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Sample records for lolium multiflorum populations

  1. Identification of quantitative trait loci for seed trait and floral morphology in a field-grown Lolium perenne x Lolium multiflorum mapping population

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lolium multiflorum Lam. and L. perenne L. differ in the requirements for initiation of flowering, and in other morphological traits. Generally, L. multiflorum spikes are larger than L. perenne spikes, and have more spikelets, more florets per spikelet, larger seeds, and awns. The greater number of s...

  2. Predation of italian ryegrass (Lolium multiflorum) seed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Italian ryegrass (Lolium multiflorum Lam.) can be a productive and high-quality cool-season forage, but is considered a weed in some pastures. Italian ryegrass does not form a persistent seed bank and needs to produce sufficient seed annually for effective re-establishment. Before the re-seeding ...

  3. Differential Response to Glyphosate in Italian Ryegrass (Lolium multiflorum) Populations from Mississippi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two Italian ryegrass populations from Mississippi, Tribbett and Fratesi, were suspected to be tolerant to glyphosate. A third population from Mississippi, Elizabeth, known to be susceptible to glyphosate, was included for comparison. Plants, 10- to 15-cm-tall (3 to 6 leaves, 2 to 3 tillers), were tr...

  4. EPSPS gene amplification in glyphosate-resistant in Italian ryegrass (Lolium perenne ssp. multiflorum) populations from Arkansas, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glyphosate-resistant Italian ryegrass was detected in Arkansas, USA in 2007. In 2014, 45 populations were confirmed resistant in eight counties across the state. The level of resistance and resistance mechanisms in six populations was studied to assess the severity of the problem and identify altern...

  5. EPSPS Gene Amplification in Glyphosate-Resistant Italian Ryegrass (Lolium perenne ssp. multiflorum) Populations from Arkansas (United States).

    PubMed

    Salas, Reiofeli A; Scott, Robert C; Dayan, Franck E; Burgos, Nilda R

    2015-07-01

    Glyphosate-resistant Italian ryegrass was detected in Arkansas (United States) in 2007. In 2014, 45 populations were confirmed resistant in eight counties across the state. The level of resistance and resistance mechanisms in six populations were studied to assess the severity of the problem and identify alternative management approaches. Dose-response bioassays, glyphosate absorption and translocation experiments, herbicide target (EPSPS) gene sequence analysis, and gene amplification assays were conducted. The dose causing 50% growth reduction (GR50) was 7-19 times higher for the resistant population than for the susceptible standard. Uptake and translocation of (14)C-glyphosate were similar in resistant and susceptible plants, and no mutation in the EPSPS gene known to be associated with resistance to glyphosate was detected. Resistant plants contained from 11- to >100-fold more copies of the EPSPS gene than the susceptible plants, whereas the susceptible plants had only one copy of EPSPS. Plants surviving the recommended dose of glyphosate contained at least 10 copies. The EPSPS copy number was positively related to glyphosate resistance level (r = 80). Therefore, resistance to glyphosate in these populations is due to multiplication of the target site. Resistance mechanisms could be location-specific. Suppressing the mechanism for gene amplification may overcome resistance. PMID:25760654

  6. Multiple Herbicide Resistance in Lolium multiflorum and Identification of Conserved Regulatory Elements of Herbicide Resistance Genes.

    PubMed

    Mahmood, Khalid; Mathiassen, Solvejg K; Kristensen, Michael; Kudsk, Per

    2016-01-01

    Herbicide resistance is a ubiquitous challenge to herbicide sustainability and a looming threat to control weeds in crops. Recently four genes were found constituently over-expressed in herbicide resistant individuals of Lolium rigidum, a close relative of Lolium multiflorum. These include two cytochrome P450s, one nitronate monooxygenase and one glycosyl-transferase. Higher expressions of these four herbicide metabolism related (HMR) genes were also observed after herbicides exposure in the gene expression databases, indicating them as reliable markers. In order to get an overview of herbicidal resistance status of L. multiflorum L, 19 field populations were collected. Among these populations, four populations were found to be resistant to acetolactate synthase (ALS) inhibitors while three exhibited resistance to acetyl-CoA carboxylase (ACCase) inhibitors in our initial screening and dose response study. The genotyping showed the presence of mutations Trp-574-Leu and Ile-2041-Asn in ALS and ACCase, respectively, and qPCR experiments revealed the enhanced expression of HMR genes in individuals of certain resistant populations. Moreover, co-expression networks and promoter analyses of HMR genes in O. sativa and A. thaliana resulted in the identification of a cis-regulatory motif and zinc finger transcription factors. The identified transcription factors were highly expressed similar to HMR genes in response to xenobiotics whereas the identified motif is known to play a vital role in coping with environmental stresses and maintaining genome stability. Overall, our findings provide an important step forward toward a better understanding of metabolism-based herbicide resistance that can be utilized to devise novel strategies of weed management. PMID:27547209

  7. Multiple Herbicide Resistance in Lolium multiflorum and Identification of Conserved Regulatory Elements of Herbicide Resistance Genes

    PubMed Central

    Mahmood, Khalid; Mathiassen, Solvejg K.; Kristensen, Michael; Kudsk, Per

    2016-01-01

    Herbicide resistance is a ubiquitous challenge to herbicide sustainability and a looming threat to control weeds in crops. Recently four genes were found constituently over-expressed in herbicide resistant individuals of Lolium rigidum, a close relative of Lolium multiflorum. These include two cytochrome P450s, one nitronate monooxygenase and one glycosyl-transferase. Higher expressions of these four herbicide metabolism related (HMR) genes were also observed after herbicides exposure in the gene expression databases, indicating them as reliable markers. In order to get an overview of herbicidal resistance status of L. multiflorum L, 19 field populations were collected. Among these populations, four populations were found to be resistant to acetolactate synthase (ALS) inhibitors while three exhibited resistance to acetyl-CoA carboxylase (ACCase) inhibitors in our initial screening and dose response study. The genotyping showed the presence of mutations Trp-574-Leu and Ile-2041-Asn in ALS and ACCase, respectively, and qPCR experiments revealed the enhanced expression of HMR genes in individuals of certain resistant populations. Moreover, co-expression networks and promoter analyses of HMR genes in O. sativa and A. thaliana resulted in the identification of a cis-regulatory motif and zinc finger transcription factors. The identified transcription factors were highly expressed similar to HMR genes in response to xenobiotics whereas the identified motif is known to play a vital role in coping with environmental stresses and maintaining genome stability. Overall, our findings provide an important step forward toward a better understanding of metabolism-based herbicide resistance that can be utilized to devise novel strategies of weed management. PMID:27547209

  8. Effects of accelerated aging on italian ryegrass (Lolium multiflorum) seed germination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Italian ryegrass (Lolium multiflorum) is a productive, high quality cool-season forage that is overseeded in warm-season pastures for winter and early spring grazing. However, in some pastures and croplands it can be a serious weed. Italian ryegrass does not form an extensive seed bank and the see...

  9. Identification of Anguina funesta from annual ryegrass (Lolium multiflorum) seed lots in Oregon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2010, seed galls containing Anguina sp. were isolated from 14 annual ryegrass (Lolium multiflorum) seed lots submitted for phytosanitary testing. To identify the species present, the ITS1 region of the ribosomal DNA of the nematodes from the seed lots was analyzed using a PCR-RFLP method (11). ...

  10. Utilization of flow cytometry for festulolium breeding (Lolium multiflorum (2x) × Festuca arundinacea (6x))

    PubMed Central

    Akiyama, Yukio; Ueyama, Yasufumi; Hamada, Seiya; Kubota, Akito; Kato, Daisuke; Yamada-Akiyama, Hitomi; Takahara, Yoshinori; Fujimori, Masahiro

    2016-01-01

    Festulolium is a hybrid between Festuca and Lolium species that has valuable agronomic traits from both grass species. The purpose of our breeding program is to produce hexaploid festulolium that introduces tolerance to summer depression into Italian ryegrass (Lolium multiflorum) by crossing it with tall fescue (Festuca arundinacea). However, we found the DNA ploidy of hexaploids was not stable and was reduced in successive generations. We aimed to find out how to obtain stable high-ploidy festulolium. F1 hybrids of L. multiflorum and F. arundinacea were produced. The F3 generation was produced from putative hexaploid F2 individuals by open pollination. The F4 to F6 generations were obtained by polycrossing. The DNA ploidy levels of F2 to F6 individuals were estimated by flow cytometry. Cytological characteristics of the F5 and F6 individuals were investigated by FISH and GISH. The DNA ploidy level of hexaploid festulolium was reduced and stabilized at almost the same level as a tetraploid. Seed fertility was inversely correlated with an increase in ploidy level. GISH revealed no preferential Lolium transmission. FISH with a telomere probe revealed that counting the exact number of chromosomes in festulolium was difficult. DNA ploidy level was strongly correlated with the number of chromosomes. PMID:27162495

  11. Utilization of flow cytometry for festulolium breeding (Lolium multiflorum (2x) × Festuca arundinacea (6x)).

    PubMed

    Akiyama, Yukio; Ueyama, Yasufumi; Hamada, Seiya; Kubota, Akito; Kato, Daisuke; Yamada-Akiyama, Hitomi; Takahara, Yoshinori; Fujimori, Masahiro

    2016-03-01

    Festulolium is a hybrid between Festuca and Lolium species that has valuable agronomic traits from both grass species. The purpose of our breeding program is to produce hexaploid festulolium that introduces tolerance to summer depression into Italian ryegrass (Lolium multiflorum) by crossing it with tall fescue (Festuca arundinacea). However, we found the DNA ploidy of hexaploids was not stable and was reduced in successive generations. We aimed to find out how to obtain stable high-ploidy festulolium. F1 hybrids of L. multiflorum and F. arundinacea were produced. The F3 generation was produced from putative hexaploid F2 individuals by open pollination. The F4 to F6 generations were obtained by polycrossing. The DNA ploidy levels of F2 to F6 individuals were estimated by flow cytometry. Cytological characteristics of the F5 and F6 individuals were investigated by FISH and GISH. The DNA ploidy level of hexaploid festulolium was reduced and stabilized at almost the same level as a tetraploid. Seed fertility was inversely correlated with an increase in ploidy level. GISH revealed no preferential Lolium transmission. FISH with a telomere probe revealed that counting the exact number of chromosomes in festulolium was difficult. DNA ploidy level was strongly correlated with the number of chromosomes. PMID:27162495

  12. Italian ryegrass (Lolium multiflorum) and corn (Zea mays)competition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Italian ryegrass is an annual/biennial grass that is typically used as a pasture crop or a cover crop along roadsides, rights-of-way, and industrial areas. Glyphosate-resistant (GR) Italian ryegrass populations have been documented around the world, mostly in orchard and vineyard situations. The fir...

  13. Enhancement of nitrogen and phosphorus removal from eutrophic water by economic plant annual ryegrass (Lolium multiflorum) with ion implantation.

    PubMed

    Li, Miao; Sheng, Guo-ping; Wu, Yue-jin; Yu, Zeng-liang; Bañuelos, Gary S; Yu, Han-qing

    2014-01-01

    Severe eutrophication of surface water has been a major problem of increasing environmental concern worldwide. In the present study, economic plant annual ryegrass (Lolium multiflorum) was grown in floating mats as an economic plant-based treatment system to evaluate its potential after ion implantation for removing nutrients in simulated eutrophic water. The specific weight growth rate of L. multiflorum with ion implantation was significantly greater than that of the control, and the peroxidase, nitrate reductase, and acid phosphatase activities of the irradiated L. multiflorum were found to be greater than those plants without ion implantation. Higher total nitrogen (TN) and total phosphorus (TP) removal efficiencies were obtained for the L. multiflorum irradiated with 25 keV 5.2 × 10(16) N(+) ions/cm(2) and 30 keV 4.16 × 10(16) N(+) ions/cm(2), respectively (p < 0.05). Furthermore, the nitrogen and phosphorus contents in the plant biomass with ion implantation were also greater than those in the control and were positively correlated with TN and TP supplied. L. multiflorum itself was directly responsible for 39-49 and 47-58 % of the overall N and P removal in the experiment, respectively. The research results suggested that ion implantation could become a promising approach for increasing phytoremediation efficiency of nutrients from eutrophic water by L. multiflorum. PMID:24809498

  14. Effect of D2O on growth properties and chemical structure of annual ryegrass (Lolium multiflorum)

    SciTech Connect

    Evans, Barbara R; Bali, Garima; Reeves, David T; O'Neill, Hugh Michael; Sun, Qining; Shah, Riddhi S; Ragauskas, Arthur

    2014-01-01

    In present paper, we report the production and detailed structural analysis of deuterium-enriched rye grass (Lolium multiflorum) for neutron scattering experiments. An efficient method to produce deuterated biomass was developed by designing hydroponic perfusion chambers. In preliminary studies, the partial deuterated rye samples were grown in increasing levels of D2O to study the seed germination and the level of deuterium incorporation as a function of D2O concentration. Solution NMR method indicated 36.9 % deuterium incorporation in 50 % D2O grown annual rye samples and further significant increase in the deuterium incorporation level was observed by germinating the rye seedlings in H2O and growing in 50 % D2O inside the perfusion chambers. Moreover, in an effort to compare the substrate characteristics related to enzymatic hydrolysis on deuterated and protiated version of biomass, annual rye grown in 50 % D2O was selected for detailed biomass characterization studies. The compositional analyses, degree of polymerization and cellulose crystallinity were compared with its protiated control. The cellulose molecular weight indicated slight variation with deuteration; however, hemicellulose molecular weights and cellulose crystallinity remain unaffected with the deuteration. Besides the minor differences in biomass components, the development of deuterated biomass for neutron scattering application is essential to understand the complex biomass conversion processes.

  15. Influence of tea saponin on enhancing accessibility of pyrene and cadmium phytoremediated with Lolium multiflorum in co-contaminated soils.

    PubMed

    Wang, Qian; Liu, Xiaoyan; Zhang, Xinying; Hou, Yunyun; Hu, Xiaoxin; Liang, Xia; Chen, Xueping

    2016-03-01

    Tea saponin (TS), a kind of biodegradable surfactant, was chosen to improve the accessible solubilization of pyrene and cadmium (Cd) in co-contaminated soils cultivated Lolium multiflorum. TS obviously improved the accessibility of pyrene and Cd for L. multiflorum to accelerate the process of accumulation and elimination of the pollutants. The chemical forms of Cd was transformed from Fe-Mn oxides and associated to carbonates fractions into exchangeable fractions by adding TS in single Cd and pyrene-Cd contaminated soils. Moreover, the chemical forms of pyrene were transformed from associated fraction into bioaccessible fraction by adding TS in pyrene and pyrene-Cd contaminated soils. In pyrene-Cd contaminated soil, the exchangeable fraction of Cd was hindered in the existence of pyrene, and bioaccessible fraction of pyrene was promoted by the cadmium. Besides, in the process of the pyrene degradation and Cd accumulation, the effect could be improved by the elongation of roots with adding TS, and the microorganism activity was stimulated by TS to accelerate the removal of pollutions. Therefore, Planting L. multiflorum combined with adding TS would be an effective method on the phytoremediation of organics and heavy metals co-contaminated soils. PMID:26581690

  16. Transcriptional Profiles of Drought-Related Genes in Modulating Metabolic Processes and Antioxidant Defenses in Lolium multiflorum

    PubMed Central

    Pan, Ling; Zhang, Xinquan; Wang, Jianping; Ma, Xiao; Zhou, Meiliang; Huang, LinKai; Nie, Gang; Wang, Pengxi; Yang, Zhongfu; Li, Ji

    2016-01-01

    Drought is a major environmental stress that limits growth and development of cool-season annual grasses. Drought transcriptional profiles of resistant and susceptible lines were studied to understand the molecular mechanisms of drought tolerance in annual ryegrass (Lolium multiflorum L.). A total of 4718 genes exhibited significantly differential expression in two L. multiflorum lines. Additionally, up-regulated genes associated with drought response in the resistant lines were compared with susceptible lines. Gene ontology enrichment and pathway analyses revealed that genes partially encoding drought-responsive proteins as key regulators were significantly involved in carbon metabolism, lipid metabolism, and signal transduction. Comparable gene expression was used to identify the genes that contribute to the high drought tolerance in resistant lines of annual ryegrass. Moreover, we proposed the hypothesis that short-term drought have a beneficial effect on oxidation stress, which may be ascribed to a direct effect on the drought tolerance of annual ryegrass. Evidence suggests that some of the genes encoding antioxidants (HPTs, GGT, AP, 6-PGD, and G6PDH) function as antioxidant in lipid metabolism and signal transduction pathways, which have indispensable and promoting roles in drought resistance. This study provides the first transcriptome data on the induction of drought-related gene expression in annual ryegrass, especially via modulation of metabolic homeostasis, signal transduction, and antioxidant defenses to improve drought tolerance response to short-term drought stress. PMID:27200005

  17. Effects of olive mill wastewater physico-chemical treatments on polyphenol abatement and Italian ryegrass (Lolium multiflorum Lam.) germinability.

    PubMed

    Barbera, A C; Maucieri, C; Ioppolo, A; Milani, M; Cavallaro, V

    2014-04-01

    Direct spreading on agricultural lands may represent an environmentally friendly disposal method and a possible use of water and nutrients from olive mill wastewaters (OMWs). However, the agronomic use of OMWs is limited, among others by polyphenols, which exert phytotoxic effects. Activated charcoal (AC) has been recognized as a very effective agent for polyphenol abatement, as it enables an irreversible process of phenol adsorption. Addition of calcium hydroxide (Ca(OH)2) has also been described as a cheap and effective method in polyphenols abatement. However, the effects of Ca(OH)2 addition to OMW on seed germination are unclear. In this paper, the effects of AC and/or Ca(OH)2 on OMW polyphenols abatement, and Lolium multiflorum seed germination have been investigated. The highest polyphenols removal, approximately 95%, was observed when 80 g L(-1) of AC was added to OMWs (the maximum dose in this investigation). The addition of Ca(OH)2 not only improved the effectiveness of the AC treatment but also resulted in a significant rise in Lolium seed germination at the highest AC doses (60 and 80 g L(-1)). Considering the high salinity (7300 μS cm(-1)) of these wastewaters, low quantities of Ca(OH)2 may also exert a protective effect on soil structure counteracting the sodium-induced dispersion through the binding action of calcium cation on clays and organic matter. PMID:24289894

  18. Chemical Composition, In vivo Digestibility and Metabolizable Energy Values of Caramba (Lolium multiflorum cv. caramba) Fresh, Silage and Hay

    PubMed Central

    Özelçam, H.; Kırkpınar, F.; Tan, K.

    2015-01-01

    The experiment was conducted to determine nutritive values of caramba (Lolium multiflorum cv. caramba) fresh, silage and hay by in vivo and in vitro methods. There was a statistically significant difference (p<0.01) in crude protein content value between fresh caramba (12.83%) and silage (8.91%) and hay (6.35%). According to results of experiment, the crude fiber, neutral detergent fiber, acid detergent fiber (ADF), acid detergent lignin contents of the three forms of caramba varied between 30.22% to 35.06%, 57.41% to 63.70%, 35.32% to 43.29%, and 5.55% to 8.86% respectively. There were no significant differences between the three forms of caramba in digestibility of nutrients and in vivo metabolizable energy (ME) values (p>0.05). However, the highest MECN (ME was estimated using crude nutrients) and MEADF values were found in fresh caramba (p<0.01). As a result, it could be said that, there were no differences between the three forms of caramba in nutrient composition, digestibility and ME value, besides drying and ensiling did not affect digestibility of hay. Consequently, caramba either as fresh, silage or hay is a good alternative source of forage for ruminants. PMID:26323399

  19. Chemical Composition, In vivo Digestibility and Metabolizable Energy Values of Caramba (Lolium multiflorum cv. caramba) Fresh, Silage and Hay.

    PubMed

    Özelçam, H; Kırkpınar, F; Tan, K

    2015-10-01

    The experiment was conducted to determine nutritive values of caramba (Lolium multiflorum cv. caramba) fresh, silage and hay by in vivo and in vitro methods. There was a statistically significant difference (p<0.01) in crude protein content value between fresh caramba (12.83%) and silage (8.91%) and hay (6.35%). According to results of experiment, the crude fiber, neutral detergent fiber, acid detergent fiber (ADF), acid detergent lignin contents of the three forms of caramba varied between 30.22% to 35.06%, 57.41% to 63.70%, 35.32% to 43.29%, and 5.55% to 8.86% respectively. There were no significant differences between the three forms of caramba in digestibility of nutrients and in vivo metabolizable energy (ME) values (p>0.05). However, the highest MECN (ME was estimated using crude nutrients) and MEADF values were found in fresh caramba (p<0.01). As a result, it could be said that, there were no differences between the three forms of caramba in nutrient composition, digestibility and ME value, besides drying and ensiling did not affect digestibility of hay. Consequently, caramba either as fresh, silage or hay is a good alternative source of forage for ruminants. PMID:26323399

  20. Factors Influencing beta-Glucan Synthesis by Particulate Enzymes from Suspension-Cultured Lolium multiflorum Endosperm Cells.

    PubMed

    Henry, R J; Stone, B A

    1982-03-01

    Particulate enzymes from suspension-cultured ryegrass (Lolium multiflorum Lam.) endosperm cells incorporated glucosyl residues from UDP-glucose and GDP-glucose into beta-glucans. Three types of beta-glucans were produced from UDP-glucose: 1,3-beta-glucan; 1,4-beta-glucan; and mixed-linkage 1,3;1,4-beta-glucan. As in other systems, relatively more 1,4-beta-glucan was produced from a low (10 micromolar) UDP-glucose concentration, and relatively more 1,3-beta-glucan was produced from a high (1 millimolar) UDP-glucose concentration. However, in ryegrass, 1,3;1,4-beta-glucan represented a major proportion of the products at both low and high UDP-glucose concentrations. The arrangement of linkages in the 1,3;1,4-beta-glucan was different at the two concentrations; at the low UDP-glucose concentration, more sequences of three consecutive 1,4-linkages were produced.The effects of pH, temperature, and metal ion concentrations on incorporation were dependent on the UDP-glucose concentration. At the low UDP-glucose concentration, incorporation into all three types of beta-glucan increased with increasing pH. At the high UDP-glucose concentration, 1,3-beta-glucan was the major product at pH 7 and below; 1,4-beta-glucan synthesis was optimal at pH 8; and synthesis of 1,3;1,4-beta-glucan was greatest above pH 8.With 10 micromolar GDP-glucose as substrate, 1,4-beta-glucan, but no 1,3;1,4-beta-glucan, was produced. Incorporation from either UDP-glucose or GDP-glucose was not influenced by the presence of the other. PMID:16662263

  1. Fragile sites of 45S rDNA of Lolium multiflorum are not hotspots for chromosomal breakages induced by X-ray.

    PubMed

    Rocha, Laiane Corsini; Mittelmann, Andrea; Houben, Andreas; Techio, Vânia Helena

    2016-07-01

    Sites of 45S rDNA of Lolium are regions denominated fragile sites (FSs), constituting regions slightly stained with DAPI due to increased DNA unpacking in metaphasic chromosomes. Considered to be fragile regions in the genome, the FSs might be more responsive to induced breaks and result in chromosomal fragments and rearrangements, unless repairing mechanisms such as recombination or de novo telomere formation play a role at the break site of the DNA. Thus, this study aimed at investigating if SFs from Lolium are hotspots for the occurrence of breakages induced by X-ray and if they are regions favorable to synthesize new telomeres, using Hordeum vulgare as a comparative model. Lolium multiflorum and H. vulgare seedlings were irradiated with 20 and 50 Gy X-ray and evaluated one day following the irradiation and at 7-days intervals for a 28-days period, using FISH technique with 45S rDNA and Arabidopsis-type telomere probes in order to investigate the presence of chromosomal breakages and new telomere formation. H. vulgare did not survive after a few days of irradiation due to the increased rate of abnormalities. L. multiflorum also exhibited chromosomal abnormalities following the exposure, yet over the 28-days trial it had a decrease in the chromosomal damage rate and formation of de novo telomere has not been detected along this time. Despite being considered to be fragile regions in the genome, the 45S rDNA sites of Lolium are not hotspots to chromosomal breakages after the induction of breakages. PMID:27174104

  2. Glyphosate-tolerance mechanism in Italian ryegrass (Lolium multiflorum) from Mississippi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A 3-fold glyphosate tolerance was identified in two Italian ryegrass populations, T1 and T2, from Mississippi. Laboratory experiments were conducted to characterize the mechanism of glyphosate tolerance in these populations. The T1 population absorbed less 14C-glyphosate (43% of applied) compared to...

  3. Transpiration flow controls Zn transport in Brassica napus and Lolium multiflorum under toxic levels as evidenced from isotopic fractionation

    NASA Astrophysics Data System (ADS)

    Couder, Eléonore; Mattielli, Nadine; Drouet, Thomas; Smolders, Erik; Delvaux, Bruno; Iserentant, Anne; Meeus, Coralie; Maerschalk, Claude; Opfergelt, Sophie; Houben, David

    2015-11-01

    Stable zinc (Zn) isotope fractionation between soil and plant has been used to suggest the mechanisms affecting Zn uptake under toxic conditions. Here, changes in Zn isotope composition in soil, soil solution, root and shoot were studied for ryegrass (Lolium multiflorum L.) and rape (Brassica napus L.) grown on three distinct metal-contaminated soils collected near Zn smelters (total Zn 0.7-7.5%, pH 4.8-7.3). The Zn concentrations in plants reflected a toxic Zn supply. The Zn isotopic fingerprint of total soil Zn varied from -0.05‰ to +0.26 ± 0.02‰ (δ66Zn values relative to the JMC 3-0749L standard) among soils, but the soil solution Zn was depleted in 66Zn, with a constant Zn isotope fractionation of about -0.1‰ δ66Zn unit compared to the bulk soil. Roots were enriched with 66Zn relative to soil solution (δ66Znroot - δ66Znsoil solution = Δ66Znroot-soil solution = +0.05 to +0.2 ‰) and shoots were strongly depleted in 66Zn relative to roots (Δ66Znshoot-root = -0.40 to -0.04 ‰). The overall δ66Zn values in shoots reflected that of the bulk soil, but were lowered by 0.1-0.3 ‰ units as compared to the latter. The isotope fractionation between root and shoot exhibited a markedly strong negative correlation (R2 = 0.83) with transpiration per unit of plant weight. Thus, the enrichment with light Zn isotopes in shoot progressed with increasing water flux per unit plant biomass dry weight, showing a passive mode of Zn transport by transpiration. Besides, the light isotope enrichment in shoots compared to roots was larger for rape than for rye grass, which may be related to the higher Zn retention in rape roots. This in turn may be related to the higher cation exchange capacity of rape roots. Our finding can be of use to trace the biogeochemical cycles of Zn and evidence the tolerance strategies developed by plants in Zn-excess conditions.

  4. In vitro and in vivo enhancement of adipogenesis by Italian ryegrass (Lolium multiflorum) in 3T3-L1 cells and mice.

    PubMed

    Valan Arasu, Mariadhas; Ilavenil, Soundharrajan; Kim, Da Hye; Gun Roh, Sang; Lee, Jeong-Chae; Choi, Ki Choon

    2014-01-01

    Adipogenesis is very much important in improving the quality of meat in animals. The aim of the present study was to investigate the in vitro and in vivo adipogenesis regulation properties of Lolium multiflorum on 3T3-L1 pre-adipocytes and mice. Chemical composition of petroleum ether extract of L. multiflorum (PET-LM) confirmed the presence of fatty acids, such as α-linolenic acid, docosahexaenoic acid, oleic acid, docosatetraenoic acid, and caprylic acid, as the major compounds. PET-LM treatment increased viability, lipid accumulation, lipolysis, cell cycle progression, and DNA synthesis in the cells. PET-LM treatment also augmented peroxysome proliferator activated receptor (PPAR)-γ2, CCAAT/enhancer binding protein-α, adiponectin, adipocyte binding protein, glucose transporter-4, fatty acid synthase, and sterol regulatory element binding protein-1 expression at mRNA and protein levels in differentiated adipocytes. In addition, mice administered with 200 mg/kg body weight PET-LM for 8 weeks showed greater body weight than control mice. These findings suggest that PET-LM facilitates adipogenesis by stimulating PPARγ-mediated signaling cascades in adipocytes which could be useful for quality meat development in animals. PMID:24454838

  5. In Vitro and In Vivo Enhancement of Adipogenesis by Italian Ryegrass (Lolium multiflorum) in 3T3-L1 Cells and Mice

    PubMed Central

    Kim, Da Hye; Gun Roh, Sang; Lee, Jeong-Chae; Choi, Ki Choon

    2014-01-01

    Adipogenesis is very much important in improving the quality of meat in animals. The aim of the present study was to investigate the in vitro and in vivo adipogenesis regulation properties of Lolium multiflorum on 3T3-L1 pre-adipocytes and mice. Chemical composition of petroleum ether extract of L. multiflorum (PET-LM) confirmed the presence of fatty acids, such as α-linolenic acid, docosahexaenoic acid, oleic acid, docosatetraenoic acid, and caprylic acid, as the major compounds. PET-LM treatment increased viability, lipid accumulation, lipolysis, cell cycle progression, and DNA synthesis in the cells. PET-LM treatment also augmented peroxysome proliferator activated receptor (PPAR)-γ2, CCAAT/enhancer binding protein-α, adiponectin, adipocyte binding protein, glucose transporter-4, fatty acid synthase, and sterol regulatory element binding protein-1 expression at mRNA and protein levels in differentiated adipocytes. In addition, mice administered with 200 mg/kg body weight PET-LM for 8 weeks showed greater body weight than control mice. These findings suggest that PET-LM facilitates adipogenesis by stimulating PPARγ-mediated signaling cascades in adipocytes which could be useful for quality meat development in animals. PMID:24454838

  6. Effects of chlorsulfuron on diclofop-methyl toxicity to Italian ryegrass (Lolium multiflorum) and Italian ryegrass interference in wheat (triticum aestivum)

    SciTech Connect

    Liebl, R.A.

    1985-01-01

    Chlorsulfuron )2-chloro-N-(((4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino)carbonyl)benzenesulfonamide) and diclofop-methyl )methyl 2-(4-(2,4-dichlorophenoxy)phenoxy)propanoate) are herbicides used for the selective control of broadleaf and grassy weeds, respectively, in wheat (Triticum aestivum L.). The addition of chlorsulfuron (14.8 g ai/ha) to 0.90 kg ai/ha diclofop-methyl and applied postemergence reduced Italian ryegrass (Lolium multiflorum L.) control 27% and increased fresh weights over diclofop-methyl alone. Chlorsulfuron and diclofop-methyl were approximately 200 and 35%, respectively, more active on Italian ryegrass when applied pre-emergence compared to postemergence applications and responses of the combinations were additive. Although little movement of /sup 14/C-label occurred in either species, significantly more /sup 14/C-label translocated from the treated zone of Italian ryegrass. In metabolism studies, wheat was able to detoxify diclofop-methyl more rapidly than Italian ryegrass. In field interference studies, wheat grain yields were reduced an average of 4.2% for every 10 Italian ryegrass plants/m/sup 2/ because of decreased crop tillering. Italian ryegrass had net nitrate and potassium influx rates approximately 2-times greater than those for wheat when plants were growing in nutrient solution in the greenhouse.

  7. Analysis of Antioxidant Enzyme Activity and Antioxidant Genes Expression During Germination of Two Different Genotypes of Lolium multiflorum Under Salt Tolerance.

    PubMed

    Wang, Xia; Ma, Xiao; Xinquan-Zhang; Linkai-Huang; Li, Zhou; Nie, Wenzhi-Xu Gang

    2016-01-01

    Annual ryegrass (Lolium multiflorum) is widely used as a cool-season forage grass for its luxuriant growth, palatable and high digestible. To investigate the salt tolerance mechanism in annual ryegrass under salt stress, salt-tolerant genotype 'R102-3' and salt-sensitive genotype 'Tetragold' were subject to 300mmol/L NaCl in a controlled growth chamber for 12 days. The results showed high concentrations of NaCl decreased relative water content (RWC), and increased the electrolyte leakage (EL) in both genotypes. However the 'Tetragold' had a greater increased extent of malondialdehyde (MDA) and EL than in 'R102-3', in contrast, the activities of Superoxide (SOD), Peroxidase (POD), Catalase (CAT) and Ascorbate peroxidase (APX) were higher in salt resistant compared to sensitive ones. For ensure the accurate of qRT-PCR, we used RefFinder to choose the most stably reference genes eEF1A(s) and GAPDH to normalize the antioxidant genes expression data. The results indicated that higher expression of Fe-SOD, Mn-SOD, Chl-Cu/Zn SOD, Cyt-Cu/Zn SOD, POD and CAT in 'R102-3' when compared with 'Tetragold', which may play an important role in defensed damage of Reactive oxygen species (ROS) under salt stress. Thus, the salt-tolerant genotype could effectively resist oxidative damage induced by salt tress relative to salt-sensitive genotype. PMID:26972970

  8. Water Deficit Affects Primary Metabolism Differently in Two Lolium multiflorum/Festuca arundinacea Introgression Forms with a Distinct Capacity for Photosynthesis and Membrane Regeneration

    PubMed Central

    Perlikowski, Dawid; Czyżniejewski, Mariusz; Marczak, Łukasz; Augustyniak, Adam; Kosmala, Arkadiusz

    2016-01-01

    Understanding how plants respond to drought at different levels of cell metabolism is an important aspect of research on the mechanisms involved in stress tolerance. Furthermore, a dissection of drought tolerance into its crucial components by the use of plant introgression forms facilitates to analyze this trait more deeply. The important components of plant drought tolerance are the capacity for photosynthesis under drought conditions, and the ability of cellular membrane regeneration after stress cessation. Two closely related introgression forms of Lolium multiflorum/Festuca arundinacea, differing in the level of photosynthetic capacity during stress, and in the ability to regenerate their cellular membranes after stress cessation, were used as forage grass models in a primary metabolome profiling and in an evaluation of chloroplast 1,6-bisphosphate aldolase accumulation level and activity, during 11 days of water deficit, followed by 10 days of rehydration. It was revealed here that the introgression form, characterized by the ability to regenerate membranes after rehydration, contained higher amounts of proline, melibiose, galactaric acid, myo-inositol and myo-inositol-1-phosphate involved in osmoprotection and stress signaling under drought. Moreover, during the rehydration period, this form also maintained elevated accumulation levels of most the primary metabolites, analyzed here. The other introgression form, characterized by the higher capacity for photosynthesis, revealed a higher accumulation level and activity of chloroplast aldolase under drought conditions, and higher accumulation levels of most photosynthetic products during control and drought periods. The potential impact of the observed metabolic alterations on cellular membrane recovery after stress cessation, and on a photosynthetic capacity under drought conditions in grasses, are discussed. PMID:27504113

  9. Water Deficit Affects Primary Metabolism Differently in Two Lolium multiflorum/Festuca arundinacea Introgression Forms with a Distinct Capacity for Photosynthesis and Membrane Regeneration.

    PubMed

    Perlikowski, Dawid; Czyżniejewski, Mariusz; Marczak, Łukasz; Augustyniak, Adam; Kosmala, Arkadiusz

    2016-01-01

    Understanding how plants respond to drought at different levels of cell metabolism is an important aspect of research on the mechanisms involved in stress tolerance. Furthermore, a dissection of drought tolerance into its crucial components by the use of plant introgression forms facilitates to analyze this trait more deeply. The important components of plant drought tolerance are the capacity for photosynthesis under drought conditions, and the ability of cellular membrane regeneration after stress cessation. Two closely related introgression forms of Lolium multiflorum/Festuca arundinacea, differing in the level of photosynthetic capacity during stress, and in the ability to regenerate their cellular membranes after stress cessation, were used as forage grass models in a primary metabolome profiling and in an evaluation of chloroplast 1,6-bisphosphate aldolase accumulation level and activity, during 11 days of water deficit, followed by 10 days of rehydration. It was revealed here that the introgression form, characterized by the ability to regenerate membranes after rehydration, contained higher amounts of proline, melibiose, galactaric acid, myo-inositol and myo-inositol-1-phosphate involved in osmoprotection and stress signaling under drought. Moreover, during the rehydration period, this form also maintained elevated accumulation levels of most the primary metabolites, analyzed here. The other introgression form, characterized by the higher capacity for photosynthesis, revealed a higher accumulation level and activity of chloroplast aldolase under drought conditions, and higher accumulation levels of most photosynthetic products during control and drought periods. The potential impact of the observed metabolic alterations on cellular membrane recovery after stress cessation, and on a photosynthetic capacity under drought conditions in grasses, are discussed. PMID:27504113

  10. ESPS gene amplification endows resistance to glyphosate in Italian ryegrass (Lolium perene ssp multiflorum) from Arkansas, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Resistance to glyphosate in weed species is a major challenge for the sustainability of glyphosate use in crop and non-crop systems, and especially in glyphosate-resistant crops. A glyphosate-resistant Italian ryegrass population has been identified in Arkansas. This research was conducted to elucid...

  11. Implementation of Genomic Prediction in Lolium perenne (L.) Breeding Populations

    PubMed Central

    Grinberg, Nastasiya F.; Lovatt, Alan; Hegarty, Matt; Lovatt, Andi; Skøt, Kirsten P.; Kelly, Rhys; Blackmore, Tina; Thorogood, Danny; King, Ross D.; Armstead, Ian; Powell, Wayne; Skøt, Leif

    2016-01-01

    Perennial ryegrass (Lolium perenne L.) is one of the most widely grown forage grasses in temperate agriculture. In order to maintain and increase its usage as forage in livestock agriculture, there is a continued need for improvement in biomass yield, quality, disease resistance, and seed yield. Genetic gain for traits such as biomass yield has been relatively modest. This has been attributed to its long breeding cycle, and the necessity to use population based breeding methods. Thanks to recent advances in genotyping techniques there is increasing interest in genomic selection from which genomically estimated breeding values are derived. In this paper we compare the classical RRBLUP model with state-of-the-art machine learning techniques that should yield themselves easily to use in GS and demonstrate their application to predicting quantitative traits in a breeding population of L. perenne. Prediction accuracies varied from 0 to 0.59 depending on trait, prediction model and composition of the training population. The BLUP model produced the highest prediction accuracies for most traits and training populations. Forage quality traits had the highest accuracies compared to yield related traits. There appeared to be no clear pattern to the effect of the training population composition on the prediction accuracies. The heritability of the forage quality traits was generally higher than for the yield related traits, and could partly explain the difference in accuracy. Some population structure was evident in the breeding populations, and probably contributed to the varying effects of training population on the predictions. The average linkage disequilibrium between adjacent markers ranged from 0.121 to 0.215. Higher marker density and larger training population closely related with the test population are likely to improve the prediction accuracy. PMID:26904088

  12. Self-Reseeding Potential and Herbage Production of Italian Ryegrass (Lolium Multiflorum Lam.) Affected by Date and Intensity of Initial Harvest

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Annually-sown cool-season small grain cereals can provide a valuable source of cool-season feeding for livestock in the southern Great Plains of the USA, but for many farmers limited access to field equipment for cultivation and planting is an obstacle to their use. Italian ryegrass (Lolium multiflo...

  13. QTL ANALYSIS OF FIBER COMPONENTS AND CRUDE PROTEIN IN AN ANNUAL X PERENNIAL RYEGRASS POPULATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Annual (Lolium multiflorum Lam.) and perennial (Lolium perenne L.) ryegrass are two common forage species in temperate regions. Improving the digestibility of forage by decreasing fiber content is a major goal in forage crop breeding programs. An annual X perennial ryegrass population was used to ma...

  14. Utilizing genetically diverse Festuca arundinaceae recoveries from a Lolium multiflorum x Festuca arundinaceae population to evaluate endophyte interaction and performance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Development of cool-season perennial grass forages exhibiting adaptation and persistence to the environmental extremes of the southern plains region of the USA would provide an important contribution toward sustaining the regions grazing livestock industry. Festuca arundinaceae, a sustainable cool-...

  15. Molecular Characterization and Taxonomy of Lolium Latent Virus, a Novel Member of the Family Flexiviridae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lolium latent virus (LoLV) was recently detected in the United States for the first time (Maroon-Lango et al., 2006, Plant Disease 90:528) in ryegrass hybrids (Lolium perenne x multiflorum). The genome of one U.S. isolate, LoLV-US1, has now been fully sequenced. The positive strand genomic RNA is 76...

  16. New report of Lolium multiflorum and Rumex crispus as weed hosts of epiphytic populations of Psuedomonas sp., causal agent of yellow bud in onion in Geogia, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yellow bud, an emerging bacterial disease of onion (Allium cepa L.), has been spreading throughout the Vidalia onion-growing region in Georgia since 2007. Symptoms of yellow bud include intense chlorosis in emerging leaves and severe blight in the older leaves leading to stand loss and reduced bulb ...

  17. QTL for resistance in Lolium perenne to a mixed population of Puccinia graminis subsp. graminicola: use of RAD (restriction site associated DNA) markers to rapidly populate a new linkage map

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A mapping population was created to detect quantitative trait loci (QTL) for resistance to stem rust caused by Puccinia graminis subsp. graminicola in Lolium perenne. Susceptible and resistant plants were crossed to produce a pseudo-testcross population. Markers were produced by the Restriction-sit...

  18. Pathotype-specific QTL for stem rust resistance in Lolium perenne

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A genetic map populated with RAD and SSR markers was created from F1 progeny of a stem rust-susceptible and stem rust-resistant parent of perennial ryegrass (Lolium perenne). The map has markers in common with several other Lolium spp. maps including EST-SSR anchor markers from a consensus map. A ...

  19. Windrow burning eliminates Italian Ryegrass (Lolium perenne ssp. multiflorum) seed viability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Burning of crop residues that have been concentrated behind the harvest combine (windrowed) is one of several harvest weed seed control strategies that have been developed and evaluated in Australia to address the widespread evolution of multiple herbicide resistance in annual weeds. Herbicide-resis...

  20. Does leaf manipulation affect leaf appearance in italian ryegrass (Lolium multiflorum Lam.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mechanical stimuli such as rubbing, shaking, or flexing plants can alter their growth rates and morphologies. Plant response to mechanical stress can result in delayed plant growth, reduced leaf size, shorten and thicken stems, and reduced yields. Repeated measurements, such as leaf counting or me...

  1. Effects of elevated CO2 levels on root morphological traits and Cd uptakes of two Lolium species under Cd stress*

    PubMed Central

    Jia, Yan; Tang, Shi-rong; Ju, Xue-hai; Shu, Li-na; Tu, Shu-xing; Feng, Ren-wei; Giusti, Lorenzino

    2011-01-01

    This study was conducted to investigate the combined effects of elevated CO2 levels and cadmium (Cd) on the root morphological traits and Cd accumulation in Lolium multiflorum Lam. and Lolium perenne L. exposed to two CO2 levels (360 and 1000 μl/L) and three Cd levels (0, 4, and 16 mg/L) under hydroponic conditions. The results show that elevated levels of CO2 increased shoot biomass more, compared to root biomass, but decreased Cd concentrations in all plant tissues. Cd exposure caused toxicity to both Lolium species, as shown by the restrictions of the root morphological parameters including root length, surface area, volume, and tip numbers. These parameters were significantly higher under elevated levels of CO2 than under ambient CO2, especially for the number of fine roots. The increases in magnitudes of those parameters triggered by elevated levels of CO2 under Cd stress were more than those under non-Cd stress, suggesting an ameliorated Cd stress under elevated levels of CO2. The total Cd uptake per pot, calculated on the basis of biomass, was significantly greater under elevated levels of CO2 than under ambient CO2. Ameliorated Cd toxicity, decreased Cd concentration, and altered root morphological traits in both Lolium species under elevated levels of CO2 may have implications in food safety and phytoremediation. PMID:21462388

  2. Comparison of ribosomal DNA sites in Lolium species by fluorescence in situ hybridization.

    PubMed

    Thomas, H M; Harper, J A; Meredith, M R; Morgan, W G; Thomas, I D; Timms, E; King, I P

    1996-11-01

    The position of the 18S-5.8S-26S and 5S rRNA genes have been physically mapped on the chromosomes of seven Lolium taxa. 18S-5.8S-26S sites were seen on two pairs of chromosomes in the inbreeding taxa. In the outbreeding taxa six sites were found in the L. multiflorum, seven in L. perenne and nine in L. rigidum var. rigidum. Two 5S sites were found in each of the taxa. In the inbreeders, the 5S sites were found adjacent to the 18S-5.8S-26S sites on chromosome 2. In L. multifiorum and L.perenne the 5S sites were on the short arm of chromosome 3. However, in L. rigidum var. rigidum the 5S rDNA site was found in either of the two positions. PMID:8939359

  3. Germplasm preservation in vitro of Polygonum multiflorum Thunb

    PubMed Central

    Huang, He-Ping; Wang, Jian; Huang, Lu-Qi; Gao, Shan-Lin; Huang, Peng; Wang, Dian-Lei

    2014-01-01

    Background: The root of Polygonum multiflorum Thunb. is a common traditional Chinese medicine. In recent years, the wild resources of P. multiflorum have been seriously broken, and the cultivated varieties have been degrading. The germplasm resources of P. multiflorum need protection and preservation. So far, no in vitro germplasm preservation of P. multiflorum has been reported. Objective: To explore a method for the in vitro germplasm preservation of P. multiflorum. Materials and Methods: A large number of buds from seed explants were induced by tissue culture. The single buds were used as experimental materials to study the effects of plant growth regulator, temperature, and osmotic pressure on the preservation time, growth recovery, and genetic stability. Results: When the buds were inoculated onto Murashige and Skoog (MS) basal media containing 4% w/v sucrose, 2% w/v mannitol, and 1% w/v sorbitol, supplemented with paclobutrazol (PP333) 1.0 mg/l, abscisic acid (ABA) 5.0 mg/l, and daminozide (B9) 30.0 mg/l in an illuminated chamber under a 16 h photoperiod of 1500 lx light intensity at 15°C for 10 months, the survival rate was over 70% with good growth recovery and genetic stability. Conclusion: The results of this study can be used for medium-term in vitro germplasm preservation of P. multiflorum, and meeting actual needs of research and production. PMID:24914285

  4. Mapping and comparative analysis of QTL for crown rust resistance in an Italian x perennial ryegrass population

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crown rust (Puccinia coronata f.sp. lolli) is a serious fungal foliar disease of perennial ryegrass (Lolium perenne L.) and Italian ryegrass (L. multiflorum L.) which are important forage and turf species. A number of quantitative trait loci (QTL) for crown rust resistance were previously identifie...

  5. Allelopathic effect of Bromus spp. and Lolium spp. shoot extracts on some crops.

    PubMed

    Lehoczky, E; Nelima, M Okumu; Szabó, R; Szalai, A; Nagy, P

    2011-01-01

    Allelopathy is an untapped resource for weed control in crops that could give good possibilities for environmentally sound, integrated crop production. Allelopathy is defined as the direct or indirect harmful or beneficial effects of one plant on another through the production of chemical compounds, called allelochemicals, which escape into the environment. Allelochemicals can be produced by weeds and affect crops, and the reverse is also true. Allelopathic interactions include weed-weed, weed-crop, and crop-crop. Allelopathy offers potential for selective biological weed control for instance weed-suppressing crops and the use of plant residues in cropping systems, allelopathic rotational crops, or companion plants with allelopathic potential. Bromus species occur in many habitats in temperate regions of the world, including America, Eurasia, Australia, and Africa. The genus Lolium is one of the most important forage grasses. The weed species usually grow in the same production zones as wheat and are considered weeds since they parasitize wheat fields. Some of the weed species in these two genus have been reported to have allelopathic effect. One of the methods that has been successful in studying allelopathic activity are bioassays. Laboratory experiments were conducted to determine allelopathic effect of watery shoot extracts of four weed species of the Poaceae family, namely Bromus rigidus, Bromus diandrus, Lolium multiflorum and Lolium temulentum on germination and growth of winter wheat (Triticum aestivum L.), spring barley (Hordeum vulgare L.), corn (Zea mays L), perennial ryegrass (Lolium perenne L.), bean (Phaseolus sp.) and sunflower (Helianthus annuus L.) and on each other. The experiment was carried out during the period March 2010 to October 2010. Twenty five seeds were put into one Petri-dish on filter paper, adding 15ml of extract to each in four repeats. The germination took place in a Binder-type thermostat in the dark. The timing of germination was

  6. Feeding strategies for small-scale dairy systems based on perennial (Lolium perenne) or annual (Lolium multiflorum) ryegrass in the central highlands of Mexico.

    PubMed

    Heredia-Nava, D; Espinoza-Ortega, A; González-Esquivel, C E; Arriaga-Jordán, C M

    2007-04-01

    Small-scale dairying is an option for campesinos in Mexico. The costs of feeding are high and strategies based on quality forages are a priority. The performance, agronomic variables and feeding costs were evaluated for dairy cows continuously grazing perennial ryegrass-white clover for 9 h/day (PRG) or fed cut herbage from annual ryegrass for 8 weeks followed by 9 h/day for 6 weeks on a tethered rotational grazing pattern (ARG). All cows received 3 kg/day of an 18% crude protein (CP) concentrate. A 14-week split-plot on-farm experiment was designed with 10 cows from two participating farmers, and 1.5 ha per strategy. Milk yield was recorded weekly and milk composition, live weight and body condition score were recorded every 14 days. Net herbage accumulation was greater for ARG (8222 kg organic matter (OM)/ha) than for PRG (5915 kg OM/ha) (p<0.05), with higher CP in PRG (p<0.05). Milk yield was 19 kg/cow per day for PRG and 15.9 kg/ cow per day for ARG (p>0.05). Over 14 weeks, PRG produced 1422 kg more milk. There were no differences for live weight or condition score (p>0.05), but linear regression shows a live weight gain of 0.200 kg/cow per day for PRG. Protein and fat content showed no differences (p>0.05), but milk fat content in PRG was below standard. ARG had 60% higher costs, and margins were 38% higher in PRG. ARG has a place in rain-fed fields. The results provide viable options for improving these systems that may be suitable in their socio-economic context and their social and personal objectives. PMID:17691542

  7. Linkage Disequilibrium Among Two Lolium Perenne CBF Genes and Association With Freezing Susceptibility

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perennial ryegrass(Lolium perenne) is one of the most abundantly utilized forage and turfgrass species; however, its lack of tolerance to freezing temperatures relative to other forage/turf grasses limits its use. A pseudo-testcross genetic mapping population was previously developed for perennial ...

  8. Virus induced gene silencing in Lolium temulentum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lolium temulentum L. is valuable as a model species for studying abiotic stress in closely related forage and turf grasses, many of which are polyploid outcrossing species. As with most monocot species, Agrobacterium-mediated transformation of L. temulentum is still challenging, time consuming and n...

  9. Vacuolar glyphosate-sequestration correlates with glyphosate resistance in ryegrass (Lolium spp.) from Australia, South America, and Europe: a 31P NMR investigation.

    PubMed

    Ge, Xia; d'Avignon, D André; Ackerman, Joseph J H; Collavo, Alberto; Sattin, Maurizio; Ostrander, Elizabeth L; Hall, Erin L; Sammons, R Douglas; Preston, Christopher

    2012-02-01

    Lolium spp., ryegrass, variants from Australia, Brazil, Chile, and Italy showing differing levels of glyphosate resistance were examined by (31)P NMR. Extents of glyphosate (i) resistance (LD(50)), (ii) inhibition of 5-enopyruvyl-shikimate-3-phosphate synthase (EPSPS) activity (IC(50)), and (iii) translocation were quantified for glyphosate-resistant (GR) and glyphosate-sensitive (GS) Lolium multiflorum Lam. variants from Chile and Brazil. For comparison, LD(50) and IC(50) data for Lolium rigidum Gaudin variants from Italy were also analyzed. All variants showed similar cellular uptake of glyphosate by (31)P NMR. All GR variants showed glyphosate sequestration within the cell vacuole, whereas there was minimal or no vacuole sequestration in the GS variants. The extent of vacuole sequestration correlated qualitatively with the level of resistance. Previous (31)P NMR studies of horseweed ( Conyza canadensis (L.) Cronquist) revealed that glyphosate sequestration imparted glyphosate resistance. Data presented herein suggest that glyphosate vacuolar sequestration is strongly contributing, if not the major contributing, resistance mechanism in ryegrass as well. PMID:22224711

  10. Seed size effects on early seedling growth and response to applied nitrogen in annual ryegrass (Lolium multiflorum L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Use of individual plants as experimental units may be necessary when resources are limited, but inter-plant variation risks obscuring differences among treatments. Experiments were undertaken to measure the effects of seed size on seedling size and response to applied nitrogen of annual ryegrass (Lo...

  11. Enhanced remediation of chlorpyrifos by ryegrass (Lolium multiflorum) and a chlorpyrifos degrading bacterial endophyte Mezorhizobium sp. HN3.

    PubMed

    Jabeen, Hina; Iqbal, Samina; Ahmad, Fiaz; Afzal, Muhammad; Firdous, Sadiqa

    2016-01-01

    For effective remediation of contaminants, plant-endophyte partnership is a promising field to be explored. Generally endophytic bacteria assist their host plant by withstanding the stress induced by the contaminants. The objective of this study was to explore the suitability of plant-bacterial partnership for chlorpyrifos (CP) remediation using ryegrass and a CP degrading endophyte, Mesorhizobium sp. HN3 which belongs to plant growth promoting rhizobia. The inoculated yfp-tagged Mesorhizobium sp. HN3 efficiently colonized in the rhizosphere, enhanced plant growth and degradation of CP and its metabolite 3,5,6 trichloro-2-pyridinol (TCP). Significantly lower CP residues were observed in the roots and shoots of plants vegetated in inoculated soil which might be attributed to the efficient root colonization of HN3yfp. These results suggest the involvement of Mesorhizobium sp. HN3yfp in CP degradation inside the roots and rhizosphere of plants and further emphasize on the effectiveness of endophytic bacteria in stimulating the remediation of pesticide contaminants. This is the first report which demonstrates the efficacy of bacterial endophyte for degradation of CP residues taken up by the plant and enhanced remediation of chlorpyrifos contaminated soil. PMID:26248164

  12. Hair Growth Promotion Activity and Its Mechanism of Polygonum multiflorum

    PubMed Central

    Li, Yunfei; Han, Mingnuan; Lin, Pei; He, Yanran; Yu, Jie; Zhao, Ronghua

    2015-01-01

    Polygonum multiflorum Radix (PMR) has long history in hair growth promotion and hair coloring in clinical applications. However, several crucial problems in its clinic usage and mechanisms are still unsolved or lack scientific evidences. In this research, C57BL/6J mice were used to investigate hair growth promotion activity and possible mechanism of PMR and Polygonum multiflorum Radix Preparata (PMRP). Hair growth promotion activities were investigated by hair length, hair covered skin ratio, the number of follicles, and hair color. Regulation effects of several cytokines involved in the hair growth procedure were tested, such as fibroblast growth factor (FGF-7), Sonic Hedgehog (SHH), β-catenin, insulin-like growth factor-1 (IGF-1), and hepatocyte growth factor (HGF). Oral PMR groups had higher hair covered skin ratio (100 ± 0.00%) than oral PMRP groups (48%~88%). However, topical usage of PMRP had about 90% hair covered skin ratio. Both oral administration of PMR and topically given PMRP showed hair growth promotion activities. PMR was considered to be more suitable for oral administration, while PMRP showed greater effects in external use. The hair growth promotion effect of oral PMR was most probably mediated by the expression of FGF-7, while topical PMRP promoted hair growth by the stimulation of SHH expression. PMID:26294926

  13. Dynamic accumulation analysis on bioactive constituents of Polygonum multiflorum in different collection periods.

    PubMed

    Luo, Yi-yuan; Liu, Juan-xiu; Liu, Xun-hong; Lan, Cai-wu; Hou, Ya; Ma, Yang; Wang, Sheng-nan; Cai, Bao-chang

    2015-07-01

    To study the dynamic change law of bioactive constituents from Polygonum multiflorum, and to explore the optimal harvest period of P. multiflorum. Determination of stilhene glucoside, anthraquinones and catechin from P. multiflorum in different harvest times by MEKC-DAD, and principal component analysis (PCA) was used to comprehensive evaluation for bioactive constituents. There are obvious differences among the contents of active ingredients in various collecting periods samples, the content of stilbene glucoside was the highest in November, the total content of combined anthraquinone was the highest in November and December, the content of catechin was the highest in September. The comprehensive evaluation index obtained with principal component analysis showed that the sample collected in November is significantly higher than those with other samples. The optimal harvest period of P. multiflorum is November. PMID:26697679

  14. CYP1A2 polymorphism in Chinese patients with acute liver injury induced by Polygonum multiflorum.

    PubMed

    Ma, K F; Zhang, X G; Jia, H Y

    2014-01-01

    The objective of this study was to evaluate the genotype and allelic frequencies of CYP1A2 in Chinese patients with acute liver injury induced by Polygonum multiflorum. We examined the clinical mechanism of acute liver injury induced by P. multiflorum. According to the diagnostic criteria for drug-induced liver injury (DILI), 43 cases of P. multiflorum-induced liver injury admitted to the First Affiliated Hospital, Zhejiang University were identified between January 2008 and December 2012. An additional 43 control subjects were also chosen. Several alleles, including 1C, 1F, 2, 7, 9, and 11 of CYP1A2 were amplified from genomic DNA and sequenced. We used the chi-square test to determine whether CYP1A2 allele polymorphisms are associated with acute liver injury induced by P. multiflorum. The frequency of the CYP1A2 1C allele was 46.5% in P. multiflorum-induced DILI patients, which was significantly different from the frequency of 27.9% observed in healthy subjects. The frequency of the CYP1A2 1F allele was 63.9% in P. multiflorum-induced DILI patients, compared to 57.0% in healthy controls; the difference was not significant. The allelic frequencies of CYP1A2 2, CYP1A2 7, CYP1A2 9, and CYP1A2 11 were too low to be detected. The frequency of the CYP1A2 1C mutation in Chinese patients with P. multiflorum-induced acute liver injury differed from that in healthy Chinese people, indicating that CYP1A2 1C is probably related to metabolism of P. multiflorum, which is followed by acute liver injury. PMID:25117321

  15. Fructan synthesis, accumulation and polymer traits. II. Fructan pools in populations of perennial ryegrass (Lolium perenne L.) with variation for water-soluble carbohydrate and candidate genes were not correlated with biosynthetic activity and demonstrated constraints to polymer chain extension

    PubMed Central

    Gallagher, Joe A.; Cairns, Andrew J.; Thomas, David; Timms-Taravella, Emma; Skøt, Kirsten; Charlton, Adam; Williams, Peter; Turner, Lesley B.

    2015-01-01

    Differences have been shown between ryegrass and fescue within the Festulolium subline introgression family for fructan synthesis, metabolism, and polymer-size traits. It is well-established that there is considerable variation for water-soluble carbohydrate and fructan content within perennial ryegrass. However there is much still to be discovered about the fructan polymer pool in this species, especially in regard to its composition and regulation. It is postulated that similar considerable variation for polymer traits may exist, providing useful polymers for biorefining applications. Seasonal effects on fructan content together with fructan synthesis and polymer-size traits have been examined in diverse perennial ryegrass material comprising contrasting plants from a perennial ryegrass F2 mapping family and from populations produced by three rounds of phenotypic selection. Relationships with copy number variation in candidate genes have been investigated. There was little evidence of any variation in fructan metabolism across this diverse germplasm under these conditions that resulted in substantial differences in the complement of fructan polymers present in leaf tissue at high water-soluble carbohydrate concentrations. The importance of fructan synthesis during fructan accumulation was unclear as fructan content and polymer characteristics in intact plants during the growing season did not reflect the capacity for de novo synthesis. However, the retention of fructan in environmental conditions favoring high sink/low source demand may be an important component of the high sugar trait and the roles of breakdown and turnover are discussed. PMID:26528321

  16. Landscape Effects of a Non-Native Grass Facilitate Source Populations of a Native Generalist Bug, Stenotus rubrovittatus, in a Heterogeneous Agricultural Landscape

    PubMed Central

    Yoshioka, A.; Takada, M. B.; Washitani, I.

    2014-01-01

    Non-native plant species can provide native generalist insects, including pests, with novel food and habitats. It is hypothesized that local and landscape-level abundances of non-native plants can affect the population size of generalist insects, although generalists are assumed to be less sensitive to habitat connectivity than specialists. In a heterogeneous landscape in Japan, the relationship between the density of a native pest of rice (Stenotus rubrovittatus (Matsumura) (Heteroptera: Miridae)) and the abundance of Italian ryegrass (Lolium multiflorum Lam. (Poales: Poaceae)), a non-native meadow grass known to facilitate S. rubrovittatus, was analyzed. Statistical analyses of data on bug density, vegetation, and the spatial distribution of fallow fields and meadows dominated by Italian ryegrass, obtained by field surveys, demonstrated that local and landscape-level abundances of Italian ryegrass (the unmowed meadow areas within a few hundred meters of a sampling plot) positively affected bug density before its immigration into rice fields. Our findings suggest that a generalist herbivorous insect that prefers non-native plants responds to spatial availability and connectivity of plant species patches at the metapopulation level. Fragmentation by selective mowing that decreases the total area of source populations and increases the isolation among them would be an effective and environmentally-friendly pest management method. PMID:25205015

  17. Mechanistic Studies on the Use of Polygonum multiflorum for the Treatment of Hair Graying.

    PubMed

    Han, Ming-Nuan; Lu, Jian-Mei; Zhang, Guang-Yuan; Yu, Jie; Zhao, Rong-Hua

    2015-01-01

    Polygonum multiflorum is a traditional Chinese medicine with a long history in hair growth promotion and hair blackening. The purpose of the study was to examine the effect and the mechanism of Polygonum multiflorum in hair blackening. C57BL/6 mice hair fade was induced with H2O2 and used in this research. Hair pigmentogenesis promotion activities of Polygonum Multiflorum Radix (PMR, raw crude drug), Polygonum Multiflorum Radix Preparata (PMRP, processed crude drug), and their major chemical constituent TSG were investigated. The regulation effects of several cytokines and enzymes such as POMC, α-MSH, MC1R, ASIP, MITF, TYR, TRP-1, and TRP-2 were investigated. PMR group gave out the most outstanding black hair among all groups with the highest contents of total melanin, α-MSH, MC1R, and TYR. Promotion of hair pigmentogenesis was slightly decreased after processing in the PMRP group. TSG as the major constituent of PMR showed weaker hair color regulation effects than both PMR and PMRP. PMR, but not PMRP, should be used to blacken hair. The α-MSH, MC1R, and TYR were the major targets in the medicinal use of PMR in hair graying. Chemical constituents other than TSG may contribute to the hair color regulation activity of PMR. PMID:26640791

  18. Mechanistic Studies on the Use of Polygonum multiflorum for the Treatment of Hair Graying

    PubMed Central

    Han, Ming-Nuan; Lu, Jian-Mei; Zhang, Guang-Yuan; Yu, Jie; Zhao, Rong-Hua

    2015-01-01

    Polygonum multiflorum is a traditional Chinese medicine with a long history in hair growth promotion and hair blackening. The purpose of the study was to examine the effect and the mechanism of Polygonum multiflorum in hair blackening. C57BL/6 mice hair fade was induced with H2O2 and used in this research. Hair pigmentogenesis promotion activities of Polygonum Multiflorum Radix (PMR, raw crude drug), Polygonum Multiflorum Radix Preparata (PMRP, processed crude drug), and their major chemical constituent TSG were investigated. The regulation effects of several cytokines and enzymes such as POMC, α-MSH, MC1R, ASIP, MITF, TYR, TRP-1, and TRP-2 were investigated. PMR group gave out the most outstanding black hair among all groups with the highest contents of total melanin, α-MSH, MC1R, and TYR. Promotion of hair pigmentogenesis was slightly decreased after processing in the PMRP group. TSG as the major constituent of PMR showed weaker hair color regulation effects than both PMR and PMRP. PMR, but not PMRP, should be used to blacken hair. The α-MSH, MC1R, and TYR were the major targets in the medicinal use of PMR in hair graying. Chemical constituents other than TSG may contribute to the hair color regulation activity of PMR. PMID:26640791

  19. In vivo transmission of 'candidatus Phytoplasma ulmi' by Amplicephalus curtulus (Hemiptera: Cicadellidae) and its effect on ryegrass (Lolium multiflorum cv. tama).

    PubMed

    Arismendi, N L; Riegel, R; Carrillo, R

    2014-02-01

    In Chile, phytoplasmas have been reported in sugar beet, grapevine, peony, and Chilean shrubs. 'Candidatus Phytoplasma ulmi' have been detected in plants of Ugni molinae Turczanínow (Myrtaceae) and the leafhopper Amplicephalus curtulus Linnavuori & DeLong. We evaluated the possibility of phytoplasma transmission from native plants to grasses by A. curtulus and the possible effect on the plant hosts. Newly emerged adults were placed in cages with phytoplasma-infected U. molinae for 72 h (acquisition access period). These plants were then replaced by healthy ryegrasses for 20 d (latent period). They were again replaced for other healthy ryegrasses and were place in cages for 14, 7, and 1 d (inoculation access period [IAP]). After IAP, these plants were moved into different insect-free cages for 30 d, after which polymerase chain reaction (PCR) analyses were carried out. Phytoplasma-free insects on ryegrasses were considered as control treatments. Furthermore, plant height and leaf area were recorded for all treatments. After PCR, 46, 60, and 13% of the plants exposed to infected A. curtulus by 14, 7, and 1 d of IAP, respectively, were infected with 'Ca. Phytoplasma ulmi'. Similarly, plants exposed to an IAP of 14, 7, and 1 d with phytoplasma-infected leafhoppers showed a reduction in plant height of 19, 39, and 28% and leaf area of 302, 169, and 55%, respectively, in comparison to those exposed to phytoplasma-free leafhoppers. We showed that A. curtulus has the ability to transmit phytoplasma from U. molinae to ryegrasses, affecting ryegrass plant height and leaf area PMID:24665688

  20. Bioaccumulation of platinum group elements and characterization of their species in Lolium multiflorum by size-exclusion chromatography coupled with ICP-MS.

    PubMed

    Lesniewska, Barbara A; Messerschmidt, Jürgen; Jakubowski, Norbert; Hulanicki, Adam

    2004-04-25

    The bioaccumulation of Pt, Pd and Rh by grass grown hydroponically with nutrient solutions containing these ions at elevated (38.7 mg l(-1) Pt, 21.7 mg l(-1) Pd and 7.1 mg l(-1) Rh) and medium (3.6 mg l(-1) Pt, 4.4 mg l(-1) Pd and 0.5 mg l(-1) Rh) concentrations was studied by using inductively coupled plasma sector field mass spectrometry (ICP-SFMS). The highest bioaccumulation factors were obtained for Pd and Rh in roots and for Pt in leaves. The obtained results showed that most of the studied metals were accumulated in roots, and only a small fraction was really metabolised and transported to leaves. The multi-element capability of ICP-SFMS has been exploited to study the metabolism of platinum group elements (PGEs) in cultivated plants. The species of studied metals were extracted from roots and leaves and separated into two mass fractions by ultra-filtration. The low molecular mass (<10 kDa) fractions of the root and the leaf extracts were investigated by size-exclusion chromatography (SEC) coupled on-line to ICP-SFMS. The presence of Ca, Cu, S and C in the same fractions as Pt, Pd and Rh may indicate the interaction of PGEs with phytochelatins and carbohydrates. PMID:15081741

  1. Herbicidal activity of Brassicaceae seed meal on wild oat (Avena fatua), Italian ryegrass (Lolium multiflorum Lam.), redroot pigweed (Amaranthus retroflexus L.) and prickly lettuce (Lactuca serriola)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is an on-going need for the development of sustainable methods of weed control in crop production systems. Studies were conducted to evaluate the efficacy of different Brassicaceae seed meals and application rates on the emergence of several weed species including wild oat, Italian rye grass, ...

  2. Pathotype-specific QTL for stem rust resistance in Lolium perenne.

    PubMed

    Pfender, W F; Slabaugh, M E

    2013-05-01

    A genetic map populated with RAD and SSR markers was created from F1 progeny of a stem rust-susceptible and stem rust-resistant parent of perennial ryegrass (Lolium perenne). The map supplements a previous map of this population by having markers in common with several other Lolium spp. maps including EST-SSR anchor markers from a consensus map published by other researchers. A QTL analysis was conducted with disease severity and infection type data obtained by controlled inoculation of the population with each of two previously characterized pathotypes of Puccinia graminis subsp. graminicola that differ in virulence to different host plant genotypes in the F1 population. Each pathotype activated a specific QTL on one linkage group (LG): qLpPg1 on LG7 for pathotype 101, or qLpPg2 on LG1 for pathotype 106. Both pathotypes also activated a third QTL in common, qLpPg3 on LG6. Anchor markers, present on a consensus map, were located in proximity to each of the three QTL. These QTL had been detected also in previous experiments in which a genetically heterogeneous inoculum of the stem rust pathogen activated all three QTL together. The results of this and a previous study are consistent with the involvement of the pathotype-specific QTL in pathogen recognition and the pathotype-nonspecific QTL in a generalized resistance response. By aligning the markers common to other published reports, it appears that two and possibly all three of the stem rust QTL reported here are in the same general genomic regions containing some of the L. perenne QTL reported to be activated in response to the crown rust pathogen (P. coronata). PMID:23361523

  3. Review of clinical studies of Polygonum multiflorum Thunb. and its isolated bioactive compounds.

    PubMed

    Bounda, Guy-Armel; Feng, Y U

    2015-01-01

    Polygonum multiflorum Thunb. (PMT), officially listed in the Chinese Pharmacopoeia, is one of the most popular perennial Chinese traditional medicines known as He shou wu in China and East Asia, and as Fo-ti in North America. Mounting pharmacological studies have stressed out its key benefice for the treatment of various diseases and medical conditions such as liver injury, cancer, diabetes, alopecia, atherosclerosis, and neurodegenerative diseases as well. International databases such as PubMed/Medline, Science citation Index and Google Scholar were searched for clinical studies recently published on P. multiflorum. Various clinical studies published articles were retrieved, providing information relevant to pharmacokinetics-pharmacodynamics analysis, sleep disorders, dyslipidemia treatment, and neurodegenerative diseases. This review is an effort to update the clinical picture of investigations ever carried on PMT and/or its isolated bio-compounds and to enlighten its therapeutic assessment. PMID:26130933

  4. Review of clinical studies of Polygonum multiflorum Thunb. and its isolated bioactive compounds

    PubMed Central

    Bounda, Guy-Armel; Feng, YU

    2015-01-01

    Polygonum multiflorum Thunb. (PMT), officially listed in the Chinese Pharmacopoeia, is one of the most popular perennial Chinese traditional medicines known as He shou wu in China and East Asia, and as Fo-ti in North America. Mounting pharmacological studies have stressed out its key benefice for the treatment of various diseases and medical conditions such as liver injury, cancer, diabetes, alopecia, atherosclerosis, and neurodegenerative diseases as well. International databases such as PubMed/Medline, Science citation Index and Google Scholar were searched for clinical studies recently published on P. multiflorum. Various clinical studies published articles were retrieved, providing information relevant to pharmacokinetics-pharmacodynamics analysis, sleep disorders, dyslipidemia treatment, and neurodegenerative diseases. This review is an effort to update the clinical picture of investigations ever carried on PMT and/or its isolated bio-compounds and to enlighten its therapeutic assessment. PMID:26130933

  5. Polygonumnolides C1-C4; minor dianthrone glycosides from the roots of Polygonum multiflorum Thunb.

    PubMed

    Yang, Jian-Bo; Li, Li; Dai, Zhong; Wu, Yu; Geng, Xing-Chao; Li, Bo; Ma, Shuang-Cheng; Wang, Ai-Guo; Su, Ya-Lun

    2016-09-01

    Four new dianthrone glycosides, named polygonumnolides C1-C4 (1-4), were isolated from the dried roots of Polygonum multiflorum Thunb, together with two known emodin dianthrones (5-6). Their hepatotoxicities were evaluated against L-02 cell lines. Compounds 1-4 showed weak hepatotoxicity against L-02 cell lines with IC50 values of 313.05, 205.20, 294.20, and 207.35 μM, respectively. PMID:27139982

  6. Transcriptome changes in Polygonum multiflorum Thunb. roots induced by methyl jasmonate.

    PubMed

    Liu, Hong-chang; Wu, Wei; Hou, Kai; Chen, Jun-wen; Zhao, Zhi

    2015-12-01

    Transcriptome profiling has been widely used to analyze transcriptomic variation in plants subjected to abiotic or biotic stresses. Although gene expression changes induced by methyl jasmonate (MeJA) have been profiled in several plant species, no information is available on the MeJA-triggered transcriptome response of Polygonum multiflorum Thunb., a species with highly valuable medicinal properties. In this study, we used transcriptome profiling to investigate transcriptome changes in roots of P. multiflorum seedlings subjected to a 0.25 mmol/L-MeJA root-irrigation treatment. A total of 18 677 differentially expressed genes (DEGs) were induced by MeJA treatment, of which 4535 were up-regulated and 14 142 were down-regulated compared with controls. These DEGs were associated with 125 metabolic pathways. In addition to various common primary and secondary metabolic pathways, several secondary metabolic pathways related to components with significant pharmacological effects were enriched by MeJA, including arachidonic acid metabolism, linoleic acid metabolism, and stilbenoid biosynthesis. The MeJA-induced transcriptome changes uncovered in this study provide a solid foundation for future study of functional genes controlling effective components in secondary metabolic pathways of P. multiflorum. PMID:26642186

  7. Transcriptome changes in Polygonum multiflorum Thunb. roots induced by methyl jasmonate* #

    PubMed Central

    Liu, Hong-chang; Wu, Wei; Hou, Kai; Chen, Jun-wen; Zhao, Zhi

    2015-01-01

    Transcriptome profiling has been widely used to analyze transcriptomic variation in plants subjected to abiotic or biotic stresses. Although gene expression changes induced by methyl jasmonate (MeJA) have been profiled in several plant species, no information is available on the MeJA-triggered transcriptome response of Polygonum multiflorum Thunb., a species with highly valuable medicinal properties. In this study, we used transcriptome profiling to investigate transcriptome changes in roots of P. multiflorum seedlings subjected to a 0.25 mmol/L-MeJA root irrigation treatment. A total of 18 677 differentially expressed genes (DEGs) were induced by MeJA treatment, of which 4535 were up-regulated and 14 142 were down-regulated compared with controls. These DEGs were associated with 125 metabolic pathways. In addition to various common primary and secondary metabolic pathways, several secondary metabolic pathways related to components with significant pharmacological effects were enriched by MeJA, including arachidonic acid metabolism, linoleic acid metabolism, and stilbenoid biosynthesis. The MeJA-induced transcriptome changes uncovered in this study provide a solid foundation for future study of functional genes controlling effective components in secondary metabolic pathways of P. multiflorum. PMID:26642186

  8. Deep sequencing reveals transcriptome re-programming of Polygonum multiflorum thunb. roots to the elicitation with methyl jasmonate.

    PubMed

    Liu, Hongchang; Wu, Wei; Hou, Kai; Chen, Junwen; Zhao, Zhi

    2016-02-01

    The phytohormone methyl jasmonate (MeJA) has been successfully used as an effective elicitor to enhance production of stilbenoid which is induced in plants as a secondary metabolite possibly in defense against herbivores and pathogens. However, the mechanism of MeJA-mediated stilbenoid biosynthesis remains unclear. Genomic information for Polygonum multiflorum Thunb. (P. multiflorum) is currently unavailable. To obtain insight into the global regulation mechanism of MeJA in the steady state of stilbene glucoside production (26 h after MeJA elicitation), especially on stilbene glucoside biosynthesis, we sequenced the transcriptomes of MeJA-treated and untreated P. multiflorum roots and obtained more than 51 million clean reads, from which 79,565 unigenes were obtained by de novo assembly. 56,972 unigenes were annotated against databases including Nr, Nt, Swiss-Prot, KEGG and COG. 18,677 genes expressed differentially between untreated and treated roots. Expression level analysis indicated that a large number of genes were associated with plant-pathogen interaction, plant hormone signal transduction, stilbenoid backbone biosynthesis, and phenylpropanoid biosynthesis. 15 known genes involved in the biosynthesis of stilbenoid backbone were found with 7 genes showing increased transcript abundance following elicitation of MeJA. The significantly up (down)-regulated changes of 70 genes in stilbenoid biosynthesis were validated by qRT-PCR assays and PCR product sequencing. According to the expression changes and the previously proposed enzyme functions, multiple candidates for the unknown steps in stilbene glucoside biosynthesis were identified. We also found some genes putatively involved in the transcription factors. This comprehensive description of gene expression information could greatly facilitate our understanding of the molecular mechanisms of MeJA-mediated stilbenoid biosynthesis in P. multiflorum roots. Our results shed new light on the global regulation

  9. Remodeling of Leaf Cellular Glycerolipid Composition under Drought and Re-hydration Conditions in Grasses from the Lolium-Festuca Complex

    PubMed Central

    Perlikowski, Dawid; Kierszniowska, Sylwia; Sawikowska, Aneta; Krajewski, Paweł; Rapacz, Marcin; Eckhardt, Änne; Kosmala, Arkadiusz

    2016-01-01

    Drought tolerant plant genotypes are able to maintain stability and integrity of cellular membranes in unfavorable conditions, and to regenerate damaged membranes after stress cessation. The profiling of cellular glycerolipids during drought stress performed on model species such as Arabidopsis thaliana does not fully cover the picture of lipidome in monocots, including grasses. Herein, two closely related introgression genotypes of Lolium multiflorum (Italian ryegrass) × Festuca arundinacea (tall fescue) were used as a model for other grass species to describe lipid rearrangements during drought and re-hydration. The genotypes differed in their level of photosynthetic capacity during drought, and in their capacity for membrane regeneration after stress cessation. A total of 120 lipids, comprising the classes of monogalactosyldiacyloglycerol, digalactosyldiacyloglycerol, sulfoquinovosyldiacylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, diacylglicerol, and triacylglicerol, were analyzed. The results clearly showed that water deficit had a significant impact on lipid metabolism in studied forage grasses. It was revealed that structural and metabolic lipid species changed their abundance during drought and re-watering periods and some crucial genotype-dependent differences were also observed. The introgression genotype characterized by an ability to regenerate membranes after re-hydration demonstrated a higher accumulation level of most chloroplast and numerous extra-chloroplast membrane lipid species at the beginning of drought. Furthermore, this genotype also revealed a significant reduction in the accumulation of most chloroplast lipids after re-hydration, compared with the other introgression genotype without the capacity for membrane regeneration. The potential influence of observed lipidomic alterations on a cellular membrane stability and photosynthetic capacity, are discussed

  10. Remodeling of Leaf Cellular Glycerolipid Composition under Drought and Re-hydration Conditions in Grasses from the Lolium-Festuca Complex.

    PubMed

    Perlikowski, Dawid; Kierszniowska, Sylwia; Sawikowska, Aneta; Krajewski, Paweł; Rapacz, Marcin; Eckhardt, Änne; Kosmala, Arkadiusz

    2016-01-01

    Drought tolerant plant genotypes are able to maintain stability and integrity of cellular membranes in unfavorable conditions, and to regenerate damaged membranes after stress cessation. The profiling of cellular glycerolipids during drought stress performed on model species such as Arabidopsis thaliana does not fully cover the picture of lipidome in monocots, including grasses. Herein, two closely related introgression genotypes of Lolium multiflorum (Italian ryegrass) × Festuca arundinacea (tall fescue) were used as a model for other grass species to describe lipid rearrangements during drought and re-hydration. The genotypes differed in their level of photosynthetic capacity during drought, and in their capacity for membrane regeneration after stress cessation. A total of 120 lipids, comprising the classes of monogalactosyldiacyloglycerol, digalactosyldiacyloglycerol, sulfoquinovosyldiacylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, diacylglicerol, and triacylglicerol, were analyzed. The results clearly showed that water deficit had a significant impact on lipid metabolism in studied forage grasses. It was revealed that structural and metabolic lipid species changed their abundance during drought and re-watering periods and some crucial genotype-dependent differences were also observed. The introgression genotype characterized by an ability to regenerate membranes after re-hydration demonstrated a higher accumulation level of most chloroplast and numerous extra-chloroplast membrane lipid species at the beginning of drought. Furthermore, this genotype also revealed a significant reduction in the accumulation of most chloroplast lipids after re-hydration, compared with the other introgression genotype without the capacity for membrane regeneration. The potential influence of observed lipidomic alterations on a cellular membrane stability and photosynthetic capacity, are discussed

  11. Germplasm dynamics: the role of ecotypic diversity in shaping the patterns of genetic variation in Lolium perenne.

    PubMed

    Blackmore, T; Thorogood, D; Skøt, L; McMahon, R; Powell, W; Hegarty, M

    2016-01-01

    Perennial ryegrass (Lolium perenne) is the most widely grown temperate grass species globally. Intensive plant breeding in ryegrass compared to many other crops species is a relatively recent exercise (last 100 years) and provides an interesting experimental system to trace the extent, impact and trajectory of undomesticated ecotypic variation represented in modern ryegrass cultivars. To explore germplasm dynamics in Lolium perenne, 2199 SNPs were genotyped in 716 ecotypes sampled from 90 European locations together with 249 cultivars representing 33 forage/amenity accessions. In addition three pseudo-cross mapping populations (450 individual recombinants) were genotyped to create a consensus genetic linkage map. Multivariate analyses revealed strong differentiation between cultivars with a small proportion of the ecotypic variation captured in improved cultivars. Ryegrass cultivars generated as part of a recurrent selection programme (RSP) are strongly associated with a small number of geographically localised Italian ecotypes which were among the founders of the RSP. Changes in haplotype frequency revealed signatures of selection in genes putatively involved in water-soluble carbohydrate (WSC) accumulation (a trait selected in the RSP). Retrospective analysis of germplasm in breeding programmes (germplasm dynamics) provides an experimental framework for the identification of candidate genes for novel traits such as WSC accumulation in ryegrass. PMID:26935901

  12. Germplasm dynamics: the role of ecotypic diversity in shaping the patterns of genetic variation in Lolium perenne

    PubMed Central

    Blackmore, T.; Thorogood, D.; Skøt, L.; McMahon, R.; Powell, W.; Hegarty, M.

    2016-01-01

    Perennial ryegrass (Lolium perenne) is the most widely grown temperate grass species globally. Intensive plant breeding in ryegrass compared to many other crops species is a relatively recent exercise (last 100 years) and provides an interesting experimental system to trace the extent, impact and trajectory of undomesticated ecotypic variation represented in modern ryegrass cultivars. To explore germplasm dynamics in Lolium perenne, 2199 SNPs were genotyped in 716 ecotypes sampled from 90 European locations together with 249 cultivars representing 33 forage/amenity accessions. In addition three pseudo-cross mapping populations (450 individual recombinants) were genotyped to create a consensus genetic linkage map. Multivariate analyses revealed strong differentiation between cultivars with a small proportion of the ecotypic variation captured in improved cultivars. Ryegrass cultivars generated as part of a recurrent selection programme (RSP) are strongly associated with a small number of geographically localised Italian ecotypes which were among the founders of the RSP. Changes in haplotype frequency revealed signatures of selection in genes putatively involved in water-soluble carbohydrate (WSC) accumulation (a trait selected in the RSP). Retrospective analysis of germplasm in breeding programmes (germplasm dynamics) provides an experimental framework for the identification of candidate genes for novel traits such as WSC accumulation in ryegrass. PMID:26935901

  13. Ultrasonic-assisted extraction, structure and antitumor activity of polysaccharide from Polygonum multiflorum.

    PubMed

    Zhu, Weili; Xue, Xiaoping; Zhang, Zhanjun

    2016-10-01

    Polygonum multiflorum is a popular Chinese herbal medicine with various pharmacological functions. In this study, the ultrasonic-assisted extraction condition, structural characterization and antitumor activity of a polysaccharide from roots of P. multiflorum were investigated. The ultrasonic-assisted extraction condition was optimized by single-factor experiments and response surface methodology. Results showed that the maximum extraction yield (5.49%) was obtained at ultrasonic power 158W, extraction temperature 62°C, extraction time 80min and ratio of water to material 20mL/g. The obtained crude polysaccharides were further purified to afford a neutral and an acidic fraction. The structure of the main neutral polysaccharide (named PPS with molecular weight of 3.26×10(5)Da) was characterized as a linear (1→6)-α-d-glucan by gas chromatography, Fourier transform-infrared spectroscopy, methylation analysis, 1D and 2D nuclear magnetic resonance. At the concentration of 400μg/mL, the inhibitory ratios of PPS on HepG-2 and BGC-823 cells were 53.35% and 38.58%, respectively. Results suggested this polysaccharide could be a potential natural antitumor agent. PMID:27212220

  14. Polygonum multiflorum Decreases Airway Allergic Symptoms in a Murine Model of Asthma.

    PubMed

    Lee, Chen-Chen; Lee, Yueh-Lun; Wang, Chien-N; Tsai, Hsing-Chuan; Chiu, Chun-Lung; Liu, Leroy F; Lin, Hung-Yun; Wu, Reen

    2016-01-01

    The root of Polygonum multiflorum (also called He-Shou-Wu in Chinese) is a common herb and medicinal food in Asia used for its anti-aging properties. Our study investigated the therapeutic potential of an extract of the root of Polygonum multiflorum (PME) in allergic asthma by using a mouse model. Feeding of 0.5 and 1 mg/mouse PME inhibited ovalbumin (OVA)-induced allergic asthma symptoms, including airway inflammation, mucus production, and airway hyper-responsiveness (AHR), in a dose-dependent manner. To discern PME's mechanism of action, we examined the profile and cytokine production of inflammatory cells in bronchial alveolar lavage fluid (BALF). We found that eosinophils, the main inflammatory cell infiltrate in the lung of OVA-immunized mice, significantly decreased after PME treatment. Th2 cytokine levels, including interleukin (IL)-4, IL-5, IL-13, eotaxin, and the proinflammatory cytokine tumor necrosis factor (TNF)-[Formula: see text], decreased in PME-treated mice. Elevated mRNA expression of Th2 transcription factor GATA-3 in the lung tissue was also inhibited after oral feeding of PME in OVA-immunized mice. Thus, we conclude that PME produces anti-asthma activity through the inhibition of Th2 cell activation. PMID:26916919

  15. A novel method to analyze hepatotoxic components in Polygonum multiflorum using ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry.

    PubMed

    Lin, Longfei; Lin, Hongmei; Zhang, Miao; Ni, Boran; Yin, Xingbin; Qu, Changhai; Ni, Jian

    2015-12-15

    Polygonum multiflorum, called Heshouwu in China, is a traditional Chinese medicine used to treat various diseases. However, the administration of P. multiflorum (PM) and P. multiflorum Praeparata (PMP) causes numerous adverse effects. This study sought to analyze the toxic components of PM using ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS), and their hepatotoxicity in L02 human liver cells. Toxicity was evaluated by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), lactate dehydrogenase (LDH) leakage, and liver enzyme secretion (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]) assays. Furthermore, UPLC-Q-TOF/MS, Progenesis QI, and Makerlynx XS software analyses were used to differentiate extracts and analyze the toxic components. The order of toxicity was P. multiflorum ethanol extract (PME)>P. multiflorum water extract (PMW)>P. multiflorum Praeparata ethanol extract (PMPE)>P. multiflorum Praeparata water extract (PMPW), which was determined by MTT assay, LDH leakage, and liver enzyme secretion levels. The analysis methods suggest that PM toxicity may be associated with anthraquinone, emodin-O-(malonyl)-hex, emodin-O-glc, emodin, emodin-8-O-glc, emodin-O-(acetyl)-hex, and emodin-O-hex-sulphate. The toxic mechanisms of these components require further study. PMID:26135484

  16. Chemical constituents from the root of Polygonum multiflorum and their soluble epoxide hydrolase inhibitory activity.

    PubMed

    Sun, Ya Nan; Li, Wei; Kim, Jang Hoon; Yan, Xi Tao; Kim, Ji Eun; Yang, Seo Young; Kim, Young Ho

    2015-06-01

    Fourteen compounds were isolated from a methanol extract of Polygonum multiflorum roots, and their structures were elucidated by comparing spectroscopic data to published spectra. The inhibitory effects of the isolated compounds on soluble epoxide hydrolase (sEH) were then evaluated. Compounds 1-7 inhibited sEH activity potently, with IC50 values ranging from 6.2 ± 0.5 to 48.6 ± 3.1 μM. Moreover, a kinetic analysis of compounds 1-7 revealed that the inhibitory actions of compounds 1, 3 and 4 were non-competitive, whereas those of compounds 2 and 5-7 were mixed-type. PMID:25413971

  17. Cross-resistance to herbicides in annual ryegrass (lolium rigidum)

    SciTech Connect

    Christopher, J.T.; Powles, S.B.; Liljegren, D.R.; Holtum, J.A.M. )

    1991-04-01

    Lolium rigidum Gaud. biotype SLR31 is resistant to the herbicide diclofop-methyl and cross-resistant to several sulfonylurea herbicides. Wheat and the cross-resistant ryegrass exhibit similar patterns of resistance to sulfonylurea herbicides, suggesting that the mechanism of resistance may be similar. Cross-resistant ryegrass is also resistant to the wheat-selective imidazolinone herbicide imazamethabenz. The cross-resistant biotype SLR31 metabolized (phenyl-U-{sup 14}C)chlorsulfuron at a faster rate than a biotype which is susceptible to both diclofop-methyl and chlorsulfuron. A third biotype which is resistant to diclofop-methyl but not to chlorsulfuron metabolized chlorsulfuron at the same rate as the susceptible biotype. The increased metabolism of chlorsulfuron observed in the cross-resistant biotype is, therefore, correlated with the patterns of resistance observed in these L. rigidum biotypes. During high performance liquid chromatography analysis the major metabolite of chlorsulfuron in both susceptible and cross-resistant ryegrass coeluted with the major metabolite produced in wheat. The major product is clearly different from the major product in the tolerant dicot species, flax (Linium usitatissimum). The elution pattern of metabolites of chlorsulfuron was the same for both the susceptible and cross-resistant ryegrass but the cross-resistant ryegrass metabolized chlorsulfuron more rapidly. The investigation of the dose response to sulfonylurea herbicides at the whole plant level and the study of the metabolism of chlorsulfuron provide two independent sets of data which both suggest that the resistance to chlorsulfuron in cross-resistant ryegrass biotype SLR31 involves a wheat-like detoxification system.

  18. Evaluation of reference genes for quantitative RT-PCR in Lolium temulentum under abiotic stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lolium temulentum is a valuable model grass species for the study of stress in forage and turf grasses. Gene expression analysis by quantitative real time RT-PCR relies on the use of proper internal standards. The aim of this study was to identify and evaluate reference genes for use in real-time q...

  19. Genotype _ environment interactions for forage yield of Lolium perenne L. sward plots in Ireland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lolium perenne L. (perennial ryegrass) is by far the most widely sown grass species in Ireland. Genotype by environment (G by E) interactions are a frequent occurrence in forage yield evaluations. The objectives were to determine (i) the nature and relative magnitudes of the pertinent G by E interac...

  20. Transcriptome response in different tissues of Lolium arundinaceum to the fungal endophyte Epichloe coenophiala

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tall fescue (Lolium arundinaceum) plants symbiotic with the endophytic fungus, Epichloe coenophiala , (E+), have been shown to have better survivability and persistence than plants lacking the endophyte (E-). To understand more about the grass-endophyte interactions and how endophyte affects the ho...

  1. Transcriptome response of Lolium arundinaceum to the fungal endophyte Epichloe coenophiala

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tall fescue (Lolium arundinaceum) is one of the principal cool-season species used as a forage and turf within the USA. A number of benefits associated with the persistence of tall fescue have been attributed to the presence of its seed-transmissible symbiont, the fungal endophyte Epichloë coenophi...

  2. Abiotic stresses activate a MAPkinase in the model grass species Lolium temulentum L.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forage and turf grasses are utilized in diverse environments which exposes them to a variety of abiotic stresses, however very little is known concerning the perception or molecular responses to these various stresses. In the model grass species Lolium temulentum (Lt), a 46 kDa mitogen-activated pro...

  3. Evaluation of reference genes for quantitative RT-PCR in Lolium perenne

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantitative real-time RT-PCR provides an important tool for analyzing gene expression if proper internal standards are used. The aim of this study was to identify and evaluate reference genes for use in real-time quantitative RT-PCR in perennial ryegrass (Lolium perenne L.) during plant developmen...

  4. Lolium latent virus (Alphaflexiviridae) coat proteins: expression and functions in infected plant tissue

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Lolium latent virus (LoLV, Lolavirus, Alphaflexiviridae) viral genome is encapsidated by two carboxy-coterminal coat protein (CP) variants (about 28 and 33 kDa), in equimolar proportion. The CP ORF contains two 5'-proximal AUGs, encoding Met 1 and Met 49, respectively promoting translation of th...

  5. EST-derived SSR markers used as anchor loci for the construction of a consensus linkage map in ryegrass (Lolium spp.)

    PubMed Central

    2010-01-01

    Background Genetic markers and linkage mapping are basic prerequisites for marker-assisted selection and map-based cloning. In the case of the key grassland species Lolium spp., numerous mapping populations have been developed and characterised for various traits. Although some genetic linkage maps of these populations have been aligned with each other using publicly available DNA markers, the number of common markers among genetic maps is still low, limiting the ability to compare candidate gene and QTL locations across germplasm. Results A set of 204 expressed sequence tag (EST)-derived simple sequence repeat (SSR) markers has been assigned to map positions using eight different ryegrass mapping populations. Marker properties of a subset of 64 EST-SSRs were assessed in six to eight individuals of each mapping population and revealed 83% of the markers to be polymorphic in at least one population and an average number of alleles of 4.88. EST-SSR markers polymorphic in multiple populations served as anchor markers and allowed the construction of the first comprehensive consensus map for ryegrass. The integrated map was complemented with 97 SSRs from previously published linkage maps and finally contained 284 EST-derived and genomic SSR markers. The total map length was 742 centiMorgan (cM), ranging for individual chromosomes from 70 cM of linkage group (LG) 6 to 171 cM of LG 2. Conclusions The consensus linkage map for ryegrass based on eight mapping populations and constructed using a large set of publicly available Lolium EST-SSRs mapped for the first time together with previously mapped SSR markers will allow for consolidating existing mapping and QTL information in ryegrass. Map and markers presented here will prove to be an asset in the development for both molecular breeding of ryegrass as well as comparative genetics and genomics within grass species. PMID:20712870

  6. Liver Damage Associated with Polygonum multiflorum Thunb.: A Systematic Review of Case Reports and Case Series.

    PubMed

    Lei, Xiang; Chen, Jing; Ren, Jingtian; Li, Yan; Zhai, Jingbo; Mu, Wei; Zhang, Li; Zheng, Wenke; Tian, Guihua; Shang, Hongcai

    2015-01-01

    Objective. To summarize the characteristics and analysis of relevant factors and to give references for prevention and further study of liver damage associated with Polygonum multiflorum Thunb. (HSW), we provide a systematic review of case reports and case series about liver damage associated with HSW. Methods. An extensive search of 6 medical databases was performed up to June 2014. Case reports and case series involving liver damage associated with HSW were included. Results. This review covers a total of 450 cases in 76 articles. HSW types included raw and processed HSW decoction pieces and many Chinese patent medicines that contain HSW. Symptoms of liver damage occur mostly a month or so after taking the medicine, mainly including jaundice, fatigue, anorexia, and yellow or tawny urine. Of the 450 patients, two cases who received liver transplantation and seven who died, the remaining 441 cases recovered or had liver function improvement after discontinuing HSW products and conservative care. Conclusion. HSW causes liver toxicity and may cause liver damage in different degrees and even lead to death; most of them are much related to long-term and overdose of drugs. Liver damage associated with HSW is reversible, and, after active treatment, the majority can be cured. People should be alert to liver damage when taking HSW preparations. PMID:25648693

  7. Liver Damage Associated with Polygonum multiflorum Thunb.: A Systematic Review of Case Reports and Case Series

    PubMed Central

    Lei, Xiang; Chen, Jing; Ren, Jingtian; Li, Yan; Zhai, Jingbo; Mu, Wei; Zhang, Li; Zheng, Wenke; Tian, Guihua; Shang, Hongcai

    2015-01-01

    Objective. To summarize the characteristics and analysis of relevant factors and to give references for prevention and further study of liver damage associated with Polygonum multiflorum Thunb. (HSW), we provide a systematic review of case reports and case series about liver damage associated with HSW. Methods. An extensive search of 6 medical databases was performed up to June 2014. Case reports and case series involving liver damage associated with HSW were included. Results. This review covers a total of 450 cases in 76 articles. HSW types included raw and processed HSW decoction pieces and many Chinese patent medicines that contain HSW. Symptoms of liver damage occur mostly a month or so after taking the medicine, mainly including jaundice, fatigue, anorexia, and yellow or tawny urine. Of the 450 patients, two cases who received liver transplantation and seven who died, the remaining 441 cases recovered or had liver function improvement after discontinuing HSW products and conservative care. Conclusion. HSW causes liver toxicity and may cause liver damage in different degrees and even lead to death; most of them are much related to long-term and overdose of drugs. Liver damage associated with HSW is reversible, and, after active treatment, the majority can be cured. People should be alert to liver damage when taking HSW preparations. PMID:25648693

  8. Beneficial Effects of Polygonum multiflorum on Hippocampal Neuronal Cells and Mouse Focal Cerebral Ischemia.

    PubMed

    Ahn, Sung Min; Kim, Yu Ri; Kim, Ha Neui; Shin, Hwa Kyoung; Choi, Byung Tae

    2015-01-01

    Beneficial effects of the water extract of Polygonum multiflorum (WEPM) and their mechanisms were investigated in HT22 hippocampal cells and hippocampus of middle cerebral artery occlusion (MCAO) mice. In HT22 cells against glutamate-induced oxidative stress, pretreatment with WEPM resulted in significantly reduced apoptotic neuronal death. Pretreatment with WEPM resulted in the suppression of ROS accumulation in connection with cellular Ca (2+) level after exposure to glutamate. Treatment with glutamate alone led to suppressed protein level of mature brain-derived neurotrophic factor (BDNF) and phosphorylated cAMP response element binding protein (CREB); however, pretreatment with either WEPM or anti-oxidant N-acetyl-ʟ-cysteine (NAC) resulted in the significant enhancement of levels of these proteins. In addition, levels of mature BDNF expression and CREB phosphorylation were increased by combined treatment with WEPM, NAC, and intracellular Ca (2+) inhibitor BAPTA compared to other treatment groups. In MCAO mice, we confirmed the critical role of mature BDNF expression and CREB phosphorylation by WEPM in the neurons of the hippocampus. Our results suggest that WEPM mainly exerted beneficial effects on hippocampal neurons through the suppression of ROS accumulation and up-regulation of mature BDNF expression and CREB phosphorylation. PMID:26119951

  9. Impact of no-till cover cropping of Italian ryegrass on above and below ground faunal communities inhabiting a soybean field with special emphasis on soybean cyst nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two field trials were conducted in Maryland to evaluate the ability of an Italian ryegrass (IR) (Lolium multiflorum) cover crop in a no-till soybean (Glycine max) planting to 1) reduce populations of plant-parasitic nematodes (i.e., the soybean cyst nematode, Heterodera glycines and lesion nematodes...

  10. Association of candidate genes with flowering time and water-soluble carbohydrate content in Lolium perenne (L.).

    PubMed

    Skøt, Leif; Humphreys, Jan; Humphreys, Mervyn O; Thorogood, Danny; Gallagher, Joe; Sanderson, Ruth; Armstead, Ian P; Thomas, Ian D

    2007-09-01

    We describe a candidate gene approach for associating SNPs with variation in flowering time and water-soluble carbohydrate (WSC) content and other quality traits in the temperate forage grass species Lolium perenne. Three analysis methods were used, which took the significant population structure into account. First, a linear mixed model was used enabling a structured association analysis to be incorporated with the nine populations identified in the structure analysis as random variables. Second, a within-population analysis of variance was performed. Third, a tree-scanning method was used, in which haplotype trees were associated with phenotypes on the basis of inferred haplotypes. Analysis of variance within populations identified several associations between WSC, nitrogen (N), and dry matter digestibility with allelic variants within an alkaline invertase candidate gene LpcAI. These associations were only detected in material harvested in one of the two years. By contrast, consistent associations between the L. perenne homolog (LpHD1) of the rice photoperiod control gene HD1 and flowering time were identified. One SNP, in the immediate upstream region of the LpHD1 coding sequence (C-4443-A), was significant in the linear mixed model. Within-population analysis of variance and tree-scanning analysis confirmed and extended this result to the 2118 polymorphisms in some of the populations. The merits of the tree-scanning method are compared to the single SNP analysis. The potential usefulness of the 4443 SNP in marker-assisted selection is currently being evaluated in test crosses of genotypes from this work with turf-grass varieties. PMID:17660575

  11. Association of Candidate Genes With Flowering Time and Water-Soluble Carbohydrate Content in Lolium perenne (L.)

    PubMed Central

    Skøt, Leif; Humphreys, Jan; Humphreys, Mervyn O.; Thorogood, Danny; Gallagher, Joe; Sanderson, Ruth; Armstead, Ian P.; Thomas, Ian D.

    2007-01-01

    We describe a candidate gene approach for associating SNPs with variation in flowering time and water-soluble carbohydrate (WSC) content and other quality traits in the temperate forage grass species Lolium perenne. Three analysis methods were used, which took the significant population structure into account. First, a linear mixed model was used enabling a structured association analysis to be incorporated with the nine populations identified in the structure analysis as random variables. Second, a within-population analysis of variance was performed. Third, a tree-scanning method was used, in which haplotype trees were associated with phenotypes on the basis of inferred haplotypes. Analysis of variance within populations identified several associations between WSC, nitrogen (N), and dry matter digestibility with allelic variants within an alkaline invertase candidate gene LpcAI. These associations were only detected in material harvested in one of the two years. By contrast, consistent associations between the L. perenne homolog (LpHD1) of the rice photoperiod control gene HD1 and flowering time were identified. One SNP, in the immediate upstream region of the LpHD1 coding sequence (C-4443-A), was significant in the linear mixed model. Within-population analysis of variance and tree-scanning analysis confirmed and extended this result to the 2118 polymorphisms in some of the populations. The merits of the tree-scanning method are compared to the single SNP analysis. The potential usefulness of the 4443 SNP in marker-assisted selection is currently being evaluated in test crosses of genotypes from this work with turf-grass varieties. PMID:17660575

  12. Screening for biomarkers of liver injury induced by Polygonum multiflorum: a targeted metabolomic study

    PubMed Central

    Dong, Qin; Li, Na; Li, Qi; Zhang, Cong-En; Feng, Wu-Wen; Li, Guang-Quan; Li, Rui-Yu; Tu, Can; Han, Xue; Bai, Zhao-Fang; Zhang, Ya-Ming; Niu, Ming; Ma, Zhi-Jie; Xiao, Xiao-He; Wang, Jia-Bo

    2015-01-01

    Heshouwu (HSW), the dry roots of Polygonum multiflorum, a classical traditional Chinese medicine is used as a tonic for a wide range of conditions, particularly those associated with aging. However, it tends to be taken overdose or long term in these years, which has resulted in liver damage reported in many countries. In this study, the indicative roles of nine bile acids (BAs) were evaluated to offer potential biomarkers for HSW induced liver injury. Nine BAs including cholic acid (CA) and chenodeoxycholic acid (CDCA), taurocholic acid (TCA), glycocholic acid (GCA), glycochenodeoxycholic acid (GCDCA), deoxycholic acid (DCA), glycodeoxycholic acid (GDCA), ursodeoxycholic acid (UDCA), and hyodeoxycholic acid (HDCA) in rat bile and serum were detected by a developed LC-MS method after 42 days treatment. Partial least square-discriminate analysis (PLS-DA) was applied to evaluate the indicative roles of the nine BAs, and metabolism of the nine BAs was summarized. Significant change was observed for the concentrations of nine BAs in treatment groups compared with normal control; In the PLS-DA plots of nine BAs in bile, normal control and raw HSW groups were separately clustered and could be clearly distinguished, GDCA was selected as the distinguished components for raw HSW overdose treatment group. In the PLS-DA plots of nine BAs in serum, the normal control and raw HSW overdose treatment group were separately clustered and could be clearly distinguished, and HDCA was selected as the distinguished components for raw HSW overdose treatment group. The results indicated the perturbation of nine BAs was associated with HSW induced liver injury; GDCA in bile, as well as HDCA in serum could be selected as potential biomarkers for HSW induced liver injury; it also laid the foundation for the further search on the mechanisms of liver injury induced by HSW. PMID:26483689

  13. Screening for biomarkers of liver injury induced by Polygonum multiflorum: a targeted metabolomic study.

    PubMed

    Dong, Qin; Li, Na; Li, Qi; Zhang, Cong-En; Feng, Wu-Wen; Li, Guang-Quan; Li, Rui-Yu; Tu, Can; Han, Xue; Bai, Zhao-Fang; Zhang, Ya-Ming; Niu, Ming; Ma, Zhi-Jie; Xiao, Xiao-He; Wang, Jia-Bo

    2015-01-01

    Heshouwu (HSW), the dry roots of Polygonum multiflorum, a classical traditional Chinese medicine is used as a tonic for a wide range of conditions, particularly those associated with aging. However, it tends to be taken overdose or long term in these years, which has resulted in liver damage reported in many countries. In this study, the indicative roles of nine bile acids (BAs) were evaluated to offer potential biomarkers for HSW induced liver injury. Nine BAs including cholic acid (CA) and chenodeoxycholic acid (CDCA), taurocholic acid (TCA), glycocholic acid (GCA), glycochenodeoxycholic acid (GCDCA), deoxycholic acid (DCA), glycodeoxycholic acid (GDCA), ursodeoxycholic acid (UDCA), and hyodeoxycholic acid (HDCA) in rat bile and serum were detected by a developed LC-MS method after 42 days treatment. Partial least square-discriminate analysis (PLS-DA) was applied to evaluate the indicative roles of the nine BAs, and metabolism of the nine BAs was summarized. Significant change was observed for the concentrations of nine BAs in treatment groups compared with normal control; In the PLS-DA plots of nine BAs in bile, normal control and raw HSW groups were separately clustered and could be clearly distinguished, GDCA was selected as the distinguished components for raw HSW overdose treatment group. In the PLS-DA plots of nine BAs in serum, the normal control and raw HSW overdose treatment group were separately clustered and could be clearly distinguished, and HDCA was selected as the distinguished components for raw HSW overdose treatment group. The results indicated the perturbation of nine BAs was associated with HSW induced liver injury; GDCA in bile, as well as HDCA in serum could be selected as potential biomarkers for HSW induced liver injury; it also laid the foundation for the further search on the mechanisms of liver injury induced by HSW. PMID:26483689

  14. Complete Chloroplast Genome Sequence of a Major Allogamous Forage Species, Perennial Ryegrass (Lolium perenne L.)

    PubMed Central

    Diekmann, Kerstin; Hodkinson, Trevor R.; Wolfe, Kenneth H.; van den Bekerom, Rob; Dix, Philip J.; Barth, Susanne

    2009-01-01

    Lolium perenne L. (perennial ryegrass) is globally one of the most important forage and grassland crops. We sequenced the chloroplast (cp) genome of Lolium perenne cultivar Cashel. The L. perenne cp genome is 135 282 bp with a typical quadripartite structure. It contains genes for 76 unique proteins, 30 tRNAs and four rRNAs. As in other grasses, the genes accD, ycf1 and ycf2 are absent. The genome is of average size within its subfamily Pooideae and of medium size within the Poaceae. Genome size differences are mainly due to length variations in non-coding regions. However, considerable length differences of 1–27 codons in comparison of L. perenne to other Poaceae and 1–68 codons among all Poaceae were also detected. Within the cp genome of this outcrossing cultivar, 10 insertion/deletion polymorphisms and 40 single nucleotide polymorphisms were detected. Two of the polymorphisms involve tiny inversions within hairpin structures. By comparing the genome sequence with RT–PCR products of transcripts for 33 genes, 31 mRNA editing sites were identified, five of them unique to Lolium. The cp genome sequence of L. perenne is available under Accession number AM777385 at the European Molecular Biology Laboratory, National Center for Biotechnology Information and DNA DataBank of Japan. PMID:19414502

  15. Development of a Genomic Microsatellite Library in Perennial Ryegrass (Lolium perenne) and its Use in Trait Mapping

    PubMed Central

    King, J.; Thorogood, D.; Edwards, K. J.; Armstead, I. P.; Roberts, L.; Skøt, K.; Hanley, Z.; King, I. P.

    2008-01-01

    Background and Aims Perennial ryegrass (Lolium perenne) is one of the key forage and amenity grasses throughout the world. In the UK it accounts for 70 % of all agricultural land use with an estimated farm gate value of £6 billion per annum. However, in terms of the genetic resources available, L. perenne has lagged behind other major crops in Poaceae. The aim of this project was therefore the construction of a microsatellite-enriched genomic library for L. perenne to increase the number of genetic markers available for both marker-assisted selection in breeding programmes and gene isolation. Methods Primers for 229 non-redundant microsatellite markers were designed and used to screen two L. perenne genotypes, one amenity and one forage. Of the 229 microsatellites, 95 were found to show polymorphism between amenity and forage genotypes. A selection of microsatellite primers was selected from these 95 and used to screen two mapping populations derived from intercrossing and backcrossing the two forage and amenity grass genotypes. Key Results and Conclusions The utility of the resulting genetic maps for analysis of the genetic control of target traits was demonstrated by the mapping of genes associated with heading date to linkage groups 4 and 7. PMID:18281692

  16. Comparative Metabolite Fingerprinting of the Rumen System during Colonisation of Three Forage Grass (Lolium perenne L.) Varieties

    PubMed Central

    Kingston-Smith, Alison H.; Davies, Teri E.; Rees Stevens, Pauline; Mur, Luis A. J.

    2013-01-01

    The rumen microbiota enable ruminants to degrade complex ligno-cellulosic compounds to produce high quality protein for human consumption. However, enteric fermentation by domestic ruminants generates negative by-products: greenhouse gases (methane) and environmental nitrogen pollution. The current lack of cultured isolates representative of the totality of rumen microbial species creates an information gap about the in vivo function of the rumen microbiota and limits our ability to apply predictive biology for improvement of feed for ruminants. In this work we took a whole ecosystem approach to understanding how the metabolism of the microbial population responds to introduction of its substrate. Fourier Transform Infra Red (FTIR) spectroscopy-based metabolite fingerprinting was used to discriminate differences in the plant-microbial interactome of the rumen when using three forage grass varieties (Lolium perenne L. cv AberDart, AberMagic and Premium) as substrates for microbial colonisation and fermentation. Specific examination of spectral regions associated with fatty acids, amides, sugars and alkanes indicated that although the three forages were apparently similar by traditional nutritional analysis, patterns of metabolite flux within the plant-microbial interactome were distinct and plant genotype dependent. Thus, the utilisation pattern of forage nutrients by the rumen microbiota can be influenced by subtleties determined by forage genotypes. These data suggest that our interactomic approach represents an important means to improve forages and ultimately the livestock environment. PMID:24312434

  17. [Effects of ryegrass (Lolium perenne) root exudates dose on pyrene degradation and soil microbes in pyrene-contaminated soil].

    PubMed

    Xie, Xiao-mei; Liao, Min; Yang, Jing

    2011-10-01

    By simulating a gradually decreasing concentration of root exudates with the distance away from root surface in rhizosphere, this paper studied the effects of ryegrass (Lolium perenne) root exudates dose on the pyrene degradation and microbial ecological characteristics in a pyrene-contaminated soil. It was observed that with the increasing dose of ryegrass root exudates, the residual amount of soil pyrene changed nonlinearly, i. e. , increased after an initial decrease. When the root exudates dose was 32.75 mg kg(-1) of total organic carbon, the residual pyrene was the minimum, indicating that the root exudates at this dose stimulated pyrene degradation significantly. In the meantime, soil microbial biomass carbon and microbial quotient had an opposite trend, suggesting the close relationship between pyrene degradation and soil microbes. In the test soil, microbial community was dominated by bacteria, and the bacteria had the same variation trend as the pyrene degradation, which indicated that the pyrene was degraded mainly by bacteria, and the effects of root exudates on pyrene degradation were mainly carried out through the effects on bacterial population. There was a similar variation trend between the activity of soil dehydrogenase, a microbial endoenzyme catalyzing the dehydrogenation of organic matter, and the soil microbes, which further demonstrated that the variations of soil microbes and their biochemical characteristics were the ecological mechanisms affecting the pyrene degradation in the pyrene-contaminated soil when the ryegrass root exudates dose increased. PMID:22263480

  18. Optimal inductive and cultural conditions of Polygonum multiflorum transgenic hairy roots mediated with Agrobacterium rhizogenes R1601 and an analysis of their anthraquinone constituents

    PubMed Central

    Huang, Bing; Lin, Huanjie; Yan, Chuanyan; Qiu, Hongyan; Qiu, Lipeng; Yu, Rongmin

    2014-01-01

    Background: Polygonum multiflorum is an important medicinal plant. Hairy roots systems obtained by transforming plant tissues with the natural genetic engineer Agrobacterium rhizogenes can produce valuable biological active substances, which have immense potential in the pharmaceutical industry. Objective: To optimize the inductive and cultural conditions of P. multiflorum hairy roots and to identify the major active secondary metabolites in hairy roots. Materials and Methods: P. multiflorum hairy root were mediated with A. rhizogenes R1601 to induce hairy roots. Four combinations, including Murashige–Skoog (MS), 1/2 MS, B5, and White, were investigated to optimize the culture medium. MS medium was selected for the growth measurement. The qualitative and quantitative determinations of free anthraquinone in hairy roots were compared with the calli and aseptic plantlets using high-performance liquid chromatography. Results: The inductive rates of hairy roots by leaves were higher than for any other explants. The presence of agropine in the P. multiflorum hairy roots confirmed that they were indeed transgenic. MS medium was the most suitable of the four media for hairy root growth. Meanwhile, the growth kinetics and nutrient consumption results showed that the hairy roots displayed a sigmoidal growth curve and that their optimal inoculation time was 18-21 days. The determination of the anthraquinone constituents indicated that the rhein content of the hairy roots reached 2.495 μg g−1 and was 2.55-fold higher than that of natural plants. Conclusion: Transgenic hairy roots of P. multiflorum could be one of the most potent materials for industrial-scale production of bioactive anthraquinone constituents. PMID:24696550

  19. Nuclear Factor Kappa B Activation and Peroxisome Proliferator-activated Receptor Transactivational Effects of Chemical Components of the Roots of Polygonum multiflorum

    PubMed Central

    Sun, Ya Nan; Li, Wei; Song, Seok Bean; Yan, Xi Tao; Yang, Seo Young; Kim, Young Ho

    2016-01-01

    Background: Polygonum multiflorum is well-known as “Heshouwu” in traditional Chinese herbal medicine. In Northeast Asia, it is often used as a tonic to prevent premature aging of the kidney and liver, tendons, and bones and strengthening of the lower back and knees. Objective: To research the anti-inflammatory activities of components from P. multiflorum. Materials and Methods: The compounds were isolated by a combination of silica gel and YMC R-18 column chromatography, and their structures were identified by analysis of spectroscopic data (1D, 2D-nuclear magnetic resonance, and mass spectrometry). The anti-inflammatory activities of the isolated compounds 1−15 were evaluated by luciferase reporter gene assays. Results: Fifteen compounds (1–15) were isolated from the roots of P. multiflorum. Compounds 1−5 and 14−15 significantly inhibited tumor necrosis factor-α-induced nuclear factor kappa B-luciferase activity, with IC50 values of 24.16-37.56 μM. Compounds 1−5 also greatly enhanced peroxisome proliferator-activated receptors transcriptional activity with EC50 values of 18.26−31.45 μM. Conclusion: The anthraquinone derivatives were the active components from the roots of P. multiflorum as an inhibitor on inflammation-related factors in human hepatoma cells. Therefore, we suggest that the roots of P. multiflorum can be used to treat natural inflammatory diseases. SUMMARY This study presented that fifteen compounds (1-15) isolated from the roots of Polygonum multiflrum exert signifiant anti inflmmatory effects by inhibiting TNF α induced NF κB activation and PPARs transcription. Abbreviation used: NF κB: Nuclear factor kappa B, PPARs: Peroxisome proliferator activated receptors, PPREs: Peroxisome proliferator response elements, TNF α: Tumor necrosis factor α, ESI-MS: Electrospray ionization mass spectrometry, HepG2: Human hepatoma cells PMID:27019559

  20. Mapping with RAD (restriction-site associated DNA) markers to rapidly identify QTL for stem rust resistance in Lolium perenne.

    PubMed

    Pfender, W F; Saha, M C; Johnson, E A; Slabaugh, M B

    2011-05-01

    A mapping population was created to detect quantitative trait loci (QTL) for resistance to stem rust caused by Puccinia graminis subsp. graminicola in Lolium perenne. A susceptible and a resistant plant were crossed to produce a pseudo-testcross population of 193 F(1) individuals. Markers were produced by the restriction-site associated DNA (RAD) process, which uses massively parallel and multiplexed sequencing of reduced-representation libraries. Additional simple sequence repeat (SSR) and sequence-tagged site (STS) markers were combined with the RAD markers to produce maps for the female (738 cM) and male (721 cM) parents. Stem rust phenotypes (number of pustules per plant) were determined in replicated greenhouse trials by inoculation with a field-collected, genetically heterogeneous population of urediniospores. The F(1) progeny displayed continuous distribution of phenotypes and transgressive segregation. We detected three resistance QTL. The most prominent QTL (qLpPg1) is located near 41 cM on linkage group (LG) 7 with a 2-LOD interval of 8 cM, and accounts for 30-38% of the stem rust phenotypic variance. QTL were detected also on LG1 (qLpPg2) and LG6 (qLpPg3), each accounting for approximately 10% of phenotypic variance. Alleles of loci closely linked to these QTL originated from the resistant parent for qLpPg1 and from both parents for qLpPg2 and qLpPg3. Observed quantitative nature of the resistance may be due to partial-resistance effects against all pathogen genotypes, or qualitative effects completely preventing infection by only some genotypes in the genetically mixed inoculum. RAD markers facilitated rapid construction of new genetic maps in this outcrossing species and will enable development of sequence-based markers linked to stem rust resistance in L. perenne. PMID:21344184

  1. Gross chromosome rearrangements are occurring in an accession of the grass Lolium rigidum.

    PubMed

    Thomas, H M; Harper, J A; Morgan, W G

    2001-01-01

    Chromosome structure was analysed at mitosis in root tip meristems of eight genotypes of Lolium rigidum. FISH revealed changed positions in the rDNA sites indicating extensive chromosome rearrangements; indeed no two genotypes were the same. In one genotype, there were differences between cells within individual root tips. The changed positions of the rDNA sites appear to be reflections of chromosome translocations and this was confirmed by the presence of quadrivalents at metaphase I of meiosis. Possible mechanisms are discussed for this exceptional level of chromosome instability. PMID:11721955

  2. Effect of pulp mill sludge on soil characteristics, microbial community and vegetal production of Lolium Perenne.

    PubMed

    Gallardo, F; Cea, M; Tortella, G R; Diez, M C

    2012-03-01

    The effect of pulp mill sludge addition (10-30 Mg/ha) to soil derived from volcanic ash (Andisol) on soil characteristics, microbial community and Lolium perenne L. cv quartet. biomass production was evaluated in field assays. Soil without sludge was used as a control treatment. The sludge addition improved the chemical properties of the soil. Organic matter and phosphorous content increased in the soil with increasing amounts of sludge, obtaining 35% more organic matter content with the application of 30 Mg/ha than the control soil. The phosphorous was accumulated into the soil after the end of cultivation improving the phosphorous pool in the soil. When 30 Mg/ha sludge was added to the soil, a biomass of Lolium perenne, was 60% more than the control soil at the end of the experiment. The analysis of soil microbial community showed that the application of sludge did not modify greatly the microbial community of fungi and bacteria even when high doses were applied. PMID:21193264

  3. Molecular characterisation and genetic mapping of candidate genes for qualitative disease resistance in perennial ryegrass (Lolium perenne L.)

    PubMed Central

    Dracatos, Peter M; Cogan, Noel OI; Sawbridge, Timothy I; Gendall, Anthony R; Smith, Kevin F; Spangenberg, German C; Forster, John W

    2009-01-01

    Background Qualitative pathogen resistance in both dicotyledenous and monocotyledonous plants has been attributed to the action of resistance (R) genes, including those encoding nucleotide binding site – leucine rich repeat (NBS-LRR) proteins and receptor-like kinase enzymes. This study describes the large-scale isolation and characterisation of candidate R genes from perennial ryegrass. The analysis was based on the availability of an expressed sequence tag (EST) resource and a functionally-integrated bioinformatics database. Results Amplification of R gene sequences was performed using template EST data and information from orthologous candidate using a degenerate consensus PCR approach. A total of 102 unique partial R genes were cloned, sequenced and functionally annotated. Analysis of motif structure and R gene phylogeny demonstrated that Lolium R genes cluster with putative ortholoci, and evolved from common ancestral origins. Single nucleotide polymorphisms (SNPs) predicted through resequencing of amplicons from the parental genotypes of a genetic mapping family were validated, and 26 distinct R gene loci were assigned to multiple genetic maps. Clusters of largely non-related NBS-LRR genes were located at multiple distinct genomic locations and were commonly found in close proximity to previously mapped defence response (DR) genes. A comparative genomics analysis revealed the co-location of several candidate R genes with disease resistance quantitative trait loci (QTLs). Conclusion This study is the most comprehensive analysis to date of qualitative disease resistance candidate genes in perennial ryegrass. SNPs identified within candidate genes provide a valuable resource for mapping in various ryegrass pair cross-derived populations and further germplasm analysis using association genetics. In parallel with the use of specific pathogen virulence races, such resources provide the means to identify gene-for-gene mechanisms for multiple host pathogen

  4. Plant vigour at establishment and following defoliation are both associated with responses to drought in perennial ryegrass (Lolium perenne L.)

    PubMed Central

    Hatier, Jean-Hugues B.; Faville, Marty J.; Hickey, Michael J.; Koolaard, John P.; Schmidt, Jana; Carey, Brandi-Lee; Jones, Chris S.

    2014-01-01

    Periodic drought events present a significant and, with climate change, increasing constraint on temperate forage plants’ production. Consequently, improving plants’ adaptive response to abiotic stress is a key goal to ensure agricultural productivity in these regions. In this study we developed a new methodology, using both area-based comparison and soil water content measurements of individual non-irrigated and irrigated clones, to assess performance of perennial ryegrass (Lolium perenne L.) genotypes subjected to moisture stress in a simulated competitive environment. We applied this method to the evaluation of a full-sibling population from a pair cross between genotypes from a New Zealand cultivar and a Moroccan ecotype. Our hypothesis was that: (i) both leaf lamina regrowth after defoliation (LR) and plant vigour affect plant performance during drought and rehydration; and (ii) quantitative trait loci (QTLs) associated with plant performance under moisture stress could be identified. Differences amongst genotypes in dry matter (DM) production, early vigour at establishment, leaf elongation rate and LR were measured. LR explained most of the variation in DM production during exposure to moisture deficit and rehydration followed by plant vigour, indicated by initial DM production in both treatments and subsequent measures of DM production of irrigated clones. We identified two main QTL regions associated with DM production and LR, both during drought exposure and rehydration. Further research focused on these regions should improve our understanding of the genetic control of drought response in this forage crop and potentially other grass species with significant synteny, and support improvement in performance through molecular breeding approaches. PMID:25104762

  5. Population.

    ERIC Educational Resources Information Center

    King, Pat; Landahl, John

    This pamphlet has been prepared in response to a new problem, a rapidly increasing population, and a new need, population education. It is designed to help teachers provide their students with some basic population concepts with stress placed on the elements of decision making. In the first section of the pamphlet, some of the basic concepts of…

  6. A Bioactivity-Based Method for Screening, Identification of Lipase Inhibitors, and Clarifying the Effects of Processing Time on Lipase Inhibitory Activity of Polygonum Multiflorum.

    PubMed

    Chang, Yan-Xu; Ge, Ai-Hua; Jiang, Yan; Teye Azietaku, John; Li, Jin; Gao, Xiu-Mei

    2016-01-01

    Traditional Chinese medicine (TCM) has been used for the treatment of many complex diseases. However, the bioactive components are always undefined. In this study, a bioactivity-based method was developed and validated to screen lipase inhibitors and evaluate the effects of processing on the lipase inhibitory activity of TCM by ultrahigh performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry and fraction collector (UHPLC/Q-TOF-MS-FC). The results showed that both Polygonum multiflorum and processed P. multiflorum extracts had inhibitory effect against lipase with IC50 values of 38.84 μg/mL and 190.6 μg/mL, respectively. Stilbenes, phenolic acid, flavonoids, and anthraquinones were considered to be the potential lipase inhibitors. Eleven potential lipase inhibitors were simultaneously determined by UHPLC. Principal component analysis (PCA) was employed in exploring the effects of processing time on lipase inhibitory activity of P. multiflorum. Compared with conventional methods, a bioactivity-based method could quantitatively analyze lipase inhibitory activity of individual constituent and provide the total lipase inhibitory activity of the samples. The results demonstrated that the activity integrated UHPLC/Q-TOF-MS-FC method was an effective and powerful tool for screening and identifying lipase inhibitors from traditional Chinese medicines. PMID:26925151

  7. A Bioactivity-Based Method for Screening, Identification of Lipase Inhibitors, and Clarifying the Effects of Processing Time on Lipase Inhibitory Activity of Polygonum Multiflorum

    PubMed Central

    Chang, Yan-xu; Ge, Ai-hua; Jiang, Yan; Teye Azietaku, John; Li, Jin; Gao, Xiu-mei

    2016-01-01

    Traditional Chinese medicine (TCM) has been used for the treatment of many complex diseases. However, the bioactive components are always undefined. In this study, a bioactivity-based method was developed and validated to screen lipase inhibitors and evaluate the effects of processing on the lipase inhibitory activity of TCM by ultrahigh performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry and fraction collector (UHPLC/Q-TOF-MS-FC). The results showed that both Polygonum multiflorum and processed P. multiflorum extracts had inhibitory effect against lipase with IC50 values of 38.84 μg/mL and 190.6 μg/mL, respectively. Stilbenes, phenolic acid, flavonoids, and anthraquinones were considered to be the potential lipase inhibitors. Eleven potential lipase inhibitors were simultaneously determined by UHPLC. Principal component analysis (PCA) was employed in exploring the effects of processing time on lipase inhibitory activity of P. multiflorum. Compared with conventional methods, a bioactivity-based method could quantitatively analyze lipase inhibitory activity of individual constituent and provide the total lipase inhibitory activity of the samples. The results demonstrated that the activity integrated UHPLC/Q-TOF-MS-FC method was an effective and powerful tool for screening and identifying lipase inhibitors from traditional Chinese medicines. PMID:26925151

  8. EFFICIENCY OF INDIRECT SELECTION FOR DRY MATTER YIELD BASED ON FRESH MATTER YIELD IN LOLIUM PERENNE L. SWARD PLOTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forage dry matter yield (DMY) is a high-priority trait in breeding perennial ryegrass (Lolium perenne L.). However, determining dry matter concentration is highly labor intensive. Indirect selection based on fresh matter yield (FMY) would be easier, quicker and less expensive and, for a similar leve...

  9. Cloning and characterization of a salt stress-inducible small GTPase gene from the model grass species Lolium temulentum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A gene encoding a small GTP binding protein (smGTP) related to the Rab2 gene family of GTPases was identified during the analysis of a salt stress suppression subtractive hybridization (SSH) expression library from the model grass species Lolium temulentum L. (Darnel ryegrass). The smGTP gene was fo...

  10. Progress towards elucidating the mechanisms of self-incompatibility in the grasses: further insights from studies in Lolium

    PubMed Central

    Klaas, Manfred; Yang, Bicheng; Bosch, Maurice; Thorogood, Daniel; Manzanares, Chloe; Armstead, Ian P.; Franklin, F. C. H.; Barth, Susanne

    2011-01-01

    Background and Scope Self-incompatibility (SI) in flowering plants ensures the maintenance of genetic diversity by ensuring outbreeding. Different genetic and mechanistic systems of SI among flowering plants suggest either multiple origins of SI or considerable evolutionary diversification. In the grasses, SI is based on two loci, S and Z, which are both polyallelic: an incompatible reaction occurs only if both S and Z alleles are matched in individual pollen with alleles of the pistil on which they alight. Such incompatibility is referred to as gametophytic SI (GSI). The mechanics of grass GSI is poorly understood relative to the well-characterized S-RNase-based single-locus GSI systems (Solanaceae, Rosaceae, Plantaginaceae), or the Papaver recognition system that triggers a calcium-dependent signalling network culminating in programmed cell death. There is every reason to suggest that the grass SI system represents yet another mechanism of SI. S and Z loci have been mapped using isozymes to linkage groups C1 and C2 of the Triticeae consensus maps in Secale, Phalaris and Lolium. Recently, in Lolium perenne, in order to finely map and identify S and Z, more closely spaced markers have been developed based on cDNA and repeat DNA sequences, in part from genomic regions syntenic between the grasses. Several genes tightly linked to the S and Z loci were identified, but so far no convincing candidate has emerged. Research and Progress From subtracted Lolium immature stigma cDNA libraries derived from S and Z genotyped individuals enriched for SI potential component genes, kinase enzyme domains, a calmodulin-dependent kinase and a peptide with several calcium (Ca2+) binding domains were identified. Preliminary findings suggest that Ca2+ signalling and phosphorylation may be involved in Lolium GSI. This is supported by the inhibition of Lolium SI by Ca2+ channel blockers lanthanum (La3+) and verapamil, and by findings of increased phosphorylation activity during an SI

  11. Feasibility of incorporating waste grass clippings (Lolium perenne L.) in particleboard composites.

    PubMed

    Nemli, Gökay; Demirel, Samet; Gümüşkaya, Esat; Aslan, Mustafa; Acar, Cengiz

    2009-03-01

    This study investigated some of the important physical (thickness swelling) and mechanical (modulus of rupture, modulus of elasticity and internal bond) properties of single-layer particleboard panels made from eucalyptus (Eucalyptus camaldulensis Dehn.), waste of grass clippings (Lolium perenne L.) and combinations of the two. The chemical properties (pH, holocelluse and alpha cellulose contents, and water, alcohol-benzene and 1% sodium hydroxide solubilities) of the raw materials were also determined. Panels with a 6:94 ratio of grass-to-eucalyptus particles had the required mechanical properties for interior fitments including furniture and general uses. Boards manufactured with 100% grass clippings exhibited the lowest quality. The overall panel properties improved with a lower percentage of grass clippings added. Based on initial results, it also appears that grass should compose no more than 13% to achieve acceptable panel properties for interior fitments and general uses. PMID:18804991

  12. Pollen Expression of Herbicide Target Site Resistance Genes in Annual Ryegrass (Lolium rigidum).

    PubMed Central

    Richter, J.; Powles, S. B.

    1993-01-01

    Herbicide resistance can occur either through target-site insensitivity or by nontarget site-based mechanisms. Two herbicide-resistant biotypes of Lolium rigidum Gaud., one resistant to acetolactate synthase (ALS)-inhibiting herbicides (biotype WLR1) and the other resistant to acetyl CoA carboxylase (ACCase)-inhibiting herbicides (biotype WLR96) through target-site insensitivity at the whole plant and enzymic levels, were found to express this resistance in the pollen. Pollen produced by resistant biotypes grew uninhibited when challenged with herbicide, whereas that from a susceptible biotype was inhibited. A third biotype, SLR31, resistant to ACCase-inhibiting and certain ALS-inhibiting herbicides at the whole plant level through nontarget site-based mechanisms, did not exhibit this expression in the pollen. The technique described may form the basis for a rapid screen for certain nuclear-encoded, target site-based herbicide-resistance mechanisms. PMID:12231886

  13. Application of Ultra-High-Performance Liquid Chromatography Coupled with LTQ-Orbitrap Mass Spectrometry for the Qualitative and Quantitative Analysis of Polygonum multiflorum Thumb. and Its Processed Products.

    PubMed

    Wang, Teng-Hua; Zhang, Jing; Qiu, Xiao-Hui; Bai, Jun-Qi; Gao, You-Heng; Xu, Wen

    2015-01-01

    In order to quickly and simultaneously obtain the chemical profiles and control the quality of the root of Polygonum multiflorum Thumb. and its processed form, a rapid qualitative and quantitative method, using ultra-high-performance liquid chromatography coupled with electrospray ionization-linear ion trap-Orbitrap hybrid mass spectrometry (UHPLC-LTQ-Orbitrap MS(n)) has been developed. The analysis was performed within 10 min on an AcQuity UPLC™ BEH C18 column with a gradient elution of 0.1% formic acid-acetonitrile at flow rate of 400 μL/min. According to the fragmentation mechanism and high resolution MS(n) data, a diagnostic ion searching strategy was used for rapid and tentative identification of main phenolic components and 23 compounds were simultaneously identified or tentatively characterized. The difference in chemical profiles between P. multiflorum and its processed preparation were observed by comparing the ions abundances of main constituents in the MS spectra and significant changes of eight metabolite biomarkers were detected in the P. multiflorum samples and their preparations. In addition, four of the representative phenols, namely gallic acid, trans-2,3,5,4'-tetra-hydroxystilbene-2-O-β-d-glucopyranoside, emodin and emodin-8-O-β-d-glucopyranoside were quantified by the validated UHPLC-MS/MS method. These phenols are considered to be major bioactive constituents in P. multiflorum, and are generally regarded as the index for quality assessment of this herb. The method was successfully used to quantify 10 batches of P. multiflorum and 10 batches of processed P. multiflorum. The results demonstrated that the method is simple, rapid, and suitable for the discrimination and quality control of this traditional Chinese herb. PMID:26712736

  14. Selection for low or high primary dormancy in Lolium rigidum Gaud seeds results in constitutive differences in stress protein expression and peroxidase activity

    PubMed Central

    Goggin, Danica E.; Powles, Stephen B.; Steadman, Kathryn J.

    2011-01-01

    Seed dormancy in wild Lolium rigidum Gaud (annual ryegrass) populations is highly variable and not well characterized at the biochemical level. To identify some of the determinants of dormancy level in these seeds, the proteomes of subpopulations selected for low and high levels of primary dormancy were compared by two-dimensional polyacrylamide gel electrophoresis of extracts from mature, dry seeds. High-dormancy seeds showed higher expression of small heat shock proteins, enolase, and glyoxalase I than the low-dormancy seeds. The functional relevance of these differences in protein expression was confirmed by the fact that high-dormancy seeds were more tolerant to high temperatures imposed at imbibition and had consistently higher glyoxalase I activity over 0–42 d dark stratification. Higher expression of a putative glutathione peroxidase in low-dormancy seeds was not accompanied by higher activity, but these seeds had a slightly more oxidized glutathione pool and higher total peroxidase activity. Overall, these biochemical and physiological differences suggest that L. rigidum seeds selected for low dormancy are more prepared for rapid germination via peroxidase-mediated cell wall weakening, whilst seeds selected for high dormancy are constitutively prepared to survive environmental stresses, even in the absence of stress during seed development. PMID:20974739

  15. Amendments promote the development of Lolium perenne in soils affected by historical copper smelting operations.

    PubMed

    Goecke, Paul; Ginocchio, Rosanna; Mench, Michel; Neaman, Alexander

    2011-07-01

    The Puchuncaví valley, central Chile, has been exposed to aerial emissions from a copper smelter. Nowadays, soils in the surroundings are sparsely-vegetated, acidic, and metal-contaminated, and their remediation is needed to reduce environmental risks. We assessed effectiveness of lime, fly ash, compost, and iron grit as amendments to immobilize Cu in soils and promote plant growth. Amended soils were cultivated with Lolium perenne for 60 days under controlled conditions. Total dissolved Cu and Cu2+ activity in the soil solution, ryegrass biomass, and Cu accumulation in plant tissues were measured. Addition of lime and fly ash decreased Cu concentrations and Cu2+ activity in the soil solution, increased plant biomass, and reduced shoot Cu concentration below 22 mg kg(-1) (the phytotoxicity threshold for the species). The most effective amendment with respect to the shoot biomass yield was a combination of lime and compost. Water content of the substrate and the K accumulation were positively correlated with the compost application rate. Compost combined with iron grit decreased dissolved Cu concentrations during the period of highest solubility, i.e., during the first 60 days after the compost application. However, iron grit incorporation into soils amended with lime and compost decreased the shoot biomass of ryegrass. PMID:21972502

  16. Dissecting the regulation of fructan metabolism in perennial ryegrass (Lolium perenne) with quantitative trait locus mapping.

    PubMed

    Turner, L B; Cairns, A J; Armstead, I P; Ashton, J; Skøt, K; Whittaker, D; Humphreys, M O

    2006-01-01

    Quantitative trait locus (QTL) mapping, which can be a useful tool for dissecting complex traits, has been used here to study the regulation of fructan metabolism in temperate forage grasses. An F2 mapping family, derived from a high water-soluble carbohydrate (WSC) x low WSC cross, was used to map fructans and the other components of WSC (sucrose, glucose and fructose) in leaves and tiller bases of perennial ryegrass (Lolium perenne) in spring and autumn. To characterize regions of the genome that control basic carbohydrate metabolism, a strategy to minimize the impact of genotype (G) x environment (E), and E-effects on the characterization of G-effects, was adopted. Most traits were highly variable within the family. There was also considerable year-to-year environmental variation. However, significant genetic effects were detected, and several traits had high broad-sense heritability. QTL were identified on chromosomes 1, 2, 5 and 6. Leaf and tiller base QTL did not coincide. Individual QTL explained between 8 and 59% of the total phenotypic variation in the traits. Fructan turnover, metabolism and their genetic control, and the effect of environment, are discussed in the context of the results. PMID:16390418

  17. A synteny-based draft genome sequence of the forage grass Lolium perenne.

    PubMed

    Byrne, Stephen L; Nagy, Istvan; Pfeifer, Matthias; Armstead, Ian; Swain, Suresh; Studer, Bruno; Mayer, Klaus; Campbell, Jacqueline D; Czaban, Adrian; Hentrup, Stephan; Panitz, Frank; Bendixen, Christian; Hedegaard, Jakob; Caccamo, Mario; Asp, Torben

    2015-11-01

    Here we report the draft genome sequence of perennial ryegrass (Lolium perenne), an economically important forage and turf grass species that is widely cultivated in temperate regions worldwide. It is classified along with wheat, barley, oats and Brachypodium distachyon in the Pooideae sub-family of the grass family (Poaceae). Transcriptome data was used to identify 28 455 gene models, and we utilized macro-co-linearity between perennial ryegrass and barley, and synteny within the grass family, to establish a synteny-based linear gene order. The gametophytic self-incompatibility mechanism enables the pistil of a plant to reject self-pollen and therefore promote out-crossing. We have used the sequence assembly to characterize transcriptional changes in the stigma during pollination with both compatible and incompatible pollen. Characterization of the pollen transcriptome identified homologs to pollen allergens from a range of species, many of which were expressed to very high levels in mature pollen grains, and are potentially involved in the self-incompatibility mechanism. The genome sequence provides a valuable resource for future breeding efforts based on genomic prediction, and will accelerate the development of new varieties for more productive grasslands. PMID:26408275

  18. Plant uptake and phytotoxicity of decabromodiphenyl ether (BDE-209) in ryegrass (Lolium perenne L).

    PubMed

    Xie, Xianchuan; Qian, Yan; Xue, Yingang; He, Huan; Wei, Dongyang

    2013-10-01

    The plant uptake and phytotoxicity of decabromodiphenyl ether (BDE-209) in ryegrass (Lolium perenne L) seedlings were investigated. Results showed that ryegrass could take up BDE-209 from the contaminated soils and most of the BDE-209 in plants is located in roots, indicating that BDE-209 has low root-to-shoot translocation. Except for about 35% inhibition of root growth and about 30% decrease of the chlorophyll b and carotenoid contents of leaves, no visual toxicity symptoms were observed in seedlings grown even at a high concentration of 100 mg kg(-1). BDE-209 exposure significantly induced the generation of the superoxide radical (O2˙(-)) and malondialdehyde (MDA) in ryegrass leaves. With the increase of BDE-209 concentration, the activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), and glutathione-S-transferase (GST) were significantly changed, and the ratio of reduced glutathione to oxidized glutathione (GSH/GSSG) was also significantly reduced. Results suggested that BDE-209 exposure could cause oxidative stress and damage, which may play an important role in the phytotoxicity of BDE-209 in ryegrass seedlings. PMID:23999790

  19. Lolium perenne grasslands may function as a sink for atmospheric carbon dioxide

    SciTech Connect

    Ginkel, J.H. van; Whitmore, A.P.; Gorissen, A.

    1999-10-01

    Model calculations and scenario studies suggest the existence of a considerable positive feedback between temperature and CO{sub 2} levels in the atmosphere. Rising temperatures are supposed to increase decomposition of soil organic C leading to increased production of CO{sub 2} and this extra CO{sub 2} induces a positive feedback by raising the temperature still further. Evidence was found that negative feedback mechanisms also exist; more primary production is allocated to roots as atmospheric CO{sub 2} rises and these roots decompose more slowly than roots grown at ambient CO{sub 2} levels. Experimental data partly obtained with {sup 14}C-techniques were applied in a grassland C model. The model results show that at an atmospheric CO{sub 2} concentration of 700 {micro}L L{sup {minus}1} increased below ground C storage will be more than sufficient to balance the increased decomposition of soil organic C in a ryegrass (Lolium perenne L.) grassland soil. Once a doubling of the present atmospheric CO{sub 2} concentration has been reached, C equivalent to 55% of the annual CO{sub 2} increase above 1 ha ryegrass can be withdrawn from the atmosphere. This indicates that grassland soils represent a significant sink for rising atmospheric CO{sub 2}.

  20. Toxicity and uptake of cyclic nitramine explosives in ryegrass Lolium perenne.

    PubMed

    Rocheleau, Sylvie; Lachance, Bernard; Kuperman, Roman G; Hawari, Jalal; Thiboutot, Sonia; Ampleman, Guy; Sunahara, Geoffrey I

    2008-11-01

    Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), and 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) are cyclic nitramines used as explosives. Their ecotoxicities have been characterized incompletely and little is known about their accumulation potential in soil organisms. We assessed the toxicity and uptake of these explosives in perennial ryegrass Lolium perenne L. exposed in a Sassafras sandy loam (SSL) or in a sandy soil (DRDC, CL-20 only) containing contrasting clay contents (11% and 0.3%, respectively). A 21-d exposure to RDX, HMX or CL-20 in either soil had no adverse effects on ryegrass growth. RDX and HMX were translocated to ryegrass shoots, with bioconcentration factors (BCF) of up to 15 and 11, respectively. In contrast, CL-20 was taken up by the roots (BCF up to 19) with no translocation to the shoots. These studies showed that RDX, HMX, and CL-20 can accumulate in plants and may potentially pose a risk of biomagnification across the food chain. PMID:18358578

  1. Isolation of N2 -fixing rhizobacteria from Lolium perenne and evaluating their plant growth promoting traits.

    PubMed

    Castellano-Hinojosa, Antonio; Correa-Galeote, David; Palau, Josep; Bedmar, Eulogio J

    2016-01-01

    Twenty one dinitrogen (N2 )-fixing bacteria were isolated from the rhizosphere of Lolium perenne grown for more than 10 years without N-fertilization. The nearly complete sequence of the 16S rRNA gene of each strain and pairwise alignments among globally aligned sequences of the 16S rRNA genes clustered them into nine different groups. Out of the 21 strains, 11 were members of genus Bacillus, 3 belonged to each one of genera Paenibacillus and Pseudoxanthomonas, and the remaining 2 strains to each one of genera Burkholderia and Staphylococcus, respectively. A representative strain from each group contained the nifH gene and fixed atmospheric N2 as determined by the acetylene-dependent ethylene production assay (acetylene reduction activity, ARA). The nine selected strains were also examined to behave as plant growth promoting bacteria (PGPRs) including their ability to act as a biocontrol agent. The nine representative strains produced indol acetic acid (IAA) and solubilized calcium triphosphate, five of them, strains C2, C3, C12, C15, and C16, had ACC deaminase activity, and strains C2, C3, C4, C12, C16, and C17 produced siderophores. Strains C13, C16, and C17 had the capability to control growth of the pathogen Fusarium oxysporum mycelial growth in vitro. PCA analysis of determined PGPR properties showed that ARA, ACC deaminase activity, and siderophore production were the most valuable as they had the maximal contribution to the total variance. PMID:26781208

  2. Gene expression analysis of perennial ryegrass (Lolium perenne) using cDNA microarrays

    NASA Astrophysics Data System (ADS)

    Ong, Eng-Kok; Sawbridge, Tim; Webster, Tracie; Emmerling, Michael; Nguyen, Nga; Nunan, Katrina; O'Neill, Matthew; O'Toole, Fiona; Rhodes, Carolyn; Simmonds, Jason; Tian, Pei; Wearne, Katherine; Winkworth, Amanda; Spangenberg, German

    2003-07-01

    Perennial ryegrass (Lolium perenne) is a major forage grass of temperate pastures. A genomics program has been undertaken generating over 52,000 expressed sequence tags (ESTs). Cluster analysis of the ESTs identified approximately 14,600 ryegrass unigenes. In this report, we described the application of ryegrass unigene cDNAs to produce ryegrass 15K microarray. Fifteen microarray hybridisations were performed with labeled total RNA isolated from a variety of plant organs and developmental stages. In a proof of concept, gene expression profiling of ryegrass ESTs using the 15K unigene microarrays has been established using several known genes and two cluster analysis approaches (parallel coordinate planes plot and hierarchical clustering). The expression profile of the known genes (e.g. rubisco and invertase) corresponds well with published data. The microarray expression profile of a ryegrass putative root specific kinase gene was also verified with Northern blotting. This combination of DNA microarray hybridisations and cluster analysis can be applied as a tool for the identification of novel sequences of unknown function.

  3. Activation of sucrose transport in defoliated Lolium perenne L.: an example of apoplastic phloem loading plasticity.

    PubMed

    Berthier, Alexandre; Desclos, Marie; Amiard, Véronique; Morvan-Bertrand, Annette; Demmig-Adams, Barbara; Adams, William W; Turgeon, Robert; Prud'homme, Marie-Pascale; Noiraud-Romy, Nathalie

    2009-07-01

    The pathway of carbon phloem loading was examined in leaf tissues of the forage grass Lolium perenne. The effect of defoliation (leaf blade removal) on sucrose transport capacity was assessed in leaf sheaths as the major carbon source for regrowth. The pathway of carbon transport was assessed via a combination of electron microscopy, plasmolysis experiments and plasma membrane vesicles (PMVs) purified by aqueous two-phase partitioning from the microsomal fraction. Results support an apoplastic phloem loading mechanism. Imposition of an artificial proton-motive force to PMVs from leaf sheaths energized an active, transient and saturable uptake of sucrose (Suc). The affinity of Suc carriers for Suc was 580 microM in leaf sheaths of undefoliated plants. Defoliation induced a decrease of K(m) followed by an increase of V(max). A transporter was isolated from stubble (including leaf sheaths) cDNA libraries and functionally expressed in yeast. The level of L.perenne SUcrose Transporter 1 (LpSUT1) expression increased in leaf sheaths in response to defoliation. Taken together, the results indicate that Suc transport capacity increased in leaf sheaths of L. perenne in response to leaf blade removal. This increase might imply de novo synthesis of Suc transporters, including LpSUT1, and may represent one of the mechanisms contributing to rapid refoliation. PMID:19520670

  4. Ecological assessment of soil using a soil elutriate and the perennial ryegrass, Lolium perenne

    SciTech Connect

    Lawrence, C.; Meyers-Shone, L.; Duh, D.

    1995-12-31

    A 28-day plant bioassay using the perennial ryegrass, Lolium perenne, was utilized for an ecological assessment of soil from a hazardous waste site. An elutriate of the test soil was prepared and nutrients added, so that the seedlings would have direct exposure via uptake and to control for poor plant growth due to a lack of nutrients or proper soil profile characteristics. Use of an elutriate as the exposure medium assumes that those contaminants that can become waterborne for uptake by plants in the site conditions is the same as those which can be separated from adsorption to soil particulates during elutriate preparation. The ryegrass seeds were planted in a hydroponic system consisting of an upper chamber with an inert soil for a growth matrix and a lower reservoir with the nutrient and soil elutriate. Polyester cords were used to continuously wick the solution up to the inert soil and the chambers were drenched twice daily with the solution in the reservoir. At the conclusion of the study the plants` shoot length and dry weight (biomass) were measured to assess phytotoxicity of constituents in soil. The results of the test plants parameters were statistically compared to control plants to determine if test soil elutriates caused a measurable effect on ryegrass, The results of this plant bioassay provided additional and useful information for assessment of test soil.

  5. Allergen Microarray Indicates Pooideae Sensitization in Brazilian Grass Pollen Allergic Patients

    PubMed Central

    Moreira, Priscila Ferreira de Sousa; Gangl, Katharina; Vieira, Francisco de Assis Machado; Ynoue, Leandro Hideki; Linhart, Birgit; Flicker, Sabine; Fiebig, Helmut; Swoboda, Ines; Focke-Tejkl, Margarete; Taketomi, Ernesto Akio; Valenta, Rudolf; Niederberger, Verena

    2015-01-01

    Background Grass pollen, in particular from Lolium multiflorum is a major allergen source in temperate climate zones of Southern Brazil. The IgE sensitization profile of Brazilian grass pollen allergic patients to individual allergen molecules has not been analyzed yet. Objective To analyze the IgE sensitization profile of a Brazilian grass pollen allergic population using individual allergen molecules. Methods We analyzed sera from 78 grass pollen allergic patients for the presence of IgE antibodies specific for 103 purified micro-arrayed natural and recombinant allergens by chip technology. IgE-ELISA inhibition experiments with Lolium multiflorum, Phleum pratense extracts and a recombinant fusion protein consisting of Phl p 1, Phl p 2, Phl p 5 and Phl p 6 were performed to investigate cross-reactivities. Results Within the Brazilian grass pollen allergic patients, the most frequently recognized allergens were Phl p 1 (95%), Phl p 5 (82%), Phl p 2 (76%) followed by Phl p 4 (64%), Phl p 6 (45%), Phl p 11 (18%) and Phl p 12 (18%). Most patients were sensitized only to grass pollen allergens but not to allergens from other sources. A high degree of IgE cross-reactivity between Phleum pratense, Lolium multiflorum and the recombinant timothy grass fusion protein was found. Conclusions Component-resolved analysis of sera from Brazilian grass pollen allergic patients reveals an IgE recognition profile compatible with a typical Pooideae sensitization. The high degree of cross-reactivity between Phleum pratense and Lolium multiflorum allergens suggests that diagnosis and immunotherapy can be achieved with timothy grass pollen allergens in the studied population. PMID:26067084

  6. Effects of mesotrione on perennial ryegrass (Lolium perenne L.) carotenoid concentrations under varying environmental conditions.

    PubMed

    McCurdy, James D; McElroy, J Scott; Kopsell, Dean A; Sams, Carl E; Sorochan, John C

    2008-10-01

    Mesotrione is a carotenoid biosynthesis inhibiting herbicide, which is being evaluated for use in turfgrass. Carotenoids are important light harvesting and photoprotecting pigments that dissipate and quench excess light energy. The effects of mesotrione on carotenoid concentrations in turf and weed species, such as perennial ryegrass (Lolium perenne L.), are poorly understood. Mesotrione injury to perennial ryegrass has been reported, and symptomology may differ due to postapplication environmental factors such as irradiance and temperature. Research was conducted to investigate the effects of mesotrione on perennial ryegrass under varying irradiance (600, 1100, or 1600 micromol/m (2)/s) at three different temperatures (18, 26, and 34 degrees C). Postapplication irradiance and temperature levels did not affect visual injury symptoms in perennial ryegrass. Bleaching of treated plants was highest 7 days after treatment (DAT; 8%) and recovered to nontreated levels by 21 DAT. Mesotrione applications did not decrease perennial ryegrass foliar biomass accumulations. Carotenoid concentrations of nontreated plants were similar to those reported in creeping bentgrass and many green leafy vegetable crops. However, chlorophyll a and b, beta-carotene, lutein, and violaxanthin concentrations decreased due to mesotrione applications, while phytoene and zeaxanthin, a photoprotecting carotenoid, increased. The photochemical efficiency (F v/ F m) of treated plants was lower than nontreated plants at 3 and 7 DAT; however, treated plants recovered to nontreated levels 21 DAT. Results indicate that postapplication irradiance and temperature levels may not affect mesotrione efficacy in perennial ryegrass. Preferential accumulation of zeaxanthin following mesotrione applications may be a stress-related response, which may reduce light harvesting complex size and directly quench excess light energy. PMID:18788815

  7. Pollen-Mediated Movement of Herbicide Resistance Genes in Lolium rigidum

    PubMed Central

    Loureiro, Iñigo; Escorial, María-Concepción; Chueca, María-Cristina

    2016-01-01

    The transfer of herbicide resistance genes by pollen is a major concern in cross-pollinated species such as annual ryegrass (Lolium rigidum). A two-year study was conducted in the greenhouse, under favorable conditions for pollination, to generate information on potential maximum cross-pollination. This maximum cross-pollination rate was 56.1%. A three-year field trial was also conducted to study the cross-pollination rates in terms of distance and orientation to an herbicide-resistant pollen source. Under field conditions, cross-pollination rates varied from 5.5% to 11.6% in plants adjacent to the pollen source and decreased with increasing distances (1.5 to 8.9% at 15 m distance and up to 4.1% at 25 m in the downwind direction). Environmental conditions influenced the cross-pollination both under greenhouse and field conditions. Data were fit to an exponential decay model to predict gene flow at increasing distances. This model predicted an average gene flow of 7.1% when the pollen donor and recipient plants were at 0 m distance from each other. Pollen-mediated gene flow declined by 50% at 16.7 m from the pollen source, yet under downwind conditions gene flow of 5.2% was predicted at 25 m, the farthest distance studied. Knowledge of cross-pollination rates will be useful for assessing the spread of herbicide resistance genes in L. rigidum and in developing appropriate strategies for its mitigation. PMID:27336441

  8. Development of molecular markers, based on chloroplast and ribosomal DNA regions, to discriminate three popular medicinal plant species, Cynanchum wilfordii, Cynanchum auriculatum, and Polygonum multiflorum.

    PubMed

    Han, Eun-Heui; Cho, KyeMan; Goo, YoungMin; Kim, ManBae; Shin, Young-Wook; Kim, Yun-Hee; Lee, Shin-Woo

    2016-04-01

    Identification of plant species is important for standardizing herbal medicine. Cynanchum wilfordii (Baekshuoh in Korean) and Polygonum multiflorum (Hashuoh in Korean) are important oriental medicinal herbs in Korea, Japan, and China. Cynanchum auriculatum is a faster growing and more productive plant than C. wilfordii; and, it is not recognized as a medicinal plant in the Korean Pharmacopoeia. C. wilfordii, P. multiflorum, and C. auriculatum are often misidentified in the Korean herbal medicine marketplace due to their morphological similarities and similar names. In this study, we investigated molecular authentication of these three medicinal plants using DNA sequences in the TrnL-F chloroplast intergenic region. Specific species identification was achieved by detecting allelic variations of single nucleotide polymorphisms (SNPs) using amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) and high resolution melting curve analysis. Our results demonstrate that the intraspecific genetic distance between C. wilfordii and C. auriculatum is relatively low. We also developed a quantitative PCR assay using species-specific TrnL-F primers, which allowed us to estimate the ratio of C. wilfordii and C. auriculatum using varying ratios of mixed genomic DNA template from the two species. Additionally, to identify species in hybrid plants produced by cross-fertilization, we analyzed nuclear ribosomal DNA internal transcribed spacer regions in C. wilfordii and C. auriculatum by ARMS-PCR. Our results indicate that SNP-based molecular markers, usable to barcode tools could provide efficient and rapid authentication of these closely related medicinal plant species, and will be useful for preventing the distribution of products contaminated with adulterants. PMID:26902862

  9. Lambs Fed Fresh Winter Forage Rape (Brassica napus L.) Emit Less Methane than Those Fed Perennial Ryegrass (Lolium perenne L.), and Possible Mechanisms behind the Difference

    PubMed Central

    Sun, Xuezhao; Henderson, Gemma; Cox, Faith; Molano, German; Harrison, Scott J.; Luo, Dongwen; Janssen, Peter H.; Pacheco, David

    2015-01-01

    The objectives of this study were to examine long-term effects of feeding forage rape (Brassica napus L.) on methane yields (g methane per kg of feed dry matter intake), and to propose mechanisms that may be responsible for lower emissions from lambs fed forage rape compared to perennial ryegrass (Lolium perenne L.). The lambs were fed fresh winter forage rape or ryegrass as their sole diet for 15 weeks. Methane yields were measured using open circuit respiration chambers, and were 22-30% smaller from forage rape than from ryegrass (averages of 13.6 g versus 19.5 g after 7 weeks, and 17.8 g versus 22.9 g after 15 weeks). The difference therefore persisted consistently for at least 3 months. The smaller methane yields from forage rape were not related to nitrate or sulfate in the feed, which might act as alternative electron acceptors, or to the levels of the potential inhibitors glucosinolates and S-methyl L-cysteine sulfoxide. Ruminal microbial communities in forage rape-fed lambs were different from those in ryegrass-fed lambs, with greater proportions of potentially propionate-forming bacteria, and were consistent with less hydrogen and hence less methane being produced during fermentation. The molar proportions of ruminal acetate were smaller and those of propionate were greater in forage rape-fed lambs, consistent with the larger propionate-forming populations and less hydrogen production. Forage rape contained more readily fermentable carbohydrates and less structural carbohydrates than ryegrass, and was more rapidly degraded in the rumen, which might favour this fermentation profile. The ruminal pH was lower in forage rape-fed lambs, which might inhibit methanogenic activity, shifting the rumen fermentation to more propionate and less hydrogen and methane. The significance of these two mechanisms remains to be investigated. The results suggest that forage rape is a potential methane mitigation tool in pastoral-based sheep production systems. PMID:25803688

  10. Lambs fed fresh winter forage rape (Brassica napus L.) emit less methane than those fed perennial ryegrass (Lolium perenne L.), and possible mechanisms behind the difference.

    PubMed

    Sun, Xuezhao; Henderson, Gemma; Cox, Faith; Molano, German; Harrison, Scott J; Luo, Dongwen; Janssen, Peter H; Pacheco, David

    2015-01-01

    The objectives of this study were to examine long-term effects of feeding forage rape (Brassica napus L.) on methane yields (g methane per kg of feed dry matter intake), and to propose mechanisms that may be responsible for lower emissions from lambs fed forage rape compared to perennial ryegrass (Lolium perenne L.). The lambs were fed fresh winter forage rape or ryegrass as their sole diet for 15 weeks. Methane yields were measured using open circuit respiration chambers, and were 22-30% smaller from forage rape than from ryegrass (averages of 13.6 g versus 19.5 g after 7 weeks, and 17.8 g versus 22.9 g after 15 weeks). The difference therefore persisted consistently for at least 3 months. The smaller methane yields from forage rape were not related to nitrate or sulfate in the feed, which might act as alternative electron acceptors, or to the levels of the potential inhibitors glucosinolates and S-methyl L-cysteine sulfoxide. Ruminal microbial communities in forage rape-fed lambs were different from those in ryegrass-fed lambs, with greater proportions of potentially propionate-forming bacteria, and were consistent with less hydrogen and hence less methane being produced during fermentation. The molar proportions of ruminal acetate were smaller and those of propionate were greater in forage rape-fed lambs, consistent with the larger propionate-forming populations and less hydrogen production. Forage rape contained more readily fermentable carbohydrates and less structural carbohydrates than ryegrass, and was more rapidly degraded in the rumen, which might favour this fermentation profile. The ruminal pH was lower in forage rape-fed lambs, which might inhibit methanogenic activity, shifting the rumen fermentation to more propionate and less hydrogen and methane. The significance of these two mechanisms remains to be investigated. The results suggest that forage rape is a potential methane mitigation tool in pastoral-based sheep production systems. PMID:25803688

  11. Ergot alkaloid intoxication in perennial ryegrass (Lolium perenne): an emerging animal health concern in Ireland?

    PubMed

    Canty, Mary J; Fogarty, Ursula; Sheridan, Michael K; Ensley, Steve M; Schrunk, Dwayne E; More, Simon J

    2014-01-01

    Four primary mycotoxicosis have been reported in livestock caused by fungal infections of grasses or cereals by members of the Clavicipitaceae family. Ergotism (generally associated with grasses, rye, triticale and other grains) and fescue toxicosis (associated with tall fescue grass, Festuca arundinacea) are both caused by ergot alkaloids, and referred to as 'ergot alkaloid intoxication'. Ryegrass staggers (associated with perennial ryegrass Lolium perenne) is due to intoxication with an indole-diperpene, Lolitrem B, and metabolites. Fescue-associated oedema, recently described in Australia, may be associated with a pyrrolizidine alkaloid, N-acetyl norloline. Ergotism, caused by the fungus Claviceps purpurea, is visible and infects the outside of the plant seed. Fescue toxicosis and ryegrass staggers are caused by Neotyphodium coenophalium and N. lolii, respectively. Fescue-associated oedema has been associated with tall fescue varieties infected with a specific strain of N. coenophialum (AR542, Max P or Max Q). The name Neotyphodium refers to asexual derivatives of Epichloë spp., which have collectively been termed the epichloë fungi. These fungi exist symbiotically within the grass and are invisible to the naked eye. The primary toxicological effect of ergot alkaloid involves vasoconstriction and/or hypoprolactinaemia. Ingestion of ergot alkaloid by livestock can cause a range of effects, including poor weight gain, reduced fertility, hyperthermia, convulsions, gangrene of the extremities, and death. To date there are no published reports, either internationally or nationally, reporting ergot alkaloid intoxication specifically associated with perennial ryegrass endophytes. However, unpublished reports from the Irish Equine Centre have identified a potential emerging problem of ergot alkaloid intoxication with respect to equines and bovines, on primarily perennial ryegrass-based diets. Ergovaline has been isolated in varying concentrations in the herbage of a

  12. Ergot alkaloid intoxication in perennial ryegrass (Lolium perenne): an emerging animal health concern in Ireland?

    PubMed Central

    2014-01-01

    Four primary mycotoxicosis have been reported in livestock caused by fungal infections of grasses or cereals by members of the Clavicipitaceae family. Ergotism (generally associated with grasses, rye, triticale and other grains) and fescue toxicosis (associated with tall fescue grass, Festuca arundinacea) are both caused by ergot alkaloids, and referred to as ‘ergot alkaloid intoxication’. Ryegrass staggers (associated with perennial ryegrass Lolium perenne) is due to intoxication with an indole-diperpene, Lolitrem B, and metabolites. Fescue-associated oedema, recently described in Australia, may be associated with a pyrrolizidine alkaloid, N-acetyl norloline. Ergotism, caused by the fungus Claviceps purpurea, is visible and infects the outside of the plant seed. Fescue toxicosis and ryegrass staggers are caused by Neotyphodium coenophalium and N. lolii, respectively. Fescue-associated oedema has been associated with tall fescue varieties infected with a specific strain of N. coenophialum (AR542, Max P or Max Q). The name Neotyphodium refers to asexual derivatives of Epichloë spp., which have collectively been termed the epichloë fungi. These fungi exist symbiotically within the grass and are invisible to the naked eye. The primary toxicological effect of ergot alkaloid involves vasoconstriction and/or hypoprolactinaemia. Ingestion of ergot alkaloid by livestock can cause a range of effects, including poor weight gain, reduced fertility, hyperthermia, convulsions, gangrene of the extremities, and death. To date there are no published reports, either internationally or nationally, reporting ergot alkaloid intoxication specifically associated with perennial ryegrass endophytes. However, unpublished reports from the Irish Equine Centre have identified a potential emerging problem of ergot alkaloid intoxication with respect to equines and bovines, on primarily perennial ryegrass-based diets. Ergovaline has been isolated in varying concentrations in the herbage of

  13. Tilletia vankyi, a new species of reticulate-spored bunt fungus with non-conjugating basidiospores infecting species of Festuca and Lolium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A bunt fungus infecting commercial perennial ryegrass (Lolium perenne) from Australia and chewings fescue (Festuca rubra) from the U.S.A. exhibits a spore germination pattern that is unique from other reticulately-spored species of Tilletia infecting hosts in the grass subfamily Pooideae. Teliospor...

  14. Enhanced expression of Rubisco activase splicing variants differentially affects Rubisco activity during low temperature treatment in Lolium perenne.

    PubMed

    Jurczyk, Barbara; Pociecha, Ewa; Grzesiak, Maciej; Kalita, Katarzyna; Rapacz, Marcin

    2016-07-01

    Alternative splicing of the Rubisco activase gene was shown to be a point for optimization of photosynthetic carbon assimilation. It can be expected to be a stress-regulated event that depends on plant freezing tolerance. The aim of the study was to examine the relationships among Rubisco activity, the expression of two Rubisco activase splicing variants and photoacclimation to low temperature. The experiment was performed on two Lolium perenne genotypes with contrasting levels of freezing tolerance. The study investigated the effect of pre-hardening (15°C) and cold acclimation (4°C) on net photosynthesis, photosystem II photochemical activity, Rubisco activity and the expression of two splicing variants of the Rubisco activase gene. The results showed an induction of Rubisco activity at both 15°C and 4°C only in a highly freezing-tolerant genotype. The enhanced Rubisco activity after pre-hardening corresponded to increased expression of the splicing variant representing the large isoform, while the increase in Rubisco activity during cold acclimation was due to the activation of both transcript variants. These boosts in Rubisco activity also corresponded to an activation of non-photochemical mechanism of photoacclimation induced at low temperature exclusively in the highly freezing-tolerant genotype. In conclusion, enhanced expression of Rubisco activase splicing variants caused an increase in Rubisco activity during pre-hardening and cold acclimation in the more freezing-tolerant Lolium perenne genotype. The induction of the transcript variant representing the large isoform may be an important element of increasing the carbon assimilation rate supporting the photochemical mechanism of photosynthetic acclimation to cold. PMID:27152456

  15. Selective deactivation of gibberellins below the shoot apex is critical to flowering but not to stem elongation of Lolium.

    PubMed

    King, Rod W; Mander, Lewis N; Asp, Torben; MacMillan, Colleen P; Blundell, Cheryl A; Evans, Lloyd T

    2008-03-01

    Gibberellins (GAs) cause dramatic increases in plant height and a genetic block in the synthesis of GA(1) explains the dwarfing of Mendel's pea. For flowering, it is GA(5) which is important in the long-day (LD) responsive grass, Lolium. As we show here, GA(1) and GA(4) are restricted in their effectiveness for flowering because they are deactivated by C-2 hydroxylation below the shoot apex. In contrast, GA(5) is effective because of its structural protection at C-2. Excised vegetative shoot tips rapidly degrade [14C]GA(1), [14C]GA(4), and [14C]GA(20) (>80% in 6 h), but not [14C]GA(5). Coincidentally, genes encoding two 2beta-oxidases and a putative 16-17-epoxidase were most expressed just below the shoot apex (<3 mm). Further down the immature stem (>4 mm), expression of these GA deactivation genes is reduced, so allowing GA(1) and GA(4) to promote sub-apical stem elongation. Subsequently, GA degradation declines in florally induced shoot tips and these GAs can become active for floral development. Structural changes which stabilize GA(4) confirm the link between florigenicity and restricted GA 2beta-hydroxylation (e.g. 2alpha-hydroxylation and C-2 di-methylation). Additionally, a 2-oxidase inhibitor (Trinexapac Ethyl) enhanced the activity of applied GA(4), as did limiting C-16,17 epoxidation in 16,17-dihydro GAs or after C-13 hydroxylation. Overall, deactivation of GA(1) and GA(4) just below the shoot apex effectively restricts their florigenicity in Lolium and, conversely, with GA(5), C-2 and C-13 protection against deactivation allows its high florigenicity. Speculatively, such differences in GA access to the shoot apex of grasses may be important for separating floral induction from inflorescence emergence and thus could influence their survival under conditions of herbivore predation. PMID:19825541

  16. [The toxic and protective effects of Polygonum multiflorum on normal and liver injured rats based on the symptom-based prescription theory].

    PubMed

    Pang, Jing-yao; Bai, Zhao-fang; Niu, Ming; Tu, Can; Ma, Zhi-jie; Zhao, Yan-ling; Zhao, Kui-jun; You, Yun; Wang, Jia-bo; Xiao, Xiao-he

    2015-08-01

    The dosage-efficacy/toxicity relationship of the 50% alcohol extracts of Polygonum multiflorum was comparatively investigated on either normal or CCl4-induced chronic liver injury rats, by determining the general condition, serum biochemical indices and liver histopathology, coupled with the factor analysis. The dosages were 10 and 20 g raw materials per kg body weight. Compared with the normal control group, the normal high dose group showed significant increases of the serum alanine transaminase (ALT), total bilirubin (TBIL), high mobility group box 1 (HMGB-1) and interleukin-1β (IL-1β) (P < 0.05 or P < 0.01), as well the frequent incidences of inflammatory cell infiltration, hepatic sinus enlargement and fiber stripes formation in histopathological sections. Compared with the model control group, the model low dose group showed significant declines of serum ALT, aspartate transaminase (AST) and total bile acid (TBA) (P < 0.05), as well the alleviation of vacuoles of hepatocytes, but no amelioration of the inflammatory cell infiltration and fibrous tissue hyperplasia; moreover, the model high dose group showed significant degeneration declines of serum HMGB-1, tumor necrosis factor-α (TNF-α) and IL-1β (P < 0.05, P < 0.01), as well the evident alleviation of vacuoles degeneration of hepatocytes, inflammatory cells infiltration and fibrosis degree. The factor analysis showed that the low dosage treatment had almost neither injuring effect on the normal rats nor protective effect on the model rats; while the high dosage treatment showed observable injuring effect on the normal rats, expressed by the significant increases of the factor-1 (HMGB-1, TNF-α and IL-1β as the main contributors) and factor-2 (TBIL, ALT and TBA as the main contributors) relative to the normal control group. The liver protective effect of the high dosage treatment could be observed with the significant reduction of the factor-1, indicating the effective alleviation of the expression of

  17. Evidence chain-based causality identification in herb-induced liver injury: exemplification of a well-known liver-restorative herb Polygonum multiflorum.

    PubMed

    Wang, Jiabo; Ma, Zhijie; Niu, Ming; Zhu, Yun; Liang, Qingsheng; Zhao, Yanling; Song, Jingyuan; Bai, Zhaofang; Zhang, Yaming; Zhang, Ping; Li, Na; Meng, Yakun; Li, Qi; Qin, Lushan; Teng, Guangju; Cao, Junling; Li, Baosen; Chen, Shilin; Li, Yonggang; Zou, Zhengsheng; Zhou, Honghao; Xiao, Xiaohe

    2015-12-01

    Herbal medicines have recently been recognized as the second most common cause of drug-induced liver injury (DILI) in the United States. However, reliable methods to identify the DILI causality of some herbs, such as Heshouwu (dried root of Polygonum multiflorum), remain lacking. In this study, a total of 12 307 inpatients with liver dysfunction and 147 literature-reported cases of Heshouwu DILI were screened. A general algorithm indicated that only 22.5% (9/40) and 30.6% (45/147) of all hospitalization and literature case reports, respectively, demonstrate the high probability of DILI causality of Heshouwu. By contrast, 95% (19/20) of all cases prospectively investigated by pharmacognosy, phytochemistry, and metabolomic tests exhibited highly probable causality, including a patient who was previously incorrectly attributed and a case that was excluded from Heshouwu causality by pharmacognostic evidence. Toxin (heavy metals, pesticides, and mycotoxins) contamination was also excluded from Heshouwu DILI causality. The objectivity of these screening methods for Heshouwu DILI diagnosis addresses safety concerns regarding stilbene-containing herbal medicines and dietary supplements. PMID:26459430

  18. TSG (2,3,5,4'-Tetrahydroxystilbene-2-O- β -D-glucoside) from the Chinese Herb Polygonum multiflorum Increases Life Span and Stress Resistance of Caenorhabditis elegans.

    PubMed

    Büchter, Christian; Zhao, Liang; Havermann, Susannah; Honnen, Sebastian; Fritz, Gerhard; Proksch, Peter; Wätjen, Wim

    2015-01-01

    2,3,5,4'-Tetrahydroxystilbene-2-O-β-D-glucoside (TSG) was isolated from Polygonum multiflorum, a plant which is traditionally used as an anti-ageing drug. We have analysed ageing-related effects of TSG in the model organism C. elegans in comparison to resveratrol. TSG exerted a high antioxidative capacity both in a cell-free assay and in the nematode. The antioxidative capacity was even higher compared to resveratrol. Presumably due to its antioxidative effects, treatment with TSG decreased the juglone-mediated induction of the antioxidative enzyme SOD-3; the induction of the GST-4 by juglone was diminished slightly. TSG increased the resistance of C. elegans against lethal thermal stress more prominently than resveratrol (50 μM TSG increased mean survival by 22.2%). The level of the ageing pigment lipofuscin was decreased after incubation with the compound. TSG prolongs the mean, median, and maximum adult life span of C. elegans by 23.5%, 29.4%, and 7.2%, respectively, comparable to the effects of resveratrol. TSG-mediated extension of life span was not abolished in a DAF-16 loss-of-function mutant strain showing that this ageing-related transcription factor is not involved in the effects of TSG. Our data show that TSG possesses a potent antioxidative capacity, enhances the stress resistance, and increases the life span of the nematode C. elegans. PMID:26075030

  19. Evolutionary history of tall fescue morphotypes inferred from molecular phylogenetics of the Lolium-Festuca species complex

    PubMed Central

    2010-01-01

    Background The agriculturally important pasture grass tall fescue (Festuca arundinacea Schreb. syn. Lolium arundinaceum (Schreb.) Darbysh.) is an outbreeding allohexaploid, that may be more accurately described as a species complex consisting of three major (Continental, Mediterranean and rhizomatous) morphotypes. Observation of hybrid infertility in some crossing combinations between morphotypes suggests the possibility of independent origins from different diploid progenitors. This study aims to clarify the evolutionary relationships between each tall fescue morphotype through phylogenetic analysis using two low-copy nuclear genes (encoding plastid acetyl-CoA carboxylase [Acc1] and centroradialis [CEN]), the nuclear ribosomal DNA internal transcribed spacer (rDNA ITS) and the chloroplast DNA (cpDNA) genome-located matK gene. Other taxa within the closely related Lolium-Festuca species complex were also included in the study, to increase understanding of evolutionary processes in a taxonomic group characterised by multiple inter-specific hybridisation events. Results Putative homoeologous sequences from both nuclear genes were obtained from each polyploid species and compared to counterparts from 15 diploid taxa. Phylogenetic reconstruction confirmed F. pratensis and F. arundinacea var. glaucescens as probable progenitors to Continental tall fescue, and these species are also likely to be ancestral to the rhizomatous morphotype. However, these two morphotypes are sufficiently distinct to be located in separate clades based on the ITS-derived data set. All four of the generated data sets suggest independent evolution of the Mediterranean and Continental morphotypes, with minimal affinity between cognate sequence haplotypes. No obvious candidate progenitor species for Mediterranean tall fescues were identified, and only two putative sub-genome-specific haplotypes were identified for this morphotype. Conclusions This study describes the first phylogenetic analysis of

  20. Allelopathic Potential of Switchgrass ( Panicum virgatum L.) on Perennial Ryegrass ( Lolium perenne L.) and Alfalfa ( Medicago sativa L.)

    NASA Astrophysics Data System (ADS)

    Shui, Junfeng; An, Yu; Ma, Yongqing; Ichizen, Nobumasa

    2010-10-01

    This study investigated allelopathy and its chemical basis in nine switchgrass ( Panicum virgatum L.) accessions. Perennial ryegrass ( Lolium perenne L.) and alfalfa ( Medicago sativa L.) were used as test species. Undiluted aqueous extracts (5 g plant tissue in 50 ml water) from the shoots and roots of most of the switchgrass accessions inhibited the germination and growth of the test species. However, the allelopathic effect of switchgrass declined when extracts were diluted 5- or 50-fold. Seedling growth was more sensitive than seed germination as an indicator of allelopathic effect. Allelopathic effect was related to switchgrass ecotype but not related to ploidy level. Upland accessions displayed stronger allelopathic potential than lowland accessions. The aqueous extract from one switchgrass accession was separated into phenols, organic acids, neutral chemicals, and alkaloids, and then these fractions were bioassayed to test for allelopathic potential. Alkaloids had the strongest allelopathic effect among the four chemical fractions. In summary, the results indicated that switchgrass has allelopathic potential; however, there is not enough evidence to conclude that allelopathic advantage is the main factor that has contributed to the successful establishment of switchgrass on China’s Loess Plateau.

  1. Symbiont-mediated changes in Lolium arundinaceum inducible defenses: evidence from changes in gene expression and leaf composition.

    PubMed

    Sullivan, Terrence J; Rodstrom, John; Vandop, Joshua; Librizzi, James; Graham, Candace; Schardl, Christopher L; Bultman, Thomas L

    2007-01-01

    Plants have multiple strategies to deal with herbivory, ranging from chemical or physical defenses to tolerating damage and allocating resources for regrowth. Grasses usually tolerate herbivory, but for some cool-season grasses, their strategy may depend upon their interactions with intracellular symbionts. Neotyphodium endophytes are common symbionts in pooid grasses, and, for some host species, they provide chemical defenses against both vertebrate and invertebrate herbivores. Here, it was tested whether defenses provided by Neotyphodium coenophialum in Lolium arundinaceum (tall fescue) are inducible by both mechanical damage and herbivory from an invertebrate herbivore, Spodoptera frugiperda (fall armyworm), via a bioassay and by quantifying mRNA expression for lolC, a gene required for loline biosysnthesis. Both mechanical and herbivore damage had a negative effect on the reproduction of a subsequent herbivore, Rhopalosiphum padi (bird cherry-oat aphid), and herbivore damage caused an up-regulation of lolC. Uninfected grass hosts also had significantly higher foliar N% and lower C:N ratio compared with infected hosts, suggesting greater allocation to growth rather than defense. For L. arundinaceum, N. coenophialum appears to switch its host's defensive strategy from tolerance via compensation to resistance. PMID:17822401

  2. Effects of amendments on copper, cadmium, and lead phytoextraction by Lolium perenne from multiple-metal contaminated solution.

    PubMed

    Gunawardana, B; Singhal, N; Johnson, A

    2011-03-01

    Chemical amendments can increase metal uptake by plant roots and translocation to shoots, however their effectiveness can be influenced by the presence of other amendments and metal ions in a multiple-metal environment. A range of amendments and combinations were tested to explore their effect on phytoextraction of Cu, Cd, and Pb by perennial ryegrass (Lolium perenne) from solutions containing one or more of these metals. The amendments studied included EDDS (an aminopolycarboxylic acid), histidine (an amino acid), citric acid (an organic acid), rhamnolipid (a biosurfactant) and sulfate (an inorganic ligand). For all amendment treatments, the presence of multiple metals in solution reduced shoot concentrations of Cd and Cu, while Pb levels in shoots were generally enhanced by the presence of Cu. Although slightly toxic to the plants, EDDS (1 mM) was the most effective individual amendment for enhancing shoot metal uptake and translocation from solution without significantly reducing biomass yield. The combination Rhm+Cit+EDDS resulted in the highest shoot metal concentrations of all the treatments but also caused severe phytotoxicity. Amendment combinations Rhm+His and Sulf+Cit were less toxic for plant growth while moderately enhancing metal mass accumulation in shoots and thus could be considered as alternative treatments for enhanced phytoextraction. PMID:21598788

  3. Toxicity of eight polycyclic aromatic compounds to red clover (Trifolium pratense), ryegrass (Lolium perenne), and mustard (Sinapsis alba).

    PubMed

    Sverdrup, Line E; Krogh, Paul Henning; Nielsen, Torben; Kjaer, Christian; Stenersen, Jørgen

    2003-12-01

    The effect of eight polycyclic aromatic compounds (PACs) on the seed emergence and early life-stage growth of three terrestrial plants (Sinapsis alba, Trifolium pratense and Lolium perenne) were studied in a greenhouse, using a Danish agricultural soil with an organic carbon content of 1.6%. After three weeks of exposure, seed emergence and seedling weight (fresh weight and dry weight) were determined. Exposure concentrations were verified with chemical analysis. The substances tested were four polycyclic aromatic hydrocarbons (fluoranthene, pyrene, phenanthrene and fluorene), the N-, S-, and O-substituted analogues of fluorene (carbazole, dibenzothiophene and dibenzofuran, respectively), and the quinoline representative acridine. Seedling growth was a far more sensitive endpoint than seed emergence for all substances. Concentrations estimated to give a 20% reduction of seedling fresh weight (EC20-values) ranged from 36 to 290 mgkg(-1) for carbazole, 43 to 93 mgkg(-1) for dibenzofuran, 37 to 110 mgkg(-1) for dibenzothiophene, 140 to 650 mgkg(-1) for fluoranthene, 55 to 380 mgkg(-1) for fluorene, 37 to 300 mgkg(-1) for phenanthrene, and 49 to 1300 mgkg(-1) for pyrene. For acridine, no toxicity was observed within the concentration range tested (1-1000 mgkg(-1)). As illustrated by the EC20-values, there was a rather large difference in sensitivity between the species, and T. pratense was the most sensitive of the species tested. PMID:14505722

  4. Exudation of alcohol and aldehyde sugars from roots of defoliated Lolium perenne L. grown under sterile conditions.

    PubMed

    Clayton, Stephen J; Read, Derek B; Murray, Philip J; Gregory, Peter J

    2008-11-01

    Root exudates were collected over a 27 day period from defoliated and non-defoliated Lolium perenne L. plants grown under sterile conditions in microlysimeters. Eleven individual sugars, including both aldehyde and alcohol sugars, were identified and quantified with a gas chromatograph-mass spectrometer (GC-MS). There was no change in the number of sugars present between 7 and 27 days, but the exudation of alcohol sugars decreased rapidly at about day 12. Xylose and glucose were present in the largest amounts. Defoliation initially increased the total amount of sugars in the exudates, but continuous defoliation reduced total sugar exudation by 16% and induced changes in the exudation patterns of individual sugars. Defoliation enhanced exudation of erythritol, threitol, and xylitol, reduced exudation of glucose and arabitol, but had little effect on the amounts of other sugars exuded. The more complex 6 C, 5 OH aldehyde sugars, especially glucose, showed changes earlier and to a greater extent (17 days), than the 5 C, 4 OH (xylose and ribose) and 6 C 4 OH (fucose) aldehyde groups. These findings confirm the general finding that repeated defoliation reduces the quantity of total sugars exuded, but the pattern of release of individual sugars is complex and variable. PMID:18815840

  5. Metabolic profiles of Lolium perenne are differentially affected by nitrogen supply, carbohydrate content, and fungal endophyte infection.

    PubMed

    Rasmussen, Susanne; Parsons, Anthony J; Fraser, Karl; Xue, Hong; Newman, Jonathan A

    2008-03-01

    Lolium perenne cultivars differing in their capacity to accumulate water soluble carbohydrates (WSCs) were infected with three strains of fungal Neotyphodium lolii endophytes or left uninfected. The endophyte strains differed in their alkaloid profiles. Plants were grown at two different levels of nitrogen (N) supply in a controlled environment. Metabolic profiles of blades were analyzed using a variety of analytical methods. A total of 66 response variables were subjected to a principle components analysis and factor rotation. The first three rotated factors (46% of the total variance) were subsequently analyzed by analysis of variance. At high N supply nitrogenous compounds, organic acids and lipids were increased; WSCs, chlorogenic acid (CGA), and fibers were decreased. The high-sugar cultivar 'AberDove' had reduced levels of nitrate, most minor amino acids, sulfur, and fibers compared to the control cultivar 'Fennema', whereas WSCs, CGA, and methionine were increased. In plants infected with endophytes, nitrate, several amino acids, and, magnesium were decreased; WSCs, lipids, some organic acids, and CGA were increased. Regrowth of blades was stimulated at high N, and there was a significant endophyte x cultivar interaction on regrowth. Mannitol, a fungal specific sugar alcohol, was significantly correlated with fungal biomass. Our findings suggest that effects of endophytes on metabolic profiles of L. perenne can be considerable, depending on host plant characteristics and nutrient supply, and we propose that a shift in carbon/N ratios and in secondary metabolite production as seen in our study is likely to have impacts on herbivore responses. PMID:18218971

  6. Testing water-soluble carbohydrate QTL effects in perennial ryegrass (Lolium perenne L.) by marker selection.

    PubMed

    Turner, L B; Farrell, M; Humphreys, M O; Dolstra, O

    2010-11-01

    Water-soluble carbohydrates (WSC) are an important factor determining the nutritional value of grass forage and development of genetic markers for selection of WSC traits in perennial ryegrass would benefit future breeding programmes. Quantitative trait loci (QTLs) for WSC have been published for an F(2) ryegrass mapping family. Markers showing significant associations with these QTLs were used to design narrow-based populations with homozygosity for target QTLs. Founders were selected from within the mapping family. The divergent populations produced were analysed for WSC content in the glasshouse and the field. There was evidence of complex interactions between WSC content and other factors and traits, including the scale of assessment, time/degree of sward establishment and other forage quality parameters. Differences between the divergent pairs of the various populations were small. However, differences observed between the founder selection groups were maintained and the roles of the QTL regions in regulating forage WSC content were confirmed. In general, the individual divergent populations exploited only a limited extent of the large phenotypic variation available within the mapping family. However, this study sets the scene for exploring the opportunities for marker-assisted breeding strategies for complex traits in obligate out-breeding species, and the challenges of doing this are discussed. PMID:20617301

  7. Investigating the Mechanism of Glyphosate Resistance in Rigid Ryegrass (Lolium rigidum)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glyphosate is a broad-spectrum herbicide that has been used extensively for more than 20 yr. The first glyphosate-resistant weed biotype appeared in 1996; it involved a rigid ryegrass population from Australia that exhibited an LD50 value approximately 10-fold higher than that of sensitive biotypes....

  8. Exogenous Application of Citric Acid Ameliorates the Adverse Effect of Heat Stress in Tall Fescue (Lolium arundinaceum).

    PubMed

    Hu, Longxing; Zhang, Zhifei; Xiang, Zuoxiang; Yang, Zhijian

    2016-01-01

    Citric acid may be involved in plant response to high temperature. The objective of this study was to investigate whether exogenous citric acid could improve heat tolerance in a cool-season turfgrass species, tall fescue (Lolium arundinaceum), and to determine the physiological mechanisms of citric acid effects on heat stress tolerance. The grasses were subjected to four citric acid levels (0, 0.2, 2, and 20 mM) and two temperature levels (25/20 and 35/30 ± 0.5°C, day/night) treatments in growth chambers. Heat stress increased an electrolyte leakage (EL) and malonaldehyde (MDA) content, while reduced plant growth, chlorophyll (Chl) content, photochemical efficiency (Fv/Fm), root activity and antioxidant enzyme activities (superoxide dismutase, SOD; catalase, CAT; peroxidase, POD). External citric acid alleviated the detrimental effects of heat stress on tall fescue, which was evidenced by decreased EL and MDA content, and improved plant growth under stress conditions. Additionally, the reduction in Chl content, Fv/Fm, SOD, POD, CAT and root activity were ameliorated in citric acid treated plants under heat stressed conditions. High temperature induced the expression of heat shock protein (HSP) genes, which exhibited greater expression levels after citric acid treatment under heat stress. These results suggest that exogenous citric acid application may alleviate growth and physiological damage caused by high temperature. In addition, the exogenously applied citric acid might be responsible for maintaining membrane stability, root activity, and activation of antioxidant response and HSP genes which could contribute to the protective roles of citric acid in tall fescue responses to heat stress. PMID:26925085

  9. Evaluation of a cost effective technique for treating aquaculture water discharge using Lolium perenne Lam as a biofilter.

    PubMed

    Nduwimana, André; Yang, Xiang-Long; Wang, Li-Ren

    2007-01-01

    Wastewater stabilization ponds generate low cost by-products that are useful for agriculture. The utilization of these by-products for soil amendment and as a source of nutrients for plants requires a high level of sanitation and stabilization of the organic matter, to maintain acceptable levels of soil, water and air quality. In this study, two aquaculture wastewater treatment systems; recirculating system and a floating plant bed system were designed to improve the quality of irrigation water in local communities with low income. In both systems the grass species Lolium perenne Lam was used as a plant biofilter while vegetable specie Amaranthus viridis was used to evaluate the performance of the system and the suitability of the phyto-treated water for irrigation. It was found that the harmful material removal rate for recirculating system was 88.9% for TAN (total ammonia nitrogen), 90% for NO2(-)-N, 64.8% for NO3(-)-N while for floating plant bed system 82.7% for TAN, 82% for NO2(-)-N and 60.5% for NO3(-)-N. Comparative analysis of the efficiency of waste element removal between the two systems revealed that both systems performed well, however, plant growth was not robust for floating plant bed system while recirculating system is energy consuming. Although both systems did not attain sufficient levels of TN (total nitrogen) and TP (total phosphorus) load reduction, the treatment with L. perenne remarkably improved the irrigation water quality. A. viridis plants irrigated with the phyto-treated discharge water had lesser concentrations of heavy metals in their tissues compared to those irrigated with untreated discharge. The control plants irrigated with untreated discharge were also found to be highly lignified with few stems and small leaves. PMID:17966513

  10. Latitudinal variation in ambient UV-B radiation is an important determinant of Lolium perenne forage production, quality, and digestibility

    PubMed Central

    Comont, David; Winters, Ana; Gomez, Leonardo D; McQueen-Mason, Simon J; Gwynn-Jones, Dylan

    2013-01-01

    Few studies to date have considered the responses of agriculturally important forage grasses to UV-B radiation. Yet grasses such as Lolium perenne have a wide current distribution, representing exposure to a significant variation in ambient UV-B. The current study investigated the responses of L. perenne (cv. AberDart) to a simulated latitudinal gradient of UV-B exposure, representing biologically effective UV-B doses at simulated 70, 60, 50, 40, and 30° N latitudes. Aspects of growth, soluble compounds, and digestibility were assessed, and results are discussed in relation to UV-B effects on forage properties and the implications for livestock and bio-ethanol production. Aboveground biomass production was reduced by approximately 12.67% with every 1 kJ m–2 day–1 increase in biologically weighted UV-B. As a result, plants grown in the highest UV-B treatment had a total biomass of just 13.7% of controls. Total flavonoids were increased by approximately 76% by all UV-B treatments, while hydroxycinnamic acids increased in proportion to the UV-B dose. Conversely, the digestibility of the aboveground biomass and concentrations of soluble fructans were reduced by UV-B exposure, although soluble sucrose, glucose, and fructose concentrations were unaffected. These results highlight the capacity for UV-B to directly affect forage productivity and chemistry, with negative consequences for digestibility and bioethanol production. Results emphasize the need for future development and distribution of L. perenne varieties to take UV-B irradiance into consideration. PMID:23580749

  11. Exogenous Classic Phytohormones Have Limited Regulatory Effects on Fructan and Primary Carbohydrate Metabolism in Perennial Ryegrass (Lolium perenne L.).

    PubMed

    Gasperl, Anna; Morvan-Bertrand, Annette; Prud'homme, Marie-Pascale; van der Graaff, Eric; Roitsch, Thomas

    2015-01-01

    Fructans are polymers of fructose and one of the main constituents of water-soluble carbohydrates in forage grasses and cereal crops of temperate climates. Fructans are involved in cold and drought resistance, regrowth following defoliation and early spring growth, seed filling, have beneficial effects on human health and are used for industrial processes. Perennial ryegrass (Lolium perenne L.) serves as model species to study fructan metabolism. Fructan metabolism is under the control of both synthesis by fructosyltransferases (FTs) and breakdown through fructan exohydrolases (FEHs). The accumulation of fructans can be triggered by high sucrose levels and abiotic stress conditions such as drought and cold stress. However, detailed studies on the mechanisms involved in the regulation of fructan metabolism are scarce. Since different phytohormones, especially abscisic acid (ABA), are known to play an important role in abiotic stress responses, the possible short term regulation of the enzymes involved in fructan metabolism by the five classical phytohormones was investigated. Therefore, the activities of enzymes involved in fructan synthesis and breakdown, the expression levels for the corresponding genes and levels for water-soluble carbohydrates were determined following pulse treatments with ABA, auxin (AUX), ethylene (ET), gibberellic acid (GA), or kinetin (KIN). The most pronounced fast effects were a transient increase of FT activities by AUX, KIN, ABA, and ET, while minor effects were evident for 1-FEH activity with an increased activity in response to KIN and a decrease by GA. Fructan and sucrose levels were not affected. This observed discrepancy demonstrates the importance of determining enzyme activities to obtain insight into the physiological traits and ultimately the plant phenotype. The comparative analyses of activities for seven key enzymes of primary carbohydrate metabolism revealed no co-regulation between enzymes of the fructan and sucrose pool

  12. Metabolic changes and associated cytokinin signals in response to nitrate assimilation in roots and shoots of Lolium perenne.

    PubMed

    Roche, Jessica; Love, Jonathan; Guo, Qianqian; Song, Jiancheng; Cao, Mingshu; Fraser, Karl; Huege, Jan; Jones, Chris; Novák, Ondřej; Turnbull, Matthew H; Jameson, Paula E

    2016-04-01

    The efficiency of inorganic nitrogen (N) assimilation is a critical component of fertilizer use by plants and of forage production in Lolium perenne, an important pasture species worldwide. We present a spatiotemporal description of nitrate use efficiency in terms of metabolic responses and carbohydrate remobilization, together with components of cytokinin signal transduction following nitrate addition to N-impoverished plants. Perennial ryegrass (L. perenne cv. Grasslands Nui) plants were grown for 10 weeks in unfertilized soil and then treated with nitrate (5 mM) hydroponically. Metabolomic analysis by gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry revealed a dynamic interaction between N and carbon metabolism over a week-long time course represented by the relative abundance of amino acids, tricarboxylic acid intermediates and stored water-soluble carbohydrates (WSCs). The initial response to N addition was characterized by a rapid remobilization of carbon stores from the low-molecular weight WSC, along with an increase in N content and assimilation into free amino acids. Subsequently, the shoot became the main source of carbon through remobilization of a large pool of high-molecular weight WSC. Associated quantification of cytokinin levels and expression profiling of putative cytokinin response regulator genes by quantitative reverse transcription polymerase chain reaction support a role for cytokinin in the mediation of the response to N addition in perennial ryegrass. The presence of high levels of cis-zeatin-type cytokinins is discussed in the context of hormonal homeostasis under the stress of steady-state N deficiency. PMID:26661753

  13. Exogenous Application of Citric Acid Ameliorates the Adverse Effect of Heat Stress in Tall Fescue (Lolium arundinaceum)

    PubMed Central

    Hu, Longxing; Zhang, Zhifei; Xiang, Zuoxiang; Yang, Zhijian

    2016-01-01

    Citric acid may be involved in plant response to high temperature. The objective of this study was to investigate whether exogenous citric acid could improve heat tolerance in a cool-season turfgrass species, tall fescue (Lolium arundinaceum), and to determine the physiological mechanisms of citric acid effects on heat stress tolerance. The grasses were subjected to four citric acid levels (0, 0.2, 2, and 20 mM) and two temperature levels (25/20 and 35/30 ± 0.5°C, day/night) treatments in growth chambers. Heat stress increased an electrolyte leakage (EL) and malonaldehyde (MDA) content, while reduced plant growth, chlorophyll (Chl) content, photochemical efficiency (Fv/Fm), root activity and antioxidant enzyme activities (superoxide dismutase, SOD; catalase, CAT; peroxidase, POD). External citric acid alleviated the detrimental effects of heat stress on tall fescue, which was evidenced by decreased EL and MDA content, and improved plant growth under stress conditions. Additionally, the reduction in Chl content, Fv/Fm, SOD, POD, CAT and root activity were ameliorated in citric acid treated plants under heat stressed conditions. High temperature induced the expression of heat shock protein (HSP) genes, which exhibited greater expression levels after citric acid treatment under heat stress. These results suggest that exogenous citric acid application may alleviate growth and physiological damage caused by high temperature. In addition, the exogenously applied citric acid might be responsible for maintaining membrane stability, root activity, and activation of antioxidant response and HSP genes which could contribute to the protective roles of citric acid in tall fescue responses to heat stress. PMID:26925085

  14. Metabolic profiling of Lolium perenne shows functional integration of metabolic responses to diverse subtoxic conditions of chemical stress.

    PubMed

    Serra, Anne-Antonella; Couée, Ivan; Renault, David; Gouesbet, Gwenola; Sulmon, Cécile

    2015-04-01

    Plant communities are confronted with a great variety of environmental chemical stresses. Characterization of chemical stress in higher plants has often been focused on single or closely related stressors under acute exposure, or restricted to a selective number of molecular targets. In order to understand plant functioning under chemical stress conditions close to environmental pollution conditions, the C3 grass Lolium perenne was subjected to a panel of different chemical stressors (pesticide, pesticide degradation compound, polycyclic aromatic hydrocarbon, and heavy metal) under conditions of seed-level or root-level subtoxic exposure. Physiological and metabolic profiling analysis on roots and shoots revealed that all of these subtoxic chemical stresses resulted in discrete physiological perturbations and complex metabolic shifts. These metabolic shifts involved stressor-specific effects, indicating multilevel mechanisms of action, such as the effects of glyphosate and its degradation product aminomethylphosphonic acid on quinate levels. They also involved major generic effects that linked all of the subtoxic chemical stresses with major modifications of nitrogen metabolism, especially affecting asparagine, and of photorespiration, especially affecting alanine and glycerate. Stress-related physiological effects and metabolic adjustments were shown to be integrated through a complex network of metabolic correlations converging on Asn, Leu, Ser, and glucose-6-phosphate, which could potentially be modulated by differential dynamics and interconversion of soluble sugars (sucrose, trehalose, fructose, and glucose). Underlying metabolic, regulatory, and signalling mechanisms linking these subtoxic chemical stresses with a generic impact on nitrogen metabolism and photorespiration are discussed in relation to carbohydrate and low-energy sensing. PMID:25618145

  15. Olivine Weathering in Soil, and Its Effects on Growth and Nutrient Uptake in Ryegrass (Lolium perenne L.): A Pot Experiment

    PubMed Central

    ten Berge, Hein F. M.; van der Meer, Hugo G.; Steenhuizen, Johan W.; Goedhart, Paul W.; Knops, Pol; Verhagen, Jan

    2012-01-01

    Mineral carbonation of basic silicate minerals regulates atmospheric CO2 on geological time scales by locking up carbon. Mining and spreading onto the earth's surface of fast-weathering silicates, such as olivine, has been proposed to speed up this natural CO2 sequestration (‘enhanced weathering’). While agriculture may offer an existing infrastructure, weathering rate and impacts on soil and plant are largely unknown. Our objectives were to assess weathering of olivine in soil, and its effects on plant growth and nutrient uptake. In a pot experiment with perennial ryegrass (Lolium perenne L.), weathering during 32 weeks was inferred from bioavailability of magnesium (Mg) in soil and plant. Olivine doses were equivalent to 1630 (OLIV1), 8150, 40700 and 204000 (OLIV4) kg ha−1. Alternatively, the soluble Mg salt kieserite was applied for reference. Olivine increased plant growth (+15.6%) and plant K concentration (+16.5%) in OLIV4. At all doses, olivine increased bioavailability of Mg and Ni in soil, as well as uptake of Mg, Si and Ni in plants. Olivine suppressed Ca uptake. Weathering estimated from a Mg balance was equivalent to 240 kg ha−1 (14.8% of dose, OLIV1) to 2240 kg ha−1 (1.1%, OLIV4). This corresponds to gross CO2 sequestration of 290 to 2690 kg ha−1 (29 103 to 269 103 kg km−2.) Alternatively, weathering estimated from similarity with kieserite treatments ranged from 13% to 58% for OLIV1. The Olsen model for olivine carbonation predicted 4.0% to 9.0% weathering for our case, independent of olivine dose. Our % values observed at high doses were smaller than this, suggesting negative feedbacks in soil. Yet, weathering appears fast enough to support the ‘enhanced weathering’ concept. In agriculture, olivine doses must remain within limits to avoid imbalances in plant nutrition, notably at low Ca availability; and to avoid Ni accumulation in soil and crop. PMID:22912685

  16. Synergetic effects of DA-6/GA₃ with EDTA on plant growth, extraction and detoxification of Cd by Lolium perenne.

    PubMed

    He, Shanying; Wu, Qiuling; He, Zhenli

    2014-12-01

    Research is needed to improve efficiency of phytoextraction of heavy metals from contaminated soils. A pot experiment was carried out to study the effects of plant growth regulators (PGRs) (diethyl aminoethyl hexanoate (C18H33NO8, DA-6) and gibberellic acid 3 (C19H22O6, GA3)) and/or EDTA on Cd extraction, subcellular distribution and chemical forms in Lolium perenne. The addition of EDTA or PGRs significantly enhanced Cd extraction efficiency (P<0.05), with the decreasing order of: 1 μM DA-6>10 μM DA-6>10 μM GA3>2.5 mmol kg(-1) EDTA>other treatments of PGR alone. PGRs+EDTA resulted in a further increase in Cd extraction efficiency, with EDTA+1 μM DA-6 being the most efficient. At the subcellular level, about 44-57% of Cd was soluble fraction, 18-44% in cell walls, and 12-25% in cellular organelles fraction. Chemical speciation analysis showed that 40-54% of Cd was NaCl extractable, 7-23% HAc extractable, followed by other fractions. EDTA increased the proportions of Cd in soluble and cellular organelles fraction, as well as the metal migration in shoot; therefore, the toxicity to plant increased and plant growth was inhibited. Conversely, PGRs fixed more Cd in cell walls and reduced Cd migration in shoot; thus, metal toxicity was reduced. In addition, PGRs promoted plant biomass growth significantly (P<0.05), with 1 μM DA-6 being the most effective. A combination of DA-6/GA3 with EDTA can alleviate the adverse effect of EDTA on plant growth, and the treatment of EDTA+1 μM DA-6 appears to be optimal for improving the remediation efficiency of L. perenne for Cd contaminated soil. PMID:24999226

  17. Metabolic profiling of Lolium perenne shows functional integration of metabolic responses to diverse subtoxic conditions of chemical stress

    PubMed Central

    Serra, Anne-Antonella; Couée, Ivan; Renault, David; Gouesbet, Gwenola; Sulmon, Cécile

    2015-01-01

    Plant communities are confronted with a great variety of environmental chemical stresses. Characterization of chemical stress in higher plants has often been focused on single or closely related stressors under acute exposure, or restricted to a selective number of molecular targets. In order to understand plant functioning under chemical stress conditions close to environmental pollution conditions, the C3 grass Lolium perenne was subjected to a panel of different chemical stressors (pesticide, pesticide degradation compound, polycyclic aromatic hydrocarbon, and heavy metal) under conditions of seed-level or root-level subtoxic exposure. Physiological and metabolic profiling analysis on roots and shoots revealed that all of these subtoxic chemical stresses resulted in discrete physiological perturbations and complex metabolic shifts. These metabolic shifts involved stressor-specific effects, indicating multilevel mechanisms of action, such as the effects of glyphosate and its degradation product aminomethylphosphonic acid on quinate levels. They also involved major generic effects that linked all of the subtoxic chemical stresses with major modifications of nitrogen metabolism, especially affecting asparagine, and of photorespiration, especially affecting alanine and glycerate. Stress-related physiological effects and metabolic adjustments were shown to be integrated through a complex network of metabolic correlations converging on Asn, Leu, Ser, and glucose-6-phosphate, which could potentially be modulated by differential dynamics and interconversion of soluble sugars (sucrose, trehalose, fructose, and glucose). Underlying metabolic, regulatory, and signalling mechanisms linking these subtoxic chemical stresses with a generic impact on nitrogen metabolism and photorespiration are discussed in relation to carbohydrate and low-energy sensing. PMID:25618145

  18. Latitudinal variation in ambient UV-B radiation is an important determinant of Lolium perenne forage production, quality, and digestibility.

    PubMed

    Comont, David; Winters, Ana; Gomez, Leonardo D; McQueen-Mason, Simon J; Gwynn-Jones, Dylan

    2013-05-01

    Few studies to date have considered the responses of agriculturally important forage grasses to UV-B radiation. Yet grasses such as Lolium perenne have a wide current distribution, representing exposure to a significant variation in ambient UV-B. The current study investigated the responses of L. perenne (cv. AberDart) to a simulated latitudinal gradient of UV-B exposure, representing biologically effective UV-B doses at simulated 70, 60, 50, 40, and 30° N latitudes. Aspects of growth, soluble compounds, and digestibility were assessed, and results are discussed in relation to UV-B effects on forage properties and the implications for livestock and bio-ethanol production. Aboveground biomass production was reduced by approximately 12.67% with every 1 kJ m(-2) day(-1) increase in biologically weighted UV-B. As a result, plants grown in the highest UV-B treatment had a total biomass of just 13.7% of controls. Total flavonoids were increased by approximately 76% by all UV-B treatments, while hydroxycinnamic acids increased in proportion to the UV-B dose. Conversely, the digestibility of the aboveground biomass and concentrations of soluble fructans were reduced by UV-B exposure, although soluble sucrose, glucose, and fructose concentrations were unaffected. These results highlight the capacity for UV-B to directly affect forage productivity and chemistry, with negative consequences for digestibility and bioethanol production. Results emphasize the need for future development and distribution of L. perenne varieties to take UV-B irradiance into consideration. PMID:23580749

  19. Exogenous Classic Phytohormones Have Limited Regulatory Effects on Fructan and Primary Carbohydrate Metabolism in Perennial Ryegrass (Lolium perenne L.)

    PubMed Central

    Gasperl, Anna; Morvan-Bertrand, Annette; Prud'homme, Marie-Pascale; van der Graaff, Eric; Roitsch, Thomas

    2016-01-01

    Fructans are polymers of fructose and one of the main constituents of water-soluble carbohydrates in forage grasses and cereal crops of temperate climates. Fructans are involved in cold and drought resistance, regrowth following defoliation and early spring growth, seed filling, have beneficial effects on human health and are used for industrial processes. Perennial ryegrass (Lolium perenne L.) serves as model species to study fructan metabolism. Fructan metabolism is under the control of both synthesis by fructosyltransferases (FTs) and breakdown through fructan exohydrolases (FEHs). The accumulation of fructans can be triggered by high sucrose levels and abiotic stress conditions such as drought and cold stress. However, detailed studies on the mechanisms involved in the regulation of fructan metabolism are scarce. Since different phytohormones, especially abscisic acid (ABA), are known to play an important role in abiotic stress responses, the possible short term regulation of the enzymes involved in fructan metabolism by the five classical phytohormones was investigated. Therefore, the activities of enzymes involved in fructan synthesis and breakdown, the expression levels for the corresponding genes and levels for water-soluble carbohydrates were determined following pulse treatments with ABA, auxin (AUX), ethylene (ET), gibberellic acid (GA), or kinetin (KIN). The most pronounced fast effects were a transient increase of FT activities by AUX, KIN, ABA, and ET, while minor effects were evident for 1-FEH activity with an increased activity in response to KIN and a decrease by GA. Fructan and sucrose levels were not affected. This observed discrepancy demonstrates the importance of determining enzyme activities to obtain insight into the physiological traits and ultimately the plant phenotype. The comparative analyses of activities for seven key enzymes of primary carbohydrate metabolism revealed no co-regulation between enzymes of the fructan and sucrose pool

  20. The photosynthetic acclimation of Lolium perenne growing in a free-air CO{sub 2} enrichment (FACE) system

    SciTech Connect

    Bryant, J.B. |

    1994-11-01

    Stands of Ryegrass (Lolium perenne L. cv. Bastion) were grown in the field at ambient or elevated (600{mu}mol/mol) CO{sub 2} concentration, high (560Kg/ha) or low (140Kg/ha) nitrogen addition and with a frequent (every 4 weeks) or infrequent (every 8 weeks) cutting regime. Plants were in the second year of a 3 year experiment. Exposure to elevated CO{sub 2} was carried out with a Free-Air CO{sub 2} Enrichment (FACE) system which provides the most {open_quote}realistic{close_quote} system of CO{sub 2} fumigation currently available. Elevated CO{sub 2} increased diurnal CO{sub 2} assimilation by between 34 and 88% whilst reducing rates of stomatal conductance by between 1 and 42%. However, analysis of the A vs. Ci response showed considerable acclimation of the photosynthetic apparatus in response to elevated CO{sub 2} - Vc{sub max} as an in vivo measure of RubisCO activity, decreased by between 29 and 35% in high CO{sub 2}, whilst J{sub max}, as a measure of the RubP regeneration capacity, showed no significant change. Two out of three additional perennial grassland species studied showed similar acclamatory behavior to Ryegrass. Diurnal assimilation rate, J{sub max} and, in most cases, Vc{sub max}, increased significantly directly after cutting of Ryegrass stands, but nitrogen treatment had little effect on any of these parameters. Neither stomatal density, stomatal index nor stomatal pore length of Ryegrass were significantly altered by growth in elevated CO{sub 2}. The results are discussed in terms of the limitation imposed on maximizing photosynthetic and growth responses of Ryegrass at elevated CO{sub 2}, by the ability of perennial species to increase long-term sink capacity under these conditions.

  1. Regulation of Flowering in the Long-Day Grass Lolium temulentum by Gibberellins and the FLOWERING LOCUS T Gene

    PubMed Central

    King, Rod W.; Moritz, Thomas; Evans, Lloyd T.; Martin, Jerome; Andersen, Claus H.; Blundell, Cheryl; Kardailsky, Igor; Chandler, Peter M.

    2006-01-01

    Seasonal control of flowering often involves leaf sensing of daylength coupled to time measurement and generation and transport of florigenic signals to the shoot apex. We show that transmitted signals in the grass Lolium temulentum may include gibberellins (GAs) and the FLOWERING LOCUS T (FT) gene. Within 2 h of starting a florally inductive long day (LD), expression of a 20-oxidase GA biosynthetic gene increases in the leaf; its product, GA20, then increases 5.7-fold versus short day; its substrate, GA19, decreases equivalently; and a bioactive product, GA5, increases 4-fold. A link between flowering, LD, GAs, and GA biosynthesis is shown in three ways: (1) applied GA19 became florigenic on exposure to LD; (2) expression of LtGA20ox1, an important GA biosynthetic gene, increased in a florally effective LD involving incandescent lamps, but not with noninductive fluorescent lamps; and (3) paclobutrazol, an inhibitor of an early step of GA biosynthesis, blocked flowering, but only if applied before the LD. Expression studies of a 2-oxidase catabolic gene showed no changes favoring a GA increase. Thus, the early LD increase in leaf GA5 biosynthesis, coupled with subsequent doubling in GA5 content at the shoot apex, provides a substantial trail of evidence for GA5 as a LD florigen. LD signaling may also involve transport of FT mRNA or protein because expression of LtFT and LtCONSTANS increased rapidly, substantially (>80-fold for FT), and independently of GA. However, because a LD from fluorescent lamps induced LtFT expression but not flowering, the nature of the light response of FT requires clarification. PMID:16581877

  2. Long-Day Induction of Flowering in Lolium temulentum Involves Sequential Increases in Specific Gibberellins at the Shoot Apex1

    PubMed Central

    King, Rod W.; Moritz, Thomas; Evans, Lloyd T.; Junttila, Olavi; Herlt, Anthony J.

    2001-01-01

    One challenge for plant biology has been to identify floral stimuli at the shoot apex. Using sensitive and specific gas chromatography-mass spectrometry techniques, we have followed changes in gibberellins (GAs) at the shoot apex during long day (LD)-regulated induction of flowering in the grass Lolium temulentum. Two separate roles of GAs in flowering are indicated. First, within 8 h of an inductive LD, i.e. at the time of floral evocation, the GA5 content of the shoot apex doubled to about 120 ng g−1 dry weight. The concentration of applied GA5 required for floral induction of excised apices (R.W. King, C. Blundell, L.T. Evans [1993] Aust J Plant Physiol 20: 337–348) was similar to that in the shoot apex. Leaf-applied [2H4] GA5 was transported intact from the leaf to the shoot apex, flowering being proportional to the amount of GA5 imported. Thus, GA5 could be part of the LD stimulus for floral evocation of L. temulentum or, alternatively, its increase at the shoot apex could follow import of a primary floral stimulus. Later, during inflorescence differentiation and especially after exposure to additional LD, a second GA action was apparent. The content of GA1 and GA4 in the apex increased greatly, whereas GA5 decreased by up to 75%. GA4 applied during inflorescence differentiation strongly promoted flowering and stem elongation, whereas it was ineffective for earlier floral evocation although it caused stem growth at all times of application. Thus, we conclude that GA1 and GA4 are secondary, late-acting LD stimuli for inflorescence differentiation in L. temulentum. PMID:11598236

  3. [Enhancement of GA3 and EDTA on Lolium perenne to remediate Pb contaminated soil and its detoxification mechanism].

    PubMed

    Wu, Qiu-Ling; Wang, Wen-Chu; He, Shan-Ying

    2014-10-01

    A pot experiment was conducted to study the effects of plant growth regulator GA3 and metal chelate EDTA on enhancing the remediation of Pb contaminated soil, and the detoxification mechanism of Lolium perenne grown on Pb contaminated soil at 250 and 500 mg · kg(-1). The results showed that cell wall deposition and vacuolar compartmentalization played important roles in the detoxification of Pb in L. perenne shoot. The addition of EDTA alone increased Pb concentration in plants and Pb proportions in soluble fraction and organelles fraction, and enhanced the toxicity of Pb to plant, leading to the significant reduction of the plant biomass (P < 0.05). Foliar spray of lower concentration of GA3 (1 μmol · L(-1) or 10 μmol · L(-1)) alone significantly increased Pb accumulation by L. perenne (P < 0.05), but Pb proportions in soluble and organelles fraction were decreased, which alleviated the adverse effects of Pb on plant, thus improving the growth of plants (P < 0.05), with 1 μmol · L(-1) GA3 being the most effective. In contract, the addition of 100 μmol · L(-1) GA3 decreased Pb concentration in L. perenne, but increased the proportions of Pb in soluble fraction and organelles fraction, resulting in the reduction of plant biomass. Lower concen- tration of GA3 might alleviate the adverse effects of Pb and/or EDTA on plant, since the biomass amounts in the different treatments were in order of GA3 alone of lower concentration > GA3 of lower concentration + EDTA > EDTA alone. The combination application of low concentration of GA3 and EDTA showed a synergistic effect on the Pb accumulation in L. perenne (P < 0.05). Especially, Pb concentration in shoot and Pb extraction efficiency reached 1250.6 mg · kg(-1) and 1.1%, respec- tively, under the treatment of EDTA + 1 μmol L(-1) GA3 on the Pb 500 mg · kg(-1) soil. Therefore, the application of 1 μmol · L(-1) GA3 along with EDTA appeared to be a potential approach for phytoremediation of Pb contaminated soil

  4. The annual variation in stomatal ammonia compensation point of rye grass ( Lolium perenne L.) leaves in an intensively managed grassland

    NASA Astrophysics Data System (ADS)

    van Hove, L. W. A.; Heeres, P.; Bossen, M. E.

    The stomatal ammonia compensation point for ammonia (NH 3) of an intensively managed pasture of rye grass ( Lolium perenne L.) was followed from mid January till November 2000. Leaf samples were taken every week. Simultaneously, the ambient NH 3 concentration was measured. Meteorological data (temperature, wind speed, rainfall and radiance) were collected from a nearby field station. The vacuum infiltration technique was used to isolate the apoplastic solution of the leaves. From the determined ammonium (NH 4+) concentration and pH in the apoplast, the gaseous NH 3 concentration inside the leaves was calculated, i.e. the so-called stomatal compensation point ( χs). Temperature appeared to have a predominant effect on χs, partly by affecting the equilibrium between gaseous NH 3 inside the leaf and NH 3 dissolved in the apoplast and partly by affecting physiological processes influencing the NH 4+ concentration in the apoplast. Results of the present study suggest that these temperature effects were counteracting. On one hand temperature increase during early spring stimulated NH 3 volatilisation from the apoplast, on the other hand it led to a decline in apoplastic NH 4+ from 0.9 to 0.2 mM, thereby diminishing the emission potential of the leaf. The low NH 4+ concentrations during spring and summer coincided with a low total leaf N content (<3% dw). However, there was no clear relationship between these two variables. The total N content of the leaf tissue is therefore an inadequate parameter for prediction of the potential NH 3 emission from rye grass leaves. No annual trend was found for the apoplast pH. With a few exceptions, pH varied between 5.9 and 6.5 throughout the experimental period. The calculated values for χs varied between 0.5 and 4 μg m -3. The gaseous NH 3 concentrations inside the grass leaves were, with a few exceptions, always smaller than the measured ambient NH 3 concentrations. The present study indicates that under the current ambient NH 3

  5. Development of a DNA Sequence-Based Multiplex Test for Rapid Differentiation of Ryegrass Growth Types

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Annual (Lolium multiflorum Lam.) and perennial (Lolium perenne L.) ryegrasses are two common forage species in temperate regions. Identifying annual ryegrass contamination in perennial ryegrass seed lots has been of major interest in the seed industry for many years. The objective of our work over t...

  6. Using advances in plant genomics to develop a DNA-based test to benefit the ryegrass seed industry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Annual (Lolium multiflorum Lam.) and perennial (Lolium perenne L.) ryegrasses are two common forage species in temperate regions. Identifying annual ryegrass contamination in perennial ryegrass seed lots has been of major interest in the seed industry for many years. The objective of our work over t...

  7. A sensitive PCR-based assay to detect Neotyphodium fungi in seed and plant tissue of tall fescue and ryegrass spp.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A polymerase chain reaction (PCR)-based method for detection of Neotyphodium endophytes in seed and plant tissue from tall fescue (Festuca arundinacea Schreb.), Italian (Lolium multiflorum Lam.) and perennial (Lolium perenne L.) ryegrasses was developed. Based on DNA mixture tests and bulk seed anal...

  8. Heavy-metal absorption by perennial ryegrass and Swiss chard grown in potted soils amended with ashes from 18 municipal refuse incinerators. [Lolium perenne; Beta vulgaris L

    SciTech Connect

    Bache, C.A.; Lisk, D.J. )

    1990-01-01

    Perennial ryegrass (Lolium perenne) and swiss chard (Beta vulgaris L.) were grown in pots of mardin silt loam soil amended with 5 or 10% by weight of fly ash, bottom ash, or mixtures of both from 18 municipal refuse incinerators representing about one-fourth of all those operating in the US. The ash and plant material were analyzed for total cadmium, lead, and zinc. The correlation coefficients (r) for the concentration of cadmium, lead, and zinc in the ashes and that in the following crops were, respectively, as follows: ryegrass (first cutting), 0.9964, 0.7600, 0.9699; ryegrass (second cutting), 0.9946, 0.6895, 0.9474; swiss chard, 0.9153, 0.7609., 0.9580. Poor plant growth occurred in a few of the treatments containing ash notably higher in dissolved solids, cadmium, and zinc. The origin and association of heavy metals in refuse ash and their reactions in soils are reviewed.

  9. TSG (2,3,5,4′-Tetrahydroxystilbene-2-O-β-D-glucoside) from the Chinese Herb Polygonum multiflorum Increases Life Span and Stress Resistance of Caenorhabditis elegans

    PubMed Central

    Büchter, Christian; Zhao, Liang; Fritz, Gerhard; Proksch, Peter

    2015-01-01

    2,3,5,4′-Tetrahydroxystilbene-2-O-β-D-glucoside (TSG) was isolated from Polygonum multiflorum, a plant which is traditionally used as an anti-ageing drug. We have analysed ageing-related effects of TSG in the model organism C. elegans in comparison to resveratrol. TSG exerted a high antioxidative capacity both in a cell-free assay and in the nematode. The antioxidative capacity was even higher compared to resveratrol. Presumably due to its antioxidative effects, treatment with TSG decreased the juglone-mediated induction of the antioxidative enzyme SOD-3; the induction of the GST-4 by juglone was diminished slightly. TSG increased the resistance of C. elegans against lethal thermal stress more prominently than resveratrol (50 μM TSG increased mean survival by 22.2%). The level of the ageing pigment lipofuscin was decreased after incubation with the compound. TSG prolongs the mean, median, and maximum adult life span of C. elegans by 23.5%, 29.4%, and 7.2%, respectively, comparable to the effects of resveratrol. TSG-mediated extension of life span was not abolished in a DAF-16 loss-of-function mutant strain showing that this ageing-related transcription factor is not involved in the effects of TSG. Our data show that TSG possesses a potent antioxidative capacity, enhances the stress resistance, and increases the life span of the nematode C. elegans. PMID:26075030

  10. Effect of ryegrass (Lolium perenne L.) roots inoculation using different arbuscular mycorrhizal fungi (AMF) species on sorption of iron-cyanide (Fe-CN) complexes

    NASA Astrophysics Data System (ADS)

    Sut, Magdalena; Boldt-Burisch, Katja; Raab, Thomas

    2016-04-01

    Soils and groundwater on sites of the former Manufactured Gas Plants (MGPs) are contaminated with various complex iron-cyanides (Fe-CN). Phytoremediation is a promising tool in stabilization and remediation of Fe-CN affected soils, however, it can be a challenging task due to extreme adverse and toxic conditions. Phytoremediation may be enhanced via rhizosphere microbial activity, which can cooperate on the degradation, transformation and uptake of the contaminants. Recently, increasing number of scientist reports improved plants performance in the removal of toxic compounds with the support of arbuscular mycorrhizae fungi (AMF). Series of batch experiments using potassium hexacyanoferrate (II) solutions, in varying concentrations, were used to study the effect of ryegrass roots (Lolium perenne L.) inoculation with Rhizophagus irregularis and a mixture of Rhizophagus irregularis, Funneliformis mosseae, Rhizophagus aggregatus, and Claroideoglomus etunicatum on Fe-CN sorption. Results indicated significantly higher colonization of R. irregularis than for the mixture of AMF species on ryegrass roots. Sorption experiments revealed significantly higher reduction of total CN and free CN content in the mycorrhizal roots, indicating greater cyanide decrease in the treatment inoculated with R. irregularis. Our study indicates contribution of AM fungi in phytoremediation of Fe-CN contaminated soil.

  11. Genome-Wide Transcriptional Profiling and Metabolic Analysis Uncover Multiple Molecular Responses of the Grass Species Lolium perenne Under Low-Intensity Xenobiotic Stress

    PubMed Central

    Serra, Anne-Antonella; Couée, Ivan; Heijnen, David; Michon-Coudouel, Sophie; Sulmon, Cécile; Gouesbet, Gwenola

    2015-01-01

    Lolium perenne, which is a major component of pastures, lawns, and grass strips, can be exposed to xenobiotic stresses due to diffuse and residual contaminations of soil. L. perenne was recently shown to undergo metabolic adjustments in response to sub-toxic levels of xenobiotics. To gain insight in such chemical stress responses, a de novo transcriptome analysis was carried out on leaves from plants subjected at the root level to low levels of xenobiotics, glyphosate, tebuconazole, and a combination of the two, leading to no adverse physiological effect. Chemical treatments influenced significantly the relative proportions of functional categories and of transcripts related to carbohydrate processes, to signaling, to protein-kinase cascades, such as Serine/Threonine-protein kinases, to transcriptional regulations, to responses to abiotic or biotic stimuli and to responses to phytohormones. Transcriptomics-based expressions of genes encoding different types of SNF1 (sucrose non-fermenting 1)-related kinases involved in sugar and stress signaling or encoding key metabolic enzymes were in line with specific qRT-PCR analysis or with the important metabolic and regulatory changes revealed by metabolomic analysis. The effects of pesticide treatments on metabolites and gene expression strongly suggest that pesticides at low levels, as single molecule or as mixture, affect cell signaling and functioning even in the absence of major physiological impact. This global analysis of L. perenne therefore highlighted the interactions between molecular regulation of responses to xenobiotics, and also carbohydrate dynamics, energy dysfunction, phytohormones and calcium signaling. PMID:26734031

  12. Adhesion of Bacteroides succinogenes in pure culture and in the presence of Ruminococcus flavefaciens to cell walls in leaves of perennial ryegrass (Lolium perenne).

    PubMed Central

    Latham, M J; Brooker, B E; Pettipher, G L; Harris, P J

    1978-01-01

    Bacteroides succinogenes and Ruminococcus flavefaciens are two of the most important cellulolytic bacteria in the rumen. Adhesion of B. succinogenes in pure culture, and in mixed culture with R. flavefaciens, to the various types of cell walls in sections of perennial ryegrass (Lolium perenne L. cultivar S24) leaves was examined by transmission and scanning electron microscopy. B. succinogenes adhered to the cut edges of most plant cell walls except those of the meta- and protoxylem. It also adhered, though in much smaller numbers, to the uncut surfaces of mesophyll, epidermal, and phloem cell walls. In mixed culture, both species adhered in significant numbers to the cut edges of most types of plant cell wall, but R. flavefaciens predominated on the epidermis, phloem, and sclerenchyma cell walls. B. succinogenes predominated on the cut edges and on the uncut surfaces of the mesophyll cell walls, and its ability to adhere to uncut surfaces of other cell walls was not affected by the presence of the ruminococcus. Both organisms rapidly digested the epidermal, mesophyll, and phloem cell walls. Zones of digestion were observed around bacteria of both species when attached to the lignified cell walls of the sclerenchyma, but not when attached to the lignified xylem vessels. Images PMID:567035

  13. Characterization of Proanthocyanidins from Seeds of Perennial Ryegrass (Lolium perenne L.) and Tall Fescue (Festuca arundinacea) by Liquid Chromatography-Mass Spectrometry.

    PubMed

    Fraser, Karl; Collette, Vern; Hancock, Kerry R

    2016-09-01

    Perennial ryegrass (Lolium perenne) and tall fescue (Festuca arundinacea) are forage species of the grass family (Poaceae) that are key components of temperate pasture-based agricultural systems. Proanthocyanidins (PAs) are oligomeric flavonoids that, when provided as part of a farm animal's diet, have been reported to improve animal production and health. Up to now, forage grasses have been deemed not to produce PAs. This paper reports for the first time the detection of polymerized PAs in aqueous methanolic extracts of seed tissue of both perennial ryegrass and tall fescue, using LC-MS/MS. We have determined the structure of the PAs to be trans-flavan-3-ol-based, consisting predominately of afzelechin and catechin and linked primarily by B-type bonds. Investigations into the leaf tissue of both species failed to detect any PAs. This discovery opens the possibility of using genetic engineering tools to achieve tannin accumulation in leaf tissue of perennial ryegrass and tall fescue. PMID:27532250

  14. The photosynthetic acclimation response of Lolium perenne to four years growth in a free-air CO{sub 2} enrichment (FACE) facility

    SciTech Connect

    Creasey, R.

    1996-11-01

    In this study, the photosynthetic responses of field grown Lolium perenne to ambient (354 {mu}mol mol{sup -1}) and elevated (600 {mu}mol mol{sup -1}) C{sub a} were measured. The experiment utilized the FACE facility at Eschikon, Switzerland; here the L. Perenne swards had been grown at two nitrogen treatments, with six cuts per year, for 4 years. The study revealed a significant decrease in Rubisco activity (Vcmax) in the low nitrogen FACE plots; this is consistent with the theories of source-sink imbalance resulting in feedback inhibition and down-regulation. Such negative acclimation was not wholly supported by diurnal investigations which revealed an average stimulation of 53.38% and 52.78% in the low and high nitrogen, respectively. However, light response curves and AI investigations also suggested down-regulation, especially in the low nitrogen. SI is expected to decrease in response to elevated C{sub a}, if any change is seen. This was indeed observed in the high nitrogen plots but for the low nitrogen a significant increase was found. Conclusions drawn from this project center around the implications of negative acclimation to future crop productivity. For instance, inter-specific differences in response to elevated C{sub a} may result in ecosystem changes and new management techniques may be necessary. However, real predictions cannot be made from leaf level studies alone as these may not represent the overall changes at the whole plant level.

  15. Effect of herbicide resistance endowing Ile-1781-Leu and Asp-2078-Gly ACCase gene mutations on ACCase kinetics and growth traits in Lolium rigidum

    PubMed Central

    Vila-Aiub, Martin M.; Yu, Qin; Han, Heping; Powles, Stephen B.

    2015-01-01

    The rate of herbicide resistance evolution in plants depends on fitness traits endowed by alleles in both the presence and absence (resistance cost) of herbicide selection. The effect of two Lolium rigidum spontaneous homozygous target-site resistance-endowing mutations (Ile-1781-Leu, Asp-2078-Gly) on both ACCase activity and various plant growth traits have been investigated here. Relative growth rate (RGR) and components (net assimilation rate, leaf area ratio), resource allocation to different organs, and growth responses in competition with a wheat crop were assessed. Unlike plants carrying the Ile-1781-Leu resistance mutation, plants homozygous for the Asp-2078-Gly mutation exhibited a significantly lower RGR (30%), which translated into lower allocation of biomass to roots, shoots, and leaves, and poor responses to plant competition. Both the negligible and significant growth reductions associated, respectively, with the Ile-1781-Leu and Asp-2078-Gly resistance mutations correlated with their impact on ACCase activity. Whereas the Ile-1781-Leu mutation showed no pleiotropic effects on ACCase kinetics, the Asp-2078-Gly mutation led to a significant reduction in ACCase activity. The impaired growth traits are discussed in the context of resistance costs and the effects of each resistance allele on ACCase activity. Similar effects of these two particular ACCase mutations on the ACCase activity of Alopecurus myosuroides were also confirmed. PMID:26019257

  16. Identification of extracellular siderophores and a related peptide from the endophytic fungus Epichloë festucae in culture and endophyte-infected Lolium perenne

    PubMed Central

    Koulman, Albert; Lee, T. Verne; Fraser, Karl; Johnson, Linda; Arcus, Vickery; Lott, J. Shaun; Rasmussen, Susanne; Lane, Geoffrey

    2012-01-01

    A number of genes encoding non-ribosomal peptide synthetases (NRPSs) have been identified in fungi of Epichloë/Neotyphodium species, endophytes of Pooid grasses, including sidN, putatively encoding a ferrichrome siderophore-synthesizing NRPS. Targeted gene replacement and complementation of sidN in Epichloë festucae has established that extracellular siderophore epichloënin A is the major product of the SidN enzyme complex (Johnson et al., 2007a). We report here high resolution mass spectrometric fragmentation experiments and NMR analysis of an isolated fraction establishing that epichloënin A is a siderophore of the ferrichrome family, comprising a cyclic sequence of four glycines, a glutamine and three Nδ-trans-anhydromevalonyl–Nδ-hydroxyornithine (AMHO) moieties. Epichloënin A is unusual among ferrichrome siderophores in comprising an octapeptide rather than hexapeptide sequence, and in incorporating a glutamine residue. During this investigation we have established that desferrichrome siderophores with pendant trans-AMHO groups can be distinguished from those with pendant cis-AMHO groups by the characteristic neutral loss of an hydroxyornithine moiety in the MS/MS spectrum. A minor component, epichloënin B, has been characterized as the triglycine variant by mass spectrometry. A peptide characterized by mass spectrometry as the putative deoxygenation product, epichloëamide has been detected together with ferriepichloënin A in guttation fluid from ryegrass (Lolium perenne) plants infected with wild-type E. festucae, but not in plants infected with the ΔsidN mutant strain, and also detected at trace levels in wild-type E. festucae fungal culture. PMID:22196939

  17. An Assessment of the Ability of the Stay‐green Phenotype in Lolium Species to Provide an Improved Protein Supply for Ruminants

    PubMed Central

    KINGSTON-SMITH, ALISON H.; BOLLARD, ANDREA L.; HUMPHREYS, MERVYN O.; THEODOROU, MICHAEL K.

    2002-01-01

    The stay‐green phenotype results from a naturally occurring mutation in which senescent leaves retain their chlorophyll and the associated apoprotein, LHCPII. Protection of this protein pool could deliver grass with enhanced protein content and could decrease the extent of protein degradation by plant proteases in the rumen. This would enhance the efficiency of protein utilization in livestock to the benefit of the environment. Field plots of stay‐green and wild‐type Lolium perenne were defoliated at intervals to simulate grazing. There were variations in foliar protein content and proteolysis throughout the year, but no significant differences between genotypes when material was analysed fresh or after it was cut and dried to simulate hay‐making, which possibly induced senescence. In a subsequent experiment with stay‐green and wild‐type L. temulentum, increased protein retention and decreased protein degradability were observed in stay‐green leaves that were allowed to senescence naturally and extensively on the plant. That there is no difference between the two L. perenne genotypes suggests that as a field crop in grazed pastures the stay‐green genotype would not confer a nutritional advantage in terms of protein degradability. It is possible that grazing promotes a high proportion of non‐senescent to senescent leaf material within the sward and thus any advantage conferred by the stay‐green phenotype would be effectively masked by an abundance of mature foliage. It is suggested that the stay‐green trait would be of benefit in areas where agricultural practice permits extensive natural senescence to occur. PMID:12102529

  18. The photosynthetic acclimation of Lolium perenne in response to three years growth in a free-air CO{sub 2} enrichment (FACE) system

    SciTech Connect

    Hymus, G.J. |

    1996-08-01

    Pure stands of Ryegrass were in their third year of growth in the field, exposed to either ambient (355 {mu}mol mol{sup -1}), or elevated (600 {mu}mol mol{sup -1}) atmospheric CO{sub 2} concentration. A Free-Air CO{sub 2} Enrichment (FACE) system was used to maintain the elevated CO{sub 2} concentration whilst limiting experimental constraints on the field conditions. The theoretically predicted increase in the net rates of CO{sub 2} uptake per unit leaf area (A {mu}mol mol{sup -1}) as a consequence, primarily, of the suppression of photorespiration by CO{sub 2} a competitive inhibitor of RubP oxygenation by Rubisco, was observed for the Lolium perenne studied. Also observed was a general decline in leaf evapotranspiration (E) consistent with observations of increased water use efficiency of crops grown in elevated CO{sub 2}. Enhancement of leaf A in the FACE grown L. perenne ranged from 26.5 1 % to 44.95% over the course of a diurnal set of measurements. Whilst reductions in leaf E reached a maximum of 16.61% over the same diurnal course of-measurements. The increase in A was reconciled with an absence of the commonly observed decline in V{sub c}{sub max} as a measure of the maximum in vivo carboxylation capacity of the primary carboxylasing enzyme Rubisco and J{sub max} a measure of the maximum rate of electron transport. The manipulation of the source sink balance of the crop, stage of canopy regrowth or height in the canopy had no effect on the observation of a lack of response. The findings of this study will be interpreted with respect to the long term implications of C{sub 3} crops being able to adapt physiologically to maximize the potential benefits conferred by growth in elevated CO{sub 2}.

  19. Competition for water between walnut seedlings (Juglans regia) and rye grass (Lolium perenne) assessed by carbon isotope discrimination and delta18O enrichment.

    PubMed

    Picon-Cochard, C; Nsourou-Obame, A; Collet, C; Guehl, J M; Ferhi, A

    2001-02-01

    Container-grown walnut seedlings (Juglans regia L.) were subjected to competition with rye grass (Lolium perenne L.) and to a 2-week soil drying cycle. One and 2 weeks after the beginning of the drought treatment, H2 18O (delta approximately equals +100%) was added to the bottom layer of soil in the plant containers to create a vertical H2 18O gradient. Rye grass competition reduced aboveground and belowground biomass of the walnut seedlings by 60%, whereas drought had no effect. The presence of rye grass reduced the dry weight of walnut roots in the upper soil layer and caused a 50% reduction in lateral root length. Rye grass competition combined with the drought treatment reduced walnut leaf CO2 assimilation rate (A) and leaf conductance (gw) by 20 and 39%, respectively. Transpiration rates in rye grass, both at the leaf level and at the plant or tiller level, were higher than in walnut seedlings. Leaf intrinsic water-use efficiency (A/gw) of walnut seedlings increased in response to drought and no differences were observed between the single-species and mixed-species treatments, as confirmed by leaf carbon isotope discrimination measurements. Measurement of delta18O in soil and in plant xylem sap indicated that the presence of rye grass did not affect the vertical profile of soil water uptake by walnut seedlings. Walnut seedlings and rye grass withdrew water from the top and middle soil layers in well-watered conditions, whereas during the drought treatment, walnut seedlings obtained water from all soil layers, but rye grass took up water from the bottom soil layer only. PMID:11303649

  20. ProA, a transcriptional regulator of fungal fruiting body development, regulates leaf hyphal network development in the Epichloë festucae-Lolium perenne symbiosis.

    PubMed

    Tanaka, Aiko; Cartwright, Gemma M; Saikia, Sanjay; Kayano, Yuka; Takemoto, Daigo; Kato, Masashi; Tsuge, Takashi; Scott, Barry

    2013-11-01

    Transcription factors containing a Zn(II)2 Cys6 binuclear cluster DNA-binding domain are unique to fungi and are key regulators of fungal growth and development. The C6-Zn transcription factor, Pro1, in Sordaria macrospora is crucial for maturation of sexual fruiting bodies. In a forward genetic screen to identify Epichloë festucae symbiosis genes we identified a mutant with an insertion in proA. Plants infected with the proA mutant underwent premature senescence. Hyphae of ΔproA had a proliferative pattern of growth within the leaves of Lolium perenne. Targeted deletion of proA recapitulated this phenotype and introduction of a wild-type gene complemented the mutation. ΔproA was defective in hyphal fusion. qPCR analysis of E. festucae homologues of S. macrospora genes differentially expressed in Δpro1 identified esdC, encoding a glycogen-binding protein, as a target of ProA. Electrophoretic mobility shift assay analysis identified two binding sites for ProA in the intergenic region of esdC and a divergently transcribed gene, EF320. Both esdC and EF320 are highly expressed in a wild-type E. festucae-grass association but downregulated in a proA-mutant association. These results show that ProA is a key regulator of in planta specific growth of E. festucae, and therefore crucial for maintaining a mutualistic symbiotic interaction. PMID:23998652

  1. Does gibberellin biosynthesis play a critical role in the growth of Lolium perenne? Evidence from a transcriptional analysis of gibberellin and carbohydrate metabolic genes after defoliation

    PubMed Central

    Liu, Qianhe; Jones, Chris S.; Parsons, Anthony J.; Xue, Hong; Rasmussen, Susanne

    2015-01-01

    Global meat and milk production depends to a large extent on grazed pastures, with Lolium perenne being the major forage grass in temperate regions. Defoliation and subsequent regrowth of leaf blades is a major and essential event with respect to L. perenne growth and productivity. Following defoliation, carbohydrates (mainly fructans and sucrose) have to be mobilized from heterotrophic tissues to provide energy and carbon for regrowth of photosynthetic tissues. This mobilization of reserve carbohydrates requires a substantial change in the expression of genes coding for enzymes involved in carbohydrate metabolism. Here we tested the hypothesis that gibberellins (GA) are at the core of the processes regulating the expression of these genes. Thus, we examined the transcript profiles of genes involved in carbohydrate and GA metabolic pathways across a time course regrowth experiment. Our results show that following defoliation, the immediate reduction of carbohydrate concentrations in growing tissues is associated with a concomitant increase in the expression of genes encoding carbohydrate mobilizing invertases, and was also associated with a strong decrease in the expression of fructan synthesizing fructosyltransferase genes. We also show that the decrease in fructan levels is preceded by increased expression of the GA activating gene GA3-oxidase and decreased expression of the GA inactivating gene GA2-oxidase in sheaths. GA3-oxidase expression was negatively, while GA2-oxidase positively linked to sucrose concentrations. This study provides indicative evidence that gibberellins might play a role in L. perenne regrowth following defoliation and we hypothesize that there is a link between gibberellin regulation and sugar metabolism in L. perenne. PMID:26579182

  2. THE PHOTOSYNTHETIC RESPONSE OF THE PERENNIAL RYEGRASS (LOLIUM PERENNE) IN ITS FIFTH YEAR OF FREE-AIR CO{sub 2} ENRICHMENT (FACE) AT ESCHIKON, SWITZERLAND

    SciTech Connect

    ANDERSON,J.P.; LONG,STEPHEN,P.; WILLIAMS,J.

    1998-12-31

    Stands of Ryegrass (Lolium perenne L. cv.Bastion) were grown in the field at ambient or elevated (600 {micro}mol mol{sup {minus}1}) [CO{sub 2}], high (560 kg Ha{sup {minus}1} y{sup {minus}1}) or low (140 kg Ha{sup {minus}1} y{sup {minus}1}) nitrogen addition and were harvested five times a year during the growing season. The plants were sown during 1992, additional plots being sown during 1995. These were in their fifth year and second year of growth respectively. Exposure to elevated [CO{sub 2}] was carried out with a Free-Air CO{sub 2} Enrichment (FACE) system which provides the most realistic system of fumigation currently available. Elevated [CO{sub 2}] increased diurnal CO{sub 2} uptake by between 40 to 83% while reducing stomatal conductance by between 1 and 38% in all of the 1992 grown plants measured at high [CO{sub 2}]. Analysis of the A/c{sub i} response of 1992 grown plants showed no acclimation of the photosynthetic apparatus in response to elevated [CO{sub 2}]--both V{sub c,max} (a measure of the maximum in vivo rate of carboxylation) and J{sub max} (a measure of the maximum capacity for the regeneration of RuBP) showed no significant change during any of the periods of regrowth. In contrast the leaves of 1995 grown plants, appeared to be experiencing an acclimatory change in their photosynthetic apparatus in response to elevated [CO{sub 2}]. However, this negative response seemed to be removed directly after a harvest when the source:sink balance had increased. The apparent lack of an acclimatory response after almost 5 years of growth at elevated [CO{sub 2}], suggests that L. perenne may be close to achieving the appropriate photosynthetic adjustments which would allow it to attain a significantly higher photosynthetic potential.

  3. The photosynthetic response of the perennial ryegrass (Lolium perenne) in its fifth year of free-air CO(sub 2) enrichment (FACE) at Eschikon, Switzerland

    SciTech Connect

    Anderson, J.P.; Long, S.P.; Williams, J.

    1998-12-31

    Stands of Ryegrass (Lolium perenne L. cv.Bastion) were grown in the field at ambient or elevated (600 {micro}mol mol{sup {minus}1}) [CO{sub 2}], high (560 kg Ha{sup {minus}1} y{sup {minus}1}) or low (140 kg Ha{sup {minus}1} y{sup {minus}1}) nitrogen addition and were harvested five times a year during the growing season. The plants were sown during 1992, additional plots being sown during 1995. These were in their fifth year and second year of growth respectively. Exposure to elevated [CO{sub 2}] was carried out with a Free-Air CO{sub 2} Enrichment (FACE) system which provides the most realistic system of fumigation currently available. Elevated [CO{sub 2}] increased diurnal CO{sub 2} uptake by between 40 to 83% while reducing stomatal conductance by between 1 and 38% in all of the 1992 grown plants measured at high [CO{sub 2}]. Analysis of the A/c{sub i} response of 1992 grown plants showed no acclimation of the photosynthetic apparatus in response to elevated [CO{sub 2}] - both V{sub c,max} (a measure of the maximum in vivo rate of carboxylation) and J{sub max} (a measure of the maximum capacity for the regeneration of RuBP) showed no significant change during any of the periods of regrowth. In contrast the leaves of 1995 grown plants, appeared to be experiencing an acclimatory change in their photosynthetic apparatus in response to elevated [CO{sub 2}]. However, this negative response seemed to be removed directly after a harvest when the source:sink balance had increased. The apparent lack of an acclimatory response after almost 5 years of growth at elevated [CO{sub 2}], suggests that L. perenne may be close to achieving the appropriate photosynthetic adjustments which would allow it to attain a significantly higher photosynthetic potential.

  4. Population Structure, Genetic Variation, and Linkage Disequilibrium in Perennial Ryegrass Populations Divergently Selected for Freezing Tolerance

    PubMed Central

    Kovi, Mallikarjuna Rao; Fjellheim, Siri; Sandve, Simen R.; Larsen, Arild; Rudi, Heidi; Asp, Torben; Kent, Matthew Peter; Rognli, Odd Arne

    2015-01-01

    Low temperature is one of the abiotic stresses seriously affecting the growth of perennial ryegrass (Lolium perenne L.), and freezing tolerance is a complex trait of major agronomical importance in northern and central Europe. Understanding the genetic control of freezing tolerance would aid in the development of cultivars of perennial ryegrass with improved adaptation to frost. The plant material investigated in this study was an experimental synthetic population derived from pair-crosses among five European perennial ryegrass genotypes, representing adaptations to a range of climatic conditions across Europe. A total number of 80 individuals (24 of High frost [HF]; 29 of Low frost [LF], and 27 of Unselected [US]) from the second generation of the two divergently selected populations and an unselected (US) control population were genotyped using 278 genome-wide SNPs derived from perennial ryegrass transcriptome sequences. Our studies investigated the genetic diversity among the three experimental populations by analysis of molecular variance and population structure, and determined that the HF and LF populations are very divergent after selection for freezing tolerance, whereas the HF and US populations are more similar. Linkage disequilibrium (LD) decay varied across the seven chromosomes and the conspicuous pattern of LD between the HF and LF population confirmed their divergence in freezing tolerance. Furthermore, two Fst outlier methods; finite island model (fdist) by LOSITAN and hierarchical structure model using ARLEQUIN, both detected six loci under directional selection. These outlier loci are most probably linked to genes involved in freezing tolerance, cold adaptation, and abiotic stress. These six candidate loci under directional selection for freezing tolerance might be potential marker resources for breeding perennial ryegrass cultivars with improved freezing tolerance. PMID:26617611

  5. Quantitative Trait Locus (QTL) meta-analysis and comparative genomics for candidate gene prediction in perennial ryegrass (Lolium perenne L.)

    PubMed Central

    2012-01-01

    Background In crop species, QTL analysis is commonly used for identification of factors contributing to variation of agronomically important traits. As an important pasture species, a large number of QTLs have been reported for perennial ryegrass based on analysis of biparental mapping populations. Further characterisation of those QTLs is, however, essential for utilisation in varietal improvement programs. Results A bibliographic survey of perennial ryegrass trait-dissection studies identified a total of 560 QTLs from previously published papers, of which 189, 270 and 101 were classified as morphology-, physiology- and resistance/tolerance-related loci, respectively. The collected dataset permitted a subsequent meta-QTL study and implementation of a cross-species candidate gene identification approach. A meta-QTL analysis based on use of the BioMercator software was performed to identify two consensus regions for pathogen resistance traits. Genes that are candidates for causal polymorphism underpinning perennial ryegrass QTLs were identified through in silico comparative mapping using rice databases, and 7 genes were assigned to the p150/112 reference map. Markers linked to the LpDGL1, LpPh1 and LpPIPK1 genes were located close to plant size, leaf extension time and heading date-related QTLs, respectively, suggesting that these genes may be functionally associated with important agronomic traits in perennial ryegrass. Conclusions Functional markers are valuable for QTL meta-analysis and comparative genomics. Enrichment of such genetic markers may permit further detailed characterisation of QTLs. The outcomes of QTL meta-analysis and comparative genomics studies may be useful for accelerated development of novel perennial ryegrass cultivars with desirable traits. PMID:23137269

  6. Nitrous oxide emission factors for urine and dung from sheep fed either fresh forage rape (Brassica napus L.) or fresh perennial ryegrass (Lolium perenne L.).

    PubMed

    Luo, J; Sun, X Z; Pacheco, D; Ledgard, S F; Lindsey, S B; Hoogendoorn, C J; Wise, B; Watkins, N L

    2015-03-01

    In New Zealand, agriculture is predominantly based on pastoral grazing systems and animal excreta deposited on soil during grazing have been identified as a major source of nitrous oxide (N2O) emissions. Forage brassicas (Brassica spp.) have been increasingly used to improve lamb performance. Compared with conventional forage perennial ryegrass (Lolium perenne L.), a common forage in New Zealand, forage brassicas have faster growth rates, higher dry matter production and higher nutritive value. The aim of this study was to determine the partitioning of dietary nitrogen (N) between urine and dung in the excreta from sheep fed forage brassica rape (B. napus subsp. oleifera L.) or ryegrass, and then to measure N2O emissions when the excreta from the two different feed sources were applied to a pasture soil. A sheep metabolism study was conducted to determine urine and dung-N outputs from sheep fed forage rape or ryegrass, and N partitioning between urine and dung. Urine and dung were collected and then used in a field plot experiment for measuring N2O emissions. The experimental site contained a perennial ryegrass/white clover pasture on a poorly drained silt-loam soil. The treatments included urine from sheep fed forage rape or ryegrass, dung from sheep fed forage rape or ryegrass, and a control without dung or urine applied. N2O emission measurements were carried out using a static chamber technique. For each excreta type, the total N2O emissions and emission factor (EF3; N2O-N emitted during the 3- or 8-month measurement period as a per cent of animal urine or dung-N applied, respectively) were calculated. Our results indicate that, in terms of per unit of N intake, a similar amount of N was excreted in urine from sheep fed either forage rape or ryegrass, but less dung N was excreted from sheep fed forage rape than ryegrass. The EF3 for urine from sheep fed forage rape was lower compared with urine from sheep fed ryegrass. This may have been because of plant

  7. Resistance to glyphosate from altered herbicide translocation patterns.

    PubMed

    Preston, Christopher; Wakelin, Angela M

    2008-04-01

    Glyphosate-resistant weeds have evolved as a result of the intensive use of glyphosate for weed control. An alteration in the way glyphosate is translocated within the plant has been identified as a mechanism of glyphosate resistance in populations of Lolium rigidum Gaud., L. multiflorum Lam. and Conyza canadensis (L.) Cronq. In these resistant plants, glyphosate becomes concentrated in the leaves rather than being translocating throughout the plant. This type of resistance is inherited as a single dominant or semi-dominant allele. Resistance due to reduced translocation appears to be a common mechanism of resistance in L. rigidum and C. canadensis, probably because it provides a greater level of resistance than other mechanisms. This type of glyphosate resistance also appears to reduce the fitness of plants that carry it. This may influence how glyphosate resistance can be managed. PMID:18080284

  8. First report of Fusarium graminearum, F. asiaticum and F. cortaderiae as head blight pathogens of annual ryegrass in Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Members of the Fusarium graminearum species complex (FGSC) cause Fusarium head blight (FHB) of small grains and several grasses, including annual ryegrass (Lolium multiflorum Lam.), an important forage crop, but also a common weed in wheat, rice and maize agroecosystem in southern Brazil. Although i...

  9. Morphological traits associated with weed-suppressive ability of winter wheat against Italian ryegrass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Weed-suppressive wheat (Triticum aestivum L.) cultivars have been suggested as a complement to chemical and cultural methods of weed control. The objectives of this study were to assess the range of weed-suppressive ability against Italian ryegrass [Lolium perenne L. ssp. multiflorum (Lam.) Husnot] ...

  10. Nitrogen and Winter Cover Crop Effects on Spring and Summer Nutrient Uptake

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fertilization of bermudagrass [Cynodon dactylon (L.) Pers.] with swine-lagoon effluent in summer, April to September, does not match the period of productivity of the winter annual cover crops, annual ryegrass (Lolium multiflorum L.), cereal rye (Secale cereale), and berseem clover (Trifolium alexan...

  11. Spring nitrogen fertilization of ryegrass-bermudagrass for phytoremediation of phosphorus-enriched soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nitrogen fertilization of forage grasses is critical for optimizing biomass and utilization of manure soil nutrients. Field studies were conducted in 2007-09 to determine the effects of spring N fertilization on amelioration of high soil P when cool-season, annual ryegrass (Lolium multiflorum L.) is...

  12. Phytoremediation of high phosphorus soil by annual ryegrass and common bermudagrass harvest

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Removal of soil phosphorus (P) in crop harvest is a remediation option for soils high in P. This four-year field-plot study determined P uptake by annual ryegrass (ARG, Lolium multiflorum Lam.) and common bermudagrass (CB, Cynodon dactylon (L.) Pers.) from Ruston soil (fine-loamy, siliceous, thermic...

  13. Predation of warm-and cool-season grass seed by the common cricket (Acheta domesticus L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In field experiments we noted that one of the main predators of tall fescue (Festuca arundinacea Schreb.) and Italian ryegrass (Lolium multiflorum Lam.) seed was the field cricket (Gryllus sp.). To determine if there might be a seed predation preference among forage grasses a laboratory study was ...

  14. Dispersal and post-dispersal predation of Italian ryegrass seed in unimproved pasture.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dispersal and post-dispersal predation of Italian ryegrass seed in unimproved pasture. Italian ryegrass (Lolium multiflorum L.) can be a productive and high-quality cool-season forage, but is considered a weed in some pastures. Italian ryegrass does not form a persistent seed bank and needs to prod...

  15. Differential predation of forage seed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In recent field experiments we observed that the main invertebrate seed predators of overseeded tall fescue (Festuca arundinacea Schreb.) or Italian ryegrass (Lolium multiflorum Lam.) seed in unimproved pastures were harvester ants (Pogonomyrmex sp.) and common field crickets (Gryllus sp.) To determ...

  16. Performance by heifers grazing sod-seeded cool-season annuals seeded on different dates using two tillage intensities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A total of 120 Gelbvieh x Angus crossbred heifers (552'2.5 lb initial BW) grazed pastures of common bermudagrass [Cynodon dactylon (L.) Pers.] overseeded with wheat (Triticum aestivum L.) and annual ryegrass (Lolium multiflorum Lam.) for a 3-year study to compare the effect of seeding dates and till...

  17. Report of Glyceria declinata in Oregon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During official regulatory testing of grass seed shipments bound for Australia, seeds of a Glyceria species were detected in shipments of annual ryegrass (Lolium multiflorum Lam.). According to existing scientific literature, seven of the 18 Glyceria species known to occur in North America are foun...

  18. Stocker growth on rye and ryegrass pastures affects subsequent feedlot gains and carcass traits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stocker calves were stocked on annual rye (Secale cereale L.) and ryegrass (Lolium multiflorum Lam.) pastures using stocking strategies (STK) to create graded levels of gain to assess subsequent growth rates, feedlot performance, and carcass traits. During two consecutive years, yearling Angus, Here...

  19. Understanding Population.

    ERIC Educational Resources Information Center

    Mothner, Ira

    Activities and concerns of Ford Foundation supported population research and training centers are described in this report. The centers are concerned with population growth, consequences of growth for human welfare, forces that determine family planning, interrelations among population variables, economics of contraceptive distribution, and…

  20. Counting Populations

    ERIC Educational Resources Information Center

    Damonte, Kathleen

    2004-01-01

    Scientists use sampling to get an estimate of things they cannot easily count. A population is made up of all the organisms of one species living together in one place at the same time. All of the people living together in one town are considered a population. All of the grasshoppers living in a field are a population. Scientists keep track of the…

  1. [Population education].

    PubMed

    1977-01-01

    Goal of population education is to raise knowledge and comprehension of causes and consequences, either personal or social, of excessive population growth. These days it is possible to plan the growth and evolution of the population to reach a level of balance and harmony between number of inhabitants of a country, and the country's natural resoruces. general objectives of population education are: 1) knowledge of basic demographic processes; 2) knowledge of effects of evolution and growth of population on social and economic life inside the family and inside society; 3) family size as related to nutrition, health, education, and job; and, 4) knowledge of population dynamics which the individual can influence through personal behavior, i.e. age at marriage, and spacing and number of children. PMID:12309627

  2. Comparative Analyses Between Lolium/Festuca Introgression Lines and Rice Reveal the Major Fraction of Functionally Annotated Gene Models Is Located in Recombination-Poor/Very Recombination-Poor Regions of the Genome

    PubMed Central

    King, Julie; Armstead, Ian P.; Donnison, S. Iain; Roberts, Luned A.; Harper, John A.; Skøt, Kirsten; Elborough, Kieran; King, Ian P.

    2007-01-01

    Publication of the rice genome sequence has allowed an in-depth analysis of genome organization in a model monocot plant species. This has provided a powerful tool for genome analysis in large-genome unsequenced agriculturally important monocot species such as wheat, barley, rye, Lolium, etc. Previous data have indicated that the majority of genes in large-genome monocots are located toward the ends of chromosomes in gene-rich regions that undergo high frequencies of recombination. Here we demonstrate that a substantial component of the coding sequences in monocots is localized proximally in regions of very low and even negligible recombination frequencies. The implications of our findings are that during domestication of monocot plant species selection has concentrated on genes located in the terminal regions of chromosomes within areas of high recombination frequency. Thus a large proportion of the genetic variation available for selection of superior plant genotypes has not been exploited. In addition our findings raise the possibility of the evolutionary development of large supergene complexes that confer a selective advantage to the individual. PMID:17603095

  3. The endophytic symbiont Epichloë festucae establishes an epiphyllous net on the surface of Lolium perenne leaves by development of an expressorium, an appressorium-like leaf exit structure.

    PubMed

    Becker, Matthias; Becker, Yvonne; Green, Kimberly; Scott, Barry

    2016-07-01

    Epichloë festucae forms a mutualistic symbiotic association with Lolium perenne. This biotrophic fungus systemically colonizes the intercellular spaces of aerial tissues to form an endophytic hyphal network. E. festucae also grows as an epiphyte, but the mechanism for leaf surface colonization is not known. Here we identify an appressorium-like structure, which we call an expressorium that allows endophytic hyphae to penetrate the cuticle from the inside of the leaf to establish an epiphytic hyphal net on the surface of the leaf. We used a combination of scanning electron, transmission electron and confocal laser scanning microscopy to characterize this novel fungal structure and determine the composition of the hyphal cell wall using aniline blue and wheat germ agglutinin labelled with Alexafluor-488. Expressoria differentiate immediately below the cuticle in the leaf blade and leaf sheath intercalary cell division zones where the hyphae grow by tip growth. Differentiation of this structure requires components of both the NoxA and NoxB NADPH oxidase complexes. Major remodelling of the hyphal cell wall occurs following exit from the leaf. These results establish that the symbiotic association of E. festucae with L. perenne involves an interconnected hyphal network of both endophytic and epiphytic hyphae. PMID:26991322

  4. Population Blocks.

    ERIC Educational Resources Information Center

    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…

  5. MAINE POPULATION

    EPA Science Inventory

    MEPOP250 depicts Maine's 1950-1990 population data by town or Census in unorganized territories. Populations were compiled from US Census Bureau data where available or from Maine Municipal Information (mainly for older records). Unorganized towns with very low or zero pop...

  6. Population crises and population cycles.

    PubMed

    Russell, C; Russell, W M

    2000-01-01

    To prevent a population irretrievably depleting its resources, mammals have evolved a behavioural and physiological response to population crisis. When a mammalian population becomes dangerously dense, there is a reversal of behaviour. Co-operation and parental behaviour are replaced by competition, dominance and aggressive violence, leading to high mortality, especially of females and young, and a reduced population. The stress of overpopulation and the resulting violence impairs both the immune and the reproductive systems. Hence epidemics complete the crash of the population, and reproduction is slowed for three or four generations, giving the resources ample time to recover. In some mammal species, crisis and crisis response recur regularly, leading to cycles of population growth and relapse, oscillating about a fixed mean. Population crisis response and population cycles have been equally prominent in the history of human societies. But in man successive advances in food production have made possible growing populations, though with every such advance population soon outgrew resources again. Hence human cycles have been superimposed on a rising curve, producing a saw-tooth graph. Because advances in food production amounted to sudden disturbances in the relations between human populations and their environments, the crisis response in man has failed to avert famine and resource damage. In the large human societies evolved since the coming of settled agriculture and cities, the basic effects of violence, epidemics, famine and resource damage have been mediated by such specifically human disasters as inflation, unemployment, and political tyranny. An account of past crises, periods of relative relief from population pressure, and resulting cycles, is given for a number of regions: China, North Africa and Western Asia, the northern Mediterranean, and north-western Europe. The paper ends with an account of the present world-wide population crisis, and the solution

  7. Population policy.

    PubMed

    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

  8. Singapore: population.

    PubMed

    1980-08-01

    The population of Singapore reached 2,381,993 as of May, 1980. Singapore's population growth reached replacement level in 1975 thanks to the Singapore Family Planning and Population Board, which has maintained the demographic goal of a 2-child family, ultimately to reach zero population growth. Women have more opportunity to join the labor force. 21.2% of the working force in 1957 were women, compared to 48.1% in 1978. The government will impose restrictions on foreigners buying property in Singapore to protect local buyers from artificially inflated prices. Rentals of private and luxury apartments increased by 30% from 1979-80. The gross national product went up 8.5% to S$5,600 per year. The population estimates by ethnic groups in thousands are as follows: 180.4 Malay males, 174.7 females; 905.2 Chinese males, 893.9 females; 93.4 Indian males, 67.6 females; and 24.3 male others, 23.2 females. The majority of the population is aged 15-24. PMID:12233387

  9. Stellar Populations

    NASA Astrophysics Data System (ADS)

    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.

  10. Determination and characterization of cysteine, glutathione and phytochelatins (PC₂₋₆) in Lolium perenne L. exposed to Cd stress under ambient and elevated carbon dioxide using HPLC with fluorescence detection.

    PubMed

    Ju, Xue Hai; Tang, Shirong; Jia, Yan; Guo, Junkang; Ding, Yongzhen; Song, Zhengguo; Zhao, Yujie

    2011-06-15

    Metal-binding thiols, involved in detoxification mechanisms in plant and other organism under heavy metal stress, are receiving more and more attentions, and various methods have been developed to determine related thiols such as cysteine (Cys), glutathione (GSH) and phytochelatins (PCs). In present study, an HPLC method was established for simultaneous determination of Cys GSH and PC(2-6) after treatment with disulfide reductant of tris (2-carboxyethyl) phosphine hydrochloride (TCEP) and thiolyte reagent of monobromobimane (mBBr). The separation of thiol derivatives was performed on an Agilent Zorbax Eclipse XDB-C18 column (4.6 mm × 30 mm, 1.8 μm) with a linear gradient elution of 0.1% (v/v) trifluoroacetic acid (TFA)-acetonitrile (ACN) at 0.8 mL min(-1). The temperature of the column was maintained at 25°C. The excitation and emission wavelengths were set at 380 and 470 nm, respectively. The thiol derivatives were well separated in 19 min, and the total analysis time was 30 min. The established method was proved selective, specific and reproducible, and could be applicable to determine Cys, GSH and PC(2-6) and to evaluate their roles in detoxification mechanisms in Cd-treated Lolium perenne L. under ambient and elevated carbon dioxide (CO(2)). It was found that the total SH contents and proportions of thiols in roots and shoots were dependent on Cd concentration, whereas the total SH contents decreased and the proportions of thiols altered without significance at elevated CO(2) level. PMID:21561813

  11. Towards a better understanding of the generation of fructan structure diversity in plants: molecular and functional characterization of a sucrose:fructan 6-fructosyltransferase (6-SFT) cDNA from perennial ryegrass (Lolium perenne)

    PubMed Central

    Lasseur, Bertrand; Lothier, Jérémy; Wiemken, Andres; Van Laere, André; Morvan-Bertrand, Annette; den Ende, Wim Van; Prud'homme, Marie-Pascale

    2011-01-01

    The main storage compounds in Lolium perenne are fructans with prevailing β(2–6) linkages. A cDNA library of L. perenne was screened using Poa secunda sucrose:fructan 6-fructosyltransferase (6-SFT) as a probe. A full-length Lp6-SFT clone was isolated as shown by heterologous expression in Pichia pastoris. High levels of Lp6-SFT transcription were found in the growth zone of elongating leaves and in mature leaf sheaths where fructans are synthesized. Upon fructan synthesis induction, Lp6-SFT transcription was high in mature leaf blades but with no concomitant accumulation of fructans. In vitro studies with the recombinant Lp6-SFT protein showed that both 1-kestotriose and 6G-kestotriose acted as fructosyl acceptors, producing 1- and 6-kestotetraose (bifurcose) and 6G,6-kestotetraose, respectively. Interestingly, bifurcose formation ceased and 6G,6-kestotetraose was formed instead, when recombinant fructan:fructan 6G-fructosyltransferase (6G-FFT) of L. perenne was introduced in the enzyme assay with sucrose and 1-kestotriose as substrates. The remarkable absence of bifurcose in L. perenne tissues might be explained by a higher affinity of 6G-FFT, as compared with 6-SFT, for 1-kestotriose, which is the first fructan formed. Surprisingly, recombinant 6-SFT from Hordeum vulgare, a plant devoid of fructans with internal glucosyl residues, also produced 6G,6-kestotetraose from sucrose and 6G-kestotriose. In the presence of recombinant L. perenne 6G-FFT, it produced 6G,6-kestotetraose from 1-kestotriose and sucrose, like L. perenne 6-SFT. Thus, we demonstrate that the two 6-SFTs have close catalytic properties and that the distinct fructans formed in L. perenne and H. vulgare can be explained by the presence of 6G-FFT activity in L. perenne and its absence in H. vulgare. PMID:21196473

  12. [Yunnan population].

    PubMed

    1981-03-23

    In 1980, the population growth rate in Yunnan was reduced to 10.25/1000. Compared with 1979, the number of births was reduced by 152,000 persons. The population growth rate was reduced by 4.35/1000. Localities in which the population growth rate was below 10/1000 in 1980 include Kunming, Baoshan, Yuxi, Chuxiong, Dongchuan, Lijiang, Dali, and Honghe prefectures, autonomous prefectures and municipalities. This growth rate was also achieved in 69 counties, districts and towns as well as 665 communes. Some 66,500 couples throughout the province received 1-child certificates. In 1980, under the leadership of the party and government, the trade unions, CYL, women's federations, and public health departments paid attention to grasping planned parenthood work. PMID:12264026

  13. Population success.

    PubMed

    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

  14. Bioaccumulation of metals in ryegrass (Lolium perenne L.) following the application of lime stabilised, thermally dried and anaerobically digested sewage sludge.

    PubMed

    Healy, M G; Ryan, P C; Fenton, O; Peyton, D P; Wall, D P; Morrison, L

    2016-08-01

    The uptake and accumulation of metals in plants is a potential pathway for the transfer of environmental contaminants in the food chain, and poses potential health and environmental risks. In light of increased population growth and urbanisation, the safe disposal of sewage sludge, which can contain significant levels of toxic contaminants, remains an environmental challenge globally. The aims of this experiment were to apply municipal sludge, having undergone treatment by thermal drying, anaerobic digestion, and lime stabilisation, to permanent grassland in order to assess the bioaccumulation of metals (B, Al, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, As, Nb, Mo, Sb, Ba, W, Pb, Fe, Cd) by perennial ryegrass over a period of up to 18 weeks after application. The legislation currently prohibits use of grassland for fodder or grazing for at least three weeks after application of treated sewage sludge (biosolids). Five treatments were used: thermally dried (TD), anaerobically digested (AD) and lime stabilised (LS) sludge all from one wastewater treatment plant (WWTP), AD sludge from another WWTP, and a study control (grassland only, without application of biosolids). In general, there was no significant difference in metal content of the ryegrass between micro-plots that received treated municipal sludge and the control over the study duration. The metal content of the ryegrass was below the levels at which phytotoxicity occurs and below the maximum levels specified for animal feeds. PMID:27174047

  15. Population geography.

    PubMed

    Nash, A

    1994-03-01

    Population geographers are involved in contemporary policy issues, the production of quality work, and successful communication of research findings. This article reviewed some contributions population geographers have made to the understanding of the geographic impact of aging and the consequences of migration. Geographers have come late to the study of aging and have focused primarily on four main policy issues: 1) fertility decline, 2) housing demography, 3) aged patterns of housing and migration, and 4) government policy. Fertility decline research has highlighted information diffusion theories for fertility decline by researchers such as Zelinsky, Skeldon, and Noin. Changes in attitudes and the removal on constraints has been examined by Woods. Residential mobility studies have been the focus of researchers such as Gober, Moore, and Clark, and Myers. Regional labor markets and the movement of the "baby boom" through the life course have been examined by Miron, Plane and Rogerson, and Clout, who studied the empty nesters and the movement out of suburbia. Private residential housing has increased for the elderly in England and Wales (Hamnett and Mullings), and seasonal migration of Minnesotans results in lost sales revenues and high health and social costs for those too ill to travel (Craig). Geographers have not accomplished a significant thrust into the literature on demographic aging. Contributions to the transnational and international literature have resulted in internal migration studies by Clout on "counterurbanization" in northwestern industrial Europe, while Fielding, Baltensperger, Marchand and Scott, and Jones have examined the continuing rural-urban migration. The loss of urban population has been associated with inner city problems, the impact of labor supply and market demand, and the revenue and health care consequences in the work of Champion, Gibson, and Champion and Illeris, and Craig. Impacts are felt differently by geographic location, and

  16. Seasonal Abundance and Phenology of Oebalus pugnax (Hemiptera: Pentatomidae) on Graminaceous Hosts in the Delta Region of Mississippi.

    PubMed

    Awuni, G A; Gore, J; Cook, D; Musser, F; Bond, J

    2015-08-01

    The rice stink bug, Oebalus pugnax (F.), is a graminaceous feeder, and the most injurious insect pest of heading rice, Oryza sativa L., in the United States. Rice growers are aware of the economic importance of host grasses in O. pugnax abundance. However, the need for increased knowledge of host sequence relative to O. pugnax abundance is vital. Densities of O. pugnax on 15 graminaceous hosts were evaluated in the central Mississippi Delta from April through August in 2011 and 2012. Two cultivated and 13 wild host grasses were sampled using a sweep net. Overall, populations of O. pugnax were lower in 2012 than in 2011. Italian ryegrass, Lolium perenne L. ssp. multiflorum (Lambert), was the main host that supported O. pugnax survival and reproduction from overwintering to early summer. Echinochloa spp., Digitaria spp., and Eriochloa spp. maintained greater populations of O. pugnax in the summer. Browntop millet, Urochloa ramosa (L.) Nguyen, and broadleaf signalgrass, U. platyphylla (Munro ex C. Wright) R. D. Webster, were important for populations of O. pugnax populations immediately prior to overwintering. Host switching was also an important factor that contributed to O. pugnax abundance. The evolution of Italian ryegrass resistance to the broad spectrum herbicide glyphosate in the central Mississippi delta has become an important component of O. pugnax population dynamics because of its increased abundance in and around agricultural areas. Cultural control measures on host grasses before flowering could result in less use of insecticides, thereby reducing cost of rice production. PMID:26314038

  17. Transcriptomes of Lolium/Schedonorus/Festuca species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ESTs from normalized cDNA libraries of tall fescue with Neotyphodium coenophialum and meadow fescue with Epichloë festucae have been sequenced. The meadow fescue libraries were from RNA isolated from immature tillers of meadow fescue symbiotic with E. festucae, displaying normal inflorescences and ...

  18. Transcriptomes of Lolium/Schedonorus/Festuca Species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ESTs from normalized cDNA libraries of tall fescue with Neotyphodium coenophialum and meadow fescue with Epichloë festucae have been sequenced. The meadow fescue libraries were from RNA isolated from immature tillers of meadow fescue symbiotic with E. festucae, displaying normal inflorescences and ...

  19. Transcriptomes of Lolium/Schedonorus/Festuca species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Molecular tools for forage grasses are presently sparse. In order to make available these tools for the community, a large scale sequencing effort has been conducted. Roughly 140,000 cDNA clones from normalized libraries obtained from meadow fescue/Epichloe festucae inflorescences and stromata and t...

  20. Epigenetic rather than genetic factors may explain phenotypic divergence between coastal populations of diploid and tetraploid Limonium spp. (Plumbaginaceae) in Portugal

    PubMed Central

    2013-01-01

    Background The genus Limonium Miller comprises annual and perennial halophytes that can produce sexual and/or asexual seeds (apomixis). Genetic and epigenetic (DNA methylation) variation patterns were investigated in populations of three phenotypically similar putative sexual diploid species (L. nydeggeri, L. ovalifolium, L. lanceolatum), one sexual tetraploid species (L. vulgare) and two apomict tetraploid species thought to be related (L. dodartii, L. multiflorum). The extent of morphological differentiation between these species was assessed using ten diagnostic morphometric characters. Results A discriminant analysis using the morphometric variables reliably assigns individuals into their respective species groups. We found that only modest genetic and epigenetic differentiation was revealed between species by Methylation Sensitive Amplification Polymorphism (MSAP). However, whilst there was little separation possible between ploidy levels on the basis of genetic profiles, there was clear and pronounced interploidy discrimination on the basis of epigenetic profiles. Here we investigate the relative contribution of genetic and epigenetic factors in explaining the complex phenotypic variability seen in problematic taxonomic groups such as Limonium that operate both apomixis and sexual modes of reproduction. Conclusions Our results suggest that epigenetic variation might be one of the drivers of the phenotypic divergence between diploid and tetraploid taxa and discuss that intergenome silencing offers a plausible mechanistic explanation for the observed phenotypic divergence between these microspecies. These results also suggest that epigenetic profiling offer an additional tool to infer ploidy level in stored specimens and that stable epigenetic change may play an important role in apomict evolution and species recognition. PMID:24314092

  1. Phytoremediation of the polluted Waigang River and general survey on variation of phytoplankton population.

    PubMed

    Hu, Changwei; Ou, Yuxiong; Zhang, Dayi; Zhang, Hui; Yan, Cheng; Zhao, Yongjun; Zheng, Zheng

    2012-11-01

    The Waigang River, a major tributary of the Qinhuai River system, has suffered from long-standing pollution because of lack of management. Restoration was commenced in April 2006 to reduce pollutants and improve water quality. Four ecological areas and ten surface carriers were constructed for the culture of plants (mainly water hyacinth (Eichhornia crassipes) and ryegrass (Lolium perenne L.)) for phytoremediation. Chemical oxygen demand (COD), total suspended solids (TSS), total phosphorus, total nitrogen (TN), ammonia-nitrogen (NH(3)-N), water transparency, and variations in phytoplankton population were investigated to evaluate the effects of restoration. Over 36 months, TSS, COD, TN, and NH(3)-N levels decreased by 91.1, 55.3, 91.5, and 86.5 %, respectively. Transparency increased from 25 cm in 2006 to 165 cm in 2009. Improvements in water quality significantly enhanced the diversity of phytoplankton, which were harmed by pollution stress. Our results show that the water hyacinth and ryegrass cultured in the ecological areas and the surface carriers can be used to restore other heavily polluted rivers with conditions similar to those of the Waigang River, especially in the initial stages of restoration. PMID:22538826

  2. Impact of No-till Cover Cropping of Italian Ryegrass on Above and Below Ground Faunal Communities Inhabiting a Soybean Field with Emphasis on Soybean Cyst Nematodes

    PubMed Central

    Hooks, Cerruti R. R.; Wang, Koon-Hui; Meyer, Susan L. F.; Lekveishvili, Mariam; Hinds, Jermaine; Zobel, Emily; Rosario-Lebron, Armando; Lee-Bullock, Mason

    2011-01-01

    Two field trials were conducted between 2008 and 2010 in Maryland to evaluate the ability of an Italian ryegrass (IR) (Lolium multiflorum) cover crop to reduce populations of plant-parasitic nematodes while enhancing beneficial nematodes, soil mites and arthropods in the foliage of a no-till soybean (Glycine max) planting. Preplant treatments were: 1) previous year soybean stubble (SBS); and 2) herbicide-killed IR cover crop + previous year soybean stubble (referred to as IR). Heterodera glycines population densities were very low and no significant difference in population densities of H. glycines or Pratylenchus spp. were observed between IR and SBS. Planting of IR increased abundance of bacterivorous nematodes in 2009. A reverse trend was observed in 2010 where SBS had higher abundance of bacterivorous nematodes and nematode richness at the end of the cover cropping period. Italian ryegrass also did not affect insect pests on soybean foliage. However, greater populations of spiders were found on soybean foliage in IR treatments during both field trials. Potential causes of these findings are discussed. PMID:23430284

  3. Controlled release fertilizer increased phytoremediation of petroleum-contaminated sandy soil.

    PubMed

    Cartmill, Andrew D; Cartmill, Donita L; Alarcón, Alejandro

    2014-01-01

    A greenhouse experiment was conducted to determine the effect of the application of controlled release fertilizer [(CRF) 0, 4,6, or 8 kg m(-3)] on Lolium multiflorum Lam. survival and potential biodegradation of petroleum hydrocarbons (0, 3000, 6000, or 15000 mg kg(-1)) in sandy soil. Plant adaptation, growth, photosynthesis, total chlorophyll, and proline content as well as rhizosphere microbial population (culturable heterotrophic fungal and bacterial populations) and total petroleum hydrocarbon (TPH)-degradation were determined. Petroleum induced-toxicity resulted in reduced plant growth, photosynthesis, and nutrient status. Plant adaptation, growth, photosynthesis, and chlorophyll content were enhanced by the application of CRF in contaminated soil. Proline content showed limited use as a physiological indicator of petroleum induced-stress in plants. Bacterial and filamentous fungi populations were stimulated by the petroleum concentrations. Bacterial populations were stimulated by CRF application. At low petroleum contamination, CRF did not enhance TPH-degradation. However, petroleum degradation in the rhizosphere was enhanced by the application of medium rates of CRF, especially when plants were exposed to intermediate and high petroleum contamination. Application of CRF allowed plants to overcome the growth impairment induced by the presence of petroleum hydrocarbons in soils. PMID:24912225

  4. Effects of grass species and grass growth on atmospheric nitrogen deposition to a bog ecosystem surrounded by intensive agricultural land use

    PubMed Central

    Hurkuck, Miriam; Brümmer, Christian; Mohr, Karsten; Spott, Oliver; Well, Reinhard; Flessa, Heinz; Kutsch, Werner L

    2015-01-01

    We applied a 15N dilution technique called “Integrated Total Nitrogen Input” (ITNI) to quantify annual atmospheric N input into a peatland surrounded by intensive agricultural practices over a 2-year period. Grass species and grass growth effects on atmospheric N deposition were investigated using Lolium multiflorum and Eriophorum vaginatum and different levels of added N resulting in increased biomass production. Plant biomass production was positively correlated with atmospheric N uptake (up to 102.7 mg N pot−1) when using Lolium multiflorum. In contrast, atmospheric N deposition to Eriophorum vaginatum did not show a clear dependency to produced biomass and ranged from 81.9 to 138.2 mg N pot−1. Both species revealed a relationship between atmospheric N input and total biomass N contents. Airborne N deposition varied from about 24 to 55 kg N ha−1 yr−1. Partitioning of airborne N within the monitor system differed such that most of the deposited N was found in roots of Eriophorum vaginatum while the highest share was allocated in aboveground biomass of Lolium multiflorum. Compared to other approaches determining atmospheric N deposition, ITNI showed highest airborne N input and an up to fivefold exceedance of the ecosystem-specific critical load of 5–10 kg N ha−1 yr−1. PMID:26257870

  5. Effective population size of korean populations.

    PubMed

    Park, Leeyoung

    2014-12-01

    Recently, new methods have been developed for estimating the current and recent changes in effective population sizes. Based on the methods, the effective population sizes of Korean populations were estimated using data from the Korean Association Resource (KARE) project. The overall changes in the population sizes of the total populations were similar to CHB (Han Chinese in Beijing, China) and JPT (Japanese in Tokyo, Japan) of the HapMap project. There were no differences in past changes in population sizes with a comparison between an urban area and a rural area. Age-dependent current and recent effective population sizes represent the modern history of Korean populations, including the effects of World War II, the Korean War, and urbanization. The oldest age group showed that the population growth of Koreans had already been substantial at least since the end of the 19th century. PMID:25705160

  6. Effective population size and population subdivision in demographically structured populations.

    PubMed Central

    Laporte, Valérie; Charlesworth, Brian

    2002-01-01

    A fast-timescale approximation is applied to the coalescent process in a single population, which is demographically structured by sex and/or age. This provides a general expression for the probability that a pair of alleles sampled from the population coalesce in the previous time interval. The effective population size is defined as the reciprocal of twice the product of generation time and the coalescence probability. Biologically explicit formulas for effective population size with discrete generations and separate sexes are derived for a variety of different modes of inheritance. The method is also applied to a nuclear gene in a population of partially self-fertilizing hermaphrodites. The effects of population subdivision on a demographically structured population are analyzed, using a matrix of net rates of movement of genes between different local populations. This involves weighting the migration probabilities of individuals of a given age/sex class by the contribution of this class to the leading left eigenvector of the matrix describing the movements of genes between age/sex classes. The effects of sex-specific migration and nonrandom distributions of offspring number on levels of genetic variability and among-population differentiation are described for different modes of inheritance in an island model. Data on DNA sequence variability in human and plant populations are discussed in the light of the results. PMID:12242257

  7. Population control II: The population establishment today.

    PubMed

    Hartmann, B

    1997-01-01

    Although population assistance represents a relatively small share of official development assistance, it influences many other aspects of development planning. The organizations that comprise the population establishment have a common purpose--the reduction of population growth in the Third World--but they are not homogeneous and sometimes have conflicting goals and strategies. National governments, multilateral agencies, nongovernmental organizations, foundations, academic centers, and pressure groups all contribute to creating and sustaining what has become a virtual population control industry. Through scholarships, travel grants, awards, and favorable publicity, Third World elites have been encouraged to join the population establishment. The World Bank, the U.S. Agency for International Development, and the U.N. Fund for Population Activities have pursued explicit strategies for pressuring Third World governments to design and implement population policies, most recently in Africa. PMID:9285281

  8. Simulating Population Growth.

    ERIC Educational Resources Information Center

    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)

  9. Predicting Population Curves.

    ERIC Educational Resources Information Center

    Bunton, Matt

    2003-01-01

    Uses graphs to involve students in inquiry-based population investigations on the Wisconsin gray wolf. Requires students to predict future changes in the wolf population, carrying capacity, and deer population. (YDS)

  10. Education Vital Signs: Population.

    ERIC Educational Resources Information Center

    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. Combined effects between temporal heterogeneity of water supply, nutrient level, and population density on biomass of four broadly distributed herbaceous species.

    PubMed

    Hagiwara, Yousuke; Kachi, Naoki; Suzuki, Jun-Ichirou

    2012-01-01

    Temporal heterogeneity of water supply affects grassland community productivity and it can interact with nutrient level and intraspecific competition. To understand community responses, the responses of individual species to water heterogeneity must be evaluated while considering the interactions of this heterogeneity with nutrient levels and population density. We compared responses of four herbaceous species grown in monocultures to various combinations of water heterogeneity, nutrient level, and population density: two grasses (Cynodon dactylon and Lolium perenne), a forb (Artemisia princeps), and a legume (Trifolium repens). Treatment effects on shoot and root biomass were analyzed. In all four species, shoot biomass was larger under homogeneous than under heterogeneous water supply. Shoot responses of L. perenne tended to be greater at high nutrient levels. Although root biomass was also larger under homogeneous water supply, effects of water heterogeneity on root biomass were not significant in the grasses. Trifolium repens showed marked root responses, particularly at high population density. Although greater shoot and root growth under homogeneous water supply appears to be a general trend among herbaceous species, our results suggested differences among species could be found in the degree of response to water heterogeneity and its interactions with nutrient level and intraspecific competition. PMID:21327692

  12. Population Education Country Programmes.

    ERIC Educational Resources Information Center

    Population Education in Asia and the Pacific Newsletter, 1983

    1983-01-01

    Describes population programs in Afghanistan (nonformal, population education literacy program), India (problems in planning/managing population education in higher education), Indonesia (training for secondary/out-of-school inspectors), and Pakistan (integration of population education into school curricula). Programs in China, Korea, Vietnam,…

  13. Understanding Rural Population Loss.

    ERIC Educational Resources Information Center

    McGranahan, David A.; Beale, Calvin L.

    2002-01-01

    A quarter of nonmetro counties lost population in the 1990s, but population loss was not related to poverty rate or low educational levels, perhaps because low-skill workers can no longer expect better wages in urban areas. Population loss was related to low population density and remoteness (which decrease access to services), lack of natural…

  14. WHAT IS A POPULATION?

    EPA Science Inventory

    The word "population" has several meanings, a situation that can lead to confusion in risk assessments. A management goal "to protect wildlife populations," for example, might relate to populations as defined by population biologists, or it might mean simply to protect animals in...

  15. Human Population Problems

    ERIC Educational Resources Information Center

    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…

  16. Glyphosate-resistant weeds of South American cropping systems: an overview.

    PubMed

    Vila-Aiub, Martin M; Vidal, Ribas A; Balbi, Maria C; Gundel, Pedro E; Trucco, Frederico; Ghersa, Claudio M

    2008-04-01

    Herbicide resistance is an evolutionary event resulting from intense herbicide selection over genetically diverse weed populations. In South America, orchard, cereal and legume cropping systems show a strong dependence on glyphosate to control weeds. The goal of this report is to review the current knowledge on cases of evolved glyphosate-resistant weeds in South American agriculture. The first reports of glyphosate resistance include populations of highly diverse taxa (Lolium multiflorum Lam., Conyza bonariensis L., C. canadensis L.). In all instances, resistance evolution followed intense glyphosate use in fruit fields of Chile and Brazil. In fruit orchards from Colombia, Parthenium hysterophorus L. has shown the ability to withstand high glyphosate rates. The recent appearance of glyphosate-resistant Sorghum halepense L. and Euphorbia heterophylla L. in glyphosate-resistant soybean fields of Argentina and Brazil, respectively, is of major concern. The evolution of glyphosate resistance has clearly taken place in those agroecosystems where glyphosate exerts a strong and continuous selection pressure on weeds. The massive adoption of no-till practices together with the utilization of glyphosate-resistant soybean crops are factors encouraging increase in glyphosate use. This phenomenon has been more evident in Argentina and Brazil. The exclusive reliance on glyphosate as the main tool for weed management results in agroecosystems biologically more prone to glyphosate resistance evolution. PMID:18161884

  17. The Population Reference Bureau's Population Handbook.

    ERIC Educational Resources Information Center

    Haupt, Arthur; Kane, Thomas T.

    This handbook offers information on population dynamics. The population data resource is intended for use by journalists, policymakers, teachers, high school and college students, libraries, advertising agencies, and family planning groups. The document is presented in 12 sections. Section I introduces demography, explains the purpose and scope of…

  18. Glaucoma in Asian Populations

    MedlinePlus

    ... 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 ...

  19. Genetics and population history of Caucasus populations.

    PubMed

    Bulayeva, Kazima; Jorde, Lynn B; Ostler, Christopher; Watkins, Scott; Bulayev, Oleg; Harpending, Henry

    2003-12-01

    We describe aspects of genetic diversity in several ethnic populations of the Caucasus Mountains of Daghestan using mitochondrial DNA sequences and a sample of 100 polymorphic Alu insertion loci. The mitochondrial DNA (mtDNA) sequences are like those of Europe. Principal coordinates and nearest neighbor statistics show that there is little detectable structure in the distances among populations computed from mtDNA. The Alu frequencies of the Caucasus populations suggest that they have undergone more genetic drift than most other groups since the dispersal of modern humans. Genetic differences among these populations are not large; instead, they are of the same order as distances among populations of Europe. We compare two methods of inference about the demography of ancient colonizing populations from Africa, one based on conventional FST statistics and one based on mean Alu insertion frequencies. The two approaches agree reasonably well if we assume that there was demographic growth in Africa before the diaspora of ancestors of contemporary regional human groups outside Africa. PMID:15018034

  20. Planning for Growing Populations.

    ERIC Educational Resources Information Center

    Cassen, Robert, Ed.; Wolfson, Margaret, Ed.

    The basic needs and services that the vast masses of the population in developing countries must have to improve their quality of life are examined. Chapter 1 of nine chapters discusses implications of rapid population growth for social and economic planning. Rapid population growth in the developing countries is discussed in chapter 2. Food…

  1. Impact of Population Growth

    ERIC Educational Resources Information Center

    Ehrlich, Paul R.; Holdren, John P.

    1971-01-01

    Discusses the interrelated crises in population growth, natural resources, and environmental quality. Major problems include population control, redirection of technology, closed resource cycles, equitable opportunity distribution and prosperity. Population growth is regarded as causing a disportionate world-wide negative environmental impact.…

  2. Teaching about Population Issues.

    ERIC Educational Resources Information Center

    Otero, George G., Jr., Comp.

    This teaching guide on population issues contains 19 activities for students in grades 7-12. The objective is to analyze population issues that have resulted from human population dynamics. In this guide, four categories of activities are included: some are discussion starters, some provide factual data, some focus on thinking skills, and some are…

  3. Modeling Exponential Population Growth

    ERIC Educational Resources Information Center

    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…

  4. [Population Growth and Development].

    ERIC Educational Resources Information Center

    Clausen, A. W.

    Rapid population growth as a central development problem, the proper domain of government in reducing population growth, and effective measures which can be taken to reduce fertility are examined. Rapid population growth puts a brake on development because it exacerbates the difficult choice between higher consumption now and the investment needed…

  5. Controlling Population with Pollution

    ERIC Educational Resources Information Center

    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.

  6. [Prehistoric population studies].

    PubMed

    Posse, Z C

    1985-01-01

    Studies concerning prehistoric populations in the Americas are discussed. "A review is made of research conducted in America focusing...on indigenous populations prior to contacts with Europeans, and those which, employing archaeological and historical sources, seek to evaluate the population and establish depopulation indexes for the said societies." (SUMMARY IN ENG) PMID:12341861

  7. Populations, Teacher's Guide.

    ERIC Educational Resources Information Center

    Conard, David; Lawson, Chester A.

    This Teacher's Guide is designed for use with the Science Curriculum Improvement Study's (SCIS) unit Population. Populations is the third of a six-unit sequence of SCIS's Life Science Program for grades K-6. The Populations guide consists of activity outlines along with suggestions for guiding children's observation and manipulations of living…

  8. Teaching Population Geography.

    ERIC Educational Resources Information Center

    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…

  9. Population Education Country Programmes.

    ERIC Educational Resources Information Center

    Population Education in Asia and the Pacific Newsletter, 1985

    1985-01-01

    Discusses population education programs in China, India, Indonesia, Maldives, Nepal, Pakistan, Philippines, Sri Lanka, and Vietnam. Sri Lanka is developing audio-visual materials and integrating population education into secondary science and social studies curricula. Nepal is transmitting nonformal population education messages to adults through…

  10. Population Education in Baltimore.

    ERIC Educational Resources Information Center

    Cochran, Caroline S.; McCrea, Lester C.

    First in a series of six documents, this report describes the Urban Life-Population Education Institute (ULPEI) program which was designed to demonstrate population realities to Baltimore public schools so that teachers can introduce population studies into the school curriculum. The first part of the paper presents background information on the…

  11. Population: A Lively Introduction.

    ERIC Educational Resources Information Center

    McFalls, Joseph A., Jr.

    1991-01-01

    The study of demography must begin with an understanding of the three sources of population changes: fertility, mortality, and migration. This paper leads prospective demographers--or anyone interested in population--through the dynamics of these three variables, introducing them to the forces that cause populations to grow or decline, and that…

  12. Teaching about Population Growth.

    ERIC Educational Resources Information Center

    Otero, George G., Jr., Comp.

    This teaching guide contains 20 activities on population growth for students in grades 6-12. The purpose is to help students gain the skills, knowledge, and understanding of population dynamics so that they can make rational decisions and take responsible action regarding population matters and public policy. Activities are organized around the…

  13. Nutrients Can Enhance the Abundance and Expression of Alkane Hydroxylase CYP153 Gene in the Rhizosphere of Ryegrass Planted in Hydrocarbon-Polluted Soil

    PubMed Central

    Arslan, Muhammad; Afzal, Muhammad; Amin, Imran; Iqbal, Samina; Khan, Qaiser M.

    2014-01-01

    Plant-bacteria partnership is a promising strategy for the remediation of soil and water polluted with hydrocarbons. However, the limitation of major nutrients (N, P and K) in soil affects the survival and metabolic activity of plant associated bacteria. The objective of this study was to explore the effects of nutrients on survival and metabolic activity of an alkane degrading rhizo-bacterium. Annual ryegrass (Lolium multiflorum) was grown in diesel-contaminated soil and inoculated with an alkane degrading bacterium, Pantoea sp. strain BTRH79, in greenhouse experiments. Two levels of nutrients were applied and plant growth, hydrocarbon removal, and gene abundance and expression were determined after 100 days of sowing of ryegrass. Results obtained from these experiments showed that the bacterial inoculation improved plant growth and hydrocarbon degradation and these were further enhanced by nutrients application. Maximum plant biomass production and hydrocarbon mineralization was observed by the combined use of inoculum and higher level of nutrients. The presence of nutrients in soil enhanced the colonization and metabolic activity of the inoculated bacterium in the rhizosphere. The abundance and expression of CYP153 gene in the rhizosphere of ryegrass was found to be directly associated with the level of applied nutrients. Enhanced hydrocarbon degradation was associated with the population of the inoculum bacterium, the abundance and expression of CYP153 gene in the rhizosphere of ryegrass. It is thus concluded that the combination between vegetation, inoculation with pollutant-degrading bacteria and nutrients amendment was an efficient approach to reduce hydrocarbon contamination. PMID:25360680

  14. Early vs. asymptotic growth responses of herbaceous plants to elevated CO[sub 2

    SciTech Connect

    Thomas, S.C.; Jasienski, M.; Bazzaz, F.A. . Dept. of Organismic and Evolutionary Biology)

    1999-07-01

    Although many studies have examined the effects of elevated carbon dioxide on plant growth,'' the dynamics of growth involve at least two parameters, namely, an early rate of exponential size increase and an asymptotic size reached late in plant ontogeny. The common practice of quantifying CO[sub 2] responses as a single response ratio thus obscures two qualitatively distinct kinds of effects. The present experiment examines effects of elevated CO[sub 2] on both early and asymptotic growth parameters in eight C[sub 3] herbaceous plant species (Abutilon theophrasti, Cassia obtusifolia, Plantago major, Rumex crispus, Taraxacum officinale, Dactylis glomerata, Lolium multiflorum, and Panicum dichotomoflorum). Plants were grown for 118--172 d in a factorial design of CO[sub 2] (350 and 700 [micro]L/L) and plant density (individually grown vs. high-density monocultures) under edaphic conditions approximating those of coastal areas in Massachusetts. For Abutilon theophrasti, intraspecific patterns of plant response were also assessed using eight genotypes randomly sampled from a natural population and propagated as inbred lines.

  15. Population and Environment

    PubMed Central

    de Sherbinin, Alex; Carr, David; Cassels, Susan; Jiang, Leiwen

    2009-01-01

    The interactions between human population dynamics and the environment have often been viewed mechanistically. This review elucidates the complexities and contextual specificities of population-environment relationships in a number of domains. It explores the ways in which demographers and other social scientists have sought to understand the relationships among a full range of population dynamics (e.g., population size, growth, density, age and sex composition, migration, urbanization, vital rates) and environmental changes. The chapter briefly reviews a number of the theories for understanding population and the environment and then proceeds to provide a state-of-the-art review of studies that have examined population dynamics and their relationship to five environmental issue areas. The review concludes by relating population-environment research to emerging work on human-environment systems. PMID:20011237

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

    PubMed

    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

  17. Population information resources.

    PubMed

    Pasquariella, S K

    1984-12-01

    This article describes print and computerized services that are dedicated to bibliographic coverage of 1 or more areas of population studies. Major printed bibliographic information resources for population material include: ADOPT, DOCPAL Resumenes sobre Poblacion en America Latina, PIDSA Abstracts, Population Index and Review of Population Reviews. ADOPT is an annotated computer-aided current-awareness bibliographic journal which has been published monthly since January 1975 by the Regional Population Information Center of the Economic and Social Commission for Asia and the Pacific (ESCAP). DOCPAL Resumenes is a computer-produced biannual collection of abstracts containing indexes and between 600 and 700 summaries of both published and unpublished population documents. PIDSA is intended to make available documentary information about population matters in sub-Saharan Africa. Population Index, 1 of the oldest and most definitive bibliographies in the demography field, is international in scope and is arranged as a classified and annotated bibliography of monographs, journal articles and 2ndary source material relevant to all aspects of demography. Review of Population Reviews, published 4 times a year, are annotated bibliographies containing summaries of articles that have been published in 83 periodicals in 37 countries. Cited articles are assigned subject-heading descriptors from the Population Multilingual Thesaurus. Major computerized information resources are: DOCPAL, DOCPOP, EBIS/POPFILE, MANPINS, POPLINE and POPULATION BIBLIOGRAPHY. DOCPAL was established to assist Latin Ameran countries in the collection, storage, processing and retrieval of population documents about Latin America. DOCPAL contains over 19,000 bibliographic citations. DOCPOP was established as the 1st Latin American national computerized population documentation system for Brazilian material. POPLINE is a computerized retrieval service cooperatively produced in the US which covers the

  18. Population and development.

    PubMed

    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

  19. Population policies in perspective.

    PubMed

    Duden, B

    1992-01-01

    This paper consists of excerpts of the author's population chapter in The Development Dictionary: A Guide to Knowledge as Power. The author opens by noting the general tendency for people to fear and connote overpopulation when exposed to the term population. Population evokes emotional, value-laden paranoia among populations of industrialized countries, who fear that the rapid population growth of developing countries will lead to a world dominated by individuals of yellow and brown skin complexion. Populations grow, consume, pollute, need, demand, and are entitled. They are objects which can be acted upon, controlled, developed, and limited. As such, the author presents her view of how population has been transformed over 40 years of development discourse and the social realities engendered by its use. She contends that the term has become a tool for the verbal extermination of people. The discussion is presented in brief sections under the following headings: how people became populations, birth control for development, and population control for survival. PMID:12286349

  20. Equine palmar artery, palmar vein and uterine artery express different populations of vasoactive biogenic amine receptors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Consumption of endophyte-infected (Neotyphodium coenophialum) tall fescue (Lolium arundinaceum) seed by horses causes constriction of the palmar artery (PA), palmar vein (PV) and reduced blood flow to the corpus luteum that can be measured in vivo by Doppler ultrasonography. In addition, myograph st...

  1. Population education resources.

    PubMed

    Larkin, R P; Peters, G L

    1981-01-01

    This article provides information on those population education materials and services which are available from the Population Reference Bureau (PRB) and explores their usefulness in secondary school and college environments. PRB data sheets are a most useful source of information. Demographic and socioeconomic information (birth and death rates, natural increase, population doubling times, projections for the year 2000, life expectancies, per capita gross national product, etc.) are included. The World's Women Data Sheet is a special publication issued to mark the midway point of the UN Decade for Women. 161 countries are included with information on demographic, health, employment, and educational status of women. There is a nominal cost for these data sheets. To help students learn about population dynamics and world patterns of population, mapping exercises can be developed. The Population Bulletin is published 6 times/year and each issue concentrates on specific aspects of population. The 28 bulletins which have been published since January 1976 are listed. The PRB Chart Series is a multicolor graphic presentation of topical issues in population and development trends worldwide. A total of 26 charts in 4 series have been produced and cover such topics as world population growth, urbanization, world energy consumption, age structure in the U.S., and adolescent pregnancy in the U.S. This material is best used with high school students. A monthly international population news magazine called Intercom is desinged to inform about worldwide trends and activities in population and family planning. It is published in both English and Spanish and is a useful source of current information in capsulized form. For population educators there is the bimonthly newsletter Interchange. PRB's teaching-learning modules are valuable publications for teachers. Thus far there are 9, each of which is a self-contained unit with classroom activities for junior high to college students

  2. Allelic Variation in the Perennial Ryegrass FLOWERING LOCUS T Gene Is Associated with Changes in Flowering Time across a Range of Populations1[W

    PubMed Central

    Skøt, Leif; Sanderson, Ruth; Thomas, Ann; Skøt, Kirsten; Thorogood, Danny; Latypova, Galina; Asp, Torben; Armstead, Ian

    2011-01-01

    The Arabidopsis (Arabidopsis thaliana) FLOWERING LOCUS T (FT) gene and its orthologs in other plant species (e.g. rice [Oryza sativa] OsFTL2/Hd3a) have an established role in the photoperiodic induction of flowering response. The genomic and phenotypic variations associated with the perennial ryegrass (Lolium perenne) ortholog of FT, designated LpFT3, was assessed in a diverse collection of nine European germplasm populations, which together constituted an association panel of 864 plants. Sequencing and genotyping of a series of amplicons derived from the nine populations, containing the complete exon and intron sequences as well as 5′ and 3′ noncoding sequences of LpFT3, identified a total of seven haplotypes. Genotyping assays designed to detect the genomic variation showed that three haplotypes were present in approximately equal proportions and represented 84% of the total, with a fourth representing a further 11%. Of the three major haplotypes, two were predicted to code for identical protein products and the third contained two amino acid substitutions. Association analysis using either a mixed model with a relationship matrix to correct for population structure and relatedness or structured association with further correction using genomic control indicated significant associations between LpFT3 and variation in flowering time. These associations were corroborated in a validation population segregating for the same major alleles. The most “diagnostic” region of genomic variation was situated 5′ of the coding sequence. Analysis of this region identified that the interhaplotype variation was closely associated with sequence motifs that were apparently conserved in the 5′ region of orthologs of LpFT3 from other plant species. These may represent cis-regulatory elements involved in influencing the expression of this gene. PMID:21115808

  3. Populations, Teacher's Guide.

    ERIC Educational Resources Information Center

    California Univ., Berkeley. Science Curriculum Improvement Study.

    The Science Curriculum Improvement Study has developed this teacher's guide to "Populations," the third part of a six-unit life science curriculum sequence. The six basic units, emphasizing organism-environment interactions, are organisms, life cycles, populations, environments, communities, and ecosystems; and they make use of scientific and…

  4. World Population Crisis.

    ERIC Educational Resources Information Center

    Ehrlich, Paul R.; Ehrlich, Anne H.

    1986-01-01

    Rapid population growth, rising competition for resources, and increasing environmental deterioration are intertwined factors in the human predicament that feed political tensions and conflicts of the late twentieth century. Outlines dimensions of this predicament (including data on population, growth, military spending, quality of life, and…

  5. Measuring Populations, Part 2.

    ERIC Educational Resources Information Center

    Dillner, Harry

    This autoinstructional lesson dealing with the study of population growth is the second part of a two-part sequence. This is a learning activity for high school students who have completed Part 1 of "Measuring Populations" and are capable of using a microscope and of preparing slides to be observed. The behavioral objectives, both general and…

  6. The Population Threat

    ERIC Educational Resources Information Center

    McNamara, Robert S.

    1969-01-01

    In an address delivered at the University of Notre Dame, May 1969, Secretary McNamara discussed the threat of unmanageable population pressure which is undervalued and misunderstood by the general public. Unrestricted population growth will have catastrophic consequences unless it is dealt with rapidly and rationally. Copies from: Office of…

  7. Junior Biology, Populations.

    ERIC Educational Resources Information Center

    Hamilton City Board of Education (Ontario).

    Twenty-one studies related to populations are included in this student manual for a junior high school biology course. Each activity or study provides questions, diagrams, experiments, and/or descriptive material to which the student must respond. Population studies pertain to individual plants and animals, their physical environments, reactions…

  8. Population. Headline Series.

    ERIC Educational Resources Information Center

    Oppenheimer, Valerie K.

    Useful as background reading or secondary classroom material, this pamphlet reviews several dimensions of world population growth and control. The first of seven chapters, World Population Growth: Past, Present and Future, discusses some of the reasons for the greatly accelerated growth since 1950, and points out that even significantly rapid…

  9. Teaching Notes on Population.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Center for International Programs and Cooperative Services.

    This newsletter is designed to serve as a clearinghouse for the exchange of ideas and information on new strategies of teaching and instructional resources about population in colleges and universities. The first article discusses some of the contemporary problems faced in teaching population studies to undergraduates. The second article outlines…

  10. Population Trends and Prospects.

    ERIC Educational Resources Information Center

    Mauldin, W. Parker

    1980-01-01

    Future trends in population are described as they relate to developed and developing nations. It is suggested that for the next 20 years there will be a decrease in population growth rates for all areas of the world except Africa. (Author/SA)

  11. The Population Activist's Handbook.

    ERIC Educational Resources Information Center

    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…

  12. Mentoring Special Populations

    ERIC Educational Resources Information Center

    Whitfield, Keith E.; Edwards, Christopher L.

    2011-01-01

    Mentorship is critical for career development. Members of special populations are at increased risk of information shortfalls and advice that is not framed with cultural sensitivity. Special knowledge and skills are needed to successfully mentor members of ethnic minority and other special populations. Midlevel and senior scientists need…

  13. Diversity of Poissonian populations

    NASA Astrophysics Data System (ADS)

    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.

  14. Quantifying Health Across Populations.

    PubMed

    Kershnar, Stephen

    2016-07-01

    In this article, I argue that as a theoretical matter, a population's health-level is best quantified via averagism. Averagism asserts that the health of a population is the average of members' health-levels. This model is better because it does not fall prey to a number of objections, including the repugnant conclusion, and because it is not arbitrary. I also argue that as a practical matter, population health-levels are best quantified via totalism. Totalism asserts that the health of a population is the sum of members' health-levels. Totalism is better here because it fits better with cost-benefit analysis and such an analysis is the best practical way to value healthcare outcomes. The two results are compatible because the theoretical and practical need not always align, whether in general or in the context of population health. PMID:26766584

  15. Shifts that divide population

    NASA Astrophysics Data System (ADS)

    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. Understanding population health terminology.

    PubMed

    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, and sociology. Nonetheless, thinking and communicating clearly about population health concepts are essential for public and private policymakers to improve the population's health and reduce disparities. This article defines and discusses many of the terms and concepts characterizing this emerging field. PMID:17319809

  17. Cairo: repackaging population control.

    PubMed

    Simons, H

    1995-01-01

    Aid agencies, charities, and other nongovernmental organizations once denounced population control programs as racist interference in the third world. Yet, at the United Nations Conference on Population and Development in Cairo last September, these same organizations endorsed very similar ideas. The U.N. can now claim that even its fiercest critics not only have muted their criticism of population control programs but now positively endorse them. Over the last 30 years, population control has been consciously repackaged by the U.S. establishment. The image of population control has changed from being overtly anti-third world to being about giving the people of the third world--especially women--basic rights in family planning. Wrapped up in the language of women's empowerment and environmentalism, the establishment's old arguments about there being too many nonwhite babies in the world, have, unfortunately, won the day. PMID:7591381

  18. Global population growth.

    PubMed

    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

  19. The population threat.

    PubMed

    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. Hanford Area 2000 Population

    SciTech Connect

    Elliott, Douglas B.; Scott, Michael J.; Antonio, Ernest J.; Rhoads, Kathleen

    2004-05-28

    This report was prepared for the U.S. Department of Energy (DOE) Richland Operations Office, Surface Environmental Surveillance Project, to provide demographic data required for ongoing environmental assessments and safety analyses at the DOE Hanford Site near Richland, Washington. This document includes 2000 Census estimates for the resident population within an 80-kilometer (50-mile) radius of the Hanford Site. Population distributions are reported relative to five reference points centered on meteorological stations within major operating areas of the Hanford Site - the 100 F, 100 K, 200, 300, and 400 Areas. These data are presented in both graphical and tabular format, and are provided for total populations residing within 80 km (50 mi) of the reference points, as well as for Native American, Hispanic and Latino, total minority, and low-income populations.

  1. AMPHIBIAN POPULATION DYNAMICS

    EPA Science Inventory

    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...

  2. Parallel grid population

    DOEpatents

    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.

  3. Population genetics of Lithuanians.

    PubMed

    Ku inskas, V

    2001-01-01

    The primary objective of this article was to overview the present-day knowledge on genetic features of the Lithuanian population. Genetic differentiation within the Lithuanian population and the relationship between Lithuanians and other European populations was analysed by means of blood groups, serum protein polymorphisms and DNA markers including mtDNA. The results of the research have shown small differences between present-day Lithuanian ethnolinguistic groups, which probably go back to the prehistoric Baltic tribal structure. The Baltic peoples show a mixture of eastern and western genetic traits, e.g. a high frequency of the blood group B combined with a very high frequency of the Rh-negative blood group. Studies of the Baltic 'tribal gene' LWb indicate the presence of a considerable Baltic admixture in the neighbouring Finno-Ugric and Slavic populations. PMID:11201326

  4. Population Education. Awareness Activities.

    ERIC Educational Resources Information Center

    Brouse, Deborah E.

    1990-01-01

    Described are awareness activities that deal with human population growth, resources, and the environment. Activities include simulations, mathematical exercises, and discussions of the topic. Specific examples of what individuals can do to help are listed. (KR)

  5. Modeling Honey Bee Populations

    PubMed Central

    Torres, David J.; Ricoy, Ulises M.; Roybal, Shanae

    2015-01-01

    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. PMID:26148010

  6. Food for tomorrow's population.

    PubMed

    Hugo, G

    1983-06-01

    This discussion outlines and clarifies the dimensions of the world's current food-population balance and examines likely future changes in this balance over the next 20 years. The 1st section summarizes the contemporary world demographic situation in the early 1980s, focusing on regional differences in patterns of population growth and the significant food shortages in the developing countries. A subsequent section considers the outlook for population growth up to the year 2000 with particular reference to the most recent UN population projects. The discussion of food production and supply includes some specific comments on the situation in Indonesia. The world's population in 1983 has been estimated at 4677 million. It will reach 5 billion in the next 5 years. The countries which can least afford it are growing the fastest. These countries will account for 79% of the world's population in 2000 and 83% by 2020. Fertility in the less developed countries (LDCs) is twice that of more developed countries, with women in the former group having an average of around 4.5 children and in the latter, 1.9. The substantial declines in fertility in many countries are not fully reflected in declines in population growth and natural increase rates. This is because of major improvements which have occurred in mortality. During recent decades there has been a marked increase in world food production. In the developed countries increases in food production have continued at more than twice those for population, but this was not the case in the less developed countries where the margin narrowed during the 1950s and 1960s until in the early 1970s population was increasing at a slightly faster rate overall than was food production. Food crisis situations continue to occur with disturbing frequency in several regions. Seasonal, regional, and national variations in food shortages are not the only dimensions to food-population imbalances. Within nations there is inequality in access to

  7. Pharmacogenetics in Jewish populations

    PubMed Central

    Yang, Yao; Peter, Inga; Scott, Stuart A.

    2014-01-01

    Spanning over 2000 years, the Jewish population has a long history of migration, population bottlenecks, expansions, and geographical isolation, which has resulted in a unique genetic architecture among the Jewish people. As such, many Mendelian disease genes and founder mutations for autosomal recessive diseases have been discovered in several Jewish groups, which have prompted recent genomic studies in the Jewish population on common disease susceptibility and other complex traits. Although few studies on the genetic determinants of drug response variability have been reported in the Jewish population, a number of unique pharmacogenetic variants have been discovered that are more common in Jewish populations than in other major racial groups. Notable examples identified in the Ashkenazi Jewish (AJ) population include the vitamin K epoxide reductase complex subunit 1 (VKORC1) c.106G>T (p.D36Y) variant associated with high warfarin dosing requirements and the recently reported cytochrome P450 2C19 (CYP2C19) allele, CYP2C19*4B, that harbors both loss-of-function [*4 (c.1A>G)] and increased-function [*17 (c.−806C>T)] variants on the same haplotype. These data are encouraging in that like other ethnicities and subpopulations, the Jewish population likely harbors numerous pharmacogenetic variants that are uncommon or absent in other larger racial groups and ethnicities. In addition to unique variants, common multi-ethnic variants in key drug metabolism genes (e.g., ABCB1, CYP2C8, CYP2C9, CYP2C19, CYP2D6, NAT2) have also been detected in the AJ and other Jewish groups. This review aims to summarize the currently available pharmacogenetics literature and discuss future directions for related research with this unique population. PMID:24867283

  8. Extinction of oscillating populations.

    PubMed

    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

  9. Extinction of oscillating populations

    NASA Astrophysics Data System (ADS)

    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.

  10. [Population and food scarcity].

    PubMed

    Castro, E S

    1995-07-01

    Rapid population growth and increasing industrialization threaten to exhaust the world's natural resources, while the air, water, and soil are contaminated by wastes. Efforts to modify processes endangering man's survival are merely local palliatives. World population increased by 2 billion in the past 10 years. El Salvador's population is growing at 2% annually and now exceeds 5 million. These facts are well known, but the average person does not feel personally affected by them, trusting in scientific and technological progress to solve problems. The reality is that 2/3 of the world's people are vulnerable to hunger. Technological advances in agriculture have been outpaced by rapid population growth. Droughts and other climatic disturbances lead to hunger, and lost harvests constitute calamities. El Salvador's ecological situation is critical, with widespread degradation of agricultural lands. Thousands of hectares are lost each year. The high cost of basic foods is due to the collapse of agricultural production, itself a result of poor planning. El Salvador has become an importer of many essential foodstuffs. Experts have predicted that rapid population growth will soon mean that the country is no longer able to produce all the food it needs. Campaigns for responsible parenthood are needed to slow population growth. Couples should decide how many children to have based on their ability to support and educate them. The government should adopt a realistic position and encourage responsible parenthood, with free medical advice and family planning services for those desiring to avoid pregnancy. PMID:12179419

  11. Population growth and consumption.

    PubMed

    Chalkley, K

    1997-04-01

    The relationship between population growth, resource consumption, and environmental degradation is complex. The rise in "greenhouse gases" that will cause climatic change is clearly due to human activity, and pollutants are often concentrated in densely populated areas. However, even an area with a negative population growth, such as Russia, can experience severe environmental degradation due to poor management. Consumption patterns have the most effect on ozone depletion, while population growth threatens biodiversity of and within species through the destruction of ecosystems. Migration joins population growth and social factors, such as land inequality, as major causes of deforestation, and global demand for water is expected to increase faster than the rate of population growth. Coastal development and over-fishing threaten to deplete the oceans, while soil quality is threatened by inappropriate land use. Estimates of the earth's carrying capacity range from less than 3 billion to more than 44 billion people, indicating how difficult it is to assess this figure. Development efforts throughout the world may lead to human gains that will ultimately be negated by environmental losses. These factors have led to growing support for environmentally sustainable development. PMID:12319715

  12. Population and human health.

    PubMed

    Hefnawi, F I; Ahmed, W

    1982-01-01

    The nature, proportions, causes, effects and cures of the Egyptian population crisis are analyzed. If the world population growth rate of 2% continues by the year 2000 a population of 6.5 billion can be expected. By 2115 the world population will have doubled. The greatest increase in population is made by developing countries, e.g. Egypt's population will double in 25 years, Turkey's in 26 years, and Algeria's in 21 years. National health goals become increasingly difficult to achieve under these conditions. For overpopulated countries the options of migration, resource transfer, and fertility control have both positive and negative effects. For Egypt, migration of medical manpower is a major factor responsible for low health standards. Technology transferred from developed countries to assist overpopulated developing countries to increase production of all resources is a slow procedure. Fertility control will slow population growth, reduce maternal morbidity, create smaller families which may result in better psychological family health and therefore better level of job performance. It will also permit women to participate in the work force more easily and earn independent incomes. The effects of health improvement have also been positive and negative in Egypt. The Egyptian population is still growing at a rate .3% higher than the world rate. This situation has resulted from a decline in the death rate rather than in an increase in fertility. The death rate dropped from 32.9 in 1937 to 26.8 in 1947 to 15.8 in 1967. Fertility is close to 5.5 which is no higher than the world average. The drop in death rattes is due to better sanitation, extension of medical services, immunization campaigns, expansiion of health education and greater availability of foo. Reduction of morbidity coupled with health improvement is hoped to foster increased acceptance of fertility control, increased population attention to and acceptance of fertility counseling and increased funding

  13. CITIES WITH 1990 POPULATION TOTALS AND 1999 POPULATION ESTIMATIONS

    EPA Science Inventory

    Point locations represent cities with 1990 Census population totals and 1999 Census population estimates. Cities represent Census Designated Place (CDP) as classified by the US Bureau of the Census. CDP comprise densely settled concentrations of population that are identifiable...

  14. The Population Multilingual Thesaurus.

    PubMed

    1982-04-01

    The idea of a multilingual thesaurus to facilitate indexing and retrieval of population information came about when the UN Population Commission expressed interest, in 1973, in computerizing demographic information along the lines developed by UNESCO in the social sciences; it was recommended that the Population Division of the UN Secretariat collaborate with the Committee for International Cooperation in National Research in Demography, with financial support from UNFPA. Work was begun in 1975 by a group of experts with a diversity of interests encompassing demography, population studies, and family planning. The Institut National d'Etudes Demographiques (INED) made its computer equipment available to the project. The resulting Population Multilingual Thesaurus (PMT) was published in August 1979 in English, Spanish, and French. The PMT is an important tool for documentation units and essential for the effective operation of the Population Information Network. Efforts were made to include all terminology pertinent to analysis of demographic and socioeconomic information, and relevant to problems and characteristics of differing geographical areas. Attention was given to compatability with other relevant vocabularies, in particular the Macrothesaurus for Information Processing in the Field of Economic and Social Development published by OECD. Recommendations and guidelines from a POPIN Working Group on the Management of the PMT which met in March 1982 are presented under the following headings: harmonization (PMT and Macrothesaurus; PMT and specifically population oriented thesauri); geographic names; possible expansion; reporting additional terms; deletion of unnecessary terms; priorities in thesaurus related activities (maintenance of PMT given priority over development of micro thesauri). The role of INED in the maintenance of the PMT through electronic data processing is described, including the modules used for online management. PMID:12312008

  15. Population, science, and technology.

    PubMed

    1979-08-01

    In the past 10 years, concepts of population and its determinants and consequences have broadened. Adoption of the World Population Plan of Action by 135 governments in 1974 demonstrated that consensus had been achieved on the role of population in the context of development; it was no longer popularly viewed as eternal to the process--it had become the focal point of development. The population session of a Colloquium to be held in Vienna in August will seek, out of a spirit of concern for "humanity in technology" to describe the current demographic scene and identify the issues most in need of attention. The major challenges of the 1980s appear to be the spatial distribution of population; the fertility patterns of the new generation of youth; access to educational and training opportunities; the status of women; and community responsibility to the individual. The scientific and technological community will be examining these and related issues and looking for new answers to another "when and how?" PMID:12335929

  16. Pharmacogenomics in admixed populations.

    PubMed

    Suarez-Kurtz, Guilherme

    2005-04-01

    Personalized drug therapy proffered by pharmacogenomics must be based on the recognition of inherent genetic individuality, rather than relying on inter-ethnic differences in the frequency of polymorphisms that affect the pharmacokinetics and targets of drugs. This is particularly significant in admixed populations, in which the substructure created by inter-ethnic crosses further increases the fluidity of racial and/or ethnic labels. Inter-ethnic admixture is either common or increasing quickly in many, if not most, populations, and so extrapolation on a global scale of pharmacogenomic data from well-defined ethnic groups is plagued with uncertainty. To impact positively on global health, pharmacogenomics must broaden its scope of investigation with respect to both target and population diversity, and avoid the risk of contributing to the creation of a genomics divide between regions and nations. In this review, I examine the challenges and advantages of studying pharmacogenomics in admixed populations, drawing examples mainly from the trihybrid populations of the Americas. PMID:15808344

  17. Marketing and population problems.

    PubMed

    Farley, J U; Leavitt, H J

    1971-07-01

    There are many elements in population programs that are more familiar to marketing men than to some population experts. Advertising is essential to reach the target population, and advertising evaluation techniques (e.g., surrogate indexes or audience measures) might be useful for evaluating both population information activities and the import of the entire program. Fundamental research on basid demand for fertility control is needed and a marketer's experience with planning and evaluating test markets can be useful in assessing potential selling targets and evaluating alternative promotional and distributional strategies. Special family planning clinics have certain disadvantages: expensive and scarce personnel are needed; red tape may be present; the network is based on the assumption that the client is willing to travel relatively great distances repeatedly; and clinics lack anonymity which may scare potential acceptors away. Most developing cultures have an intensively functioning distribution structure which delivers basic commodities to the most remote areas, providing relatively anonymous outlets that are physically close to the customs. Materials requiring a prescription might be distributed in exchange for script issued at and ultimately redeemed by clinics, this requiring only an occasional visit to a clinic. Mail-order service can be used to supplement a clinic's distribution of some contraceptives. It should be remembered that population administrators often have an antipathetic view toward business and marketing and "suspect" the profit motive. PMID:12276119

  18. Distance Learning for Special Populations

    ERIC Educational Resources Information Center

    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…

  19. Constructing populations in biobanking.

    PubMed

    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

  20. Thermodynamics and Human Population

    NASA Astrophysics Data System (ADS)

    Cordry, Sean M.

    2010-09-01

    This paper discusses a Fermi-problem exercise through which I take students in several of my college courses. Students work in teams, determining the average daily Caloric needs per person. Then they use insolation values to determine the size of a collection area needed to absorb the previously determined daily energy requirements. Adjustments to the size of the collection area are made based on energy absorption per biological trophic level, as well as the consideration that most diets are a mixture of plant- and animal-derived elements. Finally, using the total amount of farmland available on the planet, students calculate a maximum population value. Although the maximum population values derived herewith should not be considered authoritative, the exercise has three beneficial purposes: 1) a chance to talk about the modeling process and extrapolations, 2) an unexpected application of physics to social contexts, and 3) raising student awareness of population and energy issues.

  1. Population and Climate Change

    NASA Astrophysics Data System (ADS)

    O'Neill, Brian C.; Landis MacKellar, F.; Lutz, Wolfgang

    2000-11-01

    Population and Climate Change provides the first systematic in-depth treatment of links between two major themes of the 21st century: population growth (and associated demographic trends such as aging) and climate change. It is written by a multidisciplinary team of authors from the International Institute for Applied Systems Analysis who integrate both natural science and social science perspectives in a way that is comprehensible to members of both communities. The book will be of primary interest to researchers in the fields of climate change, demography, and economics. It will also be useful to policy-makers and NGOs dealing with issues of population dynamics and climate change, and to teachers and students in courses such as environmental studies, demography, climatology, economics, earth systems science, and international relations.

  2. Population and development.

    PubMed

    Pavlik, Z

    1995-01-01

    During the Paleolithic period, 10,000-100,000 people lived on the earth; their number exceeded 1 million at the beginning of the Neolithic period, reached 10 million during the Bronze Age, 100 million at the beginning of the Iron Age, 1 billion at the beginning of the 19th century, and 5.7 billion in 1995. The estimated global population will be 10 billion by the middle of the 21st century and is expected to stabilize at around 10-12 billion subsequently. Increased agricultural production helped bring about greater numbers of humanity and the advancement of society with a developing social hierarchy, although life expectancy was low at 22-28 years. In Europe, the Renaissance gradually evolved into the Industrial Revolution, and a demographic revolution accompanied this process. In some countries, population size increased more than five times. Eventually, mortality and fertility levels decreased and life expectancy increased. In Western civilization, increased individualism, secularization, compulsory school attendance, decreased agricultural population, emancipation of women, increased costs of raising children, and social and economic progress ensued. All this was preceded by 18th century conditions, when, in England, capital accumulation led to wealth on the one side and destitution on the other, giving rise to Malthus's famous theory. However, during the 19th century these social inequalities gradually evened out. After World War II, the question arose of whether the populations of other civilizations (Confucian, Japanese, Islamic, Hindu, Slavic-Orthodox, Latin American, and African) would also undergo a demographic transition and how soon. At any rate, developed country population size, as a percentage of global population, will drop from 22% to 13%, and that of Africa will increase from 12% to 26%, during the 21st century. PMID:12292830

  3. Population differentiation without speciation

    PubMed Central

    Magurran, A. E.

    1998-01-01

    Population differentiation is often viewed as an important step towards speciation, and part of the rationale for conserving variation at the intraspecific level is that the potential to generate more biological diversity should be retained. Yet, speciation is not an inevitable consequence of population divergence. This paper reviews recent work on the Trinidadian guppy, Poecilia reticulata, a species that is renowned for its capacity for population differentiation. Guppy populations evolve rapidly, within 101 to 102 generations, as a response to changes in selection exerted by predators. The rates of evolution involved can be up to seven orders of magnitude greater than those seen in the fossil record. Sexual selection, particuarly female choice, appears to reinforce the divergence that natural selection has generated. Perplexingly, however, there is no reproductive isolation (either prezygotic or postzygotic) between populations, even those that have been separated for at least 106 generations. Sexual conflict may be the key to explaining this absence of speciation. Male reproductive behaviour, particularly the high incidence of sneaky mating, may be instrumental in producing sufficient gene flow to prevent reproductive isolation. Sneaky mating has the potential to undermine female choice, and is known to be an important means of sperm transfer in wild populations. Sexual dimorphism, also a result of sexual conflict in guppies, may inhibit speciation in another way. Morphological differences between the sexes, that have arisen for reproductive reasons, mean that males and females are pre-adapted for different foraging niches. This, in turn, reduces the opportunity for the development of feeding polymorphisms, a mechanism that seems to have been important in the sympatric speciation of other fish species.

  4. Having quality population.

    PubMed

    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

  5. Highways and Population Change

    ERIC Educational Resources Information Center

    Voss, Paul R.; Chi, Guangqing

    2006-01-01

    In this paper we return to an issue often discussed in the literature regarding the relationship between highway expansion and population change. Typically it simply is assumed that this relationship is well established and understood. We argue, following a thorough review of the relevant literature, that the notion that highway expansion leads to…

  6. Fitness in Special Populations.

    ERIC Educational Resources Information Center

    Shephard, Roy J.

    This book examines fitness research among special populations, including research on fitness assessment, programming, and performance for persons with various forms of physical disabilities. The book covers such topics as diseases that complicate life in a wheelchair, disability classifications, physiological responses to training, positive…

  7. [Population and development].

    PubMed

    Trias, M

    1987-01-01

    Human reproduction and development are contrasted; they are intimately linked despite the fact that they may be considered antitheses of each other from many points of view. Presently technological development and the advance of humans into every available corner of living space threaten to place the whole world environment in danger. The Green revolution of the 1960s addressed problems of underproduction of food for the world's population, without providing for the effective distribution of the new surpluses, and without addressing the problem of the ecological impact. 2 trends which are regarded by some with alarm: the migration of populations to the cities and the aging of the population with the connected burden on health care systems, are inevitable, and it is not clear that they are completely negative trends. Addressing these issues will have positive effects in the long run: congestion in the cities, the result of mechanization of rural industry which also results in a greater abundance of agricultural products necessary to society, should force serious consideration of problems such as solid waste management. Coming to terms with the costs of intervention to save lives among the very frail elderly and the prematurely born will have the effect of bringing controversial topics such as euthenasia and eugenics to discussion. The important role played by economic development in the braking of population expansion is underlined. PMID:12315175

  8. [Population census, 1980].

    PubMed

    Suharto, S

    1980-12-01

    The author describes the types of data collected in the 1980 population census of Indonesia, considers the differences between the 1971 and 1980 censuses, and discusses which data and tables are scheduled to be published. A copy of the census questionnaire and an explanation of the concepts and definitions used are also included. PMID:12338729

  9. Mentoring Special Youth Populations

    ERIC Educational Resources Information Center

    Britner, Preston A.; Balcazar, Fabricio E.; Blechman, Elaine A.; Blinn-Pike, Lynn; Larose, Simon

    2006-01-01

    Whereas mentoring programs are well received as support services, very little empirical research has been conducted to assess the effectiveness of these programs to meet the diverse needs of different special populations of youth. Potentially useful theoretical orientations (attachment, parental acceptance-rejection, social support, adult…

  10. Working with Specific Populations.

    ERIC Educational Resources Information Center

    Cramer, David; And Others

    This document consists of the second section of a book written to educate and inform those in the helping professions on how to deal with Acquired Immune Deficiency Syndrome (AIDS). The five chapters in section 2 focus on diversity, each dealing with a special population with its own needs and a unique way of handling issues associated with AIDS.…

  11. Puppets and Population.

    ERIC Educational Resources Information Center

    Baird, Bil

    This document focuses on the use of puppets for educating the illiterate populations of the world in food production and family planning. It is presented as one practical and effective tool for the adult educator and literacy worker. When used as part of a total program of functional literacy for family life planning, it can help young adults gain…

  12. Population and Development Issues.

    ERIC Educational Resources Information Center

    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)

  13. Stellar population in LLAGN

    NASA Astrophysics Data System (ADS)

    González Delgado, Rosa M.

    2004-11-01

    LLAGN that include low-ionization nuclear emission-line regions (LINERs), and transition-type objects (TOs) represent the most common type of nuclear activity. Here, a study of the central stellar population of LLAGN is presented. Our goal is to search for spectroscopic signatures of young and intermediate age stars, and to investigate their relationship with the ionization mechanism in LLAGN. The method used is based on the stellar population synthesis of the UV-optical continuum of the innermost (20-100 pc) regions in these galaxies. Half of the LINERs and TOs of the Palomar catalogue are analysed. It is found that weak-[OI] ([OI]/Hα≤0.25) LLAGN have an intermediate age stellar population that dominates the optical light. But young stellar clusters dominate the UV continuum in these objects. These clusters can co-exist with a black-hole in spatial scales of a few pc. Most of the strong-[OI] LLAGN have a predominantly old stellar population. These results suggest that young and intermediate age stars do not play a significant role in the ionization of LLAGN with strong [OI].

  14. [Population trends and poverty].

    PubMed

    Olmedo, C

    1998-04-01

    Implications of population growth in Ecuador for the quality of life of the poor population are analyzed. It is argued that if the gross national product (GNP) were to grow at a sustained annual rate of 5% or more, demographic trends would not present a significant obstacle to reducing poverty. National economic projections are for growth of only 2.5-3.5% annually. The continuing rapid growth of the poor population despite general slowing of demographic growth, the young age structure, the need for increased formal education to enable the poor to overcome their poverty, and the effect of unemployment on the dependency ratio will tend to hamper improvements in average productivity and per capita GNP. The need for spending on education, health, basic services, and housing will divert funds away from productive investment, generating a direct negative impact on economic growth. Over half of Ecuadorian children suffer from some degree of malnutrition, indicating that food production is inadequate to meet demand. The export-oriented agricultural policy and poor weather have led to a chronic shortage of basic foods. Progressive increase and diversification of agricultural production, along with maintenance of low prices and substantial increases in income levels and agricultural productivity, will be required if the entire population is to be fed adequately. Intense efforts will be needed from all sectors to bring demographic growth into balance with economic and development needs. PMID:12178231

  15. [The Marxist outlook on population].

    PubMed

    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

  16. Absorption and translocation of 4-(trifluoromethyl)chlorobenzene in soil and crops

    SciTech Connect

    Cacco, G.; Ferrari, G.

    1982-01-01

    Water containing 1 mg/L 4-(trifluoro(/sup 14/C)methyl)chlorobenzene (TFCB) was supplied to pot cultures of three grass (Zea mays L.; Festuca rubra L.; Lolium multiflorum L.) and three legume (Vicia sativa L.; Trifolium perenne L.; Medicago sativa L.) species. The chemical was absorbed by soil and subsequently translocated to plant leaves at increasing amounts for maize to ryegrass, clover, alfalfa, red fescue, and vetch. Legumes showed a high capacity of degradation of the contaminant, suggesting their utilization to reclaim soil and water contaminated by TFCB.

  17. Herbicidal, plant growth inhibitory, and cytotoxic activities of bismuthines containing aromatic heterocycles.

    PubMed

    Céspedes, Carlos L; Lemus, Adela; Salazar, Juan R; Cabrera, Armando; Sharma, Pankaj

    2003-05-01

    This work presents the herbicidal and plant growth regulatory activities of tertiary bismuthines containing heterocyclic aromatic rings of the general formula (2-C(4)H(3)X)(3)Bi, where X = S (3), O (1), or NMe (2). Toxicity against Artemia salina and herbicidal activity on Lactuca sativa, Trifolium pratense, and Lolium multiflorum were tested. In addition to the effects on mitochondrial respiration obtained from roots of Phaseolus vulgaris, these compounds also demonstrated partial radical scavenging properties against 2,2-diphenyl-1-picrylhydrazyl (DPPH). The furyl substituent is the most important structural requirement for the activity measurements observed in this study. PMID:12720372

  18. Human Population Admixture in Asia

    PubMed Central

    2012-01-01

    Genetic admixture in human, the result of inter-marriage among people from different well-differentiated populations, has been extensively studied in the New World, where European colonization brought contact between peoples of Europe, Africa, and Asia and the Amerindian populations. In Asia, genetic admixing has been also prevalent among previously separated human populations. However, studies on admixed populations in Asia have been largely underrepresented in similar efforts in the New World. Here, I will provide an overview of population genomic studies that have been published to date on human admixture in Asia, focusing on population structure and population history. PMID:23166524

  19. Population attribute compression

    DOEpatents

    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.

  20. Equatorially trapped plasma populations

    NASA Technical Reports Server (NTRS)

    Olsen, R. C.

    1981-01-01

    The SCATHA observations of the equatorially trapped plasmas are presented in order to emphasize the importance of making measurements at the equator. The UCSD plasma detector and the GSFC electric field experiment are described, as are the pertinent characteristics of the magnetometer and mass spectrometers. The electron distribution reveals a width of 20 deg to 60 deg, narrowing with increasing energy. The 20- to 100-eV ion fluxes typically exhibit temperatures in the 20to 50-eV range and densities of 1-10 per cu cm. The electron population typically ranges from 50 to 500 eV, with temperatures of 100-200 eV and densities also in the 1-10 per cu cm range. Field-aligned populations of lower energy are occasionally found in both ions and electrons at the same location.

  1. Population, environment and development.

    PubMed

    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

  2. Magnetospheric particle populations.

    NASA Technical Reports Server (NTRS)

    Vette, J. I.

    1972-01-01

    Significant results of magnetospheric charged particle measurements conducted within the past two years are reviewed in an attempt to provide a general description of relationships among particle populations in the magnetosheath, plasma sheet, extraterrestrial ring current region, electron trough, pseudotrapping region, and stable-trapping region. Special attention is given to the characteristics of protons, electrons, alpha particles, and particles with charge greater than three in the stable trapping region.

  3. [Poverty and population growth].

    PubMed

    1983-07-01

    In the mid-1970s, some 120 million Latin Americans were unable to satisfy their most basic material needs. 55 million of them were in extreme indigency, unable to satisfy their minimal food needs even by using their entire incomes for that purpose. The rapid rate of demographic growth in Latin America influences the growth of the poor strata, who in absolute and relative terms show the highest rates of population growth. Despite heterogeneity in the manifestations of poverty, the poor have certain traits in common: employment outside the modern sector, with low productivity and little hope of generating stable incomes, low consumption capability, and lack of political power. 1 of the great problems of economic development in Latin America is the exclusion of the poorest strata from employment in better paid jobs. The high rate of fertility and rapid population growth provoke a negative interaction between population and development, in which the poorest strata reproduce most rapidly, becoming even poorer. A program of family planning within a development effort providing employment and income is needed to mitigate the problem, and no avenue or effort of implementation should be neglected on ideological grounds. Between 1960-70, the share of the poorest 20% of the population declined from 3.1% to 2.5% of the toal income of the region, while that of the poorest 1/2 increased slightly from 13.4% to 13.9%. In 1970 the poorest 20% had a per capita income of about US $70/year. It has been estimated that the proportion of the poor in Latin America declined from 51% in 1960 to 40% in 1970 and 33% at present, but the absolute number of persons affected continues to increase. PMID:12339314

  4. [Population, ethics and equity].

    PubMed

    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

  5. Food and population.

    PubMed

    1985-04-01

    Agricultural producttivity is currently characterized by the paradox of an abundace of food in the developed world and hunger in much of the developing world. In China, India, and many other countries of Asia, the general food supply has kept pace with population growth and should continue to if family planning programs gain momentum. In Africa, on the other hand, the food supply has been falling behind the growth of the population in the majority of countries for the past decade. The situation is especially serious in the Sahel, where the production wf crops for export has been prioritized over local needs. The Food and Agriculture Organization's global information and early warning system is a promising development and can provide alerts when weather or other conditions threaten a harvest. Donor countries can then send in cereals and other foods before there is an actual famine. About 20 disasters in the Sahel are etimated to have been averted by this system, in operation since 1975. In developed countries, the farming industry needs to be restructured in relation to changes in markets and technologies. Solution of the food-population problem depends upon agricultural policies that balance the economic interests of farmers and consumers and also takes into account the need to preserve the countryside. PMID:2858671

  6. Stellar population synthesis

    NASA Astrophysics Data System (ADS)

    Zhang, Feng-Hui; Li, Li-Fang; Han, Zhan-Wen

    In this paper we review the study of stellar population synthesis. So far there exist three methods in the study of the integrated light of stellar population-trail-and error, automated, and evolutionary population synthesis (EPS). We have discussed advantages and disadvantages for these methods. Among the three methods the EPS is the most direct approach to model galaxies. In this scheme, the model builder starts with knowledge of stellar evolution and attempts to build a model galaxy with physical input parameters such as star formation rate (SFR) and the initial mass function (IMF) slope. Therefore we have discussed emphatically the EPS method. First we have described and given the often used grids of several key ingredients in the EPS studies: (1) the library of evolutionary tracks used to calculate isochrones in the color-magnitude diagram (CMD), (2) the libraries of spectra adopted, which include empirical and theoretical stellar spectral libraries, star cluster library, active galactic nuclear (AGN) library and galaxy library, to derive the integrated spectral energy distributions (ISED) or magnitudes and colors in the suitable passbands, (3) the IMF used to evaluate the relative proportions of stars in the various evolutionary phases, and (4) the assumption for the underlying star formation rate (SFR) and chemical enrichment. Then we have listed several population synthesis criterions, i.e. broadband color indices, the integrated spectral energy distribution (ISED) and narrow band color indices, given the basic method of calculating broadband colors and flux-distribution for a simple stellar population (SSP). At last we have discussed simply the existed limitations, which are caused by some uncertainties in its two principal building blocks: stellar evolution models and spectral libraries in the studies of the EPS. Stellar evolution models are often subject to limitations in the following areas: the atomic data (radiative opacities, heavy element mixture

  7. Population synthesis of massive stars

    NASA Astrophysics Data System (ADS)

    Vanbeveren, Dany

    2014-09-01

    This review deals with massive star population synthesis with a realistic population of binaries. We focus on the comparison between observed star numbers (as a function of metallicity) and theoretically predicted numbers of stellar populations in regions of continuous star formation and in starburst regions. Special attention is given to the O-type/WR/red supergiant stellar population, the population of blue supergiants, the pulsar and binary pulsar population, and the supernova rates. Finally, we consider massive double compact star mergers and the link with gravitational wave sources (the advanced LIGO II) and r-process element production sites.

  8. An optimum world population.

    PubMed

    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

  9. Canada's population is aging.

    PubMed

    Verma, Jennifer; Samis, Stephen

    2011-01-01

    Canada's population is aging, and the authors of this issue's lead article, Neena Chappell and Marcus Hollander, present a policy prescription for how to design a healthcare system that better responds to needs of older Canadians. The timing of this issue of Healthcare Papers is important: the first of the baby boomers turned 65 in January 2011. There is a pressing need to develop policies and implement sustainable reforms that will allow older adults to stay healthier and maintain their independence longer in their place of choice, while also creating efficiencies and quality improvements in our overall healthcare system that will benefit Canadians of all ages. PMID:21464621

  10. [Roma populations and health].

    PubMed

    Jackson, Y; Tabin, J P; Hourton, G; Bodenmann, P

    2015-03-25

    The health status of the so-called "Roma" is usually much poorer than that of neighbouring non-Roma populations with a life expectancy gap of 5-15 years. This results from prolonged exposure to adverse determinants of health and to persistent exclusion from social and political arenas. Scientific and social research has only poorly addressed the health issues of Roma and evidences are scarce. Insufficient access to public services, including to health care and non optimal clinical practices are modifiable factors. If correctly addressed, this could contribute to reduce health disparities, including in Switzerland. PMID:26027205

  11. Population in Perspective: Regional Views. A Population Learning Series.

    ERIC Educational Resources Information Center

    Population Reference Bureau, Inc., Washington, DC.

    The world's population faces a series of problems that are similar in all countries, although more exacerbated in developing nations. This population study presents statistical facts and information concerning developed and developing nations and their populations, growth, the status of women, migration, the labor force, changing age structures,…

  12. Population Trends and the Status of Population Policy in Africa.

    ERIC Educational Resources Information Center

    Rogge, John R.

    1982-01-01

    The major trend towards worldwide easing of the birthrate does not include the current population patterns in Africa. The population policies of African nations range along a continuum from totally pronatal to strongly antinatal. However, even antinatal policies have had little effect on the overall spiralling upward population trend. (JA)

  13. Population and sustainable development.

    PubMed

    Visaria, P

    1989-01-01

    This paper assesses the feasibility of sustainable development for various low-income countries in the context of prospective population growth. In that context, development that is sustainable is development that does not endanger the natural systems that support life on earth. Since a short time has elapsed since the Mexico City Conference, not all the developmental goals highlighted at that meeting could be reviewed. Emphasis in this paper is placed on an assessment of recent trends in food production and availability, employment and poverty issues, with an emphasis on India, China, and a few other Asian countries on which the author has had access to information. In the view of the author, the key to sustained development in the face of likely continued population growth up to the end of the 21st century lies in technological change and effective use of the human and physical resources in developing countries. Adequate planning and judicious adaptation of the institutional framework can help to avoid the suffering and misery of millions of people currently alive and also those who will be born during further decades. PMID:12282630

  14. Genetics of population isolates.

    PubMed

    Arcos-Burgos, M; Muenke, M

    2002-04-01

    Genetic isolates, as shown empirically by the Finnish, Old Order Amish, Hutterites, Sardinian and Jewish communities among others, represent a most important and powerful tool in genetically mapping inherited disorders. The main features associated with that genetic power are the existence of multigenerational pedigrees which are mostly descended from a small number of founders a short number of generations ago, environmental and phenotypic homogeneity, restricted geographical distribution, the presence of exhaustive and detailed records correlating individuals in very well ascertained pedigrees, and inbreeding as a norm. On the other hand, the presence of a multifounder effect or admixture among divergent populations in the founder time (e.g. the Finnish and the Paisa community from Colombia) will theoretically result in increased linkage disequilibrium among adjacent loci. The present review evaluates the historical context and features of some genetic isolates with emphasis on the basic population genetic concepts of inbreeding and genetic drift, and also the state-of-the-art in mapping traits, both Mendelian and complex, on genetic isolates. PMID:12030885

  15. Migration of the population.

    PubMed

    Krasinets, E

    1998-03-01

    Two factors influence foreign migration balance of the Russian Federation. The first factor involves the migration process between Russia and former union republics. The influx of population to the Russian Federation from other republics of the former Soviet Union is considered as one of the largest in the world. The average annual migratory growth of Russia during the years 1991-94 as a result of this migration exchange has tripled as compared with 1986-90, with a total of 2.7 million Russians who migrated into Russia. However, from 1996 up to the present time, the number of persons arriving in Russia declined dramatically. Meanwhile, the second factor that determines the country's migration balance is emigration to the far abroad. The most significant trend in determining the development of internal migration in Russia is the outflow of population from northern and eastern regions. The directions of internal and external migratory flows have a large influence on the migration balance in Russia's rural areas. The reduction of migratory flows in rural areas is the direct result of processes in the economic sphere. It confirms the reconstruction of rural-urban migratory exchange. PMID:12294009

  16. POPULATION III HYPERNOVAE

    SciTech Connect

    Smidt, Joseph; Whalen, Daniel J.; Wiggins, Brandon K.; Even, Wesley; Fryer, Chris L.; Johnson, Jarrett L.

    2014-12-20

    Population III supernovae have been of growing interest of late for their potential to directly probe the properties of the first stars, particularly the most energetic events that are visible near the edge of the observable universe. Until now, hypernovae, the unusually energetic Type Ib/c supernovae that are sometimes associated with gamma-ray bursts, have been overlooked as cosmic beacons at the highest redshifts. In this, the latest of a series of studies on Population III supernovae, we present numerical simulations of 25-50 M {sub ☉} hypernovae and their light curves done with the Los Alamos RAGE and SPECTRUM codes. We find that they will be visible at z = 10-15 to the James Webb Space Telescope and z = 4-5 to the Wide-Field Infrared Survey Telescope, tracing star formation rates in the first galaxies and at the end of cosmological reionization. If, however, the hypernova crashes into a dense shell ejected by its progenitor, it is expected that a superluminous event will occur that may be seen at z ∼ 20 in the first generation of stars.

  17. Massive Stars: Stellar Populations

    NASA Astrophysics Data System (ADS)

    Bianchi, Luciana

    2007-07-01

    Massive stars dominate the chemical and dynamical evolution of the ISM, and ultimately of their parent galaxy and the universe, because of their fast evolution and intense supersonic winds. Four decades ago, the first rocket UV spectra of massive stars revealed the importance of mass loss and began to change our understanding of their evolution. Recently, advances in stellar modeling, and the observation of crucial ions in the far-UV spectral range, led to the resolution of long-standing issues in our understanding of massive star atmospheres. A revised (downwards) calibration of Teff for early spectral types is emerging as a result. Meanwhile, HST imaging, and large ground-based telescopes with multislit spectroscopic capabilities, had opened the possibility of resolved studies of stellar populations in Local Group galaxies, which sample a variety of metallicity and environment conditions. More recently, GALEX is providing a global, deep view of the young stellar populations for hundreds of nearby galaxies, revealing their recent star-formation history and modalities. The wide-field coverage and sensitivity of the GALEX UV imaging, easily detecting extremely low levels of star formation, is again changing some of our views on massive star formation in galaxies.

  18. Population's political clout.

    PubMed

    Schima, M E; Viel, B; Chen, P C; Gille, H; Epstein, S G

    1980-03-01

    China's birth planning program has its own separate administrative hierarchy. The political commitment to population planning which originates with the top leadership extends to peer pressure exerted on couples at the brigade and neighborhood level. While family planning services are primarily delivered in health structures, responsibility for the population program falls to the Leading Group on Birth Planning. Not only health officials but also officials responsible for economic planning, political propaganda, scientific research, trade unions, women's affairs, and all those whose participation is considered necessary to the program's success attend meeting. The Leading Group on Birth Planning is chaired by a Vice-Premier. At each administrative level, provincial to work brigade, the same pattern is repeated: centralized responsibility combined with broad representation and high-level potitical leadership. With a tight, working structure, China has been able to enact its birth control program with remarkable speed and effectiveness. Each production brigade has its own planned birth leading group headed by the captain of the brigade or the captain of the women's team. The leading group supervises the barefoot doctors, midwives, and team level health aides who deliver contraceptives to households or accompany people to the community health center to obtain surgical services. PMID:12261795

  19. NASA Orbital Debris Baseline Populations

    NASA Technical Reports Server (NTRS)

    Krisko, Paula H.; Vavrin, A. B.

    2013-01-01

    The NASA Orbital Debris Program Office has created high fidelity populations of the debris environment. The populations include objects of 1 cm and larger in Low Earth Orbit through Geosynchronous Transfer Orbit. They were designed for the purpose of assisting debris researchers and sensor developers in planning and testing. This environment is derived directly from the newest ORDEM model populations which include a background derived from LEGEND, as well as specific events such as the Chinese ASAT test, the Iridium 33/Cosmos 2251 accidental collision, the RORSAT sodium-potassium droplet releases, and other miscellaneous events. It is the most realistic ODPO debris population to date. In this paper we present the populations in chart form. We describe derivations of the background population and the specific populations added on. We validate our 1 cm and larger Low Earth Orbit population against SSN, Haystack, and HAX radar measurements.

  20. False precision and population science.

    PubMed

    Weigel, G

    1994-09-01

    The author compares proponents of reducing population growth to alchemists and astrologers, thereby whole-heartedly dismissing the validity of the field of population science. His vitriolic essay argues thus: population science cannot predict the growth rate of human populations over long periods of time, population science can determine neither when nor how fertility rates will decline, only 10% of developing country populations are covered by reliable vital statistic registration systems, and population science has no scientifically precise definition of overpopulation. The images of disease, hunger, and overcrowding evoked by the notion overpopulation are instead due to poverty and material deprivation. Were delegates to the 1994 UN International Conference on Population and Development to address these real, latter issues, positive social change may result. Since conference attendees are, however, committed to a narrowly focused and flawed agenda, the world should dismiss conference policies as the nonsense that they are. PMID:12345660

  1. Frequently Asked Questions about Population.

    ERIC Educational Resources Information Center

    California Journal of Science Education, 2000

    2000-01-01

    Emphasizes the issue of human population growth. Provides information on current demographic trends; their social, economic, and environmental impacts; and Zero Population Growth's (ZPG) position on several controversial topics. (ASK)

  2. Correlations and Neuronal Population Information.

    PubMed

    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. PMID:27145916

  3. Autecology in Rhizospheres and Nodulating Behavior of Indigenous Rhizobium trifolii†

    PubMed Central

    Demezas, David H.; Bottomley, Peter J.

    1986-01-01

    Indigenous serotype 1-01 of Rhizobium trifolii occupied significantly fewer nodules (6%) on plants of soil-grown noninoculated subterranean clover (Trifolium subterraneum L.) cv. Woogenellup than on cv. Mt. Barker (36%) sampled at the flowering stage of growth. Occupancy by indigenous serotype 2-01, was not significantly different on the two cultivars (16 and 26%). Serotype-specific, fluorescent-antibody conjugates were synthesized and used to enumerate the indigenous serotypes in host (clovers) and nonhost (annual rye-grass, Lolium multiflorum L.) rhizospheres and in nonplanted soil. The form and concentration of Ca2+ in the flocculating mixture and the presence of phosphate anions in the extracting solution were both critical for enumerating R. trifolii in Whobrey soil. The two serotypes were present in similar numbers in nonplanted soil (ca. 106 per g of soil) and each represented ca. 10% of the total R. trifolii population. Although host rhizospheres did not preferentially stimulate either serotype, the mean population densities of serotype 2-01 were significantly greater (P = 0.05) than those of serotype 1-01 in clover rhizospheres on 8 of 14 samplings made between the time of seeding and the appearance of nodules (day 12). In this experiment, and in contrast to our earlier findings, serotype 1-01 occupied significantly fewer (P ≤ 0.05) of the nodules (7 to 16%) on both cultivars than serotype 2-01 (51%) when sampled at 4 weeks. Differences between cultivars became apparent as the plants matured. There was a threefold increase (7 to 21%) in nodules occupied by serotype 1-01 on cv. Mt. Barker between 4 and 16 weeks. This was accompanied by increases in nodules coinhabited by both nonidentifiable occupants and either serotype 1-01 (0 to 20%) or 2-01 (11 to 51%). No increases in either of these parameters were observed on cv. Woogenellup. PMID:16347198

  4. Teaching Population Concepts. Revised Edition.

    ERIC Educational Resources Information Center

    King, Pat; Landahl, John

    This edition is designed to help teachers provide their students with some basic population concepts with stress placed on the elements of decision making. In the first section of the pamphlet, some of the basic concepts of population study are presented. These include populations, growth rates, birth and death rates, doubling time, migration, age…

  5. A Population of Assessment Tasks

    ERIC Educational Resources Information Center

    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."

  6. Psychology and Population: An Overview.

    ERIC Educational Resources Information Center

    Fawcett, James T.

    Psychology and Population is defined as the study of individual dispositions and behavior that affect the size, structure and dispersion of the population, and the way in which acts of individuals enter into the dynamics of population change. Even this definition was viewed as inadequate, ignoring, as it does, the reciprocal effect of population…

  7. Population and Development [Issue Packet].

    ERIC Educational Resources Information Center

    American Freedom from Hunger Foundation, Washington, DC.

    A variety of informational materials is compiled in this issue packet concentrating on population and development. The materials have been assembled to understand the issues associated with the facts of the world's population and to try to invent new forms of action and thought necessary to find the possibilities hidden in the population issue.…

  8. [Changes in the Gypsy population].

    PubMed

    Hooz, I

    1987-01-01

    The problems involved in estimating the numbers of the Gypsy population in Hungary are described. The author describes the first census of Gypsies carried out in 1983 and other attempts to survey this population. A comparative analysis of changes in the age distribution of the Gypsy and general population over the past 100 years is included. (SUMMARY IN ENG AND RUS) PMID:12341019

  9. Population Education: A Knowledge Base.

    ERIC Educational Resources Information Center

    Jacobson, Willard J.

    To aid junior high and high school educators and curriculum planners as they develop population education programs, the book provides an overview of the population education knowledge base. In addition, it suggests learning activities, discussion questions, and background information which can be integrated into courses dealing with population,…

  10. The politics of population.

    PubMed

    1994-09-01

    Whatever succeeds or fails to materialize at the UN Conference on Population and Development in Cairo, most of the peoples of the Earth are represented in one room where their common future is being charted. That is a staggering achievement after the chaotic and fragmented history of the human race up to this point. It is less a development willed by foresighted leaders than an inevitable response to the shrinkage of the planet due to population growth and resource depletion--plus the advent of instantaneous worldwide communication. Some of the alliances, disputes and side issues are momentous. There are governments dedicated to policies of controlling population, such as Egypt and the Philippines, in conflict with their own religious authorities. The Catholic Church finds itself in lock-step with the Islamic theologians opposing birth control and condemning abortion, raising the possibility of a previously unthinkable ecumenical breakthrough to add to the Vatican's dialogues with Protestant Christians and with Jews. There is President Hosni Mubarak of Egypt who wanted to host the conference to show off the stability of his country and regime, only to demonstrate the opposite as extremists threatened the same terror against delegates they have inflicted on tourists. Some Islamic regimes stayed away. There is the ultimate Western feminism and environmentalism expressed by Prime Minister Gro Harlem Brundtland of Norway. And an astounding expression of women's rights to control such matters as childbearing, expressed by Prime Minister Benazir Bhutto of Pakistan, braving the wrath of clerics in her own country to attend, combined with a forceful denunciation of abortion startling to many of her Western admirers. The seriousness of the US effort, led by Vice President Al Gore, to pass a meaningful document that will frame policy for world organizations, contrasts with the previous indifference of the predecessor Reagan and Bush administrations to the issue. The effort

  11. The population slide.

    PubMed

    Mukerjee, M

    1998-12-01

    The level of total fertility in Bangladesh has fallen from 7 in 1975 to 3 today, the sharpest fertility transition in South Asia. Fertility decline in Bangladesh and Nepal follows such transition occurring first in Sri Lanka, then in India. While in Western countries, levels of fertility began to fall once an advanced stage of development had been reached, these new declines in South Asia are not directly correlated with indicators of development such as increased literacy or the alleviation of poverty. Bangladesh has experienced major fertility decline despite being one of the world's 20 poorest countries. Fertility decline in Bangladesh may be attributed to a combination of an effective government family planning program, a general desire among Bangladesh's population to bear fewer children, reductions in mortality, the availability of microcredit, changes in women's status, and the provision of health and family planning information over the radio 6 hours per day. PMID:9867622

  12. Population and the World Bank.

    PubMed

    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

  13. Discreteness effects in population dynamics

    NASA Astrophysics Data System (ADS)

    Guevara Hidalgo, Esteban; Lecomte, Vivien

    2016-05-01

    We analyse numerically the effects of small population size in the initial transient regime of a simple example population dynamics. These effects play an important role for the numerical determination of large deviation functions of additive observables for stochastic processes. A method commonly used in order to determine such functions is the so-called cloning algorithm which in its non-constant population version essentially reduces to the determination of the growth rate of a population, averaged over many realizations of the dynamics. However, the averaging of populations is highly dependent not only on the number of realizations of the population dynamics, and on the initial population size but also on the cut-off time (or population) considered to stop their numerical evolution. This may result in an over-influence of discreteness effects at initial times, caused by small population size. We overcome these effects by introducing a (realization-dependent) time delay in the evolution of populations, additional to the discarding of the initial transient regime of the population growth where these discreteness effects are strong. We show that the improvement in the estimation of the large deviation function comes precisely from these two main contributions.

  14. Population subdivision and adaptation in asexual populations of Saccharomyces cerevisiae.

    PubMed

    Kryazhimskiy, Sergey; Rice, Daniel P; Desai, Michael M

    2012-06-01

    Population subdivision limits competition between individuals, which can have a profound effect on adaptation. Subdivided populations maintain more genetic diversity at any given time compared to well-mixed populations, and thus "explore" larger parts of the genotype space. At the same time, beneficial mutations take longer to spread in such populations, and thus subdivided populations do not "exploit" discovered mutations as efficiently as well-mixed populations. Whether subdivision inhibits or promotes adaptation in a given environment depends on the relative importance of exploration versus exploitation, which in turn depends on the structure of epistasis among beneficial mutations. Here we investigate the relative importance of exploration versus exploitation for adaptation by evolving 976 independent asexual populations of budding yeast with several degrees of geographic subdivision. We find that subdivision systematically inhibits adaptation: even the luckiest demes in subdivided populations on average fail to discover genotypes that are fitter than those discovered by well-mixed populations. Thus, exploitation of discovered mutations is more important for adaptation in our system than a thorough exploration of the mutational neighborhood, and increasing subdivision slows adaptation. PMID:22671557

  15. Population Analysis: Communicating in Context

    NASA Technical Reports Server (NTRS)

    Rajulu, Sudhakar; Thaxton, Sherry

    2008-01-01

    Providing accommodation to a widely varying user population presents a challenge to engineers and designers. It is often even difficult to quantify who is accommodated and who is not accommodated by designs, especially for equipment with multiple critical anthropometric dimensions. An approach to communicating levels of accommodation referred to as population analysis applies existing human factors techniques in novel ways. This paper discusses the definition of population analysis as well as major applications and case studies. The major applications of population analysis consist of providing accommodation information for multivariate problems and enhancing the value of feedback from human-in-the-loop testing. The results of these analyses range from the provision of specific accommodation percentages of the user population to recommendations of design specifications based on quantitative data. Such feedback is invaluable to designers and results in the design of products that accommodate the intended user population.

  16. Pharmacogenetics: detecting sensitive populations.

    PubMed Central

    Shields, P G

    1994-01-01

    Risk assessment models strive to predict risks to humans from toxic agents. Safety factors and assumptions are incorporated into these models to allow a margin of error. In the case of cancer, substantial evidence shows that the carcinogenic process is a multistage process driven by the interaction of exogenous carcinogenic exposures, genetic traits, and other endogenous factors. Current risk assessment models fail to consider genetic predispositions that make people more sensitive or resistant to exogenous exposures and endogenous processes. Several cytochrome P450 enzymes, responsible for metabolically activating carcinogens and medications, express wide interindividual variation whose genetic coding has now been identified as polymorphic and linked to cancer risk. For example, a restriction fragment-length polymorphism for cytochrome P4501A1, which metabolizes polycyclic aromatic hydrocarbons, and cytochrome P4502E1, which metabolizes N-nitrosamines and benzene, is linked to lung cancer risk. Cytochrome P4502D6, responsible for metabolizing many clinically important medications, also is linked to lung cancer risk. The frequency for each of these genetic polymorphisms vary among different ethnic and racial groups. In addition to inherited factors for the detection of sensitive populations, determining the biologically effective doses for carcinogenic exposures also should quantitatively and qualitatively enhance the risk assessment process. Levels of carcinogen-DNA adducts reflect the net effect of exposure, absorption, metabolic activation, detoxification, and DNA repair. These effects are genetically predetermined, inducibility notwithstanding. The combination of adduct and genotyping assays provide an assessment of risk that reflects recent exogenous exposure as well as one's lifetime ability to activate and detoxify carcinogens. PMID:7737047

  17. Modeling sandhill crane population dynamics

    USGS Publications Warehouse

    Johnson, D.H.

    1979-01-01

    The impact of sport hunting on the Central Flyway population of sandhill cranes (Grus canadensis) has been a subject of controversy for several years. A recent study (Buller 1979) presented new and important information on sandhill crane population dynamics. The present report is intended to incorporate that and other information into a mathematical model for the purpose of assessing the long-range impact of hunting on the population of sandhill cranes.The model is a simple deterministic system that embodies density-dependent rates of survival and recruitment. The model employs four kinds of data: (1) spring population size of sandhill cranes, estimated from aerial surveys to be between 250,000 and 400,000 birds; (2) age composition in fall, estimated for 1974-76 to be 11.3% young; (3) annual harvest of cranes, estimated from a variety of sources to be about 5 to 7% of the spring population; and (4) age composition of harvested cranes, which was difficult to estimate but suggests that immatures were 2 to 4 times as vulnerable to hunting as adults.Because the true nature of sandhill crane population dynamics remains so poorly understood, it was necessary to try numerous (768 in all) combinations of survival and recruitment functions, and focus on the relatively few (37) that yielded population sizes and age structures comparable to those extant in the real population. Hunting was then applied to those simulated populations. In all combinations, hunting resulted in a lower asymptotic crane population, the decline ranging from 5 to 54%. The median decline was 22%, which suggests that a hunted sandhill crane population might be about three-fourths as large as it would be if left unhunted. Results apply to the aggregate of the three subspecies in the Central Flyway; individual subspecies or populations could be affected to a greater or lesser degree.

  18. Genetic differentiation of Jewish populations.

    PubMed

    Klitz, W; Gragert, L; Maiers, M; Fernandez-Viña, M; Ben-Naeh, Y; Benedek, G; Brautbar, C; Israel, S

    2010-12-01

    The Jewish diaspora can be viewed as a natural process in population dispersion and differentiation. We extend genetic studies on the Jewish diaspora to an analysis of human leukocyte antigen (HLA) haplotype distributions in the Jewish peoples, and show the value of this information for the design of Jewish marrow donor registries. HLA data from the Hadassah Bone Marrow Registry having parental country-of-origin information comprise samples of geographically discrete regions. We analyzed the HLA allele and haplotype frequencies for each national sample using population genetic and clustering methods. Population differentiation among diaspora populations was shown on the basis of HLA haplotype frequencies, including differences within the more recently diverged European groups. A method of haplotype and population clustering showed patterns of unique haplotype affinities associated with specific Jewish populations. The evidence showed that diaspora Jewish populations can be sorted into distinct clades of which the Ashkenazi are but one. Relationships among Jewish populations are interpretable in light of the historical record. We suggest that a major contributing factor to the genetic divergence between Jewish groups may have been admixture with local host populations, while, at the same time, threads of Eastern Mediterranean ancestry remain evident. PMID:20860586

  19. [Population control and environment protection].

    PubMed

    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

  20. Population-Sample Regression in the Estimation of Population Proportions

    ERIC Educational Resources Information Center

    Weitzman, R. A.

    2006-01-01

    Focusing on a single sample obtained randomly with replacement from a single population, this article examines the regression of population on sample proportions and develops an unbiased estimator of the square of the correlation between them. This estimator turns out to be the regression coefficient. Use of the squared-correlation estimator as a…

  1. USING POPULATION MODELS TO EVALUATE RISK IN POPULATION OF BIRDS

    EPA Science Inventory

    Wildlife populations are exposed to varying habitat structure and quality, as well as an array of human-induced environmental stressors. Predicting the consequences to a real population of one perturbation (e.g. a pesticide application) without considering other human activities ...

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

    USGS Publications Warehouse

    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.

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

    USGS Publications Warehouse

    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.

  4. The influence of plant species on the plant/air partitioning coefficients of PCBs and chlorinated benzenes

    SciTech Connect

    Koemp, P.; McLachlan, M.S.

    1995-12-31

    The plant/air partitioning coefficients (K{sub PA}) of pentachlorobenzene, hexachlorobenzene and 16 PCB congeners were determined in five different grass and herb species common to Central Europe (Lolium multiflorum, Trifolium repens, Plantago lanceolata, Crepis biennis, Achillea millefolium). The measurements were conducted between 5 C and 35 C using a solid phase fugacity meter. Octanol/air partition coefficients (K{sub OA}) were also measured over a similar temperature range. In all cases an excellent linear relationship between log K{sub PA} and log K{sub OA} was observed (r{sup 2} between 0.80 and 0.99). However, while the slope of this relationship was 1 for Lolium multiflorum (ryegrass), in agreement with previous work, the slopes of the log K{sub PA} vs. log K{sub OA} plot were less than 1 for the other 4 species, lying as low as 0.49 for Achillea millefolium (yarrow). Large differences in the enthalpy of phase change (plant/air) were also observed between the different species, but these differences were not related to the differences in the partition coefficients. These observations demonstrate that the contaminant storage properties of plants are variable, and that the lipophilic compartment in some plants is considerably more polar than octanol. This places constraints on the applicability of current models of plant uptake, almost all of which assume that the lipophilic compartment behaves like octanol, and reinforces the need for more research into the contaminant storage properties of plants.

  5. [Population policy: speeches and actions].

    PubMed

    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

  6. Interactions between populations and resources

    SciTech Connect

    Daily, G.C.

    1992-01-01

    Several unrelated projects, each dealing with the interactions between animal populations and their resources in evolutionary and community level contexts are presented. Three focus on the behavior of natural populations and communities of non-human species, while the other two explore several dimensions of human populations and resources. The first chapter investigates the factors that determine the spatial distribution of adults in an insect population and relates these to the evolution of insect mating systems. The second chapter describes subtle, indirect interactions in a keystone species complex comprised of a woodpecker, certain willow species, aspen trees, and a heartwood fungus. The third chapter examines the influence of social dominance status upon foraging behavior in large, heterospecific assemblages of birds at fruiting trees in Costa Rica. Several possible ramifications of social dominance hierarchies at the population and community levels are discussed. Chapter four describes the results of a stochastic simulation model of the effects of rapid climatic change on agriculture and the global human population. The model suggests that even favorable climatic changes may not prevent a several-fold increase in deaths (over past levels) if population growth outpaces food production by about 0.8 percent per annum or more. Finally, the fifth chapter outlines the current human population-environment situation and develops a framework for analyzing the carrying capacity of the planet for Homo sapiens. Biophysical and social dimensions of sustainability and carrying capacity are discussed.

  7. Estimated population near uranium tailings

    SciTech Connect

    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.

  8. Topological Signatures for Population Admixture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Topological Signatures for Population AdmixtureDeniz Yorukoglu1, Filippo Utro1, David Kuhn2, Saugata Basu3 and Laxmi Parida1* Abstract Background: As populations with multi-linear transmission (i.e., mixing of genetic material from two parents, say) evolve over generations, the genetic transmission...

  9. Population Growth: Stretching the Limits.

    ERIC Educational Resources Information Center

    Brouse, Deborah E.

    1990-01-01

    Three population education activities that can be used to illustrate the effects of uncontrolled population growth are presented. Included are "Crowding Can Be Seedy," which uses seeds; "Something for Everyone," which illustrates competition for resources; and "More or Less," which illustrates the relationship between humans and the environment.…

  10. Population. Global Issues Education Packet.

    ERIC Educational Resources Information Center

    Holm, Amy E.

    One of the most critical issues that faces humanity is the world population boom. The high rate of population growth can directly affect sensitive issues such as the state of the environment, economic development, health, resource uses, and consumption. Though we have achieved the capability to override many of nature's limitations, we live in a…

  11. Population Control and Scientific Ethics.

    ERIC Educational Resources Information Center

    Stern, Zev

    1978-01-01

    Garrett Hardin, a trained biologist, made a plea for coercive population control in a prestigious scientific journal (Science, 1968). His theory on how to control population is examined, the net effects of a situational vs an absolute ethics is weighed, and the limits to science and its methodology are evaluated. (Author/RK)

  12. Ten Charming Delusions About Population

    ERIC Educational Resources Information Center

    Hardin, Garrett

    1975-01-01

    Presents an open ended list of delusions about population which are based on expansionist economics and contends that dispelling these delusions, and others, will allow us to come to grip with the population problem. Some of the delusions presented concern birth control, sharing the wealth, and energy shortages. (BR)

  13. Information, Education, Communication in Population.

    ERIC Educational Resources Information Center

    Hawaii Univ., Honolulu. East-West Center.

    Programs and services of the Swedish International Development Authority (SIDA) are reviewed in this report on resources available for the support of population information, education, and communication activities. Four major sections describe in concise, outline form: (1) the agency and its programs, (2) the specific program in population/family…

  14. A Discussion of Population Invariance

    ERIC Educational Resources Information Center

    Brennan, Robert L.

    2008-01-01

    The discussion here covers five articles that are linked in the sense that they all treat population invariance. This discussion of population invariance is a somewhat broader treatment of the subject than simply a discussion of these five articles. In particular, occasional reference is made to publications other than those in this issue. The…

  15. Population Growth: Crisis and Challenge.

    ERIC Educational Resources Information Center

    Beaton, John R., Ed.; Doberenz, Alexander R., Ed.

    The proceedings of this first annual symposium on population growth considers the consequences of this growth, along with possible means of regulation. Topics of speeches include: Population Outlook in Asia (Irene Taeuber); Malnutrition is a Problem of Ecology (Paul Gyorgy); The Leisure Explosion (E. H. Storey); Effects of Pollution on Population…

  16. A Population Health Surveillance Theory

    PubMed Central

    Bigras-Poulin, Michel; Michel, Pascal; Ravel, André

    2012-01-01

    OBJECTIVES Despite its extensive use, the term "Surveillance" often takes on various meanings in the scientific literature pertinent to public health and animal health. A critical appraisal of this literature also reveals ambiguities relating to the scope and necessary structural components underpinning the surveillance process. The authors hypothesized that these inconsistencies translate to real or perceived deficiencies in the conceptual framework of population health surveillance. This paper presents a population health surveillance theory framed upon an explicit conceptual system relative to health surveillance performed in human and animal populations. METHODS The population health surveillance theory reflects the authors' system of thinking and was based on a creative process. RESULTS Population health surveillance includes two broad components: one relating to the human organization (which includes expertise and the administrative program), and one relating to the system per se (which includes elements of design and method) and which can be viewed as a process. The population health surveillance process is made of five sequential interrelated steps: 1) a trigger or need, 2) problem formulation, 3) surveillance planning, 4) surveillance implementation, and 5) information communication and audit. CONCLUSIONS The population health surveillance theory provides a systematic way of understanding, organizing and evaluating the population health surveillance process. PMID:23251837

  17. Play Therapy with Special Populations.

    ERIC Educational Resources Information Center

    Carmichael, Karla D.

    This paper notes that therapists often feel unqualified to deal with special populations of children because of a lack of understanding of the universalness of play therapy. Suggestions are offered for beginning play therapists who may work with a number of special populations of children. It is recommended that the social learning approach to…

  18. U.S. Population Growth.

    ERIC Educational Resources Information Center

    Dillner, Harry

    This autoinstructional lesson deals with the study of man and his environment. No previous experience or learning in this field is required. Emphasis is placed on analysis of population growth and the impact population growth and trends have on natural resource depletion. The behavioral objectives (five) are listed. The study guide for the…

  19. Paths for Future Population Aging.

    ERIC Educational Resources Information Center

    Grigsby, Jill S.

    Population aging refers to an entire age structure becoming older. The age structure of a population is the result of three basic processes: fertility, mortality, and migration. Age structures reflect both past effects and current patterns of these processes. At the town, city, or regional level, migration becomes an important factor in raising…

  20. Population and policy in Finland.

    PubMed

    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

  1. Information Networking in Population Education.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Bangkok (Thailand). Regional Office for Education in Asia and the Pacific.

    The rapidly increasing body of knowledge in population education has created the need for systematic and effective information services. Information networking entails sharing resources so that the information needs of all network participants are met. The goals of this manual are to: (1) instill in population education specialists a more…

  2. Energy demand and population changes

    SciTech Connect

    Allen, E.L.; Edmonds, J.A.

    1980-12-01

    Since World War II, US energy demand has grown more rapidly than population, so that per capita consumption of energy was about 60% higher in 1978 than in 1947. Population growth and the expansion of per capita real incomes have led to a greater use of energy. The aging of the US population is expected to increase per capita energy consumption, despite the increase in the proportion of persons over 65, who consume less energy than employed persons. The sharp decline in the population under 18 has led to an expansion in the relative proportion of population in the prime-labor-force age groups. Employed persons are heavy users of energy. The growth of the work force and GNP is largely attributable to the growing participation of females. Another important consequence of female employment is the growth in ownership of personal automobiles. A third factor pushing up labor-force growth is the steady influx of illegal aliens.

  3. Population control in symbiotic corals

    SciTech Connect

    Falkowski, P.G. ); Dubinsky, Z. ); Muscatine, L. ); McCloskey, L. )

    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.

  4. Capital, population and urban patterns.

    PubMed

    Zhang, W

    1994-04-01

    The author develops an approach to urban dynamics with endogenous capital and population growth, synthesizing the Alonso location model, the two-sector neoclassical growth model, and endogenous population theory. A dynamic model for an isolated island economy with endogenous capital, population, and residential structure is developed on the basis of Alonso's residential model and the two-sector neoclassical growth model. The model describes the interdependence between residential structure, economic growth, population growth, and economic structure over time and space. It has a unique long-run equilibrium, which may be either stable or unstable, depending upon the population dynamics. Applying the Hopf theorem, the author also shows that when the system is unstable, the economic geography exhibits permanent endogenous oscillations. PMID:12346957

  5. AFib in special populations.

    PubMed

    French, William J

    2014-04-01

    CHF has not been seen for patients with CHF and concomitant AFib, meaning that even with optimal therapy, the patient with AFib who develops CHF is at higher risk of mortality. The challenge for patients with ACS and AFib is that their ACS will probably require antiplatelet therapy, and addition of anticoagulation therapy as prophylaxis against stroke and systemic embolism because of the AFib creates the problem of so-called "triple therapy." This review includes a clinical decision algorithm for balancing the lowest risk of thromboembolic events against the highest risk of bleeding in patients who must receive triple therapy. Finally, this review concludes with a brief overview of the possible benefits of the NOACs in these populations, while also emphasizing that all clinicians-especially primary care physicians, who may become the principal caregivers for these patients with AFib in the era of NOACs-should be familiar with one of current bleeding scores, perhaps the best of which is the HAS-BLED score, which includes patients who have hypertension, abnormal renal or liver function, bleeding history, predisposition or labile INR, elderly patients who are frail or >65 years, or with a history of drugs/alcohol concomitantly. PMID:24655745

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

    PubMed

    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. [From population genetics to population genomics of forest trees: integrated population genomics approach].

    PubMed

    Krutovskiĭ, K V

    2006-10-01

    Early works by Altukhov and his associates on pine and spruce laid the foundation for Russian population genetic studies on tree species with the use of molecular genetic markers. In recent years, these species have become especially popular as nontraditional eukaryotic models for population and evolutionary genomic research. Tree species with large, cross-pollinating native populations, high genetic and phenotypic variation, growing in diverse environments and affected by environmental changes during hundreds of years of their individual development, are an ideal model for studying the molecular genetic basis of adaptation. The great advance in this field is due to the rapid development of population genomics in the last few years. In the broad sense, population genomics is a novel, fast-developing discipline, combining traditional population genetic approaches with the genomic level of analysis. Thousands of genes with known function and sometimes known genomic localization can be simultaneously studied in many individuals. This opens new prospects for obtaining statistical estimates for a great number of genes and segregating elements. Mating system, gene exchange, reproductive population size, population disequilibrium, interaction among populations, and many other traditional problems of population genetics can be now studied using data on variation in many genes. Moreover, population genomic analysis allows one to distinguish factors that affect individual genes, alleles, or nucleotides (such as, for example, natural selection) from factors affecting the entire genome (e.g., demography). This paper presents a brief review of traditional methods of studying genetic variation in forest tree species and introduces a new, integrated population genomics approach. The main stages of the latter are : (1) selection of genes, which are tentatively involved in variation of adaptive traits, by means of a detailed examination of the regulation and the expression of

  8. Tibet's population: past and present.

    PubMed

    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. PMID:12321528

  9. The Hispanic Population in the United States: March 1989. Current Population Reports: Population Characteristics.

    ERIC Educational Resources Information Center

    del Pinal, Jorge H.; De Navas, Carmen

    1990-01-01

    This report presents data on the demographic, social, and economic characteristics of the U.S. Hispanic population. The Bureau of the Census collected this information in the March 1989 supplement to the Current Population Survey. Data on Hispanic households includes household composition, urban and rural residence, tenure, availability of…

  10. Population education in the schools.

    PubMed

    Sherris, J D; Quillin, W F

    1982-01-01

    Formal population education is designed to teach children in school about basic population issues and, in many cases, to encourage them eventually to have smaller families. Some programs include specific units on human reproduction and family planning, while others do not. National population education programs began during the 1970s in about a dozen countries, mainly in Asia. These include Bangladesh, India, Indonesia, South Korea, Malaysia, the Philippines, Sierra Leone, Sri Lanka, Singapore, Thailand, Egypt, Tunisia, and El Salvador. A strong case can be made for including an important contemporary issue like population in the school curriculum. Nevertheless, educational innovation is a difficult and long-term process. As a rule, it takes 5 to 10 years before new material can be fully incorporated in a school curriculum. Curriculum changes must be carefully planned, thousands of teachers trained, and appropriate materials prepared for classroom use. Moreover, differences of opinion over the need, acceptability, goals, content, methods, and other aspects of population education have held back programs in some countries. Where population education programs have been implemented, student knowledge of population issues increases, but it is not yet clear whether in-school education has a measurable impact on fertility-related attitudes or behavior. PMID:7043518

  11. Drug abuse in slum population

    PubMed Central

    Ghulam, Ram; Verma, Kamal; Sharma, Pankaj; Razdan, Monica; Razdan, Rahul Anand

    2016-01-01

    Substance abuse is an important health problem throughout the world including India, but prevalence and pattern of abuse varies from country to country and in different types of population. Slums have their own social and economic problems so that substance abuse may be different in this population and might be related with these problems. The aim of the present study was to study the prevalence and pattern substances in slum population. Prakash Chandra Sethi Nagar slum area of Indore district was selected for the purpose of this study. In first phase of the study, first a camp was organized to sensitize local leaders, key persons, and local inhabitants about drug abuse at Chandra Prakash Sethi Nagar. After that basic information was gathered with the key persons in Chandra Prakash Sethi Nagar. In second phase by house-to-house survey, all members of the family were interviewed in detail and information was recorded on semi-structured proforma. We observed prevalence rate of 560/1000 populations, 78.2% were males, 28.2% were females, and two-third abusers were laborers (72%). In order of frequency, tobacco was the most common substance abused in 53.9% population followed by gutka (nontobacco pan masala). Other drugs in order of frequency were alcohol 46.5%, cannabis 8.9%, opiates 4.9%, sedative and hypnotic 2.0%, solvents 1.0%, and cocaine in 0.1%. Slum population has higher prevalence rates than general population. PMID:26985110

  12. Drug abuse in slum population.

    PubMed

    Ghulam, Ram; Verma, Kamal; Sharma, Pankaj; Razdan, Monica; Razdan, Rahul Anand

    2016-01-01

    Substance abuse is an important health problem throughout the world including India, but prevalence and pattern of abuse varies from country to country and in different types of population. Slums have their own social and economic problems so that substance abuse may be different in this population and might be related with these problems. The aim of the present study was to study the prevalence and pattern substances in slum population. Prakash Chandra Sethi Nagar slum area of Indore district was selected for the purpose of this study. In first phase of the study, first a camp was organized to sensitize local leaders, key persons, and local inhabitants about drug abuse at Chandra Prakash Sethi Nagar. After that basic information was gathered with the key persons in Chandra Prakash Sethi Nagar. In second phase by house-to-house survey, all members of the family were interviewed in detail and information was recorded on semi-structured proforma. We observed prevalence rate of 560/1000 populations, 78.2% were males, 28.2% were females, and two-third abusers were laborers (72%). In order of frequency, tobacco was the most common substance abused in 53.9% population followed by gutka (nontobacco pan masala). Other drugs in order of frequency were alcohol 46.5%, cannabis 8.9%, opiates 4.9%, sedative and hypnotic 2.0%, solvents 1.0%, and cocaine in 0.1%. Slum population has higher prevalence rates than general population. PMID:26985110

  13. Can human populations be stabilized?

    NASA Astrophysics Data System (ADS)

    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.

  14. Modern population trends in Bangladesh.

    PubMed

    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

  15. Viral population estimation using pyrosequencing.

    PubMed

    Eriksson, Nicholas; Pachter, Lior; Mitsuya, Yumi; Rhee, Soo-Yon; Wang, Chunlin; Gharizadeh, Baback; Ronaghi, Mostafa; Shafer, Robert W; Beerenwinkel, Niko

    2008-04-01

    The diversity of virus populations within single infected hosts presents a major difficulty for the natural immune response as well as for vaccine design and antiviral drug therapy. Recently developed pyrophosphate-based sequencing technologies (pyrosequencing) can be used for quantifying this diversity by ultra-deep sequencing of virus samples. We present computational methods for the analysis of such sequence data and apply these techniques to pyrosequencing data obtained from HIV populations within patients harboring drug-resistant virus strains. Our main result is the estimation of the population structure of the sample from the pyrosequencing reads. This inference is based on a statistical approach to error correction, followed by a combinatorial algorithm for constructing a minimal set of haplotypes that explain the data. Using this set of explaining haplotypes, we apply a statistical model to infer the frequencies of the haplotypes in the population via an expectation-maximization (EM) algorithm. We demonstrate that pyrosequencing reads allow for effective population reconstruction by extensive simulations and by comparison to 165 sequences obtained directly from clonal sequencing of four independent, diverse HIV populations. Thus, pyrosequencing can be used for cost-effective estimation of the structure of virus populations, promising new insights into viral evolutionary dynamics and disease control strategies. PMID:18437230

  16. How Large Asexual Populations Adapt

    NASA Astrophysics Data System (ADS)

    Desai, Michael

    2007-03-01

    We often think of beneficial mutations as being rare, and of adaptation as a sequence of selected substitutions: a beneficial mutation occurs, spreads through a population in a selective sweep, then later another beneficial mutation occurs, and so on. This simple picture is the basis for much of our intuition about adaptive evolution, and underlies a number of practical techniques for analyzing sequence data. Yet many large and mostly asexual populations -- including a wide variety of unicellular organisms and viruses -- live in a very different world. In these populations, beneficial mutations are common, and frequently interfere or cooperate with one another as they all attempt to sweep simultaneously. This radically changes the way these populations adapt: rather than an orderly sequence of selective sweeps, evolution is a constant swarm of competing and interfering mutations. I will describe some aspects of these dynamics, including why large asexual populations cannot evolve very quickly and the character of the diversity they maintain. I will explain how this changes our expectations of sequence data, how sex can help a population adapt, and the potential role of ``mutator'' phenotypes with abnormally high mutation rates. Finally, I will discuss comparisons of these predictions with evolution experiments in laboratory yeast populations.

  17. Soviet Marxism and population policy.

    PubMed

    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

  18. Population demographics of two local South Carolina mourning dove populations

    USGS Publications Warehouse

    McGowan, D.P., Jr.; Otis, D.L.

    1998-01-01

    The mourning dove (Zenaida macroura) call-count index had a significant (P 2,300 doves and examined >6,000 individuals during harvest bag checks. An age-specific band recovery model with time- and area-specific recovery rates, and constant survival rates, was chosen for estimation via Akaike's Information Criterion (AIC), likelihood ratio, and goodness-of-fit criteria. After-hatching-year (AHY) annual survival rate was 0.359 (SE = 0.056), and hatching-year (HY) annual survival rate was 0.118 (SE = 0.042). Average estimated recruitment per adult female into the prehunting season population was 3.40 (SE = 1.25) and 2.32 (SE = 0.46) for the 2 study areas. Our movement data support earlier hypotheses of nonmigratory breeding and harvested populations in South Carolina. Low survival rates and estimated population growth rate in the study areas may be representative only of small-scale areas that are heavily managed for dove hunting. Source-sink theory was used to develop a model of region-wide populations that is composed of source areas with positive growth rates and sink areas of declining growth. We suggest management of mourning doves in the Southeast might benefit from improved understanding of local population dynamics, as opposed to regional-scale population demographics.

  19. Simulation of population growth and structure of the population

    NASA Astrophysics Data System (ADS)

    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.

  20. Identifying Frailty Among Vulnerable Populations

    PubMed Central

    Salem, Benissa E.; Nyamathi, Adeline; Phillips, Linda R.; Mentes, Janet; Sarkisian, Catherine; Brecht, Lynn

    2014-01-01

    Frailty is a significant public health issue which is experienced by homeless and other vulnerable adults; to date, a frailty framework has not been proposed to guide researchers who study this hard-to-reach population. The Frailty Framework among Homeless and other Vulnerable Populations (FFHVP) has been developed from empirical research and consultation with frailty experts in an effort to characterize antecedents, i.e. situational, health-related, behavioral, resource, biological, and environmental factors which contribute to physical, psychological and social frailty domains and impact adverse outcomes. As vulnerable populations continue to age, a greater understanding of frailty will enable the development of nursing interventions. PMID:24469090

  1. Critical masses: world population 1984.

    PubMed

    Ehrlich, A

    1984-01-01

    There have been several changes since the 1974 conference on population growth held in Bucharest, Romania. Global population has expanded by 800 million people, an increase of 20% over the 1974 figure. The good news is that the rate of population growth, expressed as a percentage and not in terms of the absolute numbers added per year, has begun to slacken because of declining birthrates in many countries. Yet, because of the momentum of population growth, the population of the world is destined to continue growing for a century or so. The recognition of rapid population growth as a hindrance to development in poor countries has increased markedly during the last decade. The presumption that the development process by itself can lower birthrates has proven oversimplified, but certain kinds of development--what demographers term "social development" -- apparently foster reductions in fertility and directly improve people's well-being. Prime factors of social development are education (especially for women); nutritional, health, and sanitation measures leading to increased life expectancy; and a vigorous family planning effort. Few developing countries are without a family planning program or a population policy of some kind, and some have achieved impressive success in reducing their rates of population growth. China is possible the best known example of this, having attracted considerable press attention for its "1 child family" policy. If during the last decade population pressures on resources and environment have became discernible in the US and other rich countries, they have reached tragic proportions in many poor countries. In 1974 the idea that widespread hunger in developing countries was a symptom of overpopulation was denounced, but a decade later the people in many poor countries have begun to recognize the connections among population growth, faltering food production, deterioration of lands, environmental degradation, and economic problems of many

  2. Population approaches to aquatic toxicology

    SciTech Connect

    Vinegar, M.B.

    1981-10-01

    Field studies in which age-specific survivorship and fecundity are measured can provide data for the validation of laboratory studies conducted to assess the effects of toxic materials on aquatic species. Comparison of the variability of age-specific survivorship and fecundity in polluted versus nonpolluted areas would provide insight into the consequences of pollution at the population level. Techniques which permit prediction of population structure and growth from age-specific survivorship and fecundity schedules are described. These techniques include the life table and the Leslie matrix. Examples of population studies in which these techniques may be applied are given.

  3. Arctic nesting geese: alaskan populations

    USGS Publications Warehouse

    Hupp, Jerry W.; Stehn, Robert A.; Ely, Craig R.; Derksen, Dirk V.

    1995-01-01

    While data for some areas are lacking, populations of greater white-fronted geese (Anser albifrons frontalis) and medium-sized Canada geese (Branta canadensis) in interior and northern Alaska appear stable or have increased (King and Derksen 1986). Although only a small number of lesser snow geese (Chen caerulescens caerulescens) nest in Alaska, substantial populations occur in Canada and Russia. Populations of Pacific black brant (B. bernicla nigricans), emperor geese (C. canagica), greater white-fronted geese, and cackling Canada geese (B.c. minima) on the Yukon-Kuskokwim Delta (YKD) of western Alaska have declined from their historical numbers and are the focus of special management efforts (USFWS 1989). In addition, populations of tule white-fronted geese (A.a. gambeli), Aleutian Canada geese (B.c. leucopareia), Vancouver Canada Geese (B.c. fulva), and dusky Canada geese (B.c. occidentalis) are of special concern because of their limited geographic distributions and small numbers.

  4. National workshop on population education.

    PubMed

    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

  5. Anomalous Growth of Aging Populations

    NASA Astrophysics Data System (ADS)

    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.

  6. Population Issues. Resources in Technology.

    ERIC Educational Resources Information Center

    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)

  7. India's population: second and growing.

    PubMed

    Visaria, P; Visaria, L

    1981-10-01

    Attention in this discussion of the population of India is directed to the following: international comparisons, population pressures, trends in population growth (interstate variations), sex ratio and literacy, urban-rural distribution, migration (interstate migration, international migration), fertility and mortality levels, fertility trends (birth rate decline, interstate fertility differentials, rural-urban fertility decline, fertility differentials by education and religion, marriage and fertility), mortality trends (mortality differentials, health care services), population pressures on socioeconomic development (per capita income and poverty, unemployment and employment, increasing foodgrain production, school enrollment shortfalls), the family planning program, implementing population policy statements, what actions would be effective, and goals and prospects for the future. India's population, a total of 684 million persons as of March 1, 1981, is 2nd only to the population of China. The 1981 population was up by 136 million persons, or 24.75%, over the 548 million enumerated in the 1971 census. For 1978, India's birth and death rates were estimated at 33.3 and 14.2/1000 population, down from about 41.1 and 18.9 during the mid-1960s. India's current 5-year plan has set a goal of a birth rate of 30/1000 population by 1985 and "replacement-level" fertility--about 2.3 births per woman--by 1996. The acceleration in India's population growth has come mainly in the past 3 decades and is due primarily to a decline in mortality that has markedly outstripped the fertility decline. The Janata Party which assumed government leadership in March 1977 did not dismantle the family planning program, but emphasis was shifted to promote family planning "without any compulsion, coercion or pressures of any sort." The policy statement stressed that efforts were to be directed towards those currently underserved, mainly in rural areas. Hard targets were rejected. Over the 1978

  8. Effective sizes for subdivided populations.

    PubMed

    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

  9. Strategy selection in structured populations

    PubMed Central

    Tarnita, Corina E.; Ohtsuki, Hisashi; Antal, Tibor; Fu, Feng; Nowak, Martin A.

    2009-01-01

    Evolutionary game theory studies frequency dependent selection. The fitness of a strategy is not constant, but depends on the relative frequencies of strategies in the population. This type of evolutionary dynamics occurs in many settings of ecology, infectious disease dynamics, animal behavior and social interactions of humans. Traditionally evolutionary game dynamics are studied in well-mixed populations, where the interaction between any two individuals is equally likely. There have also been several approaches to study evolutionary games in structured populations. In this paper we present a simple result that holds for a large variety of population structures. We consider the game between two strategies, A and B, described by the payoff matrix (abcd). We study a mutation and selection process. If the payoffs are linear in a, b, c, d, then for weak selection strategy A is favored over B if and only if σa + b > c + σd. This means the effect of population structure on strategy selection can be described by a single parameter, σ. We present the values of σ for various examples including the well-mixed population, games on graphs and games in phenotype space. We give a proof for the existence of such a σ, which holds for all population structures and update rules that have certain (natural) properties. We assume weak selection, but allow any mutation rate. We discuss the relationship between σ and the critical benefit to cost ratio for the evolution of cooperation. The single parameter, σ, allows us to quantify the ability of a population structure to promote the evolution of cooperation or to choose efficient equilibria in coordination games. PMID:19358858

  10. Canada's population: growth and dualism.

    PubMed

    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. PMID:12335577

  11. Strategy selection in structured populations.

    PubMed

    Tarnita, Corina E; Ohtsuki, Hisashi; Antal, Tibor; Fu, Feng; Nowak, Martin A

    2009-08-01

    Evolutionary game theory studies frequency dependent selection. The fitness of a strategy is not constant, but depends on the relative frequencies of strategies in the population. This type of evolutionary dynamics occurs in many settings of ecology, infectious disease dynamics, animal behavior and social interactions of humans. Traditionally evolutionary game dynamics are studied in well-mixed populations, where the interaction between any two individuals is equally likely. There have also been several approaches to study evolutionary games in structured populations. In this paper we present a simple result that holds for a large variety of population structures. We consider the game between two strategies, A and B, described by the payoff matrix(abcd). We study a mutation and selection process. For weak selection strategy A is favored over B if and only if sigma a+b>c+sigma d. This means the effect of population structure on strategy selection can be described by a single parameter, sigma. We present the values of sigma for various examples including the well-mixed population, games on graphs, games in phenotype space and games on sets. We give a proof for the existence of such a sigma, which holds for all population structures and update rules that have certain (natural) properties. We assume weak selection, but allow any mutation rate. We discuss the relationship between sigma and the critical benefit to cost ratio for the evolution of cooperation. The single parameter, sigma, allows us to quantify the ability of a population structure to promote the evolution of cooperation or to choose efficient equilibria in coordination games. PMID:19358858

  12. Range Expansion of Heterogeneous Populations

    NASA Astrophysics Data System (ADS)

    Reiter, Matthias; Rulands, Steffen; Frey, Erwin

    2014-04-01

    Risk spreading in bacterial populations is generally regarded as a strategy to maximize survival. Here, we study its role during range expansion of a genetically diverse population where growth and motility are two alternative traits. We find that during the initial expansion phase fast-growing cells do have a selective advantage. By contrast, asymptotically, generalists balancing motility and reproduction are evolutionarily most successful. These findings are rationalized by a set of coupled Fisher equations complemented by stochastic simulations.

  13. Population Association of China (PAC).

    PubMed

    Xiong, Y

    1983-12-01

    In the past 3 years, the Population Association of China, an independent, academic, and nongovernment organization established in February 1981, organized demographers throughout China to tackle the population problems that emerged in the course of the nation's socioeconomic development. Thus, by organizing and promoting exchanges, the Association did help to push forward the vigorous development of population science. Now PAC has over 500 individuals and organized units as members. It has 90 council members and 19 permanent council members. Its annual tasks and research priorities are discussed and decided by the permanent council, and then implemented in various departments and localities by its council or association members. The Population Association has organized various academic activities among demographers to study the characteristics of different periods. 1983 is an important year for the reform of social and economic systems in China. The new situation and problems brought about by the reform are bound to affect the control of population growth. Consequently, the Association decided to emphasize the control of population growth in rural areas. At the same time, the Association advocated a style of study which required people to delve into the realities of life and to investigate and study these realities thoroughly. For this purpose, 3 discussions were either financed or authorized by the Association in a single year. At the symposiums, demographers and field workers, proceeding from their country's reality and by applying the Marxist point of view, tried to find effective solutions to the demographic problems. As a result, they produced a number of valuable academic reports. In the last few years, PAC played an important role in international academic activities and exchanges. Reviewing the past and looking ahead to the future, PAC will further unite China's demographers to make new contributions to the development of the country's population science

  14. Light on population health status.

    PubMed Central

    Beyrer, K.; Brauer, G. W.; Fliedner, T. M.; Greiner, C.; Reischl, U.

    1999-01-01

    A new approach to illustrating and analysing health status is presented which allows comparisons of various aspects of health in a population at different times and in different populations during given periods. Both quantitative and qualitative elements can be represented, the impact of interventions can be monitored, and the extent to which objectives are achieved can be assessed. The practical application of the approach is demonstrated with reference to the health profiles to Tunisia in 1966 and 1994. PMID:10083719

  15. Evolutionary dynamics in structured populations

    PubMed Central

    Nowak, Martin A.; Tarnita, Corina E.; Antal, Tibor

    2010-01-01

    Evolutionary dynamics shape the living world around us. At the centre of every evolutionary process is a population of reproducing individuals. The structure of that population affects evolutionary dynamics. The individuals can be molecules, cells, viruses, multicellular organisms or humans. Whenever the fitness of individuals depends on the relative abundance of phenotypes in the population, we are in the realm of evolutionary game theory. Evolutionary game theory is a general approach that can describe the competition of species in an ecosystem, the interaction between hosts and parasites, between viruses and cells, and also the spread of ideas and behaviours in the human population. In this perspective, we review the recent advances in evolutionary game dynamics with a particular emphasis on stochastic approaches in finite sized and structured populations. We give simple, fundamental laws that determine how natural selection chooses between competing strategies. We study the well-mixed population, evolutionary graph theory, games in phenotype space and evolutionary set theory. We apply these results to the evolution of cooperation. The mechanism that leads to the evolution of cooperation in these settings could be called ‘spatial selection’: cooperators prevail against defectors by clustering in physical or other spaces. PMID:20008382

  16. Natural Selection in Large Populations

    NASA Astrophysics Data System (ADS)

    Desai, Michael

    2011-03-01

    I will discuss theoretical and experimental approaches to the evolutionary dynamics and population genetics of natural selection in large populations. In these populations, many mutations are often present simultaneously, and because recombination is limited, selection cannot act on them all independently. Rather, it can only affect whole combinations of mutations linked together on the same chromosome. Methods common in theoretical population genetics have been of limited utility in analyzing this coupling between the fates of different mutations. In the past few years it has become increasingly clear that this is a crucial gap in our understanding, as sequence data has begun to show that selection appears to act pervasively on many linked sites in a wide range of populations, including viruses, microbes, Drosophila, and humans. I will describe approaches that combine analytical tools drawn from statistical physics and dynamical systems with traditional methods in theoretical population genetics to address this problem, and describe how experiments in budding yeast can help us directly observe these evolutionary dynamics.

  17. Evolutionary origins of invasive populations

    PubMed Central

    Lee, Carol Eunmi; Gelembiuk, Gregory William

    2008-01-01

    What factors shape the evolution of invasive populations? Recent theoretical and empirical studies suggest that an evolutionary history of disturbance might be an important factor. This perspective presents hypotheses regarding the impact of disturbance on the evolution of invasive populations, based on a synthesis of the existing literature. Disturbance might select for life-history traits that are favorable for colonizing novel habitats, such as rapid population growth and persistence. Theoretical results suggest that disturbance in the form of fluctuating environments might select for organismal flexibility, or alternatively, the evolution of evolvability. Rapidly fluctuating environments might favor organismal flexibility, such as broad tolerance or plasticity. Alternatively, longer fluctuations or environmental stress might lead to the evolution of evolvability by acting on features of the mutation matrix. Once genetic variance is generated via mutations, temporally fluctuating selection across generations might promote the accumulation and maintenance of genetic variation. Deeper insights into how disturbance in native habitats affects evolutionary and physiological responses of populations would give us greater capacity to predict the populations that are most likely to tolerate or adapt to novel environments during habitat invasions. Moreover, we would gain fundamental insights into the evolutionary origins of invasive populations. PMID:25567726

  18. Impact of population on adolescents.

    PubMed

    1997-01-01

    Adolescents are often overlooked in the efforts of developing countries to reduce population growth rates by lowering fertility and to care for aging populations in those countries that have been successful in reducing fertility. The September issue of the Asia-Pacific Population Journal contains an article by Professor Gavin Jones of the Australian National University entitled "Population Dynamics and Their Impact on Adolescents in the ESCAP Region," which overcomes that gap in information on the population aged 10-24. It examines aspects such as the growth of the adolescent population, age at marriage, educational developments, labor force participation, unemployment, and fertility among adolescents. The article concludes with an examination of the effects of demographic and educational changes, poverty, globalization, and urbanization on adolescents, drawing out a number of implications for policy purposes. Stating that most of today's adolescents will be still alive at mid-century, the article observes that "this cohort will play a crucial role in national development in an increasingly interconnected and high-technology world. From this perspective, it is tragic to note that many of these adolescents will still lack access to secondary schools--and in some cases, even to primary schooling--and will suffer from avoidable health problems." It also points out that, because adolescents greatly outnumber the elderly, care should be taken to ensure that policies towards them are not neglected. PMID:12321306

  19. Population priorities: the challenge of continued rapid population growth

    PubMed Central

    Turner, Adair

    2009-01-01

    Rapid population growth continues in the least developed countries. The revisionist case that rapid population could be overcome by technology, that population density was advantageous, that capital shallowing is not a vital concern and that empirical investigations had not proved a correlation between high population growth and low per capita income was both empirically and theoretically flawed. In the modern world, population density does not play the role it did in nineteenth-century Europe and rates of growth in some of today's least developed nations are four times than those in nineteenth-century Europe, and without major accumulation of capital per capita, no major economy has or is likely to make the low- to middle-income transition. Though not sufficient, capital accumulation for growth is absolutely essential to economic growth. While there are good reasons for objecting to the enforced nature of the Chinese one-child policy, we should not underestimate the positive impact which that policy has almost certainly had and will have over the next several decades on Chinese economic performance. And a valid reticence about telling developing countries that they must contain fertility should not lead us to underestimate the severely adverse impact of high fertility rates on the economic performance and prospects of many countries in Africa and the Middle East. PMID:19770149

  20. Population priorities: the challenge of continued rapid population growth.

    PubMed

    Turner, Adair

    2009-10-27

    Rapid population growth continues in the least developed countries. The revisionist case that rapid population could be overcome by technology, that population density was advantageous, that capital shallowing is not a vital concern and that empirical investigations had not proved a correlation between high population growth and low per capita income was both empirically and theoretically flawed. In the modern world, population density does not play the role it did in nineteenth-century Europe and rates of growth in some of today's least developed nations are four times than those in nineteenth-century Europe, and without major accumulation of capital per capita, no major economy has or is likely to make the low- to middle-income transition. Though not sufficient, capital accumulation for growth is absolutely essential to economic growth. While there are good reasons for objecting to the enforced nature of the Chinese one-child policy, we should not underestimate the positive impact which that policy has almost certainly had and will have over the next several decades on Chinese economic performance. And a valid reticence about telling developing countries that they must contain fertility should not lead us to underestimate the severely adverse impact of high fertility rates on the economic performance and prospects of many countries in Africa and the Middle East. PMID:19770149

  1. We must tackle population problems.

    PubMed

    Hironaka, W

    1992-03-01

    Thank you Mr. Chairman, for the opportunity to speak out not only as a Japanese parliamentarian, but also as a member of GLOBE International, Global Legislators Organization for a Balanced Environment, consisting of legislators from the US Congress, EC Parliament, USSR Assembly and Japanese Diet who have joined together to compare, improve and coordinate our respective legislative activities in an effort to effectively address the complex issues surrounding environment and development. Mr. Chairman, world population--which reached 5.4 billion in mid-1991--is growing exponentially. According to 1 UNFPA report 3 people are born every second, a total of 250,000 people every day or 95-100 million people every year. At this rate, world population will reach 6.4 billion by year 2001, and if this rate continues to go unchecked, world population will reach 14-15 billion by the end of the 21st century. GLOBE is highly aware of the relationship between rapidly growing human populations, environmental degradation and sustainable development. We urge UNCED negotiators to address population growth rates and the integrally linked concerns of resource consumption levels, particularly in the industrialized world, in their search for solutions to the conflict between environment and development. Negotiators should also seriously consider ways in which to broaden educational and economic opportunities for women to ease population growth rates, and to alleviate poverty and stresses on the environment that result from population pressures. Social and economic factors must be integrated into population planning. It is saddening to note that almost 40,000 children die every day due to malnutrition, lack of fresh water and access to resources. Over 100 million children do not receive a primary education. Mr. Chairman, worldwide demand for a range of family planning services is increasing faster than supply. Recent studies indicate that if quality family planning information, training and

  2. A Population Shift between Sparsely Populated Folding Intermediates Determines Amyloidogenicity.

    PubMed

    Karamanos, Theodoros K; Pashley, Clare L; Kalverda, Arnout P; Thompson, Gary S; Mayzel, Maxim; Orekhov, Vladislav Y; Radford, Sheena E

    2016-05-18

    The balance between protein folding and misfolding is a crucial determinant of amyloid assembly. Transient intermediates that are sparsely populated during protein folding have been identified as key players in amyloid aggregation. However, due to their ephemeral nature, structural characterization of these species remains challenging. Here, using the power of nonuniformly sampled NMR methods we investigate the folding pathway of amyloidogenic and nonamyloidogenic variants of β2-microglobulin (β2m) in atomic detail. Despite folding via common intermediate states, we show that the decreased population of the aggregation-prone ITrans state and population of a less stable, more dynamic species ablate amyloid formation by increasing the energy barrier for amyloid assembly. The results show that subtle changes in conformational dynamics can have a dramatic effect in determining whether a protein is amyloidogenic, without perturbation of the mechanism of protein folding. PMID:27117876

  3. The Inbreeding Effective Population Number in Dioecious Populations

    PubMed Central

    Nagylaki, T.

    1995-01-01

    The inbreeding effective population number in a dioecious population with discrete, nonoverlapping generations is investigated for both autosomal and X-linked loci. The recursion relations for the probabilities of genic identity and the effective population numbers are analyzed and compared in two cases: (i) the offspring identified by sex in the calculation of the probability of common parentage and (ii) the offspring not so identified. Case i gives the correct evolution of the probabilities of identity, but case ii has been more widely studied and applied. A general symmetric framework that reduces the number of parameters is developed and used to examine a wide variety of models of panmixia and monogamy. Cases i and ii agree in many, but not all, models. PMID:7705648

  4. A Population Shift between Sparsely Populated Folding Intermediates Determines Amyloidogenicity

    PubMed Central

    2016-01-01

    The balance between protein folding and misfolding is a crucial determinant of amyloid assembly. Transient intermediates that are sparsely populated during protein folding have been identified as key players in amyloid aggregation. However, due to their ephemeral nature, structural characterization of these species remains challenging. Here, using the power of nonuniformly sampled NMR methods we investigate the folding pathway of amyloidogenic and nonamyloidogenic variants of β2-microglobulin (β2m) in atomic detail. Despite folding via common intermediate states, we show that the decreased population of the aggregation-prone ITrans state and population of a less stable, more dynamic species ablate amyloid formation by increasing the energy barrier for amyloid assembly. The results show that subtle changes in conformational dynamics can have a dramatic effect in determining whether a protein is amyloidogenic, without perturbation of the mechanism of protein folding. PMID:27117876

  5. Effective sizes for subdivided populations

    SciTech Connect

    Chesser, R.K. Univ. of Georgia, Athens, GA ); Rhodes, O.E. Jr.; 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 size, 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 rates.

  6. Population in Advanced Placement Human Geography.

    ERIC Educational Resources Information Center

    Sharma, Martha B.

    2000-01-01

    Addresses the population section of the Advanced Placement course outline for human geography, focusing on four themes: (1) geographical analysis of population; (2) population distribution and composition; (3) population growth and decline over time and space; and (4) population movement. Identifies strategies for instructional activities.…

  7. Popullution: A Position Paper on Population.

    ERIC Educational Resources Information Center

    Durner, Mary Beth

    This position paper presents an interdisciplinary approach to the study of population. Six main sections are included in the paper: Introduction, The Growth of the Human Population, The Psychological Effects of Population Growth, Overpopulated America, Myths Concerning Population Growth and Control, and Population Education. Section 1, an…

  8. Population growth and economic growth.

    PubMed

    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

  9. Political economy of population growth.

    PubMed

    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. PMID:12179026

  10. Population policy: major party positions.

    PubMed

    Betts, K

    1998-01-01

    This article identifies the major political party positions on population policy (PP) in Australia. Australia has the Governing Coalition, comprised of the Liberal and National Parties, and the Australian Labor Party (ALP), the main opposition party. The ALP adopted a PP at its national conference in 1998. The Government Minister for Immigration and Multicultural Affairs (DIMA) does not view a PP as a need. The ALP policy identifies the need to decide on a long term sustainable population size as determined within a PP framework. The visa classification system needs to reflect national priorities. Labor will support a fair refugee and humanitarian program. Skilled labor migration must be linked with labor market needs. Business migration is a means of transferring resources and technology to Australia. The DIMA Minister announced the target intake of 80,000 visa immigrants in 1998- 99, which would produce a peak population of about 23 million in 2050. Settler arrivals from New Zealand would increase population size. A group of scientists and scholars published their recommendations about development of a PP. The Minister of DIMA's defense of the lack of a PP is included in this publication. Labor in several publications indicates support for a larger immigration intake, or an adjustment of the intake within the existing numbers. The Prime Minister, who supports the concept of multiculturalism, argues that people must accept immigration policy. Politics today are more divided over the origin and future of the nation than population size issues. PMID:12294231

  11. Global earthquake fatalities and population

    USGS Publications Warehouse

    Holzer, Thomas L.; Savage, James C.

    2013-01-01

    Modern global earthquake fatalities can be separated into two components: (1) fatalities from an approximately constant annual background rate that is independent of world population growth and (2) fatalities caused by earthquakes with large human death tolls, the frequency of which is dependent on world population. Earthquakes with death tolls greater than 100,000 (and 50,000) have increased with world population and obey a nonstationary Poisson distribution with rate proportional to population. We predict that the number of earthquakes with death tolls greater than 100,000 (50,000) will increase in the 21st century to 8.7±3.3 (20.5±4.3) from 4 (7) observed in the 20th century if world population reaches 10.1 billion in 2100. Combining fatalities caused by the background rate with fatalities caused by catastrophic earthquakes (>100,000 fatalities) indicates global fatalities in the 21st century will be 2.57±0.64 million if the average post-1900 death toll for catastrophic earthquakes (193,000) is assumed.

  12. The Why and How of Population Education

    ERIC Educational Resources Information Center

    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)

  13. ARIZONA CITIES WITH 1990 & 2000 POPULATION TOTALS

    EPA Science Inventory

    Point locations represent cities with Census 2000 population totals and 1990 Census population totals. Cities represent Census Designated Place (CDP) as classified by the US Bureau of the Census. CDP comprise densely settled concentrations of population that are identifiable by...

  14. HAWAII CITIES WITH 1990 & 2000 POPULATION TOTALS

    EPA Science Inventory

    Point locations represent cities with Census 2000 population totals and 1990 Census population totals. Cities represent Census Designated Place (CDP) as classified by the US Bureau of the Census. CDP comprise densely settled concentrations of population that are identifiable by...

  15. CALIFORNIA CITIES WITH 1990 & 2000 POPULATION TOTALS

    EPA Science Inventory

    Point locations represent cities with Census 2000 population totals and 1990 Census population totals. Cities represent Census Designated Place (CDP) as classified by the US Bureau of the Census. CDP comprise densely settled concentrations of population that are identifiable by...

  16. NEVADA CITIES WITH 1990 & 2000 POPULATION TOTALS

    EPA Science Inventory

    Point locations represent cities with Census 2000 population totals and 1990 Census population totals. Cities represent Census Designated Place (CDP) as classified by the US Bureau of the Census. CDP comprise densely settled concentrations of population that are identifiable by...

  17. Target population for clinical trials

    PubMed Central

    Studenski, S

    2016-01-01

    The target population for clinical trials aimed at sarcopenia depends on the goals of treatment and the expected natural history of sarcopenia. Based on a natural history where loss of muscle mass and/or quality leads to loss of strength, and eventually to reduced mobility and functional dependence, treatment goals can be defined for both preventive and therapeutic interventions. For example, a target population with low muscle mass and poor strength could be treated to prevent the onset of mobility disability, or a target population with low muscle mass and poor strength with mobility disability could be treated therapeutically to improve mobility. Eligibility for a trial should also be based on careful consideration of factors that affect 1) the ability to respond to treatment, 2) the safety of treatment, 3) expected prevalence and 4) feasibility. PMID:19657558

  18. Future directions in population health.

    PubMed

    Hancock, T

    1999-01-01

    The long-term health of the population will be influenced by a number of major forces in the next century. In this brief review, particular emphasis is placed on environmental and economic forces. Major global environmental changes include climate change and global warming, resource depletion, ecotoxicity and reduced biodiversity. We do not yet know the impact on longevity of lifetime exposure to a mix of persistent toxic chemicals in our environment, since it has only been widespread in the past 40-50 years. The health impacts of global warming are only just beginning to be understood and could be profound. But perhaps the most profound threat to population health is economic growth, to the extent that it undermines environmental and social sustainability. We need a new form of capitalism, one that simultaneously increases environmental, social, economic and human capital, if population health is to be maintained in the 21st century. PMID:10686767

  19. Complicated grief in Aboriginal populations

    PubMed Central

    Spiwak, Rae; Sareen, Jitender; Elias, Brenda; Martens, Patricia; Munro, Garry; Bolton, James

    2012-01-01

    To date there have been no studies examining complicated grief (CG) in Aboriginal populations. Although this research gap exists, it can be hypothesized that Aboriginal populations may be at increased risk for CG, given a variety of factors, including increased rates of all-cause mortality and death by suicide. Aboriginal people also have a past history of multiple stressors resulting from the effects of colonization and forced assimilation, a significant example being residential school placement. This loss of culture and high rates of traumatic events may place Aboriginal individuals at increased risk for suicide, as well as CG resulting from traumatic loss and suicide bereavement. Studies are needed to examine CG in Aboriginal populations. These studies must include cooperation with Aboriginal communities to help identify risk factors for CG, understand the role of culture among these communities, and identify interventions to reduce poor health outcomes such as suicidal behavior. PMID:22754293

  20. Rhinitis in the geriatric population

    PubMed Central

    2010-01-01

    The current geriatric population in the United States accounts for approximately 12% of the total population and is projected to reach nearly 20% (71.5 million people) by 2030[1]. With this expansion of the number of older adults, physicians will face the common complaint of rhinitis with increasing frequency. Nasal symptoms pose a significant burden on the health of older people and require attention to improve quality of life. Several mechanisms likely underlie the pathogenesis of rhinitis in these patients, including inflammatory conditions and the influence of aging on nasal physiology, with the potential for interaction between the two. Various treatments have been proposed to manage this condition; however, more work is needed to enhance our understanding of the pathophysiology of the various forms of geriatric rhinitis and to develop more effective therapies for this important patient population. PMID:20465792

  1. Complicated grief in Aboriginal populations.

    PubMed

    Spiwak, Rae; Sareen, Jitender; Elias, Brenda; Martens, Patricia; Munro, Garry; Bolton, James

    2012-06-01

    To date there have been no studies examining complicated grief (CG) in Aboriginal populations. Although this research gap exists, it can be hypothesized that Aboriginal populations may be at increased risk for CG, given a variety of factors, including increased rates of all-cause mortality and death by suicide. Aboriginal people also have a past history of multiple stressors resulting from the effects of colonization and forced assimilation, a significant example being residential school placement. This loss of culture and high rates of traumatic events may place Aboriginal individuals at increased risk for suicide, as well as CG resulting from traumatic loss and suicide bereavement. Studies are needed to examine CG in Aboriginal populations. These studies must include cooperation with Aboriginal communities to help identify risk factors for CG, understand the role of culture among these communities, and identify interventions to reduce poor health outcomes such as suicidal behavior. PMID:22754293

  2. Genealogical histories in structured populations.

    PubMed

    Kumagai, Seiji; Uyenoyama, Marcy K

    2015-06-01

    In genealogies of genes sampled from structured populations, lineages coalesce at rates dependent on the states of the lineages. For migration and coalescence events occurring on comparable time scales, for example, only lineages residing in the same deme of a geographically subdivided population can have descended from a common ancestor in the immediately preceding generation. Here, we explore aspects of genealogical structure in a population comprising two demes, between which migration may occur. We use generating functions to obtain exact densities and moments of coalescence time, number of mutations, total tree length, and age of the most recent common ancestor of the sample. We describe qualitative features of the distribution of gene genealogies, including factors that influence the geographical location of the most recent common ancestor and departures of the distribution of internode lengths from exponential. PMID:25770971

  3. Population fluctuation in phytophagous insects

    SciTech Connect

    Redfearn, A.; Pimm, S.L. )

    1994-06-01

    We examined how community interactions affect year-to-year population variability in three groups of phytophagous insects: British aphids and moths, and Canadian moths. We first examined how the number of host plant species on which a given phytophagous insect species feeds affects its population variability. Specialist insect species showed a weak tendency to be more variable than generalist species. We then examined how the number of species of parasitoids from which a given phytophagous insects species suffers affects its population variability. Species that are host to few parasitoid species showed a weak tendency to be more variable than species with many parsitoid species. These relationships also depend on other aspects of the life histories of the phytophagous insect species.

  4. Amerciamysis bahia Stochastic Matrix Population Model for Laboratory Populations

    EPA Science Inventory

    The population model described here is a stochastic, density-independent matrix model for integrating the effects of toxicants on survival and reproduction of the marine invertebrate, Americamysis bahia. The model was constructed using Microsoft® Excel 2003. The focus of the mode...

  5. Literacy and World Population. Population Bulletin No. 2, Vol. 30.

    ERIC Educational Resources Information Center

    Population Reference Bureau, Inc., Washington, DC.

    This bulletin examines aspects of world literacy with regard to population projects and family planning. Discussion includes the presentation of perspectives, definitions, and statistics concerning literacy. The role of literacy in economic development is examined; specific topics include adult and school-age illiteracy, rural and urban…

  6. Population change and the environment.

    PubMed

    1989-01-01

    The environmental and natural resource problems that afflict most countries of the Asian and Pacific region are caused by human activities, often arising from the needs of growing populations for land to cultivate subsistence crops. These include the farming of marginal land; insufficient fallow periods; the clearing of forest land for agriculture and the felling of trees for firewood and timber. Water pollution, air pollution, deforestation and desertification are related to human activities. One of the priorities for population and development planning in the region will be action-oriented research into the linkages, to guide national and regional development policies. Both population and environmental concerns must be integrated into social and economic development plans in order for development to be sustainable. To achieve these goals, rapid population growth must be slowed and eventually stabilized, while strategies on optimal population distribution should be formulated. Concomitantly, environmental conditions must be maintained or improved through reversing deforestation and erosion in major watersheds; checking the spread of deserts; introducing sustainable water management; reducing acidification and hazardous waste; developing and introducing environmentally safe industrial processes; eliminating hunger through sustainable agriculture; finding new and renewable sources of energy and increasing energy efficiency; and protecting animal and plant species and preventing further loss. To avoid the possible negative consequences, balanced development in an integrated fashion is called for. As far as environmental problems are concerned, there is a growing need for the planning mechanism to take demographic variables into account in a more integrated way than has been done in the past. For purposes of environmental and population planning, a longer-term approach should be taken in addition to the five-year plans. PMID:12282459

  7. Integrated population and development planning.

    PubMed

    1987-01-01

    More and more developing countries are recognizing that high fertility and rapid population growth burden and delay economic and social progress. Relatively few have been able to analyze the complex effects that different rates of fertility and population growth have on education, health care, employment, housing, agriculture, and other sectors of their society. Several developing countries are being helped over these hurdles by the Integrated Population and Development Planning II project (INPLAN), a project carried out by the Research Triangle Institute (RTI) under a contract with the US Agency for International Development's Office of Population. INPLAN assistance usually begins with 2-week training courses held in developing countries. Participants learn practical ways to integrate population factors into their development planning. Microcomputer applications, including demographic-economic planning models, are emphasized. Once planners become familiar with microcomputers, INPLAN staff work with them to develop microcomputer-based planning models for their country. Models have been developed to evaluate the impact of population on a number of areas including education, employment, health services, food and agriculture, and the macroeconomy. Cost-benefit analysis models show that there have been very high returns to investments in national family planning programs. After a preliminary model is developed at RTI, it is demonstrated in the participating country. The model is then refined in a collaborative effort with the planners who use them. The goal is to leave planners with a model they are so familiar with that they can continue to use and modify it after INPLAN advisors have left. 300 people from 45 countries have been trained through INPLAN over the last 3 years. Besides developing models, INPLAN technical support includes the transfer and installation of microcomputer hardware and planning software, as well as training in their use. So far, 25 developing

  8. [Population growth and the environment].

    PubMed

    Hogan, D J

    1991-01-01

    The impact of population growth on the enviornment has been extensively researched; it consists of the depletion of resources (agricultural land absorbed by urban expansion, loss of soils, desertification, loss of biodiversity, less availability of minerals, dwindling of petroleum reserves) and the degradation of natural resources (air and water pollution). For politicians, journalists, and environmentalists, population growth is identified as the principal villain, which is a unidirectional and negative opinion. Demography is supposed to examine the negative and positive effects of the environment-population relationship; however, it is postulated that there has not been much produced in the last 2 centuries in this area. Examination of the research literature does not indicate any view that transcends the Malthusian vision, although a few empirical studies exist (Hogan, 1989). Durham (1979) identified the replacement of subsistence agriculture by export-oriented agriculture as the key factor in overpopulation in El Salvador and Honduras that led to migrations and international conflicts. Tudela (1987) related a similar process in the Mexican state of Tabasco, where a period of malnutrition was accompanied by the expansion of export agriculture and nutritional improvements emanated only from recapturing subsistence agriculture. Fearnside (1986) researched the dynamics of the occupation and destruction of Amazonia. However, Kahn and Simon went further and denied the existence of real environmental problems: population is the ultimate resource, and the more minds, the more good ideas and solutions for any problem. However, in all these cases of pure or modified Malthusianism the relation of population/resources is reduced to a unidimensional relationship; and fertility, mortality, migration, marriage, and age structure receive little attention. A prime candidate for the attention of population specialists should be migration and patterns of settlement and their

  9. Sweden's population grows, Swedish population doesn't.

    PubMed

    Gendell, M

    1984-03-01

    The example of Swedish demography offers a contemporary insight into population growth or decline. In addition to the numerical increase due to the arrival of immigrants, migration can have an indirect effect on a country's population growth due to the arrived immigrants' subsequent natural fertility. Some very interesting differences also can often be observed in the births and deaths between the native born and immigrant populations. This phenomenon is particularly striking in the case of Sweden. In 1970 Sweden's population was growing at nearly 1% per year (9.83/1000), a relatively rapid pace by today's standard. Since 1970, the growth rate dropped steadily, down to only 0.1% in 1981. The main reason for the slowed population growth has been the decline in the birthrate, from 14/1000 population to the 11.3-11.7 range since 1976. At the same time, the death rate rose from 10 to 11. Gains in life expectancy have been outweighed by the increasing proportion of the elderly. During the 1970s the rate of net migration fluctuated considerably. It dropped from a high rate of 6/1000 in 1970 to -1.5 in 1972. 1972 and 1973 are the only postwar years in which Sweden experienced a net outflow. The rate rose again to 2.89 in 1977, falling to 0.3 in 1981, the latest year for which data are available. Starting in 1975 the components of Sweden's population change began to exhibit a remarkable aspect: population growth due to migration exceeded that due to natural increase. This had not occurred previously. Close examination reveals that the gain due to natural increase had become dependent upon the natural increase of the immigrants. Births of Swedish citizens, which had exceeded deaths by 22,000 in 1971, fell until natural decrease appeared in 1976. That gap has been growing wider ever since, to -6100 in 1982. A growing number of immigrants have been attaining Swedish citizenship, but the category of "citizen" is still the virtual equivalent of "native born." At the end of 1981

  10. The population of small NEAs

    NASA Astrophysics Data System (ADS)

    Harris, Alan W.

    2014-11-01

    Every two years I re-assess the completion of NEA surveys and from that estimate the size-frequency distribution of NEAs, from the largest 10 km diameter) down to the smallest detected by surveys, only a few meters across. The number of large NEAs (D > 1 km) is by now well established at just under 1,000 objects, and not likely to be revised much. The greatest uncertainty lies in the smaller range, from ~100 m diameter down to about 10 m, below which bolide and meteor data yield more reliable numbers. Connecting the two in the mid-range has been a bit problematical. In this paper I will present new population estimates, concentrating in this size range, and propose a smoothed linkage between the survey estimated population at 100 m and above with the bolide estimated population at 10 m and smaller. I will also present an estimate of the population and survey completion of so-called ARM-target asteroids (D ~10 m, Earth encounter velocity < 2.6 km/sec, and MOID < 0.03 AU). I find that present ground-based surveys are surprisingly efficient detecting such objects, and that the 20 or so thus far found represent about 1% of the total population of a couple thousand. This result is consistent with the fact that of the 20 or so found, two are known to be re-discovered old rocket bodies, out of a total of about 100 such objects out there (we know the latter number because we put them there). Lastly, I will estimate the population expected of such low-v objects, based on diffusion from higher-v orbits and depletion by Earth collisions, to show that the ~2,000 population estimate is about what is expected in steady state. Larger populations could exist from time to time due to lunar ejecta launched into heliocentric orbits following major impact events on the moon. Such excesses would have a decay time scale of hundreds of thousands of years.

  11. Population education for social betterment.

    PubMed

    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

  12. The North Atlantic Population Project

    PubMed Central

    RUGGLES, STEVEN; ROBERTS, EVAN; SARKAR, SULA; SOBEK, MATTHEW

    2011-01-01

    The North Atlantic Population Project (NAPP) is a massive database of historical census microdata from European and North American countries. The backbone of the project is the unique collection of completely digitized censuses providing information on the entire enumerated populations of each country. In addition, for some countries, the NAPP includes sample data from surrounding census years. In this article, the authors provide a brief history of the project, describe their progress to data and plans for the future, and discuss some potential implications of this unique data resource for social and economic research. PMID:22199411

  13. Population ageing and dental care.

    PubMed

    Harford, Jane

    2009-04-01

    Population ageing is a fact in both developed and developing countries. The concern about population ageing largely arises from the combination of a greater number of older people requiring greater amounts of healthcare services and pensions, and relatively fewer people working to pay for them. Oral health and dental care are important aspects of health and health care. Lower rates of edentulism and an ageing population mean that older people will feature more prominently in dental services. Traditionally, economic studies of ageing have focused on the fiscal implications of ageing, projecting the increased burden on health and welfare services that accompanies ageing. It assumed that ageing is the major driver of recent changes and those past trends will simply be amplified by faster population ageing in the future. Less work has been done to understand other past drivers of increased healthcare spending and their implications for the future. The conclusion of these reports is usually that population ageing is unaffordable with current policy settings. They have proposed policies to deal with population ageing which focused on increasing workforce participation and worker productivity to increase the tax base and reducing entitlements. However, the affordability question is as much political as a numerical. There are no clearly articulated criteria for affordability and little opportunity for public discourse about what citizens are willing to pay in taxes to support an ageing population. While the reports do not necessarily reflect public opinion, they will certainly shape it. Predicting the future for oral health is more fraught than for general health, as oral health is in the midst of an epidemiological transition from high rates of edentulism and tooth loss to low rates. Changes in the pattern of dental expenditure in the past do not mirror the experience of rapid increases in per capita expenditure on older age groups as regards general health. Dentistry

  14. Evolutionary dynamics on interdependent populations

    NASA Astrophysics Data System (ADS)

    Gómez-Gardeñes, Jesús; Gracia-Lázaro, Carlos; Floría, Luis Mario; Moreno, Yamir

    2012-11-01

    Although several mechanisms can promote cooperative behavior, there is no general consensus about why cooperation survives when the most profitable action for an individual is to defect, especially when the population is well mixed. Here we show that when a replicator such as evolutionary game dynamics takes place on interdependent networks, cooperative behavior is fixed on the system. Remarkably, we analytically and numerically show that this is even the case for well-mixed populations. Our results open the path to mechanisms able to sustain cooperation and can provide hints for controlling its rise and fall in a variety of biological and social systems.

  15. The LMC Intermediate and Populations

    NASA Astrophysics Data System (ADS)

    Olszewski, E. W.

    I will discuss our current understanding of the intermediate and old populations of the LMC. Dominant themes will be what those populations tell us about the relative ages of the oldest components of the Milky Way and LMC, what they tell us about the star formation history of the LMC, and what they tell us about the presence or absence of a halo (as we understand that term in the Milky Way) in the LMC. Topics not discussed at previous Magellanic Cloud meetings include the ages of the oldest LMC clusters from HST data, and the seeming lack of agreement between deep luminosity function analyses and distributions of abundances of red giants.

  16. Managing Salmonella in equine populations.

    PubMed

    Burgess, Brandy A; Morley, Paul S

    2014-12-01

    Infection control is achieved through all efforts used to prevent the introduction and limit the spread of contagious pathogens within a facility or population, with the goal of eliminating sources of potentially pathogenic microorganisms and to disrupt infectious disease transmission. Congregating animals from multiple sources, as occurs at veterinary hospitals, racetracks, equestrian events, and boarding and training facilities, increases the risk for transmission of infectious diseases such as salmonella. There is a recognizable standard of practice for infection control and due effort must be given to control and prevention of infectious disease transmission within animal populations and facilities. PMID:25282320

  17. Population momentum: Implications for wildlife management

    USGS Publications Warehouse

    Koons, D.N.; Rockwell, R.F.; Grand, J.B.

    2006-01-01

    Maintenance of sustainable wildlife populations is one of the primary purposes of wildlife management. Thus, it is important to monitor and manage population growth over time. Sensitivity analysis of the long-term (i.e., asymptotic) population growth rate to changes in the vital rates is commonly used in management to identify the vital rates that contribute most to population growth. Yet, dynamics associated with the long-term population growth rate only pertain to the special case when there is a stable age (or stage) distribution of individuals in the population. Frequently, this assumption is necessary because age structure is rarely estimated. However, management actions can greatly affect the age distribution of a population. For initially growing and declining populations, we instituted hypothetical management targeted at halting the growth or decline of the population, and measured the effects of a changing age structure on the population dynamics. When we changed vital rates, the age structure became unstable and population momentum caused populations to grow differently than that predicted by the long-term population growth rate. Interestingly, changes in fertility actually reversed the direction of short-term population growth, leading to long-term population sizes that were actually smaller or larger than that when fertility was changed. Population momentum can significantly affect population dynamics and will be an important factor in the use of population models for management.

  18. Population transfer through the continuum

    SciTech Connect

    Nakajima, T.; Elk, M.; Zhang, J.; Lambropoulos, P. Foundation of Research and Technology Hellas, Institute of Electronic Structure and Laser and Department of Physics, University of Crete, P.O. Box 1527, Heraklion 711 10, Crete Department of Physics, University of Southern California, Los Angeles, California 90089-0484 )

    1994-08-01

    We show that complete population transfer is not in general possible through continuum intermediate states. We present a formal theoretical argument and supporting numerical results. In addition, the behavior of the system is compared with the well-known [Lambda] system.

  19. Modeling Population Growth and Extinction

    ERIC Educational Resources Information Center

    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,…

  20. Synthetic population system user guide

    SciTech Connect

    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.

  1. Doubling of world population unlikely.

    PubMed

    Lutz, W; Sanderson, W; Scherbov, S

    1997-06-19

    Most national and international agencies producing population projections avoid addressing explicitly the issue of uncertainty. Typically, they provide either a single projection or a set of low, medium and high variants, and only very rarely do they give these projections a probabilistic interpretation. Probabilistic population projections have been developed for specific industrialized countries, mostly the United States, and are based largely on time-series analysis. On a global level, time-series analysis is not applicable because there is a lack of appropriate data, and for conceptual reasons such as the structural discontinuity caused by the demographic transition. Here we report on a new probabilistic approach that makes use of expert opinion on trends in fertility, mortality and migration, and on the 90 per cent uncertainty range of those trends in different parts of the world. We have used simulation techniques to derive probability distributions of population sizes and age structures for 13 regions of the world up to the year 2100. Among other things, we find that there is a probability of two-thirds that the world's population will not double in the twenty-first century. PMID:9194559

  2. Energy demand and population change.

    PubMed

    Allen, E L; Edmonds, J A

    1981-09-01

    During the post World War 2 years energy consumption has grown 136% while population grew about 51%; per capita consumption of energy expanded, therefore, about 60%. For a given population size, demographic changes mean an increase in energy needs; for instance the larger the group of retirement age people, the smaller their energy needs than are those for a younger group. Estimates indicate that by the year 2000 the energy impact will be toward higher per capita consumption with 60% of the population in the 19-61 age group of workers. Rising female labor force participation will increase the working group even more; it has also been found that income and energy grow at a proportional rate. The authors predict that gasoline consumption within the US will continue to rise with availability considering the larger number of female drivers and higher per capita incomes. The flow of illegal aliens (750,000/year) will have a major impact on income and will use greater amounts of energy than can be expected. A demographic change which will lower energy demands will be the slowdown of the rate of household formation caused by the falling number of young adults. The response of energy demand to price changes is small and slow but incomes play a larger role as does the number of personal automobiles and social changes affecting household formation. Households, commercial space, transportation, and industry are part of every demand analysis and population projections play a major role in determining these factors. PMID:12265241

  3. Population Growth: Family Planning Programs.

    ERIC Educational Resources Information Center

    Doberenz, Alexander R., Ed.; Taylor, N. Burwell G., Ed.

    These proceedings of the second annual symposium on population growth bring together speeches and panel discussions on family planning programs. Titles of speeches delivered are: Communicating Family Planning (Mrs. Jean Hutchinson); Effects of New York's Abortion Law Change (Dr. Walter Rogers); The Law and Birth Control, Sterilization and Abortion…

  4. Population research potentials in Africa.

    PubMed

    Hyden, G

    1980-01-01

    There is a need in Africa to test prevailing theories and concepts in population studies to see how they apply to this culture. Most of the prevailing perspective on population issues can be influenced by development strategies and policies affecting demographic variables. So research designed to determine the longterm consequences of rural settlement policies on subsequent access to family planning or family planning policies are also needed, as are studies which zero in on the work and results of specific population projects. The following issues are considered worth special consideration in Africa, where the vast majority of women live in rural areas where family planning services will not reach for some time. The areas of investigation which seem most pertinent in sub-saharan Africa are: side effect of contraceptive devices and agents; infertility assessments, social and medical consequences of adolescent pregnancies, the means of offering effective population education in rural African areas, the possible effects of fertility control programs on demographic transition, and potential funding sources. PMID:12336771

  5. CURRENT POPULATION SURVEY NATIVITY SUPPLEMENT

    EPA Science Inventory

    The Current Population Survey (CPS) is a cross-sectional survey conducted with about 57,000 households every month, primarily to measure changes in the labor force. It is conducted by the U.S. Bureau of the Census and administered to panels of respondents, which revolve into the ...

  6. Nutrition, Development, and Population Growth

    ERIC Educational Resources Information Center

    Berg, Alan

    1973-01-01

    Focuses on the problem of malnutrition in developing countries through a description of its interrelationships with human development, national economies, economic growth and income, agricultural advances, the crisis in infant feeding practices, new foods, and the population dilemma. Outlines possible future policy directions to significantly…

  7. Flood trends and population dynamics

    NASA Astrophysics Data System (ADS)

    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.

  8. Population studies of Plasmodium vivax

    PubMed Central

    Rybalka, V. M.; Beljaev, A. E.; Lysenko, A. Ja.

    1977-01-01

    The authors investigate a mathematical model based on the theory they proposed in a previous publication. The model fits field data collected in re-established foci of tertian malaria. The patterns of distribution of manifestations of tertian malaria among the population may readily be explained on the basis of the theory of polymorphism of sporozoites. PMID:338189

  9. Genetic structure of forensic populations.

    PubMed Central

    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. PMID:1557360

  10. Genebanking seeds from natural populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. Populism and Education in Norway.

    ERIC Educational Resources Information Center

    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,…

  12. Populism in High School Textbooks

    ERIC Educational Resources Information Center

    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)

  13. Whither the global population problem.

    PubMed

    Greep, R O

    1998-02-15

    Growth of the human population has been underway for thousands of years and was never a problem until recently. It is now expanding exponentially, and today global population stands at nearly 6 billion with 97 million being added each year. Currently, overpopulation has led to serious social and environmental problems such as poverty, overcrowded slums, crime, terrorism, pollution of air and water, and depletion of the protective ozone layer. Warnings were sounded, but few listened. The enthusiasm once generated for solving the problem of too many people was short-lived. The press with puzzling abrogation of its responsibility to the public managed to allay all fears of population overgrowth. Two U.S. presidents welcomed such growth as a stimulus to economic development. Although modern contraceptives are safe, effective, and widely available, more are badly needed, but none are in the pipeline. Research is being hampered by hostile attitudes and by the high cost in time and money of bringing a new contraceptive to an uncertain market with the added threat of litigation. At the present rate of growth, the population will double in the next century. This is believed to be beyond the carrying capacity of our planet. Corrective measures by man or nature need to be undertaken. PMID:9514071

  14. The Middle East population puzzle.

    PubMed

    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

  15. Population and the Colombian economy.

    PubMed

    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

  16. [Comments on population and ecology].

    PubMed

    Negrette, J C

    1990-12-01

    Concern about the condition of the environment and about rapid population growth has a long history. The breadth and magnitude of present day concern may perhaps represent a new development even though the topics themselves are not new. There is almost no country or society that has not manifested disquiet about 1 or the other. Ecology in the strict sense is defined as the relationship between organisms and their environment. In recent decades ecology has come to understood as the manner of avoiding or slowing environmental deterioration or even as the correct and prudent administration of natural resources. The boundaries of the discipline have expanded until today it is concerned with various spheres of the natural and social sciences. The transformations wrought by human beings have been dramatic, both because the use of tools had increased the power of human modification of the environment and because the human population is large and spread over the whole world. Human beings have been responsible for some ecologic disasters, some unintentional like the Exxon Valdez and Chernobyl accidents and others the perhaps unforseen results of deliberate actions, as the contamination of the atmosphere with gas emissions. Environmental deterioration can result from numerous causes, as with the "greenhouse effect" caused by a range of factors including classical contamination and deforestation. Deforestation in developing countries is a response to the combination of poverty and rapid population growth, and is 1 evidence of the close and direct link between population growth and the condition of the environment. The optimism felt during the 1970s about the prospects of bringing world population growth under control has given way to a more realistic and sobering assessment. Many factors including widespread economic difficulties have impeded the progress of family planning programs. It is urgent that efforts to curb rapid population increase be intensified. 1 important means

  17. The population debate heats up.

    PubMed

    Malay, R L

    1994-01-01

    60% of the 65 million people in the Philippines have lived below the poverty line amid overall negative GNP growth for almost a decade. The population is growing at the annual rate of 2.4%. These conditions suggest the urgent need to reduce population growth and take measures to improve the performance of the economy. The big debate in the Philippines regarding population and development, however, is not over the redistribution of resources, but about the morality of managing population growth through the promotion of artificial means of contraception. Roman Catholicism predominates among religions in the Philippines. The Catholic Church in the Philippines, as elsewhere around the world, alleges that artificial contraceptives are abortifacient and that only natural methods should be promoted. Although Health Secretary Dr. Juan M. Flavier, a staunch supporter of family planning, points out that the church and state both abhor abortion, accept natural family planning, and would like to offer a better quality of life to the people, it is clear that the government does not agree with the Church's endorsement of only natural family planning methods. Surveys have found that most Filipinos agree with the government; they are in favor of family planning and feel that the Church should stay out of the debate. A people-centered approach to development and concern for the environment are called for to improve the Filipino quality of life. At the global level, the Vatican has allies among believers of Islam in its position against abortion and in favor of a traditional concept of the family. Despite wrangling at the International Conference on Population and Development (ICPD) over a woman's right to abortion and other contentious issues, such as the objection among Southern states to the ICPD committee's exclusion of the right to family reunification, the ICPD was a success because it gave prime importance to the link between population and sustainable development. The ICPD

  18. Population information activities in Hungary.

    PubMed

    Csahok, I

    1984-12-01

    The focal point for all population information activities in Hungary is the Central Statistical Office which is responsible for the organization and implementation of the decennial population censuses and of the intercensal population surveys and other data collection activities. The Central Statistical Office publishes a large volume of population information. The results of the censuses are presented partly in special census volumes and partly in statistical yearbooks. The Demographic Yearbook and other publications present results of population studies and Hungarian statistics. The Demographic Research Institute, which is part of the Central Statistical Office, is primarily responsible for research activity. The main task of the Institute is to study and analyze population processes and phenomena, as well as explore main demographic trends, carried out by using Hungarian and international demographic data. Demografia and serial publications present results of research activities of the Institute. The Library and Documentation Service, also part of the Central Statistical Office, provides conventional library services. Its main activity is the collection of both Hungarian and foreign and international official statistical publications, as well as theoretical and methodological works. Of a stock of 650,000 volumes covering a wide range of social and economic sciences, in addition to data material, the library has nearly 120,000 official statistical publications consisting mainly of population statistics and demographic data. Another activity of the Library is the processing and dissemination of documentation and it acts as a 2dary source of both Hungarian and foreign publications, especially on demography. The documentation consists of translating articles, book chapters or documents of international organizations, editing annotated bibliographies and disseminating custom-made, user-oriented profiles. This computerized information retrieval system uses Text

  19. Extinction of metastable stochastic populations.

    PubMed

    Assaf, Michael; Meerson, Baruch

    2010-02-01

    We investigate the phenomenon of extinction of a long-lived self-regulating stochastic population, caused by intrinsic (demographic) noise. Extinction typically occurs via one of two scenarios depending on whether the absorbing state n=0 is a repelling (scenario A) or attracting (scenario B) point of the deterministic rate equation. In scenario A the metastable stochastic population resides in the vicinity of an attracting fixed point next to the repelling point n=0 . In scenario B there is an intermediate repelling point n=n1 between the attracting point n=0 and another attracting point n=n2 in the vicinity of which the metastable population resides. The crux of the theory is a dissipative variant of WKB (Wentzel-Kramers-Brillouin) approximation which assumes that the typical population size in the metastable state is large. Starting from the master equation, we calculate the quasistationary probability distribution of the population sizes and the (exponentially long) mean time to extinction for each of the two scenarios. When necessary, the WKB approximation is complemented (i) by a recursive solution of the quasistationary master equation at small n and (ii) by the van Kampen system-size expansion, valid near the fixed points of the deterministic rate equation. The theory yields both entropic barriers to extinction and pre-exponential factors, and holds for a general set of multistep processes when detailed balance is broken. The results simplify considerably for single-step processes and near the characteristic bifurcations of scenarios A and B. PMID:20365539

  20. Philippine president announces population policy.

    PubMed

    1970-02-01

    President Ferdinand Marcos of the Philippines has announced a national policy for family planning, following his recent reelection for a second term of office. Under the policy adopted by the President, the Philippine Government is committed to undertake and encourage programs to provide information and advice for couples wishing to space or limit their child-bearing activities. The Presidential Commission on Population, in a report based on recommendations drawn up after more than 20 meetings by the 22 members, and states that the unfettered population growth will gravely hamper efforts to improve living standards for Filipinos and will block the attainment of national development goals. However, the Commission emphasized that the program will be educational and persuasive, not coercive. Family planning services have been growing rapidly in the Philippines over the past few years as a result of the initiative of several pioneer organizations assisted by the IPPF. President Marcos' government signed the United Nations Declaration on Population in 1967 and in January 1969 he established The Commission on Population. The Philippine press has consistently backed the campaign for widespread availability of family planning services. The Western Pacific Region of the World Health Organization, under it's Director, Dr. Francisco Dy, which has its headquarters in Manila, has its headquarters in Manila, has fostered a regional interest through its technical discussions and the training of field personnel. Depthnews recently reported that the latest Philippine demographic survey asserts that Filipina women are bearing children so fast that the country will hold on to the undisputed title of possessing the highest birth rate in Asia. The growth rate is 3.5%, and the average completed size of a Filipino family is 6.8 children. This swift rate of growth will boost the 1969 population of 37.1 million to 38.4 at the end of this decade. It is noted that unless curbed, it will

  1. Population characteristics of Hawaii, 1982.

    PubMed

    Oyama, N; Nishi, S; Schmitt, R C

    1984-04-01

    This report, based on a 16,309 person sample of the 6 major islands, presents demographic, social, and economic charateristics for Hawaii in 1982. The Hawaii Health Surveillance Program survey, conducted by the Hawaii State Department of Health, collects health information principally and differs from the 1980 census since it does not include 37,600 persons living in Kalawao and Niihao. Hawaii's household population includes 956,100 persons, with 857,300 civilians, and 98,800 military or military related persons. The median age is 28.9 years; the ratio is 100.6 males to 100 females. More than 1/4 of the household population is of mixed race. The major ethnic groups include 25.5% Caucasian (although 24.7% of this group are military related), 22.3% Japanese, 18.3% Hawaiian, and 11.8% Filipino. 66.6% of the population was born in Hawaii, with 23.6% from other states or US territories, and 14.8% are of foreign birth (chiefly from the Philippines, Japan, Korea, and China). The average length of residence in Hawaii is 16.5 years. 86.6% of the population are native born and 7% are aliens. Mobility rates are high, largely due to the military presence. The population makes up 303,200 households, with an average household size of 3.15, and an average family size of 3.61. The median years of education for persons 25 and over is 12.7; most people work in technical occupations, sales, and administration, followed by managerial and professional speciality jobs. Service jobs and wholesale and retail trade dominate employment; the median income is $23,900 for families and $12,100 for unrelated individuals. PMID:12267641

  2. Innovatory aspects of population education.

    PubMed

    Casassus, J

    1985-06-01

    The expansion of population education activities in the last 10 years has led some authors to consider it as 1 of the most rapidly growing educational innovations in the world. This paper considers some of the most significant innovative aspects that can be drawn from the experience of different countries in the implementation of population education in the formal school system. Educational innovations present 2 phases: 1) the conception phase when the need is identified and the contents are determined and 2) the conduct of the innovation, which is the process through which the innovation is developed, evaluated, expanded, and becomes institutionalized. In the process of construction of population contents, 3 related approaches are used in order to render them meaningful: 1) interdisciplinarity, 2) the systemic approach, and 3) the interrelation between the macro and the micro level. It is commonly accepted that educational contents should meet the following 3 imperatives: relevance, coherence, and balance. The pedagogical act is conditioned by 3 interrelated elements: 1) by goals of education as they are expressed through the curriculum design and the contents developed, 2) by the role assumed by the teacher and the learner in the learning process, and 3) the pedagogical technics used by the teacher in order to attain the desired goals. In several countries, the role of population education has been enlarged to cover areas which had been traditionally confined to the private or family realm. Population education, by the nature of its contents and by the learning methodologies required, can become and has become in some countries, a major source for the renewal of education. PMID:12268121

  3. Pharmacogenetics in the Brazilian Population

    PubMed Central

    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 Refargen1, 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

  4. Population, Education, and Children's Futures. Fastback 150.

    ERIC Educational Resources Information Center

    Bjork, Robert M.; Fraser, Stewart E.

    This monograph discusses world population problems, examines the underlying concepts and issues in population education, and looks at the future. The monograph begins by describing an attempt at population education in a village of India. Eight guiding concepts that are considered to be essential for population educators are then discussed. These…

  5. Human Population: Fundamentals of Growth and Change.

    ERIC Educational Resources Information Center

    Stauffer, Cheryl Lynn, Ed.

    This booklet focuses on eight elements of population dynamics: "Population Growth and Distribution"; "Natural Increase and Future Growth"; "Effect of Migration on Population Growth"; "Three Patterns of Population Change"; "Patterns of World Urbanization"; "The Status of Women"; "World Health"; and "Environmental Relationships." Charts and graphs…

  6. Rising population and environmental degradation.

    PubMed

    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

  7. Environmental impact of population growth

    NASA Astrophysics Data System (ADS)

    Naylor, Rosamond; Matson, Pamela

    Earth's population currently numbers 5.4 billion; even given optimistic assumptions for reduction in growth rates, the number will double by the middle of the next century with most of the increase in the developing countries. Rapid population growth in the developing world raises the fundamental dilemma of how to alleviate chronic hunger and poverty in the short run while preserving the atmosphere and ecosystem services required for long-term human and biospheric sustenance. This dilemma, and the compromises required to solve it, were discussed by twenty-five researchers from five countries at the Aspen Global Change Institute 1992 Summer Science Session III, Food, Conservation, and Global Environmental Change: Is Compromise Possible?, held from August 16 to 28, in Aspen, Colo.

  8. [Population genetics of plant pathogens].

    PubMed

    Zhu, Wen; Zhan, Jia-Sui

    2012-02-01

    Comparing to natural ecosystems, the evolution of plant pathogens in agricultural ecosystems is generally faster due to high-density monocultures, large-scale application of agrochemicals, and international trade in agricultural products. Knowledge of the population genetics and evolutionary biology of plant pathogens is necessary to understand disease epidemiology, effectively breed and use resistant cultivars, and control plant diseases. In this article, we outlined the aims of population genetic studies in plant pathogens, discuss contributions of five evolutionary forces (i.e., mutation, gene flow, recombination, random genetic drift, and natural selection) to origin, maintenance, and distribution of genetic variation in time and space, and gave an overview of current research status in this field. PMID:22382057

  9. Dust Devil Populations and Statistics

    NASA Astrophysics Data System (ADS)

    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.

  10. Modeling Political Populations with Bacteria

    NASA Astrophysics Data System (ADS)

    Cleveland, Chris; Liao, David

    2011-03-01

    Results from lattice-based simulations of micro-environments with heterogeneous nutrient resources reveal that competition between wild-type and GASP rpoS819 strains of E. Coli offers mutual benefit, particularly in nutrient deprived regions. Our computational model spatially maps bacteria populations and energy sources onto a set of 3D lattices that collectively resemble the topology of North America. By implementing Wright-Fishcer re- production into a probabilistic leap-frog scheme, we observe populations of wild-type and GASP rpoS819 cells compete for resources and, yet, aid each other's long term survival. The connection to how spatial political ideologies map in a similar way is discussed.

  11. The Inner Oort Cloud Population

    NASA Astrophysics Data System (ADS)

    Sheppard, Scott; Trujillo, Chad

    2014-08-01

    The Kuiper Belt population has an outer edge at about 50 AU. Sedna and our recent discovery, 2012 VP113, are the only known objects with perihelion significantly beyond this edge at about 80 AU. These inner Oort cloud objects obtained their orbits when the solar system was vastly different from now. There are several theories as to the origin of these objects that can only be tested by finding several more. This population is likely larger than the Kuiper Belt but previous surveys did not go faint enough, did not have the required long cadence, or covered too small of sky area to find them. The dynamical and physical properties of objects in this region offer key constraints on the formation and evolution of our solar system. We propose to continue our survey with DECam in order to find several more inner Oort cloud objects to further constrain formation theories and thus learn about our Sun's formation environment and evolution.

  12. Access to bird population data

    USGS Publications Warehouse

    Martin, E.; Peterjohn, B.G.; Koneff, M.D.

    2001-01-01

    Access to bird population data is critical for effective conservation planning and implementation. Although a tremendous volume of baseline data exists, it is often diffusely distributed and inaccessible to the resource manager and decision maker. A mechanism that facilitates assembly, documentation and delivery of avian data in a user-friendly manner is needed in order to integrate bird-related information resources across agencies and organizations. To address this fundamental need, the National Biological Information Infrastructure (NBII), in partnership with the U.S. Geological Survey's Patuxent Wildlife Research Center and the U.S. Fish and Wildlife Service, is developing a web-based interactive system that will focus on access to bird population and habitat data used in bird management and conservation. This system, known as the NBII Bird Conservation Node, will support planning and evaluation of bird conservation activities within the context of the North American Bird Conservation Initiative (NABCI), a framework for collaboration among organizations interested in bird conservation across North America. Initial development of the NBII Bird Conservation Node will focus on creating a prototype mapping application that will provide interactive access to data from the North American Breeding Bird Survey, the Colonial Waterbird Survey, the Breeding Waterfowl Population and Habitat Survey, and the Atlantic Flyway Mid-winter Waterfowl Survey. This prototype mapping application, to be available on-line at http://www.nbii.gov by Sep 2001, will lay the foundation for establishment of a Migratory Bird Data Center at Patuxent Wildlife Research Center, and will provide an opportunity for linking to and establishing partnerships with other sources of bird population and habitat data available over the Internet.

  13. Bacterial computing with engineered populations.

    PubMed

    Amos, Martyn; Axmann, Ilka Maria; Blüthgen, Nils; de la Cruz, Fernando; Jaramillo, Alfonso; Rodriguez-Paton, Alfonso; Simmel, Friedrich

    2015-07-28

    We describe strategies for the construction of bacterial computing platforms by describing a number of results from the recently completed bacterial computing with engineered populations project. In general, the implementation of such systems requires a framework containing various components such as intracellular circuits, single cell input/output and cell-cell interfacing, as well as extensive analysis. In this overview paper, we describe our approach to each of these, and suggest possible areas for future research. PMID:26078340

  14. Population growth can be checked.

    PubMed

    Shukla, J P

    Since independence, India's population size has doubled. The rate of growth was 2.5% during 1971-81, an increase from the rate of 2.15% observed during the 1951-61 period. The increase indicated that efforts to decrease population growth have not succeeded. The implications with respect to food, housing, clothing, education, and health facilities, which are fundamental to improving the physical quality of life, are severe. This demographic trend is a serious impediment to progress. The population growth is due to a constant birthrate and a sharp decline in mortality. Reducing the birthrate is necessary to reduce the rate of growth. An attitudinal change adopting the norm of family limitation should be encouraged through propaganda, socioeconomic programs, and religious and cultural organizations. Other measures to bring about a decline in the birthrate include: increasing the marriage age, and expanding educational and employment opportunities for women and girls. These measures will require substantial effort and time. Incentives may show more immediate effects. Monetary incentives are not desired because of the possibility of misuse. However the government could assume responsibility for the education and guarantee employment of children of couples who have only one child, and provide free education to children of couples with only 2 children. These incentives are not likely to be misused, can be available to all segments of the population, and involve no immediate large financial burden on the government. In addition, scholarships to the Harijan students should be limited to 2 per family. If these measures are accepted, they could quickly reduce the birth rate. PMID:12311944

  15. The population question in Brazil.

    PubMed

    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

  16. The Diversity Outbred mouse population.

    PubMed

    Churchill, Gary A; Gatti, Daniel M; Munger, Steven C; Svenson, Karen L

    2012-10-01

    The Diversity Outbred (DO) population is a heterogeneous stock derived from the same eight founder strains as the Collaborative Cross (CC) inbred strains. Genetically heterogeneous DO mice display a broad range of phenotypes. Natural levels of heterozygosity provide genetic buffering and, as a result, DO mice are robust and breed well. Genetic mapping analysis in the DO presents new challenges and opportunities. Specialized algorithms are required to reconstruct haplotypes from high-density SNP array data. The eight founder haplotypes can be combined into 36 possible diplotypes, which must be accommodated in QTL mapping analysis. Population structure of the DO must be taken into account here. Estimated allele effects of eight founder haplotypes provide information that is not available in two-parent crosses and can dramatically reduce the number of candidate loci. Allele effects can also distinguish chance colocation of QTL from pleiotropy, which provides a basis for establishing causality in expression QTL studies. We recommended sample sizes of 200-800 mice for QTL mapping studies, larger than for traditional crosses. The CC inbred strains provide a resource for independent validation of DO mapping results. Genetic heterogeneity of the DO can provide a powerful advantage in our ability to generalize conclusions to other genetically diverse populations. Genetic diversity can also help to avoid the pitfall of identifying an idiosyncratic reaction that occurs only in a limited genetic context. Informatics tools and data resources associated with the CC, the DO, and their founder strains are developing rapidly. We anticipate a flood of new results to follow as our community begins to adopt and utilize these new genetic resource populations. PMID:22892839

  17. World Population Day special symposium.

    PubMed

    1998-08-01

    This article describes Japan's celebration of World Population Day, and provides excerpts from speeches at the symposium held on July 8, 1998. The symposium, in Tokyo, was attended by about 300 people. The Chairman of JOICFP gave the opening address. The executive director of UNFPA congratulated Japan for its efforts in the field of population awareness and noted Japan's self-sufficiency despite its importation of 40% of its food and most of its raw materials. A keynote address was delivered by the president of CPE and the former UN Secretary General, who stressed income inequities in the 66% of developing countries within the 185 UN member states. The UN has been promoting sustainable development, but is facing the issue of limited arable land and population growth. The Tutsi and Hutus are fighting due to population based issues. The emphasis should be on women's reproductive rights and protection of women's human rights. 1998 is the 50th year of human rights; progress has been made. The UNFPA Goodwill Ambassador spoke about the disparity between the rich and poor in the Philippines. A small donation reaps incredible progress. Manila has high levels of adolescent childbearing. Men appear to be unaware of the disadvantages of childbearing too early. Rural areas are dominated by strict Roman Catholic beliefs. Manila has commercial sex workers who provide services to Japanese men. The 1998 Kato Award was given to women who raised awareness about coercion in the sex trade and female genital mutilation. The economic situation in Japan creates even greater need to promote family planning and reproductive health. PMID:12321788

  18. Population mobility in Peninsular Malaysia.

    PubMed

    Jones, G W; Sidh, M S

    1979-12-01

    1970 census materials were used to analyze migration patterns in Peninsular Malaysia. Inter-state migration patterns were analyzed by comparing birth place and current place of residence data, and inter-district and intra-district migration patterns were assessed using information on previous and current place of residence. The proportion of inter-state migrants in the total population increased from 4.7%-10.9% from 1947-1970. 53% of the inter-state migrants were Malays, 33% were Chinese, and 13% were Indian. The states of Selangor and Pahang had the highest net migration gains and Perak had the highest number of out-migrants. Selangor attracted migrants because it was a major industrial, administrative and educational center. Migrants were attracted to Pahang because of recent efforts by the government to promote agricultural development in the state. Areas which showed a net migration loss were experiencing slow economic growth. 48.4% of the inter-state migrants migrated to either rural or suburban areas, 26% moved to cities with populations of 75,000 or more, and 26% moved to towns with populations of 1000-10,000. 48.6% of the inter-state migrants were females. When all types of internal migration were taken into account it was estimated that approximately 30% of the population had moved at some point in their life time. During the early 1900s, Peninsular Malaysia received many immigrants from China, India, and other countries, and the Chinese became the dominant group in many urban areas and in many economic sectors. In 1950 the government, fearing that the Malays would become a minority group in their own country, halted international immigration. The recent increase in internal migration has contributed toward equalizing the influence and power of the Chinese and the Malays in urban areas and in various economic sectors. PMID:12336532

  19. Big Microdata for Population Research

    PubMed Central

    Ruggles, Steven

    2013-01-01

    This article describes an explosion in the availability of individual-level population data. By 2018, demographic researchers will have access to over 2 billion records of accessible microdata from over 100 countries, dating from 1703 to the present. Another 2 to 4 billion records will be available through restricted-access data enclaves. These new resources represent a new kind of data that will enable transformative research on demographic and economic change and the spatial organization of society. PMID:24014182

  20. Association mapping in structured populations.

    PubMed

    Pritchard, J K; Stephens, M; Rosenberg, N A; Donnelly, P

    2000-07-01

    The use, in association studies, of the forthcoming dense genomewide collection of single-nucleotide polymorphisms (SNPs) has been heralded as a potential breakthrough in the study of the genetic basis of common complex disorders. A serious problem with association mapping is that population structure can lead to spurious associations between a candidate marker and a phenotype. One common solution has been to abandon case-control studies in favor of family-based tests of association, such as the transmission/disequilibrium test (TDT), but this comes at a considerable cost in the need to collect DNA from close relatives of affected individuals. In this article we describe a novel, statistically valid, method for case-control association studies in structured populations. Our method uses a set of unlinked genetic markers to infer details of population structure, and to estimate the ancestry of sampled individuals, before using this information to test for associations within subpopulations. It provides power comparable with the TDT in many settings and may substantially outperform it if there are conflicting associations in different subpopulations. PMID:10827107