population modelling has proven its efficacy in understanding the basic information about residential and commercial areas, as well as for the purposes of planning, development and improvement of the community as an eco-system. More or less, such efforts assume static nature of population distribution, in turn limited by the current ability to capture the dynamics of population change at a finer resolution of space and time. Fast forward today, more and more people are becoming mobile, traveling across borders impacting the nuts and bolts of our urban fabric. Unfortunately, our current efforts are being surpassed by the need to capture such transient population. It is becoming imperative to identify and define them, as well as measure their dynamics and interconnectedness. In this work, we intend to research urban population mobility patterns, gauge their transient nature, and extend our knowledge of their visited locations. We plan to achieve this by designing an...

  9. Generating synthetic baseline populations from register data

    DEFF Research Database (Denmark)

    Rich, Jeppe; Mulalic, Ismir

    2012-01-01

    algorithm. The solution strategy consists in establishing a harmonisation process for the population targets, which combined with a linear programming approach, is applied to generate a consistent target representation. The model approach is implemented and tested on Danish administrative register data. A......The paper presents a population synthesiser based on the method of Iterative Proportional Fitting (IPF) algorithm developed for the new Danish national transport model system. The synthesiser is designed for large population matrices and allows target variables to be represented in several target...... test on historical census data shows that a 2006 population could be predicted by a 1994 population with an overall percentage deviation of 5–6% given that targets were known. It is also indicated that the deviation is approximately a linear function of the length of the forecast period....

  10. Selection for mutational robustness in finite populations.

    Science.gov (United States)

    Forster, Robert; Adami, Christoph; Wilke, Claus O

    2006-11-21

    We investigate the evolutionary dynamics of a finite population of RNA sequences replicating on a neutral network. Despite the lack of differential fitness between viable sequences, we observe typical properties of adaptive evolution, such as increase of mean fitness over time and punctuated-equilibrium transitions, after initial mutation-selection balance has been reached. We find that a product of population size and mutation rate of approximately 30 or larger is sufficient to generate selection pressure for mutational robustness, even if the population size is orders of magnitude smaller than the neutral network on which the population resides. Our results show that quasispecies effects and neutral drift can occur concurrently, and that the relative importance of each is determined by the product of population size and mutation rate. PMID:16901510

  11. Statistical Dynamics of Regional Populations and Economies

    CERN Document Server

    Huo, Jie; Hao, Rui; Wang, Peng

    2016-01-01

    A practical statistical analysis on the regional populations and GDPs of China is conducted. The result shows that the distribution of the populations and that of the GDPs obeys the shifted power law, respectively. To understand these characteristics, a generalized Langevin equation describing variation of population is proposed based on the correlation between population and GDP as well as the random fluctuations of the related factors. The equation is transformed into the Fokker-Plank equation, and the solution demonstrates a transform of population distribution from the normal Gaussian distribution to a shifted power law. It also suggests a critical point of time at which the transform occurs. The shifted power law distribution in the supercritical situation is qualitatively in accordance with the practical result. The distribution of the GDPs is derived based on the Cobb-Douglas production function, and presents a change from a shifted power law to the Gaussian distribution. This result indicates that the...

  12. Cryptic function loss in animal populations.

    Science.gov (United States)

    McConkey, Kim R; O'Farrill, Georgina

    2015-04-01

    The essential functional roles performed by animal species are lost when they become locally extinct, and ecosystems are critically threatened by this decline in functional diversity. Theory that links function, diversity, and ecosystem stability exists but fails to assess function loss that occurs in species with persistent populations. The entire functional role of a species, or a critical component of it, can be lost following large population declines (functional extinction), following population increase, or after behavioural adaptations to changes in the population, community, habitat, or climate. Here, we provide a framework that identifies the scenarios under which 'cryptic' function loss can occur in persistent populations. Cryptic function loss is potentially widespread and critically threatens ecosystem stability across the globe. PMID:25678379

  13. STUDY ON HARVESTED POPULATION WITH DIFFUSIONAL MIGRATION

    Institute of Scientific and Technical Information of China (English)

    FAN Meng; WANG Ke; ZHANG Yujuan; ZHANG Shuwen; LIU Huimin

    2001-01-01

    This paper is devoted to the study of the dynamical behavior and harvesting problem of an exploited population with diffusional migration, for which a protective patch is established. We examine the effects of protective patch and harvest on the population resources and conclude that the protective patch is effective for the conservation of population resources and ecological environment, though in some cases the extinction can not be eliminated. The dangerous region, the parameters domains and the typical bifurcation curves of stability of steady states for the considered system are determined. The optimal harvest policy for the considered population is made also. The explicit expressions are obtained for the optimal harvesting effort, the maximum sustainable yield and the corresponding population density. Our results provide a theoretical evidence for the practical management of biological resources.

  14. Copy number variation across European populations.

    Directory of Open Access Journals (Sweden)

    Wanting Chen

    Full Text Available Genome analysis provides a powerful approach to test for evidence of genetic variation within and between geographical regions and local populations. Copy number variants which comprise insertions, deletions and duplications of genomic sequence provide one such convenient and informative source. Here, we investigate copy number variants from genome wide scans of single nucleotide polymorphisms in three European population isolates, the island of Vis in Croatia, the islands of Orkney in Scotland and the South Tyrol in Italy. We show that whereas the overall copy number variant frequencies are similar between populations, their distribution is highly specific to the population of origin, a finding which is supported by evidence for increased kinship correlation for specific copy number variants within populations.

  15. Promoting Physical Activity among Underserved Populations.

    Science.gov (United States)

    Mendoza-Vasconez, Andrea S; Linke, Sarah; Muñoz, Mario; Pekmezi, Dori; Ainsworth, Cole; Cano, Mayra; Williams, Victoria; Marcus, Bess H; Larsen, Britta A

    2016-01-01

    Underserved populations, including racial/ethnic minorities, individuals with low socioeconomic status, and individuals with physical disabilities, are less likely to engage in sufficient moderate to vigorous physical activity (MVPA) and are thus at increased risk of morbidity and mortality. These populations face unique challenges to engaging in MVPA. Learning how to overcome these challenges is a necessary first step in achieving health equity through health promotion research. In this review of the literature, we discuss issues and strategies that have been used to promote MVPA among individuals from underserved populations, focusing on recruitment, intervention delivery, and the use of technology in interventions. Physical activity promotion research among these vulnerable populations is scarce. Nevertheless, there is preliminary evidence of efficacy in the use of certain recruitment and intervention strategies including tailoring, cultural adaptation, incorporation of new technologies, and multilevel and community-based approaches for physical activity promotion among different underserved populations. PMID:27399827

  16. Hemochromatosis mutations in the general population

    DEFF Research Database (Denmark)

    Andersen, Rolf Vaern; Tybjaerg-Hansen, Anne; Appleyard, Merete;

    2004-01-01

    The progression rate of iron overload in hereditary hemochromatosis in individuals in the general population is unknown. We therefore examined in the general population iron overload progression rate in C282Y homozygotes. Using a cohort study of the Danish general population, The Copenhagen City...... saturation and ferritin levels increased slightly in male and female C282Y homozygotes. None of the C282Y homozygotes developed clinically overt hemochromatosis. In conclusion, individuals in the general population with C282Y homozygosity at most demonstrate modest increases in transferrin saturation...... and ferritin levels, and clinically overt hemochromatosis is rare. Therefore, C282Y homozygotes identified during population screening, and not because of clinically overt hemochromatosis, at most need to be screened for manifestations of hemochromatosis every 10 to 20 years....

  17. Great ape genetic diversity and population history

    DEFF Research Database (Denmark)

    Prado-Martinez, Javier; Sudmant, Peter H.; Kidd, Jeffrey M.;

    2013-01-01

    Most great ape genetic variation remains uncharacterized; however, its study is critical for understanding population history, recombination, selection and susceptibility to disease. Here we sequence to high coverage a total of 79 wild- and captive-born individuals representing all six great ape...... species and seven subspecies and report 88.8 million single nucleotide polymorphisms. Our analysis provides support for genetically distinct populations within each species, signals of gene flow, and the split of common chimpanzees into two distinct groups: Nigeria-Cameroon/western and central....../eastern populations. We find extensive inbreeding in almost all wild populations, with eastern gorillas being the most extreme. Inferred effective population sizes have varied radically over time in different lineages and this appears to have a profound effect on the genetic diversity at, or close to, genes in almost...

  18. Institutional impediments to population policy in Australia.

    Science.gov (United States)

    Mcnicoll, G

    1995-11-01

    Despite having almost the highest rate of population growth among OECD countries, Australia has no explicit population policy. The potential elements of such a policy, especially with regard to immigration, family, and environment, are deeply entrenched in separate political domains and responsive to separate clusters of interests. Vague, demographically ill-informed, and mutually inconsistent views of a desired population size or trajectory for Australia co-exist, with no arena for any systematic engagement and considered debate among them. Parallels to the case of Australia can be drawn with Canada and the US. Population policy may well be one of the issues that modern liberal democracies find particularly difficult to manage. There are, however, also specific historical circumstances which led to the outcome and perpetuate the situation. Population processes and the institution of citizenship, and contested policy domains are discussed. PMID:12321981

  19. Possible ancestral structure in human populations.

    Directory of Open Access Journals (Sweden)

    Vincent Plagnol

    2006-07-01

    Full Text Available Determining the evolutionary relationships between fossil hominid groups such as Neanderthals and modern humans has been a question of enduring interest in human evolutionary genetics. Here we present a new method for addressing whether archaic human groups contributed to the modern gene pool (called ancient admixture, using the patterns of variation in contemporary human populations. Our method improves on previous work by explicitly accounting for recent population history before performing the analyses. Using sequence data from the Environmental Genome Project, we find strong evidence for ancient admixture in both a European and a West African population (p approximately 10(-7, with contributions to the modern gene pool of at least 5%. While Neanderthals form an obvious archaic source population candidate in Europe, there is not yet a clear source population candidate in West Africa.

  20. Common bunt resistant wheat composite cross populations

    DEFF Research Database (Denmark)

    Steffan, Philipp Matthias; Borgen, A.; Backes, Gunter Martin;

    Utilising diverse populations instead of genetically homogeneous varieties is expected to lead to a number of advantages in cereal production. These include reduced epidemics of plant diseases, improved weed competition and better exploitation of soil nutrients, resulting in improved yield...... that the highest benefits of utilizing diverse populations can be achieved. BIOBREED focuses on three main aspects of wheat population breeding for organic and low input production systems: i) common bunt (caused by Tilletia caries) resistance, ii) selection for improved protein content and iii) the influence...... stability. However, a number of challenges must be met before diverse wheat populations can be introduced into commercial wheat production: one of these is the development of breeding technologies based on mass selection which enable breeders and farmers to improve specific traits in populations...

  1. Oral medicine and the ageing population.

    Science.gov (United States)

    Yap, T; McCullough, M

    2015-03-01

    The oral cavity is subject to age related processes such as cellular ageing and immunosenescence. The ageing population bears an increased burden of intraoral pathology. In oral medicine, the majority of presenting patients are in their fifth to seventh decade of life. In this review, we discuss the ageing population's susceptibility to mucosal disorders and the increased prevalence of potentially malignant disorders and oral squamous cell carcinoma, as well as dermatoses including oral lichen planus and immunobullous conditions. We also address the ageing population's susceptibility to oral discomfort and explore salivary secretion, ulceration and the symptoms of oral burning. Finally, we will describe orofacial pain conditions which are more likely encountered in an older population. This update highlights clinical presentations which are more likely to be encountered in the ageing population in a general practice setting and the importance of screening both new and long-term patients.

  2. A few problems concerning population science.

    Science.gov (United States)

    Xu, D

    1981-05-27

    This paper discusses problems concerning population science in China within a Marxist perspective. In contrast to capitalism, the socialist society is built on the foundation of the socialist public ownership of the means of production. The socialist law of population, as distinct from the capitalist, means the inevitability of population planning under the socialist mode of production. If rapid population growth is allowed to continue, the yearly increment of material wealth will be conserved by the additional population which will thereby nullify the cultural and material needs of the people. Therefore, population growth planning is necessary to control reproduction and material production as well as the development of the national economy. 3 differences between Chinese population theory and that of the neoMalthusians are discussed: 1) whereas the neoMalthusians propose to safeguard the capitalist system, the Chinese theory is to consolidate the socialist system, 2) Malthusianism emphasizes population growth and ignores, unlike the Chinese system, the possibility of increasing production while achieving population control by degrees, and 3) responsibility for controlling "surplus population" is placed on the working people by neoMalthusians but on the elites in the Chinese system. Recent efforts in China are to control the population by reducing families to one child. In the past 30 years, a series of contradictions have developed in the development of the economy in relation to population growth: 1) distinct disproportion arises between the growth of the total population (66.7% between 1952-78) and that of the means of subsistence (5.4%/year between 1952-78); 2) if population growth is not controlled, a contradiction will occur between those of working ages and the growth of the means of production; and 3) the disproportion between the quality of population and the needs of the modern socialist system. Under the socialist system, population control is

  3. Match probabilities in racially admixed populations.

    Science.gov (United States)

    Lange, K

    1993-02-01

    The calculation of match probabilities is the most contentious issue dividing prosecution and defense experts in the forensic applications of DNA fingerprinting. In particular, defense experts question the applicability of the population genetic laws of Hardy-Weinberg and linkage equilibrium to racially admixed American populations. Linkage equilibrium justifies the product rule for computing match probabilities across loci. The present paper suggests a method of bounding match probabilities that depends on modeling gene descent from ancestral populations to contemporary populations under the assumptions of Hardy-Weinberg and linkage equilibrium only in the ancestral populations. Although these bounds are conservative from the defendant's perspective, they should be small enough in practice to satisfy prosecutors.

  4. Population developmental stage determines the recovery potential of Daphnia magna populations after fenvalerate application.

    Science.gov (United States)

    Pieters, Barry J; Liess, Matthias

    2006-10-01

    This study investigated the responses of Daphnia magna populations to pulsed exposures of the pyrethroid insecticide Fenvalerate applied during an early and a late stage of population development, and analyzed the dynamics of the subsequent recovery. A novel digital observation technique was used to describe the size and numbers of animals. High Fenvalerate concentrations caused high mortality rates during exponential population growth as well as during the food-limited stationary phase. However, recovery of populations took considerably longer in the stationary phase than in populations growing exponentially. The poor nutritional and reproductive state of food-deprived adults was indicated as the main cause of the slow recovery of populations. It is argued that populations operating at the carrying capacity of their environment are vulnerable to toxicant-induced disturbances to an extent not predictable from observations on exponentially growing populations such as are commonly used in ecotoxicology. PMID:17051815

  5. Discussion of Population Modernization Theory and Actuality Analysis of Population Modernization in China

    Institute of Scientific and Technical Information of China (English)

    Wang Shu

    2004-01-01

    This paper discusses the basic concept and connotation of population modernization.The author briefly analyzes the actuality of population modernization in China, gives some advice and puts forward some measures.

  6. Declaration of the Population Policy [April 1988].

    Science.gov (United States)

    1989-01-01

    The Declaration of the Population Policy, Ministry of Planning and Cooperation, Directorate of Human Resources, 1988, of Senegal begins with the basic principles of the population policy. The intervention by the State into "individual" problems is justified by the Constitution authorizing concrete action in all areas of national life, including population and family life, where the social and economic improvement of Senegal and the entire African continent rests. The population policy takes into account demographic, economic, social, and cultural factors, as well as respect for the fundamental rights of individual persons, the necessity of preserving the family unit, and respect for the rights of individuals and couples to choose the size of their family and to control their fertility. The policy's objectives are defined and include the reduction of morbidity and mortality rates, particularly among mothers and infants, by instituting maternal-child health programs, including family planning. While it would be premature to determine quantitative demographic objectives, reviewing demographic perspectives can clarify future choices, and tables are provided. Section 3.3 defines the following population policy strategies: maternal-child health; fertility and birth spacing; promotion of women (status of women); promotion of youth; promotion of the elderly; preservation of the family; migration, urbanization, and management of territory; employment; studies and research (on population, fertility, demographic and health, infant mortality, and a general population census); information, education, and communication on the population issues; and legislative measures and regulation. The institutional framework will be advanced through the efforts of several kinds of specified institutions, among them: The Interministerial Council on Population, presided over by the Head of States; the National Population Commission; the Directorate of Human Resources; the Ministry of Public

  7. Five proposals re China's population growth control.

    Science.gov (United States)

    Liu, Z; Wu, C; Lin, F

    1983-01-01

    China's population was 540 million in 1949. By the end of 1978 the population will reach 960 million, representing a 2% average annual growth rate. High population growth 1) is costly, 2) makes finding employment difficult, since there is little still land still to be reclaimed and agricultural productivity cannot be upgraded if backward farming techniques are used simply to employ more people, and 3) reduces the quality of material and cutural life. Nearly half of consumer funds accumulated in 1949-1977 was spent to provide basic needs for China's 600 million people. Housing has especially suffered: average per capita living space is only 2 square meters in some cities. With over 100 million primary school children and tens of millions in secondary schools, education funds must be allocated to the lower grades, to higher education's detriment. Each generation's age structure determines the next generation's reproduction scale and speed. This historical principle leads to the following: 1) population growth will continue to be vigorous given growth at a 2% rate, or if a percentage of rural (30%) and urban (10%) couples continue to have more than 2 children, or if every couple only has 2 children; 2) population stagnation requires continuous, persistent efforts, abolishing 2 or more children and encouraging one child per couple. Stagnation can be reached by 2008, with 1,200 million people. Political and ideological education combined with effective economic measures must solve the population problem. 5 strong measures must be taken: 1) economic policies and incentives should assist couples with one or no child, 2) every means should be used to communicate the population problem to the people, 3) population control should be part of the national economy program, 4) 3 births should be prohibited and one child per couple advocated, and 5) a permanent "population committee" should be established to insure ongoing population programs, policies, study, and evaluation

  8. [Policies of economic development and population].

    Science.gov (United States)

    Aleman, J L

    1974-01-01

    This literature review attempts to evaluate critically the theoretical and empirical evidence regarding the relationship between development policies and population and to assess the logical coherence of the principal types of population policy as they relate to economic development. The 1st part, on the relationship between economic development and population growth, consists of 5 sections which discuss: 1) the theories of classical economists including Quesnay, Malthus, Pareto, Marshall, and Pigou; 2) attempts to correlate population growth and economic development in developed countries by Kuznets and in developing countries by Adelman, Weintraub, Heer, Kirk, and others; 3) macroeconomic arguments used to defend aggressive policies of population control, including the scarcity of natural resources, the difficulty of increasing the rates of savings and investment with growing populations, and the disadvantages of rural-urban migration; 4) economic analyses of the desire to limit births which view children as either producer or consumer goods; and 5) the influence of economic development on social structure as it relates to the demand for children. In the 2nd part, 3 principal "ideal types" of population and economic development policy are identified: policies oriented toward growth of the modern sector of the economy, policies oriented toward population control, and policies oriented toward income distribution and education. The assumptions, mode of action, probabilities of success and limitations of each strategy are assessed. It is concluded that neither development of the modern sector alone nor attempts to promote birth control alone are sufficient to curb population growth appreciably. A concentrated policy to develop the most backward sectors of the economy might be the most likely to lead to a significant slowing of population growth but such a policy is unlikely to be tolerated by the wealthier classes in the absence of extreme coercion. A combination of

  9. In-depth study of Marxist population theory, promote China's population science.

    Science.gov (United States)

    Liu, J

    1983-01-01

    The 3rd National Population Science Seminar, held in Beijng from Feb. 21-27, 1981, brought together over 270 Chinese population researchers and professionals, as well as social science and family planning workers. Participants presented over 220 papers and reports, which showed a higher level of scholarship than previous seminar papers. Chen Dau, the head of the Planning Bureau of the Chinese Academy for Social Sciences, gave the opening address and explained the seminar's 2 tasks: 1) to exchange academic ideas and 2) to found the Population Association of China (PAC), and suggested 3 topics for theoretical discussion: 1) Marxist theory on the 2 kinds of production, 2) the differences between China's population control and old and NeoMalthusianism, and 3) the 1 child policy. Xu Dixin, the vice-president of the Chinese Academy of Social Sciences, spoke on socialist population laws, planned population control, and potential problems with the 1 child family policy. 8 special groups at the seminar discussed 1) Marxist theory on the 2 types of production, 2) Marx and Malthus on population, 3) China's population control policy, 4) population studies, 5) China's population problems, 6) problems with population control in rural areas, 7) urban population issues, and 8) the population problems of minority nationalities. Participants founded the PAC on the last day of the seminar. Vice-premier Cheu Muhua also addressed the seminar on the tremendous success the family planning program has had in the last 2 years and the difficulty of the task of controlling China's population growth. Population research must explain China's population laws so that growth can be controlled. PMID:12313987

  10. Impact of Population Stratification on Family-Based Association in an Admixed Population

    OpenAIRE

    Mersha, T. B.; Ding, L; He, H; Alexander, E. S.; Zhang, X.; B. G. Kurowski; Pilipenko, V.; Kottyan, L.; Martin, L. J.; Fardo, D. W.

    2015-01-01

    Population substructure is a well-known confounder in population-based case-control genetic studies, but its impact in family-based studies is unclear. We performed population substructure analysis using extended families of admixed population to evaluate power and Type I error in an association study framework. Our analysis shows that power was improved by 1.5% after principal components adjustment. Type I error was also reduced by 2.2% after adjusting for family substratification. The prese...

  11. 40 CFR 68.30 - Defining offsite impacts-population.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Defining offsite impacts-population... impacts—population. (a) The owner or operator shall estimate in the RMP the population within a circle... defined in § 68.22(a). (b) Population to be defined. Population shall include residential population....

  12. 10 CFR 100.11 - Determination of exclusion area, low population zone, and population center distance.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Determination of exclusion area, low population zone, and population center distance. 100.11 Section 100.11 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) REACTOR... and for Testing Reactors § 100.11 Determination of exclusion area, low population zone, and...

  13. Confidence interval for number of population in dynamical stochastic exponential population growth models

    Directory of Open Access Journals (Sweden)

    Morteza Khodabin

    2013-06-01

    Full Text Available In this paper, the confidence interval for the solution of stochastic exponential population growth model where the so-called parameter, population growth rate is not completely definite and it depends on some random environmental effects is obtained. We use Iran population data in the period 1921-2006 as an example.

  14. Community development NGOs and the population issue.

    Science.gov (United States)

    Morales H

    1994-01-01

    Policymakers and institutions of the more developed Northern countries make cogent arguments for a reduction in global population growth and an eventual stabilization of population size. Current global population is simply too large for the Earth's current carrying capacity and level of technology. Should world population double, insecurity and scarcity will result. The author, however, counters that population, in all of its dimensions, is neither an issue nor problem exclusive of and to the South. Population growth and related dynamics are instead a concern and responsibility for all people on Earth. The Northern call for population reduction is self-centered in its ignorance of equity, poverty, indebtedness, and structural adjustment program-induced collapse of social security systems; these latter issues are of greater concern than population growth to the developing countries of the South. Northern priority on population also directly affects resource allocation such that more funds are available for population activities than for mechanisms such as the Global Environmental Facility. True, industrial societies have kept their population sizes at manageable levels. For how long, however, can developed countries expect to maintain their annual per capita incomes of more than $20,000 and annual per capita waste emission of more than 20 tons on the backs of hundreds of millions of people in other parts of the world? Developed country lifestyles are ultimately unsustainable. Nongovernmental organizations and voluntary citizens' groups in the North need to help Southern nations and communities by focusing upon the interlocking relationship between the lifestyle in the North and the South's problems of poverty, environmental degradation, and erosion of community and social cohesion. Northern citizens' groups can complement the efforts of their Southern counterparts by advocating a new kind of structural adjustment which reverses the pattern of resource outflow from

  15. Population growth and environmental degradation in Malawi.

    Science.gov (United States)

    Kalipeni, E

    1992-01-01

    Malawi has been ranked by the World Bank as one of the poorest countries in Africa. Malawi's only resources are its people and fertile soil, which comprises about 55% of land area. Environmental degradation and population growth conditions in Malawi were used to illustrate the model of environmental degradation linked to population pressure on land resources and government development strategies that favored large-scale agricultural farms. The result has been deforestation, overgrazing, overuse of land for subsistence, and increased population density. The argument was that population growth in some developing countries has been so rapid that environmental collapse is the result. The theoretical framework linking population growth, environment, and resources emphasized processes: 1) the precursor stage of underlying causes; 2) the problem phase with potential ecological and economic decline; and 3) consequences (environmental decline, reduction in food production systems, and reduction in standard of living). The precursors were identified as an agrarian society, lack of a population policy, and emphasis on large families. The problems were rapid population growth and immigration from Mozambique, which led to increased demand for trees for fuel and consequent deforestation, increased demand for arable land and consequent landlessness, increased investment in livestock and consequent overgrazing, and continued population momentum which was a financial burden to government and resulted in increased labor competition. The ecological consequences were soil erosion, degradation of vegetation, and water supply contamination and decline. Eventually, famines will occur and lead to disease, migration, deserted villages, urbanization, unemployment, ethnic conflicts, and political unrest. Population was estimated at 8.75 million in 1990, with exponential growth expected. Completed family size was 6.6 children per woman. Even replacement fertility would mean growth for 50 more

  16. Population Genomics of Fungal and Oomycete Pathogens.

    Science.gov (United States)

    Grünwald, Niklaus J; McDonald, Bruce A; Milgroom, Michael G

    2016-08-01

    We are entering a new era in plant pathology in which whole-genome sequences of many individuals of a pathogen species are becoming readily available. Population genomics aims to discover genetic mechanisms underlying phenotypes associated with adaptive traits such as pathogenicity, virulence, fungicide resistance, and host specialization, as genome sequences or large numbers of single nucleotide polymorphisms become readily available from multiple individuals of the same species. This emerging field encompasses detailed genetic analyses of natural populations, comparative genomic analyses of closely related species, identification of genes under selection, and linkage analyses involving association studies in natural populations or segregating populations resulting from crosses. The era of pathogen population genomics will provide new opportunities and challenges, requiring new computational and analytical tools. This review focuses on conceptual and methodological issues as well as the approaches to answering questions in population genomics. The major steps start with defining relevant biological and evolutionary questions, followed by sampling, genotyping, and phenotyping, and ending in analytical methods and interpretations. We provide examples of recent applications of population genomics to fungal and oomycete plant pathogens. PMID:27296138

  17. Morphological Variation among 23 Xiphinema americanum Populations.

    Science.gov (United States)

    Cho, M R; Robbins, R T

    1991-01-01

    Morphometrics of 23 United States populations of Xiphinema americanum sensu lato, sharing the characteristics of an offset lip region and conoid tail, were examined and analyzed statistically by canonical discriminant analysis (CDA). Specimens were collected from Arkansas, Georgia, Tennessee, Mississippi, Florida, Oklahoma, California, and North Dakota. Eleven measurements and body ratios obtained from female specimens were used in the analysis. Xiphinema americanum, X. bricolensis, X. californicum, X. citricolum, X, intermedium, X. tarjanense, and X. thornei, and one undescribed species were identified among the 23 populations. Three groups -- X. americanum-group, X. californicum-group, and X. intermedium-group (X. intermedium and X. tarjanense) -- were formed and four populations belonging to four different species were separated consistently from these groups in CDA scatterplots of the 23 populations. Composition of the groups was somewhat related to the geographical origins of the populations in the groups. A population from California had morphometrics intermediate between X. americanum and X. californicum. Separation between the X. americanum-group and X. californicum-group in the CDA scatterplots was not as distinct as that between them and the X. intermedium-group or between any of the three groups and the four single outlying populations.

  18. Host plant adaptation in Drosophila mettleri populations.

    Science.gov (United States)

    Castrezana, Sergio; Bono, Jeremy M

    2012-01-01

    The process of local adaptation creates diversity among allopatric populations, and may eventually lead to speciation. Plant-feeding insect populations that specialize on different host species provide an excellent opportunity to evaluate the causes of ecological specialization and the subsequent consequences for diversity. In this study, we used geographically separated Drosophila mettleri populations that specialize on different host cacti to examine oviposition preference for and larval performance on an array of natural and non-natural hosts (eight total). We found evidence of local adaptation in performance on saguaro cactus (Carnegiea gigantea) for populations that are typically associated with this host, and to chemically divergent prickly pear species (Opuntia spp.) in a genetically isolated population on Santa Catalina Island. Moreover, each population exhibited reduced performance on the alternative host. This finding is consistent with trade-offs associated with adaptation to these chemically divergent hosts, although we also discuss alternative explanations for this pattern. For oviposition preference, Santa Catalina Island flies were more likely to oviposit on some prickly pear species, but all populations readily laid eggs on saguaro. Experiments with non-natural hosts suggest that factors such as ecological opportunity may play a more important role than host plant chemistry in explaining the lack of natural associations with some hosts. PMID:22493678

  19. Host plant adaptation in Drosophila mettleri populations.

    Directory of Open Access Journals (Sweden)

    Sergio Castrezana

    Full Text Available The process of local adaptation creates diversity among allopatric populations, and may eventually lead to speciation. Plant-feeding insect populations that specialize on different host species provide an excellent opportunity to evaluate the causes of ecological specialization and the subsequent consequences for diversity. In this study, we used geographically separated Drosophila mettleri populations that specialize on different host cacti to examine oviposition preference for and larval performance on an array of natural and non-natural hosts (eight total. We found evidence of local adaptation in performance on saguaro cactus (Carnegiea gigantea for populations that are typically associated with this host, and to chemically divergent prickly pear species (Opuntia spp. in a genetically isolated population on Santa Catalina Island. Moreover, each population exhibited reduced performance on the alternative host. This finding is consistent with trade-offs associated with adaptation to these chemically divergent hosts, although we also discuss alternative explanations for this pattern. For oviposition preference, Santa Catalina Island flies were more likely to oviposit on some prickly pear species, but all populations readily laid eggs on saguaro. Experiments with non-natural hosts suggest that factors such as ecological opportunity may play a more important role than host plant chemistry in explaining the lack of natural associations with some hosts.

  20. Principal components analysis of population admixture.

    Directory of Open Access Journals (Sweden)

    Jianzhong Ma

    Full Text Available With the availability of high-density genotype information, principal components analysis (PCA is now routinely used to detect and quantify the genetic structure of populations in both population genetics and genetic epidemiology. An important issue is how to make appropriate and correct inferences about population relationships from the results of PCA, especially when admixed individuals are included in the analysis. We extend our recently developed theoretical formulation of PCA to allow for admixed populations. Because the sampled individuals are treated as features, our generalized formulation of PCA directly relates the pattern of the scatter plot of the top eigenvectors to the admixture proportions and parameters reflecting the population relationships, and thus can provide valuable guidance on how to properly interpret the results of PCA in practice. Using our formulation, we theoretically justify the diagnostic of two-way admixture. More importantly, our theoretical investigations based on the proposed formulation yield a diagnostic of multi-way admixture. For instance, we found that admixed individuals with three parental populations are distributed inside the triangle formed by their parental populations and divide the triangle into three smaller triangles whose areas have the same proportions in the big triangle as the corresponding admixture proportions. We tested and illustrated these findings using simulated data and data from HapMap III and the Human Genome Diversity Project.

  1. Population estimation techniques for routing analysis

    International Nuclear Information System (INIS)

    A number of on-site and off-site factors affect the potential siting of a radioactive materials repository at Yucca Mountain, Nevada. Transportation related issues such route selection and design are among them. These involve evaluation of potential risks and impacts, including those related to population. Population characteristics (total population and density) are critical factors in the risk assessment, emergency preparedness and response planning, and ultimately in route designation. This paper presents an application of Geographic Information System (GIS) technology to facilitate such analyses. Specifically, techniques to estimate critical population information are presented. A case study using the highway network in Nevada is used to illustrate the analyses. TIGER coverages are used as the basis for population information at a block level. The data are then synthesized at tract, county and state levels of aggregation. Of particular interest are population estimates for various corridor widths along transport corridors -- ranging from 0.5 miles to 20 miles in this paper. A sensitivity analysis based on the level of data aggregation is also presented. The results of these analysis indicate that specific characteristics of the area and its population could be used as indicators to aggregate data appropriately for the analysis

  2. POPREP: a generic report for population management.

    Science.gov (United States)

    Groeneveld, E; Westhuizen, B v D; Maiwashe, A; Voordewind, F; Ferraz, J B S

    2009-01-01

    Genetic variation provides a basis upon which populations can be genetically improved. Management of animal genetic resources in order to minimize loss of genetic diversity both within and across breeds has recently received attention at different levels, e.g., breed, national and international levels. A major need for sustainable improvement and conservation programs is accurate estimates of population parameters, such as rate of inbreeding and effective population size. A software system (POPREP) is presented that automatically generates a typeset report. Key parameters for population management, such as age structure, generation interval, variance in family size, rate of inbreeding, and effective population size form the core part of this report. The report includes a default text that describes definition, computation and meaning of the various parameters. The report is summarized in two pdf files, named Population Structure and Pedigree Analysis Reports. In addition, results (e.g., individual inbreeding coefficients, rate of inbreeding and effective population size) are stored in comma-separate-values files that are available for further processing. Pedigree data from eight livestock breeds from different species and countries were used to describe the potential of POPREP and to highlight areas for further research. PMID:19866435

  3. Familial versus mass selection in small populations

    Directory of Open Access Journals (Sweden)

    Couvet Denis

    2003-07-01

    Full Text Available Abstract We used diffusion approximations and a Markov-chain approach to investigate the consequences of familial selection on the viability of small populations both in the short and in the long term. The outcome of familial selection was compared to the case of a random mating population under mass selection. In small populations, the higher effective size, associated with familial selection, resulted in higher fitness for slightly deleterious and/or highly recessive alleles. Conversely, because familial selection leads to a lower rate of directional selection, a lower fitness was observed for more detrimental genes that are not highly recessive, and with high population sizes. However, in the long term, genetic load was almost identical for both mass and familial selection for populations of up to 200 individuals. In terms of mean time to extinction, familial selection did not have any negative effect at least for small populations (N ≤ 50. Overall, familial selection could be proposed for use in management programs of small populations since it increases genetic variability and short-term viability without impairing the overall persistence times.

  4. POPREP: a generic report for population management.

    Science.gov (United States)

    Groeneveld, E; Westhuizen, B v D; Maiwashe, A; Voordewind, F; Ferraz, J B S

    2009-09-29

    Genetic variation provides a basis upon which populations can be genetically improved. Management of animal genetic resources in order to minimize loss of genetic diversity both within and across breeds has recently received attention at different levels, e.g., breed, national and international levels. A major need for sustainable improvement and conservation programs is accurate estimates of population parameters, such as rate of inbreeding and effective population size. A software system (POPREP) is presented that automatically generates a typeset report. Key parameters for population management, such as age structure, generation interval, variance in family size, rate of inbreeding, and effective population size form the core part of this report. The report includes a default text that describes definition, computation and meaning of the various parameters. The report is summarized in two pdf files, named Population Structure and Pedigree Analysis Reports. In addition, results (e.g., individual inbreeding coefficients, rate of inbreeding and effective population size) are stored in comma-separate-values files that are available for further processing. Pedigree data from eight livestock breeds from different species and countries were used to describe the potential of POPREP and to highlight areas for further research.

  5. What population studies can do for business.

    Science.gov (United States)

    Hugo, G

    1991-05-01

    This paper examines how specific skills essential to demography, the scientific study of human populations, can be useful in private and public sector planning. Over the past 2 decades, Australia's population has undergone profound transformations -- a shift to below replacement level fertility and a change in ethnic composition, to name a few. And these changes have reshaped the markets for goods, services, and labor. Because demography seeks to analyze and explain changes in the size, composition, and spatial distribution of people, this discipline requires certain skills that can be particularly valuable to both private and public sector planning. These skills include: 1) a sound knowledge of why and how populations change over time; 2) a wide range of concepts (the "cohort," for example) which allow demographers to analyze the dynamics of change in a population; 3) statistical techniques; and 4) life tables techniques. Having named the specific skills of demographers, the author identifies the areas of business and public administration where these skills can be most useful, areas that include the following: strategic long-term planning, marketing, market segmentation, small area analysis, household and family level analysis, projections and estimates, human resources analysis, and international population trends. Finally, the author discusses the implications of applied population analysis on the training of demographers in Australia, emphasizing the role of the Australian Population Association in improving the status of demography as an important planning tool.

  6. Population planning policy in the Philippines.

    Science.gov (United States)

    Flavier, J M

    1973-01-01

    Population policy of the Philippine government is discussed in its evolution, current status under the 1973 constitution, and future development. Despite the low income, strong family ties, 7000 islands, 87 languages and 82% Catholic population, the Philippines has an official population policy which evolved into the Population Commission in 1969. The commission recommended setting goals, furthering education, removing legal drawbacks, reducing mortality, regulating internal migration and coordinating public and private international funding organizations. The private organizations, international funding,mass media, academic influence, and possibly the Catholic hierarchy influenced events positively. During martial law (September 1972 to January 1973) the government took on responsibility to require licensed professionals to learn family planning, and to change tax exemptions. The constitution now states that the State must achieve a population level conducive to national welfare. The present policy considers population planning an economic priority, has placed 5 cabinet members on the board of the Population Commission (no representatives from private organizations, which recruit 70% of acceptors), and has an extremely optimistic 5 year plan. No public protest had emerged, and because rhythm is included, it is hoped that rhythm users well eventually change to effective methods. Foreign assistance will be needed, and is channeled through the National Economic and Development Authority. Future needs include paramidics, nonclinical methods, rural access, incentives for program workers, and more effective propaganda.

  7. Mathematical Modeling of Extinction of Inhomogeneous Populations.

    Science.gov (United States)

    Karev, G P; Kareva, I

    2016-04-01

    Mathematical models of population extinction have a variety of applications in such areas as ecology, paleontology and conservation biology. Here we propose and investigate two types of sub-exponential models of population extinction. Unlike the more traditional exponential models, the life duration of sub-exponential models is finite. In the first model, the population is assumed to be composed of clones that are independent from each other. In the second model, we assume that the size of the population as a whole decreases according to the sub-exponential equation. We then investigate the "unobserved heterogeneity," i.e., the underlying inhomogeneous population model, and calculate the distribution of frequencies of clones for both models. We show that the dynamics of frequencies in the first model is governed by the principle of minimum of Tsallis information loss. In the second model, the notion of "internal population time" is proposed; with respect to the internal time, the dynamics of frequencies is governed by the principle of minimum of Shannon information loss. The results of this analysis show that the principle of minimum of information loss is the underlying law for the evolution of a broad class of models of population extinction. Finally, we propose a possible application of this modeling framework to mechanisms underlying time perception. PMID:27090117

  8. Genetic drift of HIV populations in culture.

    Directory of Open Access Journals (Sweden)

    Yegor Voronin

    2009-03-01

    Full Text Available Populations of Human Immunodeficiency Virus type 1 (HIV-1 undergo a surprisingly large amount of genetic drift in infected patients despite very large population sizes, which are predicted to be mostly deterministic. Several models have been proposed to explain this phenomenon, but all of them implicitly assume that the process of virus replication itself does not contribute to genetic drift. We developed an assay to measure the amount of genetic drift for HIV populations replicating in cell culture. The assay relies on creation of HIV populations of known size and measurements of variation in frequency of a neutral allele. Using this assay, we show that HIV undergoes approximately ten times more genetic drift than would be expected from its population size, which we defined as the number of infected cells in the culture. We showed that a large portion of the increase in genetic drift is due to non-synchronous infection of target cells. When infections are synchronized, genetic drift for the virus is only 3-fold higher than expected from its population size. Thus, the stochastic nature of biological processes involved in viral replication contributes to increased genetic drift in HIV populations. We propose that appreciation of these effects will allow better understanding of the evolutionary forces acting on HIV in infected patients.

  9. [Population policy: substantial but insufficient advances].

    Science.gov (United States)

    Rodriguez Y Gonzalez, A

    1988-01-01

    Population policy was revised in Mexico in 1973 following the introduction of family planning and the abolition of rules prohibiting contraceptives. The laws of 1936 and 1947 favored population growth, but it was due to the improvement of public health (and the resulting drop in mortality rates), agricultural reform, and industrialization that an accelerated demographic expansion occurred. The National Council on Population (CONAPO) was created whose activities include family planning with modern contraceptive technology and maternal-infant health care. In accordance with the goals set in 1977, population growth is sought to be reduced to 1%/year by the year 2000. Public educational programs about reproduction, the family, and the community have been launched. The integration of women into the development of the country under the aegis of the Comision Nacional de las Mujer has not been fully achieved. The processing and analysis of demographic information for longterm policy development has also been limited. The lack of clear guidance from CONAPO has limited the involvement of state and municipal councils in the solution of Mexico's population problems. Future challenges will focus on the legal framework for reconciling public and private interests, and the interaction of population programs and economic and social development. The centralized decision making of population policy has involved more organizations, but still more needs to be done.

  10. Stochastic population dynamics under resource constraints

    Science.gov (United States)

    Gavane, Ajinkya S.; Nigam, Rahul

    2016-06-01

    This paper investigates the population growth of a certain species in which every generation reproduces thrice over a period of predefined time, under certain constraints of resources needed for survival of population. We study the survival period of a species by randomizing the reproduction probabilities within a window at same predefined ages and the resources are being produced by the working force of the population at a variable rate. This randomness in the reproduction rate makes the population growth stochastic in nature and one cannot predict the exact form of evolution. Hence we study the growth by running simulations for such a population and taking an ensemble averaged over 500 to 5000 such simulations as per the need. While the population reproduces in a stochastic manner, we have implemented a constraint on the amount of resources available for the population. This is important to make the simulations more realistic. The rate of resource production then is tuned to find the rate which suits the survival of the species. We also compute the mean life time of the species corresponding to different resource production rate. Study for these outcomes in the parameter space defined by the reproduction probabilities and rate of resource production is carried out.

  11. The population genomics of begomoviruses: global scale population structure and gene flow

    Directory of Open Access Journals (Sweden)

    Prasanna HC

    2010-09-01

    Full Text Available Abstract Background The rapidly growing availability of diverse full genome sequences from across the world is increasing the feasibility of studying the large-scale population processes that underly observable pattern of virus diversity. In particular, characterizing the genetic structure of virus populations could potentially reveal much about how factors such as geographical distributions, host ranges and gene flow between populations combine to produce the discontinuous patterns of genetic diversity that we perceive as distinct virus species. Among the richest and most diverse full genome datasets that are available is that for the dicotyledonous plant infecting genus, Begomovirus, in the Family Geminiviridae. The begomoviruses all share the same whitefly vector, are highly recombinogenic and are distributed throughout tropical and subtropical regions where they seriously threaten the food security of the world's poorest people. Results We focus here on using a model-based population genetic approach to identify the genetically distinct sub-populations within the global begomovirus meta-population. We demonstrate the existence of at least seven major sub-populations that can further be sub-divided into as many as thirty four significantly differentiated and genetically cohesive minor sub-populations. Using the population structure framework revealed in the present study, we further explored the extent of gene flow and recombination between genetic populations. Conclusions Although geographical barriers are apparently the most significant underlying cause of the seven major population sub-divisions, within the framework of these sub-divisions, we explore patterns of gene flow to reveal that both host range differences and genetic barriers to recombination have probably been major contributors to the minor population sub-divisions that we have identified. We believe that the global Begomovirus population structure revealed here could

  12. ILO and its population information activities.

    Science.gov (United States)

    1982-04-01

    The International Labor Organisation (ILO) has authorized population activities since 1968. During the 1970s a population "focal point" was set up for promoting, programming, coordinating and monitoring population activities, and a large scale research program on population and employment was initiated as part of the World Employment Program. Both aspects were incorporated in a Population and Labor Policies Branch in 1975. Population documentation in the ILO is the concern of the Documentation Unit in that Branch, and the Central Library and Documentation Branch of the General Analysis of Labor Problems Department. The Documentation Unit collects materials on population in relation to employment, income and mobility; development planning models, role of women; and population and family welfare education, including printed, visual and audiovisual materials. Available reference tools include subject indexes using terms from the ILO Thesaurus. Monthly accessions lists and periodic bibliographies of relevant ILO publications are produced. The Central Library collects materials on a wide range of related subjects and has been automated since 1965. Its machine readable library file, LABORDOC, is available through Systems Development Corporation. It also produces an abstract journal (International Labor Documentation), a bibliographic list of international organization documents of interest to ILO officials (IGODOC), and a machine readable file describing the 9000 periodicals received or published by the ILO. Publications of the ILO's Bureau of Statistics include Bulletin and Year Book of Labor Statistics and regional volumes of Labor Force Estimates and Projections. The ILO recognizes that much relevant material produced by ILO field offices and other external offices may not reach and be collected at headquarters; the Population Information Network might provide a means of filling this gap.

  13. Divergence in sink contributions to population persistence.

    Science.gov (United States)

    Heinrichs, Julie A; Lawler, Joshua J; Schumaker, Nathan H; Wilsey, Chad B; Bender, Darren J

    2015-12-01

    Population sinks present unique conservation challenges. The loss of individuals in sinks can compromise persistence; but conversely, sinks can improve viability by improving connectivity and facilitating the recolonization of vacant sources. To assess the contribution of sinks to regional population persistence of declining populations, we simulated source-sink dynamics for 3 very different endangered species: Black-capped Vireos (Vireo atricapilla) at Fort Hood, Texas, Ord's kangaroo rats (Dipodomys ordii) in Alberta, and Northern Spotted Owls (Strix occidentalis caurina) in the northwestern United States. We used empirical data from these case studies to parameterize spatially explicit individual-based models. We then used the models to quantify population abundance and persistence with and without long-term sinks. The contributions of sink habitats varied widely. Sinks were detrimental, particularly when they functioned as strong sinks with few emigrants in declining populations (e.g., Alberta's Ord's kangaroo rat) and benign in robust populations (e.g., Black-capped Vireos) when Brown-headed Cowbird (Molothrus ater) parasitism was controlled. Sinks, including ecological traps, were also crucial in delaying declines when there were few sources (e.g., in Black-capped Vireo populations with no Cowbird control). Sink contributions were also nuanced. For example, sinks that supported large, variable populations were subject to greater extinction risk (e.g., Northern Spotted Owls). In each of our case studies, new context-dependent sinks emerged, underscoring the dynamic nature of sources and sinks and the need for frequent re-assessment. Our results imply that management actions based on assumptions that sink habitats are generally harmful or helpful risk undermining conservation efforts for declining populations.

  14. Fish population persistence in hydrologically variable landscapes.

    Science.gov (United States)

    Bond, Nick R; Balcombe, Stephen R; Crook, David A; Marshall, Jonathan C; Menke, Norbert; Lobegeiger, Jaye S

    2015-06-01

    Forecasting population persistence in environments subjected to periodic disturbances represents a general challenge for ecologists. In arid and semiarid regions, climate change and human water use pose significant threats to the future persistence of aquatic biota whose populations typically depend on permanent refuge waterholes for their viability. As such, habitats are increasingly being lost as a result of decreasing runoff and increasing water extraction. We constructed a spatially explicit population model for golden perch Macquaria ambigua (Richardson), a native freshwater fish in the Murray-Darling Basin in eastern Australia. We then used the model to examine the effects of increased aridity, increased drought frequency, and localized human water extraction on population viability. Consistent with current observations, the model predicted golden perch population persistence under the current climate and levels of water use. Modeled increases in local water extraction greatly increased the risk of population decline, while scenarios of increasing aridity and drought frequency were associated with only minor increases in this risk. We conclude that natural variability in abundances and high turnover rates (extinction/recolonization) of local populations dictate the importance of spatial connectivity and periodic cycles of population growth. Our study also demonstrates an effective way to examine population persistence in intermittent and ephemeral river systems by integrating spatial and temporal dynamics of waterhole persistence with demographic processes (survival, recruitment, and dispersal) within a stochastic modeling framework. The approach can be used to help understand the impacts of natural and anthropogenic drivers, including water resource development, on the viability of biota inhabiting highly dynamic environments. PMID:26465032

  15. The sensitivity analysis of population projections

    Directory of Open Access Journals (Sweden)

    Hal Caswell

    2015-10-01

    Full Text Available Background: Population projections using the cohort component method can be written as time-varyingmatrix population models. The matrices are parameterized by schedules of mortality, fertility,immigration, and emigration over the duration of the projection. A variety of dependentvariables are routinely calculated (the population vector, various weighted population sizes, dependency ratios, etc. from such projections. Objective: Our goal is to derive and apply theory to compute the sensitivity and the elasticity (proportional sensitivity of any projection outcome to changes in any of the parameters, where those changes are applied at any time during the projection interval. Methods: We use matrix calculus to derive a set of equations for the sensitivity and elasticity of any vector valued outcome ξ(t at time t to any perturbation of a parameter vector Ɵ(s at anytime s. Results: The results appear in the form of a set of dynamic equations for the derivatives that areintegrated in parallel with the dynamic equations for the projection itself. We show resultsfor single-sex projections and for the more detailed case of projections including age distributions for both sexes. We apply the results to a projection of the population of Spain, from 2012 to 2052, prepared by the Instituto Nacional de Estadística, and determine the sensitivity and elasticity of (1 total population, (2 the school-age population, (3 the population subject to dementia, (4 the total dependency ratio, and (5 the economicsupport ratio. Conclusions: Writing population projections in matrix form makes sensitivity analysis possible. Such analyses are a powerful tool for the exploration of how detailed aspects of the projectionoutput are determined by the mortality, fertility, and migration schedules that underlie theprojection.

  16. Evolution of altruistic punishment in heterogeneous populations.

    Science.gov (United States)

    de Weerd, Harmen; Verbrugge, Rineke

    2011-12-01

    Evolutionary models for altruistic behavior typically make the assumption of homogeneity: each individual has the same costs and benefits associated with cooperating with each other and punishing for selfish behavior. In this paper, we relax this assumption by separating the population into heterogeneous classes, such that individuals from different classes differ in their ability to punish for selfishness. We compare the effects of introducing heterogeneity this way across two population models, that each represents a different type of population: the infinite and well-mixed population describes the way workers of social insects such as ants are organized, while a spatially structured population is more related to the way social norms evolve and are maintained in a social network. We find that heterogeneity in the effectiveness of punishment by itself has little to no effect on whether or not altruistic behavior will stabilize in a population. In contrast, heterogeneity in the cost that individuals pay to punish for selfish behavior allows altruistic behavior to be maintained more easily. Fewer punishers are needed to deter selfish behavior, and the individuals that punish will mostly belong to the class that pays a lower cost to do so. This effect is amplified when individuals that pay a lower cost for punishing inflict a higher punishment. The two population models differ when individuals that pay a low cost for punishing also inflict a lower punishment. In this situation, altruistic behavior becomes harder to maintain in an infinite and well-mixed population. However, this effect does not occur when the population is spatially structured.

  17. Population-environment linkages in international law

    Energy Technology Data Exchange (ETDEWEB)

    Babor, D.D.M.

    1999-03-31

    This article explores population-environment linkages both within developed and developing nations, and considers the consequences of a population growth rate which, as one hectare of arable land is simultaneously lost or destroyed, currently results in eight live births every three seconds. In order to better comprehend the forces governing their perceptions, Part 1 of this article will discuss eight interactive variables which inform decision-making. Part 2 will examine the existence of legal duties under international law to limit or constrain the level of consumption and the right to freely reproduce, particularly as applicable in states considered free of a population problem.

  18. Effects of population outcrossing on rotifer fitness

    Directory of Open Access Journals (Sweden)

    Serra Manuel

    2010-10-01

    Full Text Available Abstract Background Outcrossing between populations can exert either positive or negative effects on offspring fitness. Cyclically parthenogenetic rotifers, like other continental zooplankters, show high genetic differentiation despite their high potential for passive dispersal. Within this context, the effects of outcrossing may be relevant in modulating gene flow between populations through selection for or against interpopulation hybrids. Nevertheless, these effects remain practically unexplored in rotifers. Here, the consequences of outcrossing on the rotifer Brachionus plicatilis were investigated. Cross-mating experiments were performed between a reference population and three alternative populations that differed in their genetic distance with regard to the former. Two offspring generations were obtained: F1 and BC ('backcross'. Fitness of the outcrossed offspring was compared with fitness of the offspring of the reference population for both generations and for three different between-population combinations. Four fitness components were measured throughout the rotifer life cycle: the diapausing egg-hatching proportion, clone viability (for the clones originating from diapausing eggs, initial net growth rate R for each viable clone, and the proportion of male-producing clones. Additionally, both the parental fertilisation proportion and a compound fitness measure, integrating the complete life cycle, were estimated. Results In the F1 generation, hybrid vigour was detected for the diapausing egg-hatching proportion, while R was lower in the outcrossed offspring than in the offspring of the reference population. Despite these contrasting results, hybrid vigour was globally observed for the compound measure of fitness. Moreover, there was evidence that this vigour could increase with the genetic differentiation of the outcrossed populations. In the BC generation, the hybrid vigour detected for the egg-hatching proportion in the F1

  19. Accounting for population variation in targeted proteomics

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, Grant M.; Monroe, Matthew E.; Rodriguez, Larissa M.; Wu, Chaochao; MacLean, Brendan; Smith, Richard D.; MacCoss, Michael; Payne, Samuel H.

    2014-01-03

    Individual proteomes typically differ from the reference human proteome at ~10,000 single amino acid variants. When viewed at the population scale, this individual variation results in a wide variety of protein sequences. In targeted proteomics experiments, such variability would confound accurate protein quantification. To facilitate researchers in identifying target peptides with high variability within the human population we have created the Population Variation plug-in for Skyline, which provides easy access to the polymorphisms stored in dbSNP. Given a set of peptides, the tool reports minor allele frequency for common polymorphisms. We highlight the importance of considering genetic variation by applying the tool to public datasets.

  20. Extinction rate fragility in population dynamics.

    Science.gov (United States)

    Khasin, M; Dykman, M I

    2009-08-01

    Population extinction is of central interest for population dynamics. It may occur from a large rare fluctuation. We find that, in contrast to related large-fluctuation effects like noise-induced interstate switching, quite generally extinction rates in multipopulation systems display fragility, where the height of the effective barrier to be overcome in the fluctuation depends on the system parameters nonanalytically. We show that one of the best-known models of epidemiology, the susceptible-infectious-susceptible model, is fragile to total population fluctuations.

  1. Infant mortality: an insured population perspective.

    Science.gov (United States)

    Zimmerman, Daniel D; Roudebush, Brad

    2012-01-01

    Many insurers offer life coverage to individuals during the first year of life. The policies tend to have small face values, but frequently contain premium waiver or additional purchase options. General population mortality is significantly higher at this age relative to older children and even middle-aged adults. This article presents the mortality experience of an insured cohort in which death occurred under 1 year of age. In summary, the insured population's mortality rate was significantly lower and the leading causes of death were different than the general population.

  2. Patterns of admixture and population structure in native populations of Northwest North America.

    Directory of Open Access Journals (Sweden)

    Paul Verdu

    2014-08-01

    Full Text Available The initial contact of European populations with indigenous populations of the Americas produced diverse admixture processes across North, Central, and South America. Recent studies have examined the genetic structure of indigenous populations of Latin America and the Caribbean and their admixed descendants, reporting on the genomic impact of the history of admixture with colonizing populations of European and African ancestry. However, relatively little genomic research has been conducted on admixture in indigenous North American populations. In this study, we analyze genomic data at 475,109 single-nucleotide polymorphisms sampled in indigenous peoples of the Pacific Northwest in British Columbia and Southeast Alaska, populations with a well-documented history of contact with European and Asian traders, fishermen, and contract laborers. We find that the indigenous populations of the Pacific Northwest have higher gene diversity than Latin American indigenous populations. Among the Pacific Northwest populations, interior groups provide more evidence for East Asian admixture, whereas coastal groups have higher levels of European admixture. In contrast with many Latin American indigenous populations, the variance of admixture is high in each of the Pacific Northwest indigenous populations, as expected for recent and ongoing admixture processes. The results reveal some similarities but notable differences between admixture patterns in the Pacific Northwest and those in Latin America, contributing to a more detailed understanding of the genomic consequences of European colonization events throughout the Americas.

  3. Population Characteristics and Future Population Countermeasures for the Studied Counties in Tibet, China

    Institute of Scientific and Technical Information of China (English)

    LIU Jian; PENG Chuan-zhong; LI Xiang-mei; ZHONG Xiang-hao

    2005-01-01

    Focusing on the 18 counties along "One River and Two Tributaries" region, and based on the data from China 3rd, 4th and 5th population censuses, this article has analyzed the time and spatial changing patterns of the population in this region. The analyses show that since the 3rd population census, total population, average age and total birth rate have all changed considerably: ① Total population has grown fast, with most counties' annual average growth rate of more than 10. ② In terms of the region's average age, in 2000 the age in the 18 counties is younger than 30 years old. ③ Compared with the 3rd population census, labor force by the 5th census is much younger. ④ Countermeasures are proposed to control population by controlling birth rate as the result of the local resident's quality improvement by education.

  4. Population Scalability Analysis of Abstract Population-based Random Search: Spectral Radius

    CERN Document Server

    He, Jun

    2011-01-01

    Population-based Random Search (RS) algorithms, such as Evolutionary Algorithms (EAs), Ant Colony Optimization (ACO), Artificial Immune Systems (AIS) and Particle Swarm Optimization (PSO), have been widely applied to solving discrete optimization problems. A common belief in this area is that the performance of a population-based RS algorithm may improve if increasing its population size. The term of population scalability is used to describe the relationship between the performance of RS algorithms and their population size. Although understanding population scalability is important to design efficient RS algorithms, there exist few theoretical results about population scalability so far. Among those limited results, most of them belong to case studies, e.g. simple RS algorithms for simple problems. Different from them, the paper aims at providing a general study. A large family of RS algorithms, called ARS, has been investigated in the paper. The main contribution of this paper is to introduce a novel appro...

  5. Impact of Population Stratification on Family-Based Association in an Admixed Population

    Directory of Open Access Journals (Sweden)

    T. B. Mersha

    2015-01-01

    Full Text Available Population substructure is a well-known confounder in population-based case-control genetic studies, but its impact in family-based studies is unclear. We performed population substructure analysis using extended families of admixed population to evaluate power and Type I error in an association study framework. Our analysis shows that power was improved by 1.5% after principal components adjustment. Type I error was also reduced by 2.2% after adjusting for family substratification. The presence of population substructure was underscored by discriminant analysis, in which over 92% of individuals were correctly assigned to their actual family using only 100 principal components. This study demonstrates the importance of adjusting for population substructure in family-based studies of admixed populations.

  6. Impact of Population Stratification on Family-Based Association in an Admixed Population.

    Science.gov (United States)

    Mersha, T B; Ding, L; He, H; Alexander, E S; Zhang, X; Kurowski, B G; Pilipenko, V; Kottyan, L; Martin, L J; Fardo, D W

    2015-01-01

    Population substructure is a well-known confounder in population-based case-control genetic studies, but its impact in family-based studies is unclear. We performed population substructure analysis using extended families of admixed population to evaluate power and Type I error in an association study framework. Our analysis shows that power was improved by 1.5% after principal components adjustment. Type I error was also reduced by 2.2% after adjusting for family substratification. The presence of population substructure was underscored by discriminant analysis, in which over 92% of individuals were correctly assigned to their actual family using only 100 principal components. This study demonstrates the importance of adjusting for population substructure in family-based studies of admixed populations. PMID:26064873

  7. Population genetic data on four STR loci in a Hungarian Romany population.

    Science.gov (United States)

    Füredi, S; Kozma, Z; Woller, J; Pádár, Z; Angyal, M; Bajnóczky, I; Nishi, K

    1998-01-01

    A population study of Hungarian Romanies was carried out on the STR loci HumLPL, HumF13B, HumFES and HumF1301. There was little evidence for association of alleles within/between the four STR systems. Allele frequency distributions were significantly different between the Romany and the previously reported Central Hungarian population databases. Population differentiation was estimated by computing F- and phi-statistics as well as frequency estimate differences of individual phenotypes for these two population samples. The results suggest that the population structure may have an effect on the interpretation of forensic DNA evidence in Hungary. Phylogenetic tree reconstruction with six populations from three major ethnic groups revealed a relatively distant genetic relationship of the Baranya Romanies with other Caucasian populations.

  8. Estimation of the effective population size (Ne) and its application in the management of small populations

    DEFF Research Database (Denmark)

    Jimenez Mena, Belen

    2016-01-01

    windows within chromosomes. Heterogeneity in Ne has implications for conservation management as Ne is used to evaluate the threat status of populations. Ne can vary locally along the genome, hence a population can be wrongly classified if heterogeneity in Ne is not taken into account when assessing...... the population against threat status thresholds. When molecular markers are not available, populations can be managed using pedigree information. However, this is challenging to do so for group-living species since individuals and their parentage are difficult to determine. We adapted a pedigree-based method......Effective population size (Ne) is an important concept to understand the evolution of a population. In conservation, Ne is used to assess the threat status of a population, evaluate its genetic viability in the future and set conservation priorities. An accurate estimation of Ne is thus essential...

  9. Plasmodium vivax populations revisited: mitochondrial genomes of temperate strains in Asia suggest ancient population expansion

    Directory of Open Access Journals (Sweden)

    Miao Miao

    2012-02-01

    Full Text Available Abstract Background Plasmodium vivax is the most widely distributed human malaria parasite outside of Africa, and its range extends well into the temperate zones. Previous studies provided evidence for vivax population differentiation, but temperate vivax parasites were not well represented in these analyses. Here we address this deficit by using complete mitochondrial (mt genome sequences to elucidate the broad genetic diversity and population structure of P. vivax from temperate regions in East and Southeast Asia. Results From the complete mtDNA sequences of 99 clinical samples collected in China, Myanmar and Korea, a total of 30 different haplotypes were identified from 26 polymorphic sites. Significant differentiation between different East and Southeast Asian parasite populations was observed except for the comparison between populations from Korea and southern China. Haplotype patterns and structure diversity analysis showed coexistence of two different groups in East Asia, which were genetically related to the Southeast Asian population and Myanmar population, respectively. The demographic history of P. vivax, examined using neutrality tests and mismatch distribution analyses, revealed population expansion events across the entire P. vivax range and the Myanmar population. Bayesian skyline analysis further supported the occurrence of ancient P. vivax population expansion. Conclusions This study provided further resolution of the population structure and evolution of P. vivax, especially in temperate/warm-temperate endemic areas of Asia. The results revealed divergence of the P. vivax populations in temperate regions of China and Korea from other populations. Multiple analyses confirmed ancient population expansion of this parasite. The extensive genetic diversity of the P. vivax populations is consistent with phenotypic plasticity of the parasites, which has implications for malaria control.

  10. Distribution, population structure and ecosystem effects

    Directory of Open Access Journals (Sweden)

    Irena V. Telesh

    2006-06-01

    Full Text Available Spatial distribution, density, biomass, population structure,predation effects, and the influence of abiotic environmentalcharacteristics (salinity, water temperature, transparency, anddepth on a population of the Ponto-Caspian invasive cladoceranCercopagis pengoi (Ostroumov, 1891 were studied in the Gulf of Finlandand the open Baltic Sea (August 1999 and 2004. In our studyin 1999, this species was first recorded in plankton of opensouth-eastern Baltic waters. The age and sexual structure ofthe C. pengoi population were interrelated with population density.The strongest impact of C. pengoi predation on the pelagic communityin the Gulf of Finland was registered at the stations where thepercentage of C. pengoi in the total zooplankton biomass wasthe highest. The calculated impact values of C. pengoi exceededthose registered a decade ago, during the first years after Cercopagishad invaded the eastern Gulf of Finland.

  11. Structured population models in biology and epidemiology

    CERN Document Server

    Ruan, Shigui

    2008-01-01

    This book consists of six chapters written by leading researchers in mathematical biology. These chapters present recent and important developments in the study of structured population models in biology and epidemiology. Topics include population models structured by age, size, and spatial position; size-structured models for metapopulations, macroparasitc diseases, and prion proliferation; models for transmission of microparasites between host populations living on non-coincident spatial domains; spatiotemporal patterns of disease spread; method of aggregation of variables in population dynamics; and biofilm models. It is suitable as a textbook for a mathematical biology course or a summer school at the advanced undergraduate and graduate level. It can also serve as a reference book for researchers looking for either interesting and specific problems to work on or useful techniques and discussions of some particular problems.

  12. Septic tank additive impacts on microbial populations.

    Science.gov (United States)

    Pradhan, S; Hoover, M T; Clark, G H; Gumpertz, M; Wollum, A G; Cobb, C; Strock, J

    2008-01-01

    Environmental health specialists, other onsite wastewater professionals, scientists, and homeowners have questioned the effectiveness of septic tank additives. This paper describes an independent, third-party, field scale, research study of the effects of three liquid bacterial septic tank additives and a control (no additive) on septic tank microbial populations. Microbial populations were measured quarterly in a field study for 12 months in 48 full-size, functioning septic tanks. Bacterial populations in the 48 septic tanks were statistically analyzed with a mixed linear model. Additive effects were assessed for three septic tank maintenance levels (low, intermediate, and high). Dunnett's t-test for tank bacteria (alpha = .05) indicated that none of the treatments were significantly different, overall, from the control at the statistical level tested. In addition, the additives had no significant effects on septic tank bacterial populations at any of the septic tank maintenance levels. Additional controlled, field-based research iswarranted, however, to address additional additives and experimental conditions.

  13. Galactic civilizations: Population dynamics and interstellar diffusion

    Science.gov (United States)

    Newman, W. I.; Sagan, C.

    1978-01-01

    The interstellar diffusion of galactic civilizations is reexamined by potential theory; both numerical and analytical solutions are derived for the nonlinear partial differential equations which specify a range of relevant models, drawn from blast wave physics, soil science, and, especially, population biology. An essential feature of these models is that, for all civilizations, population growth must be limited by the carrying capacity of the environment. Dispersal is fundamentally a diffusion process; a density-dependent diffusivity describes interstellar emigration. Two models are considered: the first describing zero population growth (ZPG), and the second which also includes local growth and saturation of a planetary population, and for which an asymptotic traveling wave solution is found.

  14. Population dynamics of marine birds: Annual report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The characteristic dynamics of Alaskan marine bird populations are being described from studies conducted at 12 OCSEAP-funded and 6nonOCSEAP-funded U. S. Fish and...

  15. Waterfowl Breeding Population and Habitat Survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Waterfowl Breeding Population and Habitat Survey was initiated experimentally in 1947 and became operational in 1955. It is conducted cooperatively by the U.S....

  16. Waterfowl breeding population survey: Southern Manitoba: 1983

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for southern Manitoba during 1983. The primary purpose of the survey is to provide...

  17. Comparative productivity of six bald eagle populations

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Charles L. Braley (1958) reported a drastic decline in a bald eagle (Haliaeetus leucocephalus) population during the late 1950's. He documented a marked reduction...

  18. Western Ontario: Waterfowl breeding population survey: 1998

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for western Ontario during 1998. The primary purpose of the survey is to provide...

  19. Federal census of the population in Switzerland

    CERN Multimedia

    DG Unit

    2011-01-01

    A federal census of the 2010 population has been underway since January 2011. The objective is to provide important insights into the composition of the resident population, households and families in Switzerland and identify trends. The census methods have been modernised so that it covers only information that is not already contained in Federal, Cantonal and municipal registries of persons; the information will be gathered via questionnaires issued to approximately 3% of the population residing in Switzerland. In order to obtain representative information about the local population, the Canton of Geneva has requested that questionnaires be issued to international civil servants and members of their families aged 15 and over who live in the Canton. They will be invited to respond to the questionnaire on a strictly voluntary basis. If they choose not to respond to the questionnaire, they will not be contacted again. The Permanent Swiss Mission to the International Organizations in Geneva wishes in advance t...

  20. The demographic imperative: managing population growth

    NARCIS (Netherlands)

    A.M. Fischer (Andrew Martín)

    2010-01-01

    textabstractWith global population predicted to rise to over nine billion this century, can we find a solution to the problem of ever-increasing strains on resources without resorting to alarmism and xenophobia?