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Sample records for lolium multiflorum populations

  1. 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...

  2. 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.

  3. 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

  4. QTL analysis of lodging resistance and related traits in Italian ryegrass ( Lolium multiflorum Lam.).

    PubMed

    Inoue, Maiko; Gao, Zhensheng; Cai, Hongwei

    2004-11-01

    Italian ryegrass ( Lolium multiflorum Lam.) is the most widely cultivated annual forage grass in Japan. Lodging damage reduces both harvested yield and forage quality. To identify the chromosomal regions controlling lodging resistance in Italian ryegrass, we analyzed seven quantitative characters--heading date, plant height, culm weight, culm diameter, culm strength, tiller number, and culm pushing resistance--and evaluated lodging scores in the field in a two-way pseudo-testcross F1 population. Significant correlations between most combinations of the traits examined were found. Seventeen QTLs for all traits except culm weight were detected on six of seven linkage groups by simple interval mapping using cross-pollination (CP) algorithm, and 33 independent QTLs were also detected by composite interval mapping from both male and female parental linkage maps. In addition, up to 18 QTLs for lodging scores evaluated at nine different times were detected on all linkage groups. The flanking markers of those QTLs will serve as a useful tool for marker-assisted selection of lodging resistance in Italian ryegrass.

  5. Utilization of flow cytometry to identify chimeral sectors in leaf tissue of Lolium multiflorum x L. arundinaceum hybrids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have identified a method whereby Lolium multiflorum (Lm) or L. arundinaceum (Fa) genomes are preferentially eliminated through a mitotic loss behavior in interspecific Lm x Fa F1 hybrids, generating either dihaploid Lm lines or Fa lines. Flow cytometry, a method for rapidly characterizing optical...

  6. 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...

  7. Consistent detection of QTLs for crown rust resistance in Italian ryegrass (Lolium multiflorum Lam.) across environments and phenotyping methods.

    PubMed

    Studer, Bruno; Boller, Beat; Bauer, Eva; Posselt, Ulrich K; Widmer, Franco; Kölliker, Roland

    2007-06-01

    Crown rust, caused by Puccinia coronata f. sp. lolii, is one of the most important diseases of temperate forage grasses, such as ryegrasses (Lolium spp.), affecting yield and nutritional quality. Therefore, resistance to crown rust is a major goal in ryegrass breeding programmes. In a two-way pseudo-testcross population consisting of 306 Lolium multiflorum individuals, multisite field evaluations as well as alternative methods based on artificial inoculation with natural inoculate in controlled environments were used to identify QTLs controlling resistance to crown rust. Disease scores obtained from glasshouse and leaf segment test (LST) evaluations were highly correlated with scores from a multisite field assessment (r = 0.66 and 0.79, P < 0.01, respectively) and thus confirmed suitability of these methods for crown rust investigations. Moreover, QTL mapping based on a linkage map consisting of 368 amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers revealed similar results across different phenotyping methods. Two major QTLs were consistently detected on linkage group (LG) 1 and LG 2, explaining up to 56% of total phenotypic variance (V (p)). Nevertheless, differences between position and magnitude of QTLs were observed among individual field locations and suggested the existence of specific local pathogen populations. The present study not only compared QTL results among crown rust evaluation methods and environments, but also identified molecular markers closely linked to previously undescribed QTLs for crown rust resistance in Italian ryegrass with the potential to be applied in marker-assisted forage crop breeding.

  8. Facilitation of a native pest of rice, Stenotus rubrovittatus (Hemiptera: Miridae), by the non-native Lolium multiflorum (Cyperales: Poaceae) in an agricultural landscape.

    PubMed

    Yoshioka, Akira; Takada, Mayura; Washitani, Izumi

    2011-10-01

    Source populations of polyphagous pests often occur on host plants other than the economically damaged crop. We evaluated the contribution of patches of a non-native meadow grass, Lolium multiflorum Lam. (Poaceae), and other weeds growing in fallow fields or meadows as source hosts of an important native pest of rice, Stenotus rubrovittatus (Matsumura) (Hemiptera: Miridae), in an agricultural landscape of northern Japan. Periodical censuses of this mirid bug by using the sweeping method, vegetation surveys, and statistical analysis revealed that L. multiflorum was the only plant species that was positively correlated with the density of adult S. rubrovittatus through two generations and thus may be the most stable and important host of the mirid bug early in the season before the colonization of rice paddies. The risk and cost of such an indirect negative effect on a crop plant through facilitation of a native pest by a non-native plant in the agricultural landscape should not be overlooked.

  9. 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.

  10. 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.

  11. Comparative “Golgi” Proteome Study of Lolium multiflorum and Populus trichocarpa

    PubMed Central

    Ford, Kristina L.; Chin, Tony; Srivastava, Vaibhav; Zeng, Wei; Doblin, Monika S.; Bulone, Vincent; Bacic, Antony

    2016-01-01

    The Golgi apparatus (GA) is a crucial organelle in the biosynthesis of non-cellulosic polysaccharides, glycoproteins and proteoglycans that are primarily destined for secretion to the cell surface (plasma membrane, cell wall and apoplast). Only a small proportion of the proteins involved in these processes have been identified in plants, with the majority of their functions still unknown. The availability of a GA proteome would greatly assist plant biochemists, cell and molecular biologists in determining the precise function of the cell wall-related proteins. There has been some progress towards defining the GA proteome in the model plant system Arabidopsis thaliana, yet in commercially important species, such as either the cereals or woody species there has been relatively less progress. In this study, we applied discontinuous sucrose gradient centrifugation to partially enrich GA from suspension cell cultures (SCCs) and combined this with stable isotope labelling (iTRAQ) to determine protein sub-cellular locations. Results from a representative grass species, Italian ryegrass (Lolium multiflorum) and a dicot species, black cottonwood (Populus trichocarpa) are compared. The results confirm that membrane fractionation approaches that provide effective GA-enriched fractions for proteomic analyses in Arabidopsis are much less effective in the species examined here and highlight the complexity of the GA, both within and between species. PMID:28248233

  12. 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.

  13. Integrated assessment of air pollution by metals and source apportionment using ryegrass (Lolium multiflorum Lam.) in southern Brazil.

    PubMed

    Illi, Júlia Carolina; Vancetta, Tafael; Alves, Darlan Daniel; Osório, Daniela Montanari Migliavacca; Bianchin, Liane; de Quevedo, Daniela Müller; Juchem, Fernando

    2017-01-01

    One of the biggest environmental problems existing today is air pollution, which is characterized by the presence of toxic gases and metal pollutants, the latter of which is generally associated with emissions of particulate matter (PM) from industries or automotive vehicles. Biomonitoring is a method that can be used to assess air pollution levels because it makes it possible to determine what effects these air pollutants cause in living organisms and their responses. The species Lolium multiflorum Lam., known as ryegrass, is considered a good bioindicator of metals, since it accumulates these substances during exposure. This study proposes to conduct an integrated assessment of air quality using two different monitoring methodologies: biomonitoring with L. multiflorum and active monitoring in areas with different levels of urbanization and industrialization. Concentrations found in ryegrass plants revealed high levels of Pb, Cr, Zn, and Cu, indicating that vehicular and industrial emissions were the main sources of pollution. Analysis of PM also revealed soot and biogenic particles, which can transport metals. Therefore, with the proposed method, the anthropogenic impact on air pollution in the investigated area could be clearly demonstrated.

  14. Short-term changes of fructans in ryegrass (Lolium multiflorum 'Lema') in response to urban air pollutants and meteorological conditions.

    PubMed

    Sandrin, Carla Zuliani; Figueiredo-Ribeiro, Rita de Cássia Leone; Delitti, Welington Braz Carvalho; Domingos, Marisa

    2013-10-01

    We investigated whether the fructan content, a storage carbohydrate, of Lolium multiflorum 'Lema' plants grown in a subtropical urban environment characterized by typical diurnal profiles of air pollutants and meteorological conditions changed over the course of a day during different seasons. Plants were collected every 2h on the last day of each two-month seasonal field experiment and separated into shoot (stubble or stubble+leaf blades) and roots for carbohydrate analyses and biomass determination. Diurnal contents of total fructose in the stubbles increased with high temperatures. In the roots, fructose accumulation showed a positive relation with hourly variations of both temperature and particulate matter and a negative relation with irradiance and SO2. Seasonal variation in shoot and root biomasses coincided with the seasonal variation of total fructose and were negatively affected by relative humidity and SO2, respectively. We concluded that hourly changes of fructans over the course of a day may increase the ability of L. multiflorum to tolerate short-term oscillations in weather and air pollution commonly observed in the subtropical urban environment, increasing its efficiency in monitoring air quality.

  15. 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

  16. Development of EST-derived CAPS and AFLP markers linked to a gene for resistance to ryegrass blast (Pyricularia sp.) in Italian ryegrass (Lolium multiflorum Lam.).

    PubMed

    Miura, Yuichi; Ding, Chenglong; Ozaki, Rie; Hirata, Mariko; Fujimori, Masahiro; Takahashi, Wataru; Cai, Hongwei; Mizuno, Kazuhiko

    2005-09-01

    Ryegrass blast, also called gray leaf spot, is caused by the fungus Pyricularia sp. It is one of the most serious diseases of Italian ryegrass (Lolium multiflorum Lam.) in Japan. We analyzed segregation of resistance in an F(1) population from a cross between a resistant and a susceptible cultivar. The disease severity distribution in the F(1) population suggested that resistance was controlled by a major gene (Lm Pi1). Analysis of amplified fragment length polymorphisms with bulked segregant analysis identified several markers tightly linked to Lm Pi1. To identify other markers linked to Lm Pi1, we used expressed sequence tag-cleaved amplified polymorphic sequence (EST-CAPS) markers mapped in a reference population of Italian ryegrass. Of the 30 EST-CAPS markers screened, one marker, p 56, flanking the Lm Pi1 locus was found. The restriction pattern of p 56 amplification showed a unique fragment corresponding to the resistant allele at the Lm Pi1 locus. A linkage map constructed from the reference population showed that the Lm Pi1 locus was located in linkage group 5 of Italian ryegrass. Genotype results obtained from resistant and susceptible cultivars indicate that the p 56 marker is useful for introduction of the Lm Pi1 gene into susceptible germ plasm in order to develop ryegrass cultivars with enhanced resistance to ryegrass blast.

  17. 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.

  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. 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.

  20. Treatment of an acid soil with bentonite used for wine fining: effects on soil properties and the growth of Lolium multiflorum.

    PubMed

    Arias-Estévez, Manuel; López-Periago, Eugenio; Nóvoa-Muñoz, Juan C; Torrado-Agrasar, Ana; Simal-Gándara, Jesus

    2007-09-05

    When used to fine wines, bentonite acquires a protein load that makes it a potentially useful fertilizer. Other properties of bentonite are also potentially useful for soil amendment. In the work described in this paper, waste bentonite from a winery was applied to an acid soil, and its effects on soil properties and on the growth of Lolium multiflorum were evaluated. Soil N, K, and P contents all increased, as did pH and cation exchange capacity. Biomass production increased as the dose of bentonite increased up to 5 g kg(-1), decreasing at larger doses (possibly as a result of falling potassium/magnesium ratio and increasing electrical conductivity). Environmental drawbacks of waste bentonite include its high soluble copper content, although its conversion in the soil to less soluble forms reduces its potential phytotoxicity. The copper, manganese, and zinc contents of the ryegrass crop were low.

  1. Phylogenetic and functional diversity of alkane degrading bacteria associated with Italian ryegrass (Lolium multiflorum) and Birdsfoot trefoil (Lotus corniculatus) in a petroleum oil-contaminated environment.

    PubMed

    Yousaf, Sohail; Andria, Verania; Reichenauer, Thomas G; Smalla, Kornelia; Sessitsch, Angela

    2010-12-15

    Twenty-six different plant species were analyzed regarding their performance in soil contaminated with petroleum oil. Two well-performing species, Italian ryegrass (Lolium multiflorum var. Taurus), Birdsfoot trefoil (Lotus corniculatus var. Leo) and the combination of these two plants were selected to study the ecology of plant-associated, culturable alkane-degrading bacteria. Hydrocarbon degrading bacteria were isolated from the rhizosphere, root interior and shoot interior and subjected to the analysis of 16S rRNA gene, the 16S and 23S rRNA intergenic spacer region and alkane hydroxylase genes. Furthermore, we investigated whether alkane hydroxylase genes are plasmid located. Higher numbers of culturable, alkane-degrading bacteria were associated with Italian ryegrass, which were also characterized by a higher diversity, particularly in the plant interior. Only half of the isolated bacteria hosted known alkane hydroxylase genes (alkB and cytochrome P153-like). Degradation genes were found both on plasmids as well as in the chromosome. In regard to application of plants for rhizodegradation, where support of numerous degrading bacteria is essential for efficient break-down of pollutants, Italian ryegrass seems to be more appropriate than Birdsfoot trefoil.

  2. In-vitro assessment of the probiotic potential of Lactobacillus plantarum KCC-24 isolated from Italian rye-grass (Lolium multiflorum) forage.

    PubMed

    Vijayakumar, Mayakrishnan; Ilavenil, Soundharrajan; Kim, Da Hye; Arasu, Mariadhas Valan; Priya, Kannappan; Choi, Ki Choon

    2015-04-01

    The aim of the present study was to determine the probiotic potential of the lactic acid bacteria Lactobacillus plantarum KCC-24 (L. plantarum KCC-24), that was isolated and characterized from Italian ryegrass (Lolium multiflorum) forage. The following experiments were performed to assess the probiotic characteristics such as antifungal activity, antibiotic susceptibility, resistance to low pH, stimulated gastric juice and bile salts, proteolytic activity, auto-aggregation, cell surface hydrophobicity, and in vitro antioxidant property. The isolated L. plantarum KCC-24 exhibited significant antifungal activity against the various fungal strains of Aspergillus fumigatus (73.43%), Penicillium chrysogenum (59.04%), Penicillium roqueforti (56.67%), Botrytis elliptica (40.23%), Fusarium oxysporum (52.47%) and it was susceptible to numerous antibiotics, survived in low pH, was resistant to stimulated gastric juices and bile salts (0.3% w/v). Moreover, L. plantarum KCC-24 exhibited good proteolytic activity. In addition L. plantarum KCC-24 showed potent antioxidant and hydrogen peroxide resistant property. In conclusion, the isolated L. plantarum KCC-24 exhibited several characteristics to prove it's excellent as a potential probiotic candidate for developing quality food for ruminant animals and human.

  3. 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

  4. 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.

  5. Phosphorus status and microbial community of paddy soil with the growth of annual ryegrass (Lolium multiflorum Lam.) under different phosphorus fertilizer treatments*

    PubMed Central

    Guo, Hai-chao; Wang, Guang-huo

    2009-01-01

    Annual ryegrass (Lolium multiflorum Lam.) was grown in paddy soil in pots under different phosphorus (P) fertilizer treatments to investigate changes of P fractions and microbial community of the soil. The treatments included Kunyang phosphate rock (KPR) applications at 50 mg P/kg (KPR50) and 250 mg P/kg (KPR250), mono-calcium phosphate (MCP) application at 50 mg P/kg (MCP50), and the control without P application. The results showed that KPR50, KPR250, and MCP50 applications significantly increased the dry weight of the ryegrass by 13%, 38%, and 55%, and increased P uptake by 19%, 135%, and 324%, respectively. Compared with MCP50, the relative effectiveness of KPR50 and KPR250 treatments in ryegrass production was about 23% and 68%, respectively. After one season of ryegrass growth, the KPR50, KPR250, and MCP50 applications increased soil-available P by 13.4%, 26.8%, and 55.2%, respectively. More than 80% of the applied KPR-P remained as HCl-P fraction in the soil. Phospholipid fatty acid (PLFA) analysis showed that the total and bacterial PLFAs were significantly higher in the soils with KPR250 and MCP50 treatments compared with KPR50 and control. The latter had no significant difference in the total or bacterial PLFAs. The KPR50, KPR250, and MCP50 treatments increased fungal PLFA by 69%, 103%, and 69%, respectively. Both the principal component analysis and the cluster analysis of the PLFA data suggest that P treatments altered the microbial community composition of the soils, and that P availability might be an important contributor to the changes in the microbial community structure during the ryegrass growth in the paddy soils. PMID:19817001

  6. 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...

  7. Influence of short-term drought conditions and subsequent re-watering on the physiology and proteome of Lolium multiflorum/Festuca arundinacea introgression forms, with contrasting levels of tolerance to long-term drought.

    PubMed

    Perlikowski, D; Kosmala, A; Rapacz, M; Kościelniak, J; Pawłowicz, I; Zwierzykowski, Z

    2014-03-01

    Festuca arundinacea is a drought tolerant species. Lolium multiflorum has better forage quality but lower tolerance to abiotic stresses. Their hybrids offer an opportunity to perform research on the molecular basis of tolerance to drought. The aim of this work was to recognise the mechanisms of response to short-term drought (11 days) in a glasshouse in two L. multiflorum/F. arundinacea introgression forms with distinct levels of tolerance to long-term drought (14 weeks) in the field. Measurements of physiological parameters, analyses of protein accumulation profiles using two-dimensional gel electrophoresis, and mass spectrometry identification of proteins, which were accumulated differentially between the selected genotypes during short-term drought, were performed. Genotype 7/6, with lower yield potential during 14 weeks of drought, and lower ability to re-grow after watering, had a higher capacity for photosynthesis during 11 days of drought. Genotype 4/10, more tolerant to long-term drought, was able to repair damaged cell membranes after watering and was also characterised by lower transpiration during short-term drought. A total of 455 proteins were analysed, and the 17 that were differentially accumulated between the two genotypes were identified. The results of physiological and proteomic research led to a hypothesis that the higher photosynthetic capacity of genotype 7/6 could be due to a more efficient Calvin cycle, supported by higher accumulation of crucial proteins involving chloroplast aldolase.

  8. 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

  9. Development of simple sequence repeat (SSR) markers and construction of an SSR-based linkage map in Italian ryegrass (Lolium multiflorum Lam.).

    PubMed

    Hirata, Mariko; Cai, Hongwei; Inoue, Maiko; Yuyama, Nana; Miura, Yuichi; Komatsu, Toshinori; Takamizo, Tadashi; Fujimori, Masahiro

    2006-07-01

    In order to develop simple sequence repeat (SSR) markers in Italian ryegrass, we constructed a genomic library enriched for (CA)n-containing SSR repeats. A total of 1,544 clones were sequenced, of which 1,044 (67.6%) contained SSR motifs, and 395 unique clones were chosen for primer design. Three hundred and fifty-seven of these clones amplified products of the expected size in both parents of a two-way pseudo-testcross F(1) mapping population, and 260 primer pairs detected genetic polymorphism in the F(1) population. Genetic loci detected by a total of 218 primer pairs were assigned to locations on seven linkage groups, representing the seven chromosomes of the haploid Italian ryegrass karyotype. The SSR markers covered 887.8 cM of the female map and 795.8 cM of the male map. The average distance between two flanking SSR markers was 3.2 cM. The SSR markers developed in this study will be useful in cultivar discrimination, linkage analysis, and marker-assisted selection of Italian ryegrass and closely related species.

  10. Untargeted Metabotyping Lolium perenne Reveals Population-Level Variation in Plant Flavonoids and Alkaloids

    PubMed Central

    Cao, Mingshu; Fraser, Karl; Jones, Chris; Stewart, Alan; Lyons, Thomas; Faville, Marty; Barrett, Brent

    2017-01-01

    Metabolomics provides a powerful platform to characterize plants at the biochemical level, allowing a search for underlying genes and associations with higher level complex traits such as yield and nutritional value. Efficient and reliable methods to characterize metabolic variation in economically important species are considered of high value to the evaluation and prioritization of germplasm and breeding lines. In this investigation, a large-scale metabolomic survey was performed on a collection of diverse perennial ryegrass (Lolium perenne L.) plants. A total of 2,708 data files, derived from liquid chromatography coupled to high resolution mass spectrometry (LCMS), were selected to assess the effectiveness and efficiency of applying high throughput metabolomics to survey chemical diversity in plant populations. The data set was generated from 23 ryegrass populations, with 3–25 genotypes per population, and five clonal replicates per genotype. We demonstrate an integrated approach to rapidly mine and analyze metabolic variation from this large, multi-batch LCMS data set. After performing quality control, statistical data mining and peak annotation, a wide range of variation for flavonoid glycosides and plant alkaloids was discovered among the populations. Structural variation of flavonoids occurs both in aglycone structures and acetylated/malonylated/feruloylated sugar moieties. The discovery of comprehensive metabolic variation among the plant populations offers opportunities to probe into the genetic basis of the variation, and provides a valuable resource to gain insight into biochemical functions and to relate metabolic variation with higher level traits in the species. PMID:28223996

  11. Evolution of glyphosate resistance in a Lolium rigidum population by glyphosate selection at sublethal doses.

    PubMed

    Busi, R; Powles, S B

    2009-10-01

    The majority of the documented cases of field-evolved herbicide-resistant weed biotypes established that single major genes confer glyphosate resistance. However, the contribution of minor genes endowing substantial plant survival at sublethal herbicide doses may be a potential complementary path to herbicide resistance evolution in weed populations under selection. Here, we subjected a number of susceptible individuals of Lolium rigidum to recurrent glyphosate selection to test the potential for sublethal glyphosate doses to additively select for glyphosate resistance. After 3-4 cycles of glyphosate selection in two distinct environments, the progenies of the initially susceptible population were shifted toward glyphosate resistance. The results indicate progressive enrichment of minor gene trait(s) contributing toward plant survival in the glyphosate-selected progenies. After three generations of selection, the estimated LD(50) values were doubled compared with the original population and up to 33% plant survival was obtained in the glyphosate-selected progeny at the recommended glyphosate label rate. This level of resistance probably was the maximum shift achievable with sublethal glyphosate dose selection in this small population. Cross-pollination was a crucial factor enabling the rapid rate of accumulation of minor glyphosate resistance gene trait(s) that are likely to be present at a relatively high frequency in a small susceptible population. The mechanistic basis of the moderate glyphosate resistance level selected by sublethal glyphosate doses remains unknown and warrants future research. Studying the main factors influencing the evolution of resistant weed populations is crucial for understanding, predicting and managing herbicide resistance.

  12. 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 ...

  13. 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...

  14. Four QTLs determine crown rust (Puccinia coronata f. sp. lolii) resistance in a perennial ryegrass (Lolium perenne) population.

    PubMed

    Muylle, H; Baert, J; Van Bockstaele, E; Pertijs, J; Roldán-Ruiz, I

    2005-11-01

    Crown rust resistance is an important selection criterion in ryegrass breeding. The disease, caused by the biotrophic fungus Puccinia coronata, causes yield losses and reduced quality. In this study, we used linkage mapping and QTL analysis to unravel the genomic organization of crown rust resistance in a Lolium perenne population. The progeny of a pair cross between a susceptible and a resistant plant were analysed for crown rust resistance. A linkage map, consisting of 227 loci (AFLP, SSR, RFLP and STS) and spanning 744 cM, was generated using the two-way pseudo-testcross approach from 252 individuals. QTL analysis revealed four genomic regions involved in crown rust resistance. Two QTLs were located on LG1 (LpPc4 and LpPc2) and two on LG2 (LpPc3 and LpPc1). They explain 12.5, 24.9, 5.5 and 2.6% of phenotypic variance, respectively. An STS marker, showing homology to R genes, maps in the proximity of LpPc2. Further research is, however, necessary to check the presence of functional R genes in this region. Synteny at the QTL level between homologous groups of chromosomes within the Gramineae was observed. LG1 and LG2 show homology with group A and B chromosomes of oat on which crown rust-resistance genes have been identified, and with the group 1 chromosomes of the Triticeae, on which leaf rust-resistance genes have been mapped. These results are of major importance for understanding the molecular background of crown rust resistance in ryegrasses. The identified markers linked to crown rust resistance have the potential for use in marker-assisted breeding.

  15. Plastome Sequence Determination and Comparative Analysis for Members of the Lolium-Festuca Grass Species Complex

    PubMed Central

    Hand, Melanie L.; Spangenberg, German C.; Forster, John W.; Cogan, Noel O. I.

    2013-01-01

    Chloroplast genome sequences are of broad significance in plant biology, due to frequent use in molecular phylogenetics, comparative genomics, population genetics, and genetic modification studies. The present study used a second-generation sequencing approach to determine and assemble the plastid genomes (plastomes) of four representatives from the agriculturally important Lolium-Festuca species complex of pasture grasses (Lolium multiflorum, Festuca pratensis, Festuca altissima, and Festuca ovina). Total cellular DNA was extracted from either roots or leaves, was sequenced, and the output was filtered for plastome-related reads. A comparison between sources revealed fewer plastome-related reads from root-derived template but an increase in incidental bacterium-derived sequences. Plastome assembly and annotation indicated high levels of sequence identity and a conserved organization and gene content between species. However, frequent deletions within the F. ovina plastome appeared to contribute to a smaller plastid genome size. Comparative analysis with complete plastome sequences from other members of the Poaceae confirmed conservation of most grass-specific features. Detailed analysis of the rbcL–psaI intergenic region, however, revealed a “hot-spot” of variation characterized by independent deletion events. The evolutionary implications of this observation are discussed. The complete plastome sequences are anticipated to provide the basis for potential organelle-specific genetic modification of pasture grasses. PMID:23550121

  16. Biodegradation of phenanthrene, spatial distribution of bacterial populations and dioxygenase expression in the mycorrhizosphere of Lolium perenne inoculated with Glomus mosseae.

    PubMed

    Corgié, S C; Fons, F; Beguiristain, T; Leyval, C

    2006-05-01

    Interactions between the plant and its microbial communities in the rhizosphere control microbial polycyclic aromatic hydrocarbons (PAH) biodegradation processes. Arbuscular mycorrhizal (AM) fungi can influence plant survival and PAH degradation in polluted soil. This work was aimed at studying the contribution of the mycorrhizosphere to PAH biodegradation in the presence of ryegrass (Lolium perenne L., cv. Barclay) inoculated with Glomus mosseae (BEG 69) by taking into account the structure and activity of bacterial communities, PAH degrading culturable bacteria as a function of the distance from roots. Ryegrass was grown in compartmentalized systems designed to harvest successive sections of rhizosphere in lateral compartments polluted or not with phenanthrene (PHE). Colonization of roots by G. mosseae (BEG 69) modified the structure and density of bacterial populations in the mycorrhizosphere, compared to the rhizosphere of non-mycorrhizal plants. G. mosseae increased the density of culturable heterotrophic and PAH degrading bacteria beyond the immediate rhizosphere in the presence of PHE, and increased the density of PAH degraders in the absence of the pollutant. Biodegradation was not significantly increased in the mycorrhizosphere, compared to control non-mycorrhizal plants, where PHE biodegradation already reached 92% after 6 weeks. However, dioxygenase transcriptional activity was found to be higher in the immediate mycorrhizosphere in the presence of G. mosseae (BEG 69).

  17. Identification of genomic loci associated with crown rust resistance in perennial ryegrass (Lolium perenne L.) divergently selected populations.

    PubMed

    Brazauskas, Gintaras; Xing, Yongzhong; Studer, Bruno; Schejbel, Britt; Frei, Ursula; Berg, Paul Ragnar; Lübberstedt, Thomas

    2013-07-01

    The inheritance of crown rust resistance in perennial ryegrass is complex with both major and minor quantitative trait loci (QTL) being detected on all seven linkage groups. However, QTL mapping populations have only few segregating alleles, limiting the transferability of results to other materials. In this study, a synthetic population was developed from four crown rust resistant and susceptible parents as starting material for a divergent selection experiment of crown rust resistance to be closer to practice in plant breeding programs, and to identify genome regions relevant across a broader range of genotypes. Following three cycles of directional selection, perennial ryegrass populations were produced with a two-fold difference in average rust resistance. Divergently selected populations were genotyped at 7 resistance gene analog-derived expressed sequence tag (RGA-derived EST) as well as 15 simple sequence repeat (SSR) loci. A test for selective neutrality (Waples test), which tests the hypothesis of genetic drift versus selection, identified significant differences in allele frequencies for 7 loci (32%). The selection effect was bidirectional with the same loci showing significant response in both positively and negatively selected populations. A region under selection represented by markers LpSSR006 and EST13 on linkage group (LG) 4 was further confirmed by colocation with two separate QTL for crown rust resistance in a VrnA, a two-way pseudo-testcross mapping population. This suggests suitability of alleles identified for introgression into perennial ryegrass germplasm, where quantitative resistance to crown rust is desired.

  18. Contrasting genetic structure between Magnaporthe grisea populations associated with the golf course turfgrasses Lolium perenne (perennial ryegrass) and Pennisetum clandestinum (kikuyugrass).

    PubMed

    Douhan, Greg W; de la Cerda, Karla A; Huryn, Karyn L; Greer, Christopher A; Wong, Francis P

    2011-01-01

    Gray leaf spot (GLS) disease of perennial ryegrass (Lolium perenne) and kikuyugrass (Pennisetum clandestinum) in golf courses in California was first noted in 2001 and 2003, respectively, and within 5 years had become well established. The causal agent of the disease is the fungus Magnaporthe grisea, which is known to consist primarily of clonal lineages that are highly host specific. Therefore, our objective was to investigate host specificity and population dynamics among isolates associated primarily from perennial ryegrass and kikuyugrass since the disease emerged at similar times in California. We also obtained isolates from additional hosts (tall fescue, St. Augustinegrass, weeping lovegrass, and rice) and from the eastern United States for comparative purposes. A total of 38 polymorphic amplified fragment length polymorphism makers were scored from 450 isolates which clustered by host with high bootstrap support (71 to 100%). Genetic structure between kikuyugrass and perennial ryegrass isolates differed significantly. Isolates from kikuyugrass were genotypically diverse (n = 34), possessed both mating types, and some tests for random mating could not be rejected, whereas isolates from perennial ryegrass were less genotypically diverse (n = 10) and only consisted of a single mating type. Low genotypic diversity was also found among the other host specific isolates which also only consisted of a single mating type. This is the first study to document evidence for the potential of sexual reproduction to occur in M. grisea isolates not associated with rice (Oryza sativa). Moreover, given the significant host specificity and contrasting genetic structures between turfgrass-associated isolates, the recent emergence of GLS on various grass hosts in California suggests that potential cultural practices or environmental changes have become conducive for the disease and that the primary inoculum may have already been present in the state, despite the fact that two

  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. Leaf Rubisco turnover in a perennial ryegrass (Lolium perenne L.) mapping population: genetic variation, identification of associated QTL, and correlation with plant morphology and yield.

    PubMed

    Khaembah, Edith N; Irving, Louis J; Thom, Errol R; Faville, Marty J; Easton, H Sydney; Matthew, Cory

    2013-03-01

    This study tested the hypotheses that: (i) genetic variation in Rubisco turnover may exist in perennial ryegrass (Lolium perenne L.); (ii) such variation might affect nitrogen use efficiency and plant yield; and (iii) genetic control of Rubisco turnover might be amenable to identification by quantitative trait loci (QTL) mapping. A set of 135 full-sib F1 perennial ryegrass plants derived from a pair cross between genotypes from the cultivars 'Grasslands Impact' and 'Grasslands Samson' was studied to test these hypotheses. Leaf Rubisco concentration at different leaf ages was measured and modelled as a log-normal curve described by three mathematical parameters: D (peak Rubisco concentration), G (time of D), and F (curve standard deviation). Herbage dry matter (DM) yield and morphological traits (tiller weight (TW), tiller number (TN), leaf lamina length (LL), and an index of competitive ability (PI)) were also measured. The progeny exhibited continuous variation for all traits. Simple correlation and principal component analyses indicated that plant productivity was associated with peak Rubisco concentration and not Rubisco turnover. Lower DM was associated with higher leaf Rubisco concentration indicating that Rubisco turnover effects on plant productivity may relate to energy cost of Rubisco synthesis rather than photosynthetic capacity. QTL detection by a multiple QTL model identified seven significant QTL for Rubisco turnover and nine QTL for DM and morphological traits. An indication of the genetic interdependence of DM and the measures of Rubisco turnover was the support interval overlap involving QTL for D and QTL for TN on linkage group 5 in a cluster involving QTL for DM and PI. In this region, alleles associated with increased TN, DM, and PI were associated with decreased D, indicating that this region may regulate Rubisco concentration and plant productivity via increased tillering. A second cluster involving QTL for LL, TN, PI and DM was found on

  1. 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.

  2. 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 ...

  3. Phenanthrene and Pyrene Modify the Composition and Structure of the Cultivable Endophytic Bacterial Community in Ryegrass (Lolium multiflorum Lam)

    PubMed Central

    Zhu, Xuezhu; Jin, Li; Sun, Kai; Li, Shuang; Li, Xuelin; Ling, Wanting

    2016-01-01

    This study provides new insights into the dynamics of bacterial community structure during phytoremediation. The communities of cultivable autochthonous endophytic bacteria in ryegrass exposed to polycyclic aromatic hydrocarbons (PAHs) were investigated with regard to their potential to biodegrade PAHs. Bacterial counts and 16S rRNA gene sequence were used in the microbiological evaluation. A total of 33 endophytic bacterial strains were isolated from ryegrass plants, which represented 15 different genera and eight different classes, respectively. Moreover, PAH contamination modified the composition and structure of the endophytic bacterial community in the plants. Bacillus sp., Pantoea sp., Pseudomonas sp., Arthrobacter sp., Pedobacter sp. and Delftia sp. were only isolated from the seedlings exposed to PAHs. Furthermore, the dominant genera in roots shifted from Enterobacter sp. to Serratia sp., Bacillus sp., Pantoea sp., and Stenotrophomonas sp., which could highly biodegrade phenanthrene (PHE). However, the diversity of endophytic bacterial community was decreased by exposure to the mixture of PAHs, and increased by respective exposure to PHE and pyrene (PYR), while the abundance was increased by PAH exposure. The results clearly indicated that the exposure of plants to PAHs would be beneficial for improving the effectiveness of phytoremediation of PAHs. PMID:27827894

  4. 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.

  5. 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...

  6. 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...

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

    PubMed

    Carris, Lori M; Castlebury, Lisa A; Huang, Guoming; Alderman, Steve C; Luo, Jiafeng; Bao, Xiaodong

    2007-12-01

    A bunt fungus, exhibiting a spore germination pattern unique to known reticulate-spored species of Tilletia was found infecting plants in seed production fields of Festuca rubra ssp. rubra (red fescue) and F. rubra ssp. fallax (Chewing's fescue) in Oregon, and in seed lots of Lolium perenne (perennial ryegrass) from Australia and Germany. Teliospores germinated to form 20-40 uninucleate, non-conjugating basidiospores, and colonies derived from single basidiospores produced teliospores in culture. In inoculation studies using single basidiospore colonies, perennial ryegrass and L. perenne ssp. multiflorum (Italian or annual ryegrass) were infected. A phylogenetic analysis, based on ITS region rDNA, eukaryotic translation elongation factor 1 alpha, and the second largest subunit of RNA polymerase II demonstrated that the fescue and ryegrass bunts are conspecific, and distinct from known species of Tilletia.

  8. 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

  9. Landscape effects of a non-native grass facilitate source populations of a native generalist bug, Stenotus rubrovittatus, in a heterogeneous agricultural landscape.

    PubMed

    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.

  10. 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

  11. 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.

  12. 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

  13. Aploneura lentisci (Homoptera: Aphididae) and Its Interactions with Fungal Endophytes in Perennial Ryegrass (Lolium perenne)

    PubMed Central

    Popay, Alison J.; Cox, Neil R.

    2016-01-01

    Aploneura lentisci Pass. is endemic to the Mediterranean region where it is holocyclic, forming galls on its primary host, Pistacia lentiscus and alternating over a 2-year period between Pistacia and secondary hosts, principally species of Gramineae. This aphid is widely distributed in Australia and New Zealand on the roots of the common forage grasses, ryegrass (Lolium spp.) and tall fescue (Schedonorus phoenix) where it exists as permanent, anholocyclic, parthenogenetic populations. Previous studies have indicated that infestations of A. lentisci significantly reduce plant growth and may account for differences in field performance of Lolium perenne infected with different strains of the fungal endophyte Epichloë festucae var. lolii. These obligate biotrophs protect their host grasses from herbivory via the production of alkaloids. To confirm the hypothesis that growth of L. perenne is associated with the effect of different endophyte strains on aphid populations, herbage and root growth were measured over time in two pot trials that compared three fungal endophyte strains with an endophyte-free control. In both pot trials, aphid numbers were lowest on plants infected with endophyte strain AR37 at all sampling times. In plants infected with a common toxic strain naturalized in New Zealand, aphid numbers overall were lower than on uninfected plants or those infected with strain AR1, but numbers did not always differ significantly from these treatments. Populations on AR1-infected plants were occasionally significantly higher than those on endophyte-free. Cumulative foliar growth was reduced in AR1 and Nil treatments relative to AR37 in association with population differences of A. lentisci in both trials and root dry weight was reduced in one trial. In four Petri dish experiments survival of A. lentisci on plants infected with AR37 declined to low levels after an initial phase of up to 19 days during which time aphids fed and populations were similar to those on

  14. De novo Sequencing and Comparative Transcriptomics of Floral Development of the Distylous Species Lithospermum multiflorum

    PubMed Central

    Cohen, James I.

    2016-01-01

    Genes controlling the morphological, micromorphological, and physiological components of the breeding system distyly have been hypothesized, but many of the genes have not been investigated throughout development of the two floral morphs. To this end, the present study is an examination of comparative transcriptomes from three stages of development for the floral organs of the morphs of Lithospermum multiflorum. Transcriptomes of flowers of the two morphs, from various stages of development, were sequenced using an Illumina HiSeq 2000. The floral transcriptome of L. multiflorum was assembled, and differential gene expression (DE) was identified between morphs, throughout development. Additionally, Gene Ontology (GO) terms for DE genes were determined. Fewer genes were DE early in development compared to later in development, with more genes highly expressed in the gynoecium of the SS morph and the corolla and androecium of the LS morph. A reciprocal pattern was observed later in development, and many more genes were DE during this latter stage. During early development, DE genes appear to be involved in growth and floral development, and during later development, DE genes seem to affect physiological functions. Interestingly, many genes involved in response to stress were identified as DE between morphs. PMID:28066486

  15. 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

  16. 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

  17. Production of anthraquinones, phenolic compounds and biological activities from hairy root cultures of Polygonum multiflorum Thunb.

    PubMed

    Thiruvengadam, Muthu; Praveen, Nagella; Kim, Eun-Hye; Kim, Seung-Hyun; Chung, Ill-Min

    2014-05-01

    Polygonum multiflorum Thunb. is a highly important medicinal plant producing anthraquinones (emodin and physcion) and phenolic compounds which has pharmaceutical use. In vitro seedling explants such as roots, internodals, nodals and leaves were inoculated with A. rhizogenes strain KCTC 2703. Transformed roots were induced from internodals and leaf explants. Six transgenic clones of hairy roots were established and confirmed by polymerase chain reaction (PCR) and reverse transcription-PCR (RT-PCR) using rolC specific primers. Hairy roots cultured using MS liquid medium supplemented with 30 g/l sucrose showed highest accumulation of biomass (99.05 g/l FW [fresh weight] and 10.95 g/l DW [dry weight]) and highest production of anthraquinones content (emodin 211.32 μg/g DW and physcion 353.23 μg/g DW) were observed at 20 days. Nearly 9.5-fold increment of biomass was evident in suspension cultures at 20 days of culture and hairy root biomass produced in suspension cultures possessed 3.7- and 3.5-fold higher content of emodin and physcion, respectively, when compared with the untransformed control roots. MS basal liquid medium was superior for the growth of hairy roots and production of anthraquinones compared with other culture media evaluated (SH, B5 and N6), with MS-basal liquid medium supplemented with 30 g/l sucrose was optimal for secondary metabolite production. A total of 23 polyphenolic compounds were identified and quantified from P. multiflorum untransformed and hairy roots, which includes hydroxybenzoic acids, hydroxycinnamic acids, flavonols and other groups of phenolic compounds. The ultra-performance liquid chromatography (UPLC) analysis of the phenolic compounds profile revealed that pyrogallol, hesperidin, naringenin and formononetin were higher in hairy roots compared to untransformed roots. The total phenolics, flavonoids content, antioxidant and antimicrobial activity was high in hairy roots compared to untransformed roots. This is the first

  18. 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

  19. Interchangeable effects of gibberellic acid and temperature on embryo growth, seed germination and epicotyl emergence in Ribes multiflorum ssp. sandalioticum (Grossulariaceae).

    PubMed

    Mattana, E; Pritchard, H W; Porceddu, M; Stuppy, W H; Bacchetta, G

    2012-01-01

    Morphophysiological dormancy was investigated in seeds of Ribes multiflorum Kit ex Roem et Schult. ssp. sandalioticum Arrigoni, a rare mountain species endemic to Sardinia (Italy). There were no differences in imbibition rates between intact and scarified seeds, suggesting a lack of physical dormancy, while methylene blue solution (0.5%) highlighted a preferential pathway for solution entrance through the raphe. Embryos were small at seed dispersal, with an initial embryo:seed ratio (E:S) of ca. 0.2 (embryo length, ca. 0.5 mm), whereas the critical E:S ratio for germination was three times longer (ca. 0.6). Gibberellic acid (GA(3), 250 mg · l(-1)) and warm stratification (25 °C for 3 months) followed by low temperature (<15 °C) enhanced embryo growth rate (maximum of ca. 0.04 mm · day(-1) at 10 °C) and subsequent seed germination (radicle emergence; ca. 80% at 10 °C). Low germination occurred at warmer temperatures, and cold stratification (5 °C for 3 months) induced secondary dormancy. After radicle emergence, epicotyl emergence was delayed for ca. 2 months for seeds from three different populations. Mean time of epicotyl emergence was affected by GA(3) . Seeds of this species showed non-deep simple (root) - non-deep simple (epicotyl) morphophysiological dormancy, highlighting a high synchronisation with Mediterranean seasonality in all the investigated populations.

  20. A New Strategy for Quality Evaluation and Identification of Representative Chemical Components in Polygonum multiflorum Thunb.

    PubMed Central

    Gong, Xiao-hong; Liu, Mei-chen

    2017-01-01

    Polygonum multiflorum Thunb. (HSW) is widely used as herb medicine and health food additive. Recently, a series of HSW-induced hepatotoxicities have been reported and many studies have been carried out to investigate it. But contradictory conclusions were drawn that might be caused by the inconsistent quality of market decoction pieces. Therefore, the HSW decoction pieces quality was evaluated with a developed novel method in the paper. 25 batches of raw HSW (RHSW) and 21 batches of processed HSW (PHSW) samples were purchased from different provinces of China. HPLC determination was performed to identify and detect the contents of 16 chemical compounds in herbal material. Fingerprint similarity was analyzed using chromatography information and the results showed that most herbs were in good similarity. Then, a comprehensive evaluation strategy based on principal component analysis with representative quality control indicators was developed to evaluate the quality of HSW samples. And the rationality of the developed method was verified by HCA analysis. The results showed that the herb from Dabashan, Sichuan Province, no matter RHSW or PHSW had the best quality. Different representative components were selected for RHSW or PHSW decoction pieces which might be caused by the chemical reaction during processing. And most PHSW were unqualified according to the requirement of Chinese Pharmacopeia which might take the responsibility for the toxicity of HSW. PMID:28243311

  1. Polygonum multiflorum root extract as a potential candidate for treatment of early graying hair

    PubMed Central

    Thang, Nguyen Dinh; Diep, Pham Ngoc; Lien, Pham Thi Huong; Lien, Le Thi

    2017-01-01

    Despite Polygonum multiflorum (PM) has been experiencely used as a drug to treat early graying hair phenomenon in Asian countries for a long time, there is limited study examined the real biological effects of PM on hair graying in vitro and in vivo. In this study, we investigated the effects of PM root extract (PM-RE) on melanin synthesis in human melanoma SKMEL-28 cells and embryos/larvae of wild-type strain AB zebrafish. We also preliminary revealed the molecular mechanism of early hair graying phenomenon in both in vitro and in vivo models. Our results showed that PM-RE significantly induced melanin synthesis in melanin-producing SKMEL-28 melanoma cells and also in zebrafish embryos/larvae at 4-day postfertilization through activation of MC1R/MITF/tyrosinase-signaling pathway. We also investigated the differences in genotype between graying hair follicle and black hair follicle of young peoples and found that early hair graying phenomenon may be related to downregulation of MC1R/MITF/tyrosinase pathway. Taken together, we suggested that PM-RE at safe doses could be used as a potential agent for the treatment of early hair graying and other loss pigmentation-related diseases. PMID:28217548

  2. Acute hepatitis due to shen-min: a herbal product derived from Polygonum multiflorum.

    PubMed

    Cárdenas, Andrés; Restrepo, Juan Carlos; Sierra, Fernando; Correa, Gonzalo

    2006-08-01

    Shen-Min is a herbal product sold as a supplement for women to enhance hair growth. It is widely available across Asia, Europe, and the United States and sold without prescription as a hair nutritional supplement. We describe a case of acute liver injury in a 28-year-old white woman who developed symptomatic hepatitis 8 weeks after starting Shen-Min. All other potential causes of acute hepatitis including viral, hypoxic/ischemic, metabolic, and autoimmune etiologies were excluded. The liver injury slowly resolved over 3 weeks after discontinuing the herbal product. Although the mechanism of Shen-Min hepatotoxicity is unknown, we suspect an idiosyncratic reaction because the patient developed a fine maculopapular rash, mild eosinophilia, and did not overdose. Shen-Min is a Chinese herbal product with a mixture of several plants and vitamins including Polygonum multiflorum, a root that has been previously associated with hepatotoxicity. Nonetheless to our knowledge this is the first reported case of herbal-induced hepatotoxicity in a patient taking Shen-Min per se. Clinicians taking care of patients with acute hepatitis of unclear etiology should be aware that the consumption of Shen-Min, a hair supplement widely available in the United States and Western countries might cause acute hepatitis.

  3. Effects of Hot Water Extracts from Polygonum multiflorum on Ovariectomy Induced Osteopenia in Mice

    PubMed Central

    Hwang, Yun-Ho; Kang, Kyung-Yun; Kim, Jong-Jin; Lee, Sung-Ju; Son, Young-Jin

    2016-01-01

    Polygonum multiflorum (PM), a traditional Chinese medicine, is used to treat various diseases including nonalcoholic fatty liver disease and hyperlipidemia. However, the influence of PM on osteoporosis in animals is unclear. The present study investigated the antiosteoporotic effect of PM on bone mass in ovariectomized (OVX) mice and its possible mechanism of action. Twenty-five female C3H/HeN mice were divided into five groups of five mice as follows. Sham-operated control mice received daily oral gavage of an equal volume of water, and OVX mice received daily oral gavage of water or an injection of β-estradiol or PM for 6 weeks. Administration of PM significantly suppressed body weight and organs weight and increased weight and length of bone compared with the OVX group. Treatment with PM reversed osteopenia in OVX mice, thereby improving the bone morphometric parameters. Moreover, histological analysis using hematoxylin and eosin staining showed that PM inhibited OVX-induced bone loss. Serum estradiol and bone alkaline phosphatase levels were significantly decreased in the OVX group, with the levels increasing with PM treatment. In addition, tartrate-resistant acid phosphatase activity was inhibited by PM in OVX mice. These results suggest that PM is effective in preventing bone loss in OVX mice. PMID:27746822

  4. 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.

  5. 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...

  6. Profiling of phenolic constituents in Polygonum multiflorum Thunb. by combination of ultra-high-pressure liquid chromatography with linear ion trap-Orbitrap mass spectrometry.

    PubMed

    Qiu, Xiaohui; Zhang, Jing; Huang, Zhihai; Zhu, Dayuan; Xu, Wen

    2013-05-31

    A simple and effective method was developed for characterization of phenolic constituents in the roots of Polygonum multiflorum by combination of ultra-high-pressure liquid chromatography with linear ion trap-Orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap). Stilbenes, anthraquinones, tannins and naphthalenes were differentiated by diagnostic fragment ions with accurate mass measurements and characteristic fragmentation pathways. Based on the proposed strategy, fifty-nine constituents were characterized or tentatively identified, of which twenty-two constituents were the first to be reported in P. multiflorum and twelve compounds were characterized as potential new compounds. The identification and structure elucidation of these chemicals provided essential data for further phytochemical studies and quality control of P. multiflorum. The results also demonstrated that our novel method can be extended to screen and characterize other phenolic constituents and their metabolites in botanical extracts.

  7. Enhanced Production of Anthraquinones and Phenolic Compounds and Biological Activities in the Cell Suspension Cultures of Polygonum multiflorum.

    PubMed

    Thiruvengadam, Muthu; Rekha, Kaliyaperumal; Rajakumar, Govindasamy; Lee, Taek-Jun; Kim, Seung-Hyun; Chung, Ill-Min

    2016-11-16

    Anthraquinones (AQs) and phenolic compounds are important phytochemicals that are biosynthesized in cell suspension cultures of Polygonum multiflorum. We wanted to optimize the effects of plant growth regulators (PGRs), media, sucrose, l-glutamine, jasmonic acid (JA), and salicylic acid (SA) for the production of phytochemicals and biomass accumulation in a cell suspension culture of P. multiflorum. The medium containing Murashige and Skoog (MS) salts and 4% sucrose supplemented with 1 mg/L 2,4-dichlorophenoxyacetic acid, 0.5 mg/L thidiazuron, and 100 µM l-glutamine at 28 days of cell suspension culture was suitable for biomass accumulation and AQ production. Maximum biomass accumulation (12.5 and 12.35 g fresh mass (FM); 3 and 2.93 g dry mass (DM)) and AQ production (emodin 295.20 and 282 mg/g DM; physcion 421.55 and 410.25 mg/g DM) were observed using 100 µM JA and SA, respectively. JA- and SA-elicited cell cultures showed several-fold higher biomass accumulation and AQ production than the control cell cultures. Furthermore, the cell suspension cultures effectively produced 23 phenolic compounds, such as flavonols and hydroxycinnamic and hydroxybenzoic acid derivatives. PGR-, JA-, and SA-elicited cell cultures produced a higher amount of AQs and phenolic compounds. Because of these metabolic changes, the antioxidant, antimicrobial, and anticancer activities were high in the PGR-, JA-, and SA-elicited cell cultures. The results showed that the elicitors (JA and SA) induced the enhancement of biomass accumulation and phytochemical (AQs and phenolic compounds) production as well as biological activities in the cell suspension cultures of P. multiflorum. This optimized protocol can be developed for large-scale biomass accumulation and production of phytochemicals (AQs and phenolic compounds) from cell suspension cultures, and the phytochemicals can be used for various biological activities.

  8. Enhanced Production of Anthraquinones and Phenolic Compounds and Biological Activities in the Cell Suspension Cultures of Polygonum multiflorum

    PubMed Central

    Thiruvengadam, Muthu; Rekha, Kaliyaperumal; Rajakumar, Govindasamy; Lee, Taek-Jun; Kim, Seung-Hyun; Chung, Ill-Min

    2016-01-01

    Anthraquinones (AQs) and phenolic compounds are important phytochemicals that are biosynthesized in cell suspension cultures of Polygonum multiflorum. We wanted to optimize the effects of plant growth regulators (PGRs), media, sucrose, l-glutamine, jasmonic acid (JA), and salicylic acid (SA) for the production of phytochemicals and biomass accumulation in a cell suspension culture of P. multiflorum. The medium containing Murashige and Skoog (MS) salts and 4% sucrose supplemented with 1 mg/L 2,4-dichlorophenoxyacetic acid, 0.5 mg/L thidiazuron, and 100 µM l-glutamine at 28 days of cell suspension culture was suitable for biomass accumulation and AQ production. Maximum biomass accumulation (12.5 and 12.35 g fresh mass (FM); 3 and 2.93 g dry mass (DM)) and AQ production (emodin 295.20 and 282 mg/g DM; physcion 421.55 and 410.25 mg/g DM) were observed using 100 µM JA and SA, respectively. JA- and SA-elicited cell cultures showed several-fold higher biomass accumulation and AQ production than the control cell cultures. Furthermore, the cell suspension cultures effectively produced 23 phenolic compounds, such as flavonols and hydroxycinnamic and hydroxybenzoic acid derivatives. PGR-, JA-, and SA-elicited cell cultures produced a higher amount of AQs and phenolic compounds. Because of these metabolic changes, the antioxidant, antimicrobial, and anticancer activities were high in the PGR-, JA-, and SA-elicited cell cultures. The results showed that the elicitors (JA and SA) induced the enhancement of biomass accumulation and phytochemical (AQs and phenolic compounds) production as well as biological activities in the cell suspension cultures of P. multiflorum. This optimized protocol can be developed for large-scale biomass accumulation and production of phytochemicals (AQs and phenolic compounds) from cell suspension cultures, and the phytochemicals can be used for various biological activities. PMID:27854330

  9. Structural, physicochemical, antioxidant and antitumor property of an acidic polysaccharide from Polygonum multiflorum.

    PubMed

    Zhu, Weili; Xue, Xiaoping; Zhang, Zhanjun

    2017-03-01

    In this study, the structural characterization, physicochemical property, antioxidant and antitumor activity of an acidic polysaccharide (APS) from Polygonum multiflorum were investigated. Monosaccharide composition analysis showed APS was composed of arabinose, rhamnose, galactose and galacturonic acid in the molar ratio of 1.23:1.32:1.48:1.00. The presence of uronic acid was also confirmed by the bands at 1740, 1645 and 1425cm(-1) on Fourier transform-infrared spectroscopy. Methylation and nuclear magnetic resonance analyses showed APS was mainly composed by the residues of →5)-α-l-Araf-(1→, →3)-β-d-Galp-(1→, →3,6)-β-d-Galp-(1→, →4)-α-d-GalAp-(1→ and →2)-α-l-Rhap-(1→ in the backbone. The non-reducing terminal α-l-Araf-(1→ was probably attached to the O-6 position of →3,6)-β-d-Galp-(1→ residues. Besides, APS exhibited rod-like and flaky shapes with rough surface. The initial decomposition of APS occurred at 172°C, and the rapidest weight loss rate of APS appeared at 320°C. Antioxidant activity assay showed the DPPH radical scavenging activity of APS was 67.5% at 1mg/mL. At the concentration of 400μg/mL, the antiproliferation activities of APS against HepG-2 and BGC-823 cells were 65.28% and 51.57%, respectively. Our results suggested APS could be a potential antioxidant and antitumor agent.

  10. Effects of Jasminum multiflorum leaf extract on rodent models of epilepsy, motor coordination and anxiety.

    PubMed

    Addae, Jonas I; Pingal, Ramish; Walkins, Kheston; Cruickshank, Renee; Youssef, Farid F; Nayak, Shivananda B

    2017-03-01

    Jasmine flowers and leaves are used extensively in folk medicine in different parts of the world to treat a variety of diseases. However, there are very few published reports on the neuropsychiatric effects of Jasmine extracts. Hence, the objectives of the present study were to examine the effects of an alcohol extract of Jasminum multiflorum leaves on topically-applied bicuculline (a model of acute simple partial epilepsy) and maximal electroshock (MES, a model of generalized tonic-clonic seizure) in male Sprague-Dawley rats. The objectives also included an examination of the anxiolytic properties of the extract using an elevated plus maze and the effect of the extract on motor coordination using a rotarod treadmill. Phytochemical analysis of the extract showed the presence of three flavonoids and four additional compounds belonging to the steroid, terpenoid, phenol or sugar classes of compounds. The Jasmine alcohol extract, diluted with water and given orally or intraperitoneally, reduced the number of bicuculline-induced epileptiform discharges in a dose-dependent manner. The extract did not cause a significant increase in the current needed to induce hind limb extension in MES experiments. The extract significantly affected motor coordination when injected at 500mg/kg but not at 200mg/kg. At the latter dose, the extract increased open-arm entries and duration in the elevated plus maze to a level comparable to that of diazepam at 2mg/kg. We conclude that Jasmine leaf extract has a beneficial effect against an animal model of acute partial complex epilepsy, and significant anxiolytic effect at a dose that does not affect motor co-ordination.

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. Host genotype overrides fungal endophyte infection in influencing tiller and spike production of Lolium perenne (Poaceae) in a common garden experiment.

    PubMed

    Cheplick, Gregory P

    2008-09-01

    Leaves of many cool-season grasses are infected by endophytic fungi that can impact their populations. A common garden experiment with Lolium perenne was established in a lawn in New Jersey, USA, to investigate the impact of endophyte infection and host genotype on tiller and spike production over three years. Infected (E+) and uninfected (E-) plants of each genotype were monitored every 2-3 mo. Infection intensity within plants varied significantly among genotypes and years, but there was no evidence of directional change over time. Tiller production varied significantly among genotypes and was affected by endophytes: E+ plants of several genotypes produced more tillers than E- plants during the third year. E+ plants had greater aboveground biomass, but host genotype explained a far greater proportion of variation in tiller production, number, and biomass than infection. Plant survival, percentage flowering, flowering date, number of spikes, and mean tiller mass were unaffected by endophytes. However, the last three variables showed significant variation among host genotypes. Although studies have demonstrated a positive growth effect of endophytes on several grass hosts, in this experiment host genotype accounted for far more of the variation in tiller and spike production and in biomass of Lolium perenne than endophyte infection.

  17. Silage from maize (Zea mays), annual ryegrass (Lolium multiflorum) or their mixture in the dry season feeding of grazing dairy cows in small-scale dairy production systems in the highlands of Mexico.

    PubMed

    Anaya-Ortega, J P; Garduño-Castro, G; Espinoza-Ortega, A; Rojo-Rubio, R; Arriaga-Jordán, C M

    2009-04-01

    Small-scale dairy systems based on grazing have dry-season herbage shortages. A repeated 3 x 3 Latin Square experiment evaluated grazing with silage from maize (MS), annual ryegrass (ARG) or a mixture (MIX) with 9 cows with 3 week periods; continuously grazed at 3.6 cows/ha with 3.6 kg DM/day of concentrate. Treatments were 7 kg DM of MS, ARG or a 2 MS:1 ARG mixture. Milk yield (MY), milk composition, live-weight, body condition, silage and concentrate intake were recorded. Herbage DM intake was estimated indirectly. Activity budgets were done for economic analysis. MY on MS (21.5 kg/cow/d) was 0.06 higher than on ARG (P < 0.09) with no differences on MIX. There were no differences for milk fat, milk protein, or body condition score. Live-weight on ARG was higher (P < 0.01) than on MS or MIX. Silage intake was higher (P < 0.01) on ARG and MS than on MIX. Herbage intake was lower (P < 0.05) on MS, compared with MIX and ARG. Total DM intake on ARG was higher than MS (P < 0.01), and MIX in between. MS resulted in 0.12 higher economic returns over ARG which had highest costs. Annual ryegrass may have a place in small-scale systems, but not as silage due to higher costs.

  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. A potential role for endogenous microflora in dormancy release, cytokinin metabolism and the response to fluridone in Lolium rigidum seeds

    PubMed Central

    Goggin, Danica E.; Emery, R. J. Neil; Kurepin, Leonid V.; Powles, Stephen B.

    2015-01-01

    Background and Aims Dormancy in Lolium rigidum (annual ryegrass) seeds can be alleviated by warm stratification in the dark or by application of fluridone, an inhibitor of plant abscisic acid (ABA) biosynthesis via phytoene desaturase. However, germination and absolute ABA concentration are not particularly strongly correlated. The aim of this study was to determine if cytokinins of both plant and bacterial origin are involved in mediating dormancy status and in the response to fluridone. Methods Seeds with normal or greatly decreased (by dry heat pre-treatment) bacterial populations were stratified in the light or dark and in the presence or absence of fluridone in order to modify their dormancy status. Germination was assessed and seed cytokinin concentration and composition were measured in embryo-containing or embryo-free seed portions. Key Results Seeds lacking bacteria were no longer able to lose dormancy in the dark unless supplied with exogenous gibberellin or fluridone. Although these seeds showed a dramatic switch from active cytokinin free bases to O-glucosylated storage forms, the concentrations of individual cytokinin species were only weakly correlated to dormancy status. However, cytokinins of apparently bacterial origin were affected by fluridone and light treatment of the seeds. Conclusions It is probable that resident microflora contribute to dormancy status in L. rigidum seeds via a complex interaction between hormones of both plant and bacterial origin. This interaction needs to be taken into account in studies on endogenous seed hormones or the response of seeds to plant growth regulators. PMID:25471097

  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.

  1. 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…

  2. [Population].

    PubMed

    1979-01-01

    Data on the population of Venezuela between 1975 and 1977 are presented in descriptive tables and graphs. Information is included on the employed population according to category, sex, and type of economic activity, and by sex, age, and area on the employment rate and the total, the economically active, and the unemployed population.

  3. Comparison of Early Development of Three Grasses: Lolium perenne, Agrostis stolonifera and Poa pratensis

    PubMed Central

    FUSTEC, JOELLE; GUILLEUX, JOELLE; LE CORFF, JOSIANE; MAITRE, JEAN-PAUL

    2005-01-01

    • Background and Aims To improve the management of grass communities, early plant development was compared in three species with contrasting growth forms, a caespitose (Lolium perenne), a rhizomatous (Poa pratensis) and a caespitose–stoloniferous species (Agrostis stolonifera). • Methods Isolated seedlings were grown in a glasshouse without trophic constraints for 37 d (761 °Cd). The appearance of leaves and their location on tillers were recorded. Leaf appearance rate (LAR) on the tillers and site-filling were calculated. Tillering was modelled based on the assumption that tiller number increases with the number of leaves produced on the seedling main stem. Above- and below-ground parts were harvested to compare biomass. • Key Results Lolium perenne and A. stolonifera expressed similar bunch-type developments. However, root biomass was approx. 30 % lower in A. stolonifera than in L. perenne. Poa pratensis was rhizomatous. Nevertheless, the ratio of above-ground : below-ground biomass of P. pratensis was similar to that of L. perenne. LAR was approximately equal to 0·30 leaf d−1 in L. perenne, and on the main stem and first primary tillers of A. stolonifera. LAR on the other tillers of A. stolonifera was 30 % higher than on L. perenne. For P. pratensis, LAR was 30 % lower than on L. perenne, but the interval between the appearance of two successive shoots from rhizomes was 30 % higher than the interval between two successive leaf stages on the main stem. Above-ground parts of P. pratensis first grew slower than in the other species to the benefit of the rhizomes, whose development enhanced tiller production. • Conclusions Lolium perenne had the fastest tiller production at the earliest stages of seedling development. Agrostis stolonifera and P. pratensis compensated almost completely for the delay due to higher LAR on tillers or ramets compared with L. perenne. This study provides a basis for modelling plant development. PMID:15932884

  4. Endophytic fungus decreases plant virus infections in meadow ryegrass (Lolium pratense)

    PubMed Central

    Lehtonen, Päivi T; Helander, Marjo; Siddiqui, Shahid A; Lehto, Kirsi; Saikkonen, Kari

    2006-01-01

    We studied the effects of fungal endophyte infection of meadow ryegrass (Lolium pratense=Festuca pratensis) on the frequency of the barley yellow dwarf virus (BYDV). The virus is transferred by aphids, which may be deterred by endophyte-origin alkaloids within the plant. In our experiment, we released viruliferous aphid vectors on endophyte-infected and endophyte-free plants in a common garden. The number of aphids and the percentage of BYDV infections were lower in endophyte-infected plants compared to endophyte-free plants, indicating that endophyte infection may protect meadow ryegrass from BYDV infections. PMID:17148304

  5. Population.

    ERIC Educational Resources Information Center

    International Planned Parenthood Federation, London (England).

    In an effort to help meet the growing interest and concern about the problems created by the rapid growth of population, The International Planned Parenthood Federation has prepared this booklet with the aim of assisting the study of the history and future trends of population growth and its impact on individual and family welfare, national,…

  6. Stilbene glucoside from Polygonum multiflorum Thunb.: a novel natural inhibitor of advanced glycation end product formation by trapping of methylglyoxal.

    PubMed

    Lv, Lishuang; Shao, Xi; Wang, Liyan; Huang, Derong; Ho, Chi-Tang; Sang, Shengmin

    2010-02-24

    Methylglyoxal (MGO), the reactive dicarbonyl intermediate generated during the nonenzymatic glycation between reducing sugars and amino groups of proteins, lipids, and DNA, is the precursor of advanced glycation end products (AGEs). Many studies have shown that AGEs play a major pathogenic role in diabetes and its complications. This study found that 2,3,5,4'-tetrahydroxystilbene 2-O-beta-D-glucoside (THSG), the major bioactive compound from Polygonum multiflorum Thunb., can efficiently inhibit the formation of AGEs in a dose-dependent manner by trapping reactive MGO under physiological conditions (pH 7.4, 37 degrees C). More than 60% MGO was trapped by THSG within 24 h, which was much more effective than resveratrol and its methylated derivative, pterostilbene, the two major bioactive dietary stilbenes. The major mono- and di-MGO adducts of THSG were successfully purified and found to be mixtures of tautomers. LC-MS and NMR data showed that positions 4 and 6 of the A ring were the major active sites for trapping MGO. It was also found that THSG could significantly inhibit the formation of AGEs in the human serum albumin (HSA)-MGO assay and both mono- and di-MGO adducts of THSG were detected in this assay using LC-MS. The results suggest that the ability of THSG to trap reactive dicarbonyl species makes it a potential natural inhibitor of AGEs.

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

    PubMed

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

    2014-11-01

    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.

  8. 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

  9. Variation in Alkaloid Production from Genetically Diverse Lolium Accessions Infected with Epichloë Species.

    PubMed

    Moore, Joseph R; Pratley, James E; Mace, Wade J; Weston, Leslie A

    2015-12-09

    Widespread infection of Epichloë occultans in annual ryegrass in Australia suggests that infection provides its weedy host, Lolium rigidum, some ecological advantage. Initial studies determined the distribution and profiles of known Epichloë alkaloids (epoxy-janthitrems, ergovaline, lolines, lolitrem B, and peramine) in plant extracts using a combination of GC-FID and HPLC techniques utilizing a single accession of Australian L. rigidum. However, the lolines N-acetylnorloline (NANL) and N-formylloline (NFL) were the only alkaloids detected and were highly concentrated in the immature inflorescences of mature plants. Additional glasshouse studies subjected a wide range of Australian L. rigidum haplotypes and international annual Lolium accessions to a suite of analyses to determine alkaloid levels and profiles. Again, NFL and NANL were the key lolines produced, with NFL consistently predominating. Considerable variation in alkaloid production was found both within and between biotypes and accessions evaluated under identical conditions, at the same maturation stage and on the same tissue type. The pyrrolopyrazine alkaloid peramine was also present in 8 out of 17 Australian biotypes of L. rigidum and 7 out of 33 international accessions infected with Epichloë spp.; the highest peramine concentrations were observed in seed extracts from L. rigidum collected from Australia. This study represents the first report of alkaloids from a geographically diverse collection of annual ryegrass germplasm infected with Epichloë spp. when grown under identical controlled conditions.

  10. 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

    2015-12-26

    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.

  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.

  12. [Control of the fermentation activity during ensilage of Lolium italicum A. Br. and Medicago sativa L].

    PubMed

    Ozino Marletto, O I; Ambrosoli, R; Piccone, G; Biasiol, B

    1982-01-01

    Samples with different dry matter contents of Lolium italicum A. Br., Medicago sativa L., have been ensiled in hermetically sealed containers, in order to study the evolution of microflora and its activity. The principal microbial groups (coliforms, proteolytics , lactic acid bacteria, clostridia, yeasts) have been detected and enumerated, in anaerobic atmosphere, after ensiling periods of 3, 6, 10, 13, 20, 100 days. At the same time, the samples were chemically analyzed for the detection of: pH, moisture, ashes, total and ammoniacal nitrogen, total reducing sugars, lactic acid, volatile fatty acids, short chain alcohols. The relations found between chemical and microbiological data, show that a strong lactic fermentation is not enough for the inhibition of silage spoiling microorganisms, such as coliforms, yeasts, and (less) proteolytics . This phenomenon may be related to the "quality" of the lactic acid microflora, more than to the characteristics of the environment.

  13. Micropropagation of Polygonum multiflorum THUNB and quantitative analysis of the anthraquinones emodin and physcion formed in in vitro propagated shoots and plants.

    PubMed

    Lin, Li-Chang; Nalawade, Satish Manohar; Mulabagal, Vanisree; Yeh, Mau-Shing; Tsay, Hsin-Sheng

    2003-10-01

    An efficient and rapid protocol for in vitro induction and complete plant regeneration of Polygonum multiflorum THUNB has been developed. Nodal explants were grown in vitro on Murashige and Skoog's (MS) basal medium containing different concentrations of alpha-naphthaleneacetic acid (NAA) and benzyladenine (BA). The nodal explants (97%) produced multiple shoots (4.7 shoots per explant) on MS basal medium supplemented with 0.2 mg/l NAA and 2.0 mg/l BA after 6 weeks of culture. Eighty-eight percent to 100% of the shoots (1.0 cm in length) elongated (about 3.02-4.28 cm) and rooted on MS basal medium supplemented with NAA or indole-3-butyric acid (IBA). All the rooted shoots were transferred to pots containing autoclaved soil, vermiculite, and peat moss (1 : 1 : 1). The plantlets were successfully acclimatized under greenhouse conditions with high humidity before transferring to the field. The anthraquinone contents were determined using HPLC. Analysis revealed that the contents of the major medicinal compounds-emodin and physcion in the 6 weeks old in vitro grown shoots and three month old in vitro propagated plants grown in greenhouse were higher than those of the marketed crude drug (processed underground or stem parts of P. multiflorum).

  14. Insights into the molecular mechanisms of Polygonum multiflorum Thunb-induced liver injury: a computational systems toxicology approach.

    PubMed

    Wang, Yin-Yin; Li, Jie; Wu, Zeng-Rui; Zhang, Bo; Yang, Hong-Bin; Wang, Qin; Cai, Ying-Chun; Liu, Gui-Xia; Li, Wei-Hua; Tang, Yun

    2017-02-27

    An increasing number of cases of herb-induced liver injury (HILI) have been reported, presenting new clinical challenges. In this study, taking Polygonum multiflorum Thunb (PmT) as an example, we proposed a computational systems toxicology approach to explore the molecular mechanisms of HILI. First, the chemical components of PmT were extracted from 3 main TCM databases as well as the literature related to natural products. Then, the known targets were collected through data integration, and the potential compound-target interactions (CTIs) were predicted using our substructure-drug-target network-based inference (SDTNBI) method. After screening for hepatotoxicity-related genes by assessing the symptoms of HILI, a compound-target interaction network was constructed. A scoring function, namely, Ascore, was developed to estimate the toxicity of chemicals in the liver. We conducted network analysis to determine the possible mechanisms of the biphasic effects using the analysis tools, including BiNGO, pathway enrichment, organ distribution analysis and predictions of interactions with CYP450 enzymes. Among the chemical components of PmT, 54 components with good intestinal absorption were used for analysis, and 2939 CTIs were obtained. After analyzing the mRNA expression data in the BioGPS database, 1599 CTIs and 125 targets related to liver diseases were identified. In the top 15 compounds, seven with Ascore values >3000 (emodin, quercetin, apigenin, resveratrol, gallic acid, kaempferol and luteolin) were obviously associated with hepatotoxicity. The results from the pathway enrichment analysis suggest that multiple interactions between apoptosis and metabolism may underlie PmT-induced liver injury. Many of the pathways have been verified in specific compounds, such as glutathione metabolism, cytochrome P450 metabolism, and the p53 pathway, among others. Hepatitis symptoms, the perturbation of nine bile acids and yellow or tawny urine also had corresponding pathways

  15. 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

  16. 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

  17. 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.

  18. ABA inhibits germination but not dormancy release in mature imbibed seeds of Lolium rigidum Gaud.

    PubMed Central

    Goggin, Danica E.; Steadman, Kathryn J.; Emery, R. J. Neil; Farrow, Scott C.; Benech-Arnold, Roberto L.; Powles, Stephen B.

    2009-01-01

    Dormancy release in imbibed annual ryegrass (Lolium rigidum Gaud.) seeds is promoted in the dark but inhibited in the light. The role of abscisic acid (ABA) in inhibition of dormancy release was found to be negligible, compared with its subsequent effect on germination of dormant and non-dormant seeds. Inhibitors of ABA metabolism had the expected effects on seed germination but did not influence ABA concentration, suggesting that they act upon other (unknown) factors regulating dormancy. Although gibberellin (GA) synthesis was required for germination, the influence of exogenous GA on both germination and dormancy release was minor or non-existent. Embryo ABA concentration was the same following treatments to promote (dark stratification) and inhibit (light stratification) dormancy release; exogenous ABA had no effect on this process. However, the sensitivity of dark-stratified seeds to ABA supplied during germination was lower than that of light-stratified seeds. Therefore, although ABA definitely plays a role in the germination of annual ryegrass seeds, it is not the major factor mediating inhibition of dormancy release in imbibed seeds. PMID:19487389

  19. 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.

  20. Expression and characterization of an antifreeze protein from the perennial rye grass, Lolium perenne.

    PubMed

    Lauersen, Kyle J; Brown, Alan; Middleton, Adam; Davies, Peter L; Walker, Virginia K

    2011-06-01

    Antifreeze proteins (AFP) are an evolutionarily diverse class of stress response products best known in certain metazoans that adopt a freeze-avoidance survival strategy. The perennial ryegrass, Lolium perenne (Lp), cannot avoid winter temperatures below the crystallization point and is thought to use its LpAFP in a freeze-tolerant strategy. In order to examine properties of LpAFP in relation to L. perenne's life history, cDNA cloning, recombinant protein characterization, ice-binding activities, gene copy number, and expression responses to low temperature were examined. Transcripts, encoded by only a few gene copies, appeared to increase in abundance after diploid plants were transferred to 4°C for 1-2 days, and in parallel with the ice recrystallization inhibition activities. Circular dichroism spectra of recombinant LpAFP showed three clear folding transition temperatures including one between 10 and 15°C, suggesting to us that folding modifications of the secreted AFP could allow the targeted degradation of the protein in planta when temperatures increase. Although LpAFP showed low thermal hysteresis activity and partitioning into ice, it was similar to AFPs from freeze-avoiding organisms in other respects. Therefore, the type of low temperature resistance strategy adopted by a particular species may not depend on the type of AFP. The independence of AFP sequence and life-history has practical implications for the development of genetically-modified crops with enhanced freeze tolerance.

  1. 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.

  2. Metabolite profiling during cold acclimation of Lolium perenne genotypes distinct in the level of frost tolerance.

    PubMed

    Bocian, Aleksandra; Zwierzykowski, Zbigniew; Rapacz, Marcin; Koczyk, Grzegorz; Ciesiołka, Danuta; Kosmala, Arkadiusz

    2015-11-01

    Abiotic stresses, including low temperature, can significantly reduce plant yielding. The knowledge on the molecular basis of stress tolerance could help to improve its level in species of relatively high importance to agriculture. Unfortunately, the complex research performed so far mainly on model species and also, to some extent, on cereals does not fully cover the demands of other agricultural plants of temperate climate, including forage grasses. Two Lolium perenne (perennial ryegrass) genotypes with contrasting levels of frost tolerance, the high frost tolerant (HFT) and the low frost tolerant (LFT) genotypes, were selected for comparative metabolomic research. The work focused on the analysis of leaf metabolite accumulation before and after seven separate time points of cold acclimation. Gas chromatography-mass spectrometry (GC/MS) was used to identify amino acids (alanine, proline, glycine, glutamic and aspartic acid, serine, lysine and asparagine), carbohydrates (fructose, glucose, sucrose, raffinose and trehalose) and their derivatives (mannitol, sorbitol and inositol) accumulated in leaves in low temperature. The observed differences in the level of frost tolerance between the analysed genotypes could be partially due to the time point of cold acclimation at which the accumulation level of crucial metabolite started to increase. In the HFT genotype, earlier accumulation was observed for proline and asparagine. The increased amounts of alanine, glutamic and aspartic acids, and asparagine during cold acclimation could be involved in the regulation of photosynthesis intensity in L. perenne. Among the analysed carbohydrates, only raffinose revealed a significant association with the acclimation process in this species.

  3. Complete amino acid sequence of a Lolium perenne (perennial rye grass) pollen allergen, Lol p II.

    PubMed

    Ansari, A A; Shenbagamurthi, P; Marsh, D G

    1989-07-05

    The complete amino acid sequence of a Lolium perenne (rye grass) pollen allergen, Lol p II was determined by automated Edman degradation of the protein and selected fragments. Cleavage of the protein by enzymatic and chemical techniques established an unambiguous sequence for the protein. Lol p II contains 97 amino acid residues, with a calculated molecular weight of 10,882. The protein lacks cysteine and glutamine and shows no evidence of glycosylation. Theoretical predictions by Fraga's (Fraga, S. (1982) Can. J. Chem. 60, 2606-2610) and Hopp and Woods' (Hopp, T. P., and Woods, K. R. (1981) Proc. Natl. Acad. Sci. U.S.A. 78, 3824-3828) methods indicate the presence of four hydrophilic regions, which may contribute to sequential or parts of conformational B-cell epitopes. Analysis of amphipathic regions by Berzofsky's method indicates the presence of a highly amphipathic region, which may contain, or contribute to, an Ia/T-cell epitope. This latter segment of Lol p II was found to be highly homologous with an antibody-binding segment of the major rye allergen Lol p I and may explain why immune responsiveness to both the allergens is associated with HLA-DR3.

  4. Monoclonal antibodies to the major Lolium perenne (rye grass) pollen allergen Lol p I (Rye I).

    PubMed

    Kahn, C R; Marsh, D G

    1986-12-01

    Thirteen monoclonal antibodies (MAbs) were produced against Lol p I (Rye I), the major Lolium perenne (rye grass) pollen allergen. Spleen cells from A/J and SJL mice immunized with highly purified Lol p I (Lol I) were allowed to fuse with cells from the non-secreting Sp2/0-Ag14 myeloma cell line. Each MAb was analyzed for antigenic specificity by radioimmunoassay (RIA) using 125I-Lol I. The epitope specificities of seven of the MAbs were examined by competitive binding against a labelled standard MAb for the Lol I antigen (Ag). The dissociation constant, Kd, of one MAb (No. 3.2) that was studied most extensively was determined by double Ab RIA to be 3.5 X 10(-6) L/M. This MAb recognized the related 27,000-30,000 Group I glycoproteins found in the pollens of nine other species of grass pollens tested, including weak binding to Bermuda grass Group I (Cyn d I), which by conventional analysis using polyclonal anti-Lol I serum shows no detectable binding. Monoclonal antibody No. 3.2 was coupled covalently to Sepharose 4B and used to prepare highly purified Lol I from a partially purified rye pollen extract. Finally, an RIA was developed which permitted the analysis of the Group I components in rye grass and nine other grass pollen species. The latter assay is likely to prove useful in the standardization of grass pollen extracts according to their Group I contents.

  5. Early response mechanisms of perennial ryegrass (Lolium perenne) to phosphorus deficiency

    PubMed Central

    Byrne, Stephen L.; Foito, Alexandre; Hedley, Pete E.; Morris, Jenny A.; Stewart, Derek; Barth, Susanne

    2011-01-01

    Background and Aims Improving phosphorus (P) nutrient efficiency in Lolium perenne (perennial ryegrass) is likely to result in considerable economic and ecological benefits. To date, research into the molecular and biochemical response of perennial ryegrass to P deficiency has been limited, particularly in relation to the early response mechanisms. This study aimed to identify molecular mechanisms activated in response to the initial stages of P deficiency. Methods A barley microarray was successfully used to study gene expression in perennial ryegrass and this was complemented with gas chromatography-mass spectrometry metabolic profiling to obtain an overview of the plant response to early stages of P deficiency. Key Results After 24 h of P deficiency, internal phosphate concentrations were reduced and significant alterations were detected in the metabolome and transcriptome of two perennial ryegrass genotypes. Results indicated a replacement of phospholipids with sulfolipids and the utilization of glycolytic bypasses in response to P deficiency in perennial ryegrass. Conclusions The transcriptome and metabolome of perennial ryegrass undergo changes in response to reductions in P supply after 24 h. PMID:21148585

  6. 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.

  7. High nitrogen supply and carbohydrate content reduce fungal endophyte and alkaloid concentration in Lolium perenne.

    PubMed

    Rasmussen, Susanne; Parsons, Anthony J; Bassett, Shalome; Christensen, Michael J; Hume, David E; Johnson, Linda J; Johnson, Richard D; Simpson, Wayne R; Stacke, Christina; Voisey, Christine R; Xue, Hong; Newman, Jonathan A

    2007-01-01

    The relationship between cool-season grasses and fungal endophytes is widely regarded as mutualistic, but there is growing uncertainty about whether changes in resource supply and environment benefit both organisms to a similar extent. Here, we infected two perennial ryegrass (Lolium perenne) cultivars (AberDove, Fennema) that differ in carbohydrate content with three strains of Neotyphodium lolii (AR1, AR37, common strain) that differ intrinsically in alkaloid profile. We grew endophyte-free and infected plants under high and low nitrogen (N) supply and used quantitative PCR (qPCR) to estimate endophyte concentrations in harvested leaf tissues. Endophyte concentration was reduced by 40% under high N supply, and by 50% in the higher sugar cultivar. These two effects were additive (together resulting in 75% reduction). Alkaloid production was also reduced under both increased N supply and high sugar cultivar, and for three of the four alkaloids quantified, concentrations were linearly related to endophyte concentration. The results stress the need for wider quantification of fungal endophytes in the grassland-foliar endophyte context, and have implications for how introducing new cultivars, novel endophytes or increasing N inputs affect the role of endophytes in grassland ecosystems.

  8. ABA inhibits germination but not dormancy release in mature imbibed seeds of Lolium rigidum Gaud.

    PubMed

    Goggin, Danica E; Steadman, Kathryn J; Emery, R J Neil; Farrow, Scott C; Benech-Arnold, Roberto L; Powles, Stephen B

    2009-01-01

    Dormancy release in imbibed annual ryegrass (Lolium rigidum Gaud.) seeds is promoted in the dark but inhibited in the light. The role of abscisic acid (ABA) in inhibition of dormancy release was found to be negligible, compared with its subsequent effect on germination of dormant and non-dormant seeds. Inhibitors of ABA metabolism had the expected effects on seed germination but did not influence ABA concentration, suggesting that they act upon other (unknown) factors regulating dormancy. Although gibberellin (GA) synthesis was required for germination, the influence of exogenous GA on both germination and dormancy release was minor or non-existent. Embryo ABA concentration was the same following treatments to promote (dark stratification) and inhibit (light stratification) dormancy release; exogenous ABA had no effect on this process. However, the sensitivity of dark-stratified seeds to ABA supplied during germination was lower than that of light-stratified seeds. Therefore, although ABA definitely plays a role in the germination of annual ryegrass seeds, it is not the major factor mediating inhibition of dormancy release in imbibed seeds.

  9. Root growth and plant biomass in Lolium perenne exploring a nutrient-rich patch in soil.

    PubMed

    Nakamura, Ryoji; Kachi, Naoki; Suzuki, Jun-Ichirou

    2008-11-01

    We investigated soil exploration by roots and plant growth in a heterogeneous environment to determine whether roots can selectively explore a nutrient-rich patch, and how nutrient heterogeneity affects biomass allocation and total biomass before a patch is reached. Lolium perenne L. plants were grown in a factorial experiment with combinations of fertilization (heterogeneous and homogeneous) and day of harvest (14, 28, 42, or 56 days after transplanting). The plant in the heterogeneous treatment was smaller in its mean total biomass, and allocated more biomass to roots. The distributions of root length and root biomass in the heterogeneous treatment did not favor the nutrient-rich patch, and did not correspond to the patchy distribution of inorganic nitrogen. Specific root length (length/biomass) was higher and root elongation was more extensive both laterally and vertically in the heterogeneous treatment. These characteristics may enable plants to acquire nutrients efficiently and increase the probability of encountering nutrient-rich patches in a heterogeneous soil. However, heterogeneity of soil nutrients would hold back plant growth before a patch was reached. Therefore, although no significant selective root placement in the nutrient-rich patch was observed, plant growth before reaching nutrient-rich patches differed between heterogeneous and homogeneous environments.

  10. Phytostabilization of copper mine tailings with biosolids: implications for metal uptake and productivity of Lolium perenne.

    PubMed

    Santibáñez, Claudia; Verdugo, Cesar; Ginocchio, Rosanna

    2008-05-20

    A greenhouse pot experiment was conducted to evaluate the feasibility of using biosolids and Lolium perenne for the phytostabilization of copper mine tailings and to evaluate the patterns of metal accumulation and translocation in plants. Biosolids were applied either on the surface or mixed with the tailings at rates of 0, 6, and 12% w/w. All pots were seeded with L. perenne and after six months, the plants were harvested and separated into roots and shoots for metal concentrations analyses as well as some physiological characteristics of the plants. In order to correlate the metal content in plant tissues with some chemical properties, the pore-water of the substrates was analyzed for metals, pH and dissolved organic carbon. Results showed that biosolids application increased the dry biomass production of L. perenne and the shoot concentrations of N and chlorophyll. On the other hand, biosolids increased the concentration of Cu and Zn in the pore-water and in plant tissues. Despite this, there were no evident symptoms of phytotoxicity and the concentration of metals was within the normal ranges described for plants and below the maximum tolerable level for animals. In addition, plant tissue analysis showed that the application of biosolids could significantly reduce Mo uptake and shoot accumulation in plants. The metals were taken up by plants in the following order: Cu>Zn>Mo>Cd. The distribution patterns of metals in plants showed that metals were mainly accumulated in the roots and only a small amount of them were transported to the shoots. These results suggest that mixed application of biosolids (6%) and the use of L. perenne could be appropriate for use in programs of phytostabilization of copper mine tailings. However, these results should be tested under field conditions in order to confirm their efficacy under semi-arid Mediterranean climate conditions.

  11. Recovery from drought stress in Lolium perenne (Poaceae): are fungal endophytes detrimental?

    PubMed

    Cheplick, Gregory P

    2004-12-01

    Perennial ryegrass (Lolium perenne) is a cool-season, perennial species widely used for forage and turf. It is often infected by a clandestine, endophytic fungus (Neotyphodium lolii) that has the potential to affect host growth responses to abiotically stressful conditions. In some species, the grass-endophyte symbiosis is mutualistic, but the relationship is reported to be contingent on environmental conditions and host genotype in L. perenne. The objective of this research was to determine the potential effects of endophyte infection on recovery from severe drought stress in variable genotypes of a perennial ryegrass cultivar. Sixteen infected (+E) and 16 uninfected (-E) ramets were planted in the greenhouse for each of 10 ryegrass genotypes. Eight +E and eight -E plants per genotype were exposed to three sequential droughts where water was withheld for 11-14 d, resulting in <5% soil moisture; the others (control) were watered as needed. Response variables were tiller numbers 1 wk and 4 wk after drought, and leaf area and dry mass of shoots and roots 7 wk after drought. In both control and drought, -E plants had more tillers, and greater leaf area and total mass, than +E plants, suggesting a detrimental effect of endophytic fungi. Fungal hyphae survived the drought and were abundant in post-drought, +E plants. The effects of endophytes were specific for particular host genotypes, as exemplified by significant genotype × endophyte interactions. Root : shoot ratio and percent of mass allocated to tiller bases (a rough measure of resource storage) showed genotype × endophyte × drought interactions. There was plasticity for root : shoot ratio and genetic variation in the ability to restore root growth during recovery from drought. For 7 of 10 genotypes, -E plants showed an equal or greater allocation to tiller bases than +E plants following drought recovery, illustrating a cost to endophyte infection for some genotypes. The symbiotic relationship between L

  12. 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

  13. Cloning, expression, and immunological characterization of recombinant Lolium perenne allergen Lol p II.

    PubMed

    Sidoli, A; Tamborini, E; Giuntini, I; Levi, S; Volonté, G; Paini, C; De Lalla, C; Siccardi, A G; Baralle, F E; Galliani, S

    1993-10-15

    The molecular cloning of the cDNA encoding for an isoallergenic form of Lol p II, a major rye grass (Lolium perenne) pollen allergen, was performed by polymerase chain reaction amplification on mRNA extracted from pollen. The amino acid sequence derived from the cDNA was truncated by 4 and 5 residues at the NH2- and COOH-terminal ends, respectively, and differed only in one position from that previously reported. This cDNA was expressed in Escherichia coli by fusion to the carboxyl terminus of the human ferritin H-chain. The molecule was produced in high yields as a soluble protein and was easily purified. The protein retains the multimeric quaternary structure of ferritin, and it exposes on the surface the allergenic moiety, which can be recognized in Western blotting and in enzyme-linked immunosorbent assay experiments by specific IgE from allergic patients. The recombinant allergen was used to analyze the sera of 26 patients allergic to L. perenne compared with control sera. The results were in good agreement with the values obtained with the radioallergosorbent test assay. In addition, histamine release experiments in whole blood from an allergic patient and skin prick tests showed that the recombinant allergen retains some of the biological properties of the natural compound. These findings indicate that the availability of homogeneous recombinant allergens may be useful for the development of more specific diagnostic and therapeutic procedures. Moreover, this expression system may be of more general interest for producing large amounts of soluble protein domains in E. coli.

  14. Molecular genetics of human immune responsiveness to Lolium perenne (rye) allergen, Lol p III.

    PubMed

    Ansari, A A; Freidhoff, L R; Marsh, D G

    1989-01-01

    Lol p II and III are each about 11-kD protein allergens from the pollen of Lolium perenne (rye grass). We have found that human immune responses (IgE and IgG antibodies) to both proteins are significantly associated with HLA-DR3. In addition, the two proteins are cross-reactive with the antibodies in many human sera (about 84% human sera showed the cross-reactivity). We have determined greater than 90% of the amino acid sequences of the two proteins and found that they are at least 54% homologous. Berzofsky found that 75% of the 23 known T cell sites in various proteins had an amphipathic structure. Our analysis by the same method showed that both Lol p II and III have a major region of amphipathicity (at residues 61-67, Lol p III numbering) which might contain sites for binding to an Ia molecule and a T cell receptor. This region is identical between Lol p II and III, except for an Arg-Lys substitution, and could account, in part, for the DR3 association with responsiveness to both molecules. An interesting difference between the two proteins is that immune response to Lol p III is associated with DR5 (in addition to DR3), whereas no DR5 association is found in the case of Lol p II. One possibility is that Lol p III has an additional site which binds to the DR5 Ia molecule. Lol p III indeed has a second highly amphiphathic peptide, 24-30 (Lol p III 24 R P G D T L A 30), which is different and not amphipathic in Lol p II.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Immunochemical studies of Lolium perenne (rye grass) pollen allergens, Lol p I, II, and III.

    PubMed

    Ansari, A A; Kihara, T K; Marsh, D G

    1987-12-15

    It was reported earlier that human immune responses to three perennial rye grass (Lolium perenne) pollen allergens, Lol p I, II, and III, are associated with histocompatibility leukocyte antigen (HLA)-DR3. Rye-allergic people are often concordantly sensitive to all three of these allergens. Since earlier studies suggested that these antigens are non-cross-reactive, their immunologic relatedness by double antibody radioimmunoassay (DARIA) was studied in order to understand further the immunochemical basis for the concordant recognition of the three allergens. Direct binding DARIA studies were performed with human sera from 189 allergic subjects. Inhibition DARIA studies were carried out with 17 human sera from grass-allergic patients who were on grass immunotherapy, one goat anti-serum, and six rabbit antisera. None of the sera detected any significant degree of two-way cross-reactivity between Lol p I and II, or between Lol p I and III. However, the degree of two-way cross-reactivity between Lol p II and III exhibited by individual human and animal antisera varied between undetectable and 100%. In general, the degree of cross-reactivity between Lol p II and III was higher among human sera than among animal sera. Taken together with earlier findings that antibody responses to Lol p I, II and III are associated with HLA-HDR3, and that most Lol p II and III responders are also Lol p I responders, but not vice versa, our present results suggest the following: the HLA-DR3-encoded Ia molecule recognizes a similar immunodominant Ia recognition site (agretope) shared between Lol p I and Lol p II and/or III; in addition, Lol p I appears to contain unique Ia recognition site(s) not present in Lol p II and III. However, further epitope analyses are required to investigate these possibilities.

  16. 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.

  17. 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

  18. Physiological and biochemical responses to manganese toxicity in ryegrass (Lolium perenne L.) genotypes.

    PubMed

    Inostroza-Blancheteau, Claudio; Reyes-Díaz, Marjorie; Berríos, Graciela; Rodrigues-Salvador, Acácio; Nunes-Nesi, Adriano; Deppe, Mariana; Demanet, Rolando; Rengel, Zed; Alberdi, Miren

    2017-04-01

    We studied resistance to manganese (Mn) toxicity under acidic conditions and its relationship with nutrients such as calcium (Ca) and magnesium (Mg) in new perennial ryegrass (Lolium perenne L.) genotypes (One-50, Banquet-II and Halo-AR1) introduced in southern Chile, using the Nui genotype as the reference. Plants were grown in nutrient solution at increased Mn concentrations (0-750 μM) at pH 4.8, and physiological and biochemical features were determined. Under higher Mn concentration, the One-50 genotype had a significantly lower relative growth rate (RGR) of shoots and roots, whereas in the other cultivars this parameter did not change under variable Mn treatments. Increasing the Mn concentration led to an increased Mn concentration in roots and shoots, with Banquet-II and Halo-AR1 having higher Mn in roots than shoots. Shoot Mg and Ca concentrations in all genotypes (except Banquet-II) decreased concomitantly with increasing Mn applications. In contrast to the other genotypes, Banquet-II and Halo-AR1 maintained their net CO2 assimilation rate regardless of Mn treatment, whereas the chlorophyll concentration decreased in all genotypes with the exception of Banquet-II. In addition, lipid peroxidation in Banquet-II roots increased at 150 μM Mn, but decreased at higher Mn concentrations. This decrease was associated with an increase in antioxidant capacity as well as total phenol concentration. Banquet-II and Halo-AR1 appear to be the most Mn-resistant genotypes based on RGR and CO2 assimilation rate. In addition, Mn excess provoked a strong decrease in Ca and Mg concentrations in shoots of the Mn-sensitive genotype, whereas only slight variations in the Mn-resistant genotype were noted. When other evaluated parameters were taken into account, we concluded that among the perennial ryegrass genotypes introduced recently into southern Chile Banquet-II appears to be the most Mn-resistant, followed by Halo-AR1, with One-50 being the most sensitive.

  19. [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

  20. 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.

  1. Metabolomic Study on Idiosyncratic Liver Injury Induced by Different Extracts of Polygonum multiflorum in Rats Integrated with Pattern Recognition and Enriched Pathways Analysis

    PubMed Central

    Li, Chun-Yu; Tu, Can; Gao, Dan; Wang, Rui-Lin; Zhang, Hai-Zhu; Niu, Ming; Li, Rui-Yu; Zhang, Cong-En; Li, Rui-Sheng; Xiao, Xiao-He; Yang, Mei-Hua; Wang, Jia-Bo

    2016-01-01

    Currently, numerous liver injury cases related to a famous Chinese herb- Polygonum Multiflorum (Heshouwu in Chinese) have attracted great attention in many countries. Our previous work showed that Heshouwu-induced hepatotoxicity belonged to idiosyncratic drug-induced liver injury (IDILI). Unfortunately, the components and mechanisms attributed to IDILI of Heshouwu are difficult to determine and thus remain unknown. Attempts to explore puzzles, we prepared the chloroform (CH)-, ethyl acetate (EA)-, and residue (RE) extracts of Heshouwu to investigate IDILI constituents and underlying mechanisms, using biochemistry, histopathology, and metabolomics examinations. The results showed that co-treatment with non-toxic dose of lipopolysaccharide (LPS) and EA extract could result in evident liver injury, indicated by the significant elevation of plasma alanine aminotransferase and aspartate aminotransferase activities, as well as obvious liver histologic damage; whereas other two separated fractions, CH and RE extracts, failed to induce observable liver injury. Furthermore, 21 potential metabolomic biomarkers that differentially expressed in LPS/EA group compared with other groups without liver injury were identified by untargeted metabolomics, mainly involved two pathways: tricarboxylic acid cycle and sphingolipid metabolism. This work illustrated EA extract had close association with the idiosyncratic hepatotoxicity of Heshouwu and provided a metabolomic insight into IDILI of different extracts from Heshouwu. PMID:28018221

  2. Fragments of the key flowering gene GIGANTEA are associated with helitron-type sequences in the Pooideae grass Lolium perenne

    PubMed Central

    Langdon, Tim; Thomas, Ann; Huang, Lin; Farrar, Kerrie; King, Julie; Armstead, Ian

    2009-01-01

    Background Helitrons are a class of transposable elements which have been identified in a number of species of plants, animals and fungi. They are unique in their proposed rolling-circle mode of replication, have a highly variable copy-number and have been implicated in the restructuring of coding sequences both by their insertion into existing genes and by their incorporation of transcriptionally competent gene fragments. Helitron discovery depends on identifying associated DNA signature sequences and comprehensive evaluation of helitron contribution to a particular genome requires detailed computational analysis of whole genome sequence. Therefore, the role which helitrons have played in modelling non-model plant genomes is largely unknown. Results Cloning of the flowering gene GIGANTEA (GI) from a BAC library of the Pooideae grass Lolium perenne (perennial ryegrass) identified the target gene and several GI pseudogene fragments spanning the first five exons. Analysis of genomic sequence 5' and 3' of one these GI fragments revealed motifs consistent with helitron-type transposon insertion, specifically a putative 5'-A↓T-3' insertion site containing 5'-TC and CTAG-3' borders with a sub-terminal 16 bp hairpin. Screening of a BAC library of the closely related grass species Festuca pratensis (meadow fescue) indicated similar helitron-associated GI fragments present in this genome, as well as non-helitron associated GI fragments derived from the same region of GI. In order to investigate the possible extent of ancestral helitron-activity in L. perenne, a methylation-filtered GeneThresher® genomic library developed from this species was screened for potential helitron 3' hairpin sequences associated with a 3'-CTRR motif. This identified 7 potential helitron hairpin-types present between at least 9 and 51 times within the L. perenne methylation-filtered library. Conclusion This represents evidence for a possible ancestral role for helitrons in modelling the genomes

  3. Variability of ribosomal DNA sites in Festuca pratensis, Lolium perenne, and their intergeneric hybrids, revealed by FISH and GISH.

    PubMed

    Ksiazczyk, T; Taciak, M; Zwierzykowski, Z

    2010-01-01

    This study focuses on the variability of chromosomal location and number of ribosomal DNA (rDNA) sites in some diploid and autotetraploid Festuca pratensis and Lolium perenne cultivars, as well as on identification of rDNA-bearing chromosomes in their triploid and tetraploid F. pratensis × L. perenne hybrids. The rDNA loci were mapped using fluorescence in situ hybridization (FISH) with 5S and 25S rDNA probes, and the origin of parental genomes was verified by genomic in situ hybridization (GISH) with L. perenne genomic DNA as a probe, and F. pratensis genomic DNA as a block. FISH detected variation in the number and chromosomal location of both 5S and 45S rDNA sites. In F. pratensis mostly additional signals of 5S rDNA loci occurred, as compared with standard F. pratensis karyotypes. Losses of 45S rDNA loci were more frequent in L. perenne cultivars and intergeneric hybrids. Comparison of the F. pratensis and L. perenne genomes approved a higher number of rDNA sites as well as variation in chromosomal rDNA location in L. perenne. A greater instability of F. pratensis-genome-like and L. perenne-genome-like chromosomes in tetraploid hybrids was revealed, indicating gains and losses of rDNA loci, respectively. Our data indicate that the rDNA loci physically mapped on chromosomes 2 and 3 in F. pratensis and on chromosome 3 in L. perenne are useful markers for these chromosomes in intergeneric Festuca × Lolium hybrids.

  4. 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

  5. Reduction of atherosclerosis in cholesterol-fed rabbits and decrease of expressions of intracellular adhesion molecule-1 and vascular endothelial growth factor in foam cells by a water-soluble fraction of Polygonum multiflorum.

    PubMed

    Yang, Peng-Yuan; Almofti, Mohamad Radwan; Lu, Ling; Kang, Hui; Zhang, Jing; Li, Tie-Jun; Rui, Yao-Cheng; Sun, Lian-Na; Chen, Wan-Sheng

    2005-11-01

    Polygonum multiflorum stilbeneglycoside (PMS) is a water-soluble fraction of Polygonum multiflorum Thunb., one of the most famous tonic traditional Chinese medicines, that has protective effects on the cardiovascular system. The purpose of the present study is to elucidate the effects of PMS on macrophage-derived foam cell functions and the reduction of severity of atherosclerosis in hypercholesterolemic New Zealand White (NZW) rabbits. NZW rabbits were fed for 12 weeks with a normal diet, a high cholesterol diet, or a high cholesterol diet associated with irrigation with different doses of PMS (25, 50, or 100 mg/kg). Treatment of NZW rabbits fed with high cholesterol diet with 100 mg/kg PMS attenuated the increase in plasma cholesterol, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, and plasma triglyceride. Treatment with 50 and 100 mg/kg PMS caused 43% and 60% decrease in atherosclerotic lesioned area ratio to total surface area, respectively. In U937 foam cells, PMS could decrease the high expression of intercellular adhesion molecule (ICAM)-1 protein and the vascular endothelial growth factor (VEGF) protein levels in the medium induced by oxidized lipoprotein when analyzed by flow cytometry. The results proved that PMS is a powerful agent against atherosclerosis and that PMS action could possibly be through the inhibition of the expression of ICAM-1 and VEGF in foam cells.

  6. Anti-proliferative effect of an extract of the root of Polygonum multiflorum Thunb. on MCF-7 human breast cancer cells and the possible mechanisms.

    PubMed

    Chen, Hong-Sheng; Liu, Yan; Lin, Luo-Qiang; Zhao, Jin-Lu; Zhang, Chun-Peng; Jin, Jun-Chao; Wang, Lei; Bai, Ming-Han; Wang, Yi-Chong; Liu, Ming; Shen, Bao-Zhong

    2011-01-01

    The root of Polygonum multiflorum Thunb. (PM) is utilized to treat many diseases associated with aging. Research also indicates that PM inhibits the proliferation of certain types of cancer cells. The aim of the present study was to evaluate the inhibitory effect of PM extract (PME) on the proliferation of MCF-7 cells and to investigate the underlying mechanisms. Inhibition of the proliferation of MCF-7 cells was determined by the MTT assay. Cell cycle distribution and apoptotic rates were evaluated by flow cytometry, and cell cycle and apoptosis-related protein expression was assessed by Western blotting. Apoptotic characteristics of MCF-7 cells were detected by transmission electron microscopy. The present study showed that PME at doses of 100, 150, 200 and 250 µg/ml significantly inhibited proliferation of MCF-7 cells in a time- and dose-dependent manner. Flow cytometry showed that the cell apoptotic rates were 9.1 ± 1.67 and 17.7 ± 2.93% after treatment with 100 and 200 µg/ml PME for 48 h, respectively. The proportions of cells in the G2/M phase were 37.9 ± 1.47 and 42.0 ± 1.71% after treatment with 100 and 200 µg/ml PME for 24 h, respectively. Western blot analysis showed that PME down-regulated the protein expression of Cdc25B and Cdc25C phosphatases accompanied by an increase in phospho-Cdk1, and PME promoted cytochrome c release from mitochondria into the cytosol to activate caspase-9. The present study demonstrated that PME inhibited MCF-7 cell proliferation by inducing cell cycle arrest in the G2/M phase and promoting cell apoptosis. The effects of PME on MCF-7 cells were associated with the modulation of the expression levels of proteins involved in the cell cycle and apoptosis. These data suggest that PME has promise as a treatment against breast cancer by inhibiting the proliferation of cancer cells.

  7. Allelopathic potential of switchgrass (Panicum virgatum L.) on perennial ryegrass (Lolium perenne L.) and alfalfa (Medicago sativa L.).

    PubMed

    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.

  8. Comparison of EDTA-enhanced phytoextraction and phytostabilisation strategies with Lolium perenne on a heavy metal contaminated soil.

    PubMed

    Lambrechts, Thomas; Gustot, Quentin; Couder, Eléonore; Houben, David; Iserentant, Anne; Lutts, Stanley

    2011-11-01

    Phytoremediation is a promising and cost-effective strategy to manage heavy metal polluted sites. In this experiment, we compared simultaneously phytoextraction and phytostabilisation techniques on a Cd and Zn contaminated soil, through monitoring of plant accumulation and leaching. Lolium perenne plants were cultivated for 2 months under controlled environmental conditions in a 27.6 dm(3)-pot experiment allowing the collect of leachates. The heavy metal phytoextraction was promoted by adding Na-EDTA (0.5 g kg(-1) of soil) in watering solution. Phytostabilisation was assessed by mixing soil with steel shots (1%) before L. perenne sowing. Presence of plants exacerbated heavy metal leaching, by improving soil hydraulic conductivity. Use of EDTA for phytoextraction led to higher concentration of heavy metal in shoots. However, this higher heavy metal extraction was insufficient to satisfactory reduce the heavy metal content in soil, and led to important heavy metal leaching induced by EDTA. On the other hand, addition of steel shots efficiently decreased both Cd and Zn mobility, according to 0.01 M CaCl(2) extraction, and leaching. However, improvement of growth conditions by steel shots led to higher heavy metal mass in shoot tissues. Therefore, soil heavy metal mobility and plant metal uptake are not systematically positively correlated.

  9. 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.

  10. Physiological effects of magnetite (Fe3O4) nanoparticles on perennial ryegrass (Lolium perenne L.) and pumpkin (Cucurbita mixta) plants.

    PubMed

    Wang, Huanhua; Kou, Xiaoming; Pei, Zhiguo; Xiao, John Q; Shan, Xiaoquan; Xing, Baoshan

    2011-03-01

    To date, knowledge gaps and associated uncertainties remain unaddressed on the effects of nanoparticles (NPs) on plants. This study was focused on revealing some of the physiological effects of magnetite (Fe(3)O(4)) NPs on perennial ryegrass (Lolium perenne L.) and pumpkin (Cucurbita mixta cv. white cushaw) plants under hydroponic conditions. This study for the first time reports that Fe(3)O(4) NPs often induced more oxidative stress than Fe(3)O(4) bulk particles in the ryegrass and pumpkin roots and shoots as indicated by significantly increased: (i) superoxide dismutase and catalase enzyme activities, and (ii) lipid peroxidation. However, tested Fe(3)O(4) NPs appear unable to be translocated in the ryegrass and pumpkin plants. This was supported by the following data: (i) No magnetization was detected in the shoots of either plant treated with 30, 100 and 500 mg l(-1) Fe(3)O(4) NPs; (ii) Fe K-edge X-ray absorption spectroscopic study confirmed that the coordination environment of Fe in these plant shoots was similar to that of Fe-citrate complexes, but not to that of Fe(3)O(4) NPs; and (iii) total Fe content in the ryegrass and pumpkin shoots treated with Fe(3)O(4) NPs was not significantly increased compared to that in the control shoots.

  11. Competition for /sup 15/N labelled ammonium between Trifolium subterraneum L. and Lolium multiflorium L. when grown in a mixture

    SciTech Connect

    Munoz Espinoza, A.E.

    1985-01-01

    Grasses and legumes are often grown in association in pastures because total herbage yield and forage quality is often higher than a monoculture grass sward. The competitive ability of the forage species for mineral N influences the stability of the mixed pasture. Mt. Barker subterranean clover (Trifolium subterraneum L.) Gulf ryegrass (Lolium multiflorium L.) were grown in pure stands and in mixtures in 3.8 I pots filled with exploded vermiculite to quantity the competition for applied mineral nitrogen (N). The isotope dilution technique using /sup 15/NH/sub 4/ was used. Also, the effect of increasing rates of fertilizer N on nodulation and fixation by subterranean clover and the rate of N uptake of subterranean clover and ryegrass was measured. The acetylene-ethylene technique and nodulation rating were used to examine the effect of N fertilization on fixation and nodulation. The uptake of N fertilizer by subterranean clover and ryegrass in both pure stands and the mixtures increased as the rate of fertilizer N applied increased. When grown in a pure stand, subterranean clover recovered a comparable amount of fertilizer N, but when grown in mixture with ryegrass, subterranean clover recovered from 44 to 364 mg of N. Ryegrass recovered 2 times the amount of labelled N in 6 hours than subterranean clover. The rate of N uptake was not due to differences in root fresh weight or dry weight. Ryegrass appeared to be a better competitor for NH/sub 4/ than subterranean clover because of the greater rate of uptake.

  12. Arsenic extractability and uptake by velvetgrass Holcus lanatus and ryegrass Lolium perenne in variously treated soils polluted by tailing spills.

    PubMed

    Karczewska, Anna; Lewińska, Karolina; Gałka, Bernard

    2013-11-15

    Phytostabilization should be considered as an appropriate phytoremediation technique to restore the area affected by tailing spills in Zloty Stok, where arsenic ores were mined and processed for several centuries. The study aimed to compare the suitability of velvetgrass (Holcus lanatus L.) and ryegrass (Lolium perenne L.) for development of plant cover in that area. Various treatments commonly applied to support phytostabilization were examined. A pot experiment was carried out to assess the effects of soil amendment with phosphate (P), sewage sludge (SS) and iron salts (Fe) on arsenic extractability and its uptake by grass. Four kinds of soil material, containing 356-5350 mg kg(-1) As, were examined. Velvetgrass proved to be more resistant than ryegrass to the toxicity of soil arsenic. Ammonium sulphate extractability of As in soils correlated well with As concentrations in the biomass of both grass species. In three of four tested soils, application of Fe failed to decrease As extractability and to reduce its concentrations in the aboveground parts of grasses. Application of P and SS resulted in increased As solubility in soils, but their effects on plant biomass and As uptake were ambiguous. SS had a strong beneficial influence on the growth of velvetgrass, while such an effect was not observed for ryegrass.

  13. 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.

  14. The role of sulfur- and phosphorus-mobilizing bacteria in biochar-induced growth promotion of Lolium perenne.

    PubMed

    Fox, Aaron; Kwapinski, Witold; Griffiths, Bryan S; Schmalenberger, Achim

    2014-10-01

    Plants rely on microorganisms to mobilize organically and inorganically bound sulfur (S) and phosphorus (P) in which the plant can then readily utilize. The aim of this study was to investigate the role of S- and P-mobilizing bacteria in plant growth promotion in biochar-amended soil, which has been rarely investigated so far. Pot experiments of Lolium perenne were established on S and P limited soil with 1% or 2% biochar (Miscanthus × giganteus) or without biochar (control) for a period of 126 days. Both biochar amendments resulted in significant plant growth promotion. Rhizobacteria capable of growing with (1) S from aromatic sulfonates, (2) P from phosphate esters, (3) P from phosphonates, and (4) P from tri-calcium phosphates as sole source of S or P, respectively, were significantly more abundant in the biochar treatments. 16S rRNA gene-based rhizobacteria community analysis revealed a significant biochar treatment effect. Abundance of nematodes feeding on bacteria was also significantly increased in the biochar treatments. Diversity analysis of rhizospheric asfA and phnJ genes revealed broad sequence diversities in bacterial sulfonate and phosphonate-mineralizing capabilities. These findings suggest that biochar amendment enhances microbially mediated nutrient mobilization of S and P resulting in improved plant growth.

  15. 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.

  16. 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....

  17. Spatial Distribution of Bacterial Communities and Phenanthrene Degradation in the Rhizosphere of Lolium perenne L.

    PubMed Central

    Corgié, S. C.; Beguiristain, T.; Leyval, C.

    2004-01-01

    Rhizodegradation of organic pollutants, such as polycyclic aromatic hydrocarbons, is based on the effect of root-produced compounds, known as exudates. These exudates constitute an important and constant carbon source that selects microbial populations in the plant rhizosphere, modifying global as well as specific microbial activities. We conducted an experiment in two-compartment devices to show the selection of bacterial communities by root exudates and phenanthrene as a function of distance to roots. Using direct DNA extraction, PCR amplification, and thermal gradient gel electrophoresis screening, bacterial population profiles were analyzed in parallel to bacterial counts and quantification of phenanthrene biodegradation in three layers (0 to 3, 3 to 6, and 6 to 9 mm from root mat) of unplanted-polluted (phenanthrene), planted-polluted, and planted-unpolluted treatments. Bacterial community differed as a function of the distance to roots, in both the presence and the absence of phenanthrene. In the planted and polluted treatment, biodegradation rates showed a strong gradient with higher values near the roots. In the nonplanted treatment, bacterial communities were comparable in the three layers and phenanthrene biodegradation was high. Surprisingly, no biodegradation was detected in the section of planted polluted treatment farthest from the roots, where the bacterial community structure was similar to those of the nonplanted treatment. We conclude that root exudates and phenanthrene induce modifications of bacterial communities in polluted environments and spatially modify the activity of degrading bacteria. PMID:15184156

  18. Olivine weathering in soil, and its effects on growth and nutrient uptake in Ryegrass (Lolium perenne L.): a pot experiment.

    PubMed

    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 CO(2) 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 CO(2) 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 CO(2) sequestration of 290 to 2690 kg ha(-1) (29 10(3) to 269 10(3) 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.

  19. 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.

  20. 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.

  1. 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

  2. The photosynthetic acclimation of Lolium perenne growing in a free-air CO2 enrichment (FACE) system

    SciTech Connect

    Bryant, Jonathan B.

    1994-11-01

    Stands of Ryegrass (Lolium perenne L. cv. Bastion) were grown in the field at ambient or elevated (600μmol/mol) CO2 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 CO2 was carried out with a Free-Air CO2 Enrichment (FACE) system which provides the most "realistic" system of CO2 fumigation currently available. Elevated CO2 increased diurnal CO2 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 CO2 - Vcmax as an in vivo measure of RubisCO activity, decreased by between 29 and 35% in high CO2, whilst Jmax, 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, Jmax and, in most cases, Vcmax, 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 CO2. The results are discussed in terms of the limitation imposed on maximizing photosynthetic and growth responses of Ryegrass at elevated CO2, by the ability of perennial species to increase long-term sink capacity under these conditions.

  3. 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

  4. Orthology Guided Assembly in highly heterozygous crops: creating a reference transcriptome to uncover genetic diversity in Lolium perenne.

    PubMed

    Ruttink, Tom; Sterck, Lieven; Rohde, Antje; Bendixen, Christian; Rouzé, Pierre; Asp, Torben; Van de Peer, Yves; Roldan-Ruiz, Isabel

    2013-06-01

    Despite current advances in next-generation sequencing data analysis procedures, de novo assembly of a reference sequence required for SNP discovery and expression analysis is still a major challenge in genetically uncharacterized, highly heterozygous species. High levels of polymorphism inherent to outbreeding crop species hamper De Bruijn Graph-based de novo assembly algorithms, causing transcript fragmentation and the redundant assembly of allelic contigs. If multiple genotypes are sequenced to study genetic diversity, primary de novo assembly is best performed per genotype to limit the level of polymorphism and avoid transcript fragmentation. Here, we propose an Orthology Guided Assembly procedure that first uses sequence similarity (tBLASTn) to proteins of a model species to select allelic and fragmented contigs from all genotypes and then performs CAP3 clustering on a gene-by-gene basis. Thus, we simultaneously annotate putative orthologues for each protein of the model species, resolve allelic redundancy and fragmentation and create a de novo transcript sequence representing the consensus of all alleles present in the sequenced genotypes. We demonstrate the procedure using RNA-seq data from 14 genotypes of Lolium perenne to generate a reference transcriptome for gene discovery and translational research, to reveal the transcriptome-wide distribution and density of SNPs in an outbreeding crop and to illustrate the effect of polymorphisms on the assembly procedure. The results presented here illustrate that constructing a non-redundant reference sequence is essential for comparative genomics, orthology-based annotation and candidate gene selection but also for read mapping and subsequent polymorphism discovery and/or read count-based gene expression analysis.

  5. 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.

  6. 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

  7. 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.

  8. Effect of combined pollution of chromium and benzo(a)pyrene on seed growth of Lolium perenne.

    PubMed

    Chigbo, Chibuike; Batty, Lesley

    2013-01-01

    The single and joint effects of chromium (Cr) and benzo (a) pyrene (B (a) P) on the seed germination and the elongation of root and shoot of Lolium perenne were investigated. Seed germination represents the first important step to effective phytoremediation. Young seedlings may be susceptible to PAH and heavy metal contaminants. The results showed that in solution, increasing concentration of Cr could inhibit the germination rate as well as root and shoot elongation of L. perenne. Also, the increasing concentration of B (a) P (1-4 mg L(-1)) could accelerate the germination rate. The joint toxicity of Cr and B (a) P showed that increasing concentration of Cr and B (a) P had significant antagonistic effect on the germination rate of L. perenne. In the single factor experiments and joint effect tests of Cr and B (a) P on the seedling growth, the root and shoot elongation were inhibited significantly (p<0.05) for higher concentration of Cr whereas increasing concentration of B (a) P accelerated the shoot elongation. There were significant relationships between the concentration of pollutants and root and shoot elongation (p<0.05). Higher concentration of B (a) P with low concentration of Cr had significant antagonistic effect on shoot and root elongation of L. perenne in solution tests. Also, low concentration of B (a) P with increasing concentration of Cr had a significant synergistic effect on shoot elongation. The toxicity effects of Cr and B (a) P to seed germination, root and shoot elongation are-root elongation>shoot elongation>germination rate.

  9. Clade classification of monolignol biosynthesis gene family members reveals target genes to decrease lignin in Lolium perenne.

    PubMed

    van Parijs, F R D; Ruttink, T; Boerjan, W; Haesaert, G; Byrne, S L; Asp, T; Roldán-Ruiz, I; Muylle, H

    2015-07-01

    In monocots, lignin content has a strong impact on the digestibility of the cell wall fraction. Engineering lignin biosynthesis requires a profound knowledge of the role of paralogues in the multigene families that constitute the monolignol biosynthesis pathway. We applied a bioinformatics approach for genome-wide identification of candidate genes in Lolium perenne that are likely to be involved in the biosynthesis of monolignols. More specifically, we performed functional subtyping of phylogenetic clades in four multigene families: 4CL, COMT, CAD and CCR. Essential residues were considered for functional clade delineation within these families. This classification was complemented with previously published experimental evidence on gene expression, gene function and enzymatic activity in closely related crops and model species. This allowed us to assign functions to novel identified L. perenne genes, and to assess functional redundancy among paralogues. We found that two 4CL paralogues, two COMT paralogues, three CCR paralogues and one CAD gene are prime targets for genetic studies to engineer developmentally regulated lignin in this species. Based on the delineation of sequence conservation between paralogues and a first analysis of allelic diversity, we discuss possibilities to further study the roles of these paralogues in lignin biosynthesis, including expression analysis, reverse genetics and forward genetics, such as association mapping. We propose criteria to prioritise paralogues within multigene families and certain SNPs within these genes for developing genotyping assays or increasing power in association mapping studies. Although L. perenne was the target of the analyses presented here, this functional subtyping of phylogenetic clades represents a valuable tool for studies investigating monolignol biosynthesis genes in other monocot species.

  10. Diversity of endophytic bacteria in Lolium perenne and their potential to degrade petroleum hydrocarbons and promote plant growth.

    PubMed

    Kukla, M; Płociniczak, T; Piotrowska-Seget, Z

    2014-12-01

    The aim of this study was to assess the ability of twenty-nine endophytic bacteria isolated from the tissues of ryegrass (Lolium perenne L.) to promote plant growth and the degradation of hydrocarbon. Most of the isolates belonged to the genus Pseudomonas and showed multiple plant growth-promoting abilities. All of the bacteria that were tested exhibited the ability to produce indole-3-acetic acid and were sensitive to streptomycin. These strains were capable of phosphate solubilization (62%), cellulolytic enzyme production (62%), a capacity for motility (55%) as well as for the production of siderophore (45%), ammonium (41%) and hydrogen cyanide (38%). Only five endophytes had the emulsification ability that results from the production of biosurfactants. The 1-aminocyclopropane-1-carboxylate deaminase (ACCD) gene (acdS) was found in ten strains. These bacteria exhibited ACCD activities in the range from 1.8 to 56.6 μmol of α-ketobutyrate mg(-1)h(-1), which suggests that these strains may be able to modulate ethylene levels and enhance plant growth. The potential for hydrocarbon degradation was assessed by PCR amplification on the following genes: alkH, alkB, C23O, P450 and pah. The thirteen strains that were tested had the P450 gene but the alkH and pah genes were found only in the Rhodococcus fascians strain (L11). Four endophytic bacteria belonging to Microbacterium sp. and Rhodococcus sp. (L7, S12, S23, S25) showed positive results for the alkB gene.

  11. 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

  12. Comparison of sensitivity of grasses (Lolium perenne L. and Festuca rubra L.) and lettuce (Lactuca sativa L.) exposed to water contaminated with microcystins.

    PubMed

    Pereira, Silvia; Saker, Martin L; Vale, Micaela; Vasconcelos, Vitor M

    2009-07-01

    The effects of aqueous extracts from Microcysts aeruginosa strains (both microcystin-producers and non-microcystin producers) on germination and root growth were investigated for three economically important plant species: Festuca rubra L., Lolium perenne L., and Lactuca sativa L. There was a clear inhibition of root growth for L. sativa exposed to strains containing microcystins (5.9-56.4 microg L(-1)). The strain that produced the most pronounced effects contained the lowest concentration of microcystin suggesting that other cellular compounds may also affect growth.

  13. Immunological cross-reactivity of the major allergen from perennial ryegrass (Lolium perenne), Lol p I, and the cysteine proteinase, bromelain.

    PubMed

    Pike, R N; Bagarozzi, D; Travis, J

    1997-04-01

    Antibodies prepared in rabbits against the major allergen from ryegrass (Lolium perenne), Lol p I, cross-reacted with the cysteine proteinase bromelain from pineapple and vice versa. Deglycosylation of the proteins showed that the cross-reaction was based on recognition of the carbohydrate moiety of the allergen, but for bromelain the cross-reaction was most likely due to a combination of factors. The results indicate that the carbohydrate residues from these allergens play an important role in cross-reactions found between them and possibly those from other species.

  14. An Epichloë festucae homologue of MOB3, a component of the STRIPAK complex, is required for the establishment of a mutualistic symbiotic interaction with Lolium perenne

    PubMed Central

    Green, Kimberly A.; Becker, Yvonne; Fitzsimons, Helen L.

    2016-01-01

    Summary In both Sordaria macrospora and Neurospora crassa, components of the conserved STRIPAK (striatin‐interacting phosphatase and kinase) complex regulate cell–cell fusion, hyphal network development and fruiting body formation. Interestingly, a number of Epichloë festucae genes that are required for hyphal cell–cell fusion, such as noxA, noxR, proA, mpkA and mkkA, are also required for the establishment of a mutualistic symbiotic interaction with Lolium perenne. To determine whether MobC, a homologue of the STRIPAK complex component MOB3 in S. macrospora and N. crassa, is required for E. festucae hyphal fusion and symbiosis, a mobC deletion strain was generated. The ΔmobC mutant showed reduced rates of hyphal cell–cell fusion, formed intrahyphal hyphae and exhibited enhanced conidiation. Plants infected with ΔmobC were severely stunted. Hyphae of ΔmobC showed a proliferative pattern of growth within the leaves of Lolium perenne with increased colonization of the intercellular spaces and vascular bundles. Although hyphae were still able to form expressoria, structures allowing the colonization of the leaf surface, the frequency of formation was significantly reduced. Collectively, these results show that the STRIPAK component MobC is required for the establishment of a mutualistic symbiotic association between E. festucae and L. perenne, and plays an accessory role in the regulation of hyphal cell–cell fusion and expressorium development in E. festucae. PMID:27277141

  15. 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

  16. [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.

  17. 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.

  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 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

  19. Mapping of T cell epitopes of the major fraction of rye grass using peripheral blood mononuclear cells from atopics and non-atopics. II. Isoallergen clone 5A of Lolium perenne group I (Lol p I).

    PubMed

    Bungy, G A; Rodda, S; Roitt, I; Brostoff, J

    1994-09-01

    Rye grass is the major cause of hay fever which currently affects 20% of the population. Lolium perenne group I (Lol p I) is a glycoprotein of 240 amino acid residues, representing the main allergen of rye grass. We have used peripheral blood mononuclear cells (PBMC) from controls and subjects allergic to rye grass and cultured them with L. perenne extract (LPE) and Lol p I and measured lymphocyte activation using thymidine incorporation. Patients were further studied against the 115 overlapping peptides of the iso-allergen clone 5A of Lol p I to see whether the 4 amino acid residue differences between clone 1A and clone 5A affect the T cell epitope and thus, lymphocyte activation. There are 24 peptide differences between isoallergen clone 1A and clone 5A occurring in pools 4, 13, 16 and 19 each one of which could be an immunodominant epitope. The PBMC from all allergic patients studied showed a strong proliferative response to LPE and Lol p I. Five immunogenic peptide pools, pool 6, 15, 16, 17 and 19 of the isoallergen clone 5A were also identified. Most of these pools are in the C-terminal region of Lol p I. Out of 20 pools tested in vitro 1 pool (pool-17) induced PBMC proliferation in five out of six patients who were not restricted to an HLA class II DR gene product. However, three out of the six subjects responded to various other peptide pools in addition to the immunodominant pool. In spite of the amino acid differences between the two clones, pool 17 still remains the immunodominant T cell epitope. Control subjects showed only weak responses to LPE and no detectable response to either Lol p I or peptide pools. From within the most active pool we have defined two peptides of the isoallergen clone 5A (identical in sequence with clone 1A) which stimulate lymphocytes from rye grass-sensitive patients in vitro. Previous studies with the two continuous sequences (193WGAVWRIDTPDK204 and 195AVWRIDTPDKLT206) tested in vivo by intradermal skin testing have shown

  20. Effect of pre-grazing herbage mass on dairy cow performance, grass dry matter production and output from perennial ryegrass (Lolium perenne L.) pastures.

    PubMed

    Wims, C M; Delaby, L; Boland, T M; O'Donovan, M

    2014-01-01

    A grazing study was undertaken to examine the effect of maintaining three levels of pre-grazing herbage mass (HM) on dairy cow performance, grass dry matter (DM) production and output from perennial ryegrass (Lolium perenne L.) pastures. Cows were randomly assigned to one of three pre-grazing HM treatments: 1150 - Low HM (L), 1400 - Medium HM (M) or 2000 kg DM/ha - High HM (H). Herbage accumulation under grazing was lowest (P<0.01) on the L treatment and cows grazing the L pastures required more grass silage supplementation during the grazing season (+73 kg DM/cow) to overcome pasture deficits due to lower pasture growth rates (P<0.05). Treatment did not affect daily milk production or pasture intake, although cows grazing the L pastures had to graze a greater daily area (P<0.01) and increase grazing time (P<0.05) to compensate for a lower pre-grazing HM (P<0.01). The results indicate that, while pre-grazing HM did not influence daily milk yield per cow, adapting the practise of grazing low HM (1150 kg DM/ha) pasture reduces pasture DM production and at a system level may increase the requirement for imported feed.

  1. 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.

  2. 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

  3. Stable isotope tracing: a powerful tool for selenium speciation and metabolic studies in non-hyperaccumulator plants (ryegrass Lolium perenne L.).

    PubMed

    Di Tullo, Pamela; Versini, Antoine; Bueno, Maïté; Le Hécho, Isabelle; Thiry, Yves; Biron, Philippe; Castrec-Rouelle, Maryse; Pannier, Florence

    2015-12-01

    Selenium is both essential and toxic for mammals; the range between the two roles is narrow and not only dose-dependent but also related to the chemical species present in foodstuff. Unraveling the metabolism of Se in plants as a function of Se source may thus lead to ways to increase efficiency of fertilization procedures in selenium deficient regions. In this study, stable-isotope tracing was applied for the first time in plants to simultaneously monitor the bio-incorporation of two inorganic Se species commonly used as foodstuff enrichment sources. Occurrence and speciation of Se coming from different Se sources were investigated in root and leaf extracts of ryegrass (Lolium perenne L.), which had been co-exposed to two labeled Se species ((77)SeIV and (82)SeVI). Although the plant absorbed similar amounts of Se when supplied in the form of selenite or selenate, the results evidenced marked differences in speciation and tissues allocation. Selenite was converted into organic forms incorporated mostly into high molecular weight compounds with limited translocation to leaves, whereas selenate was highly mobile being little assimilated into organic forms. Double-spike isotopic tracer methodology makes it possible to compare the metabolism of two species-specific Se sources simultaneously in a single experiment and to analyze Se behavior in not-hyperaccumulator plants, the ICP-MS sensitivity being improved by the use of enriched isotopes.

  4. 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.

  5. Wood pellet fly ash and bottom ash as an effective liming agent and nutrient source for rye grass (Lolium perenne L.) and oats (Avena sativa).

    PubMed

    Park, Nathan D; Michael Rutherford, P; Thring, Ronald W; Helle, Steve S

    2012-01-01

    Fly ash (FA) and bottom ash (BA) from a softwood pellet boiler were characterized and evaluated as soil amendments. In a greenhouse study, two plant species (rye grass, Lolium perenne L. and oats, Avena sativa) were grown in three different treatments (1% FA, 1% BA, non-amended control) of a silty loam soil. Total concentrations of plant nutrients Ca, K, Mg, P and Zn in both ashes were elevated compared to conventional wood ash. Concentrations of Cd, Cr, Pb, Se and Zn were found to be elevated in the FA relative to BA and the non-amended soil. At 28 d, oat above-ground biomass was found to be significantly greater in soil amended with FA. Potassium and Mo plant tissue concentrations were significantly increased by addition of either ash, and FA significantly increased Zn tissue concentrations. Cadmium and Hg tissue concentrations were elevated in some cases. As soil amendments, either pellet ash is an effective liming agent and nutrient source, but high concentrations of Cd and Zn in FA may preclude its use as an agricultural soil amendment in some jurisdictions. Lower ash application rates than those used in this study (i.e. <1%) may still provide sufficient nutrients and effective neutralization of soil acidity.

  6. Human immune responsiveness to Lolium perenne pollen allergen Lol p III (rye III) is associated with HLA-DR3 and DR5.

    PubMed

    Ansari, A A; Freidhoff, L R; Meyers, D A; Bias, W B; Marsh, D G

    1989-05-01

    A well-characterized allergen of Lolium perenne (perennial rye grass) pollen, Lol p III, has been used as a model antigen to study the genetic control of the human immune response. Associations between HLA type and IgE or IgG antibody (Ab) responsiveness to Lol p III were studied in two groups of skin-test-positive Caucasoid adults (N = 135 and 67). We found by nonparametric and parametric analyses that immune responsiveness to Lol p III was significantly associated with HLA-DR3 and DR5. No association was found between any DQ type and immune responsiveness to Lol p III. Geometric mean IgE or IgG Ab levels to Lol p III were not different between B8+, DR3+ subjects and B8-, DR3+ subjects, showing that HLA-B8 had no influence on the association. Lol p III IgG Ab data obtained on subjects after grass antigen immunotherapy showed that 100% of DR3 subjects and 100% of DR5 subjects were Ab+. A comparison of all the available protein sequences of DRB gene products showed that the first hypervariable region of DR3 and DR5 (and DRw6), and no other region, contains the sequence Glu9-Tyr-Ser-Thr-Ser13. Our observations are consistent with the possibility that immune responsiveness to the allergen Lol p III is associated with this amino acid sequence in the first hypervariable region of the DR beta 1 polypeptide chain.

  7. Complete primary structure of a Lolium perenne (perennial rye grass) pollen allergen, Lol p III: comparison with known Lol p I and II sequences.

    PubMed

    Ansari, A A; Shenbagamurthi, P; Marsh, D G

    1989-10-17

    The complete amino acid sequence of a Lolium perenne (rye grass) pollen allergen, Lol p III, determined by the automated Edman degradation of the protein and its selected fragments, is reported in this paper. Cleavage by enzymatic and chemical techniques established unambiguously the sequence for this 97-residue protein (Mr = 10,909), which lacks cysteine and shows no evidence of glycosylation. The sequence of Lol p III is very similar to that of another L. perenne allergen, Lol p II, which was sequenced recently; of the 97 positions in the two proteins, 57 are occupied by identical amino acids (59% identity). In addition, both allergens share a similar structure with an antibody-binding fragment of a third L. perenne allergen, Lol p I. Since human antibody responsiveness to all these three allergens is associated with HLA-DR3, and since the structure common to the three molecules shows high degrees of amphipathicity in Lol p II and III, we speculate that this common segment in the three molecules might contain or contribute to the respectively Ia/T-cell sites.

  8. Variations in efficiency of plastidial RNA editing within ndh transcripts of perennial ryegrass (Lolium perenne) are not linked to differences in drought tolerance

    PubMed Central

    Van Den Bekerom, Rob J. M.; Dix, Philip J.; Diekmann, Kerstin; Barth, Susanne

    2013-01-01

    Maintenance of healthy grasslands is essential for efficient livestock production, yet projected climate change is likely to place a heavy drought stress burden on key grassland species, such as perennial ryegrass (Lolium perenne). It is therefore important to gather an in-depth knowledge of the underlying plant response to this stress. The present study is focused on RNA editing (post-transcriptional nucleotide modifications resulting in altered transcripts) within plastidial transcripts of the NADH:ubiquinone oxidoreductase (NDH) complex (NADH dehydrogenase complex) in relation to the drought response of several accessions of perennial ryegrass. Previous studies have shown that the NDH complex is involved in countering oxidative stress during environmental stresses like drought. Owing to the nature of RNA editing within this complex, the RNA editing machinery could play a potential role in regulating the activity of the NDH complex. The investigation revealed dramatic and reproducible differences in RNA editing efficiency between accessions, but efficiency was not influenced by imposition of drought stress, and a direct relationship between editing behaviour and drought response was not detected.

  9. 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

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

    2015-08-01

    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.

  10. Nitrogen deficiency inhibits leaf blade growth in Lolium perenne by increasing cell cycle duration and decreasing mitotic and post-mitotic growth rates.

    PubMed

    Kavanová, Monika; Lattanzi, Fernando Alfredo; Schnyder, Hans

    2008-06-01

    Nitrogen deficiency severely inhibits leaf growth. This response was analysed at the cellular level by growing Lolium perenne L. under 7.5 mM (high) or 1 mM (low) nitrate supply, and performing a kinematic analysis to assess the effect of nitrogen status on cell proliferation and cell growth in the leaf blade epidermis. Low nitrogen supply reduced leaf elongation rate (LER) by 43% through a similar decrease in the cell production rate and final cell length. The former was entirely because of a decreased average cell division rate (0.023 versus 0.032 h(-1)) and thus longer cell cycle duration (30 versus 22 h). Nitrogen status did not affect the number of division cycles of the initial cell's progeny (5.7), and accordingly the meristematic cell number (53). Meristematic cell length was unaffected by nitrogen deficiency, implying that the division and mitotic growth rates were equally impaired. The shorter mature cell length arose from a considerably reduced post-mitotic growth rate (0.033 versus 0.049 h(-1)). But, nitrogen stress did not affect the position where elongation stopped, and increased cell elongation duration. In conclusion, nitrogen deficiency limited leaf growth by increasing the cell cycle duration and decreasing mitotic and post-mitotic elongation rates, delaying cell maturation.

  11. Functional Analyses of Caffeic Acid O-Methyltransferase and Cinnamoyl-CoA-Reductase Genes from Perennial Ryegrass (Lolium perenne)[W

    PubMed Central

    Tu, Yi; Rochfort, Simone; Liu, Zhiqian; Ran, Yidong; Griffith, Megan; Badenhorst, Pieter; Louie, Gordon V.; Bowman, Marianne E.; Smith, Kevin F.; Noel, Joseph P.; Mouradov, Aidyn; Spangenberg, German

    2010-01-01

    Cinnamoyl CoA-reductase (CCR) and caffeic acid O-methyltransferase (COMT) catalyze key steps in the biosynthesis of monolignols, which serve as building blocks in the formation of plant lignin. We identified candidate genes encoding these two enzymes in perennial ryegrass (Lolium perenne) and show that the spatio-temporal expression patterns of these genes in planta correlate well with the developmental profile of lignin deposition. Downregulation of CCR1 and caffeic acid O-methyltransferase 1 (OMT1) using an RNA interference–mediated silencing strategy caused dramatic changes in lignin level and composition in transgenic perennial ryegrass plants grown under both glasshouse and field conditions. In CCR1-deficient perennial ryegrass plants, metabolic profiling indicates the redirection of intermediates both within and beyond the core phenylpropanoid pathway. The combined results strongly support a key role for the OMT1 gene product in the biosynthesis of both syringyl- and guaiacyl-lignin subunits in perennial ryegrass. Both field-grown OMT1-deficient and CCR1-deficient perennial ryegrass plants showed enhanced digestibility without obvious detrimental effects on either plant fitness or biomass production. This highlights the potential of metabolic engineering not only to enhance the forage quality of grasses but also to produce optimal feedstock plants for biofuel production. PMID:20952635

  12. 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

  13. Effect of DA-6 and EDTA alone or in combination on uptake, subcellular distribution and chemical form of Pb in Lolium perenne.

    PubMed

    He, Shanying; Wu, Qiuling; He, Zhenli

    2013-11-01

    The effects of growth-promoting hormone diethyl aminoethyl hexanoate (DA-6) and EDTA, either alone or in combination applied to original soil or lead (Pb) spiked soil on Pb phytoextraction, subcellular distribution and chemical forms in Lolium perenne were studied. EDTA addition alone significantly reduced plant biomass though it increased Pb accumulation (P<0.05). Foliar spray of DA-6 alone increased both plant biomass and Pb accumulation (P<0.05), with 10μM DA-6 being the most effective. DA-6 combined with EDTA compensated the adverse effect of the latter on plant growth, and resulted in a synergistic effect on Pb uptake and translocation, with the maximum accumulation occurring in the EDTA+10μM DA-6 treatment. At the subcellular level, about 35-66% of Pb was distributed in cell wall and 21-42% in soluble fraction, with a minority present in cellular organelles fraction. EDTA addition alone increased the proportion of Pb in soluble and cellular organelles fraction, while DA-6 detoxified Pb in plant by storing additional Pb in cell wall, and 10μM DA-6 was the most effective. Of the total Pb in plant shoot, 27-52% was NaCl extractable, 22-47% HAc extractable, followed by other fractions. Contrary to EDTA, DA-6 significantly decreased Pb migration in plant. These results suggest that Pb fixation by pectates and proteins in cell wall and compartmentalization by vacuole might be responsible for Pb detoxification in plant, and the combined use of EDTA and 10μM DA-6 appears to be optimal for improving the remediation efficiency of L. perenne for Pb contaminated soil.

  14. 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.

  15. 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.

  16. Cloning, gene mapping, and functional analysis of a fructan 1-exohydrolase (1-FEH) from Lolium perenne implicated in fructan synthesis rather than in fructan mobilization.

    PubMed

    Lothier, Jérémy; Lasseur, Bertrand; Le Roy, Katrien; Van Laere, André; Prud'homme, Marie-Pascale; Barre, Philippe; Van den Ende, Wim; Morvan-Bertrand, Annette

    2007-01-01

    Fructans, which are beta-(2,1) and/or beta-(2,6) linked polymers of fructose, are important storage carbohydrates in many plants. They are mobilized via fructan exohydrolases (FEHs). The cloning, mapping, and functional analysis of the first 1-FEH (EC 3.2.1.153) from Lolium perenne L. var. Bravo is described here. By screening a perennial ryegrass cDNA library, a 1-FEH cDNA named Lp1-FEHa was cloned. The Lp1-FEHa deduced protein has a low iso-electric point (5.22) and it groups together with plant FEHs and cell-wall type invertases. The deduced amino acid sequence shows 75% identity to wheat 1-FEH w2. The Lp1-FEHa gene was mapped at a distal position on the linkage group 3 (LG3). Functional characterization of the recombinant protein in Pichia pastoris demonstrated that it had high FEH activity towards 1-kestotriose, 1,1-kestotetraose, and inulin, but low activity against 6-kestotriose and levan. Like other fructan-plant FEHs, no hydrolase activity could be detected towards sucrose, convincingly demonstrating that the enzyme is not a classic invertase. The expression pattern analysis of Lp1-FEHa revealed transcript accumulation in leaf tissues accumulating fructans while transcript level was low in the photosynthetic tissues. The high expression level of this 1-FEH in conditions of active fructan synthesis, together with its low expression level when fructan contents are low, suggest that it might play a role as a beta-(2,1) trimming enzyme acting during fructan synthesis in concert with fructan synthesis enzymes.

  17. Study of the epitope structure of purified Dac G I and Lol p I, the major allergens of Dactylis glomerata and Lolium perenne pollens, using monoclonal antibodies.

    PubMed

    Mourad, W; Mécheri, S; Peltre, G; David, B; Hébert, J

    1988-11-15

    The use of mAb allowed us to further analyze the cross-reactivity between purified Dac g I and Lol p I, the major allergens of Dactylis glomerata (cocksfoot) and Lolium perenne (Rye grass), respectively. It was first shown, using IEF, followed by immunoprinting, that serum IgE antibodies from most grass-sensitive patients recognize both Dac g I and Lol p I. Second, three different anti-Lol p I mAb, 290A-167, 348A-6, and 539A-6, and one anti-Dac g I mAb, P3B2 were all shown to react with Dac g I and Lol p I, indicating that the two molecules share common epitopes. Epitope specificity of the mAb was determined by competitive binding inhibition of a given labeled mAb to solid phase fixed Dac g I or Lol p I by the mAb. The results indicated that the four mAb are directed against four different and non-overlapping epitopes present on both allergens. Using double-binding RIA, our data strongly suggest that the common epitopes are not repetitive on both molecules. In addition to their similar physicochemical characteristics, such as isolectric points and m.w., Dac g I and Lol p I share four identical epitopes. Binding inhibition of human IgE to Lol p I and Dac g I by the mAb was also assessed. The results indicated that each mAb was able to inhibit such reactions to variable degree but no additive inhibition was observed when two mAb of different specificities were used in combination, suggesting that the human IgE binding site is partially shared by each epitope recognized by the four mAb.

  18. 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.

  19. Responses of antioxidant gene, protein and enzymes to salinity stress in two genotypes of perennial ryegrass (Lolium perenne) differing in salt tolerance.

    PubMed

    Hu, Longxing; Li, Huiying; Pang, Huangcheng; Fu, Jinmin

    2012-01-15

    Salinity could damage cellular membranes through overproduction of reactive oxygen species (ROS), while antioxidant capacities play a vital role in protecting plants from salinity caused oxidative damages. The objective of this study was to investigate the toxic effect of salt on the antioxidant enzyme activities, isoforms and gene expressions in perennial ryegrass (Lolium perenne L.). Salt-tolerant 'Quickstart II' and salt-sensitive 'DP1' were subjected to 0 and 250 mM NaCl for 12 d. Salt stress increased the content of lipid peroxidation (MDA), electrolyte leakage (EL) and hydrogen peroxide (H₂O₂), to a greater extent in salt-sensitive genotype. Salt-stressed plant leaves exhibited a greater activity of superoxide dismutase (SOD, EC 1.15.1.1), peroxidase (POD, EC 1.11.1.7), ascorbate peroxidase (APX, EC 1.11.1.11) at 4d after treatment (DAT), but a lower level of enzyme activity at 8 and 12d, when compared to the control. Catalase (CAT, EC 1.11.1.6) activity was greater at 4 DAT and thereafter decreased in salt tolerant genotype relative to the control, whereas lower than the control during whole experiment period for salt-sensitive genotype. There were different patterns of five isoforms of SOD, POD and two isoforms of APX between two genotypes. Antioxidant gene expression was positively related to isoenzymatic and total enzymatic activities during 12-d salt-treated leaves of two genotypes, with a relatively higher level in salt-tolerant genotype. Thus, salt tolerance could be related to the constitutive/induced antioxidant gene, leading to more efficient enzyme stimulation and protection in perennial ryegrass.

  20. Effect of elevated CO₂ and temperature on the oxidative stress response to drought in Lolium perenne L. and Medicago sativa L.

    PubMed

    Farfan-Vignolo, Evelyn Roxana; Asard, Han

    2012-10-01

    Studies addressing the combined impact of multiple climate factors on plant abiotic stress responses are still scarce. We investigated physiological and molecular (antioxidant), responses to water deficit, in grassland-model species, Lolium perenne L. and Medicago lupulina L., under future climate conditions, i.e. elevated CO₂ (+CO₂, +375 ppm) and elevated temperature (+T, +3 °C). Elevated CO₂, but not warming, significantly increased biomass (gDW) in L. perenne, but not in M. lupulina. Photosynthesis (A(sat)) and stomatal conductance (g(s)), were differently affected by climate in each species, L. perenne generally being more sensitive. Elevated CO₂ increased lipid peroxidation levels in M. lupulina, but not in L. perenne, and had no effect on protein oxidation and little effect on antioxidant levels. Drought stress caused severe inhibition in biomass and photosynthesis, most severely in L. perenne, and strongly increased oxidative damage. Elevated CO₂ protected against the drought-induced damage. Decreased activities of APX and POX may indicate lower levels of oxidative challenge (relaxation) at the level of H₂O₂ production. Polyphenols, tocopherols and antioxidant capacity, increased under drought stress, in all climate conditions. Elevated CO₂, increased reduced ascorbate (ASC) and reduced glutathione (GSH), and their redox status, in both species, although to different levels. Changes in activities of key ASC/GSH cycle enzymes, under stress and climate treatments, showed weak correlations with ASC and GSH levels, indicating the complexity of this network. Together this work supports the idea that redox changes are involved in responses to climate changes, in the absence and presence of water-deficit stress.

  1. Nutrient Availability and Atmospheric CO2 Partial Pressure Modulate the Effects of Nutrient Heterogeneity on the Size Structure of Populations in Grassland Species

    PubMed Central

    MAESTRE, FERNANDO T.; REYNOLDS, JAMES F.

    2006-01-01

    • Background and Aims Size-asymmetric competition occurs when larger plants have a disproportionate advantage in competition with smaller plants. It has been hypothesized that nutrient heterogeneity may promote it. Experiments testing this hypothesis are inconclusive, and in most cases have evaluated the effects of nutrient heterogeneity separately from other environmental factors. The aim of this study was to test, using populations of Lolium perenne, Plantago lanceolata and Holcus lanatus, two hypotheses: (a) nutrient heterogeneity promotes size-asymmetric competition; and (b) nutrient heterogeneity interacts with both atmospheric CO2 partial pressure (PCO2) and nutrient availability to determine the magnitude of this response. • Methods Microcosms consisting of monocultures of the three species were grown for 90 d in a factorial experiment with the following treatments: PCO2 (37·5 and 70 Pa) and nutrient availability (NA; 40 and 120  mg of N added as organic material) combined with different spatial distribution of the organic material (NH; homogeneous and heterogeneous). Differences in the size of individual plants within populations (size inequality) were quantified using the coefficient of variation of individual above-ground biomass and the combined biomass of the two largest individuals in each microcosm. Increases in size inequality were associated with size-asymmetric competition. • Key Results Size inequality increased when the nutrients were heterogeneously supplied in the three species. The effects of NH on this response were more pronounced under high nutrient supply in both Plantago and Holcus (significant NA × NH interactions) and under elevated PCO2 in Plantago (significant PCO2 × NA × NH interaction). No significant two- and three-way interactions were found for Lolium. • Conclusions Our first hypothesis was supported by our results, as nutrient heterogeneity promoted size-asymmetric competition in the three species evaluated

  2. 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

  3. Effects of elevated ultraviolet radiation and endophytic fungi on plant growth and insect feeding in Lolium perenne, Festuca rubra, F. arundinacea and F. pratensis.

    PubMed

    McLeod, A R; Rey, A; Newsham, K K; Lewis, G C; Wolferstam, P

    2001-09-01

    Plants of perennial ryegrass (Lolium perenne L.), red fescue (Festuca rubra L.), tall fescue (F. arundinacea Schreb.) and meadow fescue (F. pratensis Huds) were exposed at an outdoor facility located in Edinburgh, UK to modulated levels of UV-B radiation (280-315 nm) using banks of cellulose diacetate filtered UV-B fluorescent lamps that also produce UV-A radiation (315-400 nm). The plants were derived from a single clone of each species and were grown both with and without colonization by naturally-occurring fungal endophytes. The UV-B treatment was a 30% elevation above the ambient erythemally-weighted level of UV-B during July to October. Growth of treated plants was compared with plants grown under elevated UV-A radiation alone produced by banks of polyester filtered lamps and with plants grown at ambient levels of solar radiation under banks of unenergized lamps. At the end of the treatment period, sample leaves were collected for feeding trials with the desert locust Schistocerca gregaria (Forsk). The UV-B treatment produced no effects on the aboveground biomass of any of the four grasses. The UV-B treatment and the UV-A control exposure both increased plant height and the number of daughter plants formed by rhizome growth in F. rubra. There were significant effects of endophyte presence on the total fresh and dry weights of F. arundinacea and F. rubra, on fresh weight only in F. pratensis, and on the fresh and dry weights of inflorescence in F. arundinacea and L. perenne. There were no effects of UV treatments on the absolute amounts of leaf consumed or on the feeding preferences of locusts for leaves with or without endophyte in three species: F. rubra, F. arundinacea and L. perenne. In F. pratensis there was no effect of UV treatment on the weight of leaves consumed but a significant UV x endophyte interaction caused by a marked change in feeding preference between leaves with and without endophyte that differed between the UV-B treatment and UV-A control

  4. A review of the Neotyphodium lolii / Lolium perenne symbiosis and its associated effects on animal and plant health, with particular emphasis on ryegrass staggers.

    PubMed

    di Menna, M E; Finch, S C; Popay, A J; Smith, B L

    2012-11-01

    Ryegrass staggers is a seasonal mycotoxicosis of grazing livestock characterised by tremors, in coordination and a staggering gait almost unaccompanied by physical lesions. Deaths occur only as a consequence of accident or starvation. Outbreaks, in summer and autumn, occur only on pasture in which endophyte (Neotyphodium lolii)-infected perennial ryegrass (Lolium perenne) predominates and usually on which animals are grazed intensively. Animals recover when moved to a different type of grazing or after rain has promoted pasture growth. The disease was recognised for 80 years before its cause was discovered as a consequence of a grazing trial of sheep on three ryegrass cultivars which happened to have three different levels of endophyte infection. The endophyte was first formally described as Acremonium loliae, later corrected to Acremonium lolii, and was finally placed in the genus Neotyphodium. It produces a number of secondary metabolites of which lolitrem B is the principal one causing ryegrass staggers symptoms. Ergopeptides are also produced which cause heat stress and lack of productivity. N. lolii is symptomless in the plant, seed borne and grows intercellularly in the aerial parts, mainly in reproductive tillers and leaf sheaths but sparsely in leaf blades. It dies in stored seed and infection rates of different ryegrass cultivars have depended on seed storage times during their production. In addition, N. Lolii produces insect feeding deterrents, among them peramine, which protects infected plants from pest predation. Because of this, control of ryegrass staggers by elimination of endophyte-infected ryegrass is not feasible in areas in which insect predation is a serious pasture problem. However, N. lolii strains vary in the secondary metabolites they produce allowing the selection of strains that produce desirable metabolites. By inoculating such strains into uninfected ryegrass plants it is possible to produce cultivars which do not cause ryegrass

  5. The photosynthetic acclimation of Lolium perenne in response to three years growth in a free-air CO2 enrichment (FACE) system

    SciTech Connect

    Hymus, Graham J.

    1996-08-01

    Pure stands of Ryegrass were in their third year of growth in the field, exposed to either ambient (355 μmol mol-1), or elevated (600 μmol mol-1) atmospheric CO2 concentration. A Free-Air CO2 Enrichment (FACE) system was used to maintain the elevated CO2 concentration whilst limiting experimental constraints on the field conditions. The theoretically predicted increase in the net rates of CO2 uptake per unit leaf area (A {mu}mol mol-1) as a consequence, primarily, of the suppression of photorespiration by CO2 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 CO2. 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 Vcmax as a measure of the maximum in vivo carboxylation capacity of the primary carboxylasing enzyme Rubisco and Jmax 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 C3 crops being able to adapt physiologically to maximize the potential benefits conferred by growth in elevated CO2.

  6. Transcript profiling of fructan biosynthetic pathway genes reveals association of a specific fructosyltransferase isoform with the high sugar trait in Lolium perenne.

    PubMed

    Rasmussen, Susanne; Parsons, Anthony J; Xue, Hong; Liu, Qianhe; Jones, Christopher S; Ryan, Geraldine D; Newman, Jonathan A

    2014-04-15

    Lolium perenne cultivars with elevated levels of fructans in leaf blades (high sugar-content grasses) have been developed to improve animal nutrition and reduce adverse environmental impacts of pastoral agricultural systems. Expression of the high sugar trait can vary substantially depending on genotype×environment (G×E) interactions. We grew three potential high sugar-content and a control cultivar in three temperature regimes and quantified water soluble carbohydrates (WSCs) and the expression of all functionally characterised L. perenne fructan pathway genes in leaf tissues. We also analysed the distribution, expression and sequence variation of two specific isoforms of Lp6G-FFT (fructan: fructan 6G-fructosyltransferase). Our study confirmed a significant G×E interaction affecting the accumulation of fructans in the high sugar-content cultivar AberDart, which accumulated higher levels of high DP (degree of polymerisation) fructans in blades compared to the control cultivar only when grown at 20°C (day)/10°C (night) temperatures. The cultivar Expo on the other hand accumulated significantly higher levels of high DP fructans in blades independent of temperature. Fructan levels in pseudostems were higher than in blades, and they increased markedly with decreasing temperature, but there was no consistent effect of cultivar in this tissue. The expression of the high sugar trait was generally positively correlated with transcript levels of fructosyltransferases. Presence and expression of only one of the two known 6G-FFT isoforms was positively correlated with high fructan biosynthesis, while the second isoform was associated with low fructan concentrations and positively correlated with fructan exohydrolase gene expression. The presence of distinct 6G-FFT sequence variants appears to be associated with the capacity of high sugar-content grasses to accumulate higher fructan levels particularly at warmer temperatures. These findings might be exploited for the

  7. 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 ...

  8. 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...

  9. Tillage requirements for vegetables following winter annual grazing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Alabama, over 400,000 ac of winter annuals are grazed prior to planting summer row crops. Previous research indicates that cattle grazed on ryegrass (Lolium multiflorum L.) pastures over the winter months in Alabama can be profitable, but winter grazing creates excessive compaction, which advers...

  10. Effects of Wastewater and Sewage Sludge on the Growth and Chemical Composition of Turfgrass.

    DTIC Science & Technology

    1978-11-01

    of Kentucky bluegrass (Poa pratensis L. var. ’Merion’), red fescue ( Festuca rubra L. var. ’Pennlawn’) and annual ryegrass. The mixtures were grown in...turfgrass mixtures. A mixture of tall fescue ( Festuca arundinacea Scheb var. ’K-31’) and annual ryegrass (Lolium multiflorum Lam.) was compared to a mixture

  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. 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...

  13. 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...

  14. 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...

  15. 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] ...

  16. 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...

  17. 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…

  18. 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…

  19. Population Research.

    ERIC Educational Resources Information Center

    National Inst. of Child Health and Human Development (NIH), Bethesda, MD.

    The scope of population research as carried on by the National Institute of Child Health and Human Development (NICHD) is set forth in this booklet. Population problems of the world, United States, and the individual are considered along with international population policies based on voluntary family planning programs. NICHD goals for biological…

  20. Stabilizing population.

    PubMed

    Brown, L; Mitchell, J

    1998-04-01

    This article is a reprint of the Worldwatch Institute's "State of the World Report," Chapter 10: "Building a New Economy." 16 countries reached zero population growth by 1997. 33 countries have stabilized population, which amounts to 14% of world population. It is estimated that by 2050 population will include an additional 3.6 billion people beyond the present 6 billion. About 60% of the added population will be in Asia, an increase from 3.4 billion in 1995 to 5.4 billion in 2050. China's current population of 1.2 billion will reach 1.5 billion. India's population is expected to rapidly rise from 930 million to 1.53 billion. Populations in the Middle East and North Africa are expected to double in size. Sub-Saharan population is expected to triple in size. By 2050, Nigeria will have 339 million people, which was the entire population of Africa in 1960. There is a great need to stabilize population in a number of currently unstabilized countries. In 1971, Bangladesh and Pakistan had the same population; however, by 2050, Pakistan, without a strong commitment to reducing population growth, will have 70 million more people than Bangladesh. Population stabilization will depend on removal of physical and social barriers that prevent women from using family planning services and thereby help them control their own unwanted fertility. Stabilization will require poverty alleviation and removal of the need for large families. Family size is reduced with lower infant and child mortality risk, increased education, a higher legal age of marriage, and investment in stabilization programs. Solutions to global population growth cannot wait for health reform and budget deficit reductions.

  1. Mapping Drought QTL in Tall Fescue Populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tall fescue [Lolium arundinacetum (Schreb.) Darbysh.] growth and persistence are adversely affected by the hot-dry summers in the Southern Great Plains (Hopkins, 2005). Both forage yield and drought tolerance are difficult to select for because of large genotype-by-environment interactions. The ob...

  2. 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…

  3. A population geographer's population pyramid.

    PubMed

    Sternstein, L

    1989-07-01

    A population geographer cannot depend on the standard population profile because it does not reflect spatial distribution of the desired characteristics. A more revealing approach is the modified box-and- whisker plot with the vertical lines of the box placed at the 1st and 3rd quartiles and the whiskers defining the variance. The geography of the age-sex structure variability in Thailand was examined using this method and by mapping and classifying all the age-sex structures. Classification of these structures includes comparing adjacent age-sex group differences, determining population profiles at each significance level, and spatially portraying each population structure. If the profile includes a 10th or more of the districts, it is called a uniform population profile. One should not generalize over a wide grouping of data because data is not normally regular. Geographical mapping given a usable description of the findings only when appropriate subdivisions of the data are utilized.

  4. [Population education].

    PubMed

    Niang, M

    1992-12-01

    Africa has the highest population growth rate in the world (3%). It has 650 million people (about 900 million in 2000). Rapid population growth has serious consequences which, if not addressed, will be disastrous. This worrisome situation has led some governments to adopt demographic policies to slow down population growth. The UN Economic, Scientific and Cultural Organization (UNESCO) recommends that schools provide population education. Various population conferences have popularized population education in schools among African countries. UNESCO began its regional program on population education in Africa in 1969. National family life and population education (FL/PE) projects have increased from 4 in 1970 to 32 in 1990 (17 in French- and Portuguese-speaking Africa and 5 in English-speaking Africa). These projects teach students about the links between demographic problems and socioeconomic factors and contemporary culture. They aim for total development of the individual and improvement of the quality of life for the individual, family, and community. Topics covered in FL/PE are birth rate; fertility; health; and maternal, infant, and child mortality; unwanted pregnancy; illegal abortion; sexually transmitted diseases; rural-urban migration; and urbanization. Benin introduced FL/PE at all levels of its education system while Senegal, Guinea, Mauritania, and Zaire introduced it to only the primary and secondary school levels. Some countries teach FL/PE as one discipline while most countries (e.g., Senegal) have integrated it into other disciplines (e.g., geography). FL/PE should begin in primary schools because they have the most students and prepare students for middle schools, which provide FL/PE. Elementary education in Senegal is being overhauled to introduce current major problems bit by bit. Senegal also wants to incorporate FL/PE into literacy and adult education programs. Integration of FL/PE into other disciplines should be encouraged.

  5. T cell epitopes of the major fraction of rye grass Lolium perenne (Lol p I) defined using overlapping peptides in vitro and in vivo. I. Isoallergen clone1A.

    PubMed

    Bungy Poor Fard, G A; Latchman, Y; Rodda, S; Geysen, M; Roitt, I; Brostoff, J

    1993-10-01

    One hundred and fifteen overlapping synthetic peptides spanning the entire sequence of the iso-allergen clone1A of Lol p I from rye grass Lolium perenne were synthesized by the multi-pin technique. The peptides were overlapping 12mers, offset by two residues and overlapping by 10 residues. Sets of six adjacent overlapping peptides (except pool-1, 15, 20) were pooled and were used in vitro and in vivo to map the T cell epitopes on Lol p I. Six atopics who were skin test and RAST positive to rye grass showed T cell responses to L. perenne extract (LPE) and its major fraction (Lol p I). Five out of six showed T cell responses in vitro to peptide pool-17, while five non-atopics did not respond to any of the peptide pools. By testing the individual peptides of pool-17, we have located the T cell epitope on Lol p I. Interestingly, when we tested pool-17 and its single peptides in vivo by intradermal skin testing we found in one patient a typical DTH after 24-48 h to pool-17 and its peptides (peptides 3 and 4) which exactly matched the in vitro responses. By defining the T cell epitopes in this way a greater understanding of the allergic response to pollen will be obtained, and a more effective and less dangerous vaccine may be possible for treating patients with hay fever.

  6. Population growth.

    PubMed

    1984-01-01

    Despite efforts to reduce population growth, the World Bank projects a world population of 10 billion by 2050, with 7 billion living in developing countries. From October 1979 to September 1984, the US Agency for International Development (AID) funded the Research Triangle Institute's (RTI) Integrated Population and Development Planning (IPDP) project to assess rapid population growth effects in 25 developing countries. In October 1984, US AID extended funding for the program, nicknamed INPLAN, for 3 years, at a cost of $6.3 million. Up to 50% of people in developing countries are under age 15, a fact that guarantees large population increases for the next 50-75 years. Also, many regions have been slow to correlate high fertility with socioeconomic development, and in some areas, fertility is actually increasing. INPLAN aims to make governments more aware of population dynamics and to provide training and tools for effective development planning. 40% of INPLAN's work will be done in Africa, 25% in Latin America, and 20% in Asia, with some activity in the Near East. One project in Egypt, involving the use of model generation by microcomputer, was developed by RTI to show rural to urban migration and rapid population growth affects on the educational system. INPLAN expects to develop several other planning sector models on labor force and employment, health and family planning, food supply, housing, and urban development, and apply them to 20-25 countries. Another project provided 9 microcomputer systems and training to Nigerian government agencies. IMPLAN will purchase and distribute 60 such systems in the future.

  7. Population aging.

    PubMed

    1999-04-01

    This paper focuses on the impact of population aging in China, the most densely populated country in the world. Statistics indicate that by the end of 1998, 83.75 million out of the 1.248 billion Chinese people will be over 65 years old. According to the UN standards, China will soon become an aging society. The aging population poses several challenges to the country with the greatest challenge being the increasing social responsibility to care for the aged. With the undeveloped legislative framework to protect the interests of the aged and the serious drawbacks in the pension system to cater only to the income part and not the service part of the aged, China is not yet ready for the advent of aging. Violation of the rights of senior citizens is still very rampant despite enactment of the law on Protection of the Rights of the Elderly in 1996. Moreover, China is not economically ready to become an aging society. China faces this challenge by adopting a three-pronged approach to solve the problem namely: family support, establishment of nursing homes, and creating a social security framework that addresses the needs of the society suited to the Chinese condition. It is believed that with the growing economy of the country and the rising income of its people, a comprehensive social security net will be created to take care of the aged.

  8. Kampuchea: population.

    PubMed

    The United Nations High Commission for Refugees (UNHCR) recently reported that Kampuchea has an estimated population of 6 million. The count was made to determine future United Nations aid to Kampuchea. The count, made by administrators in Kampuchea's 19 provinces, reached a total of 6.4 million versus the 5.75 million estimated by the central government in Phnom Penh. The population estimate made by the Kampuchea provincial administrators surprised observers of the country, including UN representatives, in view of the country's decade of experience with war and destruction, which took a heavy toll on the population; the fatalities in the Vietnamese invasion of 1979, and the ensuing famine of that year. The 1979 vital statistics of Kampuchea are presented in Table 1. Kampuchean refugees at the Thai border camps were reported to be reluctant to go back to their country in spite of reports of good foodgrain harvests and improved prospects for living. The refugees' main concern was their fear and hate of both the Vietnamese troops and the Khmer Rouge.

  9. 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.

  10. 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

  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

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

    2011-03-01

    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.

  12. Molecular and functional characterization of a cDNA encoding fructan:fructan 6G-fructosyltransferase (6G-FFT)/fructan:fructan 1-fructosyltransferase (1-FFT) from perennial ryegrass (Lolium perenne L.).

    PubMed

    Lasseur, Bertrand; Lothier, Jérémy; Djoumad, Abdelmadjid; De Coninck, Barbara; Smeekens, Sjef; Van Laere, André; Morvan-Bertrand, Annette; Van den Ende, Wim; Prud'homme, Marie-Pascale

    2006-01-01

    Fructans are the main storage compound in Lolium perenne. To account for the prevailing neokestose-based fructan synthesis in this species, a cDNA library of L. perenne was screened by using the onion (Allium cepa) fructan:fructan 6G-fructosyltransferase (6G-FFT) as a probe. A full length Lp6G-FFT clone was isolated with significant homologies to vacuolar type fructosyltransferases and invertases. The functionality of the cDNA was tested by heterologous expression in Pichia pastoris. The recombinant protein demonstrated both 6G-FFT and fructan:fructan 1-fructosyltransferase activities (1-FFT) with a maximum 6G-FFT/1-FFT ratio of two. The activity of 6G-FFT was investigated with respect to developmental stage, tissue distribution, and alterations in carbohydrate status expression and compared to sucrose:sucrose 1-fructosyltransferase (1-SST). Lp6G-FFT and Lp1-SST were predominantly expressed in the basal part of elongating leaves and leaf sheaths. Expression of both genes declined along the leaf axis, in parallel with the spatial occurrence of fructan and fructosyltransferase activities. Surprisingly, Lp6G-FFT was highly expressed in photosynthetically active tissues where very low extractable fructosyltransferase activity and fructan amounts were detected, suggesting a post-transcriptional regulation of expression. Lp6G-FFT gene expression increased only in elongating leaves following similar increases of sucrose content in blades, sheaths, and elongating leaf bases. Regulation of Lp6G-FFT gene expression depends on the tissue according to its sink-source status.

  13. Exogenous Melatonin Suppresses Dark-Induced Leaf Senescence by Activating the Superoxide Dismutase-Catalase Antioxidant Pathway and Down-Regulating Chlorophyll Degradation in Excised Leaves of Perennial Ryegrass (Lolium perenne L.)

    PubMed Central

    Zhang, Jing; Li, Huibin; Xu, Bin; Li, Jing; Huang, Bingru

    2016-01-01

    Leaf senescence is a typical symptom in plants exposed to dark and may be regulated by plant growth regulators. The objective of this study was to determine whether exogenous application of melatonin (N-acetyl-5-methoxytryptamine) suppresses dark-induced leaf senescence and the effects of melatonin on reactive oxygen species (ROS) scavenging system and chlorophyll degradation pathway in perennial grass species. Mature perennial ryegrass (Lolium perenne L. cv. ‘Pinnacle’) leaves were excised and incubated in 3 mM 2-(N-morpholino) ethanesulfonic buffer (pH 5.8) supplemented with melatonin or water (control) and exposed to dark treatment for 8 days. Leaves treated with melatonin maintained significantly higher endogenous melatonin level, chlorophyll content, photochemical efficiency, and cell membrane stability expressed by lower electrolyte leakage and malondialdehyde (MDA) content compared to the control. Exogenous melatonin treatment also reduced the transcript level of chlorophyll degradation-associated genes and senescence marker genes (LpSAG12.1, Lph36, and Lpl69) during the dark treatment. The endogenous O2- production rate and H2O2 content were significantly lower in these excised leaves treated with melatonin compared to the water control. Exogenous melatonin treatment caused increases in enzymatic activity and transcript levels of superoxide dismutase and catalase but had no significant effects on ascorbate peroxidase, glutathione reductase, dehydroascorbate reductase, and monohydroascorbate reductase. The content of non-enzymatic antioxidants, such as ascorbate and dehydroascorbate, were decreased by melatonin treatment, while the content of glutathione and oxidized glutathione was not affected by melatonin. These results suggest that the suppression of dark-induced leaf senescence by exogenous melatonin may be associated with its roles in regulating ROS scavenging through activating the superoxide dismutase-catalase enzymatic antioxidant pathway and

  14. Differential composition of bacterial communities as influenced by phenanthrene and dibenzo[a,h]anthracene in the rhizosphere of ryegrass (Lolium perenne L.).

    PubMed

    Corgié, S C; Beguiristain, T; Leyval, C

    2006-12-01

    Bioremediation technologies of Polycyclic Aromatic Hydrocarbons (PAH) are often limited by the recalcitrance to biodegradation of high molecular weight (HMW) PAH. Rhizosphere is known to increase the biodegradation of PAH but little is known about the biodegradability of these HMW compounds by rhizosphere bacteria. This study compared the effects of a 3 and a 5-ring PAH, phenanthrene (PHE) and dibenzo[a,h]anthracene (dBA) respectively, on the composition of bacterial community, the bacterial density and the biodegradation activity. Compartmentalized devices were designed to harvest three consecutive sections of the rhizosphere. Rhizosphere and non-rhizosphere compartments were filled with PHE or dBA spiked or unspiked sand and inoculated with a soil bacterial inoculum. Different bacterial communities and degradation values were found 5 weeks after spiking with PHE (41-76% biodegradation) and dBA (12-51% biodegradation). In sections closer to the root surface, bacterial populations differed as a function of the distance to roots and the PAH added, whereas in further rhizosphere sections, communities were closer to those of the non-planted treatments. Biodegradation of PHE was also a function of the distance to roots, and decreased from 76 to 42% within 9 mm from the roots. However, biodegradation of dBA was significantly higher in the middle section (3-6 mm from roots) than the others. Rhizosphere degradation of PAH varies with the nature of the PAH, and C fluxes from roots could limit the degradation of dBA.

  15. 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.

  16. Population strategy.

    PubMed

    Kunii, C

    1989-12-01

    In this article, Chojiro Kunii, chairman and executive director of the Japanese Organization for International Cooperation in Family Planning (JOICFP), briefly describes the evolution of the INtegrated Family Planning, Nutrition, and Parasite Control Project (IP). The IP project began in Japan during the post-war period, when midwives and public health nurses introduced family planning alongside maternal and child health care services to make it more acceptable to people. Based on Japan's experience, JOICFP formed an international cooperation project based on parasite control, family planning, and nutrition. Introduced in several Asian countries in the mid-1970s, the project was quickly transported to Central and South America. And in 1983, Africa witnesses its first IP project. This took place in the Masama district of Tanzania, where the results of deworming quickly captures the attention of the population, making it easier for family planning workers to spread their message. In the 2 regions where the IP project was introduced, contraceptive prevalence among women has increased from 9.3% to 33%, and from 27% to 60%. Tanzania is now considering incorporating the IP project in its next 5-year development plan. Other African countries have followed suit. Kunii explains that JOICFP's Ip project enjoys support from both IPPF and UNFPA. He adds that, for its 2nd stage of development, the IP project hopes to become a union of family planning and preventive health. This new phase can already be observed in Asian countries. In developing its population strategy, JOICFP learned from the experience' of Japan, which demonstrated the importance of balancing quantity and quality.

  17. Population Genetics with Fluctuating Population Sizes

    NASA Astrophysics Data System (ADS)

    Chotibut, Thiparat; Nelson, David R.

    2017-02-01

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

  18. Does White Clover (Trifolium repens) Abundance in Temperate Pastures Determine Sitona obsoletus (Coleoptera: Curculionidae) Larval Populations?

    PubMed Central

    McNeill, Mark R.; van Koten, Chikako; Cave, Vanessa M.; Chapman, David; Hodgson, Hamish

    2016-01-01

    To determine if host plant abundance determined the size of clover root weevil (CRW) Sitona obsoletus larval populations, a study was conducted over 4 years in plots sown in ryegrass (Lolium perenne) (cv. Nui) sown at either 6 or 30 kg/ha and white clover (Trifolium repens) sown at a uniform rate of 8 kg/ha. This provided a range of % white clover content to investigate CRW population establishment and impacts on white clover survival. Larval sampling was carried out in spring (October) when larval densities are near their spring peak at Lincoln (Canterbury, New Zealand) with % clover measured in autumn (April) and spring (September) of each year. Overall, mean larval densities measured in spring 2012–2015 were 310, 38, 59, and 31 larvae m-2, respectively. There was a significant decline in larval populations between 2012 and 2013, but spring populations were relatively uniform thereafter. The mean % white clover measured in autumns of 2012 to 2015 was 17, 10, 3, and 11%, respectively. In comparison, mean spring % white clover from 2012 to 2015, averaged c. 5% each year. Analysis relating spring (October) larval populations to % white clover measured in each plot in autumn (April) found the 2012 larval population to be statistically significantly larger in the ryegrass 6 kg/ha plots than 30 kg/ha plots. Thereafter, sowing rate had no significant effect on larval populations. From 2013 to 2015, spring larval populations had a negative relationship with the previous autumn % white clover with the relationship highly significant for the 2014 data. When CRW larval populations in spring 2013 to 2015 were predicted from the 2013 to 2015 autumn % white clover, respectively, based on their positive relationship in 2012, the predicted densities were substantially larger than those observed. Conversely, when 2015 spring larval data and % clover was regressed against 2012–2014 larval populations, observed densities tended to be higher than predicted, but the numbers came

  19. Does White Clover (Trifolium repens) Abundance in Temperate Pastures Determine Sitona obsoletus (Coleoptera: Curculionidae) Larval Populations?

    PubMed

    McNeill, Mark R; van Koten, Chikako; Cave, Vanessa M; Chapman, David; Hodgson, Hamish

    2016-01-01

    To determine if host plant abundance determined the size of clover root weevil (CRW) Sitona obsoletus larval populations, a study was conducted over 4 years in plots sown in ryegrass (Lolium perenne) (cv. Nui) sown at either 6 or 30 kg/ha and white clover (Trifolium repens) sown at a uniform rate of 8 kg/ha. This provided a range of % white clover content to investigate CRW population establishment and impacts on white clover survival. Larval sampling was carried out in spring (October) when larval densities are near their spring peak at Lincoln (Canterbury, New Zealand) with % clover measured in autumn (April) and spring (September) of each year. Overall, mean larval densities measured in spring 2012-2015 were 310, 38, 59, and 31 larvae m(-2), respectively. There was a significant decline in larval populations between 2012 and 2013, but spring populations were relatively uniform thereafter. The mean % white clover measured in autumns of 2012 to 2015 was 17, 10, 3, and 11%, respectively. In comparison, mean spring % white clover from 2012 to 2015, averaged c. 5% each year. Analysis relating spring (October) larval populations to % white clover measured in each plot in autumn (April) found the 2012 larval population to be statistically significantly larger in the ryegrass 6 kg/ha plots than 30 kg/ha plots. Thereafter, sowing rate had no significant effect on larval populations. From 2013 to 2015, spring larval populations had a negative relationship with the previous autumn % white clover with the relationship highly significant for the 2014 data. When CRW larval populations in spring 2013 to 2015 were predicted from the 2013 to 2015 autumn % white clover, respectively, based on their positive relationship in 2012, the predicted densities were substantially larger than those observed. Conversely, when 2015 spring larval data and % clover was regressed against 2012-2014 larval populations, observed densities tended to be higher than predicted, but the numbers came

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

    PubMed Central

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

    2015-01-01

    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

  1. 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.

  2. Global Population Profile: 2002. International Population Reports

    ERIC Educational Resources Information Center

    Christenson, Matthew; McDevitt, Thomas; Stanecki, Karen

    2004-01-01

    Global Population Profile: 2002 summarizes the most important trends in global population at the dawn of the 21st century. The presentation is organized around four themes: (1) Global Population; (2) Growth, Global Population; (3) Composition, Contraceptive Prevalence in the Developing World; and (4) the AIDS Pandemic in the 21st Century. This…

  3. 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.

  4. 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

  5. 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.

  6. 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

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

    PubMed

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

    2015-07-01

    We applied a (15)N 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).

  8. 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...

  9. 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 ...

  10. 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 ...

  11. Natural enemies act faster than endophytic fungi in population control of cereal aphids.

    PubMed

    Härri, Simone A; Krauss, Jochen; Müller, Christine B

    2008-05-01

    1. Fast-growing populations of phytophagous insects can be limited by the presence of natural enemies and by alkaloids that are produced by symbiotic associations of many temperate grass species with endophytic fungi. It is unclear if and how acquired plant defences derived from endophytic fungi interact with natural enemies to affect phytophagous insect populations. 2. To assess the relative importance of endophytic fungi compared to that of natural enemies on the population dynamics of phytophagous insects, we carried out a fully factorial field experiment, in which the presence of natural enemies and the presence of endophytic fungi were manipulated simultaneously. Target colonies of aphids were monitored for 8 weeks starting from their natural appearance in the field to the end of the aphid season. 3. We show that on Lolium perenne increased natural enemy densities reduced the individual numbers of two common cereal aphids, Rhopalosiphum padi and Metopolophium festucae. 4. The presence of the endophytic fungi Neotyphodium lolii reduced the number of M. festucae but did not affect the number of R. padi. The reduction in R. padi numbers by predators and parasitoids was not influenced by the presence of endophytes. For adult M. festucae, however, the negative effects of natural enemies were significant only in the absence of endophytes. 5. Over the duration of the experiment, the effect of natural enemies on aphid colony growth was much stronger than the effect of the endophytic fungi N. lolii, presumably because predator and parasitoid action on aphid colonies is much faster than any effects of endophytes. 6. Our results demonstrate that with simultaneous action of acquired endosymbionts and natural enemies, both factors can control aphid colony growth but they generally act independently of each other.

  12. 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.

  13. 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)

  14. 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)

  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. 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...

  17. 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…

  18. 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.

  19. Inherited fungal symbionts enhance establishment of an invasive annual grass across successional habitats.

    PubMed

    Uchitel, Andrea; Omacini, Marina; Chaneton, Enrique J

    2011-02-01

    Plants infected with vertically transmitted fungal endophytes carry their microbial symbionts with them during dispersal into new areas. Yet, whether seed-borne endophytes enhance the host plant's ability to overcome colonisation barriers and to regenerate within invaded sites remains poorly understood. We examined how symbiosis with asexual endophytic fungi (Neotyphodium) affected establishment and seed loss to predators in the invasive annual grass Lolium multiflorum (Italian ryegrass) across contrasting successional plots. Italian ryegrass seeds with high and low endophyte incidence were sown into three communities: a 1-year-old fallow field, a 15-year-old grassland, and a 24-year-old forest, which conformed to an old-field chronosequence in the eastern Inland Pampa, Argentina. We found that endophyte infection consistently increased host population recruitment and reproductive output. Endophyte presence also enhanced aerial biomass production of ryegrass in a low recruitment year but not in a high recruitment year, suggesting that symbiotic effects on growth performance are density dependent. Endophyte presence reduced seed removal by rodents, although differential predation may not account for the increased success of infected grass populations. Overall, there was no statistical evidence for an endophyte-by-site interaction, indicating that the fungal endosymbiont benefitted host establishment regardless of large differences in biotic and abiotic environment among communities. Our results imply that hereditary endophytes may increase the chances for host grass species to pass various ecological filters associated with invasion resistance across a broad range of successional habitats.

  20. Cross-resistance profile of mesosulfuron-methyl-resistant Italian ryegrass in the southern United States.

    PubMed

    Kuk, Yong In; Bugos, Nilda R

    2007-04-01

    Diclofop-resistant Lolium species (ryegrass) is a major weed problem in wheat production worldwide. This study was conducted to determine the resistance pattern of diclofop-resistant ryegrass accessions from the southern United States to mesosulfuron-methyl, a recently commercialized herbicide for ryegrass control in wheat; to determine the cross-resistance pattern of a Lolium multiflorum Lam. (Italian ryegrass) accession, 03-1, to acetolactate synthase (ALS) and acetyl-CoA carboxylase (ACCase) inhibitors; and to determine the resistance mechanism of Italian ryegrass to mesosulfuron-methyl. Seventeen ryegrass accessions from Arkansas and Louisiana, including standard resistant and susceptible accessions, were used in this experiment. Fourteen of the 17 accessions were more resistant (four- to > 308-fold) to diclofop than the standard susceptible biotype. One accession, 03-1, was resistant to mesosulfuron-methyl as well as to other ALS inhibitor herbicides such as chlorsulfuron, imazamox and sulfometuron. Accession 03-1, however, did not show multiple resistance to the ACCase inhibitor herbicides diclofop, fluazifop, clethodim, sethoxydim and pinoxaden, nor to glyphosate. The in vivo ALS activity of the 03-1 biotype was less affected by mesosulfuron-methyl than the susceptible biotype. This indicates that the resistance mechanism of Italian ryegrass to mesosulfuron-methyl is partly due to an alteration in the target enzyme, ALS. It is concluded that diclofop-resistant ryegrass in the southern United States can be generally controlled by mesosulfuron-methyl. However, mesosulfuron-methyl must be used with caution because not all ryegrass populations are susceptible to it. There is a need for more thorough profiling of ryegrass resistance to herbicides.

  1. 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…

  2. 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 ...

  3. The Growing Human Population.

    ERIC Educational Resources Information Center

    Keyfitz, Nathan

    1989-01-01

    Discusses the issue of human population. Illustrates the projections of the growing human population in terms of developed and less developed countries. Describes the family planning programs in several countries. Lists three references for further reading. (YP)

  4. 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…

  5. 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…

  6. 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.

  7. 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…

  8. 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…

  9. 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…

  10. 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.…

  11. 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.

  12. Nutrients can enhance the abundance and expression of alkane hydroxylase CYP153 gene in the rhizosphere of ryegrass planted in hydrocarbon-polluted soil.

    PubMed

    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.

  13. The Effect of Marigolds (Tagetes spp.) and Other Cover Crops on Pratylenchus penetrans and on Following Potato Crops

    PubMed Central

    Kimpinski, J.; Arsenault, W. J.; Gallant, C. E.; Sanderson, J. B.

    2000-01-01

    Root-lesion nematodes (primarily Pratylenchus penetrans) were monitored in two marigold cultivars (Tagetes tenuifolia cv. Nemakill and cv. Nemanon), annual ryegrass (Lolium multiflorum cv. Lemtal), red clover (Trifolium pratense cv. Florex), and soybean (Glycine max cv. Proteus), and in the following potato (Solanum tuberosum cv. Superior) crop during three growth sequences. Meadow fescue (Festuca elatior cv. Miner) and bee plant (Phacelia tanacetifolia cv. Gipha) were added to the trial in the second year. Black-eyed Susan (Rudbeckia hirta, unidentified cv.) and two additional marigold cultivars (T. patula ssp. nana, unidentified cv., and T. erecta cv. Crackerjack) were included in the final sequence. Population levels of root-lesion nematodes were consistently lower under marigolds compared to the other cover crops tested. Correspondingly, average potato tuber yields were significantly higher (8-14%) when potato followed marigolds. The highest levels of root-lesion nematodes occurred under red clover and soybean, and the average potato tuber yields were lowest following these crops. PMID:19271006

  14. 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

  15. Population 101. A primer.

    PubMed

    Gelbard, A

    1997-09-01

    This article summarizes basic statistics on population growth, concepts about population momentum, and evidence of fertility declines in the world. World population was about 5.84 billion in mid-1997. 86 million people are added yearly. Almost 1 billion people are added every 11 years. The first billion was reached in the early 1800s, and each billion took fewer and fewer years to attain. World population is expected to expand until about 2050 and level off after 2150. Dramatic declines in death rates and health improvements contributed to smaller numbers of children per woman. Absolute increases are due to population momentum, which is the continued large concentration of women in the childbearing years. World population will continue to grow, even after replacement-level fertility of 2 children/woman is reached, due to population momentum. Developing countries continue to have a young age structure and high birth rates, which result in higher population growth. 35% of population in developing countries is aged under 15 years, and almost 50% of population in sub-Saharan African countries is aged under 15 years. Fertility has declined in most regions, with the exception of sub-Saharan Africa. All developing regions have above replacement-level fertility. Declines to below replacement-level fertility in developed countries is attributed to improvements in health for women and children, greater use of family planning, and more education for women and girls. Fertility is high where infant mortality is high. Family planning allows mothers to have healthier children.

  16. Molecular Population Genetics

    PubMed Central

    Casillas, Sònia; Barbadilla, Antonio

    2017-01-01

    Molecular population genetics aims to explain genetic variation and molecular evolution from population genetics principles. The field was born 50 years ago with the first measures of genetic variation in allozyme loci, continued with the nucleotide sequencing era, and is currently in the era of population genomics. During this period, molecular population genetics has been revolutionized by progress in data acquisition and theoretical developments. The conceptual elegance of the neutral theory of molecular evolution or the footprint carved by natural selection on the patterns of genetic variation are two examples of the vast number of inspiring findings of population genetics research. Since the inception of the field, Drosophila has been the prominent model species: molecular variation in populations was first described in Drosophila and most of the population genetics hypotheses were tested in Drosophila species. In this review, we describe the main concepts, methods, and landmarks of molecular population genetics, using the Drosophila model as a reference. We describe the different genetic data sets made available by advances in molecular technologies, and the theoretical developments fostered by these data. Finally, we review the results and new insights provided by the population genomics approach, and conclude by enumerating challenges and new lines of inquiry posed by increasingly large population scale sequence data. PMID:28270526

  17. Molecular Population Genetics.

    PubMed

    Casillas, Sònia; Barbadilla, Antonio

    2017-03-01

    Molecular population genetics aims to explain genetic variation and molecular evolution from population genetics principles. The field was born 50 years ago with the first measures of genetic variation in allozyme loci, continued with the nucleotide sequencing era, and is currently in the era of population genomics. During this period, molecular population genetics has been revolutionized by progress in data acquisition and theoretical developments. The conceptual elegance of the neutral theory of molecular evolution or the footprint carved by natural selection on the patterns of genetic variation are two examples of the vast number of inspiring findings of population genetics research. Since the inception of the field, Drosophila has been the prominent model species: molecular variation in populations was first described in Drosophila and most of the population genetics hypotheses were tested in Drosophila species. In this review, we describe the main concepts, methods, and landmarks of molecular population genetics, using the Drosophila model as a reference. We describe the different genetic data sets made available by advances in molecular technologies, and the theoretical developments fostered by these data. Finally, we review the results and new insights provided by the population genomics approach, and conclude by enumerating challenges and new lines of inquiry posed by increasingly large population scale sequence data.

  18. 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

  19. [Population and development].

    PubMed

    Castanon Romo, R; Sandoval Navarrete, J

    1996-01-01

    This broad survey of the debate concerning the relationship between population growth and economic development discusses the history and current status of world population growth, summarizes several influential theoretical positions on the topic, and proposes that redefinition of women's social role is indispensable if worldwide control of population growth is to be achieved. The introductory section discusses the acceleration of population growth in the second half of the 20th century and the increasing concentration of growth in the poor and developing countries. The positions of those who see in population control a means of promoting economic development and political stability are contrasted to the positions of those who believe that a large and growing population is the key to achieving economic and political progress. The international community, facing great uncertainty about the size, distribution, and well-being of the future world population, is increasingly concerned about the effect of growing numbers on the environment and natural resources. The second section summarizes the works of Malthus, Julian Simon, and the Club of Rome, and analyzes the propositions of demographic transition theory. The conclusion notes that despite uncertainty about the future of world population, development, and health, most of the poorest countries have become aware of the desirability of slowing population growth. A broad redefinition of the social role of women will inevitably accompany the worldwide demographic transition.

  20. Hypertension in special populations.

    PubMed

    Nesbitt, Shawna D

    2005-07-01

    Hypertension is a multifaceted disease that may present somewhat differently in various populations. It is clear that hypertensive treatment reduces cardiovascular, renal, and cerebrovascular outcomes for all patients, yet recent clinical trial data suggest that some groups may benefit more than others from specific drug intervention. Furthermore, these data justify specific approaches for some special populations. This article reviews important features of the presentation, rationale for treatment, and treatment recommendations for the treatment of hypertension in special populations. The special populations addressed include diabetic patients, the elderly, and women.

  1. 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...

  2. 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…

  3. 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)

  4. 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…

  5. Why Teach Population Education?

    ERIC Educational Resources Information Center

    Cook-Fuller, Charlotte; And Others

    Population education can help students develop coping skills and make responsible decisions as members of a family, a community, a nation, and a world. For example, by studying and understanding the impact of changes in population growth rates, compositional characteristics, and migration shifts, students, as future citizens, will be better able…

  6. Understanding Population Projections.

    ERIC Educational Resources Information Center

    Haub, Carl

    1987-01-01

    Population projections are "what if" computational exercises. Given selected assumptions about future trends in fertility, mortality, and migration, population trends can be projected. Government and business planners need this information, and they also require enough time to put facilities in place to meet future needs. Everyone benefits from a…

  7. Ecology and Population

    ERIC Educational Resources Information Center

    Hawley, Amos H.

    1973-01-01

    Author suggests that study of population growth is not a field of study only for ecologists. Population growth is related with social sciences in the nature of its process and future consequences. Broader, comprehensive approaches to this problem will be useful. (PS)

  8. Population Education Country Programmes.

    ERIC Educational Resources Information Center

    Population Education in Asia and the Pacific Newsletter, 1983

    1983-01-01

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

  9. 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…

  10. Why Population Matters, 1996.

    ERIC Educational Resources Information Center

    Population Action International, Washington, DC.

    Population growth around the world affects Americans through its impact on economy, environment, safety, and health, and the condition of the world children will inherit. The cumulative evidence is strong that current rates of population growth pose significant and interacting risks to human well-being and are a legitimate concern for Americans.…

  11. The World Population Dilemma.

    ERIC Educational Resources Information Center

    Population Reference Bureau, Inc., Washington, DC.

    This book is the third in a series published by the Population Reference Bureau aimed at illuminating the facts and consequences of human population dynamics for secondary and college-age students. Many illustrations, charts and graphs are included in this volume to help the reader grasp a number of the current ideas and concepts that are used in…

  12. 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…

  13. 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…

  14. 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…

  15. 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.

  16. 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.

  17. Population post-Rio.

    PubMed

    Myers, N

    1993-01-01

    The June 1993 Rio Earth Summit barely recognized population growth as an issue, despite the evidence that rapid population growth is harming both the environment and development efforts. One reason given for brushing the population issue to the sidelines was that the UN had a major population conference scheduled for 1994. This overlooked the fact that in the interim between the two conferences, the population problem would be compounded by an additional 200 million people. Any delay now will increase the number of potential parents in the future and create an ever-increasing problem. The male participants at Rio who were willing to procrastinate on population issues were joined by feminists who claimed that men should leave this issue to women. These women ignore the fact that men need to be more, not less, involved in family planning. Women need support in increasing their status and in improving educational opportunities for girls. Providing girls with as much education as boys receive in low-income nations would cost less than a quarter of a percent of the collective gross national product of these nations, and this education would provide a solid boast to their economies and to their family planning campaigns. Procrastinators on population issues must stop acting as though a spare planet is available when we overload the earth.

  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. [African population in history].

    PubMed

    Yang, S

    1984-11-29

    The growth rate of the African population has been fluctuating throughout history, affected by political, social, and economic events. 6000 years ago, the majority of the population was based in North Africa, because farming had been developed there. However, between the 11th and the 16th centuries, there was a constant decline in the population of that region, due to invasions from Europe and the black plague. During the same period, the population in the area south of the Sahara grew rapidly, as people there had gone into the iron tool period and farming had been developed. From the 16th to the mid-17th Century, population growth was considerable in Africa; more people had learned the technology of irrigation, corn and potatoes had been introduced from South America, and colonialism was not yet an issue. From the mid-17th to the mid-19th Century, there was no growth, due to the slave trade and wars between tribes. One estimate sets the direct and indirect loss during this period, as a result of the slave trade, at 100 million people. From the 1850s to the end of World War I, population growth started up again, chiefly influenced by the fact that the slave trade had essentially come to a half and modern medical care had become available on the continent. However, in central Africa, the region which suffered the worst blow from the slave trade, growth was very slow, while in East Africa the population was declining because of wars between colonists and natives, as well as natural disasters. Increases in population during this period were a result of immigration from Europe and India. From the end of World War I to the present, growth has been rapid, given improvements in medical services and standards of living, while most of the former colonies became independent after the 1950s. Consequently, almost all African countries are under great pressure now with regard to their populations.

  20. [Trends in population aging].

    PubMed

    Valkovics, E

    1990-11-01

    The age structure of the world population between 1950 and 1985 is analyzed according to changes in fertility, mortality, and international migration in developing and developed countries. "Relying on the results of the medium scenario of the population forecasts prepared by the U.N. Division of International Economic and Social Affairs, the author demonstrates that aging of the world population will become a global phenomenon, characteristic of every region and county of the world, between 1985 and 2025." (SUMMARY IN ENG AND RUS)

  1. Modeling Honey Bee Populations.

    PubMed

    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.

  2. Population approaches in paediatrics.

    PubMed

    Chatelut, Etienne

    2008-12-01

    Population pharmacokinetic (PK) approach is now often used to evaluate PK characteristics of a new compound during its clinical development. Recently, new legislation governing the development and authorization of medicines for use in children aged 0-17 years was introduced in the European Union. Among the strategies proposed in relation to clinical aspects, use of population PKs is stated. In this manuscript, comparison between standard PK and population PK methods will be briefly addressed to understand why the second is particularly adapted to perform PK studies in paediatrics. Then, specific patients' characteristics (covariates) in paediatrics will be presented. Examples of PK and PK-pharmacodynamic (PK-PD) studies will be finally given. The number of population PK studies published still exceeds largely those of PK-PD.

  3. 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.

  4. 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...

  5. 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)

  6. Evolving sparse stellar populations

    NASA Astrophysics Data System (ADS)

    Bruzual, Gustavo; Gladis Magris, C.; Hernández-Pérez, Fabiola

    2017-03-01

    We examine the role that stochastic fluctuations in the IMF and in the number of interacting binaries have on the spectro-photometric properties of sparse stellar populations as a function of age and metallicity.

  7. 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

  8. Population distribution policies.

    PubMed

    Richardson, H W

    1983-01-01

    Population distribution policies have received increasing attention in recent years, especially in developing countries. One reason is that, especially in heavily primate developing countries, the spacial distribution of population (and economic activity) has generated conditions that conflict with important societal goals, such as interpersonal and interregional equity, national security, political stability, improvement in the quality of life, optimal resource exploitation, and long-term economic efficiency. Moreover, in many cases, the overall development strategy as reflected in macro and sectoral policies, has strong implicit spatial impacts that have, more often than not, reinforced an "unfavorable" population distribution, that is, one that conflicts with national goals and priorities. The only way to correct that is to modify the overall development strategy or to implement offsetting explicit population distribution policies. Many countries have adopted population distribution policies in recent years, but they have varied greatly in degree of implementation. Clear failures have been very common, and there have been almost no undiluted successes. This indifferent success should not be used as an argument against planned population distribution. The present article provides an overview of population distribution policies with special but not total reference to developing countries. Population goals are analyzed and the argument that rural-metropolitan migration is excessive is critically discussed. Policy instruments to influence the location of both households and firms are evaluated. It is argued that strategies to control primate city growth, to promote small towns and secondary cities and to implement rural-development programs are complementary rather than alternatives. Partial strategies, such as relocation of the national capital, countermagnets, new towns, border region policies and land colonization schemes, should be adopted only in rare cases

  9. Population Density Modeling Tool

    DTIC Science & Technology

    2014-02-05

    of fatalities per loss. (2) where: POCA = Probability of Casualty (fatalities per loss) LCA = Lethal Crash Area of Aircraft (square...miles) Population Density = The average population density within the Potential Crash Area (PCA) (people per square miles) The LCA ...component in equation 2 has been previously calculated in the 3PRAT. The methodology used to determine the LCA is outlined in the report: Crash Lethality

  10. Can population grow forever?

    NASA Astrophysics Data System (ADS)

    Birch, P.

    1985-03-01

    Some theoretical calculations of the capacity of the universe to absorb an indefinitely increasing population of human beings are presented. It is proposed that by means of interstellar migration, the population, knowledge, and energy consumption of humans could increase forever. It is shown that although an open universe does not succumb to 'heat-death', the decay of very distant matter before mankind can reach it may present a problem.

  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.

  12. 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.

  13. Ambient has become strained. Identification of Acacia dealbata Link volatiles interfering with germination and early growth of native species.

    PubMed

    Souza-Alonso, Pablo; González, Luís; Cavaleiro, Carlos

    2014-09-01

    Acacia dealbata Link is a widespread invader in Mediterranean type ecosystems, and traits promoting its invasiveness are currently under investigation. Due to the dense atmosphere below its canopy, we hypothesized that volatile organic compounds (VOCs) released from flowers, leaves, litter, or a mixture of treatments exert inhibitory effects on the natives Trifolium subterraneum, Lolium multiflorum, Medicago sativa, and also on its own seeds. We reported that VOCs from flowers significantly reduced germination in L. multiflorum and A. dealbata; moreover, root length, stem length, aboveground and belowground biomass were also reduced in all species studied. Volatile organic compounds from flowers and the mixture also increased significantly malondialdehyde content in T. subterraneum and L. multiflorum. The effects of VOCs on antioxidant enzymatic activities were species dependent. Flowers enhanced peroxidase but decreased superoxide dismutase activity in T. subterraneum. In contrast, VOCs released from leaves increased the activity of superoxide dismutase in L. multiflorum. GC/MS analyses revealed 27 VOCs in the volatile fraction from flowers, 12 of which were exclusive to this fraction. Within them, heptadecadiene, n-nonadecane, n-tricosane, and octadecene represent 62% of the fraction. We present evidence that the VOCs released from A. dealbata flowers strongly inhibited germination and seedling growth of selected species, and mainly on its own seedlings. As far as we know, this is the first evidence of phytotoxicity induced by VOCs in invasive species belonging to the Acacia genus.

  14. A study of the human immune response to Lolium perenne (rye) pollen and its components, Lol p I and Lol p II (Rye I and Rye II). II. Longitudinal variation of antibody levels in relation to symptomatology and pollen exposure and correction of seasonally elevated antibody levels to basal values.

    PubMed

    Freidhoff, L R; Ehrlich-Kautzky, E; Meyers, D A; Marsh, D G

    1987-11-01

    This study used a standardized, dialyzed, Lolium perenne (ryegrass) pollen extract and two of its well-characterized components, Lol p I (Rye I) and Lol p II (Rye II), to characterize the longitudinal variation of both IgE and IgG antibody (Ab) levels, as well as total serum IgE levels, in 20 grass-allergic subjects followed for 13 months. Ab levels declined toward a basal level just before, and increased just after, the grass-pollination season, returning to the same basal level just before the next grass-pollination season. The least complex allergen, Lol II, demonstrated the most uniform pattern of variation in both IgE and IgG Ab levels. Total serum IgE levels demonstrated the least regular pattern of variation. Grass-pollen counts were strongly correlated with symptom-medication scores for these subjects (rs = 0.87). Initial values were correlated with the rise in total IgE and IgE Ab to Lol II across the grass-pollen season. Skin test results were correlated with initial IgE Ab levels for L. perenne pollen extract and Lol II. Finally, a procedure for correcting IgE Ab levels to basal values was proposed and tested. The correction procedure, for each IgE Ab, was based on the average rise during the grass-pollination season (or average decline after the grass-pollination season) observed for all subjects with that IgE Ab.

  15. World population perspectives 1985.

    PubMed

    Loraine, J A

    1985-01-01

    Some progress has been made in curbing global population growth, yet much remains to be done, particularly in 3rd world countries. Population growth reached its zenith between 1950-70. The growth rate then remained at 2% per annum. By the early 1970s, the pace began to slow, and by 1985 it was down to 1.7%. UN sources anticipate a further drop to 1.5% by 2000. The decline has been due primarily to falling birthrates in some developing nations. China with its 1-child policy has been responsible for a major effect, but also there have been notable declines in other Asian and in Latin American countries. One important factor is the inherent dynamic of the population process. The momentum of population growth is remarkable; world numbers are destined to increase for decade upon decade. Fertility levels and overall rates of population growth will determine when different regions of the world are likely to realize stability . Regarding the level at which the world population will stabilize eventually, the figures most commonly quoted by international agencies range from 8000-10,000 million. This total would strain the earth's carrying capacity to an unacceptable degree and produce ecological malpraxis. In 1985 the developed nations accounted for about 1/4 of the world's population. The rate of growth had been slow for over 20 years and currently is 0.6% per annum. The 2 major demographic changes in the area are continuing low birthrates and a marked rise in the relative and absolute numbers of elderly people. In 1985 the less developed world of Africa, Asia, and Latin America housed 3700 million people, about 3/4 of the world's total. During the next 15 years, 85% of the births are expected to occur in the less developed world. Developing countries show great variations with respect to such demographic indices as birthrates, death rates, and infant mortality rates, but they share with developed nations the marked increase in their numbers of old people. This trend is

  16. Population pressure rising.

    PubMed

    1994-08-01

    Even though the ESCAP region has been successful in slowing population growth, Asia will account for half of the global population increase every year, or about 1 billion persons in the next quarter century, according to a new report by the Asian Development Bank (ADB). That report, entitled "Population Policy Paper," states that Asia will be the global center of population aging largely because of big increases in the number of persons over the age of 65 in China, Japan and the region's newly industrializing economies. "By the year 2000, 86% of the world's aged will be in the Asia-Pacific region and by the year 2025 there are projected to be 687 million persons over the age of 65 in the region, placing unprecedented strains on economic and social systems far beyond what traditional extended family networks can absorb," the paper says. But the report also considers other aspects of overall population increase. "The prospect of an additional billion or so people in Asia over the next 25 years is daunting, since the implications for poverty, economic growth, unemployment and environmental quality are immense," it adds. The region's economies will have to scramble to generate jobs and livelihoods for tens of millions of young people for the next several decades. Rural-to-urban migration trends threaten the collapse of urban infrastructure, with the social tensions and political instability that such troubles bring, the report states.

  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.

  18. 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.

  19. 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.

  20. 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…

  1. World Population: Facts in Focus. World Population Data Sheet Workbook. Population Learning Series.

    ERIC Educational Resources Information Center

    Crews, Kimberly A.

    This workbook teaches population analysis using world population statistics. To complete the four student activity sheets, the students refer to the included "1988 World Population Data Sheet" which lists nations' statistical data that includes population totals, projected population, birth and death rates, fertility levels, and the…

  2. Relics: penguin population programs.

    PubMed

    Sun, L; Xie, Z

    2001-01-01

    What has been responsible for the increase in Chinstrap penguin populations during the past 40 years in maritime Antarctica? One view ascribes it to an increase in availability of their prey brought on by the decrease in baleen whale stocks. The contrary opinion, attributes it to environmental warming. This causes a gradual decrease in the frequency of cold years with extensive winter sea ice cover. A number of penguin monitoring programs are in progress and are expected to provide some answers to these questions. Unfortunately, it is not easy to distinguish natural variability from anthropogenic change since penguins are easily accessible predators of krill and the feeding range of the penguins has almost overlapped with the krill fishery in time and space in the last four decades. Therefore it is important to reconstruct the change of ancient penguin abundance and distribution in the absence of human activity. Many efforts have focused on surveying the abandoned penguin rookeries, but this method has not been able to give a continuous historical record of penguin populations. In several recent studies, ancient penguin excreta was scooped from the penguin relics in the sediments of the lake on penguin rookery, Ardley Island, maritime Antarctica. In these studies, penguin droppings or guano soil deposited in the lake and changes in sediment geochemistry have been used to calculate penguin population changes based upon the geochemical composition of the sediment core. The results suggest that climate change has a significant impact on penguin populations.

  3. 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…

  4. 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…

  5. Population: fiction and fact.

    PubMed

    1979-09-01

    This article was written to refute some common misunderstandings regarding worldwide population levels and worldwide nutrition levels. The world food supply is able to keep pace with high population growth levels. Worl food production currently meets world need; the problem is a distribution system which allocates food only to those who can pay rather than to those who need it. In many developing countries, the best agricultural lands are reserved for commercial crops rather than for subsistence crops. The U.S. food aid program does not help the most needy nations generally. The rate of world population growth is already slowing down. The desire for large families in developing countries is very often a realistic reaction to the prevailing economic system. Family planning programs will succeed. They will succeed even better in countries where general development planning is undertaken concurrently with family planning. Environmental problems are attributable to the consumption explosion in the rich countries rather than to the population explosion in the poor countries.

  6. Adam Smith on population.

    PubMed

    Spengler, J J

    1970-11-01

    Abstract Adam Smith dealt with questions of population mainly in his Wealth of Nations. His discussion falls roughly under five heads and reflects in considerable measure his image of the English economy. (1) A country's population capacity, given the average level of consumption, was conditioned by the stock of land, the skill with which it was cultivated, and the degree to which division of labour could be increased and thereby augment output for domestic use and sale in external markets. (2) Growth of population was essentially in response to growth of the demand for labour and served to increase division of labour. (3) The social mechanisms underlying elevation of the scale of living are touched upon, and in an optimistic spirit. (4) The distribution of a country's population responded to its progress in opulence, with the rate of this progress conditioned by the degree to which inappropriate (e.g. mercantilist) policies were avoided. (5) Smith dealt briefly with such matters as colonies, education, size of economy, environmental influences, and public policy, all of which he recognized as significant for the quantity and quality of a country's numbers.

  7. 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…

  8. Reconstructing Druze population history

    PubMed Central

    Marshall, Scarlett; Das, Ranajit; Pirooznia, Mehdi; Elhaik, Eran

    2016-01-01

    The Druze are an aggregate of communities in the Levant and Near East living almost exclusively in the mountains of Syria, Lebanon and Israel whose ~1000 year old religion formally opposes mixed marriages and conversions. Despite increasing interest in genetics of the population structure of the Druze, their population history remains unknown. We investigated the genetic relationships between Israeli Druze and both modern and ancient populations. We evaluated our findings in light of three hypotheses purporting to explain Druze history that posit Arabian, Persian or mixed Near Eastern-Levantine roots. The biogeographical analysis localised proto-Druze to the mountainous regions of southeastern Turkey, northern Iraq and southeast Syria and their descendants clustered along a trajectory between these two regions. The mixed Near Eastern–Middle Eastern localisation of the Druze, shown using both modern and ancient DNA data, is distinct from that of neighbouring Syrians, Palestinians and most of the Lebanese, who exhibit a high affinity to the Levant. Druze biogeographic affinity, migration patterns, time of emergence and genetic similarity to Near Eastern populations are highly suggestive of Armenian-Turkish ancestries for the proto-Druze. PMID:27848937

  9. 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)

  10. [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.

  11. Population and women's health.

    PubMed

    Abernethy, V

    1994-01-01

    Explanations of cultural patterns can be found in the economic context (carrying capacity) in which they develop. Population pressure explains the abuse of women throughout history and in modern times because overpopulation leads to devaluation of women's reproductive capacity. A cultural response to overpopulation includes practices that limit the numbers of women of reproductive age. Such practices foster son preference, which results in selective abortion, female infanticide, neglect and overwork of girls, dowry deaths, and discrimination against widows. The results of these practices are manifest in sex ratios that are culturally rather than naturally controlled and in demographic facts such as the calculation that 60 million females are missing in Asia alone (and perhaps more than 100 million worldwide). Women are also removed from a reproductive setting by being kidnapped or sold into prostitution or by being forced to adopt prostitution for economic survival. In cases where survival is threatened by environmental degradation and population growth, the most harsh cultural practices will emerge to adapt the population to the resources at hand. This situation creates an ethical dilemma posed by the problem of imposing Western values on a culture that is undertaking adaptive practices to insure its very survival. Ways to help women in these situation include limiting population growth humanely through family planning, provision of paid work to women, and creation of an environment that supports a small family ideal. Prosperity itself, through modernization, sometimes causes family sizes to increase. The most important intervention appears to be the provision of paid employment outside the home for women. On the other hand, large-scale wealth transfers and liberal immigration policies simply send signals that population pressure is a regional problem that can be alleviated by the international community. Increasing immigration to developed countries will place

  12. The population problem?

    PubMed

    Mcelroy, W

    1968-01-01

    Most governments that have considered the population problem have been doing a part time job, working to stabilize the population by spreading knowledge of oral contraception (OC) and other contraceptive devices. An inadequate job is being done in promoting the reduction of the birthrate. What is needed is an all out effort from all countries concerned. It was only in 1965 that a President of the US for the 1st time made a positive statement about the government's position and support for family planning programs. Until then all government agencies were careful to avoid discussing this matter in opening meetings. Thereafter, President Johnson repeatedly indicated that he recognized the seriousness of the problem and the need for intelligent and direct action. Yet, the appropriation and distribution of funds for population control in the US and developing countries has failed to keep pace with the superlative statements made by national and responsible individuals on the importance of the problem. Family planning is more than a program just for the distribution of contraceptive devices. Where knowledgeable personnel are available, they try to identify the broad social problems resulting from large familles. They try to influence the behavior of the individual couples with regard to family size. Yet, even in the US the number of personnel is inadequate to carry out this large educational program. The Committee on Population of the National Academy of Sciences stressed several points: a zero rate of population growth may prove essential in the long run but as a goal within the time horizon of present policy it has little support in either the developed or developing countries, certainly not among governments; a need exists for exploration of a broader range of measures for their potential contribution to the easing of population pressures, particularly in the developing countries where rapid population growth is particularly threatening; programs of social change need

  13. Secondary Globular Cluster populations

    NASA Astrophysics Data System (ADS)

    Fritze-v. Alvensleben, U.

    2004-02-01

    This study is motivated by two facts: 1. The formation of populous star cluster systems is widely observed to accompany violent star formation episodes in gas-rich galaxies as e.g. those triggered by strong interactions or merging. 2. The Globular Cluster (GC) systems of most but not all early-type galaxies show bimodal optical color distributions with fairly universal blue peaks and somewhat variable red peak colors, yet their Luminosity Functions (LFs) look like simple Gaussians with apparently universal turn-over magnitudes that are used for distance measurements and the determination of Ho. Based on a new set of evolutionary synthesis models for Simple (= single burst) Stellar Populations (SSPs) of various metallicities using the latest Padova isochrones I study the color and luminosity evolution of GC populations over the wavelength range from U through K, providing an extensive grid of models for comparison with observations. I assume the intrinsic widths of the color distributions and LFs to be constant in time at the values observed today for the Milky Way or M 31 halo GC populations. Taking the color distributions and LFs of the Milky Way or M 31 halo GC population as a reference for old metal-poor GC populations in general, I study for which combinations of age and metallicity a secondary GC population formed in some violent star formation event in the history of its parent galaxy may or may not be detected in the observed GC color distributions. I also investigate the effect of these secondary GCs on the LFs of the total GC system. Significant differences are found among the diagnostic efficiencies in various wavelength regions. In particular, we predict the NIR to be able to reveal the presence of GC subpopulations with different age - metallicity combinations that may perfectly hide within one inconspicuous optical color peak. If the entire manifold of possible age - metallicity combinations is admitted for a secondary GC population, we find several

  14. The population dilemma.

    PubMed

    Kunugi, T

    1990-06-01

    Technology and population rely on each other for sustenance and growth. Technology has helped produce more food, provide better health care, better communication, faster modes of travel, better consumer durables, greater amenities, and increased the quality of life for millions of people. There has been a price in terms of the widening gap between the technology of the developed and developing countries. There has also been rapid population growth that has resulted in a host of ills. Further, technology itself has produced toxic wastes and consumed a large amount of natural resources. This situation is easily seen as a dilemma between the limitless promises of technology and the limited resources created by large populations. The solution to the dilemma is sustainable development, a concept often talked about but seldom realized. The 90s will be a crucial decade for sustainable development as population is growing by 90 million/annum. 90% of the increase is occurring in developing countries. Within each country there is a trend towards urbanization. By 2000, 75% of Latin Americans, 42% of Africans, and 37% of Asians will live in urban environments. By 2050 there should be 100s of millions of migrants running from the slowly rising sea. The survival equation is sustainability S equals resources R time ingenuity 1 over population P. This is a conceptual equation, but it does illustrate that the impact of human ingenuity is just as important as resources. World commitment must come before any meaningful change will occur. The almost universal acceptance of human rights and fundamental freedoms exceeds the will to change in decision makers and expert consultants.

  15. [Population and family planning].

    PubMed

    Romero, H

    1977-12-01

    This work consists of a speech read before the Adacemy of Medicine of the Institute of Chile and a brief debate by members of the audience. Misinformed opponents of birth control who argue among other things that family planning is a US plot ignore the fact that the desire to avoid pregnancy dates from the remote past, as attested by evidence from early Egyptian papyruses. Recent sharp declines in human mortality have led to unprecedented population growth. Around the beginning of the modern era the world contained about 250 million people, a population which did not double until the mid 1600s. Today world population doubles in 30 to 35 years, and by the end of the century it may reach 7 billion. The impact of such growth on the food supply, housing, the economy, education, and the environment have been the object of many studies, predominant among them those presented at the World Population Conferences in Rome, Belgrade, and Bucharest. The family planning program in Chile was initiated around 1962 although some activities had been carried out earlier. The Chilean Association for the Protection of the Family, a private organization, grew out of these early efforts and enjoyed considerable success from its earliest days. The natality rate declined from 38/1000 in 1962 to 23.5/1000 in 1977, and infant and maternal mortality also declined. The decline has been concentrated in births after age 30 and in high parity births. The young age structure means that the population will continue to increase for the foreseeable future.

  16. [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.

  17. [Vietnam and its population].

    PubMed

    Veron, J

    1993-01-01

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

  18. 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.

  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. TB in Vulnerable Populations

    PubMed Central

    Ugarte-Gil, César; Caro, Godofredo; Aylas, Rula; Castro, César; Lema, Claudia

    2016-01-01

    Abstract This article analyzes the factors associated with vulnerability of the Ashaninka, the most populous indigenous Peruvian Amazonian people, to tuberculosis (TB). By applying a human rights-based analytical framework that assesses public policy against human rights standards and principles, and by offering a step-by-step framework for a full assessment of compliance, it provides evidence of the relationship between the incidence of TB among the Ashaninka and Peru’s poor level of compliance with its human rights obligations. The article argues that one of the main reasons for the historical vulnerability of the Ashaninka to diseases such as TB is a lack of political will on the part of the national government to increase public health spending, ensure that resources reach the most vulnerable population, and adopt and invest in a culturally appropriate health system. PMID:27780999

  1. The population explodes.

    PubMed

    Hickcox, S

    1999-01-01

    This letter to the editor refers to an article on the "Baby Boom" published in 1998. The letter notes that no consensus exists among environmentalists about population growth or abortion and calls for more balance in coverage of these issues. The letter points out that, in animal and human populations, a "natural" suppression of reproduction occurs in the presence of a stable ecosystem. However, humans have forever changed the delicate balance of earth's ecosystems. The letter offers China as an example of a country whose drive to become an industrialized power is causing overuse, neglect, and destruction of natural resources. The letter concludes that efforts to obtain sustainability should involve a "more sobering look at free enterprise and the global economy."

  2. Selecting Multinomial Populations

    DTIC Science & Technology

    1990-01-01

    Shannon (1948). The Gini -Simpson index was introduced by Gini ( 1912 ) and Simpson (1949). Both are Schur-concave function of p. In the literature...generalized entropy goodness. Tamkang Journal of Mathematics, 12, 206-208. Gini , C. ( 1912 ). Variabilita e Mutabilit6. Studi Economico-aguridici della...fair multinomial population; entropy function; Gini -Simpson index; natural selection procedure; empirical Bayes selection procedure; asymptotically

  3. 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.

  4. Population and climate change.

    PubMed

    Cohen, Joel E

    2010-06-01

    To review, the four broad dimensions of any complex human problem, including climate change, are the human population, economics, culture, and environment. These dimensions interact with one another in all directions and on many time-scales. From 2010 to 2050, the human population is likely to grow bigger, more slowly, older, and more urban. It is projected that by 2050 more than 2.6 billion people (almost 94% of global urban growth) will be added to the urban population in today's developing countries. That works out to 1.26 million additional urban people in today's developing countries every week from 2010 to 2050. Humans alter the climate by emitting greenhouse gases, by altering planetary albedo, and by altering atmospheric components. Between 1900 and 2000, humans' emissions of carbon into the atmosphere increased fifteenfold, while the numbers of people increased less than fourfold. Population growth alone, with constant rates of emissions per person, could not account for the increase in the carbon emissions to the atmosphere. The world economy grew sixteenfold in the twentieth century, accompanied by enormous increases in the burning of gas, oil, and coal. In the last quarter of the twentieth century, population grew much faster in developing countries than in high-income countries, and, compared with population growth, the growth of carbon emissions to the atmosphere was even faster in developing countries than in high-income countries. The ratio of emissions-to-population growth rates was 2.8 in developing countries compared with 1.6 in high-income countries. Emissions of CO2 and other greenhouse gases are influenced by the sizes and density of settlements, the sizes of households, and the ages of householders. Between 2010 and 2050, these demographic factors are anticipated to change substantially. Therefore demography will play a substantial role in the dynamics of climate changes. Climate changes affect many aspects of the living environment

  5. A study of the human immune response to Lolium perenne (rye) pollen and its components, Lol p I and Lol p II (rye I and rye II). I. Prevalence of reactivity to the allergens and correlations among skin test, IgE antibody, and IgG antibody data.

    PubMed

    Freidhoff, L R; Ehrlich-Kautzky, E; Grant, J H; Meyers, D A; Marsh, D G

    1986-12-01

    In a stratified random sample of 320 white adults, the prevalence of puncture skin test positivity (ST +) to Lolium perenne (rye grass)-pollen extract (LPE) was 16%. Fifteen percent of all subjects (or 84% of subjects classified LPE IgE antibody positive [Ab +]) was classified IgE Ab + to highly purified Lol p I (Rye I), and 4% of all subjects (or 26% of subjects classified LPE IgE Ab +) was classified IgE Ab + to highly purified Lol p II (Rye II). These data and similar results obtained in an allergy-enriched group of 361 subjects are consistent with previous studies that Lol I is a major allergen and Lol II is a minor allergen of LPE. Whether we studied LPE, Lol I, or Lol II, responder subjects were younger than nonresponder subjects and more male than female subjects were responders. We then investigated the quantitative interrelationships among ST, IgE, and IgG Ab responsiveness to LPE, Lol I, and Lol II in the allergy-enriched group. For each allergen, log-log correlations were strong and significant for ST versus IgE Ab and for IgE Ab versus IgG Ab. All subjects IgE Ab + to Lol I or Lol II were IgG Ab + to that allergen, supporting other evidence for a commonality in the genetic control influencing the production of IgE and IgG Abs to a given allergen. Log-log correlations among ST end points, IgE Ab levels, or IgG Ab levels were strong for LPE versus either Lol I or Lol II but weak between Lol I and Lol II, consistent with the reported lack of cross-reactivity between Lol I and Lol II. Despite these findings, almost all Lol II + subjects were Lol I + by ST (98%), IgE Ab (91%), and IgG Ab (83%), suggesting that the Ia-restricted immune recognition of both these molecules is at least in part under a common genetic control.

  6. Population policies and development.

    PubMed

    Stamper, B M

    1984-01-01

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

  7. [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.

  8. Training Manual in Population Education. Population Education Programme Service.

    ERIC Educational Resources Information Center

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

    Population education is at different stages of development in the Asian countries, but almost all of the countries show an interest in developing population education programs. This manual for designing and implementing population education programs consists of six chapters. Chapter one highlights issues and problems arising in connection with…

  9. 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)

  10. 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,…

  11. 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.

  12. 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.

  13. Genetic diversity, population structure, effective population size and demographic history of the Finnish wolf population.

    PubMed

    Aspi, J; Roininen, E; Ruokonen, M; Kojola, I; Vilà, C

    2006-05-01

    The Finnish wolf population (Canis lupus) was sampled during three different periods (1996-1998, 1999-2001 and 2002-2004), and 118 individuals were genotyped with 10 microsatellite markers. Large genetic variation was found in the population despite a recent demographic bottleneck. No spatial population subdivision was found even though a significant negative relationship between genetic relatedness and geographic distance suggested isolation by distance. Very few individuals did not belong to the local wolf population as determined by assignment analyses, suggesting a low level of immigration in the population. We used the temporal approach and several statistical methods to estimate the variance effective size of the population. All methods gave similar estimates of effective population size, approximately 40 wolves. These estimates were slightly larger than the estimated census size of breeding individuals. A Bayesian model based on Markov chain Monte Carlo simulations indicated strong evidence for a long-term population decline. These results suggest that the contemporary wolf population size is roughly 8% of its historical size, and that the population decline dates back to late 19th century or early 20th century. Despite an increase of over 50% in the census size of the population during the whole study period, there was only weak evidence that the effective population size during the last period was higher than during the first. This may be caused by increased inbreeding, diminished dispersal within the population, and decreased immigration to the population during the last study period.

  14. 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.

  15. Population, migration and urbanization.

    PubMed

    1982-06-01

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

  16. The politics of population.

    PubMed

    1994-09-07

    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

  17. 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…

  18. Curricular Renovation through Population Education.

    ERIC Educational Resources Information Center

    de la Cruz, Leonardo

    The document is intended to assist educators in Nepal in implementing curriculum reform or improvement by using population education as a means. Procedural designs that can be followed are described. First, the goals of population education must be defined. Second, a decision has to be made as to which body of knowledge or population concepts are…

  19. Population Education Documents, Reprint Series.

    ERIC Educational Resources Information Center

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

    This publication contains reprints of five documents that were either published in foreign journals or released in limited numbers by author or publisher. The papers are all concerned with population education, but deal more specifically with the role of population and the schools. Among the topics discussed are population education and the school…

  20. 1974 is World Population Year.

    ERIC Educational Resources Information Center

    Asian Population Programme News, 1974

    1974-01-01

    This publication is a special issue of the Asian Population Programme News. This particular publication is concerned with population year 1974. Highlights from the thirtieth session of the Economic Commission for Asia and the Far East (ECAFE) are presented. World, regional, and country population news are included in separate sections. A listing…

  1. 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,…

  2. 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."

  3. 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…

  4. 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.…

  5. The Education of Population Scientists.

    ERIC Educational Resources Information Center

    Malcolm, Janet M.; Cargille, Charles M.

    Population science, a combination of natural science, social science, and management science, deals with the phenomena associated with the human population size. Subjects include the rates of change of the sizes of the various subsets of the human population, the causes and results of those changes, the societal pressures for control of population…

  6. Population Redistribution in the Midwest.

    ERIC Educational Resources Information Center

    Roseman, Curtis C., Ed.; And Others

    The nine chapters in the book focus on the 1970s' metropolitan to nonmetropolitan migration stream and address both population patterns and processes and the impacts and policy issues associated with the resulting population redistribution in the Midwest. Peter A. Morrison places the Midwest in the national context of changing population structure…

  7. Population of the Galaxy

    SciTech Connect

    Troitskii, V.

    1981-09-01

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

  8. [Excessive population and health].

    PubMed

    Rivera, A A

    1995-07-01

    Population density in El Salvador is among the highest in the world. In metropolitan San Salvador and the other main cities, crowding, squatter settlements, unemployment and underemployment, scarcity of basic services, squalor, and other social pathologies appear to be increasing. Overpopulation poses an enormous challenge for development. Reflection on the benefits of family planning has been delayed in El Salvador, and in the interim there have been increases in social inequality, misery, and hunger. Family planning programs have been referred to as "neo-Malthusian" and contrary to the right to life, but in fact they promote birth spacing and free selection of methods by couples, contributing to improvement in the quality of family life. Family planning allows couples to limit their offspring to those they can adequately care for emotionally and materially. People must be shown that family planning alleviates many of humanity's problems.

  9. Population, environment, and development.

    PubMed

    Myers, N

    1993-01-01

    The strategies for reducing population growth include social development and improvement in the educational attainment of women. The decline in Kenya's growth rate was attributed to high female literacy and reduced infant mortality. Another strategy for enhancing fertility decline is to reduce child mortality, particularly from preventable causes such as diarrhea. The entire cost of such a strategy to reduce preventable disease would be about $1.33 per 300 million taxpayers in developed countries. Family planning services must be expanded. Prevention of maternal mortality and AIDS would bring major benefits. Strategies for environmental protection emphasized the already existing plan of action set out in the UNCED document Agenda 21 in Rio de Janeiro. The plan has suffered from inaction. The estimated cost of $625 million was considered to be several times smaller than the costs of inaction. The elimination of subsidies in tropical forests would have an immediate impact. Natural resource accounting at the national level would include the value of natural resources. Pricing would change radically for gasoline if the costs of urban smog, acid rain, low-level ozone pollution, and global warming were taken into account. Strategies for sustainable development pertained to the preceding strategies and others indicated in the Agenda 21 Action Plan. If funding were better targeted to the poorest 20% of global population with high fertility rates, the accomplishments would be heralded. 1.2 million are living in absolute poverty, and aid for nutrition, primary health care, water and sanitation, basic education, and family planning amounts to only 10% of expenditures. An increase to 20% would mean a contribution from Americans of $7.50 per person or 33% of $25 thousand million from all developed countries. Developing countries need to lower their military expenditures, privatize public enterprises, change inappropriate development policies, eliminate corruption, and improve

  10. Population pharmacokinetics of exenatide

    PubMed Central

    Mager, Donald E.

    2016-01-01

    Aim The aim of the present analysis was to develop a core population pharmacokinetic model for the pharmacokinetic properties of immediate‐release (IR) exenatide, which can be used in subsequent analyses of novel sustained‐release formulations. Methods Data from eight clinical trials, evaluating a wide range of doses and different administration routes, were available for analysis. All modelling and simulations were conducted using the nonlinear mixed‐effect modelling program NONMEM. External model validation was performed using data from the phase III clinical trials programme through standard visual predictive checks. Results The pharmacokinetics of IR exenatide was described by a two‐compartment model, and the absorption of subcutaneous exenatide was described with a sequential zero‐order rate constant followed by a saturable nonlinear absorption process. Drug elimination was characterized by two parallel routes (linear and nonlinear), with significant relationships between renal function and the linear elimination route, and between body weight and volume of distribution. For a subject with normal renal function, the linear clearance was estimated to be 5.06 l hr−1. The nonlinear elimination was quantified with a Michaelis–Menten constant (K m) of 567 pg ml−1 and a maximum rate of metabolism (V max) of 1.6 μg h−1. For subcutaneous administration, 37% of the subcutaneous dose is absorbed via the zero‐order process, and the remaining 63% via the nonlinear pathway. Conclusions The present analysis provides a comprehensive population pharmacokinetic model for exenatide, expanding the elimination process to include both linear and nonlinear components, providing a suitable platform for a broad range of concentrations and patient conditions that can be leveraged in future modelling efforts of sustained‐release exenatide formulations. PMID:27650681

  11. 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.

  12. 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.

  13. Population Health and Occupational Therapy.

    PubMed

    Braveman, Brent

    2016-01-01

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

  14. Natural selection and population dynamics.

    PubMed

    Saccheri, Ilik; Hanski, Ilkka

    2006-06-01

    To what extent, and under which circumstances, are population dynamics influenced by concurrent natural selection? Density dependence and environmental stochasticity are generally expected to subsume any selective modulation of population growth rate, but theoretical considerations point to conditions under which selection can have an appreciable impact on population dynamics. By contrast, empirical research has barely scratched the surface of this fundamental question in population biology. Here, we present a diverse body of mostly empirical evidence that demonstrates how selection can influence population dynamics, including studies of small populations, metapopulations, cyclical populations and host-pathogen interactions. We also discuss the utility, in this context, of inferences from molecular genetic data, placing them within the broader framework of quantitative genetics and life-history evolution.

  15. Population pharmacokinetics of daptomycin.

    PubMed

    Dvorchik, Barry; Arbeit, Robert D; Chung, Julia; Liu, Susan; Knebel, William; Kastrissios, Helen

    2004-08-01

    Data from subjects in nine phase 1 (n = 153) and six phase 2/3 (n = 129) clinical trials were combined to identify factors contributing to interindividual variability in daptomycin pharmacokinetics (PK). Over 30 covariates were considered. A two-compartment model with first-order elimination provided the best fit for data on daptomycin concentrations in plasma over time. In the final population PK model, daptomycin plasma clearance (CL) was a function of renal function, body temperature, and sex. Of these factors, renal function contributed most significantly to interindividual variability. CL varied linearly with the estimated creatinine clearance. CL among dialysis subjects was approximately one-third that of healthy subjects (0.27 versus 0.81 liter/h). CL in females was 80% that in males; however, in clinical trials, the outcome was not affected by sex and therefore this effect is not considered clinically meaningful. The relationship with body temperature should be interpreted cautiously since the analysis included only a limited number of subjects who were hyperthermic. The volume of distribution of the peripheral compartment (V2) and intercompartmental clearance (Q) were linearly related to body weight. V2 increased approximately twofold in the presence of an acute infection. No factors were identified that significantly impacted V1. This analysis supports the dosing of daptomycin on a milligram-per-kilogram-of-body-weight basis and suggests that modified dosing regimens are indicated for patients with severe renal disease and for those undergoing dialysis.

  16. Lotus corniculatus condensed tannins decrease in vivo populations of proteolytic bacteria and affect nitrogen metabolism in the rumen of sheep.

    PubMed

    Min, B R; Attwood, G T; Reilly, K; Sun, W; Peters, J S; Barry, T N; McNabb, W C

    2002-10-01

    Condensed tannins in forage legumes improve the nutrition of sheep by reducing ruminal degradation of plant protein and increasing crude protein flow to the intestine. However, the effects of condensed tannins in forage legumes on rumen bacterial populations in vivo are poorly understood. The aim of this study was to investigate the specific effects of condensed tannins from Lotus corniculatus on four proteolytic rumen bacteria in sheep during and after transition from a ryegrass (Lolium perenne)-white clover (Trifolium repens) diet (i.e., low condensed tannins) to a Lotus corniculatus diet (i.e., higher condensed tannins). The bacterial populations were quantified using a competitive polymerase chain reaction. Lotus corniculatus was fed with or without ruminal infusions of polyethylene glycol (PEG), which binds to and inactivates condensed tannins, enabling the effect of condensed tannins on bacterial populations to be examined. When sheep fed on ryegrass-white clover, populations of Clostridium proteoclasticum B316T, Butyrivibrio fibrisolvens C211a, Eubacterium sp. C12b, and Streptococcus bovis B315 were 1.5 x 10(8), 1.1 x 10(6), 4.6 x 10(8), and 7.1 x 10(6) mL(-1), respectively. When the diet was changed to Lotus corniculatus, the average populations (after 8-120 h) of C. proteoclasticum, B. fibrisolvens, Eubacterium sp., and S. bovis decreased (P < 0.001) to 2.4 x 10(7), 1.1 x 10(5), 1.1 x 10(8), and 2.5 x 10(5) mL(-1), respectively. When PEG was infused into the rumen of sheep fed Lotus corniculatus, the populations of C. proteoclasticum, B. fibrisolvens, Eubacterium sp., and S. bovis were higher (P < 0.01-0.001) than in sheep fed Lotus corniculatus without the PEG infusion, with average populations (after 8-120 h) of 4.9 x 10(7), 3.8 x 10(5), 1.9 x 10(8), and 1.0 x 10(6), respectively. Sheep fed the Lotus corniculatus diet had lower rumen proteinase activity, ammonia, and soluble nitrogen (P < 0.05-0.001) than sheep that were fed Lotus corniculatus plus PEG

  17. 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.

  18. Population modeling for furbearer management

    USGS Publications Warehouse

    Johnson, D.H.; Sanderson, G.C.

    1982-01-01

    The management of furbearers has become increasingly complex as greater demands are placed on their populations. Correspondingly, needs for information to use in management have increased. Inadequate information leads the manager to err on the conservative side; unless the size of the 'harvestable surplus' is known, the population cannot be fully exploited. Conversely, information beyond what is needed becomes an unaffordable luxury. Population modeling has proven useful for organizing information on numerous game animals. Modeling serves to determine if information of the right kind and proper amount is being gathered; systematizes data collection, data interpretation, and decision making; and permits more effective management and better utilization of game populations. This report briefly reviews the principles of population modeling, describes what has been learned from previous modeling efforts on furbearers, and outlines the potential role of population modeling in furbearer management.

  19. Global fertility and population trends.

    PubMed

    Bongaarts, John

    2015-01-01

    Over the past several decades, the world and most countries have undergone unprecedented demographic change. The most obvious example of this change is the rise in human numbers, and there are also important trends in fertility, family structure, mortality, migration, urbanization, and population aging. This paper summarizes past trends and projections in fertility and population. After reaching 2.5 billion in 1950, the world population grew rapidly to 7.2 billion in 2013 and the projections expect this total to be 10.9 billion by 2100. World regions differ widely in their demographic trends, with rapid population growth and high fertility continuing in the poorest countries, particularly in sub-Saharan Africa, while population decline, population aging, and very low fertility are now a key concern in many developed countries. These trends have important implications for human welfare and are of interest to policy makers. The conclusion comments briefly on policy options to address these adverse trends.

  20. 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

  1. Population and geography in India.

    PubMed

    Chandna, R C

    1991-01-01

    The field of population geography was first introduced during the 1960s in India and advanced under the direction of Gosal at the Punjab University. Teaching and research in population geography were introduced by Chandigarh at Punjab University, which today is the main center of research activity. Population geography in India has followed the main tenets of geography in general and is based on spatial perspectives. Deficits are apparent in the paucity of research on socioeconomic implications of spatial distributions, but there is infrastructural feedback to support theory development. Theoretical advances moving from theory to fact or from empirical fact to theory are limited. Comprehensive training in methodology and quantitative techniques is needed for further development of population theory: multivariate analysis, factor analysis, principal component analysis, model building, hypothesis testing, and theory formulation. Methodological sophistication will also help in understanding and interpreting the diverse and complex Indian demographic situation. The analysis of population geography in the Indian spatial, cultural, political, and historical context may be applied to other less developed countries of similar sociocultural background. The Indian Census has contributed over the 100 years of its existence reliable and efficiently produced data on a wide variety of measures at assorted scales down to the village level. Field work among geographers has not achieved a level of development commensurate with population censuses. Recent doctoral research has focused on qualitative studies of local situations. Research topics range from the distribution and structure of population, mortality, fertility, and migration to peripheral issues of social segregation. Popular topics include urbanization, labor force, sex composition, literacy, and population growth. Distribution of population and density studies have amounted to only 2 in 30 years. Population texts are in

  2. 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.

  3. Evolutionary dynamics of diploid populations

    NASA Astrophysics Data System (ADS)

    Desimone, Ralph; Newman, Timothy

    2003-10-01

    There has been much recent interest in constructing computer models of evolutionary dynamics. Typically these models focus on asexual population dynamics, which are appropriate for haploid organsims such as bacteria. Using a recently developed ``genome template'' model, we extend the algorithm to a sexual population of diploid organisms. We will present some early results showing the temporal evolution of mean fitness and genetic variation, and compare this to typical results from haploid populations.

  4. The repercussion of population growth.

    PubMed

    Barnes, A C

    1981-08-01

    It is self-evident that, "in a finite world, infinite population growth is impossible." Population growth rates are now higher than ever before in history. In addition, there is a certain level of momentum built in, i.e., even achievement of zero population growth would be accompanied by real increases in the population level due to the age-sex structure of the population. While birth, death, and population growth rates can be calculated arithmetically, their repercussions for quality of life indices cannot. With unlimited population growth, life becomes less worth living. A brief examination is made of the following indices of quality of life and the implications for them of unlimited growth: 1) educational facilities and information media; 2) food and nutrition; 3) housing and clothing; 4) health facilities and sanitation; 5) job availability; 6) waste disposal and the quality of the environment; and 7) energy supply and transportation. Except at the local level, it is unlikely that these facilities can grow exponentially with rapid population growth. Population control must ultimately rest on many individual decisions taken at the personal level.

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

    ERIC Educational Resources Information Center

    Villanueva, Carmelita L., Ed.

    1987-01-01

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

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

    PubMed

    Eyre, C A; Garbelotto, M

    2015-01-01

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

  7. Population Bulletin. World Population Projections: Alternative Paths to Zero Growth.

    ERIC Educational Resources Information Center

    Peck, Jennifer Marks

    1974-01-01

    This report is an adaptation of selected parts of a book on world population projections by Tomas Frejka. An explanation of the demographic terms that form a foundation for these projections is included, as well as discussions of the growth potentials for 24 nations throughout the world. Frejka's projections for a nongrowing population have been…

  8. 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.

  9. 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.

  10. 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.

  11. Stochastic delocalization of finite populations

    NASA Astrophysics Data System (ADS)

    Geyrhofer, Lukas; Hallatschek, Oskar

    2013-01-01

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

  12. 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…

  13. 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…

  14. 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…

  15. World population beyond six billion.

    PubMed

    Gelbard, A; Haub, C; Kent, M M

    1999-03-01

    This world report reviews population growth pre-1900, population change during 1900-50 and 1950-2000, causes and effects of population change and projections to 2050. World population grew from 2 billion in 1900 to almost 6 billion in 2000. Population showed more rapid growth in the 17th and 18th centuries. Better hygiene and public sanitation in the 19th century led to expanded life expectancies and quicker growth, primarily in developed countries. Demographic transition in the 19th and 20th centuries was the result of shifts from high to low mortality and fertility. The pace of change varies with culture, level of economic development, and other factors. Not all countries follow the same path of change. The reproductive revolution in the mid-20th century and modern contraception led to greater individual control of fertility and the potential for rapid fertility decline. Political and cultural barriers that limit access affect the pace of decline. Population change is also affected by migration. Migration has the largest effect on the distribution of population. Bongaarts explains differences in fertility by the proportion in unions, contraceptive prevalence, infertility, and abortion. Educational status has a strong impact on adoption of family planning. Poverty is associated with multiple risks. In 2050, population could reach 10.7 billion or remain low at 7.3 billion.

  16. 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.…

  17. 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...

  18. Stellar populations in star clusters

    NASA Astrophysics Data System (ADS)

    Li, Cheng-Yuan; de Grijs, Richard; Deng, Li-Cai

    2016-12-01

    Stellar populations contain the most important information about star cluster formation and evolution. Until several decades ago, star clusters were believed to be ideal laboratories for studies of simple stellar populations (SSPs). However, discoveries of multiple stellar populations in Galactic globular clusters have expanded our view on stellar populations in star clusters. They have simultaneously generated a number of controversies, particularly as to whether young star clusters may have the same origin as old globular clusters. In addition, extensive studies have revealed that the SSP scenario does not seem to hold for some intermediate-age and young star clusters either, thus making the origin of multiple stellar populations in star clusters even more complicated. Stellar population anomalies in numerous star clusters are well-documented, implying that the notion of star clusters as true SSPs faces serious challenges. In this review, we focus on stellar populations in massive clusters with different ages. We present the history and progress of research in this active field, as well as some of the most recent improvements, including observational results and scenarios that have been proposed to explain the observations. Although our current ability to determine the origin of multiple stellar populations in star clusters is unsatisfactory, we propose a number of promising projects that may contribute to a significantly improved understanding of this subject.

  19. 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…

  20. 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…

  1. 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.

  2. 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)

  3. Population coding in somatosensory cortex.

    PubMed

    Petersen, Rasmus S; Panzeri, Stefano; Diamond, Mathew E

    2002-08-01

    Computational analyses have begun to elucidate which components of somatosensory cortical population activity may encode basic stimulus features. Recent results from rat barrel cortex suggest that the essence of this code is not synergistic spike patterns, but rather the precise timing of single neuron's first post-stimulus spikes. This may form the basis for a fast, robust population code.

  4. Population Education: A New Commitment

    ERIC Educational Resources Information Center

    Cleaver, Betty

    1978-01-01

    Students who understand the relationship between population growth and change and the quality of their life and the life of their children will be better able to make responsible decisions about their world. Discusses the addition of population education to the curriculum, the objectives of teachers and the government in teaching it, and how it…

  5. 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…

  6. 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";…

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. Dose-structured population dynamics.

    PubMed

    Ginn, Timothy R; Loge, Frank J

    2007-07-01

    Applied population dynamics modeling is relied upon with increasing frequency to quantify how human activities affect human and non-human populations. Current techniques include variously the population's spatial transport, age, size, and physiology, but typically not the life-histories of exposure to other important things occurring in the ambient environment, such as chemicals, heat, or radiation. Consequently, the effects of such 'abiotic' aspects of an ecosystem on populations are only currently addressed through individual-based modeling approaches that despite broad utility are limited in their applicability to realistic ecosystems [V. Grimm, Ten years of individual-based modeling in ecology: what have we learned and what could we learn in the future? Ecol. Model. 115 (1999) 129-148][1]. We describe a new category of population dynamics modeling, wherein population dynamical states of the biotic phases are structured on dose, and apply this framework to demonstrate how chemical species or other ambient aspects can be included in population dynamics in three separate examples involving growth suppression in fish, inactivation of microorganisms with ultraviolet irradiation, and metabolic lag in population growth. Dose-structuring is based on a kinematic approach that is a simple generalization of age-structuring, views the ecosystem as a multi-component mixture with reacting biotic/abiotic components. The resulting model framework accommodates (a) different memories of exposure as in recovery from toxic ambient conditions, (b) differentiation between exogenous and endogenous sources of variation in population response, and (c) quantification of acute or sub-acute effects on populations arising from life-history exposures to abiotic species. Classical models do not easily address the very important fact that organisms differ and have different experiences over their life cycle. The dose structuring is one approach to incorporate some of these elements into the

  12. 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.

  13. Farm Population of the United States: 1973. Current Population Reports, Farm Population.

    ERIC Educational Resources Information Center

    Banks, Vera J.; And Others

    Selected characteristics of the United States' farm population for 1973 are presented. The farm population consists of all persons living in rural territory on places of: (1) 10 or more acres if as much as $50 worth of agricultural products were sold from the place in the reporting year and (2) under 10 acres if as much as $250 worth of…

  14. 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…

  15. 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.

  16. 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

  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.

  18. Scientists reinforce population control policies.

    PubMed

    Myers, N

    1994-01-01

    In late October, 1993, 43 national scientific academies convened for 4 days in Delhi, India. This was the first time that so many academies had come together to discuss a topic of common interest: the controversial issue of population in conjunction with environment and development. The New Delhi gathering, known as the Population Summit, came up with a Conference Statement that earned the signatures of almost all participants. The statement proclaimed that ultimate success in dealing with global social, economic, and environmental problems cannot be achieved without stable world population. The goal should be zero population growth within the lifetime of our children. This goal will require prodigious planning efforts. If all couples were to decide right now that they would produce no more than 2 children, the world's population would still keep on growing through demographic momentum for another several decades. The source in shortest supply is probably not money but time. Said the Royal Society and the US National Academy of Sciences in 1993, "If current predictions of population growth prove accurate and patterns of human activity on the planet remain unchanged, science and technology may not be able to prevent irreversible degradation of the natural environment and continued poverty for much of the world ... Some of the environmental changes may produce irreversible damage to the Earth's capacity to sustain life. The future of our planet is in the balance." The Delhi statement was backed by 25 professional papers on subjects such as population history, energy, and water.

  19. Modeling the prehistoric Maori population.

    PubMed

    Brewis, A A; Molloy, M A; Sutton, D G

    1990-03-01

    Skeletal and comparative evidence of mortality is combined with fertility estimates for the precontact Maori population of New Zealand to determine the implied rate of precontact population growth. This rate is found to be too low to populate New Zealand within the time constraints of its prehistoric sequence, the probable founding population size, and the probable population size at contact. Rates of growth necessary to populate New Zealand within the accepted time span are calculated. The differences between this minimum necessary rate and the skeletally derived rate are too large to result solely from inadequacies in the primary data. Four alternative explanations of this conundrum are proposed: 1) skeletal evidence of precontact mortality is highly inaccurate; 2) skeletal evidence of fertility is severely underestimating actual levels; 3) there was very rapid population growth in the earliest part of the sequence up to 1150 A.D., from which no skeletal evidence currently is available; or 4) the prehistoric sequence of New Zealand may have been longer than the generally accepted 1,000-1,200 years. These alternatives are examined, and a combination of the last two is found to be the most probable. The implications of this model for New Zealand prehistory and Oceanic paleodemography are discussed.

  20. On the local stellar populations

    NASA Astrophysics Data System (ADS)

    Fuhrmann, Klaus; Chini, Rolf; Kaderhandt, Lena; Chen, Zhiwei

    2017-01-01

    We present a study of the local stellar populations from a volume-complete all-sky survey of the about 500 bright stars with distances less than 25 pc and down to main-sequence effective temperatures Teff ≥ 5300 K. The sample is dominated by a 93 per cent fraction of Population I stars, only 22 sources (5 per cent) are Population II stars, and 9 sources (2 per cent) are intermediate-disc stars. No source belongs to the halo. By following the mass of the stars instead of their light, the resulting subset of 136 long-lived stars distributes as 22 (16.2 per cent):6 (4.4 per cent):108 (79.4 per cent) for the Population II:intermediate disc:Population I, respectively. Along with the much larger scaleheight reached by Population II, this unbiased census of long-lived stars provides plain evidence for a starburst epoch in the early Milky Way, with the formation of a massive, rotationally supported, and dark Population II. The same conclusion arises from the substantial early chemical enrichment levels, exemplified here by the elements magnesium and iron, as it arises also from the local Population II white dwarfs. The kinematics, metallicity distribution functions, star formation rates, age-metallicity relations, the inventory of young stars, and the occurrence of blue straggler stars are discussed. A potentially new aspect of the survey is the possibility for substructure among the local Population II stars that may further subdivide into metal-poor and metal-rich sources.

  1. Population and Australian development assistance.

    PubMed

    Jones, R

    1992-07-01

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

  2. Evolutionary processes in finite populations

    NASA Astrophysics Data System (ADS)

    Lorenz, Dirk M.; Park, Jeong-Man; Deem, Michael W.

    2013-02-01

    We consider the evolution of large but finite populations on arbitrary fitness landscapes. We describe the evolutionary process by a Markov-Moran process. We show that to O(1/N), the time-averaged fitness is lower for the finite population than it is for the infinite population. We also show that fluctuations in the number of individuals for a given genotype can be proportional to a power of the inverse of the mutation rate. Finally, we show that the probability for the system to take a given path through the fitness landscape can be nonmonotonic in system size.

  3. Inherent randomness of evolving populations.

    PubMed

    Harper, Marc

    2014-03-01

    The entropy rates of the Wright-Fisher process, the Moran process, and generalizations are computed and used to compare these processes and their dependence on standard evolutionary parameters. Entropy rates are measures of the variation dependent on both short-run and long-run behaviors and allow the relationships between mutation, selection, and population size to be examined. Bounds for the entropy rate are given for the Moran process (independent of population size) and for the Wright-Fisher process (bounded for fixed population size). A generational Moran process is also presented for comparison to the Wright-Fisher Process. Results include analytic results and computational extensions.

  4. Population samples and genotyping technology.

    PubMed

    Mack, S J; Sanchez-Mazas, A; Single, R M; Meyer, D; Hill, J; Dron, H A; Jani, A J; Thomson, G; Erlich, H A

    2007-04-01

    The 14th International HLA (human leukocyte antigen) Immunogenetics Workshop (14th-IHIWS) Biostatistics and Anthropology/Human Genetic Diversity project continues the population sampling, genotype data generation, and biostatistic analyses of the 13th International Histocompatibility Workshop Anthropology/Human Genetic Diversity Component, with the overall goal of further characterizing global HLA allele and haplotype diversity and better describing the relationships between major histocompatibility complex diversity, geography, linguistics, and population history. Since the 13th Workshop, new investigators have and continue to be recruited to the project and new high-resolution class I and class II genotype data are being generated for 112 population samples from around the world.

  5. 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

  6. 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

  7. Inherent randomness of evolving populations

    NASA Astrophysics Data System (ADS)

    Harper, Marc

    2014-03-01

    The entropy rates of the Wright-Fisher process, the Moran process, and generalizations are computed and used to compare these processes and their dependence on standard evolutionary parameters. Entropy rates are measures of the variation dependent on both short-run and long-run behaviors and allow the relationships between mutation, selection, and population size to be examined. Bounds for the entropy rate are given for the Moran process (independent of population size) and for the Wright-Fisher process (bounded for fixed population size). A generational Moran process is also presented for comparison to the Wright-Fisher Process. Results include analytic results and computational extensions.

  8. 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.

  9. Population and resources in Mauritius.

    PubMed

    Royle, S A

    1995-05-01

    "The island of Mauritius was facing a crisis by the 1950s as the relationship between its population and resources became unbalanced....A two-pronged strategy was set in place to change the relationship between population and resources. Firstly, an aggressive family-planning policy was established, reducing population growth. Secondly, the economy was diversified with tourism, financial services and, especially, manufacturing in the Mauritius Export Processing Zone, creating extra finance and resources. The changes have not been cost-free but Mauritius ends the century, not as a classic case of overpopulation, but more [as] a model micro-state that has overcome many population and resource problems, largely through its own efforts."

  10. Asthma in the geriatric population.

    PubMed

    Madeo, Jennifer; Li, Zhenhong; Frieri, Marianne

    2013-01-01

    Asthma is associated with significant morbidity and mortality in the geriatric population. Despite the rising incidence of asthma in people >65 years of age, the diagnosis is frequently missed in this population. Factors that contribute to this include respiratory changes caused by aging, immunosenescence, lack of symptoms, polypharmacy, clinician unawareness, and lack of evidence-based guidelines for diagnosis and management that target this population. This literature review addresses the current state of research in this area. Age-related changes influence the pathophysiology and role of allergy in elderly asthmatic patients. Specific obstacles encountered in caring for these patients are discussed. Asthma in the elderly and younger population are compared. We conclude with a broad set of goals to guide future management driven by a multidiscipline approach.

  11. 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.

  12. 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)

  13. 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.

  14. Effective Sizes for Subdivided Populations

    PubMed Central

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

    1993-01-01

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

  15. Sahel moves on population policies.

    PubMed

    1992-10-01

    The Sahel region is comprised of Burkina Faso, Cape Verde, Chad, the Gambia, Guinea-Bissau, Mali, Mauritania, Niger, and Senegal. It is one of the poorest regions on earth. 44 million people live in the Sahel countries with a life expectancy of 49 years and more than one out of every eight babies die during infancy. The rate of contraceptive prevalence is no higher than 11% for any of the countries and women have an average of 6.5 births during their lifetimes; the rate of natural population growth is 3.1% per year. Delegates from the Sahel region countries met in Chad in 1989 to discuss population and development issues. Formulating the N'Djamena Plan of Action on Population and Development in the Sahel, the countries have been moving fast on the issues ever since. By the convening of the population policy conference held in Dakar, Senegal, July 1992, Senegal, Burkina Faso, Mali, and Niger had adopted population policies, the Gambia planned to adopt one later in the year, and policies or programs were in progress in each of the other countries. This progress indicates a new commitment to population issues. There was a great deal of solidarity at the 1992 population talks, with participants recognizing the challenge posed by rapid population growth in the context of their economic situations. Concern was expressed for the need to address the health and status of women and children, with a call for specific actions to translate policy rhetoric into action and results. Moreover, compared to the 1989 talks, the 1992 Sahel meeting involved more open discussion of family planning and was attended by a greater number of women delegates.

  16. Population pressures: threat to democracy.

    PubMed

    1992-06-01

    The desire for political freedom and representative government is spreading throughout the world. The stability of democratic bodies is dependent on wise leaders, foreign aid, and slowing population growth. Rapid population growth strains political institutions and increases pressure on services. A Population Crisis Committee study found that only a few democratic countries with serious demographic pressures remained stable. The most stable countries were ones with lower levels of population pressure. Most of the 31 unstable countries were in Africa and in a band stretching from the Middle East to South Asia, and almost all had serious demographic pressures. Only 5 stable countries had high or very high demographic pressures. Since countries in the world are interdependent, population pressures have adverse consequences everywhere. Population pressures in the developing world are considered enhanced by the rapid growth of cities. Both the developed and the developing world face the problems of clogged highways, loss of wilderness, polluted lakes and streams, and stifling smog and acid rain conditions. The sociopolitical implications of demographic changes vary from country to country, but rapid growth and maldistribution of population strains existing political, social, and economic structures and relations between nations. Urban areas are the arena for clashes of cultures, competition for scarce housing and jobs, the breakdown of traditional family and social structures, and juxtapositions of extreme wealth next to extreme poverty. The growth of independent nation states since the 1940s has not allowed much time for development of effective political institutions. There are many obstacles to national unity and popular political participation. The potential for political instability is correlated with a number of factors: large youth populations in overcrowded cities with too high expectations and limited opportunities, diverse and intense ethnic and religious

  17. 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

  18. Population, education and sustainable development.

    PubMed

    Johnston, T

    1992-12-01

    The author examines the interrelationships between population growth and education, with a focus on Sub-Saharan Africa. "The gross body of evidence suggests that for all developing regions (and for sub-saharan Africa specifically) rapid population growth deleteriously impacts upon the quantity and quality of schooling. In a reciprocal fashion, the variables which underpin rapid and differential growth (fertility, mortality and migration) are themselves influenced by quantum of formal schooling and by other educational processes."

  19. Demography, destiny and population policies.

    PubMed

    Findlay, A M; Borgegard, L E

    1995-07-01

    This article considers the aftermath of the 1994 Cairo Conference on Population and Development and the later Laxon, Sweden meeting of about 40 academic geographers, who addressed the implications of the Plan of Action for national policy. A recent International Union for the Scientific Study of Population (IUSSP) member synthesized conference impact on member nations. Martens from IUSSP offered the critique that the 381 recommendations were philosophically incoherent and poorly integrated and did not distinguish between government as a "doer of things" from government as "organizer and guarantor of a legal-institutional framework for allowing individuals and voluntary groups to seek improvements." This article discusses the apparent gulf between the views of population researchers and that of policy makers. It is reasoned that population policies do matter. The Club of Rome world model confirmed rapid population growth during 1972-90. Population policies in the past emphasized a societal perspective rather than an individual one. Policies impact on individual decision making. Most population geographers emphasize four features of social change. 1) Policy must address suitable measures for easing social, economic, and political tensions that arise in the temporary experience of high population growth. 2) More sensitive models of demographic behavior need to be developed, in order to account for the highly uneven patterns of fertility and mortality. Policy should not focus exclusively on family planning and should take into account the cultural and socioeconomic context. 3) Migration pressures from poor to rich countries have increased. Policy should address international migration. 4) People adapt quickly to new policy measures and apply policies effectively in their own life. Policies fail when the top-down approach does not include adequate research into values and behavior of the persons most affected by policy. These four points were discussed throughout this

  20. [Population problems in Latin America].

    PubMed

    Faissol, S

    1990-01-01

    Accelerated urban growth is one of the main impediments to rapid development in Latin America. Birth rates are closely tied to development, and improved living standards in urban areas induce migration to cities. The Brazilian urban population exceeded 70% of the total population in 1980, while rural population declined. During the period of 1950-70 high demographic growth occurred as a result of high fertility and the drop of mortality. From the 1970s fertility declined from the under 20 years of age, a fact that will sustain high fertility for sometime. Education exerted an impact on fertility: in 1980 illiterate women averaged 6 children vs. 2.6 children for women with 8 years of education and 2.2 children for those with 12 years. Migration was another major factor: in 1950 the urban population of Latin America amounted to 40 million, and it reached 142 million in 1974. Every year about 8.7 million people are added to the urban population. In 1950 those who resided in an urban area made up 9.2%, in 1975 they increased to 22%, but all urban residents amount to about 40% of the total population. This urbanization has also produced major income differentials. In Argentina 20% of the poorest people get 4.5% of total income, while 10% of the richest get 35%. In Brazil 20% of the poorest receive 2% of income, while 10% of the richest get 50.5% of total income. Unfortunately, the Brazilian model is more typical of Latin America. It is a fundamental premise that balanced population growth and economic development go hand in hand, and the improvement of living standards is essential for the reduction of exponential population growth.

  1. Quasispecies theory for finite populations

    NASA Astrophysics Data System (ADS)

    Park, Jeong-Man; Muñoz, Enrique; Deem, Michael W.

    2010-01-01

    We present stochastic, finite-population formulations of the Crow-Kimura and Eigen models of quasispecies theory, for fitness functions that depend in an arbitrary way on the number of mutations from the wild type. We include back mutations in our description. We show that the fluctuation of the population numbers about the average values is exceedingly large in these physical models of evolution. We further show that horizontal gene transfer reduces by orders of magnitude the fluctuations in the population numbers and reduces the accumulation of deleterious mutations in the finite population due to Muller’s ratchet. Indeed, the population sizes needed to converge to the infinite population limit are often larger than those found in nature for smooth fitness functions in the absence of horizontal gene transfer. These analytical results are derived for the steady state by means of a field-theoretic representation. Numerical results are presented that indicate horizontal gene transfer speeds up the dynamics of evolution as well.

  2. Quasispecies theory for finite populations

    PubMed Central

    Park, Jeong-Man; Muñoz, Enrique; Deem, Michael W.

    2015-01-01

    We present stochastic, finite-population formulations of the Crow-Kimura and Eigen models of quasispecies theory, for fitness functions that depend in an arbitrary way on the number of mutations from the wild type. We include back mutations in our description. We show that the fluctuation of the population numbers about the average values are exceedingly large in these physical models of evolution. We further show that horizontal gene transfer reduces by orders of magnitude the fluctuations in the population numbers and reduces the accumulation of deleterious mutations in the finite population due to Muller’s ratchet. Indeed the population sizes needed to converge to the infinite population limit are often larger than those found in nature for smooth fitness functions in the absence of horizontal gene transfer. These analytical results are derived for the steady-state by means of a field-theoretic representation. Numerical results are presented that indicate horizontal gene transfer speeds up the dynamics of evolution as well. PMID:20365394

  3. 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.

  4. 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

  5. Environmental pollution and population policies.

    PubMed

    1980-04-01

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

  6. Evolutionary dynamics in finite populations

    NASA Astrophysics Data System (ADS)

    Hauert, Christoph

    2013-03-01

    Traditionally, evolutionary dynamics has been studied based on infinite populations and deterministic frameworks such as the replicator equation. Only more recently the focus has shifted to the stochastic dynamics arising in finite populations. Over the past years new concepts have been developed to describe such dynamics and has lead to interesting results that arise from the stochastic, microscopic updates, which drive the evolutionary process. Here we discuss a transparent link between the dynamics in finite and infinite populations. The focus on microscopic processes reveals interesting insights into (sometimes implicit) assumptions in terms of biological interactions that provide the basis for deterministic frameworks and the replicator equation in particular. More specifically, we demonstrate that stochastic differential equations can provide an efficient approach to model evolutionary dynamics in finite populations and we use the rock-scissors-paper game with mutations as an example. For sufficiently large populations the agreement with individual based simulations is excellent, with the interesting caveat that mutation events may not be too rare. In the absence of mutations, the excellent agreement extends to small population sizes.

  7. The Soviet Union and population: theory, problems, and population policy.

    PubMed

    Di Maio, A J

    1980-04-01

    Until the important public dialog on 3rd World population issues began in the Soviet Uuion in 1965, ideological limitations and bureaucratic interests prevented policy makers from recognizing the existence of a world of national "population problem." Since then, freer discussions of the Soviet Union's surprising decline in birthrate and labor shortages have led to serious policy questions. Conflicting policy goals, however, have resulted in only modest pronatalist policies. The Soviet population problem is a result of interregional disparities in population growth rates between the highly urbanized Soviet European populations with low birth rates and the least urbanized Central Asians with dramatically higher birth rates. As a result, these essentially Muslim people will provide the only major increases in labor resources and an increasing percentage of Soviet armed forces recruits. Policy planners are thus faced with difficult options. Current policies stressing technological transfers from the west and greater labor productivity, however, are unlikely to solve further labor shortages and regional imbalances. Ultimately, nonEuropana regions will be in an improved bargaining position for more favorable nationwide economic policies and for a greater role in policy planning.

  8. 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

  9. 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.

  10. 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

  11. 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.

  12. 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…

  13. 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

  14. Population growth, inequality and poverty.

    PubMed

    Rodgers, G

    1983-01-01

    In this discussion of population growth, inequality, and poverty, the type of relationships that can be observed in intercountry comparisons are explored, reviewing the findings of several other authors, presenting some new estimates using an International Labor Office data bank, considering some basic conceptual problems, and examining some of the theoretical and empirical issues that call for investigation at the national level. Intercountry comparisons, despite their limitations, appear to be the easiest starting point for empirical analysis. The approach adopted by most researchers has been to select 1 or more population indicators and a measure of national income inequality and to explain intercountry differences in 1 or both of these variables in terms of each other and of other indicators of economic and social development. Underlying this methodology is the assumption that there are aspects of demographic and economic change that are common to all countries included in the study, so that differences between countries give some guide to the likely evolution over time within any 1 country. This can be accepted at best with reservations, but given the scarcity of data on the evolution of inequality over time, a working hypothesis of this type appears unavoidable. But, as many of the factors likely to cause population growth and inequality operate over extended periods of time, a dynamic model is indicated. A simpler model, which pays particular attention to lags and variations over time, may generate new insights. A summary of the results of a new international cross-section analysis set up on these lines is presented. Results suggest that contrary to expectations, reducing population growth does not seem to generate longterm benefits for the poor in this model, though some short term gains are found. Increasing equality does appear to generate some decline in population growth, as well as persistent gains in incomes among the poor, but the reductions in

  15. Microbial populations in contaminant plumes

    USGS Publications Warehouse

    Haack, S.K.; Bekins, B.A.

    2000-01-01

    Efficient biodegradation of subsurface contaminants requires two elements: (1) microbial populations with the necessary degradative capabilities, and (2) favorable subsurface geochemical and hydrological conditions. Practical constraints on experimental design and interpretation in both the hydrogeological and microbiological sciences have resulted in limited knowledge of the interaction between hydrogeological and microbiological features of subsurface environments. These practical constraints include: (1) inconsistencies between the scales of investigation in the hydrogeological and microbiological sciences, and (2) practical limitations on the ability to accurately define microbial populations in environmental samples. However, advances in application of small-scale sampling methods and interdisciplinary approaches to site investigations are beginning to significantly improve understanding of hydrogeological and microbiological interactions. Likewise, culture-based and molecular analyses of microbial populations in subsurface contaminant plumes have revealed significant adaptation of microbial populations to plume environmental conditions. Results of recent studies suggest that variability in subsurface geochemical and hydrological conditions significantly influences subsurface microbial-community structure. Combined investigations of site conditions and microbial-community structure provide the knowledge needed to understand interactions between subsurface microbial populations, plume geochemistry, and contaminant biodegradation.

  16. 25th anniversary. Population education.

    PubMed

    Tagle Ra

    1998-01-01

    The Population Education Program's (POPED) main areas of concern are family life and responsible parenthood; gender and development; population and reproductive health; and population, resources and environment, and sustainable development. POPED celebrated its 25th year of existence during October 6-8, 1997, at a National Convention in Davao City organized by the Department of Education, Culture, and Sports (DECS) and its governmental partner agencies, including the Philippine Population Commission (POPCOM), the Department of Health (DOH), and others. The event was held to update POPED stakeholders on current trends and developments in the program and to strengthen existing partnerships between government organizations and nongovernmental organizations (NGOs). The convention also allowed the sharing of 25 years of experience, a chance to generate recommendations for improving the program, and the opportunity to seek greater commitment to POPED's cause from all concerned parties. Rapid population growth and its consequences, integrating family planning into all fields of study, core messages, and the future lifestyle of Filipino youths are discussed.

  17. 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.

  18. 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.

  19. Laplacian eigenfunctions learn population structure.

    PubMed

    Zhang, Jun; Niyogi, Partha; McPeek, Mary Sara

    2009-12-01

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

  20. Population problem in third world.

    PubMed

    Joshi, N C

    1979-04-01

    Since numerous variables influence this growth rate, a holistic approach to the problem is mandatory. Fertility rates in developing countries remain high, not as a result of irrational behavior on the part of the people living in these countries, but as a result of their rational response to high infant mortality rates. Fertility rates will remain high unless the educational, health, and social environment in which these families live is improved. Economic development and population growth are intimately related. Development reduces the death rate resulting in increased population growth, which in turn reduces per capita income. In the developed nations, economic development occurred along with the development of new technologies and the reduction in mortality; therefore, population growth created an effective demand which further stimulated economic development. In developing countries the situation is different. Reduced mortality, the introduction of labor saving technology, and the high consumption aspirations derived from contact with capitalistic countries, have preceded economic development. Given the highly complex nature of the population problem, efforts must be made on many fronts including: 1) family planning promotion; 2) improvements in education, health, and social conditions for high fertility populations; 3) enhancement of worker skills; 4) rapid progress in technology; 5) greater capital accumulation and 5) economic reorganization.

  1. 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.

  2. The Evolution of Stellar Populations

    NASA Astrophysics Data System (ADS)

    DÍaz, Angeles I.; Hardy, Eduardo

    We summarize the discussion section on `Evolution of Stellar Populations' we led on May 27, 2000 in Granada, Spain, as part of the Euroconference on The Evolution of Galaxies. I- Observational Clues. The discussion was organized around two groups of topics. In the first, Population Synthesis, the accent was partially placed on the use of tools and techniques centered around the question of the unicity of the models, their sensitivity to input and the question of the age-metallicity degeneracy. In the second group, Stellar Systems a stronger accent was placed on astrophysical questions, although we included there the need for `truth tests' that apply spectral synthesis techniques to objects for which there is detailed a priori knowledge of their stellar populations. We also provide a partial comparison between the present knowledge of these topics and that which existed at the time of the Crete Conference of 1995.

  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. Keynes, population, and equity prices.

    PubMed

    Tarascio, V J

    1985-01-01

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

  5. Population dynamics and rural poverty.

    PubMed

    Fong, M S

    1985-01-01

    An overview of the relationship between demographic factors and rural poverty in developing countries is presented. The author examines both the micro- and macro-level perspectives of this relationship and the determinants and consequences of population growth. The author notes the prospects for a rapid increase in the rural labor force and considers its implications for the agricultural production structure and the need for institutional change. Consideration is also given to the continuing demand for high fertility at the family level and the role of infant and child mortality in the poverty cycle. "The paper concludes by drawing attention to the need for developing the mechanism for reconciliation of social and individual optima with respect to family size and population growth." The need for rural development projects that take demographic factors into account is stressed as is the need for effective population programs. (summary in FRE, ITA)

  6. 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...

  7. OVERCOMING OBSTACLES TO POPULATIONS RISK ASSESSMENT

    EPA Science Inventory

    Driven by management goals, statutory requirements and stakeholder interests, populations of wildlife and aquatic organisms often are the assessment endpoint entities (assessment populations) identified in site-specific ecological risk assessments. Yet, risks to populations are ...

  8. 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)

  9. Population distribution and internal migration.

    PubMed

    1994-07-01

    In China, population density is about 3 times higher than the world average. Currently, 94% of the population inhabit the developed eastern and southeastern parts of the country, which account for only 46% of China's territory. In contrast, the western and northwestern parts of China contain only 6% of the total population. From 1949 to 1990, the urban population grew from almost 57.7 million to 301.9 million. The strategy of urbanization is to strictly limit the size of large cities and to develop medium-sized and small cities in line with the level of economic development. From 1980 to 1990 the number of cities increased from 223 to 461 and the number of towns from 2874 to 55,000. The overwhelming majority of China's population still live in the countryside. According to the 1990 national population census, during the period from July 1, 1985, to July 1, 1990, the total number of migrants in China reached 34.13 million, of whom 18.83 million were male and 15.30 million were female. There were 23.02 million intra-provincial migrants and 11.07 million inter-provincial migrants. Among the causes of migration: 1) 14.67 million people migrated for job transfers, business, and recruitment, 2) 11.68 million migrated to live with relatives and for marriage, 3) 4.14 million migrated to study and for training. In addition, 3.64 million migrated because of retirement or for other reasons. The number of migrants nationwide topped 100 million in 1992, which is attributed to the large rural surplus labor force flowing into urban areas. Moreover, imbalanced regional economic development and the booming tourist industry have also added to population mobility. More than 40 million rural migrants are outside their official place of residence. The large size of the migrant population has brought about serious problems in increased city traffic and public security. The government is committed to controlling the surplus rural laborers by enabling this segment to migrate to those

  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. The challenge of population growth.

    PubMed

    Smith, A W

    1984-03-02

    A precarious balance exists on earth between food and people, and at this time 800 million people are starving or close to starvation. When agriculture began, say 10,000 years ago, human populations were low. They stayed roughly in balance with the food supply. After agriculture, food supplies increased as did populations. The discovery of the New World opened vast resources, more land. Human numbers began to climb. Inventions and machines increased the ability to exploit resources. With modern medicine came a decline in death rates while birthrates remained high. The result is the 20th century population now totals 4.7 billion. By 2000, it will probably reach 6.1 billion and 7.8 billion by 2020. There will be insufficient cropland to produce the food all these people will need. People have been moving into sprawling urban centers of the poor countries. They come in search of jobs because there is not enough land to support them in rural areas. They increase the numbers of the unemployed and live in squalid shanty towns. Each agricultural or industrial advance that has occurred has been overwhelmed by ever increasing numbers of people in many less developed nations. There appears to be no "catching up" with the world's soaring rate of population. About 40 years ago this dilemma began to alarm some people. Fairfield Osborn and William Vogt believed that food and economic aid should continue but would be only a stopgap until developing countries were able to control their population growth. This meant cutting the birthrate. They reasoned that the best way to accomplish this was to educate people about contraceptives and other methods of limiting fertility. Private foundations funded educational programs, and many governments began giving out contraceptives at little or no cost. Despite such efforts, populations continued to increase in places that could least support more people. Already controversial, population control programs began to offer various incentives to

  12. Burst Populations and Detector Sensitivity

    NASA Technical Reports Server (NTRS)

    Band, David L.

    2003-01-01

    The F(sub T) (peak bolometric photon flux) vs. E(sub p) (peak energy) plane is a powerful tool to compare the burst populations detected by different detectors. Detector sensitivity curves in this plane demonstrate which burst populations the detectors will detect. For example, future CZT-based detectors will show the largest increase in sensitivity for soft bursts, and will be particularly well- suited to study X-ray rich bursts and X-ray Flashes. Identical bursts at different redshifts describe a track in the F(sub T)-E(sub p) plane.

  13. 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.

  14. Attitudes on the Population Explosion

    ERIC Educational Resources Information Center

    Stronck, David R.

    1971-01-01

    Attitudes of biology teachers, prospective teachers, high school students, and adults were compared in regard to the basic principles of Zero Population Growth, the teaching of controversial topics, future state of the world, and Garret Hardin's Graduated Checklist of (28) Heresies." (CP)

  15. 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.

  16. Population Change and California's Future.

    ERIC Educational Resources Information Center

    Bouvier, Leon F.; Martin, Philip

    This report examines how demographic changes, particularly in immigration and fertility, have affected and will continue to affect every segment of California's population. Three points are emphasized in the report: the number and type of Californians in future years, the size and composition of the labor force and the related issues resulting…

  17. 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,…

  18. 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.

  19. 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…

  20. Initiating Population Education in Baltimore

    ERIC Educational Resources Information Center

    Cochran, Caroline S.; McCrea, Lester C.

    1974-01-01

    After identifying the need for population education in Baltimore City Schools, the school system had the problem of initiating such a course. Working with the Planned Parenthood Association of Maryland, the school system sponsored an in-service program for teachers that resulted in the production of materials for all grades. (MA)

  1. 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.

  2. 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…

  3. Why Audubon has population programmes.

    PubMed

    Baldi, P

    1991-01-01

    The National Audubon Society began a population program in 1979, set up a 5-year plan of public education, advocacy and coalition-building in 1985, and joined a broad-based coalition of the Sierra Club, the National Wildlife Federation, the Population Crisis Committee and the Planned Parenthood Federation of America in 1990. The 1985 impetus resulted in production of teaching materials and staging of focus groups across the U.S. The 1990 coalition has directed funds to the USAID Office of Population. Another project is the International Environment/Population Network, which organizes letter-writing, media programs and town meetings for ordinary citizens to press for sustainable development. Many of the Audubon's 510 local chapters have partnerships with similar groups in other countries, as do 8 wildlife sanctuaries have links to sanctuaries abroad. An example is the Indus River in Pakistan visited by the manager of Audubon's Platte River Sanctuary in Nebraska. The 2 rivers share the problem of reduced flow and vegetation overgrowth as a result of engineering projects upstream.

  4. 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.

  5. Communication Disorders in Multicultural Populations.

    ERIC Educational Resources Information Center

    Battle, Dolores E., Ed.

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

  6. Population conference: consensus and conflict.

    PubMed

    Willson, P D

    1984-01-01

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

  7. China fulfills 1991 population plan.

    PubMed

    Peng, P

    1992-06-01

    Minister Peng of the State Family Planning (FP) Commission of China's remarks are summarized. A major new achievement in 1991 was the meeting of population targets in FP. The birth rate for 1991 was 19.68/1000, which was lower than the 1991 target by .118%. The rate of natural increase was 12.98/1000, which was also lower. 1991 marks the lowest population increase in 6 years. Even though those 20-29 years and those at peak childbearing years increased over 1990, the rate of natural increase still declined by .1%. The decline is attributed to the strengthening of all Party leadership over FP; to more widespread publicity and education on FP and acceptance; more conscientious contraception, including permanent methods, and effective FP research; and strengthening of grassroots level FP. 1992 is the year of the 3rd baby boom peak since 1949. 318.9 million will be of childbearing age in 1992, which is an increase of 4.1 million; 13.25 million will be those at the peak age (23 years); 123.7 million will be fecund ages (20-29 years). Continued work is required in strengthening FP, in improving management of population and FP targets, in extensive and penetrating publicity on FP, on consistent and focused FP policy implementation, on increasing input for FP programs, and on pooling government and society's resources for administration of the population problem. Conscientious FP means responsibility and urgency in implementation, FP as a priority, and active FP effort. Earnest FP means using "down to earth" grassroots implementation which is painstaking and meticulous. Persistent FP means unremitting effort in a longterm struggle in controlling population growth. The quality of statistics needs to be improved as well as better criteria for assessment. Emphasis should be on the socioeconomic benefits of the FP program. The focus is still rural areas. The operating funds for FP have been increased to 2 yuan RMB per capita/year. Minorities should practice FP, and a conference

  8. 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

  9. 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

  10. 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

  11. 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

  12. [Population: evolution of Rwandan attitudes or the adaptation of the Rwanda population to population growth].

    PubMed

    Ngendakumana, M

    1988-04-01

    A consequence of the increasing pressure on Rwanda's ecosystem resulting from population growth has been that demographic factors have played a significant role in modifying attitudes and beliefs of the population. The history of Rwanda demonstrates a constant struggle for survival in the face of increasing population pressure. Migration, colonization of new agricultural lands, adoption of new crops and new forms of animal husbandry have been responses to population pressures. Recent unprecedented population growth has exceeded the capacity of older systems of cultivation and combinations of agricultural and animal husbandry to support the population. Smaller animals have largely replaced the cattle that once roamed freely in extensive pastures, and new techniques of stabling animals, use of organic or chemical fertilizers, and new tools adapted to the shrinking size of farm plots have represented responses to the new demographic realities. The concept of the family is likewise undergoing modification in the face of population growth and modernization. Children, who once were valued as a source of labor and constrained to conform to the wishes of the parents in return for the eventual inheritance of the goods and livelihood, now increasingly look beyond the household for education and employment. Family land holdings have become too small to support all the members with a claim on them. The greater distances between family members inevitably mean that relations between them lose closeness. The choice of a marriage partner is increasingly assumed by the young people themselves and not by their families. Old traditions of food sharing and hospitality have been curtailed because of the increasing scarcity of food. Despite the changes engendered by increasing population pressure, pronatalist sentiments are still widespread. But the desire to assure the future of each child rather than to await his services, a new conception of women less dependent on their reproductive

  13. Population Analysis: A Methodology for Understanding Populations in COIN Environments

    DTIC Science & Technology

    2008-12-01

    predict cause and effect of human 30 behavior. In the late 19th century, Wilhelm Wundt founded the first psychology department at the University of...on the application of power with respect to managing people, organizations, markets, and populations. Philosophers and authors such as Friedrich ... Nietzsche , Jeffery Pfeffer, Bertram Raven, and John French have each laid out models by which power, and its implementation can be better understood

  14. 45 CFR 1356.81 - Reporting population.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 4 2011-10-01 2011-10-01 false Reporting population. 1356.81 Section 1356.81... § 1356.81 Reporting population. The reporting population is comprised of all youth in the following categories: (a) Served population. Each youth who receives an independent living service paid for or...

  15. 45 CFR 1356.81 - Reporting population.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Reporting population. 1356.81 Section 1356.81... § 1356.81 Reporting population. The reporting population is comprised of all youth in the following categories: (a) Served population. Each youth who receives an independent living service paid for or...

  16. 45 CFR 1356.81 - Reporting population.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 4 2014-10-01 2014-10-01 false Reporting population. 1356.81 Section 1356.81... § 1356.81 Reporting population. The reporting population is comprised of all youth in the following categories: (a) Served population. Each youth who receives an independent living service paid for or...

  17. 45 CFR 1356.81 - Reporting population.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 4 2013-10-01 2013-10-01 false Reporting population. 1356.81 Section 1356.81... § 1356.81 Reporting population. The reporting population is comprised of all youth in the following categories: (a) Served population. Each youth who receives an independent living service paid for or...

  18. 45 CFR 1356.81 - Reporting population.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 4 2012-10-01 2012-10-01 false Reporting population. 1356.81 Section 1356.81... § 1356.81 Reporting population. The reporting population is comprised of all youth in the following categories: (a) Served population. Each youth who receives an independent living service paid for or...

  19. 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…

  20. 1984 Population Trends for Washington State.

    ERIC Educational Resources Information Center

    Washington State Office of Financial Management, Olympia.

    As of April 1, 1984, Washington's population was estimated at 4,328,100, an increase of 43,000 over last year's population. This report provides data pertaining to the: official April 1, 1984 population and housing estimates for cities, towns, and counties and components of population change. The following special reports are also presented:…

  1. Information in Support of Population Activities.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Paris (France).

    As part of UNESCO's World Population Year, information services in support of population programs are explained and listed. The information system of the International Planned Parenthood Federation is described and the management of population literature discussed. Information needs of population workers and special aspects of the training and…

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

    PubMed

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

    2009-09-01

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

  3. 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.

  4. [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.

  5. Comorbidity in the Tunisian population.

    PubMed

    Romdhane, L; Messaoud, O; Bouyacoub, Y; Kerkeni, E; Naouali, C; Cherif Ben Abdallah, L; Tiar, A; Charfeddine, C; Monastiri, K; Chabchoub, I; Hachicha, M; Tadmouri, G O; Romeo, G; Abdelhak, S

    2016-03-01

    Genetic diseases in the Tunisian population represent a real problem of public health as their spectrum encompasses more than 400 disorders. Their frequency and distribution in the country have been influenced by demographic, economic and social features especially consanguinity. In this article, we report on genetic disease association referred to as comorbidity and discuss factors influencing their expressivity. Seventy-five disease associations have been reported among Tunisian families. This comorbidity could be individual or familial. In 39 comorbid associations, consanguinity was noted. Twenty-one founder and 11 private mutations are the cause of 34 primary diseases and 13 of associated diseases. As the information dealing with this phenomenon is fragmented, we proposed to centralize it in this report in order to draw both clinicians' and researcher's attention on the occurrence of such disease associations in inbred populations as it makes genetic counseling and prenatal diagnosis challenging even when mutations are known.

  6. Dust Devil Populations and Statistics

    NASA Astrophysics Data System (ADS)

    Lorenz, Ralph D.; Jackson, Brian K.

    2016-11-01

    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.

  7. Modern pesticides and bobwhite populations

    USGS Publications Warehouse

    Stromborg, K.L.; Schitoskey, Frank=; Schitoskey, Elizabeth C.; Talent, Larry G.

    1982-01-01

    Bobwhite (Colinus virginianus) are frequently used as test animals for wildlife tests of pesticides. The organophosphate and carbamate pesticides that have replaced the organochlorines have many desirable properties, but they span a wide range of acute toxicities and some of them affe,ct survival, reproduction, food consumption, behavior, and nervous system enzymes in laboratory tests. Applying these laboratory findings to the field requires assumptions about the severity of exposure in the field. Direct field measurements show that birds may be exposed to significant amounts of these pesticides or even more toxic degradation products under some conditions. Adverse population effects may also result from depression of insect populations during the seasons when bobwhites rely on insects for food.

  8. 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.

  9. Statistical thermodynamics of clustered populations.

    PubMed

    Matsoukas, Themis

    2014-08-01

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

  10. Phase switching in population cycles

    PubMed Central

    Henson, S. M.; Cushing, J. M.; Costantino, R. F.; Dennis, B.; Desharnais, R. A.

    1998-01-01

    Oscillatory populations may exhibit a phase change in which, for example, a high–low periodic pattern switches to a low–high pattern. We propose that phase shifts correspond to stochastic jumps between basins of attraction in an appropriate phase space which associates the different phases of a periodic cycle with distinct attractors. This mechanism accounts for two-cycle phase shifts and the occurrence of asynchronous replicates in experimental cultures of Tribolium.

  11. Fish populations surviving estrogen pollution.

    PubMed

    Wedekind, Claus

    2014-02-10

    Among the most common pollutants that enter the environment after passing municipal wastewater treatment are estrogens, especially the synthetic 17α-ethinylestradiol that is used in oral contraceptives. Estrogens are potent endocrine disruptors at concentrations frequently observed in surface waters. However, new genetic analyses suggest that some fish populations can be self-sustaining even in heavily polluted waters. We now need to understand the basis of this tolerance.

  12. 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

  13. 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.

  14. Food cravings among Brazilian population.

    PubMed

    Queiroz de Medeiros, Anna Cecília; Pedrosa, Lucia de Fatima Campos; Yamamoto, Maria Emilia

    2017-01-01

    This study aimed to develop and validate a Brazilian version of the Food Craving Inventory (FCI-Br), adapted to the cultural-gastronomic context of Brazil, and to explore this behavior among adult Brazilians. The Study 1 population consisted of 453 adults from all regions of Brazil. Participants responded to a preliminary form of the instrument online. Exploratory factor analysis revealed an FCI-Br presenting 23 items and three factors: High Fat, Sweet Food and Traditional Meal. The FCI-Br overall reliability was considered adequate (α = 0.82), as were each of the sub-scales. The food items receiving higher average scores from the application of the instrument were chocolate (3.14 ± 1.28; women) and bread (2.94 ± 1.44, men). A significant association was observed between the specific-craving for Sweet Food and female respondents. Most participants reported experiencing more frequent episodes of food craving when alone (68.0%; n = 391) and during the afternoon (32.2%; n = 127) or evening (43.8%; n = 173) hours. Application of the FCI-Br in a population of 649 university students (Study 2) demonstrated a good adjustment of the model developed according to the Confirmatory factor analysis (χ(2)/gl = 2.82, CFI = 0.94; TLI = 0.93; RMSEA = 0.06). The current findings indicate that the FCI-Br has adequate psychometric properties to measure craving behavior with respect to specific food groups in the resident population of Brazil. The results of this study also shed light on the importance of considering the cultural diversity of a population when investigating eating behaviors.

  15. [The population questions in Rumania].

    PubMed

    Birzea, C

    1993-03-01

    Several months after Romania's dictator, Ceausescu, came to power in 1966, he made abortion the sole method of fertility control, illegal. Births grew in Romania 200% between enactment of this law and 1967. Some other pronatalist actions included taxes on singles and childless couples, assistance to families with many children, discouragement of divorces, and required gynecological exams at large women collectives (e.g. schools and businesses). The population adapted every quickly to these coercive pronatalist measures, however. By 1970, fertility fell steadily. By 1985, it was at the same level as it was pre-Ceausescu (1965). After Ceausescu's fall, repeal of the antiabortion law was one of the first actions taken by the new government, resulting in a 10-fold increase in legal abortions after several months. It also introduced free contraceptive methods which were not available during the Ceausescu years, e.g.. oral contraceptives. This new situation placed the responsibility to make decisions about procreation on people's shoulders. The government chose a population education strategy that emphasizes couples' responsibilities towards upcoming generations and towards improvement of the quality of life. Thus, education networks concerning family life and population grew, principally in 1991. The government created most family life and population education programs in schools, public health institutions and social service agencies, particularly those in large cities. It also called for the media and nongovernmental organizations to also promote programs which encourage parental responsibility, raise the demographic conscience of each person, and explain the moral, social, and economic context of fertility decisions. These education programs have replaced political indoctrination programs and have been integrated into a variety of disciplines. They stress prevention education, including sexual health, prevention of AIDS, drug and alcohol abuse, environmental

  16. 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.

  17. Stellar Population Gradients in WLM

    NASA Astrophysics Data System (ADS)

    Noriega-Mendoza, H.; Holtzman, J.

    2001-12-01

    WLM is one of the most isolated galaxies in the Local Group. From archival HST frames, we look for population gradients using star count ratios from distinct regions of the Color-Magnitude diagram. We find clear evidence for a central concentration of the younger stars. This scenario supports the two-component disk/halo-like structure suggested for dwarf irregular galaxies (Martinez-Delgado, Gallart & Aparicio, 1999).

  18. 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.

  19. Population growth and global warming.

    PubMed

    Short, R V

    2009-01-01

    When I was born in 1930, the human population of the world was a mere 2 billion. Today, it has already reached 6.8 billion, and is projected to reach 9.1 billion by 2050. That is unsustainable. It is slowly beginning to dawn on us that Global Warming is the result of increasing human CO2 emissions, and the more people there are in the world, the worse it will become. Ultimately, it is the sky that will prove to be the limit to our numbers. The developed countries of the world are the most affluent, and also the most effluent, so we must lead by example and contain our own population growth and per capita emissions. We also have a big debt to repay to former colonial territories in Africa, Asia and South America, who desperately need our help to contain their excessive rates of population growth. Belgian and Dutch obstetricians and gynaecologists can play a critical role in this endeavour. After all, we already have a pill that will stop global warming - the oral contraceptive pill.

  20. Simulating Heterogeneous Tumor Cell Populations

    PubMed Central

    Bar-Sagi, Dafna; Mishra, Bud

    2016-01-01

    Certain tumor phenomena, like metabolic heterogeneity and local stable regions of chronic hypoxia, signify a tumor’s resistance to therapy. Although recent research has shed light on the intracellular mechanisms of cancer metabolic reprogramming, little is known about how tumors become metabolically heterogeneous or chronically hypoxic, namely the initial conditions and spatiotemporal dynamics that drive these cell population conditions. To study these aspects, we developed a minimal, spatially-resolved simulation framework for modeling tissue-scale mixed populations of cells based on diffusible particles the cells consume and release, the concentrations of which determine their behavior in arbitrarily complex ways, and on stochastic reproduction. We simulate cell populations that self-sort to facilitate metabolic symbiosis, that grow according to tumor-stroma signaling patterns, and that give rise to stable local regions of chronic hypoxia near blood vessels. We raise two novel questions in the context of these results: (1) How will two metabolically symbiotic cell subpopulations self-sort in the presence of glucose, oxygen, and lactate gradients? We observe a robust pattern of alternating striations. (2) What is the proper time scale to observe stable local regions of chronic hypoxia? We observe the stability is a function of the balance of three factors related to O2—diffusion rate, local vessel release rate, and viable and hypoxic tumor cell consumption rate. We anticipate our simulation framework will help researchers design better experiments and generate novel hypotheses to better understand dynamic, emergent whole-tumor behavior. PMID:28030620