WorldWideScience

Sample records for experimental plant population

  1. Influence of Multiple Infection and Relatedness on Virulence: Disease Dynamics in an Experimental Plant Population and Its Castrating Parasite

    Science.gov (United States)

    Buono, Lorenza; López-Villavicencio, Manuela; Shykoff, Jacqui A.; Snirc, Alodie; Giraud, Tatiana

    2014-01-01

    The level of parasite virulence, i.e., the decrease in host's fitness due to a pathogen, is expected to depend on several parameters, such as the type of the disease (e.g., castrating or host-killing) and the prevalence of multiple infections. Although these parameters have been extensively studied theoretically, few empirical data are available to validate theoretical predictions. Using the anther smut castrating disease on Silene latifolia caused by Microbotryum lychnidis-dioicae, we studied the dynamics of multiple infections and of different components of virulence (host death, non-recovery and percentage of castrated stems) during the entire lifespan of the host in an experimental population. We monitored the number of fungal genotypes within plants and their relatedness across five years, using microsatellite markers, as well as the rates of recovery and host death in the population. The mean relatedness among genotypes within plants remained at a high level throughout the entire host lifespan despite the dynamics of the disease, with recurrent new infections. Recovery was lower for plants with multiple infections compared to plants infected by a single genotype. As expected for castrating parasites, M. lychnidis-dioicae did not increase host mortality. Mortality varied across years but was generally lower for plants that had been diseased the preceding year. This is one of the few studies to have empirically verified theoretical expectations for castrating parasites, and to show particularly i) that castrated hosts live longer, suggesting that parasites can redirect resources normally used in reproduction to increase host lifespan, lengthening their transmission phase, and ii) that multiple infections increase virulence, here in terms of non-recovery and host castration. PMID:24892951

  2. Populations in clonal plants

    Directory of Open Access Journals (Sweden)

    Jussi Tammisola

    1986-12-01

    Full Text Available Population phenomena in higher plants are reviewed critically, particularly in relation to clonality. An array of concepts used in the field are discussed. In contrast to animals, higher plants are modular in structure. Plant populations show hierarchy at two levels: ramets and genets. In addition, their demography is far more complicated, since even the direction of development of a ramet may change by rejuvenation. Therefore, formulae concerning animal populations often require modification for plants. Furthermore, at the zygotic stage, higher plants are generally less mobile than animals. Accordingly, their population processes tend to be more local. Most populations of plants have a genetic structure: alleles and genotypes are spatially aggregated. Due to the short-ranged foraging behaviour of pollinators, genetically non-random pollination prevails. A generalized formula for parent-offspring dispersal variance is derived. It is used to analyze the effect of clonality on genetic patchiness in populations. In self-compatible species, an increase in clonality will tend to increase the degree of patchiness, while in self-incompatible species a decrease may result. Examples of population structure studies in different species are presented. A considerable degree of genetic variation appears to be found also in the populations of species with a strong allocation of resources to clonal growth or apomictic seed production. Some consequences of clonality are considered from the point of view of genetic conservation and plant breeding.

  3. RELATIONSHIPS BETWEEN PLANT-DENSITY, OUTCROSSING RATES AND SEED SET IN NATURAL AND EXPERIMENTAL POPULATIONS OF SCABIOSA-COLUMBARIA

    NARCIS (Netherlands)

    VANTREUREN, R; BIJLSMA, R; OUBORG, NJ; KWAK, MM

    Outcrossing rates were estimated in both natural and experimental populations of Scabiosa columbaria, a self-compatible, entomophilous, gynodioecious, protandrous perennial. In natural populations, estimates of the outcrossing rate in hermaphrodites were near to one and ranged from 0.84 +/- 0.07 to

  4. Process Experimental Pilot Plant

    International Nuclear Information System (INIS)

    Henze, H.

    1986-01-01

    The Process Experimental Pilot Plant (PREPP) at the Idaho National Engineering Laboratory (INEL) was built to convert transuranic contaminated solid waste into a form acceptable for disposal at the Waste Isolation Pilot Plant (WIPP), located near Carlsbad, New Mexico. There are about 2.0 million cubic ft of transuranic waste stored at the Transuranic Storage Area of the INEL's Radioactive Waste Management Complex (RWMC). The Stored Waste Examination Pilot Plant (SWEPP) located at the RWMC will examine this stored transuranic waste to determine if the waste is acceptable for direct shipment to and storage at WIPP, or if it requires shipment to PREPP for processing before shipment to WIPP. The PREPP process shreds the waste, incinerates the shredded waste, and cements (grouts) the shredded incinerated waste in new 55-gal drums. Unshreddable items are repackaged and returned to SWEPP. The process off-gas is cleaned prior to its discharge to the atmosphere, and complies with the effluent standards of the State of Idaho, EPA, and DOE. Waste liquid generated is used in the grouting operation

  5. Experimental mutagenesis in plants

    International Nuclear Information System (INIS)

    Conger, B.V.

    1979-01-01

    Considerable progress has been made in directed or controlled mutagenesis with bacterial systems, the genetic resolving power of which is much greater than that of higher plants. The mutagen specificity in higher plants has been of great interest, and numerous results and observations have been reported. The advances in the culture of plant cells and tissues have created much interest concerning the possibility of inducing and recovering mutants at the cellular level. There are great problems including the failure to regenerate plants from cells in all but a few species. The genetic and cytogenetic instability in the culture of plant tissues is well known, and the most common nuclear change is polyploidy including aneuploidy. The degree of polyploidy increases with calluses or culture age. In rice, the frequency of aneuploidy is greater in the calluses derived from roots than those derived from stem internodes. Polyploid and/or self-incompatible plant species are not as amenable to conventional mutation breeding techniques as diploid, self-fertilizing species. Inducing mutations in somatic tissues creates the problem of chimeras. However, the new cultivars of highly heterozygous, outcrossing, self-incompatible species are produced by combining several different clones. The performance of the progeny of at least 4 generations removed from the polycross of the parent clones is the important factor, and a high amount of heterozygocity is tolerated within cultivars and even on the same plants. (Yamashita, S.)

  6. Genome scans on experimentally evolved populations reveal candidate regions for adaptation to plant resistance in the potato cyst nematode Globodera pallida.

    Science.gov (United States)

    Eoche-Bosy, D; Gautier, M; Esquibet, M; Legeai, F; Bretaudeau, A; Bouchez, O; Fournet, S; Grenier, E; Montarry, J

    2017-09-01

    Improving resistance durability involves to be able to predict the adaptation speed of pathogen populations. Identifying the genetic bases of pathogen adaptation to plant resistances is a useful step to better understand and anticipate this phenomenon. Globodera pallida is a major pest of potato crop for which a resistance QTL, GpaV vrn , has been identified in Solanum vernei. However, its durability is threatened as G. pallida populations are able to adapt to the resistance in few generations. The aim of this study was to investigate the genomic regions involved in the resistance breakdown by coupling experimental evolution and high-density genome scan. We performed a whole-genome resequencing of pools of individuals (Pool-Seq) belonging to G. pallida lineages derived from two independent populations having experimentally evolved on susceptible and resistant potato cultivars. About 1.6 million SNPs were used to perform the genome scan using a recent model testing for adaptive differentiation and association to population-specific covariables. We identified 275 outliers and 31 of them, which also showed a significant reduction in diversity in adapted lineages, were investigated for their genic environment. Some candidate genomic regions contained genes putatively encoding effectors and were enriched in SPRYSECs, known in cyst nematodes to be involved in pathogenicity and in (a)virulence. Validated candidate SNPs will provide a useful molecular tool to follow frequencies of virulence alleles in natural G. pallida populations and define efficient strategies of use of potato resistances maximizing their durability. © 2017 John Wiley & Sons Ltd.

  7. Experimental evolution in biofilm populations

    Science.gov (United States)

    Steenackers, Hans P.; Parijs, Ilse; Foster, Kevin R.; Vanderleyden, Jozef

    2016-01-01

    Biofilms are a major form of microbial life in which cells form dense surface associated communities that can persist for many generations. The long-life of biofilm communities means that they can be strongly shaped by evolutionary processes. Here, we review the experimental study of evolution in biofilm communities. We first provide an overview of the different experimental models used to study biofilm evolution and their associated advantages and disadvantages. We then illustrate the vast amount of diversification observed during biofilm evolution, and we discuss (i) potential ecological and evolutionary processes behind the observed diversification, (ii) recent insights into the genetics of adaptive diversification, (iii) the striking degree of parallelism between evolution experiments and real-life biofilms and (iv) potential consequences of diversification. In the second part, we discuss the insights provided by evolution experiments in how biofilm growth and structure can promote cooperative phenotypes. Overall, our analysis points to an important role of biofilm diversification and cooperation in bacterial survival and productivity. Deeper understanding of both processes is of key importance to design improved antimicrobial strategies and diagnostic techniques. PMID:26895713

  8. Nuclear power plants in populated areas

    International Nuclear Information System (INIS)

    Wachsmann, F.

    1973-01-01

    The article first deals with the permanently increasing demand for electical power. Considering the ever growing energy demand which can no longer be covered by conventional power plants, it has become necessary to set up nuclear power plants of larger range. The author presents in a survey the basic function of nuclear power plants as well as the resulting risks and safety measures. The author concludes that according to present knowledge there is no more need to erect nuclear power plants outside densely populated urban areas but there is now the possibility of erecting nuclear power plants in densely populated areas. (orig./LH) [de

  9. Soil - plant experimental radionuclide transfer factors

    International Nuclear Information System (INIS)

    Dobrin, R.I.; Dulama, C.N.; Toma, Al.

    2006-01-01

    Some experimental research was performed in our institute to assess site specific soil-plant transfer factors. A full characterization of an experimental site was done both from pedo-chemical and radiological point of view. Afterwards, a certain number of culture plants were grown on this site and the evolution of their radionuclide burden was then recorded. Using some soil amendments one performed a parallel experiment and the radionuclide root uptake was evaluated and recorded. Hence, transfer parameters were calculated and some conclusions were drawn concerning the influence of site specific conditions on the root uptake of radionuclides. (authors)

  10. Experimental plant for sludge composting. Plant experimental de compostaje de lodos

    Energy Technology Data Exchange (ETDEWEB)

    Cadenas, A.; Caellas, N.; Amengual, A.; Calafact, J.

    1993-01-01

    Results and expertise collected during the first year of exploitation of a compost experimental plant located in Mallorca (Spain): The plant is treating sludge from the biological treatment plant of water at the town of Felanitx and the compost produced is used in agriculture. (Author)

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

    Science.gov (United States)

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

    2012-01-01

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

  12. The effect of plant population and nitrogen fertilizer on

    Directory of Open Access Journals (Sweden)

    mohamad reza asgaripor

    2009-06-01

    Full Text Available Interest has increased towards hemp (Cannabis sativa L. fibre production due to renewed demand for natural fibre in the world. A Study was conducted in 2005 at Shirvan in Northern Khorasan province, Iran, to determine the effects of three plant populations (30, 90 and 150 plant per m2 and three rates of nitrogen application (50, 150 and 250 kg N per ha on final stand, stalk height, basal stalk diameter, total stalk yield as well as fibre content from stalk and fibre yield in male and female plants. A split plot experimental with three replications was used. The result indicated that due to enhanced competition for light at higher population on density and N2 level plant mortality was higher than other treatment Morphological characteristics were highly correlated with plant sexual, plant population and nitrogen fertilizer. Highest stem, leaf and inflorescence yield were obtained at 250 plant m-2 when 150 kg N ha-1 was used. Lowest plant density did not show self-thinning but reduced above ground dry matter. Shoot dry matter increased with increasing plant density and nitrogen supply. Apparently, fibre content was greater at medium density and lowest nitrogen fertilizer, however, fibre yield was greatest at highest plant population and nitrogen fertilizer. In terms of fibre yield, approximate 31.7% of the fibre was located in the bottom parts, 22.4% in the middle and only 9.9% in the top part of the stem. The results suggest that hemp can yield large quantities of useful fibre at Shirvan when planted in proper plant densities and suitable nitrogen fertilizer.

  13. Host plant adaptation in Drosophila mettleri populations.

    Directory of Open Access Journals (Sweden)

    Sergio Castrezana

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

  14. Population trends around nuclear power plants

    International Nuclear Information System (INIS)

    Greenberg, M.; Krueckeberg, D.A.; Kaltman, M.

    1984-01-01

    Site selection criteria used by the Nuclear Regulatory Commission emphasize the selection of low population areas in which little growth is anticipated. This research examines population growth after site selection for the period 1960 to 1980 for forty-three operating sites. Substantial increments of population increase were found, only partially explained by national, regional, and host county growth trends impacting local host areas. These local components of change became especially important in the decade of the 1970s, when most of the plants were in full operation. The decade of the 1970s also saw a marked shift from the geographic pattern of growth of the 60s, when few plants were in operation. These larger and different growth components of the 1970s, also unexplained by preliminary analysis of correlation with coastal locations and degree of urbanization, are classified into categories with high potential and interest for further research

  15. Individualism in plant populations: using stochastic differential equations to model individual neighbourhood-dependent plant growth.

    Science.gov (United States)

    Lv, Qiming; Schneider, Manuel K; Pitchford, Jonathan W

    2008-08-01

    We study individual plant growth and size hierarchy formation in an experimental population of Arabidopsis thaliana, within an integrated analysis that explicitly accounts for size-dependent growth, size- and space-dependent competition, and environmental stochasticity. It is shown that a Gompertz-type stochastic differential equation (SDE) model, involving asymmetric competition kernels and a stochastic term which decreases with the logarithm of plant weight, efficiently describes individual plant growth, competition, and variability in the studied population. The model is evaluated within a Bayesian framework and compared to its deterministic counterpart, and to several simplified stochastic models, using distributional validation. We show that stochasticity is an important determinant of size hierarchy and that SDE models outperform the deterministic model if and only if structural components of competition (asymmetry; size- and space-dependence) are accounted for. Implications of these results are discussed in the context of plant ecology and in more general modelling situations.

  16. Tools for Genetic Studies in Experimental Populations of Polyploids

    Directory of Open Access Journals (Sweden)

    Peter M. Bourke

    2018-04-01

    Full Text Available Polyploid organisms carry more than two copies of each chromosome, a condition rarely tolerated in animals but which occurs relatively frequently in the plant kingdom. One of the principal challenges faced by polyploid organisms is to evolve stable meiotic mechanisms to faithfully transmit genetic information to the next generation upon which the study of inheritance is based. In this review we look at the tools available to the research community to better understand polyploid inheritance, many of which have only recently been developed. Most of these tools are intended for experimental populations (rather than natural populations, facilitating genomics-assisted crop improvement and plant breeding. This is hardly surprising given that a large proportion of domesticated plant species are polyploid. We focus on three main areas: (1 polyploid genotyping; (2 genetic and physical mapping; and (3 quantitative trait analysis and genomic selection. We also briefly review some miscellaneous topics such as the mode of inheritance and the availability of polyploid simulation software. The current polyploid analytic toolbox includes software for assigning marker genotypes (and in particular, estimating the dosage of marker alleles in the heterozygous condition, establishing chromosome-scale linkage phase among marker alleles, constructing (short-range haplotypes, generating linkage maps, performing genome-wide association studies (GWAS and quantitative trait locus (QTL analyses, and simulating polyploid populations. These tools can also help elucidate the mode of inheritance (disomic, polysomic or a mixture of both as in segmental allopolyploids or reveal whether double reduction and multivalent chromosomal pairing occur. An increasing number of polyploids (or associated diploids are being sequenced, leading to publicly available reference genome assemblies. Much work remains in order to keep pace with developments in genomic technologies. However, such

  17. Tools for Genetic Studies in Experimental Populations of Polyploids.

    Science.gov (United States)

    Bourke, Peter M; Voorrips, Roeland E; Visser, Richard G F; Maliepaard, Chris

    2018-01-01

    Polyploid organisms carry more than two copies of each chromosome, a condition rarely tolerated in animals but which occurs relatively frequently in the plant kingdom. One of the principal challenges faced by polyploid organisms is to evolve stable meiotic mechanisms to faithfully transmit genetic information to the next generation upon which the study of inheritance is based. In this review we look at the tools available to the research community to better understand polyploid inheritance, many of which have only recently been developed. Most of these tools are intended for experimental populations (rather than natural populations), facilitating genomics-assisted crop improvement and plant breeding. This is hardly surprising given that a large proportion of domesticated plant species are polyploid. We focus on three main areas: (1) polyploid genotyping; (2) genetic and physical mapping; and (3) quantitative trait analysis and genomic selection. We also briefly review some miscellaneous topics such as the mode of inheritance and the availability of polyploid simulation software. The current polyploid analytic toolbox includes software for assigning marker genotypes (and in particular, estimating the dosage of marker alleles in the heterozygous condition), establishing chromosome-scale linkage phase among marker alleles, constructing (short-range) haplotypes, generating linkage maps, performing genome-wide association studies (GWAS) and quantitative trait locus (QTL) analyses, and simulating polyploid populations. These tools can also help elucidate the mode of inheritance (disomic, polysomic or a mixture of both as in segmental allopolyploids) or reveal whether double reduction and multivalent chromosomal pairing occur. An increasing number of polyploids (or associated diploids) are being sequenced, leading to publicly available reference genome assemblies. Much work remains in order to keep pace with developments in genomic technologies. However, such technologies

  18. DISEÑO CONCEPTUAL DE UNA ESTACIÓN EXPERIMENTAL DE TRATAMIENTO DE AGUAS RESIDUALES DOMÉSTICAS ORIENTADA A MUNICIPIOS CON POBLACIÓN MENOR A 30.000 HABITANTES CONCEPTUAL DESIGN OF AN EXPERIMENTAL HOUSEHOLD WASTE WATER TREATMENT PLANT ADDRESSED TO MUNICIPALITIES WITH A POPULATION LOWER THAN 30,000 INHABITANTS

    Directory of Open Access Journals (Sweden)

    José Luis González Manosalva

    2012-12-01

    Full Text Available Se presenta el diseño conceptual de una planta experimental de tratamiento de aguas residuales para poblaciones menores de 30.000 habitantes. El diseño integra seis esquemas de tratamiento interconectados, incluyendo sistemas convencionales y no convencionales, con disposición final del efluente a un cuerpo de agua o infiltración lenta en el terreno, cumpliendo con la norma vigente en Colombia. El proceso incluyó una revisión del estado del arte, el diseño de plantas de este tipo como la planta de Carrión de los Céspedes (Andalucía-España, la planta UFMG/COPASA (Minas Gerais-Brasil, los trabajos realizados en Colombia del IDEAM-CINARA-UTP y los ensayos realizados por Madera, Silva y Peña del CINARA en planta piloto. El área estimada para la construcción de los esquemas propuestos es de 18.000 m² y los costos fijos de construcción de la planta se estiman en 850 millones de pesos para tratar un caudal de 1,5 l/s de agua residual doméstica.Conceptual design of an experimental waste water treatment plant for populations lower than 30,000 inhabitants is presented. The design integrates six interconnected treatment systems, including conventional and non-conventional systems with final disposal of the effluent to a water body or slow infiltration in the soil, complying with Colombian norms in force. The process included a state-of-the-art revision, design of this kind of plants (such as Carrión de los Céspedes in Andalucía, Spain; UFMG/COPASA plant in Minas Gerais-Brazil, works conducted in Colombia (IDEAM-CINARA-UTP, and tests performed by Madera, Silva, and Peña from CINARA in a pilot plant. Area estimated for construction of systems proposed reaches 18,000 m² and fixed costs for construction of the plant is estimated in 850 million Colombian pesos for treating a 1.5 l/s flow of household waste water.

  19. Experimental infection of plants with an herbivore-associated bacterial endosymbiont influences herbivore host selection behavior.

    Directory of Open Access Journals (Sweden)

    Thomas Seth Davis

    Full Text Available Although bacterial endosymbioses are common among phloeophagous herbivores, little is known regarding the effects of symbionts on herbivore host selection and population dynamics. We tested the hypothesis that plant selection and reproductive performance by a phloem-feeding herbivore (potato psyllid, Bactericera cockerelli is mediated by infection of plants with a bacterial endosymbiont. We controlled for the effects of herbivory and endosymbiont infection by exposing potato plants (Solanum tuberosum to psyllids infected with "Candidatus Liberibacter solanacearum" or to uninfected psyllids. We used these treatments as a basis to experimentally test plant volatile emissions, herbivore settling and oviposition preferences, and herbivore population growth. Three important findings emerged: (1 plant volatile profiles differed with respect to both herbivory and herbivory plus endosymbiont infection when compared to undamaged control plants; (2 herbivores initially settled on plants exposed to endosymbiont-infected psyllids but later defected and oviposited primarily on plants exposed only to uninfected psyllids; and (3 plant infection status had little effect on herbivore reproduction, though plant flowering was associated with a 39% reduction in herbivore density on average. Our experiments support the hypothesis that plant infection with endosymbionts alters plant volatile profiles, and infected plants initially recruited herbivores but later repelled them. Also, our findings suggest that the endosymbiont may not place negative selection pressure on its host herbivore in this system, but plant flowering phenology appears correlated with psyllid population performance.

  20. 27 CFR 19.65 - Experimental distilled spirits plants.

    Science.gov (United States)

    2010-04-01

    ... spirits plants. 19.65 Section 19.65 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS DISTILLED SPIRITS PLANTS Administrative and Miscellaneous Provisions Activities Not Subject to This Part § 19.65 Experimental distilled spirits plants. The...

  1. Experimental demonstration of an Allee effect in microbial populations

    OpenAIRE

    Kaul, RajReni B.; Kramer, Andrew M.; Dobbs, Fred C.; Drake, John M.

    2016-01-01

    Microbial populations can be dispersal limited. However, microorganisms that successfully disperse into physiologically ideal environments are not guaranteed to establish. This observation contradicts the Baas-Becking tenet: ?Everything is everywhere, but the environment selects?. Allee effects, which manifest in the relationship between initial population density and probability of establishment, could explain this observation. Here, we experimentally demonstrate that small populations of Vi...

  2. Ecological and population genetics of locally rare plants: A review

    Science.gov (United States)

    Simon A. Lei

    2001-01-01

    Plant species with limited dispersal ability, narrow geographical and physiological tolerance ranges, as well as with specific habitat and ecological requirements are likely to be rare. Small and isolated populations and species contain low levels of within-population genetic variation in many plant species. The gene pool of plants is a product of phenotype-environment...

  3. Effect of plant population and N fertilizer on the growth and yield of ...

    African Journals Online (AJOL)

    Responses of bambara groundnut (Vigna subterranea (L.) Verdc) to 3 levels of fertilizer N (0, 50, and 100 kg N/ha) and seven plant populations (55555, 63492, 74074, 88888, 111111, 148148 and 222222 plants/ha) were studied under field conditions in Nsukka, Nigeria. The experimental design was a randomized ...

  4. Nitrogen rate and plant population effects on yield and yield ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-17

    Dec 17, 2008 ... density and nitrogen rate increased plant height, lowest pod height, harvest index and seed yield. ... since some combine harvester heads are unable to pick ..... as effected by population density and plant distribution.

  5. Improving plant bioaccumulation science through consistent reporting of experimental data

    DEFF Research Database (Denmark)

    Fantke, Peter; Arnot, Jon A.; Doucette, William J.

    2016-01-01

    Experimental data and models for plant bioaccumulation of organic contaminants play a crucial role for assessing the potential human and ecological risks associated with chemical use. Plants are receptor organisms and direct or indirect vectors for chemical exposures to all other organisms. As new...... experimental data are generated they are used to improve our understanding of plant-chemical interactions that in turn allows for the development of better scientific knowledge and conceptual and predictive models. The interrelationship between experimental data and model development is an ongoing, never......-ending process needed to advance our ability to provide reliable quality information that can be used in various contexts including regulatory risk assessment. However, relatively few standard experimental protocols for generating plant bioaccumulation data are currently available and because of inconsistent...

  6. The plant microbiome explored: implications for experimental botany

    Energy Technology Data Exchange (ETDEWEB)

    Berg, Gabriele; Rybakova, Daria; Grube, Martin; Köberl, Martina

    2015-11-07

    The importance of microbial root inhabitants for plant growth and health was recognized as early as 100 years ago. Recent insights reveal a close symbiotic relationship between plants and their associated microorganisms, and high structural and functional diversity within plant microbiomes. Plants provide microbial communities with specific habitats, which can be broadly categorized as the rhizosphere, phyllosphere, and endosphere. Plant-associated microbes interact with their host in essential functional contexts. They can stimulate germination and growth, help plants fend off disease, promote stress resistance, and influence plant fitness. Therefore, plants have to be considered as metaorganisms within which the associated microbes usually outnumber the cells belonging to the plant host. The structure of the plant microbiome is determined by biotic and abiotic factors but follows ecological rules. Metaorganisms are coevolved species assemblages. The metabolism and morphology of plants and their microbiota are intensively connected with each other, and the interplay of both maintains the functioning and fitness of the holobiont. Our study of the current literature shows that analysis of plant microbiome data has brought about a paradigm shift in our understanding of the diverse structure and functioning of the plant microbiome with respect to the following: (i) the high interplay of bacteria, archaea, fungi, and protists; (ii) the high specificity even at cultivar level; (iii) the vertical transmission of core microbiomes; (iv) the extraordinary function of endophytes; and (v) several unexpected functions and metabolic interactions. The plant microbiome should be recognized as an additional factor in experimental botany and breeding strategies.

  7. The plant microbiome explored: implications for experimental botany.

    Science.gov (United States)

    Berg, Gabriele; Rybakova, Daria; Grube, Martin; Köberl, Martina

    2016-02-01

    The importance of microbial root inhabitants for plant growth and health was recognized as early as 100 years ago. Recent insights reveal a close symbiotic relationship between plants and their associated microorganisms, and high structural and functional diversity within plant microbiomes. Plants provide microbial communities with specific habitats, which can be broadly categorized as the rhizosphere, phyllosphere, and endosphere. Plant-associated microbes interact with their host in essential functional contexts. They can stimulate germination and growth, help plants fend off disease, promote stress resistance, and influence plant fitness. Therefore, plants have to be considered as metaorganisms within which the associated microbes usually outnumber the cells belonging to the plant host. The structure of the plant microbiome is determined by biotic and abiotic factors but follows ecological rules. Metaorganisms are co-evolved species assemblages. The metabolism and morphology of plants and their microbiota are intensively connected with each other, and the interplay of both maintains the functioning and fitness of the holobiont. Our study of the current literature shows that analysis of plant microbiome data has brought about a paradigm shift in our understanding of the diverse structure and functioning of the plant microbiome with respect to the following: (i) the high interplay of bacteria, archaea, fungi, and protists; (ii) the high specificity even at cultivar level; (iii) the vertical transmission of core microbiomes; (iv) the extraordinary function of endophytes; and (v) several unexpected functions and metabolic interactions. The plant microbiome should be recognized as an additional factor in experimental botany and breeding strategies. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  8. Analysis of biogas transformation in experimental biogas plant

    Directory of Open Access Journals (Sweden)

    Eva Jelínková

    2011-01-01

    Full Text Available The topic of this paper is the analysis of anaerobic fermentation in an experimental biogas plant. Technological processes and operation parameters were monitored; these processes and parameters include, for example, the optimal structure of the input material and the consideration of the prolonging of the duration of the fermentation process. The goal of prolonging the fermentation process is to obtain higher biogas (and methane production and to decrease the fermentation residue effluvial emissions. Emphasis is also laid on the mutual co-fermentation of substrates with regard to further use of the results in solving technological problems in other biogas plants. This technological process was first monitored in 2009; that is, before the planned intensification and modernization of the experimental biogas plant. Thus, the evaluation of the process could become part of the planned intensification and modernization of the chosen biogas plant (extended by the addition of the second stage of methanogenesis. The results obtained from the experimental biogas plant, which is one of the pioneering biogas plants in the Czech Republic, may serve, to other biogas operators, as a base for the preparation of suitable input, and for improving the efficiency of anaerobic fermentation within their biogas plants. The goal of the improvement of the fermentation process is to fulfill the ecological aspects; that is, to cut down CO2 emissions and to reduce the negative impact of the fermentation process on the environment (reduction of effluvium and noise originating in biogas plants.

  9. Projecting the success of plant restoration with population viability analysis

    Science.gov (United States)

    Bell, T.J.; Bowles, M.L.; McEachern, A.K.; Brigham, C.A.; Schwartz, M.W.

    2003-01-01

    Conserving viable populations of plant species requires that they have high probabilities of long-term persistence within natural habitats, such as a chance of extinction in 100 years of less than 5% (Menges 1991, 1998; Brown 1994; Pavlik 1994; Chap. 1, this Vol.). For endangered and threatened species that have been severely reduces in range and whose habitats have been fragmented, important species conservation strategies may include augmenting existing populations or restoring new viable populations (Bowles and Whelan 1994; Chap. 2, this Vol.). Restoration objectives may include increasing population numbers to reduce extinction probability, deterministic manipulations to develop a staged cohort structure, or more complex restoration of a desired genetic structure to allow outcrossing or increase effective population size (DeMauro 1993, 1994; Bowles et al. 1993, 1998; Pavlik 1994; Knapp and Dyer 1998; Chap. 2, this Vol.). These efforts may require translocation of propagules from existing (in situ) populations, or from ex situ botanic gardens or seed storage facilities (Falk et al. 1996; Guerrant and Pavlik 1998; Chap. 2, this Vol.). Population viability analysis (PVA) can provide a critical foundation for plant restoration, as it models demographic projections used to evaluate the probability of population persistence and links plant life history with restoration strategies. It is unknown how well artificially created populations will meet demographic modeling requirements (e.g., due to artificial cohort transitions) and few, if any, PVAs have been applied to restorations. To guide application of PVA to restored populations and to illustrate potential difficulties, we examine effects of planting different life stages, model initial population sizes needed to achieve population viability, and compare demographic characteristics between natural and restored populations. We develop and compare plant population restoration viability analysis (PRVA) case studies of

  10. Investigations for decision making on an old tailing pond of a former experimental metallurgical plant

    International Nuclear Information System (INIS)

    Razikov, Z.A.; Pavljuk, L.M.; Bezzubov, N.I.

    2002-01-01

    Investigations are described on an abandoned tailing pond of a former experimental metallurgical plant which operated during the period 1945-1950. The aim of these investigations was to explore radiological hazards arising from the tailing pond for the population and to obtain data for decision making on redeployment or dumping of the pond. Methods used, results obtained and conclusions drawn are outlined. (author)

  11. Improving plant bioaccumulation science through consistent reporting of experimental data.

    Science.gov (United States)

    Fantke, Peter; Arnot, Jon A; Doucette, William J

    2016-10-01

    Experimental data and models for plant bioaccumulation of organic contaminants play a crucial role for assessing the potential human and ecological risks associated with chemical use. Plants are receptor organisms and direct or indirect vectors for chemical exposures to all other organisms. As new experimental data are generated they are used to improve our understanding of plant-chemical interactions that in turn allows for the development of better scientific knowledge and conceptual and predictive models. The interrelationship between experimental data and model development is an ongoing, never-ending process needed to advance our ability to provide reliable quality information that can be used in various contexts including regulatory risk assessment. However, relatively few standard experimental protocols for generating plant bioaccumulation data are currently available and because of inconsistent data collection and reporting requirements, the information generated is often less useful than it could be for direct applications in chemical assessments and for model development and refinement. We review existing testing guidelines, common data reporting practices, and provide recommendations for revising testing guidelines and reporting requirements to improve bioaccumulation knowledge and models. This analysis provides a list of experimental parameters that will help to develop high quality datasets and support modeling tools for assessing bioaccumulation of organic chemicals in plants and ultimately addressing uncertainty in ecological and human health risk assessments. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Plant experience of experimental fast reactor 'Joyo'

    International Nuclear Information System (INIS)

    1982-01-01

    The experimental fast reactor ''JOYO'' installed in Power Reactor and Nuclear Fuel Development Corp. (PNC) of Japan completed its operation using the first core (called MK-I core) in December, 1981, and the works to transfer to MK-2 core have been performed since January, 1982. In this report, the experiences obtained through the construction, test and operation of ''JOYO'' over 12 years from the start of erection in 1970 to the termination of operation in 1981 are described. The contents of the report are divided into design, construction, the outline of facilities, testing, operating and maintenance experiences, and the topics on MK-I operation. As for the construction, the design changes performed before the start of manufacture or construction and the improvement and trouble restoring works implemented at the start of overall functional tests are reported. As for testing, overall functional tests, criticality test, low power test and power increasing test are described in detail. The number of test items of overall functional testing reached 266. The rated output operation of the reactor at 75 MW was performed six times in 1980 and 1981 until the termination of operation. No fuel failure was detected in MK-I operation, and the stable operation performance of the FBR was proved through MK-I operation. The topics on the MK-I operation includes natural circulation test, the measurement of total leakage rate for the containment vessel, and wear-marks which are the trace of wear due to the contact of fuel pins with the wires wound around the adjacent fuel pins, found in the post irradiation examination of fuel. (Wakatsuki, Y.)

  13. Simplified simulation of an experimental fast reactor plant

    International Nuclear Information System (INIS)

    Fujii, Masaaki; Fujita, Minoru.

    1978-01-01

    Purposes of the simulation are to study the dynamic behavior of a liquid metal-cooled experimental fast breeder reactor plant and to design the control system of the reactor plant by modified-RAPID (Reactor and Plant Integrated Dynamics) computer program. As for the plant model, the Japan Experimental Fast Reactor ''Joyo'' was referred to approximately. This computer program is designed for the calculation of steady-state and transient temperatures in a FBR plant; which is described by a model consisting of the core, upper and lower plenums, an intermediate heat exchanger, an air dump heat exchanger, primary-secondary and tertiary coolant systems and connecting pipes. The basic equations are solved numerically by finite difference approximation. The mathematical model for an experimental FBR plant is useful for the design of the control system of FBR plants. The results of numerical simulation showed that the proportional change in the flow rates of the primary and secondary coolant loops provides good performance in relation to the stepped change in the power level. (J.P.N.)

  14. Population Exposure Estimates in Proximity to Nuclear Power Plants, Locations

    Data.gov (United States)

    National Aeronautics and Space Administration — The Population Exposure Estimates in Proximity to Nuclear Power Plants, Locations data set combines information from a global data set developed by Declan Butler of...

  15. Experimental demonstration of an Allee effect in microbial populations.

    Science.gov (United States)

    Kaul, RajReni B; Kramer, Andrew M; Dobbs, Fred C; Drake, John M

    2016-04-01

    Microbial populations can be dispersal limited. However, microorganisms that successfully disperse into physiologically ideal environments are not guaranteed to establish. This observation contradicts the Baas-Becking tenet: 'Everything is everywhere, but the environment selects'. Allee effects, which manifest in the relationship between initial population density and probability of establishment, could explain this observation. Here, we experimentally demonstrate that small populations of Vibrio fischeri are subject to an intrinsic demographic Allee effect. Populations subjected to predation by the bacterivore Cafeteria roenbergensis display both intrinsic and extrinsic demographic Allee effects. The estimated critical threshold required to escape positive density-dependence is around 5, 20 or 90 cells ml(-1)under conditions of high carbon resources, low carbon resources or low carbon resources with predation, respectively. This work builds on the foundations of modern microbial ecology, demonstrating that mechanisms controlling macroorganisms apply to microorganisms, and provides a statistical method to detect Allee effects in data. © 2016 The Author(s).

  16. Evolution of outcrossing in experimental populations of Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Henrique Teotonio

    Full Text Available Caenorhabditis elegans can reproduce exclusively by self-fertilization. Yet, males can be maintained in laboratory populations, a phenomenon that continues to puzzle biologists. In this study we evaluated the role of males in facilitating adaptation to novel environments. For this, we contrasted the evolution of a fitness component exclusive to outcrossing in experimental populations of different mating systems. We introgressed a modifier of outcrossing into a hybrid population derived from several wild isolates to transform the wild-type androdioecious mating system into a dioecious mating system. By genotyping 375 single-nucleotide polymorphisms we show that the two populations had similar standing genetic diversity available for adaptation, despite the occurrence of selection during their derivation. We then performed replicated experimental evolution under the two mating systems from starting conditions of either high or low levels of diversity, under defined environmental conditions of discrete non-overlapping generations, constant density at high population sizes (N = 10(4, no obvious spatial structure and abundant food resources. During 100 generations measurements of sex ratios and male competitive performance showed: 1 adaptation to the novel environment; 2 directional selection on male frequency under androdioecy; 3 optimal outcrossing rates of 0.5 under androdioecy; 4 the existence of initial inbreeding depression; and finally 5 that the strength of directional selection on male competitive performance does not depend on male frequencies. Taken together, these results suggest that androdioecious males are maintained at intermediate frequencies because outcrossing is adaptive.

  17. An experimental test of alternative population augmentation scenarios.

    Science.gov (United States)

    Kronenberger, John A; Gerberich, Jill C; Fitzpatrick, Sarah W; Broder, E Dale; Angeloni, Lisa M; Funk, W Chris

    2018-01-19

    Human land use is fragmenting habitats worldwide and inhibiting dispersal among previously connected populations of organisms, often leading to inbreeding depression and reduced evolutionary potential in the face of rapid environmental change. To combat this augmentation of isolated populations with immigrants is sometimes used to facilitate demographic and genetic rescue. Augmentation with immigrants that are genetically and adaptively similar to the target population effectively increases population fitness, but if immigrants are very genetically or adaptively divergent, augmentation can lead to outbreeding depression. Despite well-cited guidelines for the best practice selection of immigrant sources, often only highly divergent populations remain, and experimental tests of these riskier augmentation scenarios are essentially nonexistent. We conducted a mesocosm experiment with Trinidadian guppies (Poecilia reticulata) to test the multigenerational demographic and genetic effects of augmenting 2 target populations with 3 types of divergent immigrants. We found no evidence of demographic rescue, but we did observe genetic rescue in one population. Divergent immigrant treatments tended to maintain greater genetic diversity, abundance, and hybrid fitness than controls that received immigrants from the source used to seed the mesocosms. In the second population, divergent immigrants had a slightly negative effect in one treatment, and the benefits of augmentation were less apparent overall, likely because this population started with higher genetic diversity and a lower reproductive rate that limited genetic admixture. Our results add to a growing consensus that gene flow can increase population fitness even when immigrants are more highly divergent and may help reduce uncertainty about the use of augmentation in conservation. © 2018 Society for Conservation Biology.

  18. Human population, grasshopper and plant species richness in European countries

    Science.gov (United States)

    Steck, Claude E.; Pautasso, Marco

    2008-11-01

    Surprisingly, several studies over large scales have reported a positive spatial correlation of people and biodiversity. This pattern has important implications for conservation and has been documented for well studied taxa such as plants, amphibians, reptiles, birds and mammals. However, it is unknown whether the pattern applies also to invertebrates other than butterflies and more work is needed to establish whether the species-people relationship is explained by both variables correlating with other environmental factors. We studied whether grasshopper species richness (Orthoptera, suborder Caelifera) is related to human population size in European countries. As expected, the number of Caelifera species increases significantly with increasing human population size. But this is not the case when controlling for country area, latitude and number of plant species. Variations in Caelifera species richness are primarily associated with variations in plant species richness. Caelifera species richness also increases with decreasing mean annual precipitation, Gross Domestic Product per capita (used as an indicator for economic development) and net fertility rate of the human population. Our analysis confirms the hypothesis that the broad-scale human population-biodiversity correlations can be explained by concurrent variations in factors other than human population size such as plant species richness, environmental productivity, or habitat heterogeneity. Nonetheless, more populated countries in Europe still have more Caelifera species than less populated countries and this poses a particular challenge for conservation.

  19. Adaptive synonymous mutations in an experimentally evolved Pseudomonas fluorescens population

    DEFF Research Database (Denmark)

    Bailey, Susan; Hinz, Aaron; Kassen, Rees

    2014-01-01

    Conventional wisdom holds that synonymous mutations, nucleotide changes that do not alter the encoded amino acid, have no detectable effect on phenotype or fitness. However, a growing body of evidence from both comparative and experimental studies suggests otherwise. Synonymous mutations have been...... shown to impact gene expression, protein folding and fitness, however, direct evidence that they can be positively selected, and so contribute to adaptation, is lacking. Here we report the recovery of two beneficial synonymous single base pair changes that arose spontaneously and independently...... in an experimentally evolved population of Pseudomonas fluorescens. We show experimentally that these mutations increase fitness by an amount comparable to non-synonymous mutations and that the fitness increases stem from increased gene expression. These results provide unequivocal evidence that synonymous mutations...

  20. Effects of an invasive plant on population dynamics in toads.

    Science.gov (United States)

    Greenberg, Daniel A; Green, David M

    2013-10-01

    When populations decline in response to unfavorable environmental change, the dynamics of their population growth shift. In populations that normally exhibit high levels of variation in recruitment and abundance, as do many amphibians, declines may be difficult to identify from natural fluctuations in abundance. However, the onset of declines may be evident from changes in population growth rate in sufficiently long time series of population data. With data from 23 years of study of a population of Fowler's toad (Anaxyrus [ = Bufo] fowleri) at Long Point, Ontario (1989-2011), we sought to identify such a shift in dynamics. We tested for trends in abundance to detect a change point in population dynamics and then tested among competing population models to identify associated intrinsic and extrinsic factors. The most informative models of population growth included terms for toad abundance and the extent of an invasive marsh plant, the common reed (Phragmites australis), throughout the toads' marshland breeding areas. Our results showed density-dependent growth in the toad population from 1989 through 2002. After 2002, however, we found progressive population decline in the toads associated with the spread of common reeds and consequent loss of toad breeding habitat. This resulted in reduced recruitment and population growth despite the lack of significant loss of adult habitat. Our results underscore the value of using long-term time series to identify shifts in population dynamics coincident with the advent of population decline. © 2013 Society for Conservation Biology.

  1. An advanced field experimental design to assess plant tolerance to heavy metal pollution

    Science.gov (United States)

    Łopata, Barbara; Szarek-Łukaszewska, Grażyna; Babst-Kostecka, Alicja

    2016-04-01

    Only a limited number of vascular plant species can survive and reproduce in toxic metalliferous environments. Among these species, pseudometallophytes are particularly interesting, as their metallicolous (M) populations on metalliferous soils and non-metallicolous (NM) populations on non-metalliferous soils show very pronounced ecological differences. Pseudometallophytes thus provide excellent opportunities for multidisciplinary research to improve phytoremediation and phytomining. Numerous methods have been developed to investigate plant adaptation to metal pollution, the majority of which has been conducted under controlled laboratory conditions. Although these efforts have significantly advanced our understanding of mechanisms underlying metal tolerance in plants, populations must be reciprocally transplanted to clearly identify natural selection. Only then is it possible to test, whether the fitness of native plants is higher than that of nonnative populations and thereby prove local adaptation. Here, we present an enhanced field experimental design aimed at verification of local adaptation to habitats with different levels of heavy metal soil contamination. At two M and two NM sites, we established a total of 12 plots (4 sites x 3 plots each), removed the existing local vegetation, and collected soil samples for chemical analyses (5 samples per plot). Plant collection (N= 480) from all four selected populations was established under laboratory conditions prior to the transplant experiment. Genotypes were randomly distributed within each plot (240 x 270 cm) and planted along a regulary spaced grid (30x30cm cell size) in spring 2015. Measurements will start in spring 2016, by which time plants are expected to have acclimatized to the local conditions. For the two subsiquent years, growth, survival, fitness, life cycle and herbivory consumption will be monitored for each transplant. On a weekly basis, we will record: 1) pictures of each transplant to determine

  2. Ambit determination method in estimating rice plant population density

    Directory of Open Access Journals (Sweden)

    Abu Bakar, B.,

    2017-11-01

    Full Text Available Rice plant population density is a key indicator in determining the crop setting and fertilizer application rate. It is therefore essential that the population density is monitored to ensure that a correct crop management decision is taken. The conventional method of determining plant population is by manually counting the total number of rice plant tillers in a 25 cm x 25 cm square frame. Sampling is done by randomly choosing several different locations within a plot to perform tiller counting. This sampling method is time consuming, labour intensive and costly. An alternative fast estimating method was developed to overcome this issue. The method relies on measuring the outer circumference or ambit of the contained rice plants in a 25 cm x 25 cm square frame to determine the number of tillers within that square frame. Data samples of rice variety MR219 were collected from rice plots in the Muda granary area, Sungai Limau Dalam, Kedah. The data were taken at 50 days and 70 days after seeding (DAS. A total of 100 data samples were collected for each sampling day. A good correlation was obtained for the variety of 50 DAS and 70 DAS. The model was then verified by taking 100 samples with the latching strap for 50 DAS and 70 DAS. As a result, this technique can be used as a fast, economical and practical alternative to manual tiller counting. The technique can potentially be used in the development of an electronic sensing system to estimate paddy plant population density.

  3. Rapid genetic erosion in pollutant-exposed experimental chironomid populations

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, Carsten [Abteilung Okologie und Evolution, Institut fuer Okologie, Evolution und Diversitaet, J. W. Goethe-Universitaet Frankfurt am Main, Siesmayerstrasse 70, 60054 Frankfurt am Main (Germany)], E-mail: cnowak@senckenberg.de; Vogt, Christian [Abteilung Aquatische Okotoxikologie, Institut fuer Okologie, Evolution und Diversitaet, J. W. Goethe-Universitaet Frankfurt am Main, Siesmayerstrasse 70, 60054 Frankfurt am Main (Germany)], E-mail: vogt@bio.uni-frankfurt.de; Pfenninger, Markus [Abteilung Okologie und Evolution, Institut fuer Okologie, Evolution und Diversitaet, J. W. Goethe-Universitaet Frankfurt am Main, Siesmayerstrasse 70, 60054 Frankfurt am Main (Germany)], E-mail: pfenninger@bio.uni-frankfurt.de; Schwenk, Klaus [Abteilung Okologie und Evolution, Institut fuer Okologie, Evolution und Diversitaet, J. W. Goethe-Universitaet Frankfurt am Main, Siesmayerstrasse 70, 60054 Frankfurt am Main (Germany)], E-mail: k.schwenk@bio.uni-frankfurt.de; Oehlmann, Joerg [Abteilung Aquatische Okotoxikologie, Institut fuer Okologie, Evolution und Diversitaet, J. W. Goethe-Universitaet Frankfurt am Main, Siesmayerstrasse 70, 60054 Frankfurt am Main (Germany)], E-mail: oehlmann@bio.uni-frankfurt.de; Streit, Bruno [Abteilung Okologie und Evolution, Institut fuer Okologie, Evolution und Diversitaet, J. W. Goethe-Universitaet Frankfurt am Main, Siesmayerstrasse 70, 60054 Frankfurt am Main (Germany)], E-mail: streit@bio.uni-frankfurt.de; Oetken, Matthias [Abteilung Aquatische Okotoxikologie, Institut fuer Okologie, Evolution und Diversitaet, J. W. Goethe-Universitaet Frankfurt am Main, Siesmayerstrasse 70, 60054 Frankfurt am Main (Germany)], E-mail: oetken@bio.uni-frankfurt.de

    2009-03-15

    Few studies have evaluated how effectively environmental contamination may reduce genetic diversity of a population. Here, we chose a laboratory approach in order to test if tributyltin (TBT) exposure at environmentally relevant concentrations leads to reduced genetic variation in the midge Chironomus riparius. Two TBT-exposed and two unexposed experimental populations were reared simultaneously in the laboratory for 12 generations. We recorded several life-history traits in each generation and monitored genetic variation over time using five variable microsatellite markers. TBT-exposed strains showed increased larval mortality (treatments: 43.8%; controls: 27.8%), slightly reduced reproductive output, and delayed larval development. Reduction of genetic variation was strongest and only significant in the TBT-exposed strains (treatments: -45.9%, controls: -24.4% of initial heterozygosity) after 12 generations. Our findings document that chemical pollution may lead to a rapid decrease in genetic diversity, which has important implications for conservation strategies and ecological management in polluted environments. - Chronic TBT exposure reduces allelic variation at five variable microsatellite loci in experimental populations of Chironomus riparius.

  4. Rapid genetic erosion in pollutant-exposed experimental chironomid populations

    International Nuclear Information System (INIS)

    Nowak, Carsten; Vogt, Christian; Pfenninger, Markus; Schwenk, Klaus; Oehlmann, Joerg; Streit, Bruno; Oetken, Matthias

    2009-01-01

    Few studies have evaluated how effectively environmental contamination may reduce genetic diversity of a population. Here, we chose a laboratory approach in order to test if tributyltin (TBT) exposure at environmentally relevant concentrations leads to reduced genetic variation in the midge Chironomus riparius. Two TBT-exposed and two unexposed experimental populations were reared simultaneously in the laboratory for 12 generations. We recorded several life-history traits in each generation and monitored genetic variation over time using five variable microsatellite markers. TBT-exposed strains showed increased larval mortality (treatments: 43.8%; controls: 27.8%), slightly reduced reproductive output, and delayed larval development. Reduction of genetic variation was strongest and only significant in the TBT-exposed strains (treatments: -45.9%, controls: -24.4% of initial heterozygosity) after 12 generations. Our findings document that chemical pollution may lead to a rapid decrease in genetic diversity, which has important implications for conservation strategies and ecological management in polluted environments. - Chronic TBT exposure reduces allelic variation at five variable microsatellite loci in experimental populations of Chironomus riparius

  5. Experimental Investigation and Modelling of a Wet Flue Gas Desulphurisation Pilot Plant

    DEFF Research Database (Denmark)

    Kiil, Søren; Michelsen, Michael Locht; Dam-Johansen, Kim

    1998-01-01

    A detailed model for a wet flue gas desulphurisation (FGD) pilot plant, based on the packed tower concept, has been developed. All important rate determining steps, absorption of SO2, oxidation of HSO3-, dissolution of limestone, and crystallisation of gypsum were included. Population balance...... equations, governing the description of particle size distributions of limestone in the plant, were derived. Model predictions were compared to experimental data such as gas phase concentration profiles of SO2, slurry pH-profiles, solids content of the slurry, liquid phase concentrations, and residual...

  6. Intervention analysis of power plant impact on fish populations

    International Nuclear Information System (INIS)

    Madenjian, C.P.

    1984-01-01

    Intervention analysis was applied to 10 yr (years 1973-1982) of field fish abundance data at the D. C. Cook Nuclear Power Plant, southeastern Lake Michigan. Three log-transformed catch series, comprising monthly observations, were examined for each combination of two species (alewife, Alosa pseudoharenga, or yellow perch, Perca flavescens) and gear (trawl or gill net): catch at the plant discharged transect, catch at the reference transect, and the ratio of plant catch to reference catch. Time series separated by age groups were examined. Based on intervention analysis, no change in the abundance of fish populations could be attributed to plant operation. Additionally, a modification of the intervention analysis technique was applied to investigate trends in abundance at both the plant discharge and reference transects. Significant declines were detected for abundance of alewife adults at both of the transects. Results of the trend analysis support the contention that the alewives have undergone a lakewide decrease in abundance during the 1970s

  7. Experimental study of population inversion in laser plasmas

    International Nuclear Information System (INIS)

    Bocher, J.L.; Busquet, M.; Combis, P.; Le Breton, J.P.; Louis-Jacquet, M.; Mexmain, J.M.; Naudy, M.

    1986-01-01

    Thin and thick composite targets of various materials (Al, CH, Au) have been irradiated on both circular and linear focal spots with the OCTAL laser facility at wavelengths 1.06 μm and 0.35 μm and laser irradiances 5 10 12 w/cm 2 to 5 10 14 w/cm 2 . X ray spectra in the range 5 - 8 A and 15 - 300 A recorded respectively by means of flat TlaP and grazing incidence spectrographs gave some experimental evidence of population inversion in aluminum plasma

  8. Experimental study of population inversion in laser plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Bocher, J.L.; Busquet, M.; Combis, P.; Le Breton, J.P.; Louis-Jacquet, M.; Mexmain, J.M.; Naudy, M.

    1986-10-01

    Thin and thick composite targets of various materials (Al, CH, Au) have been irradiated on both circular and linear focal spots with the OCTAL laser facility at wavelengths 1.06 ..mu..m and 0.35 ..mu..m and laser irradiances 5 10/sup 12/ w/cm/sup 2/ to 5 10/sup 14/ w/cm/sup 2/. X-ray spectra in the range 5 - 8 A and 15 - 300 A recorded respectively by means of flat TlaP and grazing incidence spectrographs gave some experimental evidence of population inversion in aluminum plasma.

  9. Experimental study of population inversion in laser plasmas

    International Nuclear Information System (INIS)

    Bocher, J.L.; Busquet, M.; Combis, M.; Le Breton, J.P.; Louis-Jacquet, M.; Mexmain, J.M.; Naudy, M.

    1986-06-01

    Thin and thick composite targets of various material (Al, CH, Au) have been irradiated on both circular and linear focal spot with the laser Octal facility at wavelength 1.06 μm and 0.35 μm and laser irradiances (5.10 12 .W/cm 2 to 5.10 14 .W/cm 2 ). X-ray spectra, in the ranges 5-8 A and 15 - 300 A, recorded respectively by means of flat TIAP and grazing incidence spectrographs show an experimental evidence of population inversion in aluminium plasmas

  10. Korean experimental studies on the radionuclide transfer in crop plants

    International Nuclear Information System (INIS)

    Choi, Y.H.; Lim, K.M.; Choi, G.S.; Choi, H.J.; Lee, H.S.; Lee, C.W.

    2003-01-01

    In Korea, data on the radionuclide transfer in crop plants have been produced almost exclusively at the Korea Atomic Energy Research Institute (KAERI), where experimental studies have been carried out for last about 20 years. These works are briefly outlined in this paper which shows results with emphasis on rice data. Soil-to-plant transfer factors of radionuclides including radiocesium and radiostrontium were measured through greenhouse experiments for various crop species. Not only conventional transfer factors but also those based on the activity applied to unit area of the soil surface were investigated. Field studies on the transfer of fallout 137 Cs were carried out for rice and Chinese cabbage. As for parameters in relation to direct plant contamination, interception factors and translocation factors were obtained through greenhouse experiments. Plants were sprayed with radioactive solutions containing 54 Mn, 57 Co, 85 Sr, 103 Ru and 134 Cs at different growth stages. Experiments on the plant exposure to airborne HTO and I 2 vapor were also carried out. The transfer parameters generally showed great variations with soils, crops, radionuclides and isotope application times. Most experiments were designed for acute releases of radioactivity but some results are applicable to steady-state conditions, too. Many of the produced data would be of use also in other countries including Japan. (author)

  11. Plant Mating Systems Often Vary Widely Among Populations

    Directory of Open Access Journals (Sweden)

    Michael R. Whitehead

    2018-04-01

    Full Text Available Most flowering plants are hermaphroditic, yet the proportion of seeds fertilized by self and outcross pollen varies widely among species, ranging from predominant self-fertilization to exclusive outcrossing. A population's rate of outcrossing has important evolutionary outcomes as it influences genetic structure, effective population size, and offspring fitness. Because most mating system studies have quantified outcrossing rates for just one or two populations, past reviews of mating system diversity have not been able to characterize the extent of variation among populations. Here we present a new database of more than 30 years of mating system studies that report outcrossing rates for three or more populations per species. This survey, which includes 741 populations from 105 species, illustrates substantial and prevalent among-population variation in the mating system. Intermediate outcrossing rates (mixed mating are common; 63% of species had at least one mixed mating population. The variance among populations and within species was not significantly correlated with pollination mode or phylogeny. Our review underscores the need for studies exploring variation in the relative influence of ecological and genetic factors on the mating system, and how this varies among populations. We conclude that estimates of outcrossing rates from single populations are often highly unreliable indicators of the mating system of an entire species.

  12. Causes and consequences of complex population dynamics in an annual plant, Cardamine pensylvanica

    Energy Technology Data Exchange (ETDEWEB)

    Crone, E.E.

    1995-11-08

    The relative importance of density-dependent and density-independent factors in determining the population dynamics of plants has been widely debated with little resolution. In this thesis, the author explores the effects of density-dependent population regulation on population dynamics in Cardamine pensylvanica, an annual plant. In the first chapter, she shows that experimental populations of C. pensylvanica cycled from high to low density in controlled constant-environment conditions. These cycles could not be explained by external environmental changes or simple models of direct density dependence (N{sub t+1} = f[N{sub t}]), but they could be explained by delayed density dependence (N{sub t+1} = f[N{sub t}, N{sub t+1}]). In the second chapter, she shows that the difference in the stability properties of population growth models with and without delayed density dependence is due to the presence of Hopf as well as slip bifurcations from stable to chaotic population dynamics. She also measures delayed density dependence due to effects of parental density on offspring quality in C. pensylvanica and shows that this is large enough to be the cause of the population dynamics observed in C. pensylvanica. In the third chapter, the author extends her analyses of density-dependent population growth models to include interactions between competing species. In the final chapter, she compares the effects of fixed spatial environmental variation and variation in population size on the evolutionary response of C. pensylvanica populations.

  13. Radiation burden of population in nuclear power plant siting

    International Nuclear Information System (INIS)

    Navratil, J.

    The significance is discussed of the determination of the radiobiological consequences of normal operation and design basis accidents in nuclear power plant siting. The basic diagram and brief description is given of the programme for calculating the radiation load of the population in the surroundings of the nuclear power plant. The programme consists of two subprogrammes, i.e., the dispersion of radioactive gases (for normal operation and for accidents), the main programme for the determination of biological consequences and one auxiliary programme (the distribution of the population in the surroundings of the power plant). The four most important types of exposure to ionizing radiation are considered, namely inhalation, external irradiation from a cloud, ingestion (water, milk, vegetables), external irradiation from the deposit. (B.S.)

  14. Effects of host-plant population size and plant sex on a specialist leaf-miner

    DEFF Research Database (Denmark)

    Bañuelos, María-José; Kollmann, Johannes Christian

    2011-01-01

    of the host-plant, and density-dependent relationships. Leaf-miners are specialised herbivores that leave distinct traces on infested leaves in the form of egg scars, mines, signs of predation and emergence holes. This allows the life cycle of the insect to be reconstructed and the success at the different...... punctures left by adults were marginally more frequent on male plants, whereas egg scars and mines were more common on females. Overall survival rate from egg stage to adult emergence was higher on female plants. Egg density was negatively correlated with hatching, while mine density was positively...... stages to be estimated. The main stages of the leaf-miner Phytomyza ilicis were recorded in eleven populations of the evergreen host Ilex aquifolium in Denmark. Survival rates were calculated and related to population size, sex of the host plant, and egg and mine densities. Host population size...

  15. Development of an experimental approach to study coupled soil-plant-atmosphere processes using plant analogs

    Science.gov (United States)

    Trautz, Andrew C.; Illangasekare, Tissa H.; Rodriguez-Iturbe, Ignacio; Heck, Katharina; Helmig, Rainer

    2017-04-01

    The atmosphere, soils, and vegetation near the land-atmosphere interface are in a state of continuous dynamic interaction via a myriad of complex interrelated feedback processes which collectively, remain poorly understood. Studying the fundamental nature and dynamics of such processes in atmospheric, ecological, and/or hydrological contexts in the field setting presents many challenges; current experimental approaches are an important factor given a general lack of control and high measurement uncertainty. In an effort to address these issues and reduce overall complexity, new experimental design considerations (two-dimensional intermediate-scale coupled wind tunnel-synthetic aquifer testing using synthetic plants) for studying soil-plant-atmosphere continuum soil moisture dynamics are introduced and tested in this study. Validation of these experimental considerations, particularly the adoption of synthetic plants, is required prior to their application in future research. A comparison of three experiments with bare soil surfaces or transplanted with a Stargazer lily/limestone block was used to evaluate the feasibility of the proposed approaches. Results demonstrate that coupled wind tunnel-porous media experimentation, used to simulate field conditions, reduces complexity, and enhances control while allowing fine spatial-temporal resolution measurements to be made using state-of-the-art technologies. Synthetic plants further help reduce system complexity (e.g., airflow) while preserving the basic hydrodynamic functions of plants (e.g., water uptake and transpiration). The trends and distributions of key measured atmospheric and subsurface spatial and temporal variables (e.g., soil moisture, relative humidity, temperature, air velocity) were comparable, showing that synthetic plants can be used as simple, idealized, nonbiological analogs for living vegetation in fundamental hydrodynamic studies.

  16. Experimental investigation of buried tritium in plant and animal tissues

    International Nuclear Information System (INIS)

    Kim, S. B.; Workman, W. J. G.; Davis, P. A.

    2008-01-01

    Buried exchangeable tritium appears as part of organically bound tritium (OBT) in the traditional experimental determination of OBT. Since buried tritium quickly exchanges with hydrogen atoms in the body following ingestion, assuming that it is part of OBT rather than part of tritiated water (HTO) could result in a significant overestimate of the ingestion dose. This paper documents an experimental investigation into the existence, amount and significance of buried tritium in plant and fish samples. OBT concentrations in the samples were determined in the traditional way and also following denaturing with five chemical solutions that break down large molecules and expose buried tritium to exchange with free hydrogen atoms. A comparison of the OBT concentrations before and after denaturing, together with the concentration of HTO in the supernatant obtained after denaturing, suggests that buried OBT may exist but makes up less than 5% of the OBT concentration in plants and at most 20% of the OBT concentration in fish. The effects of rinse time and rinse water volumes were investigated to optimize the removal of exchangeable OBT from the samples. (authors)

  17. Effects of host-plant population size and plant sex on a specialist leaf-miner

    Science.gov (United States)

    Bañuelos, María-José; Kollmann, Johannes

    2011-03-01

    Animal population density has been related to resource patch size through various hypotheses such as those derived from island biogeography and resource concentration theory. This theoretical framework can be also applied to plant-herbivore interactions, and it can be modified by the sex of the host-plant, and density-dependent relationships. Leaf-miners are specialised herbivores that leave distinct traces on infested leaves in the form of egg scars, mines, signs of predation and emergence holes. This allows the life cycle of the insect to be reconstructed and the success at the different stages to be estimated. The main stages of the leaf-miner Phytomyza ilicis were recorded in eleven populations of the evergreen host Ilex aquifolium in Denmark. Survival rates were calculated and related to population size, sex of the host plant, and egg and mine densities. Host population size was negatively related to leaf-miner prevalence, with larger egg and mine densities in small populations. Percentage of eggs hatching and developing into mines, and percentage of adult flies emerging from mines also differed among host populations, but were not related to population size or host cover. Feeding punctures left by adults were marginally more frequent on male plants, whereas egg scars and mines were more common on females. Overall survival rate from egg stage to adult emergence was higher on female plants. Egg density was negatively correlated with hatching, while mine density was positively correlated with emergence of the larvae. The inverse effects of host population size were not in line with predictions based on island biogeography and resource concentration theory. We discuss how a thorough knowledge of the immigration behaviour of this fly might help to understand the patterns found.

  18. Experimental depletion of different renal interstitial cell populations

    International Nuclear Information System (INIS)

    Bohman, S.O.; Sundelin, B.; Forsum, U.; Tribukait, B.

    1988-01-01

    To define different populations of renal interstitial cells and investigate some aspects of their function, we studied the kidneys of normal rats and rats with hereditary diabetes insipidus (DI, Brattleboro) after experimental manipulations expected to alter the number of interstitial cells. DI rats showed an almost complete loss of interstitial cells in their renal papillae after treatment with a high dose of vasopressin. In spite of the lack of interstitial cells, the animals concentrated their urine to the same extent as vasopressin-treated normal rats, indicating that the renomedullary interstitial cells do not have an important function in concentrating the urine. The interstitial cells returned nearly to normal within 1 week off vasopressin treatment, suggesting a rapid turnover rate of these cells. To further distinguish different populations of interstitial cells, we studied the distribution of class II MHC antigen expression in the kidneys of normal and bone-marrow depleted Wistar rats. Normal rats had abundant class II antigen-positive interstitial cells in the renal cortex and outer medulla, but not in the inner medulla (papilla). Six days after 1000 rad whole body irradiation, the stainable cells were almost completely lost, but electron microscopic morphometry showed a virtually unchanged volume density of interstitial cells in the cortex and outer medulla, as well as the inner medulla. Thus, irradiation abolished the expression of the class II antigen but caused no significant depletion of interstitial cells

  19. Population, 54 Activities: An Experimental Unit, First Draft.

    Science.gov (United States)

    Denver Univ., CO. Center for Teaching International Relations.

    Supplementary teaching activities at the junior- and senior-high school level on issues and topics involving population factors are provided. Topics include population growth, demography, graphing, population distribution, and population control. Community and national census factors as well as world population are studied. Students are helped to…

  20. Waste Isolation Pilot Plant in situ experimental program for HLW

    International Nuclear Information System (INIS)

    Molecke, M.A.

    1977-01-01

    The Waste Isolation Pilot Plant (WIPP) will be a facility to demonstrate the environmental and operational safety of storing radioactive wastes in a deep geologic bedded salt facility. The WIPP will be located in southeastern New Mexico, approximately 30 miles east of the city of Carlsbad. The major focus of the pilot plant operation involves ERDA defense related low and intermediate-level transuranic wastes. The scope of the project also specifically includes experimentation utilizing commercially generated high-level wastes, or alternatively, spent unreprocessed fuel elements. WIPP HLW experiments are being conducted in an inter-related laboratory, bench-scale, and in situ mode. This presentation focuses on the planned in situ experiments which, depending on the availability of commercially reprocessed waste plus delays in the construction schedule of the WIPP, will begin in approximately 1985. Such experiments are necessary to validate preceding laboratory results and to provide actual, total conditions of geologic storage which cannot be adequately simulated. One set of planned experiments involves emplacing bare HLW fragments into direct contact with the bedded salt environment. A second set utilizes full-size canisters of waste emplaced in the salt in the same manner as planned for a future HLW repository. The bare waste experiments will study in an accelerated manner waste-salt bed-brine interactions including matrix integrity/degradation, brine leaching, system chemistry, and potential radionuclide migration through the salt bed. Utilization of full-size canisters of HLW in situ permits us to demonstrate operational effectiveness and safety. Experiments will evaluate corrosion and compatibility interactions between the waste matrix, canister and overpack materials, getter materials, stored energy, waste buoyancy, etc. Using full size canisters also allows us to demonstrate engineered retrievability of wastes, if necessary, at the end of experimentation

  1. Effects in Plant Populations Resulting from Chronic Radiation Exposure

    Energy Technology Data Exchange (ETDEWEB)

    Geras' kin, Stanislav A.; Volkova, Polina Yu.; Vasiliyev, Denis V.; Dikareva, Nina S.; Oudalova, Alla A. [Russian Institute of Agricultural Radiology and Agroecology, 249032, Obninsk (Russian Federation)

    2014-07-01

    Human industrial activities have left behind a legacy of ecosystems strongly impacted by a wide range of contaminants, including radionuclides. Phyto-toxic effects of acute impact are well known, but the consequences of long-term chronic exposure to low pollutant concentrations is neither well understood nor adequately included in risk assessments. To understand effects of real-world contaminant exposure properly we must pay attention to what is actually going on in the field. However, for many wildlife groups and endpoints, there are no, or very few, studies that link accumulation, chronic exposure and biological effects in natural settings. To fill the gaps, results of field studies carried out on different plant species (winter rye and wheat, spring barley, oats, Scots pine, wild vetch, crested hair-grass) in various radioecological situations (nuclear weapon testing, the Chernobyl accident, uranium and radium processing) to investigate effects of long-term chronic exposure to radionuclides are discussed. Because each impacted site developed in its own way due to a unique history of events, the experience from one case study is rarely directly applicable to another situation. In spite of high heterogeneity in response, we have detected several general patterns. Plant populations growing in areas with relatively low levels of pollution are characterized by the increased level of both cytogenetic alterations and genetic diversity. Accumulation of cellular alterations may afterward influence biological parameters important for populations such as health and reproduction. Presented data provide evidence that in plant populations inhabiting heavily contaminated territories cytogenetic damage were accompanied by decrease in reproductive ability. In less contaminated sites, because of the scarcity of data available, it is impossible to establish exactly the relationship between cytogenetic effects and reproductive ability. Radioactive contamination of the plants

  2. Do we need demographic data to forecast plant population dynamics?

    Science.gov (United States)

    Tredennick, Andrew T.; Hooten, Mevin B.; Adler, Peter B.

    2017-01-01

    Rapid environmental change has generated growing interest in forecasts of future population trajectories. Traditional population models built with detailed demographic observations from one study site can address the impacts of environmental change at particular locations, but are difficult to scale up to the landscape and regional scales relevant to management decisions. An alternative is to build models using population-level data that are much easier to collect over broad spatial scales than individual-level data. However, it is unknown whether models built using population-level data adequately capture the effects of density-dependence and environmental forcing that are necessary to generate skillful forecasts.Here, we test the consequences of aggregating individual responses when forecasting the population states (percent cover) and trajectories of four perennial grass species in a semi-arid grassland in Montana, USA. We parameterized two population models for each species, one based on individual-level data (survival, growth and recruitment) and one on population-level data (percent cover), and compared their forecasting accuracy and forecast horizons with and without the inclusion of climate covariates. For both models, we used Bayesian ridge regression to weight the influence of climate covariates for optimal prediction.In the absence of climate effects, we found no significant difference between the forecast accuracy of models based on individual-level data and models based on population-level data. Climate effects were weak, but increased forecast accuracy for two species. Increases in accuracy with climate covariates were similar between model types.In our case study, percent cover models generated forecasts as accurate as those from a demographic model. For the goal of forecasting, models based on aggregated individual-level data may offer a practical alternative to data-intensive demographic models. Long time series of percent cover data already exist

  3. Experimental program plan for the Waste Isolation Pilot Plant

    Energy Technology Data Exchange (ETDEWEB)

    1994-01-01

    The US Department of Energy has prepared this Experimental Program Plan for the Waste Isolation Pilot Plant (EPP) to provide a summary of the DOE experimental efforts needed for the performance assessment process for the WIPP, and of the linkages of this process to the appropriate regulations. The Plan encompasses a program of analyses of the performance of the planned repository based on scientific studies, including tests with transuranic waste at laboratory sites, directed at evaluating compliance with the principal regulations governing the WIPP. The Plan begins with background information on the WIPP project, the requirements of the LWA (Land Withdrawal Act), and its objective and scope. It then presents an overview of the regulatory requirements and the compliance approach. Next are comprehensive discussions of plans for compliance with disposal regulations, followed by the SWDA (Solid Waste Disposal Act) and descriptions of activity programs designed to provide information needed for determining compliance. Descriptions and justifications of all currently planned studies designed to support regulatory compliance activities are also included.

  4. Experimental program plan for the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    1994-01-01

    The US Department of Energy has prepared this Experimental Program Plan for the Waste Isolation Pilot Plant (EPP) to provide a summary of the DOE experimental efforts needed for the performance assessment process for the WIPP, and of the linkages of this process to the appropriate regulations. The Plan encompasses a program of analyses of the performance of the planned repository based on scientific studies, including tests with transuranic waste at laboratory sites, directed at evaluating compliance with the principal regulations governing the WIPP. The Plan begins with background information on the WIPP project, the requirements of the LWA (Land Withdrawal Act), and its objective and scope. It then presents an overview of the regulatory requirements and the compliance approach. Next are comprehensive discussions of plans for compliance with disposal regulations, followed by the SWDA (Solid Waste Disposal Act) and descriptions of activity programs designed to provide information needed for determining compliance. Descriptions and justifications of all currently planned studies designed to support regulatory compliance activities are also included

  5. Plant-associated bacterial populations on native and invasive plant species: comparisons between 2 freshwater environments.

    Science.gov (United States)

    Olapade, Ola A; Pung, Kayleigh

    2012-06-01

    Plant-microbial interactions have been well studied because of the ecological importance of such relationships in aquatic systems. However, general knowledge regarding the composition of these biofilm communities is still evolving, partly as a result of several confounding factors that are attributable to plant host properties and to hydrodynamic conditions in aquatic environments. In this study, the occurrences of various bacterial phylogenetic taxa on 2 native plants, i.e., mayapple (Podophyllum peltatum L.) and cow parsnip (Heracleum maximum Bartram), and on an invasive species, i.e., garlic mustard (Alliaria petiolata (M. Bieb.) Cavara & Grande), were quantitatively examined using nucleic acid staining and fluorescence in situ hybridization. The plants were incubated in triplicates for about a week within the Kalamazoo River and Pierce Cedar Creek as well as in microcosms. The bacterial groups targeted for enumeration are known to globally occur in relatively high abundance and are also ubiquitously distributed in freshwater environments. Fluorescence in situ hybridization analyses of the bacterioplankton assemblages revealed that the majority of bacterial cells that hybridized with the different probes were similar between the 2 sites. In contrast, the plant-associated populations while similar on the 3 plants incubated in Kalamazoo River, their representations were highest on the 2 native plants relative to the invasive species in Pierce Cedar Creek. Overall, our results further suggested that epiphytic bacterial assemblages are probably under the influences of and probably subsequently respond to multiple variables and conditions in aquatic milieus.

  6. Population and community ecology of the rare plant amsinckia grandiflora

    Energy Technology Data Exchange (ETDEWEB)

    Carlsen, T.M.

    1996-11-01

    Research was conducted between the fall of 1992 and the spring on the population and community ecology of the rare annual plant, Amsinckia glandiflora (Gray) Kleeb. ex Greene (Boraginaceae). The research goal was to investigate the causes of the species rarity, data useful to restorative efforts. The work focused on the examination of competitive suppression by exotic annual grasses; comparisons with common, weedy congener; and the role of litter cover and seed germination and seedling establishment. Annual exotic grasses reduced A. grandiflora reproductive output to a greater extent than did the native perennial bunch grass.

  7. 78 FR 35719 - Endangered and Threatened Wildlife and Plants; Proposed Revision To the Nonessential Experimental...

    Science.gov (United States)

    2013-06-13

    ... governing the Mexican wolf nonessential experimental population designation. Background Our approach in this... private activities within or adjacent to the experimental population area. Furthermore, as set forth in 50...; Proposed Revision To the Nonessential Experimental Population of the Mexican Wolf AGENCY: Fish and Wildlife...

  8. Experimental evidence that density dependence strongly influences plant invasions through fragmented landscapes.

    Science.gov (United States)

    Williams, Jennifer L; Levine, Jonathan M

    2018-04-01

    Populations of range expanding species encounter patches of both favorable and unfavorable habitat as they spread across landscapes. Theory shows that increasing patchiness slows the spread of populations modeled with continuously varying population density when dispersal is not influence by the environment or individual behavior. However, as is found in uniformly favorable landscapes, spread remains driven by fecundity and dispersal from low density individuals at the invasion front. In contrast, when modeled populations are composed of discrete individuals, patchiness causes populations to build up to high density before dispersing past unsuitable habitat, introducing an important influence of density dependence on spread velocity. To test the hypothesized interaction between habitat patchiness and density dependence, we simultaneously manipulated these factors in a greenhouse system of annual plants spreading through replicated experimental landscapes. We found that increasing the size of gaps and amplifying the strength of density dependence both slowed spread velocity, but contrary to predictions, the effect of amplified density dependence was similar across all landscape types. Our results demonstrate that the discrete nature of individuals in spreading populations has a strong influence on how both landscape patchiness and density dependence influence spread through demographic and dispersal stochasticity. Both finiteness and landscape structure should be critical components to theoretical predictions of future spread for range expanding native species or invasive species colonizing new habitat. © 2018 by the Ecological Society of America.

  9. Genetic variability in chronic irradiated plant populations - Polymorphism and activity of antioxidant enzymes in chronic irradiated plant populations

    Energy Technology Data Exchange (ETDEWEB)

    Volkova, Polina Y.; Geras' kin, Stanislav A. [Russian Institute of Agricultural Radiology and Agroecology, 249030, Obninsk, Kievskoe shosse 109 km (Russian Federation)

    2014-07-01

    Introduction: The gene pool of natural population is constantly changing in order to provide the greatest fitness at this time. Ability of population to adapt to changing environmental conditions depends on genetic polymorphism of traits which are operates by selection. Chronic stress exposure can change amount or structure intra-population variability. Therefore, it is necessary to analyze the relationships between genetic polymorphism and stress factors, such as radiation exposure. This studies my assist in the development of new bio-indication methods. Materials and methods: Studying sites: Bryansk region is the most contaminated region of Russia as a result of Chernobyl accident. The initial activity by {sup 137}Cs on this territory reached 1 MBq/m{sup 2} above surface. Our study conducted in several districts of Bryansk region, which are characterized the most dose rate. Experimental sites similar to climate characteristics, stand of trees is homogeneous, pine trees take up a significant part of phytocenosis. Heavy metals content in soils and cones be within background. Dose rates vary from 0.14 to 130 mGy/year. Object: Pinus sylvestris L.,the dominant tree species in North European and Asian boreal forests. Scots pine has a long maturation period (18-20 month), which means that significant DNA damage may accumulate in the undifferentiated stem cells, even at low doses (or dose rates) during exposure to low concentrations of contaminants Isozyme analysis: We evaluated isozyme polymorphism of three antioxidant enzymes: superoxide dismutase, glutatione reductase and glutatione peroxidase. Analysis of enzymes activities: We chose key enzymes of antioxidant system for this experiment: superoxide dismutase, catalase and peroxidase. Results and conclusions: We estimated frequency of each allele in reference and experimental populations. based It was showed that frequency of rare alleles increase in chronic irradiated populations, i.e. increase the sampling variance

  10. Experimental evidence for a demographic cline in Panstrongylus megistus populations

    Directory of Open Access Journals (Sweden)

    Barbosa Silvia E

    2001-01-01

    Full Text Available The population biology of three populations of Panstrongylus megistus was compared to determine possible influence on the behaviour and epidemiological importance of this species. The results demonstrated differences in terms of egg eclosion time, nymphal mortality and development rates, and feeding and defaecation rates. These differences appeared to follow a geographical cline, primarily reflecting different degrees of adaptation to domestic habitats.

  11. Evolution in plant populations as a driver of ecological changes in arthropod communities.

    Science.gov (United States)

    Johnson, Marc T J; Vellend, Mark; Stinchcombe, John R

    2009-06-12

    Heritable variation in traits can have wide-ranging impacts on species interactions, but the effects that ongoing evolution has on the temporal ecological dynamics of communities are not well understood. Here, we identify three conditions that, if experimentally satisfied, support the hypothesis that evolution by natural selection can drive ecological changes in communities. These conditions are: (i) a focal population exhibits genetic variation in a trait(s), (ii) there is measurable directional selection on the trait(s), and (iii) the trait(s) under selection affects variation in a community variable(s). When these conditions are met, we expect evolution by natural selection to cause ecological changes in the community. We tested these conditions in a field experiment examining the interactions between a native plant (Oenothera biennis) and its associated arthropod community (more than 90 spp.). Oenothera biennis exhibited genetic variation in several plant traits and there was directional selection on plant biomass, life-history strategy (annual versus biennial reproduction) and herbivore resistance. Genetically based variation in biomass and life-history strategy consistently affected the abundance of common arthropod species, total arthropod abundance and arthropod species richness. Using two modelling approaches, we show that evolution by natural selection in large O. biennis populations is predicted to cause changes in the abundance of individual arthropod species, increases in the total abundance of arthropods and a decline in the number of arthropod species. In small O. biennis populations, genetic drift is predicted to swamp out the effects of selection, making the evolution of plant populations unpredictable. In short, evolution by natural selection can play an important role in affecting the dynamics of communities, but these effects depend on several ecological factors. The framework presented here is general and can be applied to other systems to

  12. Evolution in plant populations as a driver of ecological changes in arthropod communities

    Science.gov (United States)

    Johnson, Marc T.J.; Vellend, Mark; Stinchcombe, John R.

    2009-01-01

    Heritable variation in traits can have wide-ranging impacts on species interactions, but the effects that ongoing evolution has on the temporal ecological dynamics of communities are not well understood. Here, we identify three conditions that, if experimentally satisfied, support the hypothesis that evolution by natural selection can drive ecological changes in communities. These conditions are: (i) a focal population exhibits genetic variation in a trait(s), (ii) there is measurable directional selection on the trait(s), and (iii) the trait(s) under selection affects variation in a community variable(s). When these conditions are met, we expect evolution by natural selection to cause ecological changes in the community. We tested these conditions in a field experiment examining the interactions between a native plant (Oenothera biennis) and its associated arthropod community (more than 90 spp.). Oenothera biennis exhibited genetic variation in several plant traits and there was directional selection on plant biomass, life-history strategy (annual versus biennial reproduction) and herbivore resistance. Genetically based variation in biomass and life-history strategy consistently affected the abundance of common arthropod species, total arthropod abundance and arthropod species richness. Using two modelling approaches, we show that evolution by natural selection in large O. biennis populations is predicted to cause changes in the abundance of individual arthropod species, increases in the total abundance of arthropods and a decline in the number of arthropod species. In small O. biennis populations, genetic drift is predicted to swamp out the effects of selection, making the evolution of plant populations unpredictable. In short, evolution by natural selection can play an important role in affecting the dynamics of communities, but these effects depend on several ecological factors. The framework presented here is general and can be applied to other systems to

  13. Morpho-physiological and productive biometry in semi-erect cultivars of the cowpea under different plant populations

    Directory of Open Access Journals (Sweden)

    Antônio Aécio de Carvalho Bezerra

    Full Text Available ABSTRACT The aim of this study was to evaluate morpho-physiological and productive characteristics in four semi-erect cultivars of the cowpea under five plant populations. The experiment was conducted in the experimental area of Embrapa Meio-Norte in Teresina in the State of Piauí, Brazil (PI. The experimental design was of randomised complete blocks with four replications, in a 4 x 5 factorial scheme, for evaluating four cultivars (BRS Guariba, BRS Novaera, BRS Potengi and BRS Tumucumaque and five plant populations (105, 2x105, 3x105, 4x105 and 5x105 plants ha-1. There were significant differences between cultivars for primary branch length (PBL, number of lateral branches (NLB, 100-grain weight (HGW, and dry-grain yield (GY. The maximum PBL of 58.5 cm was obtained with 300 thousand plants ha-1, corresponding to an increase of 11.5% when compared to 100 thousand plants ha-1. However, there was a reduction of 91.2% in NLB when compared to the populations of 100 and 500 thousand plants ha-1. The increases of 188% obtained in the leaf area index (LAI in the range of 100 to 500 thousand plants ha-1 explain the linear increase in the crop growth rate (CGR as being due to the greater production of leaf area; also, the decreases seen in the net assimilation rate (NAR, especially in the range of 100 to 300 thousand plants ha-1, are explained as due to the consequent self-shading, which was intensified in the larger populations. LAI, light interception, and CGR in the cultivars increase in response to higher densities. HGW and GY are not significantly affected by the different populations.

  14. Culture Methodology for Experimental Investigations Involving Rooted Submersed Aquatic Plants.

    Science.gov (United States)

    1984-11-01

    stolons or runners are best planted as intact plants (Sculthorpe 1967). Many species can be propagated from seed in addition to the above methods...J. 1984. Growth response of Myriophyllwm spicatu and Hydrilla verticillata when exposed to continuous, low concentrations of fluridone . Tech. Rept. A...aquatic plants, water, and bottom sediments. Weed Sci. 20:482-486. Sastroutomo, S. S. 1980. Dormancy and germination in axillary turions of iijiilZla

  15. 76 FR 17439 - Nonessential Experimental Populations of Gray Wolves in the Northern Rocky Mountains; Lethal Take...

    Science.gov (United States)

    2011-03-29

    ... nonessential experimental population areas for the gray wolf under section 10(j) of the ESA: the Yellowstone...-0000-C3] Nonessential Experimental Populations of Gray Wolves in the Northern Rocky Mountains; Lethal Take of Wolves in the West Fork Elk Management Unit of Montana; Draft Environmental Assessment AGENCY...

  16. 76 FR 7875 - Nonessential Experimental Populations of Gray Wolves in the Northern Rocky Mountains; Lethal Take...

    Science.gov (United States)

    2011-02-11

    ... the central Idaho and Yellowstone area nonessential experimental populations of gray wolves in the...-0000-C3] Nonessential Experimental Populations of Gray Wolves in the Northern Rocky Mountains; Lethal Take of Wolves in the Lolo Elk Management Zone of Idaho; Draft Environmental Assessment AGENCY: Fish...

  17. Effect of crop development on biogenic emissions from plant populations grown in closed plant growth chambers

    Science.gov (United States)

    Batten, J. H.; Stutte, G. W.; Wheeler, R. M.

    1995-01-01

    The Biomass Production Chamber at John F. Kennedy Space Center is a closed plant growth chamber facility that can be used to monitor the level of biogenic emissions from large populations of plants throughout their entire growth cycle. The head space atmosphere of a 26-day-old lettuce (Lactuca sativa cv. Waldmann's Green) stand was repeatedly sampled and emissions identified and quantified using GC-mass spectrometry. Concentrations of dimethyl sulphide, carbon disulphide, alpha-pinene, furan and 2-methylfuran were not significantly different throughout the day; whereas, isoprene showed significant differences in concentration between samples collected in light and dark periods. Volatile organic compounds from the atmosphere of wheat (Triticum aestivum cv. Yecora Rojo) were analysed and quantified from planting to maturity. Volatile plant-derived compounds included 1-butanol, 2-ethyl-1-hexanol, nonanal, benzaldehyde, tetramethylurea, tetramethylthiourea, 2-methylfuran and 3-methylfuran. Concentrations of volatiles were determined during seedling establishment, vegetative growth, anthesis, grain fill and senescence and found to vary depending on the developmental stage. Atmospheric concentrations of benzaldehyde and nonanal were highest during anthesis, 2-methylfuran and 3-methylfuran concentrations were greatest during grain fill, and the concentration of the tetramethylurea peaked during senescence.

  18. Physiology of Plants, Science (Experimental): 5315.41.

    Science.gov (United States)

    Gunn, William C.

    This unit of instruction deals with the physiological activities of plants. Attention is focused on the principles which underlie the activities of the typical green land plant. Emphasis is placed on biological processes such as photosynthesis, water transport, light responses, mineral nutrition, reproduction, and growth. The prerequisite for…

  19. Introduction to the Plant World, Science (Experimental): 5311.11.

    Science.gov (United States)

    Payne, Leonard O.

    This unit of instruction was designed as a laboratory-oriented course for very low achievers to show how plants are involved in every aspect of their lives. Detailed practical experience in handling and investigating plants, and the use of films, models, and field trips are combined with basic minimal research to guide the student to a better…

  20. Experimental evidence of 'floaters' in two isolated populations of an ...

    African Journals Online (AJOL)

    Using a combination of radio telemetry, dawn calls, visual observations and targetted playbacks in one 16ha plot per fragment, 52 individuals of different territorial status were identified. Ngangao hosted 14 resident and 13 floating males, while Chawia hosted eight residents and two floaters. Population Chawia (but not ...

  1. Experimental effects of herbivore density on above-ground plant biomass in an alpine grassland ecosystem

    OpenAIRE

    Austrheim, Gunnar; Speed, James David Mervyn; Martinsen, Vegard; Mulder, Jan; Mysterud, Atle

    2014-01-01

    Herbivores may increase or decrease aboveground plant productivity depending on factors such as herbivore density and habitat productivity. The grazing optimization hypothesis predicts a peak in plant production at intermediate herbivore densities, but has rarely been tested experimentally in an alpine field setting. In an experimental design with three densities of sheep (high, low, and no sheep), we harvested aboveground plant biomass in alpine grasslands prior to treatment and after five y...

  2. Air and the origin of the experimental plant physiology.

    Science.gov (United States)

    Pennazio, Sergio

    2005-01-01

    It is well known that oxygen and carbon dioxide are two chemicals which enter the plant metabolism as nutrients. The bases of this nowadays obvious statement were placed in the 18th century by means of the works of ingenious naturalists such as Robert Boyle, Stephen Hales, Joseph Priestley, Jam Ingenhousz, Lazzaro Spallanzani and Theodore De Saussure. Till the end of the 17th century, the atmospheric air was considered as an ineffable spirit, the function of which was of physical nature. Boyle was the first naturalist to admit the possibility that respiration were an exchange of vapours occurring in the blood. Stephen Hales realised that air could be fixed by plants under the influence of solar light. Priestley showed that plants could regenerate the bad air making it breathable. Ingenhousz demonstrated that the green parts of plants performed the complete purification of air only under the influence of the light. Spallanzani discovered that plants respire and guessed that the good air (oxygen) originated from the fixed air (carbon dioxide). Finally, Theodore De Saussure showed that plants were able to adsorb carbon dioxide and to release oxygen in a proportional air. All these discoveries benefited of the results coming from investigations of scholars of the so-called "pneumatic chemistry" (Boyle himself, George Ernst Stahl, Joseph Black, Priestley himself, and many more others. But among all the eminent scientists above mentioned stands out the genius of Antoine Laurent Lavoisier, who revolutionised the chemistry of the 18th century ferrying it towards the modern chemistry.

  3. Experimental restoration of a fen plant community after peat mining

    Energy Technology Data Exchange (ETDEWEB)

    Cobbaert, D.; Rochefort, L.; Price, J.S. [Univ. Laval, Sainte-Foy (Canada). Dept. de Phytologie

    2004-11-01

    Methods: The effectiveness of introducing fen plants with the application of donor diaspore material was tested. The donor diaspore material, containing seeds, rhizomes, moss fragments, and other plant propagules, was collected from two different types of natural fens. We tested whether the application of straw mulch would increase fen species cover and biodiversity compared to control plots without straw mulch. Terrace levels of different peat depths (15 cm, 40 cm, and 56 cm) were created to test the effects of different environmental site conditions on the success of re-vegetation. Results: Applying donor seed bank from natural fens was found to significantly increase fen plant cover and richness after the two growing seasons. Straw mulch proved to significantly increase fen plant richness. The intermediate terrace level (40 cm) had the highest fen plant establishment. Compared to reference sites, the low terrace level (15 cm) was richer in base cations, whereas the high terrace level (56 cm) was much drier. Conclusions: The application of donor diaspore material was demonstrated as an effective technique for establishing vascular fen plants. Further rewetting measures are considered necessary at the restoration site to create a fen ecosystem rather than simply restoring some fen species (Location: Riviere-du-Loup peatland, southern Quebec, Canada at 100 m a.s.l.)

  4. Experimentation with a reverse osmosis plant powered by renewable energies

    Energy Technology Data Exchange (ETDEWEB)

    Segura, L.; Gomez, A. [Las Palmas de Gran Canaria Univ., Las Palmas (Spain). Dept. of Process Engineering; Nuez, I. [Las Palmas de Gran Canaria Univ., Las Palmas (Spain). Dept. of Electronic and Automatic Engineering

    2006-07-01

    This paper described a set of tests conducted in a reverse osmosis plant powered by renewable energy sources. Variations on feed flow, reject flow, recovery and power consumption were investigated. The plant has a production of over 115 m{sup 3} per day. During the experiments, the plant was required to operate at variable loading conditions. An energy recovery system was then developed to operate effectively with the observed variable load conditions. The system was incorporated within the reject flow system and was comprised of a Pelton turbine matched to the axis of an asynchronous energy generator. The system was designed to avoid making changes to the actual hydraulic circuit of the plant. Recovery system failures did not necessitate plant stoppages during the testing period. Simulations conducted to assess the energy system showed that optimal performance of the plant was between 16 and 18 kW with a working pressure of between 57 to 67 bars. Results also suggested that installing the system in the evacuation brine line would maximize the use of kinetic energy. It was concluded that energy recovery systems are ideal for use in seawater installations where functioning pressure levels are high. 14 refs., 1 tab., 5 figs.

  5. Model of yield response of corn to plant population and absorption of solar energy.

    Directory of Open Access Journals (Sweden)

    Allen R Overman

    Full Text Available Biomass yield of agronomic crops is influenced by a number of factors, including crop species, soil type, applied nutrients, water availability, and plant population. This article is focused on dependence of biomass yield (Mg ha(-1 and g plant(-1 on plant population (plants m(-2. Analysis includes data from the literature for three independent studies with the warm-season annual corn (Zea mays L. grown in the United States. Data are analyzed with a simple exponential mathematical model which contains two parameters, viz. Y(m (Mg ha(-1 for maximum yield at high plant population and c (m(2 plant(-1 for the population response coefficient. This analysis leads to a new parameter called characteristic plant population, x(c = 1/c (plants m(-2. The model is shown to describe the data rather well for the three field studies. In one study measurements were made of solar radiation at different positions in the plant canopy. The coefficient of absorption of solar energy was assumed to be the same as c and provided a physical basis for the exponential model. The three studies showed no definitive peak in yield with plant population, but generally exhibited asymptotic approach to maximum yield with increased plant population. Values of x(c were very similar for the three field studies with the same crop species.

  6. Experimental modeling of swirl flows in power plants

    Science.gov (United States)

    Shtork, S. I.; Litvinov, I. V.; Gesheva, E. S.; Tsoy, M. A.; Skripkin, S. G.

    2018-03-01

    The article presents an overview of the methods and approaches to experimental modeling of various thermal and hydropower units - furnaces of pulverized coal boilers and flow-through elements of hydro turbines. The presented modeling approaches based on a combination of experimentation and rapid prototyping of working parts may be useful in optimizing energy equipment to improve safety and efficiency of industrial energy systems.

  7. Nitrogen rate and plant population effects on yield and yield ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-17

    Gan et al., 2003). Nitrogen increases yield by influencing a variety of agronomic and quality parameters. In general, there was an increase in plant height and dry matter accumulation per plant in soybean (Manral and Saxena, ...

  8. Ecological context of the evolution of self-pollination in Clarkia xantiana: population size, plant communities, and reproductive assurance.

    Science.gov (United States)

    Moeller, David A; Geber, Monica A

    2005-04-01

    The repeated evolutionary transition from outcrossing to self-pollination in flowering plants has been suggested to occur because selfing provides reproductive assurance. Reports from biogeographical and ecological surveys indicate that selfing taxa are often associated with stressful and ephemeral environments, situations in which plant abundance is low (e.g., Baker's law) and with novel plant communities, however experimental tests of ecological hypotheses are few. In this study, we examined the ecological context of selection on mating system traits (herkogamy and protandry) in a California annual, Clarkia xantiana, where natural selfing populations differ from outcrossing populations in that they are often of small size or low density and occur mainly outside the range of pollinator-sharing congeners. We constructed artificial populations of plants with broad genetic variation in floral traits and manipulated two ecological factors, plant population size, and the presence versus absence of pollinator-sharing congeners, in the center of the geographic range of outcrossing populations. We found evidence for context-dependent selection on herkogamy and protandry via female fitness in which reduced traits, which promote autonomous selfing, were favored in small populations isolated from congeners whereas selection was comparatively weak in large populations or when congeners were present. In small, isolated populations, the fertility of plants with low herkogamy or protandry was elevated by 66% and 58%, respectively, compared to those with high herkogamy or protandry. The presence of pollinator-sharing congeners augmented bee visitation rates to C. xantiana flowers by 47% for all bees and by 93% for pollen specialists. By facilitating pollinator visitation, congeners mitigated selection on mating system traits in small populations, where outcross mating success is often low (the Allee effect). We also found support for the hypothesis that pollinator availability

  9. Root plasticity buffers competition among plants: theory meets experimental data.

    Science.gov (United States)

    Schiffers, Katja; Tielbörger, Katja; Tietjen, Britta; Jeltsch, Florian

    2011-03-01

    Morphological plasticity is a striking characteristic of plants in natural communities. In the context of foraging behavior particularly, root plasticity has been documented for numerous species. Root plasticity is known to mitigate competitive interactions by reducing the overlap of the individuals' rhizospheres. But despite its obvious effect on resource acquisition, plasticity has been generally neglected in previous empirical and theoretical studies estimating interaction intensity among plants. In this study, we developed a semi-mechanistic model that addresses this shortcoming by introducing the idea of compensatory growth into the classical-zone-of influence (ZOI) and field-of-neighborhood (FON) approaches. The model parameters describing the belowground plastic sphere of influence (PSI) were parameterized using data from an accompanying field experiment. Measurements of the uptake of a stable nutrient analogue at distinct distances to the neighboring plants showed that the study species responded plastically to belowground competition by avoiding overlap of individuals' rhizospheres. An unexpected finding was that the sphere of influence of the study species Bromus hordeaceus could be best described by a unimodal function of distance to the plant's center and not with a continuously decreasing function as commonly assumed. We employed the parameterized model to investigate the interplay between plasticity and two other important factors determining the intensity of competitive interactions: overall plant density and the distribution of individuals in space. The simulation results confirm that the reduction of competition intensity due to morphological plasticity strongly depends on the spatial structure of the competitive environment. We advocate the use of semi-mechanistic simulations that explicitly consider morphological plasticity to improve our mechanistic understanding of plant interactions.

  10. Modeling the growth of individuals in plant populations: local density variation in a strand population of Xanthium strumarium (Asteraceae).

    Science.gov (United States)

    Weiner, J; Kinsman, S; Williams, S

    1998-11-01

    We studied the growth of individual Xanthium strumarium plants growing at four naturally occurring local densities on a beach in Maine: (1) isolated plants, (2) pairs of plants ≤1 cm apart, (3) four plants within 4 cm of each other, and (4) discrete dense clumps of 10-39 plants. A combination of nondestructive measurements every 2 wk and parallel calibration harvests provided very good estimates of the growth in aboveground biomass of over 400 individual plants over 8 wk and afforded the opportunity to fit explicit growth models to 293 of them. There was large individual variation in growth and resultant size within the population and within all densities. Local crowding played a role in determining plant size within the population: there were significant differences in final size between all densities except pairs and quadruples, which were almost identical. Overall, plants growing at higher densities were more variable in growth and final size than plants growing at lower densities, but this was due to increased variation among groups (greater variation in local density and/or greater environmental heterogeneity), not to increased variation within groups. Thus, there was no evidence of size asymmetric competition in this population. The growth of most plants was close to exponential over the study period, but half the plants were slightly better fit by a sigmoidal (logistic) model. The proportion of plants better fit by the logistic model increased with density and with initial plant size. The use of explicit growth models over several growth intervals to describe stand development can provide more biological content and more statistical power than "growth-size" methods that analyze growth intervals separately.

  11. An experimental study for the reduction of population dose

    International Nuclear Information System (INIS)

    Muroi, Makoto

    1984-01-01

    It is a well-known fact that to reduce the amount of X-ray exposure, it is absolutely necessary to limit the field size to the minimum needed for the purpose of examination and size of the object. However, as dental X-ray apparatuses are not fitted with movable collimators, a fixed field size is applied to all exposures of intraoral radiography that is most frequently used for the dental region. Therefore, as one means of reducing the field size, the development of a changeable diaphragm for use in intraoral radiography has been undertaken. Also measurements were made of critical organ doses by field size and a nationwide survey was carried out to ascertain the frequency of intraoral radiography, through which review was made of the degree of contribution the changeable diaphragm could bring about in reducing the population dose. Much effort has led to success in the building of a changeable diaphragm into a central ray indicating cone which permits easy tube head alignment and maintenace of a set focus-skin distance. It was also found that approximately 50% of all intraoral radiography performed in Japan could have been accomplished by smaller field sizes. (author)

  12. Microbial population changes during bioremediation of an experimental oil spill

    International Nuclear Information System (INIS)

    MacNaughton, S.J.; Stephen, J.R.; Chang, Y.J.; Davis, G.A.; White, D.C.; Oak Ridge National Lab., TN

    1999-01-01

    Three crude oil bioremediation techniques were applied in a randomized block field experiment simulating a coastal oil spill. Four treatments (no oil control, oil alone, oil plus nutrients, and oil plus nutrients plus an indigenous inoculum) were applied. In situ microbial community structures were monitored by phospholipid fatty acid (PLFA) analysis and 16S rDNA PCR-denaturing gradient gel electrophoresis (DGGE) to (i) identify the bacterial community members responsible for the decontamination of the site and (ii) define an end point for the removal of the hydrocarbon substrate. The results of PLFA analysis demonstrated a community shift in all plots from primarily eukaryotic biomass to gram-negative bacterial biomass with time. PLFA profiles from the oiled plots suggested increased gram-negative biomass and adaptation to metabolic stress compared to unoiled controls. DGGE analysis of untreated control plots revealed a simple, dynamic dominant population structure throughout the experiment. This banding pattern disappeared in all oiled plots, indicating that the structure and diversity of the dominant bacterial community changed substantially. No consistent differences were detected between nutrient-amended and indigenous inoculum-treated plots, but both differed from the oil-only plots. Prominent bands were excised for sequence analysis and indicated that oil treatment encouraged the growth of gram-negative microorganisms within the α-proteobacteria and Flexibacter-Cytophaga-Bacteroides phylum. α-Proteobacteria were never detected in unoiled controls. PLFA analysis indicated that by week 14 the microbial community structures of the oiled plots were becoming similar to those of the unoiled controls from the same time point, but DGGE analysis suggested that major differences in the bacterial communities remained

  13. Medicinal plants: traditions and study prospects (devoted to the 100th anniversary of establishing the Experimental Station of Medicinal Plants

    Directory of Open Access Journals (Sweden)

    О. С. Дем’янюк

    2016-12-01

    Full Text Available Historical review was done concerning the formation and development of scientific research of the Experimental Station of Medicinal Plants over the period 1916–2016. The main stages of experimenting in the direction of “medicinal plant cultivation’’ in Ukraine were covered. Role and importance of the Experimental Station of Medicinal Plants in the scientific and methodological support of such scientific directions as breeding, seed production, cultivation technologies, pharmacognosy in medicinal plant cultivation were shown. For the needs of the branch, over 100 species of introduced medicinal plants were studied at the Station and agricultu­ral techniques of their growing were developed, in addition, more than 50 varieties of medicinal plants were crea­ted, a number of machines and devices for growing, harves­ting and initial treatment of raw materials and seeds of the most important medicinal plants was designed. Other scientific achievements of the Station were mentioned and promising areas of medicinal plant research in Ukraine were outlined.

  14. Experimental results of wind powered pumping plant with electrical transmission

    International Nuclear Information System (INIS)

    Falchetta, M.; Prischich, D.; Benedetti, A.; Cara, G.

    1992-01-01

    A demonstrative application of deep well pumping system employing a wind powered pumping plant with an electric transmission was set-up and tested for two years at the test field of the Casaccia center of ENEA (Italian Agency for Energy, New Technologies and the Environment), near Rome. The tests permitted the evaluation of the practical performance, advantages and drawbacks of a wind pumping plant of this type, in order to permit a design optimization and a proper choice of components and of control strategies for future commercial applications. The main point of investigation was the evaluation of the effectiveness of a control scheme based on a 'permanent link' between electric generator and electric motor, avoiding any electronics and switching components, and leading to a very robust and reliable means of transferring energy to the pump at variable speed, and at low cost

  15. Experimental results: Pilot plant calcine dissolution and liquid feed stability

    International Nuclear Information System (INIS)

    Herbst, R.S.; Fryer, D.S.; Brewer, K.N.; Johnson, C.K.; Todd, T.A.

    1995-02-01

    The dissolution of simulated Idaho Chemical Processing Plant pilot plant calcines, containing none of the radioactive actinides, lanthanides or fission products, was examined to evaluate the solubility of calcine matrix materials in acidic media. This study was a necessary precursor to dissolution and optimization experiments with actual radionuclide-containing calcines. The importance of temperature, nitric acid concentration, ratio of acid volume to calcine mass, and time on the amount, as a weight percentage of calcine dissolved, was evaluated. These parameters were studied for several representative pilot plant calcine types: (1) Run No. 74 Zirconia calcine; (2) Run No. 17 Zirconia/Sodium calcine; (3) Run No. 64 Zirconia/Sodium calcine; (3) Run No. 1027 Alumina calcine; and (4) Run No. 20 Alumina/Zirconia/Sodium calcine. Statistically designed experiments with the different pilot plant calcines indicated the effect of the studied process variables on the amount of calcine dissolved decreases in the order: Acid/Calcine Ratio > Temperature > HNO 3 Concentration > Dissolution Time. The following conditions are suitable to achieve greater than 90 wt. % dissolution of most Zr, Al, or Na blend calcines: (1) Maximum nitric acid concentration of 5M; (2) Minimum acid/calcine ratio of 10 mL acid/1 gram calcine; (3) Minimum dissolution temperature of 90 degrees C; and (4) Minimum dissolution time of 30 minutes. The formation of calcium sulphate (CaSO 4 ) precipitates was observed in certain dissolved calcine solutions during the dissolution experiments. Consequently, a study was initiated to evaluate if and under what conditions the resulting dissolved calcine solutions would be unstable with regards to precipitate formation. The results indicate that precipitate formation in the calcine solutions prepared under the above proposed dissolution conditions are not anticipated

  16. Experimental study on RCCV of ABWR plant-Part 1

    International Nuclear Information System (INIS)

    Saita, H.; Kikuchi, R.; Muramatsu, Y.; Hiramoto, M.; Oyamada, O.; Furukawa, H.; Sasagawa, K.; Ohmori, N.; Suzuki, S.; Suoita, M.; Kobayashi, I.; Yamaguchi, I.

    1989-01-01

    Steel containment vessels have generally been used for BWR (Boiling Water Reactor)-type nuclear power plants in Japan. However, in accordance with the development of the advanced-type BWR (ABWR), the introduction of a reinforced concrete containment vessel (RCCV) has been proposed because it enables greater freedom in flexibility of configuration. The study presented here accumulates basic data on RCCV's and verifies the integrity and ultimate strength of a trial-designed RCCV and the validity of its design method

  17. Highly Diverse Endophytic and Soil Fusarium oxysporum Populations Associated with Field-Grown Tomato Plants

    Science.gov (United States)

    Demers, Jill E.; Gugino, Beth K.

    2014-01-01

    The diversity and genetic differentiation of populations of Fusarium oxysporum associated with tomato fields, both endophytes obtained from tomato plants and isolates obtained from soil surrounding the sampled plants, were investigated. A total of 609 isolates of F. oxysporum were obtained, 295 isolates from a total of 32 asymptomatic tomato plants in two fields and 314 isolates from eight soil cores sampled from the area surrounding the plants. Included in this total were 112 isolates from the stems of all 32 plants, a niche that has not been previously included in F. oxysporum population genetics studies. Isolates were characterized using the DNA sequence of the translation elongation factor 1α gene. A diverse population of 26 sequence types was found, although two sequence types represented nearly two-thirds of the isolates studied. The sequence types were placed in different phylogenetic clades within F. oxysporum, and endophytic isolates were not monophyletic. Multiple sequence types were found in all plants, with an average of 4.2 per plant. The population compositions differed between the two fields but not between soil samples within each field. A certain degree of differentiation was observed between populations associated with different tomato cultivars, suggesting that the host genotype may affect the composition of plant-associated F. oxysporum populations. No clear patterns of genetic differentiation were observed between endophyte populations and soil populations, suggesting a lack of specialization of endophytic isolates. PMID:25304514

  18. The balance of planting and mortality in a street tree population

    Science.gov (United States)

    Lara A. Roman; John J. Battles; Joe R. McBride

    2013-01-01

    Street trees have aesthetic, environmental, human health, and economic benefits in urban ecosystems. Street tree populations are constructed by cycles of planting, growth, death, removal and replacement. The goals of this study were to understand how tree mortality and planting rates affect net population growth, evaluate the shape of the mortality curve, and assess...

  19. Competition between Plant-Populations with Different Rooting Depths. 2. Pot Experiments

    NARCIS (Netherlands)

    Berendse, F.

    1981-01-01

    In a previous paper in this series a model was proposed lor the competition between plant populations with different rooting depths. This model predicts that in mixtures of plant populations with different rooting depths the Relative Yield Total will exceed unity. Secondly it predicts that in these

  20. Solar power plant performance evaluation: simulation and experimental validation

    International Nuclear Information System (INIS)

    Natsheh, E M; Albarbar, A

    2012-01-01

    In this work the performance of solar power plant is evaluated based on a developed model comprise photovoltaic array, battery storage, controller and converters. The model is implemented using MATLAB/SIMULINK software package. Perturb and observe (P and O) algorithm is used for maximizing the generated power based on maximum power point tracker (MPPT) implementation. The outcome of the developed model are validated and supported by a case study carried out using operational 28.8kW grid-connected solar power plant located in central Manchester. Measurements were taken over 21 month's period; using hourly average irradiance and cell temperature. It was found that system degradation could be clearly monitored by determining the residual (the difference) between the output power predicted by the model and the actual measured power parameters. It was found that the residual exceeded the healthy threshold, 1.7kW, due to heavy snow in Manchester last winter. More important, the developed performance evaluation technique could be adopted to detect any other reasons that may degrade the performance of the P V panels such as shading and dirt. Repeatability and reliability of the developed system performance were validated during this period. Good agreement was achieved between the theoretical simulation and the real time measurement taken the online grid connected solar power plant.

  1. Solar power plant performance evaluation: simulation and experimental validation

    Science.gov (United States)

    Natsheh, E. M.; Albarbar, A.

    2012-05-01

    In this work the performance of solar power plant is evaluated based on a developed model comprise photovoltaic array, battery storage, controller and converters. The model is implemented using MATLAB/SIMULINK software package. Perturb and observe (P&O) algorithm is used for maximizing the generated power based on maximum power point tracker (MPPT) implementation. The outcome of the developed model are validated and supported by a case study carried out using operational 28.8kW grid-connected solar power plant located in central Manchester. Measurements were taken over 21 month's period; using hourly average irradiance and cell temperature. It was found that system degradation could be clearly monitored by determining the residual (the difference) between the output power predicted by the model and the actual measured power parameters. It was found that the residual exceeded the healthy threshold, 1.7kW, due to heavy snow in Manchester last winter. More important, the developed performance evaluation technique could be adopted to detect any other reasons that may degrade the performance of the P V panels such as shading and dirt. Repeatability and reliability of the developed system performance were validated during this period. Good agreement was achieved between the theoretical simulation and the real time measurement taken the online grid connected solar power plant.

  2. Performance of irrigated green corn cultivars in different plant populations at sowing

    Directory of Open Access Journals (Sweden)

    José C. Soares Neto

    Full Text Available ABSTRACT This study aimed to evaluate the yield of green corn hybrids grown under irrigation in different plant populations at sowing. The assay was carried out in the experimental area located in the city of Arapiraca, Alagoas State, Brazil, from November 2015 to January 2016. A randomized complete block design (RCBD was used, in a 2 x 5 factorial scheme with four replicates. A double- and a single-cross hybrid (AG 1051 and BM 3061, which are suitable for green corn production, were cultivated in five spacings between plants at sowing (15.0, 17.5, 20.0, 22.5 and 25.0 cm. The characteristics photosynthetic rate (PR, ear length with rusk (HEL and without husk (UEL, husked ear weight (HEW, unhusked ear weight (UEW, percentage of marketable ears (%ME and weight of husk (HW were evaluated. The double- and single-cross hybrids AG 1051 and BM 3061 showed green ears with commercial standard. The cultivar BM 3061 showed the best results for most of the characteristics related to the performance of green corn (PR, HEL, UEL, UEW, HEW, %ME. The spacing of 17.5 cm between plants at sowing was the most indicated for irrigated green corn cultivation.

  3. Experimentally studied laser fluorescence method for remote sensing of plant stress situation induced by improper plants watering

    Directory of Open Access Journals (Sweden)

    Yu. V. Fedotov

    2014-01-01

    Full Text Available Stressful situations of plants can be caused by a lack of nutrients; mechanical damages; diseases; low or high temperatures; lack of illumination; insufficient or excess humidity of the soil; soil salinization; soil pollution by oil products or heavy metals; the increased acidity of the soil; use of pesticides, herbicides, insecticides, etc.At early stages it is often difficult to detect seemingly that the plants are in stressful situations caused by adverse external factors. However, the fluorescent analysis potentially allows detection of the stressful situations of plants by deformation of laser-induced fluorescence spectra. The paper conducts experimental investigations to learn the capabilities of the laser fluorescent method to monitor plant situations at 532nm wavelength of fluorescence excitation in the stressful situations induced by improper watering (at excess of moisture in the soil and at a lack of moisture.Researches of fluorescence spectra have been conducted using a created laboratory installation. As a source to excite fluorescence radiation the second harmonica of YAG:Nd laser is used. The subsystem to record fluorescence radiation is designed using a polychromator and a highly sensitive matrix detector with the amplifier of brightness.Experimental investigations have been conducted for fast-growing and unpretentious species of plants, namely different sorts of salad.Experimental studies of laser-induced fluorescence spectra of plants for 532nm excitement wavelength show that the impact of stressful factors on a plant due to the improper watering, significantly distorts a fluorescence spectrum of plants. Influence of a stressful factor can be shown as a changing profile of a fluorescence spectrum (an identifying factor, here, is a relationship of fluorescence intensities at two wavelengths, namely 685 nm and 740 nm or (and as a changing level of fluorescence that can be the basis for the laser method for monitoring the plant

  4. Wild Plant Species with Extremely Small Populations Require Conservation and Reintroduction in China

    Science.gov (United States)

    Hai Ren; Qianmei Zhang; Hongfang Lu; Hongxiao Liu; Qinfeng Guo; Jun Wang; Shuguang Jian; Hai’ou Bao

    2012-01-01

    China is exceptionally rich in biodiversity, with more than 30000 vascular plant species that include many endemic genera, species of ancient origin, and cultivated plants (Yang et al. 2005). Because of rapid economic development, population growth, pollution, and continuing resource exploitation, China’s plant diversity faces severe threats. According to the Chinese...

  5. Experimental design and estimation of growth rate distributions in size-structured shrimp populations

    International Nuclear Information System (INIS)

    Banks, H T; Davis, Jimena L; Ernstberger, Stacey L; Hu, Shuhua; Artimovich, Elena; Dhar, Arun K

    2009-01-01

    We discuss inverse problem results for problems involving the estimation of probability distributions using aggregate data for growth in populations. We begin with a mathematical model describing variability in the early growth process of size-structured shrimp populations and discuss a computational methodology for the design of experiments to validate the model and estimate the growth-rate distributions in shrimp populations. Parameter-estimation findings using experimental data from experiments so designed for shrimp populations cultivated at Advanced BioNutrition Corporation are presented, illustrating the usefulness of mathematical and statistical modeling in understanding the uncertainty in the growth dynamics of such populations

  6. International Thermonuclear Experimental Reactor (ITER) plant layout and site services

    International Nuclear Information System (INIS)

    Chuyanov, V.

    2001-01-01

    The ITER site has not been determined at this time. Nevertheless, to develop a construction plan and a cost estimate, it is necessary to have a detailed layout of the buildings, structures, and outdoor equipment integrated with the balance of plant service systems prototypical of large fusion power plants. These services include electric power for magnet feeds and plasma heating systems, cryogenic and conventional cooling systems, compressed air, gas supplies, de-mineralized water, steam, and drainage. Nuclear grade facilities are provided to handle tritium fuel and activated waste, as well as to prevent radioactive exposure of either the workers or the public. To avoid interference between services of different types and for efficient arrangement of buildings, structures, and equipment within the site area, a plan was developed which segregated different classes of services to four quadrants surrounding the tokamak building, placed at the approximate geographic center of the site. Location of the twenty-seven buildings on the generic site was selected to meet all design requirements at minimum total project cost. A similar approach has been used to determine the location of services above, at, and below grade. The generic site plan can be adapted to the site selected for ITER without significant changes to the buildings or equipment. Some rearrangements may be required by site topography resulting primarily in changes to the length of services that link the buildings and equipment. (author)

  7. Experimental thermal behavior of a power plant reheater

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, M. Manuela Prieto; Garcia, F. Javier Fernandez; Ramon, Ines Suarez [Departamento de Energia, Universidad de Oviedo, Campus de Viesques, 33204 Gijon, Asturias (Spain); Roces, Hilario Sanchez [Central Termica de Soto de Ribera, Soto de Ribera, Asturias (Spain)

    2006-04-15

    The process conditions of power plant components subjected to high pressures and temperatures are essential to determine their remaining life, availability and efficiency. It is, therefore, expedient to pay special attention to critical components, such as superheater and reheater heat exchangers, headers, and main and reheated steam lines. In this paper, on-line and off-line variables of a power plant reheater that has presented problems of thickness losses and repetitive tube fissures are studied. The fissures are associated with the effect of a thermal-mechanical mechanism. Off-line measurements were taken of the following variables: pressure, temperature, velocity and composition of the gases. On-line instrumentation was completed by the installation of specific thermocouples to ascertain the temperatures in the tubes outlet. Various angles for the fuel inlet of the burners and variations in the number and location of the working burners were also assayed. As a consequence of this analysis, it can be deduced that there are important differences in the outlet temperature of the reheater tubes that decrease for lower powers. Finally, it is pointed that a non-uniform distribution of the steam flow in the reheater might be the cause of the problem. (author)

  8. International Thermonuclear Experimental Reactor (ITER) plant layout and site services

    International Nuclear Information System (INIS)

    Chuyanov, V.

    1999-01-01

    The ITER site has not been determined at this time. Nevertheless, to develop a construction plan and a cost estimate, it is necessary to have a detailed layout of the buildings, structures, and outdoor equipment integrated with the balance of plant service systems prototypical of large fusion power plants. These services include electric power for magnet feeds and plasma heating systems, cryogenic and conventional cooling systems, compressed air, gas supplies, de-mineralized water, steam, and drainage. Nuclear grade facilities are provided to handle tritium fuel and activated waste, as well as to prevent radioactive exposure of either the workers or the public. To avoid interference between services of different types and for efficient arrangement of buildings, structures, and equipment within the site area, a plan was developed which segregated different classes of services to four quadrants surrounding the tokamak building, placed at the approximate geographic center of the site. Location of the twenty-seven buildings on the generic site was selected to meet all design requirements at minimum total project cost. A similar approach has been used to determine the location of services above, at, and below grade. The generic site plan can be adapted to the site selected for ITER without significant changes to the buildings or equipment. Some rearrangements may be required by site topography resulting primarily in changes to the length of services that link the buildings and equipment. (author)

  9. Retrieval of canistered experimental waste at the waste isolation pilot plant

    International Nuclear Information System (INIS)

    Stinebaugh, R.E.

    1979-07-01

    To assess the suitability of bedded salt for nuclear waste disposal, an extensive experimental program will be implemented at the Waste Isolation Pilot Plant. In order to evaluate experimental results, it will be necessary to recover certain of these experiments for postmortem examination and analysis. This document describes the equipment and procedures used to effect recovery of one category of WIPP experiments

  10. Impact of tillage, plant population and mulches on phenological characters of maize

    International Nuclear Information System (INIS)

    Gul, B.; Khan, M.A.; Khan, H.

    2014-01-01

    Field experiments were conducted during 2006 and 2007 in Peshawar, using open pollinated maize variety Azam in RCB design having 3 factors viz., tillage, maize populations and mulches with split-split plot arrangements. Tillage levels (zero and conventional) were assigned to the main plots, populations (90000, 60000 and 30000 plants ha/sup -1/) to sub-plots and four types of mulches (weeds mulch, black plastic mulch, white plastic mulch and mungbean as living mulch), a hand weeding and a weedy check were allotted to sub-sub plots, respectively. Data were recorded on days to tasseling, days to silking, days to maturity, leaf area of maize plant-1 (cm/sub 2/) and plant height (cm). Tillage affected leaf area of maize, where zero tillage resulted lower leaf area of 4094 cm/sub 2/ compared to conventional tillage (4722 cm/sub 2/). Different levels of plant populations affected all the physiological parameters. Days to tasseling, silking and maturity were more in higher plant population as compared to medium and lower plant population. Similarly, minimum leaf area plant-1 was recorded in higher plant population (3894 cm/sub 2/) than medium and lower plant population of 4398 and 4932 cm/sub 2/, respectively. Maximum plant height was recorded in hand weeding treatment (173 cm). However, it was statistically at par with black plastic mulch (171 cm), followed by weeds mulch (162 cm) and white plastic mulch (161 cm) as compared to weedy check (152 cm). Based on two years study it is suggested that even if tillage options and plant populations are a part of the weed management program, it should not be used as a sole management tool, as both have a negative impact on the phenological parameters of maize which subsequently affected the final yield and must be integrated and supplemented with other control methods. (author)

  11. Experimental biogas power plant at STU in bratislava

    International Nuclear Information System (INIS)

    Pipa, M.; Kment, A.; Janicek, F.

    2012-01-01

    Slovak University of Technology in Bratislava builds the technological research and development center financed by the Structural Funds of the European Union focused on use of different energy sources. In terms of renewable energy is discussed use of biomass energy available through biogas technology with a dry fermentation process. This is a pilot project of experimental physical model, which will be attempting to verify and optimize the pre-project phase parameters and technology already in commercial projects in scaled-down model. The paper deals with the design of this device. (Authors)

  12. Site selection and evaluation for nuclear power plants with respect to population distribution

    International Nuclear Information System (INIS)

    1980-01-01

    This safety guide, relating population distribution to site selection and evaluation, for nuclear power plants, forms part of the IAEA's programme, referred to as the NUSS programme (Nuclear Safety Standards). The guide presents population distribution data, requirements, examples of site screening methods, and an overview of radiological impact assessment with respect to population distribution

  13. Live Fast, Die Young: Experimental Evidence of Population Extinction Risk due to Climate Change

    Science.gov (United States)

    Bestion, Elvire; Teyssier, Aimeric; Richard, Murielle; Clobert, Jean; Cote, Julien

    2015-01-01

    Evidence has accumulated in recent decades on the drastic impact of climate change on biodiversity. Warming temperatures have induced changes in species physiology, phenology, and have decreased body size. Such modifications can impact population dynamics and could lead to changes in life cycle and demography. More specifically, conceptual frameworks predict that global warming will severely threaten tropical ectotherms while temperate ectotherms should resist or even benefit from higher temperatures. However, experimental studies measuring the impacts of future warming trends on temperate ectotherms' life cycle and population persistence are lacking. Here we investigate the impacts of future climates on a model vertebrate ectotherm species using a large-scale warming experiment. We manipulated climatic conditions in 18 seminatural populations over two years to obtain a present climate treatment and a warm climate treatment matching IPCC predictions for future climate. Warmer temperatures caused a faster body growth, an earlier reproductive onset, and an increased voltinism, leading to a highly accelerated life cycle but also to a decrease in adult survival. A matrix population model predicts that warm climate populations in our experiment should go extinct in around 20 y. Comparing our experimental climatic conditions to conditions encountered by populations across Europe, we suggest that warming climates should threaten a significant number of populations at the southern range of the distribution. Our findings stress the importance of experimental approaches on the entire life cycle to more accurately predict population and species persistence in future climates. PMID:26501958

  14. The demographic consequences of mutualism: ants increase host-plant fruit production but not population growth.

    Science.gov (United States)

    Ford, Kevin R; Ness, Joshua H; Bronstein, Judith L; Morris, William F

    2015-10-01

    The impact of mutualists on a partner's demography depends on how they affect the partner's multiple vital rates and how those vital rates, in turn, affect population growth. However, mutualism studies rarely measure effects on multiple vital rates or integrate them to assess the ultimate impact on population growth. We used vital rate data, population models and simulations of long-term population dynamics to quantify the demographic impact of a guild of ant species on the plant Ferocactus wislizeni. The ants feed at the plant's extrafloral nectaries and attack herbivores attempting to consume reproductive organs. Ant-guarded plants produced significantly more fruit, but ants had no significant effect on individual growth or survival. After integrating ant effects across these vital rates, we found that projected population growth was not significantly different between unguarded and ant-guarded plants because population growth was only weakly influenced by differences in fruit production (though strongly influenced by differences in individual growth and survival). However, simulations showed that ants could positively affect long-term plant population dynamics through services provided during rare but important events (herbivore outbreaks that reduce survival or years of high seedling recruitment associated with abundant precipitation). Thus, in this seemingly clear example of mutualism, the interaction may actually yield no clear benefit to plant population growth, or if it does, may only do so through the actions of the ants during rare events. These insights demonstrate the value of taking a demographic approach to studying the consequences of mutualism.

  15. Ability of matrix models to explain the past and predict the future of plant populations.

    Science.gov (United States)

    McEachern, Kathryn; Crone, Elizabeth E.; Ellis, Martha M.; Morris, William F.; Stanley, Amanda; Bell, Timothy; Bierzychudek, Paulette; Ehrlen, Johan; Kaye, Thomas N.; Knight, Tiffany M.; Lesica, Peter; Oostermeijer, Gerard; Quintana-Ascencio, Pedro F.; Ticktin, Tamara; Valverde, Teresa; Williams, Jennifer I.; Doak, Daniel F.; Ganesan, Rengaian; Thorpe, Andrea S.; Menges, Eric S.

    2013-01-01

    Uncertainty associated with ecological forecasts has long been recognized, but forecast accuracy is rarely quantified. We evaluated how well data on 82 populations of 20 species of plants spanning 3 continents explained and predicted plant population dynamics. We parameterized stage-based matrix models with demographic data from individually marked plants and determined how well these models forecast population sizes observed at least 5 years into the future. Simple demographic models forecasted population dynamics poorly; only 40% of observed population sizes fell within our forecasts' 95% confidence limits. However, these models explained population dynamics during the years in which data were collected; observed changes in population size during the data-collection period were strongly positively correlated with population growth rate. Thus, these models are at least a sound way to quantify population status. Poor forecasts were not associated with the number of individual plants or years of data. We tested whether vital rates were density dependent and found both positive and negative density dependence. However, density dependence was not associated with forecast error. Forecast error was significantly associated with environmental differences between the data collection and forecast periods. To forecast population fates, more detailed models, such as those that project how environments are likely to change and how these changes will affect population dynamics, may be needed. Such detailed models are not always feasible. Thus, it may be wiser to make risk-averse decisions than to expect precise forecasts from models.

  16. Ability of matrix models to explain the past and predict the future of plant populations.

    Science.gov (United States)

    Crone, Elizabeth E; Ellis, Martha M; Morris, William F; Stanley, Amanda; Bell, Timothy; Bierzychudek, Paulette; Ehrlén, Johan; Kaye, Thomas N; Knight, Tiffany M; Lesica, Peter; Oostermeijer, Gerard; Quintana-Ascencio, Pedro F; Ticktin, Tamara; Valverde, Teresa; Williams, Jennifer L; Doak, Daniel F; Ganesan, Rengaian; McEachern, Kathyrn; Thorpe, Andrea S; Menges, Eric S

    2013-10-01

    Uncertainty associated with ecological forecasts has long been recognized, but forecast accuracy is rarely quantified. We evaluated how well data on 82 populations of 20 species of plants spanning 3 continents explained and predicted plant population dynamics. We parameterized stage-based matrix models with demographic data from individually marked plants and determined how well these models forecast population sizes observed at least 5 years into the future. Simple demographic models forecasted population dynamics poorly; only 40% of observed population sizes fell within our forecasts' 95% confidence limits. However, these models explained population dynamics during the years in which data were collected; observed changes in population size during the data-collection period were strongly positively correlated with population growth rate. Thus, these models are at least a sound way to quantify population status. Poor forecasts were not associated with the number of individual plants or years of data. We tested whether vital rates were density dependent and found both positive and negative density dependence. However, density dependence was not associated with forecast error. Forecast error was significantly associated with environmental differences between the data collection and forecast periods. To forecast population fates, more detailed models, such as those that project how environments are likely to change and how these changes will affect population dynamics, may be needed. Such detailed models are not always feasible. Thus, it may be wiser to make risk-averse decisions than to expect precise forecasts from models. © 2013 Society for Conservation Biology.

  17. Socio environmental policy and populational resettlement in hydropower plants

    International Nuclear Information System (INIS)

    Regini Nuti, Mirian; Feitosa Garcia, Marcia

    2003-01-01

    This paper aims to discuss the resettlement process caused by hydropower plants considering the Brazilian Power Sector ongoing context It is based on the analysis of the hydropower plants that started operation phase in the last tem years There are 17 projects provoking the displacement of 21000 families The paper presents the resettlement modalities used in these projects Finally, the main aspects of the resettlement process in the last decade are focused in order to contribute to the Brazilian Power Sector Resettlement Guidelines improvement and actualization

  18. Basic versus applied research: Julius Sachs (1832-1897) and the experimental physiology of plants.

    Science.gov (United States)

    Kutschera, Ulrich

    2015-01-01

    The German biologist Julius Sachs was the first to introduce controlled, accurate, quantitative experimentation into the botanical sciences, and is regarded as the founder of modern plant physiology. His seminal monograph Experimental-Physiologie der Pflanzen (Experimental Physiology of Plants) was published 150 y ago (1865), when Sachs was employed as a lecturer at the Agricultural Academy in Poppelsdorf/Bonn (now part of the University). This book marks the beginning of a new era of basic and applied plant science. In this contribution, I summarize the achievements of Sachs and outline his lasting legacy. In addition, I show that Sachs was one of the first biologists who integrated bacteria, which he considered to be descendants of fungi, into the botanical sciences and discussed their interaction with land plants (degradation of wood etc.). This "plant-microbe-view" of green organisms was extended and elaborated by the laboratory botanist Wilhelm Pfeffer (1845-1920), so that the term "Sachs-Pfeffer-Principle of Experimental Plant Research" appears to be appropriate to characterize this novel way of performing scientific studies on green, photoautotrophic organisms (embryophytes, algae, cyanobacteria).

  19. Plant extracts, metaldehyde and saline solutions on the population control of Bradybaena similaris

    Directory of Open Access Journals (Sweden)

    Junir Antonio Lutinski

    2016-08-01

    Full Text Available ABSTRACT: This study aimed to test the efficiency of plant extracts, metaldehyde and saline solutions, as alternatives to the population control of the snail Bradybaena similaris , and to investigate the effect of the plant extracts in reducing the damage of the snail on Brassica oleracea . The experiments were performed at the Entomology Laboratory of the Universidade Comunitária da Região de Chapecó (Unochapecó, using a random experimental design with nine treatments in triplicate. Five adult individuals of B. similaris were subjected to each trial, totaling 135 snails. The following treatments were tested: cinnamon ( Melia azedarach , timbó ( Ateleia glazioveana , rosemary ( Rosmarinus officinalis , mate herb ( Ilex paraguariensis , two concentrations of metaldehyde (3% and 5%, two concentrations of salt solution (5% and 10 %, and a control treatment (distilled water. To evaluate the survival of B. similaris it was checked the treatments every 24 hours, over four consecutive days. The results revealed that the two concentrations of metaldehyde were fully efficient, that the saline solution (10% had and intermediate efficiency, and that all other treatments were not effective. The treatment with the M. azedarach extract induced a higher consumption of B. oleracea , while the saline solution at 10% and the extracts of R. officinalis and I. paraguariensis inhibited leaf consumption.

  20. Effect of plant populations on the productivity of plantain and ...

    African Journals Online (AJOL)

    Two plantain-cassava intercropping experiments were conducted at the Teaching and Research Farm of Obafemi Awolowo University, Ile–Ife. Each experiment was planted in a 2 x 2 factorial involving four mixture proportions arranged in Randomized Complete Block design with four replications. Growth, crop yields and ...

  1. Plant functional traits as determinants of population stability

    Czech Academy of Sciences Publication Activity Database

    Májeková, M.; de Bello, Francesco; Doležal, Jiří; Lepš, Jan

    2014-01-01

    Roč. 95, č. 9 (2014), s. 2369-2374 ISSN 0012-9658 R&D Projects: GA ČR GA13-17118S Institutional support: RVO:67985939 ; RVO:60077344 Keywords : biomass * fertilizaiton * plant functional traits Subject RIV: EH - Ecology, Behaviour Impact factor: 4.656, year: 2014

  2. 78 FR 7890 - Endangered and Threatened Wildlife and Plants; Establishment of a Nonessential Experimental...

    Science.gov (United States)

    2013-02-04

    ... experimental population (including eggs, propagules, or individuals) of an endangered or threatened species... possible adverse effects on extant populations of a species as a result of removal of individuals, eggs, or...; Tomasik and Cook 2005, p. 390; Cegelski et al. 2006, p. 206; Aubry et al. 2011, pp. 21-22; Inman et al...

  3. 78 FR 4813 - Endangered and Threatened Wildlife and Plants; Establishment of a Nonessential Experimental...

    Science.gov (United States)

    2013-01-23

    .... Before authorizing the release as an experimental population of any population (including eggs... removal of individuals, eggs, or propagules for introduction elsewhere; (2) the likelihood that any such... introduction of orangespotted sunfish (Cook 2011, pers. comm.). Topeka shiners feed primarily on insects, such...

  4. The Genetic Basis of Plant Architecture in 10 Maize Recombinant Inbred Line Populations.

    Science.gov (United States)

    Pan, Qingchun; Xu, Yuancheng; Li, Kun; Peng, Yong; Zhan, Wei; Li, Wenqiang; Li, Lin; Yan, Jianbing

    2017-10-01

    Plant architecture is a key factor affecting planting density and grain yield in maize ( Zea mays ). However, the genetic mechanisms underlying plant architecture in diverse genetic backgrounds have not been fully addressed. Here, we performed a large-scale phenotyping of 10 plant architecture-related traits and dissected the genetic loci controlling these traits in 10 recombinant inbred line populations derived from 14 diverse genetic backgrounds. Nearly 800 quantitative trait loci (QTLs) with major and minor effects were identified as contributing to the phenotypic variation of plant architecture-related traits. Ninety-two percent of these QTLs were detected in only one population, confirming the diverse genetic backgrounds of the mapping populations and the prevalence of rare alleles in maize. The numbers and effects of QTLs are positively associated with the phenotypic variation in the population, which, in turn, correlates positively with parental phenotypic and genetic variations. A large proportion (38.5%) of QTLs was associated with at least two traits, suggestive of the frequent occurrence of pleiotropic loci or closely linked loci. Key developmental genes, which previously were shown to affect plant architecture in mutant studies, were found to colocalize with many QTLs. Five QTLs were further validated using the segregating populations developed from residual heterozygous lines present in the recombinant inbred line populations. Additionally, one new plant height QTL, qPH3 , has been fine-mapped to a 600-kb genomic region where three candidate genes are located. These results provide insights into the genetic mechanisms controlling plant architecture and will benefit the selection of ideal plant architecture in maize breeding. © 2017 American Society of Plant Biologists. All Rights Reserved.

  5. Using soil seed banks to assess temporal patterns of genetic variation in invasive plant populations

    OpenAIRE

    Fennell, Mark; Gallagher, Tommy; Vintro, Luis Leon; Osborne, Bruce

    2014-01-01

    Most research on the genetics of invasive plant species has focused on analyzing spatial differences among existing populations. Using a long-established Gunnera tinctoria population from Ireland, we evaluated the potential of using plants derived from seeds associated with different soil layers to track genetic variation through time. This species and site were chosen because (1) G. tinctoria produces a large and persistent seed bank; (2) it has been present in this locality, Sraheens, for ∼...

  6. Diversity reduces invasibility in experimental plant communities: the role of plant species

    NARCIS (Netherlands)

    Van Ruijven, J.; De Deyn, G.B.; Berendse, F.

    2003-01-01

    Several studies have presented experimental evidence that diversity reduces invasibility in grassland communities. The interpretation of these results has been disputed recently and it was proposed that sampling effects were responsible for the observed decrease of invasibility with diversity. The

  7. Methods and benefits of experimental seismic evaluation of nuclear power plants. Final report

    International Nuclear Information System (INIS)

    1979-07-01

    This study reviews experimental techniques, instrumentation requirements, safety considerations, and benefits of performing vibration tests on nuclear power plant containments and internal components. The emphasis is on testing to improve seismic structural models. Techniques for identification of resonant frequencies, damping, and mode shapes, are discussed. The benefits of testing with regard to increased damping and more accurate computer models are oulined. A test plan, schedule and budget are presented for a typical PWR nuclear power plant

  8. Modelling and Experimental Investigation of Unsteady Behaviour of a Screw Compressor Plant

    OpenAIRE

    Chukanova, Ekatarina; Stosic, Nikola; Kovacevic, Ahmed

    2014-01-01

    Majority of air compressor plants installed worldwide operate permanently under unsteady conditions, however, there is still a lack of published papers which describe the plant dynamics and offer quantification parameters of the phenomenon. An experimental and analytical study of a screw compressor operation under unsteady conditions has been carried out. For this purpose a one dimensional model of the processes within a screw compressor based on the differential equations of conservation of ...

  9. Methods and benefits of experimental seismic evaluation of nuclear power plants. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1979-07-01

    This study reviews experimental techniques, instrumentation requirements, safety considerations, and benefits of performing vibration tests on nuclear power plant containments and internal components. The emphasis is on testing to improve seismic structural models. Techniques for identification of resonant frequencies, damping, and mode shapes, are discussed. The benefits of testing with regard to increased damping and more accurate computer models are oulined. A test plan, schedule and budget are presented for a typical PWR nuclear power plant.

  10. Competition between Plant-Populations with Different Rooting Depths. 1. Theoretical Considerations

    NARCIS (Netherlands)

    Berendse, F.

    1979-01-01

    As an extension of De Wit's competition theory a theoretical description has been developed of competition between plant populations with different rooting depths. This model shows that in mixtures of plants with different rooting depths the value of the Relative Yield Total can be expected to

  11. Competition Between Plant Populations with Different Rooting Depths I. Theoretical Considerations

    NARCIS (Netherlands)

    Berendse, Frank

    1979-01-01

    As an extension of De Wit’s competition theory a theoretical description has been developed of competition between plant populations with different rooting depths. This model shows that in mixtures of plants with different rooting depths the value of the Relative Yield Total can be expected to

  12. Occupational hazard evaluation of working population in a select automotive industrial plant.

    Science.gov (United States)

    Wójcik, Alicja; Borzecki, Zdzisław; Kowalska, Edyta; Borzecki, Andrzej

    2004-01-01

    The research was conducted in the selected vehicle industry plant. Work conditions were assessed on the assembly line by measuring chemical and physical factors. Exposure to noise in the investigated plant exceeded the values of permissible standards. The pollution on the posts did not exceed the standards except singular concentrations. While assessing the values of chemical factors concentration, no toxicological danger was revealed in the investigated population. The work conditions of the investigated plant did not create the danger of professional diseases.

  13. An experimental study on mass loading of soil particles on plant surfaces

    International Nuclear Information System (INIS)

    Li, J. G.; Gerzabek, M. H.; Mueck, K.

    1994-01-01

    Radionuclide contaminated soil adhered to plant surfaces can contribute to human ingestion dose. To determine this contribution, a method of 46 Sc neutron activation analysis was established and tested, by which a detection limit of 0.05 mg soil per g dry plant biomass can be obtained. In the field and greenhouse experiment the mass loading of soil on ryegrass (Lolium perenne L.) and broadbean (Vicia faba L.) was investigated and the contribution from rainsplash and wind erosion were evaluated separately. Soil retained on plant surfaces in field conditions in Seibersdorf/Austria was 5.77 ± 1.44 mg soil per g dry plant for ryegrass and 9.51 ± 0.73 mg soil per g dry plant for broadbean. Estimates of contribution from rainsplash and wind erosion to soil contamination of plants during the experimental period are 68 % and 32 % for broadbean 47 % and 53 % for ryegrass respectively. Mass loading results from field studies indicate that soil adhesion on plant surfaces can contribute up to 23 % of plant 137 Cs contamination, the transfer factors modified by mass loading decline differently, depending on 137 Cs concentration of the soil and the soil mass adhered to plant surfaces. (author)

  14. An experimental study on mass loading of soil particles on plant surfaces

    International Nuclear Information System (INIS)

    Li, J.; Gerzabek, M.H.; Mueck, K.

    1994-03-01

    Radionuclide contaminated soil adhered to plant surfaces can contribute to human ingestion dose. To determine this contribution, a method of 46 Sc neutron activation analysis was established and tested, by which a detection limit of 0.05 mg soil per g dry plant biomass can be obtained. In the field and greenhouse experiment the mass loading of soil on ryegrass (Lolium perenne L.) and broad bean (Vicia faba L.) was investigated and the contribution from rainsplash and wind erosion were evaluated separately. Soil retained on plant surfaces in field conditions in Seibersdorf/Austria was 5.77 ± 1.44 mg soil per g dry plant for ryegrass and 9.51 ± 0.73 mg soil per g dry plant for broad bean. Estimates of contribution from rainsplash and wind erosion to soil contamination of plant during the experimental period are 68 % and 32 % for broadbean, 47 % and 53 % for ryegrass, respectively. Mass loading results from field studies indicate that soil adhesion on plant surfaces can contribute up to 23 % of plant 137 Cs contamination, the transfer factors modified by mass loading decline differently, depending on 137 Cs concentration of the soil and the soil mass adhered to plant surfaces. (authors)

  15. Assessing the impact of power plant mortality on the compensatory reserve of fish populations

    International Nuclear Information System (INIS)

    Goodyear, C.P.

    1977-01-01

    A technique is presented to quantify the concepts of compensation and compensatory reserve in exploited fish populations. The technique was used to examine the impact of power plant mortality on a hypothetical striped bass population. Power plant mortality had a more severe impact on the compensation ratio and compensatory reserve for an exploited stock. The technique can be applied to determine a critical compensation ratio which could serve as a standard against which additional sources of mortality, such as those caused by power plants, could be measured

  16. Baselines to detect population stability of the threatened alpine plant Packera franciscana (Asteraceae)

    Science.gov (United States)

    James F. Fowler; Carolyn Hull Sieg; Shaula Hedwall

    2015-01-01

    Population size and density estimates have traditionally been acceptable ways to track species’ response to changing environments; however, species' population centroid elevation has recently been an equally important metric. Packera franciscana (Greene) W.A. Weber and A. Love (Asteraceae; San Francisco Peaks ragwort) is a single mountain endemic plant found only...

  17. Interactions between fluvial forces and vegetation size, density and morphology influence plant mortality during experimental floods

    Science.gov (United States)

    Stella, J. C.; Kui, L.; Manners, R.; Wilcox, A. C.; Lightbody, A.; Sklar, L. S.

    2015-12-01

    Introduction and methods Fluvial disturbance is a key driver of riparian vegetation dynamics in river corridors. Despite an increasing understanding of ecohydraulic interactions between plants and fluvial forces, the interactive influences of plant morphology and sediment supply on plant mortality, a key demographic factor, are largely unknown. To better understand these processes, we designed and conducted a series of flume experiments to: (1) quantify effects of plant traits that interact with flow and sediment transport on plant loss to scour during floods; and (2) predict plant dislodgement for different species across a range of plant sizes, patch densities, and sediment condition (equilibrium transport versus sediment deficit). We ran ten experimental floods in a 28 m long × 0.6 m wide × 0.71 m tall flume, using live, 1-3 year-old tamarisk and cottonwood seedlings with contrasting morphologies with varied combinations of size and density. Results and discussion Both sediment supply and plant traits (morphology and composition) have significant impacts on plant vulnerability during floods. Sediment deficit resulted in bed degradation and a 35% greater risk of plant loss compared to equilibrium sediment conditions. The probability of plant dislodgement in sparse patches was 4.5 times greater than in dense patches. Tamarisk plants and patches had greater frontal area, basal diameter and longer roots compared to cottonwood across all seedling heights. These traits, as well as its lower crown position reduced tamarisk's vulnerability to scour by 75%. Compared with cottonwood, tamarisk exhibits better resistance to floods, due to its greater root biomass and longer roots that stabilize soil, and its greater frontal area and lower crown that effectively trap sediment. These traits likely contribute to riverscape-scale changes in channel morphology that are evident where tamarisk has invaded native riparian communities, and explain the persistence of tamarisk

  18. Population-based resequencing of experimentally evolved populations reveals the genetic basis of body size variation in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Thomas L Turner

    2011-03-01

    Full Text Available Body size is a classic quantitative trait with evolutionarily significant variation within many species. Locating the alleles responsible for this variation would help understand the maintenance of variation in body size in particular, as well as quantitative traits in general. However, successful genome-wide association of genotype and phenotype may require very large sample sizes if alleles have low population frequencies or modest effects. As a complementary approach, we propose that population-based resequencing of experimentally evolved populations allows for considerable power to map functional variation. Here, we use this technique to investigate the genetic basis of natural variation in body size in Drosophila melanogaster. Significant differentiation of hundreds of loci in replicate selection populations supports the hypothesis that the genetic basis of body size variation is very polygenic in D. melanogaster. Significantly differentiated variants are limited to single genes at some loci, allowing precise hypotheses to be formed regarding causal polymorphisms, while other significant regions are large and contain many genes. By using significantly associated polymorphisms as a priori candidates in follow-up studies, these data are expected to provide considerable power to determine the genetic basis of natural variation in body size.

  19. Experimental estimation of mutation rates in a wheat population with a gene genealogy approach.

    Science.gov (United States)

    Raquin, Anne-Laure; Depaulis, Frantz; Lambert, Amaury; Galic, Nathalie; Brabant, Philippe; Goldringer, Isabelle

    2008-08-01

    Microsatellite markers are extensively used to evaluate genetic diversity in natural or experimental evolving populations. Their high degree of polymorphism reflects their high mutation rates. Estimates of the mutation rates are therefore necessary when characterizing diversity in populations. As a complement to the classical experimental designs, we propose to use experimental populations, where the initial state is entirely known and some intermediate states have been thoroughly surveyed, thus providing a short timescale estimation together with a large number of cumulated meioses. In this article, we derived four original gene genealogy-based methods to assess mutation rates with limited bias due to relevant model assumptions incorporating the initial state, the number of new alleles, and the genetic effective population size. We studied the evolution of genetic diversity at 21 microsatellite markers, after 15 generations in an experimental wheat population. Compared to the parents, 23 new alleles were found in generation 15 at 9 of the 21 loci studied. We provide evidence that they arose by mutation. Corresponding estimates of the mutation rates ranged from 0 to 4.97 x 10(-3) per generation (i.e., year). Sequences of several alleles revealed that length polymorphism was only due to variation in the core of the microsatellite. Among different microsatellite characteristics, both the motif repeat number and an independent estimation of the Nei diversity were correlated with the novel diversity. Despite a reduced genetic effective size, global diversity at microsatellite markers increased in this population, suggesting that microsatellite diversity should be used with caution as an indicator in biodiversity conservation issues.

  20. Relative population exposures from coal-fired and nuclear power plants in India

    Energy Technology Data Exchange (ETDEWEB)

    Ramachandran, T.V.; Lalit, B.Y.; Mishra, U.C.

    1987-01-01

    Coal combustion for electric power generation results in dispersal of fly ash, and hence an additional radiation dose to the population living in the neighbourhood of the coal-fired power plants due to natural radioactivity present in coal. The radiation hazards of coal based and nuclear power plants operating in India are given. The dose commitments to the population living within an 88.5 km radius of the thermal and nuclear power plants in India have been computed using the method outlined in an ORNL report. The estimated dose rates for these two types of power plant were compared. The present study shows that the radiation dose from coal-fired and nuclear power plants are comparable.

  1. Drying and purification of natural gas by clinoptilolite on an experimental pilot plant

    Energy Technology Data Exchange (ETDEWEB)

    Tsitsishvili, G V; Urotadze, S L; Lukin, V D; Bagirov, R M

    1976-02-01

    The paper deals with the process of the drying and purification of natural gas from CO/sub 2/ on an experimental pilot plant using the natural zeolite clinoptilolite. On the basis of the obtained data the dynamic activity of clinoptilolite against water and CO/sub 2/ has been calculated.

  2. RNA Isolation from Plant Tissues: A Hands-On Laboratory Experimental Experience for Undergraduates

    Science.gov (United States)

    Zhang, Nianhui; Yu, Dong; Zhu, Xiaofeng

    2018-01-01

    The practice of RNA isolation in undergraduate experimental courses is rare because of the existence of robust, ubiquitous and stable ribonucleases. We reported here modifications to our original protocol for RNA isolation from plant tissues, including the recovery of nucleic acids by ethanol precipitation at 0 degrees C for 10 min and the…

  3. Effect of plant-animal interactions on individual performance and population dynamics of Scorzonera hispanica

    OpenAIRE

    Červenková, Zita

    2016-01-01

    The population dynamics of plants with regard to plant-animal interactions is a remarkably complex topic. To look into how individual life stages are influenced in different directions by various animals is beyond the scope of a single paper. For each of the studies described below, I and my co-authors attempted to collect data that would cover as much of the plant life cycle as possible, focusing on interactions between plants and different animals during the flowering period and their conse...

  4. Siting of nuclear power plants in densely populated countries

    International Nuclear Information System (INIS)

    Togo, Y.

    1981-01-01

    In evaluating the safety of reactor siting, three typical approaches can be applied; the deterministic approach, the probabilistic approach and the combined approach. In regard to a risk associated with siting, the design of a reactor has to do with both individual and societal risk, while exclusion distance mainly has to do with individual risk, and surrounding population primarily has to do with societal risk. Consequently, in a densely populated area, more attention should be paid to societal risk. There are many reactor sites in the world which can be described as concentrated siting. Although concentrated siting has a lot of merits, such as reducing the construction cost or maintenance cost of reactors, more careful consideration should be paid to safety-related matters of such concentrated reactors because the risk to the individual from accidents caused by concentrated reactors is larger than that from a single reactor. As for the recent controversial issue concerning siting criteria, it appears that the present international consensus on siting philosophy is still valid after the TMI accident. (author)

  5. Experimental investigation into the seismic behavior of nuclear power plant shear wall structures

    International Nuclear Information System (INIS)

    Kenneally, R.M.; Burns, J.J. Jr.

    1988-01-01

    Nuclear power plant structures are designed to resist large earthquakes. However, as new data are obtained on earthquake activity throughout the United States, plant design earthquake levels have increased. The U.S. Nuclear Regulatory Commission is sponsoring an analytical-experimental research program to obtain information on the strucutral response of nuclear power plant shear wall strucutres subjected to earthquake motions within and beyond their design basis. Using different size scale models constructed with microconcrete and prototypical concrete this research has demonstrated consistent results for measured values of stiffness at load levels within the design basis. Furthermore, the values are well below the theoretical stiffnesses calculated from an uncracked cross-section strength-of-materials approach. Current program emphasis is to assess the credibility of previous experimental work by beginning to resolve the 'stiffness difference' issue. (orig.)

  6. Experimental study on the operators' cognitive behavior analysis for the plant anomaly diagnosis

    International Nuclear Information System (INIS)

    Takahashi, Makoto; Kubo, Osamu; Yasuta, Akira

    1996-01-01

    In this paper, a method of human cognitive state estimation based on physiological measures has been applied to the analysis of cognitive behavior during anomaly diagnosis observed with nuclear power plant simulator. This method has also been combined with the conventional experimental protocol such as operational sequence and questionnaire results. The simulator experiments have been performed using plant experts and the results demonstrate that the cognitive state estimation method can be an effective way for understanding cognitive behavior during the anomaly diagnosis of the nuclear power plant. It has also been shown from the results that the combined use of the human cognitive state estimation and the conventional experimental protocol can provide effective information in decreasing the ambiguity of the analysis results. (author)

  7. AKUT-II: an experimental plant for purifying the HTR loop of combustion waste gas

    Energy Technology Data Exchange (ETDEWEB)

    Beaujean, H.; Vygen, H.

    1976-02-15

    A plant for the separation of aerosols, krypton and tritium (AKUT) used for purifying the head end of the reprocessing of thorium-containing fuel elements from combustion waste gases is described. Data are to be collected to enable a process engineer to plan and construct a large-scale plant, and the correctness and practicability of the concept adopted is to be proved in conjunction with the JUPITER plant. It is true that the tests on the AKUT I plant confirmed that the flow scheme was basically correct, but the actual experimental operation was considerably limited by a fixed and rigid coupling to the combustion furnace. Some operational conditions were encountered which did not meet the design values. Part of the plant (krypton separation) is being tested in the USA. The German concept was taken over in the early stages of tests and adapted to existing apparatuses, the result inevitably being different experimental conditions. The AKUT II plant can now be used for consideration of the economic and safety conditions, and comparisons can be made.

  8. Insect herbivores drive real-time ecological and evolutionary change in plant populations.

    Science.gov (United States)

    Agrawal, Anurag A; Hastings, Amy P; Johnson, Marc T J; Maron, John L; Salminen, Juha-Pekka

    2012-10-05

    Insect herbivores are hypothesized to be major factors affecting the ecology and evolution of plants. We tested this prediction by suppressing insects in replicated field populations of a native plant, Oenothera biennis, which reduced seed predation, altered interspecific competitive dynamics, and resulted in rapid evolutionary divergence. Comparative genotyping and phenotyping of nearly 12,000 O. biennis individuals revealed that in plots protected from insects, resistance to herbivores declined through time owing to changes in flowering time and lower defensive ellagitannins in fruits, whereas plant competitive ability increased. This independent real-time evolution of plant resistance and competitive ability in the field resulted from the relaxation of direct selective effects of insects on plant defense and through indirect effects due to reduced herbivory on plant competitors.

  9. Purple pitcher plant (Sarracenia rosea Dieback and partial community disassembly following experimental storm surge in a coastal pitcher plant bog.

    Directory of Open Access Journals (Sweden)

    Matthew J Abbott

    Full Text Available Sea-level rise and frequent intense hurricanes associated with climate change will result in recurrent flooding of inland systems such as Gulf Coastal pitcher plant bogs by storm surges. These surges can transport salt water and sediment to freshwater bogs, greatly affecting their biological integrity. Purple pitcher plants (Sarracenia rosea are Gulf Coast pitcher plant bog inhabitants that could be at a disadvantage under this scenario because their pitcher morphology may leave them prone to collection of saline water and sediment after a surge. We investigated the effects of storm surge water salinity and sediment type on S. rosea vitality, plant community structure, and bog soil-water conductivity. Plots (containing ≥1 ramet of S. rosea were experimentally flooded with fresh or saline water crossed with one of three sediment types (local, foreign, or no sediment. There were no treatment effects on soil-water conductivity; nevertheless, direct exposure to saline water resulted in significantly lower S. rosea cover until the following season when a prescribed fire and regional drought contributed to the decline of all the S. rosea to near zero percent cover. There were also significant differences in plant community structure between treatments over time, reflecting how numerous species increased in abundance and a few species decreased in abundance. However, in contrast to S. rosea, most of the other species in the community appeared resilient to the effects of storm surge. Thus, although the community may be somewhat affected by storm surge, those few species that are particularly sensitive to the storm surge disturbance will likely drop out of the community and be replaced by more resilient species. Depending on the longevity of these biological legacies, Gulf Coastal pitcher plant bogs may be incapable of fully recovering if they become exposed to storm surge more frequently due to climate change.

  10. Anomalous dependence of population growth on the birth rate in the plant-herbivore system

    International Nuclear Information System (INIS)

    Cui, Xue M.; Han, Seung K.; Chung, Jean S.

    2010-01-01

    We performed a simulation of the two-species plant-herbivore system by using the agent-based NetLogo program and constructed a dynamic model of populations consistent with the simulation results. The dynamic model is a three-dimensional system including the mean energy of the herbivore in addition to two variables denoting the populations of plants and herbivores. A steady-state analysis of the dynamic model shows that the dependence of the herbivore population on the birth and the death rates observed from the agent model is consistent with the prediction of the dynamic model. Especially, the anomalous dependence of the herbivore population on the birth rate, where the population decreases with the birth rate for small death rate, is consistently explained by a phase plane analysis of the dynamic model.

  11. Genotypic and phenotypic diversity in populations of plant-probiotic Pseudomonas spp. colonizing roots

    Science.gov (United States)

    Picard, Christine; Bosco, Marco

    2008-01-01

    Several soil microorganisms colonizing roots are known to naturally promote the health of plants by controlling a range of plant pathogens, including bacteria, fungi, and nematodes. The use of theses antagonistic microorganisms, recently named plant-probiotics, to control plant-pathogenic fungi is receiving increasing attention, as they may represent a sustainable alternative to chemical pesticides. Many years of research on plant-probiotic microorganisms (PPM) have indicated that fluorescent pseudomonads producing antimicrobial compounds are largely involved in the suppression of the most widespread soilborne pathogens. Phenotype and genotype analysis of plant-probiotic fluorescent pseudomonads (PFP) have shown considerable genetic variation among these types of strains. Such variability plays an important role in the rhizosphere competence and the biocontrol ability of PFP strains. Understanding the mechanisms by which genotypic and phenotypic diversity occurs in natural populations of PFP could be exploited to choose those agricultural practices which best exploit the indigenous PFP populations, or to isolate new plant-probiotic strains for using them as inoculants. A number of different methods have been used to study diversity within PFP populations. Because different resolutions of the existing microbial diversity can be revealed depending on the approach used, this review first describes the most important methods used for the assessment of fluorescent Pseudomonas diversity. Then, we focus on recent data relating how differences in genotypic and phenotypic diversity within PFP communities can be attributed to geographic location, climate, soil type, soil management regime, and interactions with other soil microorganisms and host plants. It becomes evident that plant-related parameters exert the strongest influence on the genotypic and phenotypic variations in PFP populations.

  12. Long term growth of crop plants on experimental plots created among slag heaps.

    Science.gov (United States)

    Halecki, Wiktor; Klatka, Sławomir

    2018-01-01

    Suppression of plant growth is a common problem in post-mining reclaimed areas, as coarse texture of soils may increase nitrate leaching. Assessing feasibility of using solid waste (precipitated solid matter) produced by water and sewage treatment processes in field conditions is very important in mine soil reclamation. Our work investigated the possibility of plant growth in a degraded site covered with sewage-derived sludge material. A test area (21m × 18m) was established on a mine soil heap. Experimental plant species included Camelina sativa, Helianthus annuus, Festuca rubra, Miscanthus giganteus, Amaranthus cruentus, Brassica napus, Melilotus albus, Beta vulgaris, and Zea mays. ANOVA showed sufficient water content and acceptable physical properties of the soil in each year and layer in a multi-year period, indicating that these species were suitable for phytoremediation purposes. Results of trace elements assays indicated low degree of contamination caused by Carbocrash waste material and low potential ecological risk for all plant species. Detrended correspondence analysis revealed that total porosity and capillary porosity were the most important variables for the biosolids among all water content related properties. Overall, crop plants were found useful on heavily degraded land and the soil benefited from their presence. An addition of Carbocrash substrate to mine soil improved the initial stage of soil reclamation and accelerated plant growth. The use of this substrate in phytoremediation helped to balance the content of nutrients, promoted plant growth, and increased plant tolerance to salinity. Sewage sludge-amended biosolids may be applied directly to agricultural soil, not only in experimental conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Use of plants in oral health care by the population of Mahajanga, Madagascar.

    Science.gov (United States)

    Ranjarisoa, Lala Nirina; Razanamihaja, Noëline; Rafatro, Herintsoa

    2016-12-04

    The use of medicinal plants to address oral health problems is not well documented in Madagascar, yet the country is full of endemic flora. The aim of this study was to collect information on the use of plants in the region of Mahajanga, Madagascar, for the treatments of oral diseases mainly tooth decay. The ethnobotanical survey with respect to the use of plants for curing dental problems was carried out in 2012. A cluster sampling at three levels was applied when choosing the study sites. The target population was made up of heads of household. The following data were collected from a semi-structured questionnaire: name of plants, part used, mode of preparation, and administration. The Informant Consensus Factor and Fidelity Level indexes were calculated for each condition treated and used plants. The Results revealed that 93 per cent of the targeted population has used plants to calm dental pain, whereas 44.2% have reported using plants due to financial problems. About 65 species of plants are commonly used for oral health care and 63 of them treated caries. Cajanus cajan (L.) Millsp. was the most plant used. It was mostly used in crushed form of 5 to 9 leaves which were prepared and placed directly on the affected oral part or in the tooth cavity. In general, the treatment lasted about 5 days or minus. The ICF were 0.83 for caries and 0.81 for periodontal diseases. This ethnobotanical survey will serve as database for further phytochemical and pharmacological study of plants in order to identify their active components and advise the population on the most effective administration. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  14. Alarming plant dieback in the Outeniquas : is this an indication of global warming? Monitoring plant populations

    CSIR Research Space (South Africa)

    Rebelo, T

    2009-03-01

    Full Text Available for the Outeniquas do predict increased precipitation in summer. But we don’t know. Only in 20 years will we be able to look back and decide. At this stage it is safer to claim that the plants responded markedly to the exceptional weather conditions. Whether... these weather conditions are indicative of climate changes to come only time will tell. But it is only by documenting the responses of plants to these extreme events that we will get a clear idea of what might happen as our climate changes. Then we...

  15. Nuclear power plant site evaluation using site population-meterology factor

    International Nuclear Information System (INIS)

    Rho, B.H.; Kang, C.H.

    1982-01-01

    In this paper, as a site evaluation technique, SPNF(Site Population Neteorology Factor) which is modified from SPF(Site Population Factor) of the USNRC model, is defined from site population and meteorology data in order to consider the radiological impacts to the population at large from the atmospheric dispersion of the radioactive effluents released during routine plant operation as well as accidental conditions. The SPMF model proved its propriety from the comparison of SPMF and SPF for Kori site. The relative suitability of Korean sites to the U.S. sites have been also examined using SPF. (Author)

  16. Experimental evolution and the dynamics of adaptation and genome evolution in microbial populations.

    Science.gov (United States)

    Lenski, Richard E

    2017-10-01

    Evolution is an on-going process, and it can be studied experimentally in organisms with rapid generations. My team has maintained 12 populations of Escherichia coli in a simple laboratory environment for >25 years and 60 000 generations. We have quantified the dynamics of adaptation by natural selection, seen some of the populations diverge into stably coexisting ecotypes, described changes in the bacteria's mutation rate, observed the new ability to exploit a previously untapped carbon source, characterized the dynamics of genome evolution and used parallel evolution to identify the genetic targets of selection. I discuss what the future might hold for this particular experiment, briefly highlight some other microbial evolution experiments and suggest how the fields of experimental evolution and microbial ecology might intersect going forward.

  17. Experimental evidence of population differences in reproductive investment conditional on environmental stochasticity

    Energy Technology Data Exchange (ETDEWEB)

    Gauthey, Zoé [INRA, UMR 1224, Ecologie Comportementale et Biologie des Populations de Poissons, Aquapôle, quartier Ibarron, 64310 Saint-Pée sur Nivelle (France); Univ Pau & Pays Adour, UMR 1224, Ecologie Comportementale et Biologie des Populations de Poissons, UFR Sciences et Techniques de la Côte Basque, Allée du parc Montaury, 64600 Anglet (France); Panserat, Stéphane [INRA, UR 107, Nutrition Metabolism Aquaculture, Aquapôle, 64310 Saint Pée sur Nivelle (France); Elosegi, Arturo [Faculty of Science and Technology, University of the Basque Country UPV/EHU, 48080 Bilbao (Spain); Herman, Alexandre [INRA, UR 107, Nutrition Metabolism Aquaculture, Aquapôle, 64310 Saint Pée sur Nivelle (France); Tentelier, Cédric [INRA, UMR 1224, Ecologie Comportementale et Biologie des Populations de Poissons, Aquapôle, quartier Ibarron, 64310 Saint-Pée sur Nivelle (France); Univ Pau & Pays Adour, UMR 1224, Ecologie Comportementale et Biologie des Populations de Poissons, UFR Sciences et Techniques de la Côte Basque, Allée du parc Montaury, 64600 Anglet (France); and others

    2016-01-15

    Environmental stochasticity is expected to shape life histories of species, wherein organisms subjected to strong environmental variation should display adaptive response by being able to tune their reproductive investment. For riverine ecosystems, climate models forecast an increase in the frequency and intensity of extreme events such as floods and droughts. The speed and the mechanisms by which organisms may adapt their reproductive investment are therefore of primary importance to understand how species will cope with such radical environmental changes. In the present study, we sampled spawners from two different populations of wild brown trout, originating from two environments with contrasting levels of flow stochasticity. We placed them in sympatry within an experimental channel during reproductive season. In one modality, water flow was maintained constant, whereas in another modality, water flow was highly variable. Reproductive investment of all individuals was monitored using weight and energetic plasma metabolite variation throughout the reproductive season. Only the populations originating from the most variable environment showed a plastic response to experimental manipulation of water flow, the females being able to reduce their weight variation (from 19.2% to 13.1%) and metabolites variations (from 84.2% to 18.6% for triglycerides for instance) under variable flow conditions. These results imply that mechanisms to cope with environmental stochasticity can differ between populations of the same species, where some populations can be plastic whereas other cannot. - Highlights: • We place two populations of brown trout under contrasting water flow for reproduction. • Energetic metabolite variation is used as a cue of reproductive investment. • In constant flow, both populations show the same reproductive investment. • In variable flow, only one of the populations modifies its reproductive investment. • Divergent evolution of reproductive

  18. Experimental evidence of population differences in reproductive investment conditional on environmental stochasticity

    International Nuclear Information System (INIS)

    Gauthey, Zoé; Panserat, Stéphane; Elosegi, Arturo; Herman, Alexandre; Tentelier, Cédric

    2016-01-01

    Environmental stochasticity is expected to shape life histories of species, wherein organisms subjected to strong environmental variation should display adaptive response by being able to tune their reproductive investment. For riverine ecosystems, climate models forecast an increase in the frequency and intensity of extreme events such as floods and droughts. The speed and the mechanisms by which organisms may adapt their reproductive investment are therefore of primary importance to understand how species will cope with such radical environmental changes. In the present study, we sampled spawners from two different populations of wild brown trout, originating from two environments with contrasting levels of flow stochasticity. We placed them in sympatry within an experimental channel during reproductive season. In one modality, water flow was maintained constant, whereas in another modality, water flow was highly variable. Reproductive investment of all individuals was monitored using weight and energetic plasma metabolite variation throughout the reproductive season. Only the populations originating from the most variable environment showed a plastic response to experimental manipulation of water flow, the females being able to reduce their weight variation (from 19.2% to 13.1%) and metabolites variations (from 84.2% to 18.6% for triglycerides for instance) under variable flow conditions. These results imply that mechanisms to cope with environmental stochasticity can differ between populations of the same species, where some populations can be plastic whereas other cannot. - Highlights: • We place two populations of brown trout under contrasting water flow for reproduction. • Energetic metabolite variation is used as a cue of reproductive investment. • In constant flow, both populations show the same reproductive investment. • In variable flow, only one of the populations modifies its reproductive investment. • Divergent evolution of reproductive

  19. How to conserve threatened Chinese plant species with extremely small populations?

    Directory of Open Access Journals (Sweden)

    Sergei Volis

    2016-02-01

    Full Text Available The Chinese flora occupies a unique position in global plant diversity, but is severely threatened. Although biodiversity conservation in China has made significant progress over the past decades, many wild plant species have extremely small population sizes and therefore are in extreme danger of extinction. The concept of plant species with extremely small populations (PSESPs, recently adopted and widely accepted in China, lacks a detailed description of the methodology appropriate for conserving PSESPs. Strategies for seed sampling, reintroduction, protecting PSESP locations, managing interactions with the local human population, and other conservation aspects can substantially differ from those commonly applied to non-PSESPs. The present review is an attempt to provide a detailed conservation methodology with realistic and easy-to-follow guidelines for PSESPs in China.

  20. Herbivory and growth in terrestrial and aquatic populations of amphibious stream plants

    DEFF Research Database (Denmark)

    Sand-Jensen, Kaj; Jacobsen, Dean

    2002-01-01

    1. Many amphibious plant species grow in the transition between terrestrial and submerged vegetation in small lowland streams. We determined biomass development, leaf turnover rate and invertebrate herbivory during summer in terrestrial and aquatic populations of three amphibious species...... production (average 1.2-5.1%) than aquatic populations (2.9-17.3%), while the same plant dry mass was consumed per unit ground area. 3. Grazing loss increased linearly with leaf age apart from the youngest leaf stages. Grazing loss during the lifetime of leaves was therefore 2.4-3.1 times higher than mean...... apparent loss to standing leaves of all ages. The results imply that variation in density of grazers relative to plant production can account for differences in grazing impact between terrestrial and aquatic populations, and that fast leaf turnover keeps apparent grazing damage down. 4. We conclude...

  1. Experimental study on the plant state estimation for the condition-based maintenance

    International Nuclear Information System (INIS)

    Harada, J. I.; Takahashi, M.; Kitamura, M.; Wakabayashi, T.

    2006-01-01

    A framework of maintenance support system based on the plant state estimation using diverse methods has been proposed and the validity of the plant state estimation methods has been experimentally evaluated. The focus has been set on the construction of the BN for the objective system with the scale and complexity as same as real world systems. Another focus has been set on the other functions for maintenance support system such as signal processing tool and similarity matching. The validity of the proposed inference method has been confirmed through numerical experiments. (authors)

  2. Waste Isolation Pilot Plant transuranic wastes experimental characterization program: executive summary

    International Nuclear Information System (INIS)

    Molecke, M.A.

    1978-11-01

    A general overview of the Waste Isolation Pilot Plant transuranic wastes experimental characterization program is presented. Objectives and outstanding concerns of this program are discussed. Characteristics of transuranic wastes are also described. Concerns for the terminal isolation of such wastes in a deep bedded salt facility are divided into two phases, those during the short-term operational phase of the facility, and those potentially occurring in the long-term, after decommissioning of the repository. An inclusive summary covering individual studies, their importance to the Waste Isolation Pilot Plant, investigators, general milestones, and comments are presented

  3. Population dynamics of bacteria involved in enhanced biological phosphorus removal in Danish wastewater treatment plants.

    Science.gov (United States)

    Mielczarek, Artur Tomasz; Nguyen, Hien Thi Thu; Nielsen, Jeppe Lund; Nielsen, Per Halkjær

    2013-03-15

    The enhanced biological phosphorus removal (EBPR) process is increasingly popular as a sustainable method for removal of phosphorus (P) from wastewater. This study consisted of a comprehensive three-year investigation of the identity and population dynamics of polyphosphate-accumulating organisms (PAOs) and glycogen-accumulating organisms (GAOs) in 28 Danish municipal wastewater treatment plants with nutrient removal. Fluorescence in situ hybridization was applied to quantify ten probe-defined populations of PAO and GAO that in total constituted a large fraction (30% on average) of the entire microbial community targeted by the EUBmix probes. Two PAO genera, Accumulibacter and Tetrasphaera, were very abundant in all EBPR plants (average of 3.7% and 27% of all bacteria, respectively), and their abundance was relatively stable in the Danish full-scale plants without clear temporal variations. GAOs were occasionally present in some plants (Competibacter in 11 plants, Defluviicoccus in 6 plants) and were consistent in only a few plants. This shows that these were not core species in the EBPR communities. The total GAO abundance was always lower than that of Accumulibacter. In plants without EBPR design, the abundance of PAO and GAO was significantly lower. Competibacter correlated in general with high fraction of industrial wastewater. In specific plants Accumulibacter correlated with high C/P ratio of the wastewater and Tetrasphaera with high organic loading. Interestingly, the relative microbial composition of the PAO/GAO species was unique to each plant over time, which gives a characteristic plant-specific "fingerprint". Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Host plant use drives genetic differentiation in syntopic populations of Maculinea alcon

    DEFF Research Database (Denmark)

    Tartally, András; Kelager, Andreas; Fürst, Matthias Alois

    2016-01-01

    The rare socially parasitic butterfly Maculinea alcon occurs in two forms, which are characteristic of hygric or xeric habitats and which exploit different host plants and host ants. The status of these two forms has been the subject of considerable controversy. Populations of the two forms...... on different host plants, each with a distinct flowering phenology, providing a temporal rather than spatial barrier to gene flow....

  5. Population genetic analysis reveals barriers and corridors for gene flow within and among riparian populations of a rare plant.

    Science.gov (United States)

    Hevroy, Tanya H; Moody, Michael L; Krauss, Siegfried L

    2018-02-01

    Landscape features and life-history traits affect gene flow, migration and drift to impact on spatial genetic structure of species. Understanding this is important for managing genetic diversity of threatened species. This study assessed the spatial genetic structure of the rare riparian Grevillea sp. Cooljarloo (Proteaceae), which is restricted to a 20 km 2 region impacted by mining in the northern sandplains of the Southwest Australian Floristic Region, an international biodiversity hotspot. Within creek lines and floodplains, the distribution is largely continuous. Models of dispersal within riparian systems were assessed by spatial genetic analyses including population level partitioning of genetic variation and individual Bayesian clustering. High levels of genetic variation and weak isolation by distance within creek line and floodplain populations suggest large effective population sizes and strong connectivity, with little evidence for unidirectional gene flow as might be expected from hydrochory. Regional clustering of creek line populations and strong divergence among creek line populations suggest substantially lower levels of gene flow among creek lines than within creek lines. There was however a surprising amount of genetic admixture in floodplain populations, which could be explained by irregular flooding and/or movements by highly mobile nectar-feeding bird pollinators. Our results highlight that for conservation of rare riparian species, avoiding an impact to hydrodynamic processes, such as water tables and flooding dynamics, may be just as critical as avoiding direct impacts on the number of plants.

  6. Conservation state of populations of rare plant species in highly transformed meadow steppes of Southern Opillya

    Directory of Open Access Journals (Sweden)

    I. I. Dmytrash-Vatseba

    2016-09-01

    Full Text Available Degradation of natural habitats causes rapid extinction of rare plant populations. The diversity of rare plant species in the meadow steppes of Southern Opillya (Western Ukraine depends strongly on patch area, pasture digression of vegetation and a variety of eco-coenotical conditions. The main threats for the rare components of the meadow steppe flora are reduction of habitat and overgrazing. Spatial connections between sites are unable to support a constant rare plant population. The analysis of the composition of rare plant meadow-steppe species indicated that habitats with similar rare species composition usually have similar parameters of area, stages of pasture digression and eco-coenotical conditions. Spatial connectivity of patches does not ensure species similarity of rare components of the flora. Rare plant species were grouped according to their preferences for habitat , area and condition. In small patches subject to any stage of pasture digression grow populations of Adonis vernalis L., Pulsatilla patens (L. Mill., P. grandis Wender., Stipa capillata L., S. рennata L., Chamaecytisus blockianus (Pawł. Klásková etc. On the contrary, populations of other species (Carlina onopordifolia Besser. ex Szafer., Kuecz. et Pawł., Adenophora liliifolia (L. Ledeb. ex A. DC., Crambe tataria Sebeók, Euphorbia volhynica Besser ex Racib., Stipa tirsa Stev. etc. prefer large habitats, not changed by pasture digression. Prevention of reduction of rare species diversity requires preservation (also extension of patch area and regulation of grazing intensity.

  7. Experimental Manipulation of Grassland Plant Diversity Induces Complex Shifts in Aboveground Arthropod Diversity

    Science.gov (United States)

    Hertzog, Lionel R.; Meyer, Sebastian T.; Weisser, Wolfgang W.; Ebeling, Anne

    2016-01-01

    Changes in producer diversity cause multiple changes in consumer communities through various mechanisms. However, past analyses investigating the relationship between plant diversity and arthropod consumers focused only on few aspects of arthropod diversity, e.g. species richness and abundance. Yet, shifts in understudied facets of arthropod diversity like relative abundances or species dominance may have strong effects on arthropod-mediated ecosystem functions. Here we analyze the relationship between plant species richness and arthropod diversity using four complementary diversity indices, namely: abundance, species richness, evenness (equitability of the abundance distribution) and dominance (relative abundance of the dominant species). Along an experimental gradient of plant species richness (1, 2, 4, 8, 16 and 60 plant species), we sampled herbivorous and carnivorous arthropods using pitfall traps and suction sampling during a whole vegetation period. We tested whether plant species richness affects consumer diversity directly (i), or indirectly through increased productivity (ii). Further, we tested the impact of plant community composition on arthropod diversity by testing for the effects of plant functional groups (iii). Abundance and species richness of both herbivores and carnivores increased with increasing plant species richness, but the underlying mechanisms differed between the two trophic groups. While higher species richness in herbivores was caused by an increase in resource diversity, carnivore richness was driven by plant productivity. Evenness of herbivore communities did not change along the gradient in plant species richness, whereas evenness of carnivores declined. The abundance of dominant herbivore species showed no response to changes in plant species richness, but the dominant carnivores were more abundant in species-rich plant communities. The functional composition of plant communities had small impacts on herbivore communities, whereas

  8. Experimental Manipulation of Grassland Plant Diversity Induces Complex Shifts in Aboveground Arthropod Diversity.

    Science.gov (United States)

    Hertzog, Lionel R; Meyer, Sebastian T; Weisser, Wolfgang W; Ebeling, Anne

    2016-01-01

    Changes in producer diversity cause multiple changes in consumer communities through various mechanisms. However, past analyses investigating the relationship between plant diversity and arthropod consumers focused only on few aspects of arthropod diversity, e.g. species richness and abundance. Yet, shifts in understudied facets of arthropod diversity like relative abundances or species dominance may have strong effects on arthropod-mediated ecosystem functions. Here we analyze the relationship between plant species richness and arthropod diversity using four complementary diversity indices, namely: abundance, species richness, evenness (equitability of the abundance distribution) and dominance (relative abundance of the dominant species). Along an experimental gradient of plant species richness (1, 2, 4, 8, 16 and 60 plant species), we sampled herbivorous and carnivorous arthropods using pitfall traps and suction sampling during a whole vegetation period. We tested whether plant species richness affects consumer diversity directly (i), or indirectly through increased productivity (ii). Further, we tested the impact of plant community composition on arthropod diversity by testing for the effects of plant functional groups (iii). Abundance and species richness of both herbivores and carnivores increased with increasing plant species richness, but the underlying mechanisms differed between the two trophic groups. While higher species richness in herbivores was caused by an increase in resource diversity, carnivore richness was driven by plant productivity. Evenness of herbivore communities did not change along the gradient in plant species richness, whereas evenness of carnivores declined. The abundance of dominant herbivore species showed no response to changes in plant species richness, but the dominant carnivores were more abundant in species-rich plant communities. The functional composition of plant communities had small impacts on herbivore communities, whereas

  9. Demographics of an experimentally released population of elk in Great Smoky Mountains National Park

    Science.gov (United States)

    Murrow, Jennifer L.; Clark, Joseph D.; Delozier, E. Kim

    2009-01-01

    We assessed the potential for reestablishing elk (Cervus elaphus) in Great Smoky Mountains National Park (GSMNP), USA, by estimating vital rates of experimentally released animals from 2001 to 2006. Annual survival rates for calves ranged from 0.333 to 1.0 and averaged 0.592. Annual survival for subadult and adult elk (i.e., ≥1 yr of age) ranged from 0.690 to 0.933, depending on age and sex. We used those and other vital rates to model projected population growth and viability using a stochastic individual-based model. The annual growth rate (λ) of the modeled population over a 25-year period averaged 0.996 and declined from 1.059 the first year to 0.990 at year 25. The modeled population failed to attain a positive 25-year mean growth rate in 46.0% of the projections. Poor calf recruitment was an important determinant of low population growth. Predation by black bears (Ursus americanus) was the dominant calf mortality factor. Most of the variance of growth projections was due to demographic variation resulting from the small population size (n  =  61). Management actions such as predator control may help increase calf recruitment, but our projections suggest that the GSMNP elk population may be at risk for some time because of high demographic variation.

  10. Experimental tests for heritable morphological color plasticity in non-native brown trout (Salmo trutta populations.

    Directory of Open Access Journals (Sweden)

    Peter A H Westley

    Full Text Available The success of invasive species is frequently attributed to phenotypic plasticity, which facilitates persistence in novel environments. Here we report on experimental tests to determine whether the intensity of cryptic coloration patterns in a global invader (brown trout, Salmo trutta was primarily the result of plasticity or heritable variation. Juvenile F1 offspring were created through experimental crosses of wild-caught parents and reared for 30 days in the laboratory in a split-brood design on either light or dark-colored gravel substrate. Skin and fin coloration quantified with digital photography and image analysis indicated strong plastic effects in response to substrate color; individuals reared on dark substrate had both darker melanin-based skin color and carotenoid-based fin colors than other members of their population reared on light substrate. Slopes of skin and fin color reaction norms were parallel between environments, which is not consistent with heritable population-level plasticity to substrate color. Similarly, we observed weak differences in population-level color within an environment, again suggesting little genetic control on the intensity of skin and fin colors. Taken as whole, our results are consistent with the hypothesis that phenotypic plasticity may have facilitated the success of brown trout invasions and suggests that plasticity is the most likely explanation for the variation in color intensity observed among these populations in nature.

  11. An experimental field study of delayed density dependence in natural populations of Aedes albopictus.

    Directory of Open Access Journals (Sweden)

    Rachael K Walsh

    Full Text Available Aedes albopictus, a species known to transmit dengue and chikungunya viruses, is primarily a container-inhabiting mosquito. The potential for pathogen transmission by Ae. albopictus has increased our need to understand its ecology and population dynamics. Two parameters that we know little about are the impact of direct density-dependence and delayed density-dependence in the larval stage. The present study uses a manipulative experimental design, under field conditions, to understand the impact of delayed density dependence in a natural population of Ae. albopictus in Raleigh, North Carolina. Twenty liter buckets, divided in half prior to experimentation, placed in the field accumulated rainwater and detritus, providing oviposition and larval production sites for natural populations of Ae. albopictus. Two treatments, a larvae present and larvae absent treatment, were produced in each bucket. After five weeks all larvae were removed from both treatments and the buckets were covered with fine mesh cloth. Equal numbers of first instars were added to both treatments in every bucket. Pupae were collected daily and adults were frozen as they emerged. We found a significant impact of delayed density-dependence on larval survival, development time and adult body size in containers with high larval densities. Our results indicate that delayed density-dependence will have negative impacts on the mosquito population when larval densities are high enough to deplete accessible nutrients faster than the rate of natural food accumulation.

  12. Nitrogen and plant population change radiation capture and utilization capacity of sunflower in semi-arid environment.

    Science.gov (United States)

    Awais, Muhammad; Wajid, Aftab; Bashir, Muhammad Usman; Habib-Ur-Rahman, Muhammad; Raza, Muhammad Aown Sammar; Ahmad, Ashfaq; Saleem, Muhammad Farrukh; Hammad, Hafiz Mohkum; Mubeen, Muhammad; Saeed, Umer; Arshad, Muhammad Naveed; Fahad, Shah; Nasim, Wajid

    2017-07-01

    The combination of nitrogen and plant population expresses the spatial distribution of crop plants. The spatial distribution influences canopy structure and development, radiation capture, accumulated intercepted radiation (Sa), radiation use efficiency (RUE), and subsequently dry matter production. We hypothesized that the sunflower crop at higher plant populations and nitrogen (N) rates would achieve early canopy cover, capture more radiant energy, utilize radiation energy more efficiently, and ultimately increase economic yield. To investigate the above hypothesis, we examined the influences of leaf area index (LAI) at different plant populations (83,333, 66,666, and 55,555 plants ha -1 ) and N rates (90, 120, and 150 kg ha -1 ) on radiation interception (Fi), photosynthetically active radiation (PAR) accumulation (Sa), total dry matter (TDM), achene yield (AY), and RUE of sunflower. The experimental work was conducted during 2012 and 2013 on sandy loam soil in Punjab, Pakistan. The sunflower crop captured more than 96% of incident radiant energy (mean of all treatments), 98% with a higher plant population (83,333 plants ha -1 ), and 97% with higher N application (150 kg ha -1 ) at the fifth harvest (60 days after sowing) during both study years. The plant population of 83,333 plants ha -1 with 150 kg N ha -1 ominously promoted crop, RUE, and finally productivity of sunflower (AY and TDM). Sunflower canopy (LAI) showed a very close and strong association with Fi (R 2  = 0.99 in both years), PAR (R 2  = 0.74 and 0.79 in 2012 and 2013, respectively), TDM (R 2  = 0.97 in 2012 and 0.91 in 2013), AY (R 2  = 0.95 in both years), RUE for TDM (RUE TDM ) (R 2  = 0.63 and 0.71 in 2012 and 2013, respectively), and RUE for AY (RUE AY ) (R 2  = 0.88 and 0.87 in 2012 and 2013, respectively). Similarly, AY (R 2  = 0.73 in 2012 and 0.79 in 2013) and TDM (R 2  = 0.75 in 2012 and 0.84 in 2013) indicated significant dependence on PAR accumulation of

  13. Lead and zinc accumulation and tolerance in populations of six wetland plants

    Energy Technology Data Exchange (ETDEWEB)

    Deng, H. [Biology Department and Croucher Institute for Environmental Sciences, Hong Kong Baptist University, Kowloon, Hong Kong (China); Department of Environmental Science and Technology, East China Normal University, Shanghai (China); Ye, Z.H. [Biology Department and Croucher Institute for Environmental Sciences, Hong Kong Baptist University, Kowloon, Hong Kong (China); School of Life Sciences, Zhongshan (Sun Yat-sen) University, Guangzhou 510275 (China); Wong, M.H. [Biology Department and Croucher Institute for Environmental Sciences, Hong Kong Baptist University, Kowloon, Hong Kong (China)]. E-mail: mhwong@hkbu.edu.hk

    2006-05-15

    Wetland plants such as Typha latifolia and Phragmites australis have been indicated to show a lack of evolution of metal tolerance in metal-contaminated populations. The aim of the present study is to verify whether other common wetland plants such as Alternanthera philoxeroides and Beckmannia syzigachne, also possess the same characteristics. Lead and zinc tolerances in populations of six species collected from contaminated and clean sites were examined by hydroponics. In general, the contaminated populations did not show higher metal tolerance and accumulation than the controls. Similar growth responses and tolerance indices in the same metal treatment solution between contaminated and control populations suggest that metal tolerance in wetland plants are generally not further evolved by contaminated environment. The reasons may be related to the special root anatomy in wetland plants, the alleviated metal toxicity by the reduced rooting conditions and the relatively high innate metal tolerance in some species. - Populations from metal contaminated sites did not have significantly higher metal tolerance indices.

  14. Lead and zinc accumulation and tolerance in populations of six wetland plants

    International Nuclear Information System (INIS)

    Deng, H.; Ye, Z.H.; Wong, M.H.

    2006-01-01

    Wetland plants such as Typha latifolia and Phragmites australis have been indicated to show a lack of evolution of metal tolerance in metal-contaminated populations. The aim of the present study is to verify whether other common wetland plants such as Alternanthera philoxeroides and Beckmannia syzigachne, also possess the same characteristics. Lead and zinc tolerances in populations of six species collected from contaminated and clean sites were examined by hydroponics. In general, the contaminated populations did not show higher metal tolerance and accumulation than the controls. Similar growth responses and tolerance indices in the same metal treatment solution between contaminated and control populations suggest that metal tolerance in wetland plants are generally not further evolved by contaminated environment. The reasons may be related to the special root anatomy in wetland plants, the alleviated metal toxicity by the reduced rooting conditions and the relatively high innate metal tolerance in some species. - Populations from metal contaminated sites did not have significantly higher metal tolerance indices

  15. Effects of long-term chronic exposure to radionuclides in plant populations

    International Nuclear Information System (INIS)

    Geras'kin, S.; Evseeva, T.; Oudalova, A.

    2013-01-01

    The results of field studies carried out on different plant species (winter rye and wheat, spring barley, oats, Scots pine, wild vetch, crested hairgrass) in various radioecological situations (nuclear weapon testing, the Chernobyl accident, uranium and radium processing) to investigate the effects of long-term chronic exposure to radionuclides are discussed. Plant populations growing in areas with relatively low levels of pollution are characterized by an increased level of both cytogenetic disturbances and genetic diversity. Although ionizing radiation causes primary damage at the molecular level, there are emergent effects at the level of populations, non-predictable from the knowledge of elementary mechanisms of cellular effects formation. Accumulation of cellular alterations may afterward influence biological parameters important for populations such as health and reproduction. Presented data provide evidence that in plant populations inhabiting heavily contaminated territories cytogenetic damage could be accompanied by a decrease in reproductive capacity. However, in less contaminated sites, because of the scarcity of data available, a steady relationship between cytogenetic effects and reproductive capacity was not revealed. Under radioactive contamination of the plant's environment, a population's resistance to exposure may increase. However, there are radioecological situations where an enhanced radioresistance has not evolved or has not persisted

  16. Disjunct populations of European vascular plant species keep the same climatic niches

    DEFF Research Database (Denmark)

    Wasof, Safaa; Lenoir, Jonathan; Aarrestad, Per Arild

    2015-01-01

    separated for thousands of years. Location: European Alps and Fennoscandia. Methods: Of the studied pool of 888 terrestrial vascular plant species occurring in both the Alps and Fennoscandia, we used two complementary approaches to test and quantify climatic-niche shifts for 31 species having strictly......Aim: Previous research on how climatic niches vary across species ranges has focused on a limited number of species, mostly invasive, and has not, to date, been very conclusive. Here we assess the degree of niche conservatism between distant populations of native alpine plant species that have been...... to be largely valid for arctic-alpine plants....

  17. Model calculations of the influence of population distribution on the siting of nuclear power plants

    International Nuclear Information System (INIS)

    Nielsen, F.; Walmod-Larsen, O.

    1984-02-01

    This report was prepared for a working group established in April 1981 by the Danish Environmental Protection Agency with the task of investigating siting problems of nuclear power stations in Denmark. The purpose of the working group was to study the influence of the population density around a site on nuclear power safety. The importance of emergency planning should be studied as well. In this model study two specific accident sequences were simulated on a 1000 MWe nuclear power plant. The plant was assumed to be placed in the center of two different model population distributions. The concequences for the two population distributions from the two accidents were calculated for the most frequent weather conditions. Doses to individuals were calculated for the bone marrow, lungs, gastrointestinal tract, thyroidea and for the whole body. The collective whole body doses were also calculated for the two populations considered. (author)

  18. Contrasting trait responses in plant communities to experimental and geographic variation in precipitation

    DEFF Research Database (Denmark)

    Sandel, Brody Steven; Goldstein, Leah; Kraft, Nathan

    2010-01-01

    Patterns of precipitation are likely to change significantly in the coming century, with important but poorly understood consequences for plant communities. Experimental and correlative studies may provide insight into expected changes, but little research has addressed the degree of concordance...... between these approaches. We synthesized results from four experimental water addition studies with a correlative analysis of community changes across a large natural precipitation gradient in the United States. We investigated whether community composition, summarized with plant functional traits......, responded similarly to increasing precipitation among studies and sites. In field experiments, increased precipitation favored species with small seed size,short leaf life span and high leaf nitrogen (N) concentration. However, with increasing precipitation along the natural gradient, community composition...

  19. Low doses of six toxicants change plant size distribution in dense populations of Lactuca sativa.

    Science.gov (United States)

    Belz, Regina G; Patama, Marjo; Sinkkonen, Aki

    2018-08-01

    Toxicants are known to have negligible or stimulatory, i.e. hormetic, effects at low doses below those that decrease the mean response of a plant population. Our earlier observations indicated that at such low toxicant doses the growth of very fast- and slow-growing seedlings is selectively altered, even if the population mean remains constant. Currently, it is not known how common these selective low-dose effects are, whether they are similar among fast- and slow-growing seedlings, and whether they occur concurrently with hormetic effects. We tested the response of Lactuca sativa in complete dose-response experiments to six different toxicants at doses that did not decrease population mean and beyond. The tested toxicants were IAA, parthenin, HHCB, 4-tert-octylphenol, glyphosate, and pelargonic acid. Each experiment consisted of 14,400-16,800 seedlings, 12-14 concentrations, 24 replicates per concentration and 50 germinated seeds per replicate. We analyzed the commonness of selective low-dose effects and explored if toxic effects and hormetic stimulation among fast- and slow-growing individuals occurred at the same concentrations as they occur at the population level. Irrespective of the observed response pattern and toxicant, selective low-dose effects were found. Toxin effects among fast-growing individuals usually started at higher doses compared to the population mean, while the opposite was found among slow-growing individuals. Very low toxin exposures tended to homogenize plant populations due to selective effects, while higher, but still hormetic doses tended to heterogenize plant populations. Although the extent of observed size segregation varied with the specific toxin tested, we conclude that a dose-dependent alteration in size distribution of a plant population may generally apply for many toxin exposures. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Experimental investigations on the transient behaviour of nuclear heat plants with natural convection

    International Nuclear Information System (INIS)

    Adam, E.; Sydow, J.; Wolff, J.

    1988-01-01

    Apart from the theoretical approach, practical experiments concerning the transient behaviour of the primary loop of reactors with natural coolant convection are necessary in order to evaluate the safety systems of reactors providing heat for industrial and communal consumers. The article presents experiments concerning the transient behaviour of the experimental plant DANTON, which models the reactor AST-500, and gives a preview of further research. (orig.) [de

  1. The UO2 pellets plant experimental background of the established process

    International Nuclear Information System (INIS)

    Aparicio Arroyo, E.; Alonso Folgueras, J. A.

    1969-01-01

    An account of the UO 2 research and development carried out at the JEN is first given. This includes a 10 tons/year pellet Plant construction. Experimental background of the process is established, pointing out both milling advantages and risks, granulation devices, automatic press selection, binder removing and sintering furnaces. Origin, surface area, grain size and 0/U rate are considered as raw material reception parameters, although this process shows a wide scope. (Author) 13 refs

  2. Validation of the CATHARE2 code against experimental data from Brayton-cycle plants

    International Nuclear Information System (INIS)

    Bentivoglio, Fabrice; Tauveron, Nicolas; Geffraye, Genevieve; Gentner, Herve

    2008-01-01

    In recent years the Commissariat a l'Energie Atomique (CEA) has commissioned a wide range of feasibility studies of future-advanced nuclear reactors, in particular gas-cooled reactors (GCR). The thermohydraulic behaviour of these systems is a key issue for, among other things, the design of the core, the assessment of thermal stresses, and the design of decay heat removal systems. These studies therefore require efficient and reliable simulation tools capable of modelling the whole reactor, including the core, the core vessel, piping, heat exchangers and turbo-machinery. CATHARE2 is a thermal-hydraulic 1D reference safety code developed and extensively validated for the French pressurized water reactors. It has been recently adapted to deal also with gas-cooled reactor applications. In order to validate CATHARE2 for these new applications, CEA has initiated an ambitious long-term experimental program. The foreseen experimental facilities range from small-scale loops for physical correlations, to component technology and system demonstration loops. In the short-term perspective, CATHARE2 is being validated against existing experimental data. And in particular from the German power plants Oberhausen I and II. These facilities have both been operated by the German utility Energie Versorgung Oberhausen (E.V.O.) and their power conversion systems resemble to the high-temperature reactor concepts: Oberhausen I is a 13.75-MWe Brayton-cycle air turbine plant, and Oberhausen II is a 50-MWe Brayton-cycle helium turbine plant. The paper presents these two plants, the adopted CATHARE2 modelling and a comparison between experimental data and code results for both steady state and transient cases

  3. Computer techniques for experimental work in GDR nuclear power plants with WWER

    International Nuclear Information System (INIS)

    Stemmler, G.

    1985-01-01

    Nuclear power plant units with WWER are being increasingly equipped with high-performance, programmable process control computers. There are, however, essential reasons for further advancing the development of computer-aided measuring systems, in particular for experimental work. A special structure of such systems, which is based on the division into relatively rigid data registration and primary handling and into further processing by advanced programming language, has proved useful in the GDR. (author)

  4. Changes in plant availability of Pu-238 during a nine year experimental period

    International Nuclear Information System (INIS)

    Eriksson, Aa.

    1985-01-01

    A short description is given of the changes observed in the plant availability of Pu-238 in eight soils during a nine year experimental period. It was found that during the first four-year period with clover as test crop, the plant uptake of Pu-238 was reduced with availability half lives ranging from 0.8 to 2.0 years. The reduction rate seemed proportional to the initial uptake levels, except for lime rich clay soils, where the reduction rate was high regardless of the uptake level. In 1980 when the test crop clover was replaced by spring wheat, the necessary soil management operations caused intenser aeration and drying in one block of the replicates. As a consequence, the Pu-uptake in that block became considerably higher than in the others. This event can be interpreted as an indirect evidence for the reversibility of that process in soil, which has caused the reduced plant availability of Pu-238

  5. EXPERIMENTAL RESEARCH OF THE INFLUENCE OF VARIOUS TYPES OF SOLAR COLLECTORS FOR PERFORMANCE SOLAR DESALINATION PLANT

    Directory of Open Access Journals (Sweden)

    Rakhmatulin I.R.

    2014-04-01

    Full Text Available The article discusses the possibility of using renewable energy for water purification. Results of analysis of a preferred energy source for a water purification using installed in places where fresh water shortages and a lack of electrical energy. The possibility of desalination of salt water using solar energy for regions with temperate climate. Presented desalination plant working on energy vacuum solar collectors, principles of action developed by the desalination plant. The experimental results of a constructed distiller when working with vacuum glass tubes and vacuum tubes with copper core inside. Conclusions about the possibility of using solar collectors for water desalination, are tips and tricks to improve the performance of solar desalination plant.

  6. Uncoupling the effects of seed predation and seed dispersal by granivorous ants on plant population dynamics.

    Directory of Open Access Journals (Sweden)

    Xavier Arnan

    Full Text Available Secondary seed dispersal is an important plant-animal interaction, which is central to understanding plant population and community dynamics. Very little information is still available on the effects of dispersal on plant demography and, particularly, for ant-seed dispersal interactions. As many other interactions, seed dispersal by animals involves costs (seed predation and benefits (seed dispersal, the balance of which determines the outcome of the interaction. Separate quantification of each of them is essential in order to understand the effects of this interaction. To address this issue, we have successfully separated and analyzed the costs and benefits of seed dispersal by seed-harvesting ants on the plant population dynamics of three shrub species with different traits. To that aim a stochastic, spatially-explicit individually-based simulation model has been implemented based on actual data sets. The results from our simulation model agree with theoretical models of plant response dependent on seed dispersal, for one plant species, and ant-mediated seed predation, for another one. In these cases, model predictions were close to the observed values at field. Nonetheless, these ecological processes did not affect in anyway a third species, for which the model predictions were far from the observed values. This indicates that the balance between costs and benefits associated to secondary seed dispersal is clearly related to specific traits. This study is one of the first works that analyze tradeoffs of secondary seed dispersal on plant population dynamics, by disentangling the effects of related costs and benefits. We suggest analyzing the effects of interactions on population dynamics as opposed to merely analyzing the partners and their interaction strength.

  7. Perceptions of Medicinal Plant Use Amongst the Hispanic Population in the St. Louis Metropolitan Area

    Directory of Open Access Journals (Sweden)

    Kim M. Grafford

    2016-10-01

    Full Text Available Introduction: Medicinal plant use in the United States has increased as reported by the National Center of Complementary and Integrative Health and U.S. Census Bureau.However, little is known about how many minority groups in the United States use medicinal plants.There is a rise in the Hispanic population; a community with a steep tradition of medicinal plant use, in the U.S., so understanding the perceptions of medicinal plant use is useful to healthcare providers. Methods: A survey was designed to gauge a better understanding of the perceptions of medicinal plant use amongst Latino patients with varying education levels who reside in the St. Louis Metropolitan Area. Survey questions highlighted the perceptions of medicinal plants use, patient communication regarding medicinal plant use with healthcare providers (pharmacists and doctors, and the impact the education level has on medicinal plant use. Results: Surveys were distributed to six different investigational sites around the St. Louis Metropolitan Area from August 2015 to December 2015. Survey respondents identified 45 different plants/herbs that they currently use or had used at some point in their life. Those with higher levels of education had varying opinions on medicinal plant use with their current practices. Conclusion: The participants’ high interest in the use of medicinal plants exemplifies the need for enhanced communication between patients and healthcare professionals about medicinal plant use. However, it was hard to determine whether the participants’ level of education had any direct relationship to this use. Conflict of Interest None   Type: Original Research

  8. Sex enhances adaptation by unlinking beneficial from detrimental mutations in experimental yeast populations

    Directory of Open Access Journals (Sweden)

    Gray Jeremy C

    2012-03-01

    Full Text Available Abstract Background The maintenance of sexuality is a classic problem in evolutionary biology because it is a less efficient mode of reproduction compared with asexuality; however, many organisms are sexual. Theoretical work suggests sex facilitates natural selection, and experimental data support this. However, there are fewer experimental studies that have attempted to determine the mechanisms underlying the advantage of sex. Two main classes of hypotheses have been proposed to explain its advantage: detrimental mutation clearance and beneficial mutation accumulation. Here we attempt to experimentally differentiate between these two classes by evolving Saccharomyces cerevisiae populations that differ only in their ability to undergo sex, and also manipulate mutation rate. We cannot manipulate the types of mutation that occur, but instead propagate populations in both stressful and permissive environments and assume that the extent of detrimental mutation clearance and beneficial mutation incorporation differs between them. Results After 300 mitotic generations interspersed with 11 rounds of sex we found there was no change or difference in fitness between sexuals and asexuals propagated in the permissive environment, regardless of mutation rate. Sex conferred a greater extent of adaptation in the stressful environment, and wild-type and elevated mutation rate sexual populations adapted equivalently. However, the asexual populations with an elevated mutation rate appeared more retarded in their extent of adaptation compared to asexual wild-type populations. Conclusions Sex provided no advantage in the permissive environment where beneficial mutations were rare. We could not evaluate if sex functioned to clear detrimental mutations more effectively or not here as no additional fitness load was observed in the mutator populations. However, in the stressful environment, where detrimental mutations were likely of more consequence, and where

  9. Plant growth response in experimental soilless mixes prepared from coal combustion products and organic waste materials

    Energy Technology Data Exchange (ETDEWEB)

    Bardhan, S.; Watson, M.; Dick, W.A. [Ohio State University, Wooster, OH (United States)

    2008-07-15

    Large quantities of organic materials such as animal manures, yard trimmings, and biosolids are produced each year. Beneficial use options for them are often limited, and composting has been proposed as a way to better manage these organic materials. Similarly, burning of coal created 125 million tons of coal combustion products (CCP) in the United States in 2006. An estimated 53 million tons of CCP were reused, whereas the remainder was deposited in landfills. By combining CCP and composted organic materials (COM), we were able to create soilless plant growth mixes with physicochemical conditions that can support excellent plant growth. An additional benefit is the conservation of natural raw materials, such as peat, which is generally used for making soilless mixes. Experimental mixes were formulated by combining CCP and COM at ratios ranging from 2:8 to 8:2 (vol/vol), respectively. Water content at saturation for the created mixes was 63% to 72%, whereas for the commercial control, it was 77%. pH values for the best performing mixes ranged between 5.9 and 6.8. Electrical conductivity and concentrations of required plant nutrient were also within plant growth recommendations for container media. Significantly (P < 0.0001) higher plant biomass growth (7%-130%) was observed in the experimental mixes compared with a commercial mix. No additional fertilizers were provided during the experiment, and reduced fertilization costs can thus accrue as an added benefit to the grower. In summary, combining CCP and COM, derived from source materials often viewed as wastes, can create highly productive plant growth mixes.

  10. Population genetics and the evolution of geographic range limits in an annual plant.

    Science.gov (United States)

    Moeller, David A; Geber, Monica A; Tiffin, Peter

    2011-10-01

    Abstract Theoretical models of species' geographic range limits have identified both demographic and evolutionary mechanisms that prevent range expansion. Stable range limits have been paradoxical for evolutionary biologists because they represent locations where populations chronically fail to respond to selection. Distinguishing among the proposed causes of species' range limits requires insight into both current and historical population dynamics. The tools of molecular population genetics provide a window into the stability of range limits, historical demography, and rates of gene flow. Here we evaluate alternative range limit models using a multilocus data set based on DNA sequences and microsatellites along with field demographic data from the annual plant Clarkia xantiana ssp. xantiana. Our data suggest that central and peripheral populations have very large historical and current effective population sizes and that there is little evidence for population size changes or bottlenecks associated with colonization in peripheral populations. Whereas range limit populations appear to have been stable, central populations exhibit a signature of population expansion and have contributed asymmetrically to the genetic diversity of peripheral populations via migration. Overall, our results discount strictly demographic models of range limits and more strongly support evolutionary genetic models of range limits, where adaptation is prevented by a lack of genetic variation or maladaptive gene flow.

  11. Evaluation Of The Exclusion And Low Population Areas Around A Nuclear Power Plant

    International Nuclear Information System (INIS)

    Tawfik, F.S.

    2011-01-01

    Being adjacent to the nuclear power plant (NPP) the exclusion area (EA) is the area of greatest importance. It essentially defines a buffer zone where the public has no access. It helps to define the fenced plant area, the site area and the public area. Also, the low population area is the area immediately surrounding the exclusion area near a licensed reactor in terms of public safety and the ability of residents to get away from the plant in an emergency. This study clarifies their significance and reviews the international approach on them. Assuming the nuclear power plant site at the north coast of Egypt, the exclusion area and low population area are determined according to CFR (2002). In this method, a maximum possible amount of radioactivity release (called a source term) should be assumed. The boiling water reactor (BWR) with a power 1000 MW was used to carry the calculation and assuming a severe loss of coolant accident with meltdown of reactor. The site specific data have been collected, investigated and processed. The effect of the degree of atmospheric stability and building width of the plant were examined. The proceeding factors that control the determination of exclusion area and low population area should be taken into consideration in the site evaluation stage and design basis of NPP to set a minimum distances for them

  12. Effect Of Plant Population On Yield Of Maize And Climbing Beans ...

    African Journals Online (AJOL)

    A field experiment was conducted at Kachwekano near Kabale town for two seasons: second rains of 1996 (1996b) and first rains of 1997 (1997a), to determine the appropriate plant population density (PPD) of maize that would maximize bean yield in an intercrop system. The treatments were: (a) maize PPD ranging from ...

  13. Past climate-driven range shifts and population genetic diversity in arctic plants

    DEFF Research Database (Denmark)

    Pellissier, Loïc; Eidesen, Pernille Bronken; Ehrich, Dorothee

    2016-01-01

    High intra-specific genetic diversity is necessary for species adaptation to novel environments under climate change, but species tracking suitable conditions are losing alleles through successive founder events during range shift. Here, we investigated the relationship between range shift since ...... the Last Glacial Maximum (LGM) and extant population genetic diversity across multiple plant species to understand variability in species responses...

  14. Transients drive the demographic dynamics of plant populations in variable environments

    DEFF Research Database (Denmark)

    McDonald, Jenni L; Stott, Iain; Townley, Stuart

    2016-01-01

    clear patterns related to growth form. We find a surprising tendency for plant populations to boom rather than bust in response to temporal changes in vital rates and that stochastic growth rates increase with increasing tendency to boom. Synthesis. Transient dynamics contribute significantly...

  15. Yield, yield components and dry matter digestibility of alfalfa experimental populations

    Directory of Open Access Journals (Sweden)

    Katić Slobodan

    2010-01-01

    Full Text Available Alfalfa is the most important forage crop grown in the temperate regions. It is cultivated for production of vegetative aerial mass used fresh or as hay, and recently as haylage and silage. In many centres worldwide, efforts are made to breed and create new alfalfa cultivars with both higher yields and of higher nutritional value. The aim of this paper was to determine yield and digestibility of 12 experimental populations of alfalfa, and to compare their results to the yields of well-known domestic alfalfa commercial cultivars. The results show significant differences in yield of green forage and dry matter among alfalfa populations, as well as in yield components, height, proportion of leaves in yield and growth rate (tab. 1, 2 and 3. Differences between in vitro digestible dry matter (% and yields of in vitro digestible dry matter (t ha-1 were also significant (tab. 5 and 6. Yield and quality of experimental populations were at the same level or higher than of control cultivars. Synthetic SINUSA exceeded the control cutivars (NS Mediana ZMS V and Banat VS in yield and quality of dry matter. .

  16. Experimental warming decreases arbuscular mycorrhizal fungal colonization in prairie plants along a Mediterranean climate gradient

    Directory of Open Access Journals (Sweden)

    Hannah Wilson

    2016-06-01

    Full Text Available Background: Arbuscular mycorrhizal fungi (AMF provide numerous services to their plant symbionts. Understanding climate change effects on AMF, and the resulting plant responses, is crucial for predicting ecosystem responses at regional and global scales. We investigated how the effects of climate change on AMF-plant symbioses are mediated by soil water availability, soil nutrient availability, and vegetation dynamics. Methods: We used a combination of a greenhouse experiment and a manipulative climate change experiment embedded within a Mediterranean climate gradient in the Pacific Northwest, USA to examine this question. Structural equation modeling (SEM was used to determine the direct and indirect effects of experimental warming on AMF colonization. Results: Warming directly decreased AMF colonization across plant species and across the climate gradient of the study region. Other positive and negative indirect effects of warming, mediated by soil water availability, soil nutrient availability, and vegetation dynamics, canceled each other out. Discussion: A warming-induced decrease in AMF colonization would likely have substantial consequences for plant communities and ecosystem function. Moreover, predicted increases in more intense droughts and heavier rains for this region could shift the balance among indirect causal pathways, and either exacerbate or mitigate the negative, direct effect of increased temperature on AMF colonization.

  17. Forecasting climate change impacts on plant populations over large spatial extents

    Science.gov (United States)

    Tredennick, Andrew T.; Hooten, Mevin B.; Aldridge, Cameron L.; Homer, Collin G.; Kleinhesselink, Andrew R.; Adler, Peter B.

    2016-01-01

    Plant population models are powerful tools for predicting climate change impacts in one location, but are difficult to apply at landscape scales. We overcome this limitation by taking advantage of two recent advances: remotely sensed, species-specific estimates of plant cover and statistical models developed for spatiotemporal dynamics of animal populations. Using computationally efficient model reparameterizations, we fit a spatiotemporal population model to a 28-year time series of sagebrush (Artemisia spp.) percent cover over a 2.5 × 5 km landscape in southwestern Wyoming while formally accounting for spatial autocorrelation. We include interannual variation in precipitation and temperature as covariates in the model to investigate how climate affects the cover of sagebrush. We then use the model to forecast the future abundance of sagebrush at the landscape scale under projected climate change, generating spatially explicit estimates of sagebrush population trajectories that have, until now, been impossible to produce at this scale. Our broadscale and long-term predictions are rooted in small-scale and short-term population dynamics and provide an alternative to predictions offered by species distribution models that do not include population dynamics. Our approach, which combines several existing techniques in a novel way, demonstrates the use of remote sensing data to model population responses to environmental change that play out at spatial scales far greater than the traditional field study plot.

  18. Boom or bust? A comparative analysis of transient population dynamics in plants

    DEFF Research Database (Denmark)

    Stott, Iain; Franco, Miguel; Carslake, David

    2010-01-01

    researchers as further possible effectors of complicated dynamics. Previously published methods of transient analysis have tended to require knowledge of initial population structure. However, this has been overcome by the recent development of the parametric Kreiss bound (which describes how large...... a population must become before reaching its maximum possible transient amplification following a disturbance) and the extension of this and other transient indices to simultaneously describe both amplified and attenuated transient dynamics. We apply the Kreiss bound and other transient indices to a data base...... worrying artefact of basic model parameterization. Synthesis. Transient indices describe how big or how small plant populations can get, en route to long-term stable rates of increase or decline. The patterns we found in the potential for transient dynamics, across many species of plants, suggest...

  19. Dynamic model with experimental validation of a biogas-fed SOFC plant

    International Nuclear Information System (INIS)

    D'Andrea, G.; Gandiglio, M.; Lanzini, A.; Santarelli, M.

    2017-01-01

    Highlights: • 60% of DIR into the SOFC anode reduces the air blower parasitic losses by 14%. • PID-controlled cathode airflow enables fast thermal regulation of the SOFC. • Stack overheating occurs due to unexpected reductions in the cathode airflow. • Current ramp rates higher than +0.30 A/min lead to an excessive stack overheating. - Abstract: The dynamic model of a poly-generation system based on a biogas-fed solid oxide fuel cell (SOFC) plant is presented in this paper. The poly-generation plant was developed in the framework of the FP7 EU-funded project SOFCOM ( (www.sofcom.eu)), which consists of a fuel-cell based polygeneration plant with CO_2 capture and re-use. CO_2 is recovered from the anode exhaust of the SOFC (after oxy-combustion, cooling and water condensation) and the Carbon is fixed in the form of micro-algae in a tubular photobioreactor. This work focuses on the dynamic operation of the SOFC module running on steam-reformed biogas. Both steady state and dynamic operation of the fuel cell stack and the related Balance-of-Plant (BoP) has been modeled in order to simulate the thermal behavior and performance of the system. The model was validated against experimental data gathered during the operation of the SOFCOM proof-of-concept showing good agreement with the experimental data. The validated model has been used to investigate further on the harsh off-design operation of the proof-of-concept. Simulation results provide guidelines for an improved design of the control system of the plant, highlighting the feasible operating region under safe conditions and means to maximize the overall system efficiency.

  20. Assessment of Genetic Heterogeneity in Structured Plant Populations Using Multivariate Whole-Genome Regression Models.

    Science.gov (United States)

    Lehermeier, Christina; Schön, Chris-Carolin; de Los Campos, Gustavo

    2015-09-01

    Plant breeding populations exhibit varying levels of structure and admixture; these features are likely to induce heterogeneity of marker effects across subpopulations. Traditionally, structure has been dealt with as a potential confounder, and various methods exist to "correct" for population stratification. However, these methods induce a mean correction that does not account for heterogeneity of marker effects. The animal breeding literature offers a few recent studies that consider modeling genetic heterogeneity in multibreed data, using multivariate models. However, these methods have received little attention in plant breeding where population structure can have different forms. In this article we address the problem of analyzing data from heterogeneous plant breeding populations, using three approaches: (a) a model that ignores population structure [A-genome-based best linear unbiased prediction (A-GBLUP)], (b) a stratified (i.e., within-group) analysis (W-GBLUP), and (c) a multivariate approach that uses multigroup data and accounts for heterogeneity (MG-GBLUP). The performance of the three models was assessed on three different data sets: a diversity panel of rice (Oryza sativa), a maize (Zea mays L.) half-sib panel, and a wheat (Triticum aestivum L.) data set that originated from plant breeding programs. The estimated genomic correlations between subpopulations varied from null to moderate, depending on the genetic distance between subpopulations and traits. Our assessment of prediction accuracy features cases where ignoring population structure leads to a parsimonious more powerful model as well as others where the multivariate and stratified approaches have higher predictive power. In general, the multivariate approach appeared slightly more robust than either the A- or the W-GBLUP. Copyright © 2015 by the Genetics Society of America.

  1. Replaying Evolution to Test the Cause of Extinction of One Ecotype in an Experimentally Evolved Population.

    Directory of Open Access Journals (Sweden)

    Caroline B Turner

    Full Text Available In a long-term evolution experiment with Escherichia coli, bacteria in one of twelve populations evolved the ability to consume citrate, a previously unexploited resource in a glucose-limited medium. This innovation led to the frequency-dependent coexistence of citrate-consuming (Cit+ and non-consuming (Cit- ecotypes, with Cit-bacteria persisting on the exogenously supplied glucose as well as other carbon molecules released by the Cit+ bacteria. After more than 10,000 generations of coexistence, however, the Cit-lineage went extinct; cells with the Cit-phenotype dropped to levels below detection, and the Cit-clade could not be detected by molecular assays based on its unique genotype. We hypothesized that this extinction was a deterministic outcome of evolutionary change within the population, specifically the appearance of a more-fit Cit+ ecotype that competitively excluded the Cit-ecotype. We tested this hypothesis by re-evolving the population from a frozen population sample taken within 500 generations of the extinction and from another sample taken several thousand generations earlier, in each case for 500 generations and with 20-fold replication. To our surprise, the Cit-type did not go extinct in any of these replays, and Cit-cells also persisted in a single replicate that was propagated for 2,500 generations. Even more unexpectedly, we showed that the Cit-ecotype could reinvade the Cit+ population after its extinction. Taken together, these results indicate that the extinction of the Cit-ecotype was not a deterministic outcome driven by competitive exclusion by the Cit+ ecotype. The extinction also cannot be explained by demographic stochasticity alone, as the population size of the Cit-ecotype should have been many thousands of cells even during the daily transfer events. Instead, we infer that the extinction must have been caused by a rare chance event in which some aspect of the experimental conditions was inadvertently perturbed.

  2. Population level analysis of evolved mutations underlying improvements in plant hemicellulose and cellulose fermentation by Clostridium phytofermentans.

    Directory of Open Access Journals (Sweden)

    Supratim Mukherjee

    Full Text Available The complexity of plant cell walls creates many challenges for microbial decomposition. Clostridium phytofermentans, an anaerobic bacterium isolated from forest soil, directly breaks down and utilizes many plant cell wall carbohydrates. The objective of this research is to understand constraints on rates of plant decomposition by Clostridium phytofermentans and identify molecular mechanisms that may overcome these limitations.Experimental evolution via repeated serial transfers during exponential growth was used to select for C. phytofermentans genotypes that grow more rapidly on cellobiose, cellulose and xylan. To identify the underlying mutations an average of 13,600,000 paired-end reads were generated per population resulting in ∼300 fold coverage of each site in the genome. Mutations with allele frequencies of 5% or greater could be identified with statistical confidence. Many mutations are in carbohydrate-related genes including the promoter regions of glycoside hydrolases and amino acid substitutions in ABC transport proteins involved in carbohydrate uptake, signal transduction sensors that detect specific carbohydrates, proteins that affect the export of extracellular enzymes, and regulators of unknown specificity. Structural modeling of the ABC transporter complex proteins suggests that mutations in these genes may alter the recognition of carbohydrates by substrate-binding proteins and communication between the intercellular face of the transmembrane and the ATPase binding proteins.Experimental evolution was effective in identifying molecular constraints on the rate of hemicellulose and cellulose fermentation and selected for putative gain of function mutations that do not typically appear in traditional molecular genetic screens. The results reveal new strategies for evolving and engineering microorganisms for faster growth on plant carbohydrates.

  3. Plant growth promoting rhizobacteria reduce aphid population and enhance the productivity of bread wheat.

    Science.gov (United States)

    Naeem, Muhammad; Aslam, Zubair; Khaliq, Abdul; Ahmed, Jam Nazir; Nawaz, Ahmad; Hussain, Mubshar

    2018-04-24

    Plant growth promoting rhizobacteria increase plant growth and give protection against insect pests and pathogens. Due to the negative impact of chemical pesticides on environment, alternatives to these chemicals are needed. In this scenario, the biological methods of pest control offer an eco-friendly and an attractive option. In this study, the effect of two plant growth promoting rhizobacterial strains (Bacillus sp. strain 6 and Pseudomonas sp. strain 6K) on aphid population and wheat productivity was evaluated in an aphid susceptible (Pasban-90) and resistant (Inqlab-91) wheat cultivar. The seeds were inoculated with each PGPR strain, separately or the combination of both. The lowest aphid population (2.1tiller -1 ), and highest plant height (85.8cm), number of spikelets per spike (18), grains per spike (44), productive tillers (320m -2 ), straw yield (8.6Mgha -1 ), and grain yield (4.8Mgha -1 ) were achieved when seeds were inoculated with Bacillus sp. strain 6+Pseudomonas sp. strain 6K. The grain yield of both varieties was enhanced by 35.5-38.9% with seed inoculation with both bacterial strains. Thus, the combine use of both PGPR strains viz. Bacillus sp. strain 6+Pseudomonas sp. strain 6K offers an attractive option to reduce aphid population tied with better wheat productivity. Copyright © 2018 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  4. Plant quality and conspecific density effects on Anaphothrips obscurus (Thysanoptera: Thripidae) wing diphenism and population ecology.

    Science.gov (United States)

    Reisig, Dominic D; Godfrey, Larry D; Marcum, Daniel B

    2010-04-01

    Factors that influence thysanopteran wing diphenism are not well known. In these studies, the impact of food quality, mediated through nitrogen addition, and conspecific density was explored on the wing diphenism of an herbivorous thrips species (Anaphothrips obscurus Müller) (Thysanoptera: Thripidae). In the first study, nitrogen was added to timothy grass (Phleum pretense L.) (Poales: Poaceae) transplants, and naturally occurring thrips populations were caged on the plants. Thrips abundance and foliar nutrients were assessed every 2 wk. A separate factorial experiment in growth chambers explored the impact of both plant nitrogen addition and thrips abundance on wing diphenism. Thrips density was manipulated by adding either 3 or 40 thrips to potted and caged timothy. Thrips abundance and foliar nutrients were measured 58 d after treatment placement. Plant quality directly affected thrips wing diphenism independent of thrips density in both experiments. Near the end of the field cage experiment, density may have indirectly impacted wing diphenism. In both experiments, plant quality and thrips density interacted to affect thrips population abundance. Plant quality alone can affect thrips wing diphenism, but it remains unclear whether density alone can affect thrips wing diphenism. This is a unique and understudied system that will be useful to examine generalized theories on the negative interaction between reproduction and dispersal.

  5. Gamma-radiation effect on the parameters of the population recovery of plants

    Directory of Open Access Journals (Sweden)

    N.I. Ivanishvili

    2016-12-01

    Full Text Available Investigation of the effects of different physic-chemical factors on the ecosystems is one of the important scientific tasks. From this perspective, it is to be mentioned an effect of such a strong damaging factor as ionizing radiation. Radiation damage is reflected differently in relation to the levels of organization of living organisms. On the relatively early stage of radiation damage determination of post-irradiation regeneration indicators on population level gives possibility to forecast the sustainability of ecosystems. In order to determine the indicators of post-irradiation regeneration of plant populations we have used as a model water plant – Lemna minor L. During the exposure of radiation on different levels of organization differences are identified not only according to qualitative features but also by the character of direction of the development of the processes of postradiation regeneration. A conclusion is made that if during the acute radiation it is possible to determine radioresistance of certain plants, which is based on the plant potential to post-radiation regeneration, the investigation carried out through chronic irradiation gives the possibility to determine the indicators of the ability of the plant to adapt to the radiation.

  6. Fissile material holdup monitoring in the PREPP [Process Experimental Pilot Plant] process

    International Nuclear Information System (INIS)

    Becker, G.K.; Pawelko, R.J.

    1989-01-01

    The Process Experimental Pilot Plant (PREPP) is an incineration system designed to thermally process mixed transuranic (TRU) waste and TRU contaminated low-level waste. The TRU isotopic composition is that of weapons grade plutonium (Pu) which necessitates that criticality prevention measures by incorporated into the plant design and operation. Criticality safety in the PREPP process is assured through the utilization of mass and moderation control in conjunction with favorable vessel geometries. The subject of this paper concerns the Pu mass holdup instrumentation system which is an integral part of the inprocess mass control strategy. Plant vessels and components requiring real-time mass holdup measurements were selected based on their evaluated potential for achieving physically credible Pu mass loadings and associated parameters which could lead to a criticality event. If the parameters requisite to a criticality occurrence could not physically be achieved under credible plant conditions, the particular location only required periodic portable holdup monitoring. Based on these analyses five real-time holdup monitoring locations were identified for criticality assurance purposes. An additional real-time instrument is part of the system but serves primarily in the capacity of providing operational support data. 1 fig

  7. An experimental study of the 14C transfer from air to rice plant by photosynthesis

    International Nuclear Information System (INIS)

    Jun, In; Kang, Heeseok; Keum, Dongkweon; Choi, Yongho; Lee, Hansoo; Lee, Changwoo

    2007-01-01

    Experimental studies were performed under controlled environmental conditions to observe the deposition and subsequent allocation of 14 C following a short-term fumigation of a major Korean crop with 14 CO 2 . The fumigation of the rice plants was performed at five different times during their growth in a transparent box and the fumigation time was 40 minutes. The 14 C in the fumigation box was collected into collection vials every 5 minutes using an air sampler. A duplicate plant sampling was made immediately after the end of fumigation and another is going to be made at the normal harvest time. After the 2nd and 3rd fumigation experiments, plant sampling was made 3 times more till harvest. The samples will be ground into powder after removing the moisture completely and the trapped 14 C in the carbosorb vials by sample oxidizer will be analyzed by Liquid Scintillation Counter. This paper only shows the analysis results of air samples because no plant sample was analyzed yet. (author)

  8. Managing Natural and Reintroduced Rare Plant Populations within a Large Government Reservation

    Energy Technology Data Exchange (ETDEWEB)

    Carlsen, T M; Paterson, L E; Alfaro, T M

    2009-07-15

    California is home to many large government reservations that have been in existence for decades. Many of these reservations were formed to support various Department of Defense and Department of Energy national defense activities. Often, only a very small percentage of the reservation is actively used for programmatic activities, resulting in large areas of intact habitat. In some cases, this has benefited rare plant populations, as surrounding lands have been developed for residential or industrial use. However, land management activities such as the suppression or active use of fire and other disturbance (such as fire trail grading) can also work to either the detriment or benefit of rare plant populations at these sites. A management regime that is beneficial to the rare plant populations of interest and is at best consistent with existing site programmatic activities, and at a minimum does not impact such activities, has the best potential for a positive outcome. As a result, some species may be 'difficult' while others may be 'easy' to manage in this context, depending on how closely the species biological requirements match the programmatic activities on the reservation. To illustrate, we compare and contrast two rare annual plant species found at Lawrence Livermore National Laboratory's Site 300. Although several populations of Amsinckia grandiflora have been restored on the site, and all populations are intensively managed, this species continues to decline. In contrast, Blepharizonia plumosa appears to take advantage of the annual controlled burns conducted on the site, and is thriving.

  9. Effects of Plant Extracts on Microbial Population, Methane Emission and Ruminal Fermentation Characteristics in

    Directory of Open Access Journals (Sweden)

    E. T. Kim

    2012-06-01

    Full Text Available This study was conducted to evaluate effects of plant extracts on methanogenesis and rumen microbial diversity in in vitro. Plant extracts (Artemisia princeps var. Orientalis; Wormwood, Allium sativum for. Pekinense; Garlic, Allium cepa; Onion, Zingiber officinale; Ginger, Citrus unshiu; Mandarin orange, Lonicera japonica; Honeysuckle were obtained from the Plant Extract Bank at Korea Research Institute of Bioscience and Biotechnology. The rumen fluid was collected before morning feeding from a fistulated Holstein cow fed timothy and commercial concentrate (TDN; 73.5%, crude protein; 19%, crude fat; 3%, crude fiber; 12%, crude ash; 10%, Ca; 0.8%, P; 1.2% in the ratio of 3 to 2. The 30 ml of mixture, comprising McDougall buffer and rumen liquor in the ratio of 4 to 1, was dispensed anaerobically into serum bottles containing 0.3 g of timothy substrate and plant extracts (1% of total volume, respectively filled with O2-free N2 gas and capped with a rubber stopper. The serum bottles were held in a shaking incubator at 39°C for 24 h. Total gas production in all plant extracts was higher (p<0.05 than that of the control, and total gas production of ginger extract was highest (p<0.05. The methane emission was highest (p<0.05 at control, but lowest (p<0.05 at garlic extract which was reduced to about 20% of methane emission (40.2 vs 32.5 ml/g DM. Other plant extracts also resulted in a decrease in methane emissions (wormwood; 8%, onion; 16%, ginger; 16.7%, mandarin orange; 12%, honeysuckle; 12.2%. Total VFAs concentration and pH were not influenced by the addition of plant extracts. Acetate to propionate ratios from garlic and ginger extracts addition samples were lower (p<0.05, 3.36 and 3.38 vs 3.53 than that of the control. Real-time PCR indicted that the ciliate-associated methanogen population in all added plant extracts decreased more than that of the control, while the fibrolytic bacteria population increased. In particular, the F. succinogens

  10. Phenotypic characterisation of cell populations in the brains of horses experimentally infected with West Nile virus.

    Science.gov (United States)

    Delcambre, G H; Liu, J; Streit, W J; Shaw, G P J; Vallario, K; Herrington, J; Wenzlow, N; Barr, K L; Long, M T

    2017-11-01

    West Nile virus (WNV), a mosquito borne member of the Flaviviridae, is one of the most commonly diagnosed agents of viral encephalitis in horses and people worldwide. A cassette of markers for formalin-fixed paraffin-embedded tissue and an archive of tissues from experimental infections in the horse were used to investigate the equine neuroimmune response to WNV meningoencephalomyelitis to phenotype the early response to WNV infection in the horse. Quantitative analysis using archived tissue from experimentally infected horses. The thalamus and hindbrain from 2 groups of 6 horses were compared and consisted of a culture positive tissues from WNV experimentally horses, in the other, normal horses. Formalin-fixed paraffin-embedded tissue from the thalamus and hindbrain were immunolabeled for microglia, astrocytes, B cells, macrophages/neutrophils, CD3 + T cells. Fresh frozen tissues were immunolabeled for CD4 + and CD8 + T lymphocyte cell markers. Cell counts were obtained using a computer software program. Differences, after meeting assumptions of abnormality, were computed using a general linear model with a Tukey test (Phorses, Iba-1 + microglia, CD3 + T lymphocyte and MAC387 + macrophage staining were significantly increased. The T cell response for the WNV-challenged horses was mixed, composed of CD4 + and CD8 + T lymphocytes. A limited astrocyte response was also observed in WNV-challenged horses, and MAC387 + and B cells were the least abundant cell populations. The results of this study were limited by a single collection time post-infection. Furthermore, a comprehensive analysis of cellular phenotypes is needed for naturally infected horses. Unfortunately, in clinical horses, there is high variability of sampling in terms of days post-infection and tissue handling. The data show that WNV-challenged horses recruit a mixed T cell population at the onset of neurologic disease. © 2017 EVJ Ltd.

  11. Optimization of preventive maintenance cycle based on experimental feedback in nuclear power plants

    International Nuclear Information System (INIS)

    Shi Jie

    2010-01-01

    The preventive replacement method based on the experimental feedback was introduced. In this method, the initial preventive replacement cycle was acquired by expert votes. The preventive replacement cycle combined with the operation experience of the equipment was gained by means of Bayesian theorem. The Optimized preventive replacement cycle can be acquired by comparing the two probabilities that no fault occurs within the cycle. This method was tested on the switches which were used in Daya Bay Nuclear Power Plant and the results indicated its validity. (authors)

  12. Offgas system particulate cleaning test and evaluation for the process experimental pilot plant

    International Nuclear Information System (INIS)

    Ayers, A.L. Jr.; Gale, L.G.; Stermer, D.L.

    1990-01-01

    The process experimental pilot plant (PREPP) incinerates mixed solid waste. The exhaust gas is processed through a wet offgas cleaning system. Rapid loading of the exhaust filters has been a problem and an important contributing factor is the use of quench solution containing a relatively high concentration of dissolved solids. The dissolved solids are released as a submicron particulate when the quench solution evaporates. A series of tests were performed to better identify the nature of the problem and explore solutions to the problem involving modifications to the quench process

  13. Reprocessing fuel from the Southwest Experimental Fast Oxide Reactor at the Savannah River Plant

    International Nuclear Information System (INIS)

    Gray, L.W.; Campbell, T.G.

    1985-11-01

    The irradiated fuel, reject fuel tubes, and fuel fabrication scrap from the Southwest Experimental Fast Oxide Reactor (SEFOR) were transferred to the Savannah River Plant (SRP) for uranium and plutonium recovery. The unirradiated material was declad and dissolved at SRP; dissolution was accomplished in concentrated nitric acid without the addition of fluoride. The irradiated fuel was declad at Atomics International and repacked in aluminum. The fuel and aluminum cans were dissolved at SRP using nitric acid catalyzed by mercuric nitrate. As this fuel was dissolved in nongeometrically favorable tanks, boron was used as a soluble neutron poison

  14. Experimental Research of Reliability of Plant Stress State Detection by Laser-Induced Fluorescence Method

    Directory of Open Access Journals (Sweden)

    Yury Fedotov

    2016-01-01

    Full Text Available Experimental laboratory investigations of the laser-induced fluorescence spectra of watercress and lawn grass were conducted. The fluorescence spectra were excited by YAG:Nd laser emitting at 532 nm. It was established that the influence of stress caused by mechanical damage, overwatering, and soil pollution is manifested in changes of the spectra shapes. The mean values and confidence intervals for the ratio of two fluorescence maxima near 685 and 740 nm were estimated. It is presented that the fluorescence ratio could be considered a reliable characteristic of plant stress state.

  15. Offgas system particulate cleaning test and evaluation for the Process Experimental Pilot Plant

    International Nuclear Information System (INIS)

    Ayers, A.L. Jr.; Gale, L.G.; Stermer, D.L.

    1990-01-01

    The Process Experimental Pilot Plant (PREPP) incinerates mixed solid waste. The exhaust gas is processed through a wet offgas cleaning system. Rapid loading of the exhaust filters has been a problem and an important contributing factor is the use of a quench solution containing a relatively high concentration of dissolved solids. The dissolved solids are released as a submicron particulate when the quench solution evaporates. A series of tests were performed to better identify the nature of the problem and explore solutions to the problem involving modifications to the quench process. 2 refs., 7 figs

  16. Quality Assurance Program Plan for the Waste Isolation Pilot Plant Experimental-Waste Characterization Program

    International Nuclear Information System (INIS)

    1991-01-01

    This Quality Assurance Program Plan (QAPP) identifies the quality of data necessary to meet the specific objectives associated with the Department of Energy (DOE) Waste Isolation Pilot Plant (WIPP) Experimental-Waste Characterization Program (the Program). This experimental-waste characterization program is only one part of the WIPP Test Phase, both in the short- and long-term, to quantify and evaluate the characteristics and behavior of transuranic (TRU) wastes in the repository environment. Other parts include the bin-scale and alcove tests, drum-scale tests, and laboratory experiments. In simplified terms, the purpose of the Program is to provide chemical, physical, and radiochemical data describing the characteristics of the wastes that will be emplaced in the WIPP, while the remaining WIPP Test Phase is directed at examining the behavior of these wastes in the repository environment. 50 refs., 35 figs., 33 tabs

  17. Range expansions transition from pulled to pushed waves with increasing cooperativity in an experimental microbial population

    Science.gov (United States)

    Gandhi, Saurabh; Yurtsev, Eugene; Korolev, Kirill; Gore, Jeff

    Range expansions are becoming more frequent due to environmental changes and rare long distance dispersal, often facilitated by anthropogenic activities. Simple models in theoretical ecology explain many emergent properties of range expansions, such as a constant expansion velocity, in terms of organism-level properties such as growth and dispersal rates. Testing these quantitative predictions in natural populations is difficult because of large environmental variability. Here, we used a controlled microbial model system to study range expansions of populations with and without intra-specific cooperativity. For non-cooperative growth, the expansion dynamics were dominated by population growth at the low-density front, which pulled the expansion forward. We found these expansions to be in close quantitative agreement with the classical theory of pulled waves by Fisher and Skellam, suitably adapted to our experimental system. However, as cooperativity increased, the expansions transitioned to being pushed, i.e. controlled by growth in the bulk as well as in the front. Although both pulled and pushed waves expand at a constant velocity and appear otherwise similar, their distinct dynamics leads to very different evolutionary consequences. Given the prevalence of cooperative growth in nature, understanding the effects of cooperativity is essential to managing invading species and understanding their evolution.

  18. Population History and Pathways of Spread of the Plant Pathogen Phytophthora plurivora

    Science.gov (United States)

    Schoebel, Corine N.; Stewart, Jane; Gruenwald, Niklaus J.; Rigling, Daniel; Prospero, Simone

    2014-01-01

    Human activity has been shown to considerably affect the spread of dangerous pests and pathogens worldwide. Therefore, strict regulations of international trade exist for particularly harmful pathogenic organisms. Phytophthora plurivora, which is not subject to regulations, is a plant pathogen frequently found on a broad range of host species, both in natural and artificial environments. It is supposed to be native to Europe while resident populations are also present in the US. We characterized a hierarchical sample of isolates from Europe and the US and conducted coalescent-, migration, and population genetic analysis of sequence and microsatellite data, to determine the pathways of spread and the demographic history of this pathogen. We found P. plurivora populations to be moderately diverse but not geographically structured. High levels of gene flow were observed within Europe and unidirectional from Europe to the US. Coalescent analyses revealed a signal of a recent expansion of the global P. plurivora population. Our study shows that P. plurivora has most likely been spread around the world by nursery trade of diseased plant material. In particular, P. plurivora was introduced into the US from Europe. International trade has allowed the pathogen to colonize new environments and/or hosts, resulting in population growth. PMID:24427303

  19. ASSESSMENT OF THE FUKUSIMA NUCLEAR POWER PLANT ACCIDENT CONSEQUENCES BY THE POPULATION IN THE FAR EAST

    Directory of Open Access Journals (Sweden)

    G. V. Arkhangelskaya

    2012-01-01

    Full Text Available The article analyzes the attitude of the population in the five regions of the Far East to the consequences of the accident at the Fukushimai nuclear power plant, as well as the issues of informing about the accident. The analysis of public opinion is based on the data obtained by anonymous questionnaire survey performed in November 2011. In spite of the rather active informing and objective information on the absence of the contamination, most of the population of the Russian Far East believes that radioactive contamination is presented in the areas of their residence, and the main cause of this contamination is the nuclear accident in Japan.

  20. Experimental investigation between attentional-resource effectiveness and perception and diagnosis in nuclear power plants

    International Nuclear Information System (INIS)

    Ha, Jun Su; Seong, Poong Hyun

    2014-01-01

    Highlights: • Effectiveness in information searching is measured by two eye-tracking measures. • The relationship between the effectiveness and perception and diagnosis is addressed. • An experimental study is conducted to investigate the relationship. • The experimental results show close correlation. • The eye-tracking measures as inferential measures for perception and diagnosis. - Abstract: Eye-tracking-based measures of attentional-resource effectiveness in information searching such as FIR (fixation to importance ratio) and SAE (selective attention effectiveness) have been developed based on cost-benefit principles. The relationship between the eye-tracking-based measures and perception and diagnosis of operators during operating tasks in main control rooms (MCRs) of nuclear power plants (NPPs) is investigated with experimental studies. The FIR and the SAE, which represent how effectively an operator attends to important information sources, are used as measures of the effectiveness in information searching. Perception failure rate (PFR) and diagnosis score (DS) are used as measures of perception and diagnosis, respectively. Experimental results show that the FIR and the SAE correlate closely with the PFR and the DS, respectively. It is concluded that the FIR and the SAE can be used as inferential measures of perception and diagnosis for human factors in NPP MCRs

  1. Experimental investigation between attentional-resource effectiveness and perception and diagnosis in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Jun Su, E-mail: junsu.ha@kustar.ac.ae [Nuclear Engineering Department, Khalifa University of Science, Technology and Research, P.O. Box 127788, Abu Dhabi (United Arab Emirates); Seong, Poong Hyun, E-mail: phseong@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2014-10-15

    Highlights: • Effectiveness in information searching is measured by two eye-tracking measures. • The relationship between the effectiveness and perception and diagnosis is addressed. • An experimental study is conducted to investigate the relationship. • The experimental results show close correlation. • The eye-tracking measures as inferential measures for perception and diagnosis. - Abstract: Eye-tracking-based measures of attentional-resource effectiveness in information searching such as FIR (fixation to importance ratio) and SAE (selective attention effectiveness) have been developed based on cost-benefit principles. The relationship between the eye-tracking-based measures and perception and diagnosis of operators during operating tasks in main control rooms (MCRs) of nuclear power plants (NPPs) is investigated with experimental studies. The FIR and the SAE, which represent how effectively an operator attends to important information sources, are used as measures of the effectiveness in information searching. Perception failure rate (PFR) and diagnosis score (DS) are used as measures of perception and diagnosis, respectively. Experimental results show that the FIR and the SAE correlate closely with the PFR and the DS, respectively. It is concluded that the FIR and the SAE can be used as inferential measures of perception and diagnosis for human factors in NPP MCRs.

  2. A below-ground herbivore shapes root defensive chemistry in natural plant populations.

    Science.gov (United States)

    Huber, Meret; Bont, Zoe; Fricke, Julia; Brillatz, Théo; Aziz, Zohra; Gershenzon, Jonathan; Erb, Matthias

    2016-03-30

    Plants display extensive intraspecific variation in secondary metabolites. However, the selective forces shaping this diversity remain often unknown, especially below ground. Using Taraxacum officinale and its major native insect root herbivore Melolontha melolontha, we tested whether below-ground herbivores drive intraspecific variation in root secondary metabolites. We found that high M. melolontha infestation levels over recent decades are associated with high concentrations of major root latex secondary metabolites across 21 central European T. officinale field populations. By cultivating offspring of these populations, we show that both heritable variation and phenotypic plasticity contribute to the observed differences. Furthermore, we demonstrate that the production of the sesquiterpene lactone taraxinic acid β-D-glucopyranosyl ester (TA-G) is costly in the absence, but beneficial in the presence of M. melolontha, resulting in divergent selection of TA-G. Our results highlight the role of soil-dwelling insects for the evolution of plant defences in nature. © 2016 The Author(s).

  3. Influence of small hydropower plants on brown trout (Salmo trutta L. population in Mislinja River

    Directory of Open Access Journals (Sweden)

    Blaž Cokan

    2013-12-01

    Full Text Available The brown trout (Salmo trutta L. in the Mislinja River has been endangered for years because of small hydroelectric power plants. To find out how they are affecting the population of the brown trout in the Mislinja River, we conducted a sampling of the brown trout, using a generating set. We measured the length and weight of all caught specimens and analysed the obtained data. The results are presented in this paper, e.g., biomass, estimations of abundance, average weight, average length and number of captured brown trout. We discovered that the population of the brown trout has decreased in all the sections where water has been taken away for small hydroelectric power plants.

  4. Experimental fact-finding in CFB biomass gasification for ECN's 500 kWth pilot-plant

    NARCIS (Netherlands)

    Kersten, Sascha R.A.; Prins, W.; van der Drift, A.; van Swaaij, Willibrordus Petrus Maria

    2003-01-01

    CFB biomass gasification has been studied by experimentation with ECN's pilot facility and a cold-flow model of this plant. Data obtained by normal operation of this plant and the results of some special experiments have provided new insight into the behavior of circulating fluidized bed reactors

  5. Pilot plant SERSE: Description and results of the experimental tests under treatment of simulated chemical liquid waste

    International Nuclear Information System (INIS)

    Calle, C.; Gili, M.; Luce, A.; Marrocchelli, A.; Pietrelli, L.; Troiani, F.

    1989-11-01

    The chemical processes for the selective separation of the actinides and long lived fission products from aged liquid wastes is described. The SERSE pilot plant is a cold facility which has been designed, by ENEA, for the engineering scale demonstration of the chemical separation processes. The experimental tests carried out in the plant are described and the results confirm the laboratory data. (author)

  6. Habitat fragmentation, vole population fluctuations, and the ROMPA hypothesis: An experimental test using model landscapes.

    Science.gov (United States)

    Batzli, George O

    2016-11-01

    Increased habitat fragmentation leads to smaller size of habitat patches and to greater distance between patches. The ROMPA hypothesis (ratio of optimal to marginal patch area) uniquely links vole population fluctuations to the composition of the landscape. It states that as ROMPA decreases (fragmentation increases), vole population fluctuations will increase (including the tendency to display multi-annual cycles in abundance) because decreased proportions of optimal habitat result in greater population declines and longer recovery time after a harsh season. To date, only comparative observations in the field have supported the hypothesis. This paper reports the results of the first experimental test. I used prairie voles, Microtus ochrogaster, and mowed grassland to create model landscapes with 3 levels of ROMPA (high with 25% mowed, medium with 50% mowed and low with 75% mowed). As ROMPA decreased, distances between patches of favorable habitat (high cover) increased owing to a greater proportion of unfavorable (mowed) habitat. Results from the first year with intensive live trapping indicated that the preconditions for operation of the hypothesis existed (inversely density dependent emigration and, as ROMPA decreased, increased per capita mortality and decreased per capita movement between optimal patches). Nevertheless, contrary to the prediction of the hypothesis that populations in landscapes with high ROMPA should have the lowest variability, 5 years of trapping indicated that variability was lowest with medium ROMPA. The design of field experiments may never be perfect, but these results indicate that the ROMPA hypothesis needs further rigorous testing. © 2016 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

  7. Effect of Drought on Herbivore-Induced Plant Gene Expression: Population Comparison for Range Limit Inferences

    Directory of Open Access Journals (Sweden)

    Gunbharpur Singh Gill

    2016-03-01

    Full Text Available Low elevation “trailing edge” range margin populations typically face increases in both abiotic and biotic stressors that may contribute to range limit development. We hypothesize that selection may act on ABA and JA signaling pathways for more stable expression needed for range expansion, but that antagonistic crosstalk prevents their simultaneous co-option. To test this hypothesis, we compared high and low elevation populations of Boechera stricta that have diverged with respect to constitutive levels of glucosinolate defenses and root:shoot ratios; neither population has high levels of both traits. If constraints imposed by antagonistic signaling underlie this divergence, one would predict that high constitutive levels of traits would coincide with lower plasticity. To test this prediction, we compared the genetically diverged populations in a double challenge drought-herbivory growth chamber experiment. Although a glucosinolate defense response to the generalist insect herbivore Spodoptera exigua was attenuated under drought conditions, the plastic defense response did not differ significantly between populations. Similarly, although several potential drought tolerance traits were measured, only stomatal aperture behavior, as measured by carbon isotope ratios, was less plastic as predicted in the high elevation population. However, RNAseq results on a small subset of plants indicated differential expression of relevant genes between populations as predicted. We suggest that the ambiguity in our results stems from a weaker link between the pathways and the functional traits compared to transcripts.

  8. Effects of environmental radiation of Kori nuclear power plant on the human population

    International Nuclear Information System (INIS)

    Kim, Y.J.

    1979-01-01

    In order to clarify and protect the effects of environmental radiation according to the operation of Kori nuclear power plant on human population, the base line survey for the human monitoring, the fauna of land nocturnal insects, and the karyotypes of amphibian species which have been living around the power plant site were carried out. ''Kilchunri'' population which took for the human monitoring lie within a 2km distance from power plant site. Human monitoring, house and food characteristics, individual experience of X-ray exposures, human chromosome analysis and fauna of nocturnal land insects were surveyed and expressed in numerical tables. Chromosome number obtained from the amphibia which were collected around the power plant area was as follows; Kaloula borealis 2N=30, Rana amurensis 2N=26, Rana dybouskii 2N=24, Rana rugosa 2N=26, Rana migromaculata 2N=26, Rana plancyi 2N=26, Bombina orientalis 2N=24, Hyla arborea 2N=24, Bufo stejnegeri 2N=22, and Bufo bufo 2N=22. (author)

  9. Final report on effects of environmental radiation of Kori nuclear power plant on human population

    International Nuclear Information System (INIS)

    Kim, Y.J.; Kim, J.B.; Chung, K.H.; Lee, K.S.; Kim, S.R.; Yang, S.Y.

    1980-01-01

    In order to clarify and protect the effects of environmental radiation according to the operation of Kori nuclear power plant on the human population, the base line survey for the human monitoring, human life habits, expected individual exposure dose, frequencies of chromosomal aberration, gene frequencies and karyotypes in amphibia, fauna, and radiation sensitivities in microorganisms which have been living around the power plant site were carried out. Kilchonri population which took for the human monitoring lie within a 2 km distance from the power plant site. Human monitoring, house and food characteristics, individual experience of x-ray exposures, human chromosome analysis and fauna were surveyed and expressed in numerical tables. Chromosome number obtained from the amphibia which were collected around the power plant area was as follows: Kaloula borealis 2N=30, Rana amurensis 2N=26, Rana dybouskii 2N=24, Rana rugosa 2N=26, Rana nigromaculata 2N=26, Rana plancyi 2N=26, Bombina orientalis 2N=24, Hyla arborea 2N=24, Bufo stejnegeri 2N=22, Bufo bufo 2N=22. (author)

  10. Effects of radiation exposure on plant populations and radiation protection of the environment

    Energy Technology Data Exchange (ETDEWEB)

    Geras' kin, St.A.; Dikarev, V.G.; Oudalova, A.A.; Vasiliev, D.V.; Dikareva, N.S.; Baykova, T.A. [Russian Institute of Agricultural Radiology and Agroecology, Obninsk (Russian Federation); Evseeva, T.I. [Institute of Biology, Komi Scientific Center, Ural Div. RAS, Syktyvkar (Russian Federation)

    2006-07-01

    The results of long-term field experiments in the 30-km Chernobyl NPP zone, In the vicinity of the radioactive wastes storage facility (Leningrad Region), at radium production industry storage cell (the Komi Republic), and in Bryansk Region affected by the ChNPP accident that have been carried out on different species of wild and agricultural plants are discussed. These findings indicate that plant populations growing in areas with relatively low levels of pollution are characterized by the increased level of both cytogenetic disturbances and genetic diversity. The chronic low-dose exposure appears to be an ecological factor creating preconditions for possible changes in the genetic structure of a population. These processes have a genetic basis; therefore, an understanding changes at the genetic level should help in an identifying more complex changes at higher levels. The presented findings add to filling an important gap in our knowledge on remote effects in plant populations and ecosystems from man-made impact. (author)

  11. Effects of radiation exposure on plant populations and radiation protection of the environment

    International Nuclear Information System (INIS)

    Geras'kin, St.A.; Dikarev, V.G.; Oudalova, A.A.; Vasiliev, D.V.; Dikareva, N.S.; Baykova, T.A.; Evseeva, T.I.

    2006-01-01

    The results of long-term field experiments in the 30-km Chernobyl NPP zone, In the vicinity of the radioactive wastes storage facility (Leningrad Region), at radium production industry storage cell (the Komi Republic), and in Bryansk Region affected by the ChNPP accident that have been carried out on different species of wild and agricultural plants are discussed. These findings indicate that plant populations growing in areas with relatively low levels of pollution are characterized by the increased level of both cytogenetic disturbances and genetic diversity. The chronic low-dose exposure appears to be an ecological factor creating preconditions for possible changes in the genetic structure of a population. These processes have a genetic basis; therefore, an understanding changes at the genetic level should help in an identifying more complex changes at higher levels. The presented findings add to filling an important gap in our knowledge on remote effects in plant populations and ecosystems from man-made impact. (author)

  12. WITHIN-POPULATION GENETIC DIVERSITY OF CLIMBING PLANTS AND TREES IN A TEMPERATE FOREST IN CENTRAL CHILE

    OpenAIRE

    Torres-Díaz, Cristian; Ruiz, Eduardo; Salgado-Luarte, Cristian; Molina-Montenegro, Marco A; Gianoli, Ernesto

    2013-01-01

    The climbing habit is a key innovation in angiosperm evolution: climbing plant taxa have greater species richness than their non-climbing sister groups. It is considered that highly diversified clades should show increased among-population genetic differentiation. Less clear is the expected pattern regarding within-population genetic diversity in speciose lineages. We tested the hypothesis of greater within-population genetic diversity in climbing plants compared to trees in a temperate fores...

  13. Impact Of Different Time Planting In Soybeans And Neem Seed Extract Application To Insect Population On Rice Field

    OpenAIRE

    Tamrin Abdullah; Ahdin Gassa; Sri Nur Aminah Ngatimin; Nurariaty Agus And Abdul Fattah

    2015-01-01

    Abstract The purpose of research is to study impact of different time planting of soybean and neem seed extract application to pest insect population on rice field. The research was used Random Block Design in three treatment of insecticides application i.e neem seed extract together with rice planting neem seed extract on soybean 17 days after rice planting synthetic insecticides on 17 days after rice planting Delthametrin on soybean and Chlorpirifos on rice respectively. Research was conduc...

  14. Impact Of Different Time Planting In Soybeans And Neem Seed Extract Application To Insect Population On Rice Field

    OpenAIRE

    Abdullah, Tamrin; Gassa, Ahdin; Ngatimin, Sri Nur Aminah; Agus, Nurariaty; Fattah, Abdul

    2015-01-01

    The purpose of research is to study impact of different time planting of soybean and neem seed extract application to pest insect population on rice field. The research was used Random Block Design in three treatment of insecticides application i.e: neem seed extract together with rice planting, neem seed extract on soybean 17 days after rice planting, synthetic insecticides on 17 days after rice planting (Delthametrin on soybean and Chlorpirifos on rice), respectively. Research was conducted...

  15. Kainic Acid-Induced Excitotoxicity Experimental Model: Protective Merits of Natural Products and Plant Extracts

    Directory of Open Access Journals (Sweden)

    Nur Shafika Mohd Sairazi

    2015-01-01

    Full Text Available Excitotoxicity is well recognized as a major pathological process of neuronal death in neurodegenerative diseases involving the central nervous system (CNS. In the animal models of neurodegeneration, excitotoxicity is commonly induced experimentally by chemical convulsants, particularly kainic acid (KA. KA-induced excitotoxicity in rodent models has been shown to result in seizures, behavioral changes, oxidative stress, glial activation, inflammatory mediator production, endoplasmic reticulum stress, mitochondrial dysfunction, and selective neurodegeneration in the brain upon KA administration. Recently, there is an emerging trend to search for natural sources to combat against excitotoxicity-associated neurodegenerative diseases. Natural products and plant extracts had attracted a considerable amount of attention because of their reported beneficial effects on the CNS, particularly their neuroprotective effect against excitotoxicity. They provide significant reduction and/or protection against the development and progression of acute and chronic neurodegeneration. This indicates that natural products and plants extracts may be useful in protecting against excitotoxicity-associated neurodegeneration. Thus, targeting of multiple pathways simultaneously may be the strategy to maximize the neuroprotection effect. This review summarizes the mechanisms involved in KA-induced excitotoxicity and attempts to collate the various researches related to the protective effect of natural products and plant extracts in the KA model of neurodegeneration.

  16. No evidence of complementary water use along a plant species richness gradient in temperate experimental grasslands.

    Directory of Open Access Journals (Sweden)

    Dörte Bachmann

    Full Text Available Niche complementarity in resource use has been proposed as a key mechanism to explain the positive effects of increasing plant species richness on ecosystem processes, in particular on primary productivity. Since hardly any information is available for niche complementarity in water use, we tested the effects of plant diversity on spatial and temporal complementarity in water uptake in experimental grasslands by using stable water isotopes. We hypothesized that water uptake from deeper soil depths increases in more diverse compared to low diverse plant species mixtures. We labeled soil water in 8 cm (with 18O and 28 cm depth (with ²H three times during the 2011 growing season in 40 temperate grassland communities of varying species richness (2, 4, 8 and 16 species and functional group number and composition (legumes, grasses, tall herbs, small herbs. Stable isotope analyses of xylem and soil water allowed identifying the preferential depth of water uptake. Higher enrichment in 18O of xylem water than in ²H suggested that the main water uptake was in the upper soil layer. Furthermore, our results revealed no differences in root water uptake among communities with different species richness, different number of functional groups or with time. Thus, our results do not support the hypothesis of increased complementarity in water use in more diverse than in less diverse communities of temperate grassland species.

  17. Assessment of volatile organic compound removal by indoor plants-a novel experimental setup

    DEFF Research Database (Denmark)

    Dela Cruz, Majbrit; Müller, Renate; Svensmark, Bo

    2014-01-01

    plants which allows for an improved real-life simulation. Parameters such as relative humidity, air exchange rate and VOC concentration are controlled and can be varied to simulate different real-life settings. For example, toluene diffusion through a needle gave concentrations in the range of 0......Indoor plants can remove volatile organic compounds (VOCs) from the air. The majority of knowledge comes from laboratory studies where results cannot directly be transferred to real-life settings. The aim of this study was to develop an experimental test system to assess VOC removal by indoor.......10-2.35 μg/L with deviations from theoretical values of 3.2-10.5 %. Overall, the system proved to be functional for the assessment of VOC removal by indoor plants with Hedera helix reaching a toluene removal rate of up to 66.5 μg/m2/h. The mode of toluene exposure (semi-dynamic or dynamic) had a significant...

  18. Development step toward fusion power plant and role of experimental reactor ITER

    International Nuclear Information System (INIS)

    Hiwatari, Ryouji; Asaoka, Yoshiyuki; Okano, Kunihiko

    2005-01-01

    The development of fusion energy is going into the experimental reactor stage, and the thermal energy from the fusion reaction will be generated in a plant scale through the ITER (International Thermonuclear Experimental Reactor) project. The remaining critical issue toward the realization of fusion energy is to map out the development strategy. Recently early realization approach as for the fusion energy development is being discussed in Japan, Europe, and the United States. This approach implies that the devices for a Demo reactor and a proto-type reactor as seen in the fast breeder reactor are combined into a single device in order to advance the fusion energy development. On the other hand, a clear development road map for fusion energy hasn't been suggested yet, and whether that early realization approach is feasible or not is still ambiguous. In order to realize the fusion energy as an user-friendly energy system, the suggestion of the development missions and the road map from the user-side point of view is instructive not only to Japanese but also to other country's development policy after the ITER project. In this report, first of all, the development missions from the user's point of view have been structured. Second, the development target required to demonstrate net electric generation and to introduce the fusion energy into the market is investigated, respectively. This investigation reveals that the completion of the ITER reference operation gives the outlook toward the demonstration of net electric generation and that the completion of the ITER advanced operation gives the possibility to introduce the fusion energy into the market. At last, the electric demonstration power plant Demo-CREST and the commercial power plant CREST are proposed to construct the development road map for fusion energy. (author)

  19. LOD significance thresholds for QTL analysis in experimental populations of diploid species

    Science.gov (United States)

    Van Ooijen JW

    1999-11-01

    Linkage analysis with molecular genetic markers is a very powerful tool in the biological research of quantitative traits. The lack of an easy way to know what areas of the genome can be designated as statistically significant for containing a gene affecting the quantitative trait of interest hampers the important prediction of the rate of false positives. In this paper four tables, obtained by large-scale simulations, are presented that can be used with a simple formula to get the false-positives rate for analyses of the standard types of experimental populations with diploid species with any size of genome. A new definition of the term 'suggestive linkage' is proposed that allows a more objective comparison of results across species.

  20. Adaptive transgenerational plasticity in plants: case studies, mechanisms, and implications for natural populations

    Directory of Open Access Journals (Sweden)

    Jacob J. Herman

    2011-12-01

    Full Text Available Plants respond to environmental conditions not only by plastic changes to their own development and physiology, but also by altering the phenotypes expressed by their offspring. This transgenerational plasticity was initially considered to entail only negative effects of stressful parental environments, such as production of smaller seeds by resource- or temperature-stressed parent plants, and was therefore viewed as environmental noise. Recent evolutionary ecology studies have shown that in some cases, these inherited environmental effects can include specific growth adjustments that are functionally adaptive to the parental conditions that induced them, which can range from contrasting states of controlled laboratory environments to the complex habitat variation encountered by natural plant populations. Preliminary findings suggest that adaptive transgenerational effects can be transmitted by means of diverse mechanisms including changes to seed provisioning and biochemistry, and epigenetic modifications such as DNA methylation that can persist across multiple generations. These non-genetically inherited adaptations can influence the ecological breadth and evolutionary dynamics of plant taxa and promote the spread of invasive plants. Interdisciplinary studies that join mechanistic and evolutionary ecology approaches will be an important source of future insights.

  1. Adaptive transgenerational plasticity in plants: case studies, mechanisms, and implications for natural populations.

    Science.gov (United States)

    Herman, Jacob J; Sultan, Sonia E

    2011-01-01

    Plants respond to environmental conditions not only by plastic changes to their own development and physiology, but also by altering the phenotypes expressed by their offspring. This transgenerational plasticity was initially considered to entail only negative effects of stressful parental environments, such as production of smaller seeds by resource- or temperature-stressed parent plants, and was therefore viewed as environmental noise. Recent evolutionary ecology studies have shown that in some cases, these inherited environmental effects can include specific growth adjustments that are functionally adaptive to the parental conditions that induced them, which can range from contrasting states of controlled laboratory environments to the complex habitat variation encountered by natural plant populations. Preliminary findings suggest that adaptive transgenerational effects can be transmitted by means of diverse mechanisms including changes to seed provisioning and biochemistry, and epigenetic modifications such as DNA methylation that can persist across multiple generations. These non-genetically inherited adaptations can influence the ecological breadth and evolutionary dynamics of plant taxa and promote the spread of invasive plants. Interdisciplinary studies that join mechanistic and evolutionary ecology approaches will be an important source of future insights.

  2. Energetic efficiency analysis of the agricultural biogas plant in 250 kWe experimental installation

    International Nuclear Information System (INIS)

    Dach, Jacek; Boniecki, Piotr; Przybył, Jacek; Janczak, Damian; Lewicki, Andrzej; Czekała, Wojciech; Witaszek, Kamil; Rodríguez Carmona, Pablo César; Cieślik, Marta

    2014-01-01

    European direction of energy development has been already set few years ago. Proper waste management is not just a fashion trend of the wealthy European countries – it has become a legal requirement. Processing of the biowaste into the biogas is one of the most effective technologies providing to obtain a “green” energy and improvement of the environment. Construction of small and cheap agricultural biogas plants, like in case of Poznan University of Life Sciences (PULS) experimental station Przybroda, is one of the best directions of dissemination of this biowaste valorization technology. The aim of this paper was to investigate the biogas efficiency of the substrates available in PULS experimental farm Przybroda (cattle manure, maize silage). The results have shown that the most energetic valuable substrate is maize silage with cumulative biogas yield 218.4 m 3 /Mg FM (almost 3 times more than cattle manure). With yearly substrate availability on the Przybroda farm, total amount of biomethane produced is 521,440 m 3 from maize silage and 23,615 m 3 from cattle manure. It allows to obtain 2212.38 MWh/year of electric energy as well as 2428.22 MWh/year thermal energy production. The calculated electric energy power was 0.270 MW. - Highlights: • Research on biogas efficiency from different substrates has been made. • Estimation of energy produced from own substrates was done. • Power of biogas plant on experimental farm calculated as 0.270 MW e and 0.296 MW t

  3. Using soil seed banks to assess temporal patterns of genetic variation in invasive plant populations.

    Science.gov (United States)

    Fennell, Mark; Gallagher, Tommy; Vintro, Luis Leon; Osborne, Bruce

    2014-05-01

    Most research on the genetics of invasive plant species has focused on analyzing spatial differences among existing populations. Using a long-established Gunnera tinctoria population from Ireland, we evaluated the potential of using plants derived from seeds associated with different soil layers to track genetic variation through time. This species and site were chosen because (1) G. tinctoria produces a large and persistent seed bank; (2) it has been present in this locality, Sraheens, for ∼90 years; (3) the soil is largely undisturbed; and (4) the soil's age can be reliably determined radiometrically at different depths. Amplified fragment length polymorphic markers (AFLPs) were used to assess differences in the genetic structure of 75 individuals sampled from both the standing population and from four soil layers, which spanned 18 cm (estimated at ∼90 years based on (210)Pb and (137)Cs dating). While there are difficulties in interpreting such data, including accounting for the effects of selection, seed loss, and seed migration, a clear pattern of lower total allele counts, percentage polymorphic loci, and genetic diversity was observed in deeper soils. The greatest percentage increase in the measured genetic variables occurred prior to the shift from the lag to the exponential range expansion phases and may be of adaptive significance. These findings highlight that seed banks in areas with long-established invasive populations can contain valuable genetic information relating to invasion processes and as such, should not be overlooked.

  4. Responsiveness of performance and morphological traits to experimental submergence predicts field distribution pattern of wetland plants

    NARCIS (Netherlands)

    Luo, Fang-Li; Huang, Lin; Lei, Ting; Xue, Wei; Li, Hong-Li; Yu, Fei-Hai; Cornelissen, J.H.C.

    2016-01-01

    Question: Plant trait mean values and trait responsiveness to different environmental regimes are both important determinants of plant field distribution, but the degree to which plant trait means vs trait responsiveness predict plant distribution has rarely been compared quantitatively. Because

  5. Health state of population in vicinity of the Mochovce nuclear power plant. Epidemiologic study

    International Nuclear Information System (INIS)

    Celko, M.; Durov, M.; Letkovicova, M.; Holy, R.; Sedliak, D.; Zrubec, M.; Kristufek, P.; Machata, M.; Prikazsky, V.; Rehak, R.; Stehlikova, B.; Vladar, M.

    1999-01-01

    Results of epidemiologic study of health state of population in vicinity of the Mochovce nuclear power plant (Slovak Republic) are presented. This report is reported under the headings: (1) Introduction; (2) Basic information about Mochovce NPP; (3) Assessment of population exposition by environmental factors; (4) Basic conceptions and principles of epidemiologic study; (5) Demography and health state of population; (6) Characterisation of databases and data; (7) Description of demographic and health indicators; (8) Calculation of demographic and health indicators in vicinity of the Mochovce NPP and in control areas; (9) Calculated indicators; (10) Statistical methods and evaluation of calculated indicators; (11) Summary and conclusions; (12) References; Appendixes: Literature review of similar epidemiologic studies; Quantities and units in radiation protection; Definitions of indicators calculation - specification of method

  6. Plant community structure regulates responses of prairie soil respiration to decadal experimental warming.

    Science.gov (United States)

    Xu, Xia; Shi, Zheng; Li, Dejun; Zhou, Xuhui; Sherry, Rebecca A; Luo, Yiqi

    2015-10-01

    Soil respiration is recognized to be influenced by temperature, moisture, and ecosystem production. However, little is known about how plant community structure regulates responses of soil respiration to climate change. Here, we used a 13-year field warming experiment to explore the mechanisms underlying plant community regulation on feedbacks of soil respiration to climate change in a tallgrass prairie in Oklahoma, USA. Infrared heaters were used to elevate temperature about 2 °C since November 1999. Annual clipping was used to mimic hay harvest. Our results showed that experimental warming significantly increased soil respiration approximately from 10% in the first 7 years (2000-2006) to 30% in the next 6 years (2007-2012). The two-stage warming stimulation of soil respiration was closely related to warming-induced increases in ecosystem production over the years. Moreover, we found that across the 13 years, warming-induced increases in soil respiration were positively affected by the proportion of aboveground net primary production (ANPP) contributed by C3 forbs. Functional composition of the plant community regulated warming-induced increases in soil respiration through the quantity and quality of organic matter inputs to soil and the amount of photosynthetic carbon (C) allocated belowground. Clipping, the interaction of clipping with warming, and warming-induced changes in soil temperature and moisture all had little effect on soil respiration over the years (all P > 0.05). Our results suggest that climate warming may drive an increase in soil respiration through altering composition of plant communities in grassland ecosystems. © 2015 John Wiley & Sons Ltd.

  7. Evaluation of population density and distribution criteria in nuclear power plant siting

    International Nuclear Information System (INIS)

    Young, M.

    1994-06-01

    The NRC has proposed revisions to 10 CFR 100 which include the codification of nuclear reactor site population density limits to 500 people per square mile, at the siting stage, averaged over any radial distance out to 30 miles, and 1,000 people per square mile within the 40-year lifetime of a nuclear plant. This study examined whether there are less restrictive alternative population density and/or distribution criteria which would provide equivalent or better protection to human health in the unlikely event of a nuclear accident. This study did not attempt to directly address the issue of actual population density limits because there are no US risk standards established for the evaluation of population density limits. Calculations were performed using source terms for both a current generation light water reactor (LWR) and an advanced light water reactor (ALWR) design. The results of this study suggest that measures which address the distribution of the population density, including emergency response conditions, could result in lower average individual risks to the public than the proposed guidelines that require controlling average population density. Studies also indicate that an exclusion zone size, determined by emergency response conditions and reactor design (power level and safety features), would better serve to protect public health than a rigid standard applied to all sites

  8. The influence of geographic location on population exposure to emissions from power plants throughout China

    Energy Technology Data Exchange (ETDEWEB)

    Ying Zhou; Levy, J.I. [Harvard School of Public Health, Boston, MA (United States); Evans, J.S.; Hammitt, J.K. [Harvard Center for Risk Analysis, Boston, MA (United States)

    2006-04-15

    This analysis seeks to evaluate the influence of emission source location on population exposure in China to fine particles and sulfur dioxide. We use the concept of intake fraction, defined as the fraction of material or its precursor released from a source that is eventually inhaled or ingested by a population. We select 29 power-plant sites throughout China and estimate annual average intake fractions at each site, using identical source characteristics to isolate the influence of geographic location. In addition, we develop regression models to interpret the intake fraction values and allow for extrapolation to other sites. To model the concentration increase due to emissions from selected power plants, we used a detailed long-range atmospheric dispersion model, CALPUFF. Primary fine particles have the highest average intake fraction (1 x 10{sup -5}), followed by sulfur dioxide (5 x 10{sup -6}), sulfate from sulfur dioxide (4 x 10{sup -6}), and nitrate from nitrogen oxides (4 x 10{sup -6}). For all pollutants, the intake fractions span approximately an order of magnitude across sites. In the regression analysis, the independent variables are meteorological proxies (such as climate region and precipitation) and population at various distances from the source. We find that population terms can explain a substantial percentage of variability in the intake fraction for all pollutants (R{sup 2} between 0.86 and 0.95 across pollutants), with a significant modifying influence of meteorological regime. Near-source population is more important for primary coarse particles while population at medium to long distance is more important for primary fine particles and secondary particles. A significant portion of intake fraction (especially for secondary particles and primary fine particles) occurs beyond 500 km of the source, emphasizing the need for detailed long-range dispersion modeling. These findings demonstrate that intake fractions for power plants in China can be

  9. The influence of geographic location on population exposure to emissions from power plants throughout China

    International Nuclear Information System (INIS)

    Ying Zhou; Levy, J.I.; Evans, J.S.; Hammitt, J.K.

    2006-01-01

    This analysis seeks to evaluate the influence of emission source location on population exposure in China to fine particles and sulfur dioxide. We use the concept of intake fraction, defined as the fraction of material or its precursor released from a source that is eventually inhaled or ingested by a population. We select 29 power-plant sites throughout China and estimate annual average intake fractions at each site, using identical source characteristics to isolate the influence of geographic location. In addition, we develop regression models to interpret the intake fraction values and allow for extrapolation to other sites. To model the concentration increase due to emissions from selected power plants, we used a detailed long-range atmospheric dispersion model, CALPUFF. Primary fine particles have the highest average intake fraction (1 x 10 -5 ), followed by sulfur dioxide (5 x 10 -6 ), sulfate from sulfur dioxide (4 x 10 -6 ), and nitrate from nitrogen oxides (4 x 10 -6 ). For all pollutants, the intake fractions span approximately an order of magnitude across sites. In the regression analysis, the independent variables are meteorological proxies (such as climate region and precipitation) and population at various distances from the source. We find that population terms can explain a substantial percentage of variability in the intake fraction for all pollutants (R 2 between 0.86 and 0.95 across pollutants), with a significant modifying influence of meteorological regime. Near-source population is more important for primary coarse particles while population at medium to long distance is more important for primary fine particles and secondary particles. A significant portion of intake fraction (especially for secondary particles and primary fine particles) occurs beyond 500 km of the source, emphasizing the need for detailed long-range dispersion modeling. These findings demonstrate that intake fractions for power plants in China can be estimated with

  10. Experimental results from a pilot plant for the ammonia removal from drinkable supply

    International Nuclear Information System (INIS)

    Bruno, G.; Di Sabatino, B.

    2001-01-01

    Ion exchange represents a valid alternative to chlorination for ammonia removal from drinking water, because it allows to prevent the main disadvantage of the chlorination process, i.e. the production of chlorinated organic compounds, which may be cancerous, occurring when the water to be treated contains organic substances. Ion exchange can be carried out by means of natural zeolites. Zeolites are microcrystalline aluminosilicates minerals, being common constituents of the quaternary tuffs emitted by volcanic alkaline - potassic districts of Lazio (Italy). Particularly, phyllipsite and chabasite were selected among several zeolites species because of their high specific selectivity with ammonium ion and high theoretical exchange capacity (3.5 meq/g). The concentrations of such mineral in the rocks employed were about 40-50%. A preliminary experimental step was performed in order to select the main operative parameters. Then, a pilot plant was built up at the 'Acquedotto Municipale' of Turin (Italy), made by filtration columns. A nitrifying biomass was observed to grow onto the zeolite granules, thus forming a combined chemical-biological system allowing a high removal efficiency to be attained throughout the experimental campaigns. The present paper deals with the results obtained from a two-year experimental investigation [it

  11. The influence of geographic location on population exposure to emissions from power plants throughout China

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Y.; Levy, J.I.; Evans, J.S.; Hammitt, J.K. [Harvard University, Boston, MA (United States). School of Public Health

    2006-04-15

    This analysis seeks to evaluate the influence of emission source location on population exposure in China to fine particles and sulfur dioxide. We use the concept of intake fraction, defined as the fraction of material or its precursor released from a source that is eventually inhaled or ingested by a population. We select 29 power-plant sites throughout China and estimate annual average intake fractions at each site, using identical source characteristics to isolate the influence of geographic location. In addition, we develop regression models to interpret the intake fraction values and allow for extrapolation to other sites. To model the concentration increase due to emissions from selected power plants, we used a detailed long-range atmospheric dispersion model, CALPUFF. Primary fine particles have the highest average intake fraction (1 x 10{sup -5}), followed by sulfur dioxide (5 x 10{sup -6}), sulfate from sulfur dioxide (4 x 10{sup -6}), and nitrate from nitrogen oxides (4 x 10{sup -6}). In the regression analysis, the independent variables are meteorological proxies (such as climate region and precipitation) and population at various distances from the source. We find that population terms can explain a substantial percentage of variability in the intake fraction for all pollutants, with a significant modifying influence of meteorological regime. Near-source population is more important for primary coarse particles while population at medium to long distance is more important for primary fine particles and secondary particles. A significant portion of intake fraction (especially for secondary particles and primary fine particles) occurs beyond 500 km of the source, emphasizing the need for detailed long-range dispersion modeling.

  12. Linking Native and Invader Traits Explains Native Spider Population Responses to Plant Invasion.

    Directory of Open Access Journals (Sweden)

    Jennifer N Smith

    Full Text Available Theoretically, the functional traits of native species should determine how natives respond to invader-driven changes. To explore this idea, we simulated a large-scale plant invasion using dead spotted knapweed (Centaurea stoebe stems to determine if native spiders' web-building behaviors could explain differences in spider population responses to structural changes arising from C. stoebe invasion. After two years, irregular web-spiders were >30 times more abundant and orb weavers were >23 times more abundant on simulated invasion plots compared to controls. Additionally, irregular web-spiders on simulated invasion plots built webs that were 4.4 times larger and 5.0 times more likely to capture prey, leading to >2-fold increases in recruitment. Orb-weavers showed no differences in web size or prey captures between treatments. Web-spider responses to simulated invasion mimicked patterns following natural invasions, confirming that C. stoebe's architecture is likely the primary attribute driving native spider responses to these invasions. Differences in spider responses were attributable to differences in web construction behaviors relative to historic web substrate constraints. Orb-weavers in this system constructed webs between multiple plants, so they were limited by the overall quantity of native substrates but not by the architecture of individual native plant species. Irregular web-spiders built their webs within individual plants and were greatly constrained by the diminutive architecture of native plant substrates, so they were limited both by quantity and quality of native substrates. Evaluating native species traits in the context of invader-driven change can explain invasion outcomes and help to identify factors limiting native populations.

  13. The biological model of postradiation restoration of plants on the organismic and population levels of organization

    International Nuclear Information System (INIS)

    Ivanishvili, N.I.; Gogebashvili, M.E.

    2012-01-01

    Full text : When studying postradiating restoration of plants, the question of working out of biological models for testing of biosystems' reliability has become rather urgent. It is known that each organization level of a live organism is characterized by certain mechanisms of postradiating restoration at the formation of various radiobiological reactions. For example, the basic processes at cellular, tissue and organism levels are reparation and regeneration whereas at cenosis level the leading processes are often the forms of population restoration. Besides, in spite of the fact that the population restoration at cenosis level is continuously inked with restoration at the lower organization levels, at this level the specific forms of restoration characterized for only this level are seen. It is natural that studying of the mechanisms of response to the influence of damaging factors needs new methodological approaches on various forms of population restoration with the use of adequate test systems. For this purpose the species of duckweed was used. It was seen that this test-system is characterized by the two levels of response to radiation influence. The first one - at a rather low level of radiation influence (up to 50Gy) when decrease in intensity of leaf growth as well as in colony formation was observed and the second one - at a high level of radiation influence (up to 200Gy) when a crushing of colonies took place and an increase in quantity of undeveloped plant leaves was seen. Thus, thanks to the step character of response of culture duckweed it becomes possible to definite quantity indicators for the investigated populations, not only at the influence of concrete physical and chemical factors but also at multifactorial influences that is often difficult to be calculated. It can be concluded that at the first level of damage an increase of plant resistance to unfavorable factors takes place that is due to the inhibition of growth processes

  14. Estimating population exposure to power plant emissions using CALPUFF: a case study in Beijing, China

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Y.; Levy, J.I.; Hammitt, J.K.; Evans, J.S. [Harvard University, Boston, MA (USA). School of Public Health, Landmark Center

    2003-02-01

    Power plants are significant emitters of precursor gases of fine particulate matter. To evaluate the public health risk posed by power plants, it is necessary to evaluate population exposure to different pollutants. The concept of intake fraction (the fraction of a pollutant emitted that is eventually inhaled or ingested by a population) has been proposed to provide a simple summary measure of the relationship between emissions and exposure. Currently available intake fraction estimates from developing countries used models that look only at the near field impacts, which may not capture the full impact of a pollution source. This case study demonstrated how the intake fraction of power plant emissions in China can be calculated using a detailed long-range atmospheric dispersion model, CALPUFF. It was found that the intake fraction of primary fine particles is roughly on the order of 10{sup -5}, while the intake fractions of sulfur dioxide, sulfate and nitrate are on the order of 10{sup -6}. These estimates are an order of magnitude higher than the US estimates. The authors also tested how sensitive the results were to key assumptions within the model. The size distribution of primary particles has a large impact on the intake fraction for primary particles while the background ammonia concentration is an important factor influencing the intake fraction of nitrate. The background ozone concentration has a moderate impact on the intake fraction of sulfate and nitrate.

  15. [Energy accumulation and allocation of main plant populations in Aneurolepidium chinense grassland in Songnen Plain].

    Science.gov (United States)

    Qu, Guohui; Wen, Mingzhang; Guo, Jixun

    2003-05-01

    The calorific value of plants is dependent on their biological characteristics and energy-containing materials. The allocation of calorific value in different organs of Aneurolepidium chinese, Calamagrostic epigejos, Puccinellia tenuiflora and Chloris virgata was inflorescence > leaf > stem > dead standing. The seasonal dynamics of standing crop energy of aboveground part of four plant populations showed single-peak curve, and the energy production was Aneurolepidium chinense > Calamagrostic epigejos > Chloris virgata > Puccinellia tenuiflora. Energy increasing rate showed double-peak curve, with the first peak at heading stage and the second peak at maturing stage of seeds. Energy increasing rate was negative at the final stage of growth. The horizontal distribution of energy of aboveground part was that the allocation ratio of different organs at different growth stages was different. There existed a similar trend for vertical distribution of energy among four plant populations, i.e., was the vertical distribution of energy of aboveground part showed a tower shape, with the maximum value in 10-30 cm height. The vertical distribution of energy of underground part showed an inverted tower shape from soil surface to deeper layer, with the maximum value in 0-10 cm depth. The standing crop energy of underground part was about 3-4 times than that of aboveground part.

  16. Construction of an experimental plot seeder of wheat planting and compare it by imported one

    Directory of Open Access Journals (Sweden)

    I Eskandari

    2016-09-01

    Full Text Available Introduction Researchers frequently include multiple cultivars and fertility levels in field experiments. Therefore, the experiments sowing operation must represent a considerable saving in time and labor, compared to hand sowing. Greater flexibility in experimental design and setup could be achieved by equipment that enables quick changes in the cultivar and fertilizer rates from one plot to the next. A satisfactory seed drill must distribute a given quantity of seed evenly over a predetermined length of coulter row, the coulters must be spaced at exact intervals and depth of sowing must be uniform. In a self-propelled type of plot seeder, no coulter should run in a wheel track as the compaction of the soil can cause observable differences in vigor between plants in such a row and those in un-compacted rows. The machine should sow in succession from a try in which a series of seed pocket separated clearly and must be put into distributer funnel by an assistant operator. The length of gap being varied according to the nature and purpose of the plot. The objectives of this experiment were 1- to design and construct a local self-propelled plot seeder and 2- To compare it with the imported (Wintersteiger plot seeder in cereal breeding programs. Materials and Methods A small-plot seeder was designed and constructed to meet this objective. The unit consists of the following basic components: a toolbar for pulling a set of six blade coulter, an air compressor for lifting and putting down the openers and metering transmission drive wheel, an operators chair and work rack, one belt seed distribution. A cone-celled and rotor seed distributor is used for seed distribution to the openers. The cone system is connected to the gearbox and allows for great flexibility in changing cultivars, crop species, and plot length. This is driven by the separate drive wheel. The cone-celled distributor sows all the seed of the sample in making one complete turn. The

  17. Low crop plant population densities promote pollen-mediated gene flow in spring wheat (Triticum aestivum L.).

    Science.gov (United States)

    Willenborg, Christian J; Brûlé-Babel, Anita L; Van Acker, Rene C

    2009-12-01

    Transgenic wheat is currently being field tested with the intent of eventual commercialization. The development of wheat genotypes with novel traits has raised concerns regarding the presence of volunteer wheat populations and the role they may play in facilitating transgene movement. Here, we report the results of a field experiment that investigated the potential of spring wheat plant population density and crop height to minimize gene flow from a herbicide-resistant (HR) volunteer population to a non-HR crop. Pollen-mediated gene flow (PMGF) between the HR volunteer wheat population and four conventional spring wheat genotypes varying in height was assessed over a range of plant population densities. Natural hybridization events between the two cultivars were detected by phenotypically scoring plants in F(1) populations followed by verification with Mendelian segregation ratios in the F(1:2) families. PMGF was strongly associated with crop yield components, but showed no association with flowering synchrony. Maximum observed PMGF was always less than 0.6%, regardless of crop height and density. The frequency of PMGF in spring wheat decreased exponentially with increasing plant population density, but showed no dependence on either crop genotype or height. However, increasing plant densities beyond the recommended planting rate of 300 cropped wheat plants m(-2) provided no obvious benefit to reducing PMGF. Nevertheless, our results demonstrate a critical plant density of 175-200 cropped wheat plants m(-2) below which PMGF frequencies rise exponentially with decreasing plant density. These results will be useful in the development of mechanistic models and best management practices that collectively facilitate the coexistence of transgenic and nontransgenic wheat crops.

  18. Development of quality assurance and performance testing for the Process Experimental Pilot Plant

    International Nuclear Information System (INIS)

    Dole, L.R.; McDaniel, E.W.; Robinson, S.M.

    1984-08-01

    The Process Experimental Pilot Plant (PREPP) is planned for operation by EG and G Idaho, Inc., to demonstrate a full-scale, cement-based, disposal process for transuranic (TRU) wastes. Procedures need to be developed to determine the quality of the waste product during processing and the durability of the final waste form produced in this facility. This report summarizes basic guidelines for the selection of the waste form composition and process conditions that affect product performance. Physical property tests that may be applicable for quality assurance during processing are also described. Approaches to accelerated performance tests needed to predict the performance of the cement-based waste form are identified, and suggestions are made for the development of processing tests to ensure the quality of the final waste-host product. 29 references, 3 figures, 4 tables

  19. Development of quality assurance and performance testing for the Process Experimental Pilot Plant

    International Nuclear Information System (INIS)

    Dole, L.R.; McDaniel, E.W.; Robinson, S.M.

    1984-06-01

    The Process Experimental Pilot Plant (PREPP) is planned for operation by EG and G Idaho, Inc., to demonstrate a full-scale, cement-based, disposal process for transuranic (TRU) wastes. Procedures need to be developed to determine the quality of the waste product during processing and the durability of the final waste form produced in this facility. This report summarizes basic guidelines for the selection of the waste form composition and process conditions that affect product performance. Physical property tests that may be applicable for quality assurance during processing are also described. Approaches to accelerated performance tests needed to predict the performance of the cement-based waste form are identified, and suggestions are made for the development of processing tests to assure the quality of the final waste-host product. 29 references, 3 figures, 3 tables

  20. Quality Assurance Program Plan for the Waste Isolation Pilot Plant Experimental-Waste Characterization Program

    International Nuclear Information System (INIS)

    1991-01-01

    This Quality Assurance Program Plan (QAPP) identifies the quality of data necessary to meet the specific objectives associated with the Department of Energy (DOE) Waste Isolation Pilot Plant (WIPP) Experimental-Waste Characterization Program (the Program). DOE plans to conduct experiments in the WIPP during a Test Phase of approximately 5 years. These experiments will be conducted to reduce the uncertainties associated with the prediction of several processes (e.g., gas generation) that may influence repository performance. The results of the experiments will be used to assess the ability of the WIPP to meet regulatory requirements for the long-term protection of human health and the environment from the disposal of TRU wastes. 37 refs., 25 figs., 18 tabs

  1. The numerical and experimental study of two passes power plant condenser

    Directory of Open Access Journals (Sweden)

    Rusowicz Artur

    2017-01-01

    Full Text Available The steam condenser is one of the most important element in whole power plant installation. Their proper design and operation makes a significant contribution to the efficiency of electricity production. The purpose of this article is to propose a two-dimensional mathematical model that allows modeling condenser work. In the model, the tube bundle is treated as a porous bed. The analysis has been subjected to a two passes power condenser with a capacity of 50 MW. The mathematical analysis was compared with the results of experimental studies. The average error between the model and the experiment for difference of cooling water temperatures was 5.15% and 11.60% for the first and second pass respectively. This allows to conclude that the proposed model is good enough to optimize future work of the condenser.

  2. Population Status of Commercially Important Medicinal Plants in Dehradun Forest Division, Uttarakhand (India

    Directory of Open Access Journals (Sweden)

    Ninad B. RAUT

    2013-05-01

    Full Text Available The objective of forest management in the tropics, in recent decades, has shifted from timber production to biodiversity conservation and maintenance of life support system. However, past forestry practices have greatly influenced the structure of plant communities, preponderance of foreign invasive species, populations of high value medicinal plants as well as other non-wood forest products. We assessed the abundance and distribution of medicinal plants in managed and undisturbed forests of Dehradun Forest Division (DFD, Uttarakhand (India. A total of 80 transects (each 1 km long were laid in various categories of forest types in DFD. This paper deals with distribution, availability and regeneration status of five commercially important species viz., Justicia adhatoda, Aegle marmelos, Phyllanthus emblica, Terminalia bellirica and Terminalia chebula, across different forest types. The study reveals that open canopy forest patches, Lantana infested patches and Acacia catechu-Dalbergia sissoo (Khair -Shisam woodlands in the eastern part of the DFD have excellent potential for the production and sustainable harvest of Justicia adhatoda. Areas those are less suitable for timber production viz., open hill forests, have greater potential for conservation and development of Aegle marmelos, Phyllanthus emblica and Terminalia bellirica. For the production and management of high value medicinal plants in the DFD these ecological considerations need to be kept in mind.

  3. An experimental technique for the modelling of air flow movements in nuclear plant

    International Nuclear Information System (INIS)

    Ainsworth, R.W.; Hallas, N.J.

    1986-01-01

    This paper describes an experimental technique developed at Harwell to model ventilation flows in plant at 1/5th scale. The technique achieves dynamic similarity not only for forced convection imposed by the plant ventilation system, but also for the interaction between natural convection (from heated objects) and forced convection. The use of a scale model to study flow of fluids is a well established technique, relying upon various criteria, expressed in terms of dimensionless numbers, to achieve dynamic similarity. For forced convective flows, simulation of Reynolds number is sufficient, but to model natural convection and its interaction with forced convection, the Rayleigh, Grashof and Prandtl numbers must be simulated at the same time. This paper describes such a technique, used in experiments on a hypothetical glove box cell to study the interaction between forced and natural convection. The model contained features typically present in a cell, such as a man, motor, stairs, glove box, etc. The aim of the experiment was to study the overall flow patterns, especially around the model man 'working' at the glove box. The cell ventilation was theoretically designed to produce a downward flow over the face of the man working at the glove box. However, the results have shown that the flow velocities produced an upwards flow over the face of the man. The work has indicated the viability of modelling simultaneously the forced and natural convection processes in a cell. It has also demonstrated that simplistic assumptions cannot be made about ventilation flow patterns. (author)

  4. Cyanobacteria as an Experimental Platform for Modifying Bacterial and Plant Photosynthesis

    International Nuclear Information System (INIS)

    Jensen, Poul Erik; Leister, Dario

    2014-01-01

    One of the fascinating characteristics of photosynthesis is its capacity for repair, self-renewal, and energy storage within chemical bonds. Given the evolutionary history of plant photosynthesis and the patchwork nature of many of its components, it is safe to assume that the light reactions of plant photosynthesis can be improved by genetic engineering (Leister, 2012). The evolutionary precursor of chloroplasts was a microorganism whose biochemistry was very similar to that of present-day cyanobacteria. Many cyanobacterial species are easy to manipulate genetically and grow robustly in liquid cultures that can be easily scaled up into photobioreactors. Therefore, cyanobacteria such as Synechocystis sp. PCC 6803 (hereafter “Synechocystis”) have widely been used for decades as model systems to study the principles of photosynthesis (Table 1). Indeed, genetic engineering based on homologous recombination is well-established in Synechocystis. Moreover, new genetic engineering toolkits, including marker-less gene deletion and replacement strategies needing only a single transformation step (Viola et al., 2014) and novel approaches for chromosomal integration and expression of synthetic gene operons (Bentley et al., 2014), allow for large-scale replacement and/or integration of dozens of genes in reasonable time frames. This makes Synechocystis a very attractive basis for the experimental modification of important processes like photosynthesis, and it also suggests innovative ways of improving modules of related eukaryotic pathways, among them the combination of cyanobacterial and eukaryotic elements using the tools of synthetic biology.

  5. Controlling system for an experimental demonstration plant for energy conversion using PEMFCs

    International Nuclear Information System (INIS)

    Culcer, Mihail; Iliescu, Mariana; Stefanescu, Ioan; Raceanu, Mircea; Enache, Adrian; Patularu, Laurentiu

    2006-01-01

    Full text: In the last decades of the previous century, due to global environmental problems, energy security and supply issues, many studies were conducted to investigate the uses for hydrogen energy and facilitate its penetration as an energy carrier. Subsequently, many industries worldwide began developing and producing hydrogen, hydrogen-powered vehicles, hydrogen fuel cells, and other hydrogen-based technologies. In view of the substantial long-term public and private benefits arising from hydrogen and fuel cells, the European Union and national governments throughout Europe, including the Romanian one, are working towards developing a consistent policy framework preparing the transition to a hydrogen based economy. ICIT Rm Valcea developed a research program on energy conversion using fuel cells, a project supported by the Romanian Ministry of Education and Research within the National R and D Program. An experimental demonstration pilot plant of energy conversion using PEMFCs and hydrogen producing via steam methane reforming (SMR) was achieved in order to investigate the development of small-scale SMR technologies and to allow testing and developing of specific components. The paper deals with the dedicated controlling system that provides automated data acquisition, manual or 'on line' operational control, gas management, humidification, temperature and flow controls of the pilot plant. (authors)

  6. Cyanobacteria as an Experimental Platform for Modifying Bacterial and Plant Photosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Poul Erik [Copenhagen Plant Science Center (CPSC), Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen (Denmark); Leister, Dario, E-mail: leister@lmu.de [Copenhagen Plant Science Center (CPSC), Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen (Denmark); Plant Molecular Biology (Botany), Department of Biology I, Ludwig-Maximilians-University Munich, Munich (Germany)

    2014-04-21

    One of the fascinating characteristics of photosynthesis is its capacity for repair, self-renewal, and energy storage within chemical bonds. Given the evolutionary history of plant photosynthesis and the patchwork nature of many of its components, it is safe to assume that the light reactions of plant photosynthesis can be improved by genetic engineering (Leister, 2012). The evolutionary precursor of chloroplasts was a microorganism whose biochemistry was very similar to that of present-day cyanobacteria. Many cyanobacterial species are easy to manipulate genetically and grow robustly in liquid cultures that can be easily scaled up into photobioreactors. Therefore, cyanobacteria such as Synechocystis sp. PCC 6803 (hereafter “Synechocystis”) have widely been used for decades as model systems to study the principles of photosynthesis (Table 1). Indeed, genetic engineering based on homologous recombination is well-established in Synechocystis. Moreover, new genetic engineering toolkits, including marker-less gene deletion and replacement strategies needing only a single transformation step (Viola et al., 2014) and novel approaches for chromosomal integration and expression of synthetic gene operons (Bentley et al., 2014), allow for large-scale replacement and/or integration of dozens of genes in reasonable time frames. This makes Synechocystis a very attractive basis for the experimental modification of important processes like photosynthesis, and it also suggests innovative ways of improving modules of related eukaryotic pathways, among them the combination of cyanobacterial and eukaryotic elements using the tools of synthetic biology.

  7. Neutron dosimetry in EDF experimental surveillance programme for VVER-440 nuclear power plants

    International Nuclear Information System (INIS)

    Brumovsky, M.; Erben, O.; Novosad, P.; Zerola, L.; Hogel, J.; Trollat, C.

    2001-01-01

    Fourteen chains containing experimental surveillance material specimens of the VVER 440/213 nuclear power reactor pressure vessels were irradiated in the surveillance channels of the Nuclear Power Plant Dukovany in the Czech Republic. The irradiation periods were one, two or three cycles. The chains contained different number and types of containers, the omitted ones were replaced by chain elements. All of the containers were instrumented with wire neutron fluence detectors, some of the containers in the chain had spectrometric sets of neutron fluence monitors. For the absolute fluence values evaluation it was taken into account time history of the reactor power and local changes of the neutron flux along the reactor core height, correction factors due to the orientation of monitors with respect to the reactor core centre. Unfolding programs SAND-II or BASA-CF were used. The relative axial fluence distribution was obtained from the O-wire measurements. Neutron fluence values above 0.5 MeV energy and above 1.0 MeV energy in the container axis on the axial positions of the sample centres and fluence values in the geometric centre of the samples was calculated making use the exponential attenuation model of the incident neutron beam. Received fast neutron fluence values can be used as reference values to all VVER-440 type 213 nuclear power plant reactors. (author)

  8. Radiation protection of population under normal operation conditions of nuclear power plants

    International Nuclear Information System (INIS)

    Kunz, Eh.; Shvets, I.

    1976-01-01

    Evolution of shielding is defined in short; approaches suggested for applying in radiation protection or being used are evaluated and classified. Modern views analysis of a risk of biological irradiation consequences in public approaches to health protection in connection with the technical progress side by side with provision of separate persons protection requires attentin to the nuclear power plants protection optimization. Protection optimization suggests the analysis of separate components of technology and protection systems, used materials and constructive solutions, maintenance rules and operating load with respect to environmental discharge of radioactive products. It is expedient to carry out similtaneously the similar analysis with respect to the nuclear power plant personnel irradiation, as separate measures can affect both personnel and population irradiation [ru

  9. Influence of ambient and enhanced ultraviolet-B radiation on the plant growth and physiological properties in two contrasting populations of Hippophae rhamnoides

    International Nuclear Information System (INIS)

    Yang, Y.; Yao, Y.; He, H.

    2008-01-01

    Two contrasting sea buckthorn (Hippophae rhamnoides L.) populations from low and high altitude regions were employed to investigate the effects of prevailing and enhanced ultraviolet-B (UV-B) radiation on plant growth and physiological properties under a UVB-enhanced/exclusion system. The experimental design included three UV-B regimes, including excluded (-UVB), near-ambient (NA) and enhanced UV-B (+UVB) radiation. Compared with the control (-UVB), NA caused the formation of smaller but thicker plant leaves in both sea buckthorn populations, paralleled with significant increments of carotenoids and UV-absorbing compounds as well as improved water economy. NA also induced more biomass partition from shoot to root, but CO2 assimilation rate (A), photosynthetic area and biomass accumulation were unaffected. The low-altitude population seemed sensitive to +uvB, as indicated by the decreases in total biomass, A and ascorbic acid content (Asa, an antioxidant) compared with NA. However, little +UVB effect occurred on the high-altitude population, and we suggest that the higher tolerance of this population could be associated with its specific morphological and physiological characteristics, such as small but thick leaves and high-level of Asa content, as well as its greater physiological modification in response to NA, e.g., increases in protective compounds (carotenoids and UV-absorbing compounds) and improvement in water economy, in comparison to the low-altitude population, which form an effective adaptation strategy to enhanced UV-B stress

  10. Distinguishing plant population and variety with UAV-derived vegetation indices

    Science.gov (United States)

    Oakes, Joseph; Balota, Maria

    2017-05-01

    Variety selection and seeding rate are two important choice that a peanut grower must make. High yielding varieties can increase profit with no additional input costs, while seeding rate often determines input cost a grower will incur from seed costs. The overall purpose of this study was to examine the effect that seeding rate has on different peanut varieties. With the advent of new UAV technology, we now have the possibility to use indices collected with the UAV to measure emergence, seeding rate, growth rate, and perhaps make yield predictions. This information could enable growers to make management decisions early in the season based on low plant populations due to poor emergence, and could be a useful tool for growers to use to estimate plant population and growth rate in order to help achieve desired crop stands. Red-Green-Blue (RGB) and near-infrared (NIR) images were collected from a UAV platform starting two weeks after planting and continued weekly for the next six weeks. Ground NDVI was also collected each time aerial images were collected. Vegetation indices were derived from both the RGB and NIR images. Greener area (GGA- the proportion of green pixels with a hue angle from 80° to 120°) and a* (the average red/green color of the image) were derived from the RGB images while Normalized Differential Vegetative Index (NDVI) was derived from NIR images. Aerial indices were successful in distinguishing seeding rates and determining emergence during the first few weeks after planting, but not later in the season. Meanwhile, these aerial indices are not an adequate predictor of yield in peanut at this point.

  11. Mortality gradients within and among dominant plant populations as barometers of ecosystem change during extreme drought.

    Science.gov (United States)

    Gitlin, Alicyn R; Sthultz, Christopher M; Bowker, Matthew A; Stumpf, Stacy; Paxton, Kristina L; Kennedy, Karla; Muñoz, Axhel; Bailey, Joseph K; Whitham, Thomas G

    2006-10-01

    Understanding patterns of plant population mortality during extreme weather events is important to conservation planners because the frequency of such events is expected to increase, creating the need to integrate climatic uncertainty into management. Dominant plants provide habitat and ecosystem structure, so changes in their distribution can be expected to have cascading effects on entire communities. Observing areas that respond quickly to climate fluctuations provides foresight into future ecological changes and will help prioritize conservation efforts. We investigated patterns of mortality in six dominant plant species during a drought in the southwestern United States. We quantified population mortality for each species across its regional distribution and tested hypotheses to identify ecological stress gradients for each species. Our results revealed three major patterns: (1) dominant species from diverse habitat types (i.e., riparian, chaparral, and low- to high-elevation forests) exhibited significant mortality, indicating that the effects of drought were widespread; (2) average mortality differed among dominant species (one-seed juniper[Juniperus monosperma (Engelm.) Sarg.] 3.3%; manzanita[Arctostaphylos pungens Kunth], 14.6%; quaking aspen[Populus tremuloides Michx.], 15.4%; ponderosa pine[Pinus ponderosa P. & C. Lawson], 15.9%; Fremont cottonwood[Populus fremontii S. Wats.], 20.7%; and pinyon pine[Pinus edulis Engelm.], 41.4%); (3) all dominant species showed localized patterns of very high mortality (24-100%) consistent with water stress gradients. Land managers should plan for climatic uncertainty by promoting tree recruitment in rare habitat types, alleviating unnatural levels of competition on dominant plants, and conserving sites across water stress gradients. High-stress sites, such as those we examined, have conservation value as barometers of change and because they may harbor genotypes that are adapted to climatic extremes.

  12. Estimating population exposure to power plant emissions using CALPUFF: a case study in Beijing, China

    Energy Technology Data Exchange (ETDEWEB)

    Ying Zhou; Levy, J.I. [Harvard School of Public Health, Boston, MA (United States); Hammitt, J.K.; Evans, J.S. [Harvard Center for Risk Analysis, Boston, MA (United States)

    2003-02-01

    Epidemiological studies have shown a significant association between ambient particulate matter (PM) exposures and increased mortality and morbidity risk. Power plants are significant emitters of precursor gases of fine particulate matter. To evaluate the public health risk posed by power plants, it is necessary to evaluate population exposure to different pollutants. The concept of intake fraction (the fraction of a pollutant emitted that is eventually inhaled or ingested by a population) has been proposed to provide a simple summary measure of the relationship between emissions and exposure. Currently available intake fraction estimates from developing countries used models that look only at the near field impacts, which may not capture the full impact of a pollution source. This case study demonstrated how the intake fraction of power plant emissions in China can be calculated using a detailed long-range atmospheric dispersion model-CALPUFF. We found that the intake fraction of primary fine particles is roughly on the order of 10{sup -5}, while the intake fractions of sulfur dioxide, sulfate and nitrate are on the order of 10{sup -6}. These estimates are an order of magnitude higher than the US estimates. We also tested how sensitive the results were to key assumptions within the model. The size distribution of primary particles has a large impact on the intake fraction for primary particles while the background ammonia concentration is an important factor influencing the intake fraction of nitrate. The background ozone concentration has a moderate impact on the intake fraction of sulfate and nitrate. Our analysis shows that this approach is applicable to a developing country and it provides reasonable population exposure estimates. (author)

  13. Geographic population structure in an outcrossing plant invasion after centuries of cultivation and recent founding events.

    Science.gov (United States)

    Gaskin, John F; Schwarzländer, Mark; Gibson, Robert D; Simpson, Heather; Marshall, Diane L; Gerber, Esther; Hinz, Hariet

    2018-04-01

    Population structure and genetic diversity of invasions are the result of evolutionary processes such as natural selection, drift and founding events. Some invasions are also molded by specific human activities such as selection for cultivars and intentional introduction of desired phenotypes, which can lead to low genetic diversity in the resulting invasion. We investigated the population structure, diversity and origins of a species with both accidental and intentional introduction histories, as well as long-term selection as a cultivar. Dyer's woad ( Isatis tinctoria ; Brassicaceae) has been used as a dye source for at least eight centuries in Eurasia, was introduced to eastern USA in the 1600s, and is now considered invasive in the western USA. Our analyses of amplified fragment length polymorphisms (AFLPs) from 645 plants from the USA and Eurasia did not find significantly lower gene diversity ( H j ) in the invaded compared to the native range. This suggests that even though the species was under cultivation for many centuries, human selection of plants may not have had a strong influence on diversity in the invasion. We did find significantly lower genetic differentiation ( F st ) in the invasive range but our results still suggested that there are two distinct invasions in the western USA. Our data suggest that these invasions most likely originated from Switzerland, Ukraine and Germany, which correlates with initial biological control agent survey findings. Genetic information on population structure, diversity and origins assists in efforts to control invasive species, and continued combination of ecological and molecular analyses will help bring us closer to sustainable management of plant invasions.

  14. Mites fluctuation population on peach tree (Prunus persica (L. Batsch and in associated plants

    Directory of Open Access Journals (Sweden)

    Carla Rosana Eichelberger

    2011-09-01

    Full Text Available Despite the importance of peach (Prunus persica (L. Batsch in Rio Grande do Sul, little is known about mites fluctuation population considered important to this crop. The objective of this study was to know the population diversity and fluctuation of mite species associated with Premier and Eldorado varieties in Roca Sales and Venâncio Aires counties, Rio Grande do Sul. The study was conducted from July 2008 to June 2009 when 15 plants were randomly chosen in each area. The plants were divided in quadrants and from each one a branch was chosen from which three leaves were removed: one collected in the apical region, another in the medium and the other in the basal region, totalizing 180 leaves/area. Five of the most abundant associated plants were collected monthly in enough amounts for the screening under the stereoscopic microscope during an hour. A total of 1,124 mites were found belonging to 14 families and 28 species. Tetranychus ludeni Zacher, 1913, Panonychus ulmi (Koch, 1836 and Mononychellus planki (McGregor, 1950 were the most abundant phytophagous mites, whereas Typhlodromalus aripo Deleon, 1967 and Phytoseiulus macropilis (Banks, 1904 the most common predatory mites. The period of one hour under stereoscopic microscope was enough to get a representative sample. In both places evaluated the ecologic indices were low, but little higherin Premier (H' 0.56; EqJ: 0.43 when compared to Eldorado (H' 0.53; EqJ 0.40. In Premier constant species were not observed and accessory only Brevipalpus phoenicis (Geijskes, 1939, T. ludeni and T. aripo. Higher abundance was observed in December and January and bigger amount in April. Already in Eldorado, T. ludeni and P. ulmi were constants. Greater abundance was observed in November and December, whereas grater richness in December and January. In both orchards were not found mites in buds. Tetranychus ludeni is the most abundant phytophagous mites with outbreak population in November, December and

  15. Modifying rainfall patterns in a Mediterranean shrubland: system design, plant responses, and experimental burning.

    Science.gov (United States)

    Parra, Antonio; Ramírez, David A; Resco, Víctor; Velasco, Ángel; Moreno, José M

    2012-11-01

    Global warming is projected to increase the frequency and intensity of droughts in the Mediterranean region, as well as the occurrence of large fires. Understanding the interactions between drought, fire and plant responses is therefore important. In this study, we present an experiment in which rainfall patterns were modified to simulate various levels of drought in a Mediterranean shrubland of central Spain dominated by Cistus ladanifer, Erica arborea and Phillyrea angustifolia. A system composed of automatic rainout shelters with an irrigation facility was used. It was designed to be applied in vegetation 2 m tall, treat relatively large areas (36 m2), and be quickly dismantled to perform experimental burning and reassembled back again. Twenty plots were subjected to four rainfall treatments from early spring: natural rainfall, long-term average rainfall (2 months drought), moderate drought (25% reduction from long-term rainfall, 5 months drought) and severe drought (45% reduction, 7 months drought). The plots were burned in late summer, without interfering with rainfall manipulations. Results indicated that rainfall manipulations caused differences in soil moisture among treatments, leading to reduced water availability and growth of C. ladanifer and E. arborea in the drought treatments. However, P. angustifolia was not affected by the manipulations. Rainout shelters had a negligible impact on plot microenvironment. Experimental burns were of high fire intensity, without differences among treatments. Our system provides a tool to study the combined effects of drought and fire on vegetation, which is important to assess the threats posed by climate change in Mediterranean environments.

  16. Selection and adaptation in irradiated plant and animal populations: a review

    International Nuclear Information System (INIS)

    Hart, D.R.

    1981-03-01

    Available literature on the effects of ionizing radiation on mutation rates, variability and adaptive responses to selection in exposed plant and animal populations is reviewed. Accumulated variability, and hence potential selection differentials, may be increased by many times due to induced mutation. The radiation dose that maximizes induced mutation varies greatly among species, strains and genetic systems. Induced variability tends to enhance the respose to selection, but this effect may be delayed or prevented by an initial reduction in the heritability of induced variation. Significantly, the detrimental effects of harmful mutations in irradiated populations may exceed the beneficial effects of selection for adaptive characteristics. Selection for radioresistance may occur at lethal or sub-lethal radiation doses but dose relationships are highly variable. (author)

  17. Effect of Planting Patterns' and Plant Population on Some of Morphological Traits, Harvest Index and Conservable Grain Yield of Sweet Corn

    Directory of Open Access Journals (Sweden)

    M. Nasrolah Alhossini

    2012-04-01

    Full Text Available Sweet corn is one of the most important crops in Iran and due to its short period of growth, it has been an important position after wheat and barley in khorasane Razavi Province. In this study two methods of planting (one raised bed and furrow planting and 3 plant densities (65000, 75000 and 85000 plant/ha was evaluated on some of Morphological Traits, harvest index and conservable grain yield of sweet Corn(Chase and KSC403su Varieties in Torbat-e-Heidarie in saline (4.060ds/m condition on 2009. The experimental design was factorial based on RCBC with 4 replications. The result of ANOVA showed significant differences between Anthesis silking interval (ASI, tassel length, plant height, ear height, stem diameter, harvest index, and conservable grain yield of sweet corn varieties that effected by planting methods. the highest harvest index was belonged to Chase in 75000 Plant/ha on one raised bed planting method with 31.75% and the lowest mean was belonged to KSC403su in 85000 Plant/ha on furrow planting method with 14.93%. In addition the highest grain yield was belonged to chase variety at 75000 plant/ha and furrow planting method with 11.912 ton/ha, while the lowest grain yield was belonged to KSC403su variety at 85000 plant/ha and raised bed planting (3.610 ton/ha. The Chase variety was better than KSC403su Due to its canopy and photo period is shorter than KSC403su. The superiority of Chase variety can be related to better distribution of leaves, highest harvest index, conservable grain yield and plant arrangement in the row.

  18. Definition, analysis and experimental investigation of operation modes in hydrogen-renewable-based power plants incorporating hybrid energy storage

    International Nuclear Information System (INIS)

    Valverde, L.; Pino, F.J.; Guerra, J.; Rosa, F.

    2016-01-01

    Highlights: • A conceptual analysis of operation modes in energy storage plants is presented. • Key Performance Indicators to select operation modes are provided. • The approach has been applied to a laboratory hybrid power plant. • The methodology provides guidance for the operation of hybrid power plants. - Abstract: This paper is concerned with Operating Modes in hybrid renewable energy-based power plants with hydrogen as the intermediate energy storage medium. Six operation modes are defined according to plant topology and the possibility of operating electrolyzer and fuel cell at steady-power or partial load. A methodology for the evaluation of plant performance is presented throughout this paper. The approach includes a set of simulations over a fully validated model, which are run in order to compare the proposed operation modes in various weather conditions. Conclusions are drawn from the simulation stage using a set of Key Performance Indicators defined in this paper. This analysis yields the conclusion that certain modes are more appropriate from technical and practical standpoints when they are implemented in a real plant. From the results of the simulation assessment, selected operating modes are applied to an experimental hydrogen-based pilot plant to illustrate and validate the performance of the proposed operation modes. Experimental results confirmed the simulation study, pointing out the advantages and disadvantages of each operation mode in terms of performance and equipment durability.

  19. Experimental results and thermodynamic analysis of a natural gas small scale cogeneration plant for power and refrigeration purposes

    International Nuclear Information System (INIS)

    Bazzo, Edson; Nacif de Carvalho, Alvaro; Matelli, José Alexandre

    2013-01-01

    In this work, experimental results are reported for a small scale cogeneration plant for power and refrigeration purposes. The plant includes a natural gas microturbine and an ammonia/water absorption chiller fired by steam. The system was tested under different turbine loads, steam pressures and chiller outlet temperatures. An evaluation based on the 1st and 2nd Laws of Thermodynamics was also performed. For the ambient temperature around 24 °C and microturbine at full load, the plant is able to provide 19 kW of saturated steam at 5.3 bar (161 °C), corresponding to 9.2 kW of refrigeration at −5 °C (COP = 0.44). From a 2nd law point-of-view, it was found that there is an optimal chiller outlet temperature that maximizes the chiller exergetic efficiency. As expected, the microturbine presented the highest irreversibilities, followed by the absorption chiller and the HRSG. In order to reduce the plant exergy destruction, it is recommended a new design for the HRSG and a new insulation for the exhaust pipe. -- Highlights: • A small scale cogeneration plant for power and refrigeration is proposed and analyzed. • The plant is based on a microturbine and a modified absorption chiller. • The plant is analysed based on 1st and 2nd laws of thermodynamics. • Experimental results are found for different power and refrigeration conditions. • The plant proved to be technically feasible

  20. Strong Genetic Differentiation of Submerged Plant Populations across Mountain Ranges: Evidence from Potamogeton pectinatus in Iran.

    Science.gov (United States)

    Abbasi, Shabnam; Afsharzadeh, Saeed; Saeidi, Hojjatollah; Triest, Ludwig

    2016-01-01

    Biogeographic barriers for freshwater biota can be effective at various spatial scales. At the largest spatial scale, freshwater organisms can become genetically isolated by their high mountain ranges, vast deserts, and inability to cross oceans. Isolation by distance of aquatic plants is expected to be stronger across than alongside mountain ridges whereas the heterogeneity of habitats among populations and temporary droughts may influence connectivity and hamper dispersal. Suitable aquatic plant habitats became reduced, even for the widespread submerged Potamogeton pectinatus L. (also named Stuckenia pectinata) giving structure to various aquatic habitats. We compared the level of genetic diversity in a heterogeneous series of aquatic habitats across Iran and tested their differentiation over distances and across mountain ranges (Alborz and Zagros) and desert zones (Kavir), with values obtained from temperate region populations. The diversity of aquatic ecosystems across and along large geographic barriers provided a unique ecological situation within Iran. P. pectinatus were considered from thirty-six sites across Iran at direct flight distances ranging from 20 to 1,200 km. Nine microsatellite loci revealed a very high number of alleles over all sites. A PCoA, NJT clustering and STRUCTURE analysis revealed a separate grouping of individuals of southeastern Iranian sites and was confirmed by their different nuclear ITS and cpDNA haplotypes thereby indicating an evolutionary significant unit (ESU). At the level of populations, a positive correlation between allelic differentiation Dest with geographic distance was found. Individual-based STRUCTURE analysis over 36 sites showed 7 genetic clusters. FST and RST values for ten populations reached 0.343 and 0.521, respectively thereby indicating that allele length differences are more important and contain evolutionary information. Overall, higher levels of diversity and a stronger differentiation was revealed among

  1. Geographic structuring and transgenerational maternal effects shape germination in native, but not introduced, populations of a widespread plant invader.

    Science.gov (United States)

    Alba, Christina; Moravcová, Lenka; Pyšek, Petr

    2016-05-01

    Germination is critical in determining species distributions and invasion dynamics. However, is it unclear how often invasive populations evolve germination characteristics different from native populations, because few studies have isolated genetic variation by using seed from garden-grown plants. Additionally, while herbivore-induced transgenerational effects are common, it is unknown whether maternal herbivory differentially shapes germination in native and introduced offspring. We explored germination in native and introduced populations of the North American invader Verbascum thapsus using seed from garden-grown maternal plants, half of which were protected from herbivores. To elucidate (1) germination niche breadth and (2) whether germination conditions affected expression of genetic structuring among populations, we germinated seed under four ecologically relevant temperature regimes. Native populations had a wide germination niche breadth, germinating as well as or better than introduced populations. At cooler temperatures, native populations exhibited a genetically based environmental cline indicative of local adaptation, with populations from warmer locales germinating better than populations from cooler locales. However, this cline was obscured when maternal plants were attacked by herbivores, revealing that local stressors can override the expression of geographic structuring. Introduced populations did not exhibit clinal variation, suggesting its disruption during the introduction process. Native and introduced populations have evolved genetic differences in germination. The result of this difference manifests in a wider germination niche breadth in natives, suggesting that the invasive behavior of V. thapsus in North America is attributable to other factors. © 2016 Botanical Society of America.

  2. Population dose commitments due to radioactive releases from nuclear power plant sites in 1982. Volume 4

    International Nuclear Information System (INIS)

    Baker, D.A.; Peloquin, R.A.

    1986-06-01

    Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1982. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 51 sites. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ. Also included for each site is a histogram showing the fraction of the total population within 2 to 80 km around each site receiving various average dose commitments from the airborne pathways. The total dose commitments from both liquid and airborne pathways ranged from a high of 30 person-rem to a low of 0.007 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 3 person-rem. The total population dose for all sites was estimated at 130 person-rem for the 100 million people considered at risk. The average individual dose commitment from all pathways on a site basis ranged from a low of 6 x 10 -7 mrem to a high of 0.06 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites

  3. About a dynamic model of interaction of insect population with food plant

    Directory of Open Access Journals (Sweden)

    L.V. Nedorezov

    2011-12-01

    Full Text Available In present paper there is the consideration of mathematical model of food plant (resource - consumer (insect population - pathogen system dynamics which is constructed as a system of ordinary differential equations. The dynamic regimes of model are analyzed and, in particular, with the help of numerical methods it is shown that trigger regimes (regimes with two stable attractors can be realized in model under very simple assumptions about ecological and intra-population processes functioning. Within the framework of model it was assumed that the rate of food flow into the system is constant and functioning of intra-population selfregulative mechanisms can be described by Verhulst model. As it was found, trigger regimes are different with respect to their properties: in particular, in model the trigger regimes with one of stable stationary points on the coordinate plane can be realized (it corresponds to the situation when sick individuals in population are absent and their appearance in small volume leads to their asymptotic elimination; also the regimes with several nonzero stationary states and stable periodic fluctuations were found.

  4. Population dose commitments due to radioactive releases from nuclear power plant sites in 1986

    International Nuclear Information System (INIS)

    Baker, D.A.

    1989-10-01

    Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1986. Fifty-year dose commitments for a one-year exposure from both liquid and atmospheric releases were calculated for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 66 reactor sites. This report tabulates the results of these calculations, showing the dose commitments for both water and airborne pathways for each age group and organ. Also included for each of the sites is a histogram showing the fraction of the total population within 2 to 80 km around each site receiving various average dose commitments from the airborne pathways. The total dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 31 person-rem to a low of 0.0007 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 1.7 person-rem. The total population dose for all sites was estimated at 110 person-rem for the 140 million people considered at risk. The site average individual dose commitment from all pathways ranged from a low of 2 x 10 -6 mrem to a high of 0.02 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites. 12 refs

  5. Population dose commitments due to radioactive releases from nuclear power plant sites in 1984

    International Nuclear Information System (INIS)

    Baker, D.A.

    1988-01-01

    Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1984. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 56 sites. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ. Also included for each of the sites is a histogram showing the fraction of the total population within 2 to 80 km around each site receiving various average dose commitments from the airborne pathways. The total dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 110 person-rem to a low of 0.002 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 5 person-rem. The total population dose for all sites was estimated at 280 person-rem for the 100 million people considered at risk. The site average individual dose commitment from all pathways ranged from a low of 6 x 10 -6 mrem to a high of 0.04 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites

  6. Population dose commitments due to radioactive releases from nuclear power plant sites in 1983

    International Nuclear Information System (INIS)

    Baker, D.A.; Peloquin, R.A.

    1987-04-01

    Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1983. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 52 sites. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ. Also included for each of the sites is a histogram showing the fraction of the total population within 2 to 80 km around each site receiving various average dose commitments from the airborne pathways. The total dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 45 person-rem to a low of 0.002 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 3 person-rem. The total population dose for all sites was estimated at 170 person-rem for the 100 million people considered at risk

  7. Population dose commitments due to radioactive releases from nuclear power plant sites in 1985

    International Nuclear Information System (INIS)

    Baker, D.A.

    1988-08-01

    Population radiation dose commitments have been estimated from reported radionuclide releases from commericial power reactors operating during 1985. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 61 sites. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ. Also included for each of the sites is a histogram showing the fraction of the total population within 2 to 80 km around each site receiving various average dose commitments from the airborne pathways. The total dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 73 person-rem to a low of 0.011 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 3 person-rem. The total population dose for all sites was estimated at 200 person-rem for the 110 million people considered at risk. The site average individual dose commitment from all pathways ranged from a low of 5 /times/ 10/sup /minus/6/ mrem to a high of 0.02 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites

  8. Drought tolerance in wild plant populations: the case of common beans (Phaseolus vulgaris L..

    Directory of Open Access Journals (Sweden)

    Andrés J Cortés

    Full Text Available Reliable estimations of drought tolerance in wild plant populations have proved to be challenging and more accessible alternatives are desirable. With that in mind, an ecological diversity study was conducted based on the geographical origin of 104 wild common bean accessions to estimate drought tolerance in their natural habitats. Our wild population sample covered a range of mesic to very dry habitats from Mexico to Argentina. Two potential evapotranspiration models that considered the effects of temperature and radiation were coupled with the precipitation regimes of the last fifty years for each collection site based on geographical information system analysis. We found that wild accessions were distributed among different precipitation regimes following a latitudinal gradient and that habitat ecological diversity of the collection sites was associated with natural sub-populations. We also detected a broader geographic distribution of wild beans across ecologies compared to cultivated common beans in a reference collection of 297 cultivars. Habitat drought stress index based on the Thornthwaite potential evapotranspiration model was equivalent to the Hamon estimator. Both ecological drought stress indexes would be useful together with population structure for the genealogical analysis of gene families in common bean, for genome-wide genetic-environmental associations, and for postulating the evolutionary history and diversification processes that have occurred for the species. Finally, we propose that wild common bean should be taken into account to exploit variation for drought tolerance in cultivated common bean which is generally considered susceptible as a crop to drought stress.

  9. Investigations concerning the evaluation of discrepancies between calculated and experimentally provable efficiency of UV-plants for disinfection of water

    International Nuclear Information System (INIS)

    Leuker, G.; Hingst, V.

    1992-01-01

    Using three UV-plants of different technical designs for water disinfection, we studied the conformity between experimental germ reduction using standard test organisms and calculated UV-doses under various water flow conditions. Taking into consideration the style of construction of the UV-plants, the irradiation area and the layer thickness were used as constant parameters for dose calculations. This was also employed for the irradiation intensity, since the experiments were performed for a relatively short period compared of the life span of the UV-irradiators. Both exposure time and water transmission were employed as variable parameters in the dose calculations and experimental procedures respectively. The calculated UV-dose and experimentally obtained germ reduction values were comparatively the same for two of the three UV-plants studied. However, no correlation was observed between the reduction of E. coli and the corresponding calculated UV-dose values. Therefore, the calculated UV-dose values for any given UV-plant should be considered to be relative and by no means absolute values. We are of the opinion that within a certain range of water flow rate and transmission, antimicrobial effectiveness of different UV-plants should be demonstrated independent of dose values, technical and other construction characteristics. The applicability of the UV-plants studied is discussed [de

  10. Volatile Constituents of Different Plant Parts and Populations of Malabaila aurea Boiss. from Montenegro

    Directory of Open Access Journals (Sweden)

    Ivan Vučković

    2014-03-01

    Full Text Available The volatile constituents of different plant parts and populations of Malabaila aurea Boiss. from Montenegro were obtained by simultaneous distillation-extraction and analyzed by GC-FID and GC-MS. A total of 12 samples were examined and 45 compounds were identified. The volatile content of different M. aurea populations was very similar, while the volatile fractions obtained from different plant parts showed significant qualitative and quantitative differences. The most abundant compounds found in stems & leaves were apiole (51.0-56.3%, myristicin (16.3-25.4%, and falcarinol (4.1-10.7%. The roots showed the same major components, but with different relative abundances: 30.9-49.1% of apiole, 12.9-34.7% of falcarinol, and 9.9-31.1% of myristicin. The volatile constituents of fruits & flowers were remarkably different, containing up to 71.2-80.5% octyl butyrate, 11.4-18.0% octanol, and 2.7-6.8% octyl hexanoate. The results were discussed as possible indication of relatedness of Malabaila aurea and Pastinacasativa (parsnip .

  11. ROLE OF PLANTS FOUND IN NORTH EAST INDIA AND BANGLADESH IN CONTROLLING POPULATION GROWTH

    Directory of Open Access Journals (Sweden)

    Jhimly Das

    2014-08-01

    Full Text Available Being part of the Indian subcontinent both the North Eastern region of India and the Bangladesh share a long common cultural, economic and political history. One of the most critical problems of developing countries like India as well as Bangladesh is their enormous increase in human population. Contraceptive Prevalence Rate (CPR of India is 48.3 and that of Bangladesh is 53.8. As the large majority of population of both the countries belong to rural area, the family planning programmes have largely remained unsuccessful because of many factors including lack of availability of contraceptive drugs in rural markets, lack of accessibility of rural people to medical personnel as well as the lack of acceptability of synthetic drugs due to various socio-cultural and religious perceptions prevailing among many ethnic communities. These contributed to a growing interest among researchers in developing contraceptives of natural origin and at present natural herbal contraception have become one of the major focuses of modern contraceptive research. Since time immemorial herbal drugs are being practiced by various rural communities and ethnic tribes in North East India as well as in Bangladesh, and hence the acceptability of herbal contraceptives is expected to be much higher among rural folk. In different parts of North East India and Bangladesh, ethnic communities are using plant based medicinal products till today. This study aims at highlighting the contraceptive property of some plants found in North-Eastern India as well as in Bangladesh.

  12. Pollutants emitted by a cement plant: health risks for the population living in the neighborhood

    International Nuclear Information System (INIS)

    Schuhmacher, Marta; Domingo, J.L.; Garreta, Josepa

    2004-01-01

    The aim of this study was to investigate the health risks due to combustor emissions in the manufacturing of Portland cement for the population living in the neighborhood of a cement kiln in Catalonia, Spain. Pollutants emitted to the atmosphere in the course of cement production were modeled. The ISC3-ST model was applied to estimate air dispersion of the contaminants emitted by the cement plant. Air concentrations of NO 2 , SO 2 , PM 10 , metals, and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), as well as the potential exposure in the vicinity of the facility, were assessed via models based on US EPA guidance documents. PCDD/F and metal concentrations were also modeled for soil and vegetation. Based on these concentrations, the levels of human exposure were calculated. Individual cancer and noncancer risks for the emissions of the cement kiln were assessed. Health effects due to NO 2 , SO 2 , and PM 10 emissions were also evaluated. Risk assessment was performed as a deterministic analysis. The main individual risk in the population was evaluated in a central-tendency and a high-end approach. The results show that the incremental individual risk due to emissions of the cement plant is very low not only with regard to health effects, but also in relation to toxicological and cancer risks produced by pollutants such as metals and PCDD/Fs emitted by the cement kiln

  13. Selfing for the design of genomic selection experiments in biparental plant populations.

    Science.gov (United States)

    McClosky, Benjamin; LaCombe, Jason; Tanksley, Steven D

    2013-11-01

    Self-fertilization (selfing) is commonly used for population development in plant breeding, and it is well established that selfing increases genetic variance between lines, thus increasing response to phenotypic selection. Furthermore, numerous studies have explored how selfing can be deployed to maximal benefit in the context of traditional plant breeding programs (Cornish in Heredity 65:201-211,1990a, Heredity 65:213-220,1990b; Liu et al. in Theor Appl Genet 109:370-376, 2004; Pooni and Jinks in Heredity 54:255-260, 1985). However, the impact of selfing on response to genomic selection has not been explored. In the current study we examined how selfing impacts the two key aspects of genomic selection-GEBV prediction (training) and selection response. We reach the following conclusions: (1) On average, selfing increases genomic selection gains by more than 70 %. (2) The gains in genomic selection response attributable to selfing hold over a wide range population sizes (100-500), heritabilities (0.2-0.8), and selection intensities (0.01-0.1). However, the benefits of selfing are dramatically reduced as the number of QTLs drops below 20. (3) The major cause of the improved response to genomic selection with selfing is through an increase in the occurrence of superior genotypes and not through improved GEBV predictions. While performance of the training population improves with selfing (especially with low heritability and small population sizes), the magnitude of these improvements is relatively small compared with improvements observed in the selection population. To illustrate the value of these insights, we propose a practical genomic selection scheme that substantially shortens the number of generations required to fully capture the benefits of selfing. Specifically, we provide simulation evidence that indicates the proposed scheme matches or exceeds the selection gains observed in advanced populations (i.e. F 8 and doubled haploid) across a broad range of

  14. Influence of Plant Population and Nitrogen-Fertilizer at Various Levels on Growth and Growth Efficiency of Maize

    Directory of Open Access Journals (Sweden)

    M. I. Tajul

    2013-01-01

    Full Text Available Field experiments were conducted to evaluate plant population and N-fertilizer effects on yield and yield components of maize (Zea mays L.. Three levels of plant populations (53000, 66000, and 800000 plants ha−1 corresponding to spacings of 75 × 25, 60 × 25, and 50 × 25 cm and 4 doses of N (100, 140, 180, and 220 kg ha−1 were the treatment variables. Results revealed that plant growth, light interception (LI, yield attributes, and grain yield varied significantly due to the variations in population density and N-rates. Crop growth rate (CGR was the highest with the population of 80,000 ha−1 receiving 220 kg N ha−1, while relative growth rate (RGR showed an opposite trend of CGR. Light absorption was maximum when most of densely populated plant received the highest amount of N (220 kg N ha−1. Response of soil-plant-analysis development (SPAD value as well as N-content to N-rates was found significant. Plant height was the maximum at the lowest plant density with the highest amount of N. Plants that received 180 kg N ha−1 with 80,000 plants ha−1 had larger foliage, greater SPAD value, and higher amount of grains cob−1 that contributed to the maximum yield (5.03 t ha−1 and the maximum harvest index (HI compared to the plants in other treatments.

  15. The health status of the population neighbouring the nuclear power plants in Slovakia

    International Nuclear Information System (INIS)

    Letkovicova, M.; Letkovicova, H.; Branislav Mihaly, B.; Stehlikova, B.

    2003-01-01

    The objective of this study is to ascertain the actual state of the indicators of health in individual villages within the area under investigation, to ascertain the trend of the development of indicators in the area surrounding the nuclear power plant included in the study, to find whether the occurrence of an indicator is accidental or whether it is determined in the village, make a comparison with another area and with the situation in the Slovak Republic as a whole and, consequently, to determine possible influence of the Power Plant on the indicator's value. It is concluded, that objective and comprehensive evaluation of the health of the population of Slovakia is possible. Enough solid and reliable proofs are available to justify the conclusion that, regardless of the length of the power plants' operation, no unfavourable impacts on human health on their territory have been detected even by the most sophisticated research carried out by a large, multidisciplinary team of researchers from various fields of science

  16. Incidence of plant cover over the autotrophic nitrifying bacteria population in a fragment of Andean forest

    International Nuclear Information System (INIS)

    Gonzalez, Xiomara; Gonzalez, L; Varela, A; Ahumada, J A

    1999-01-01

    It was determined the incidence of plant cover (forest vs. pasture), on the autotrophy nitrifying bacteria, through the effect of biotic factors (radical exudate) and abiotic factors (temperature, ph and humidity), in a high mountain cloud forest fragment. The site of study was located near La Mesa (Cundinamarca) municipality. The temperature of soil was measured in situ, and soil samples were collected and carried to the laboratory for pH and humidity percentage measurements. Serial soil dilution method was used for plating samples on a selective culture medium with ammonium sulphate as nitrogen source, in order to estimate the autotrophic nitrifying bacteria population levels. Grown colonies were examined macro and microscopically. The quantity of nitrates produced by bacteria cultured in vitro was determined spectra-photometrical. In relation to the abiotic factors, there was no significant differences of pH between both plant covers, but there were significant for soil humidity and temperature (p<0.05). There were highly significant differences with respect to the bacteria population levels (p<0.0001) and with respect to nitrate production. This suggests a higher bacterial activity in the under forest cover. The radical exudate from both types of plant cover reduced the viability of bacteria in vitro, from 1:1 to 1:30 exudate bacteria proportions. In the soils physical and chemical analysis, it was found a higher P and Al concentrations, and a higher CIC and organic matter content under the forest cover. It is suggested the importance of this functional group in this ecosystem

  17. Plant Community Richness Mediates Inhibitory Interactions and Resource Competition between Streptomyces and Fusarium Populations in the Rhizosphere.

    Science.gov (United States)

    Essarioui, Adil; LeBlanc, Nicholas; Kistler, Harold C; Kinkel, Linda L

    2017-07-01

    Plant community characteristics impact rhizosphere Streptomyces nutrient competition and antagonistic capacities. However, the effects of Streptomyces on, and their responses to, coexisting microorganisms as a function of plant host or plant species richness have received little attention. In this work, we characterized antagonistic activities and nutrient use among Streptomyces and Fusarium from the rhizosphere of Andropogon gerardii (Ag) and Lespedeza capitata (Lc) plants growing in communities of 1 (monoculture) or 16 (polyculture) plant species. Streptomyces from monoculture were more antagonistic against Fusarium than those from polyculture. In contrast, Fusarium isolates from polyculture had greater inhibitory capacities against Streptomyces than isolates from monoculture. Although Fusarium isolates had on average greater niche widths, the collection of Streptomyces isolates in total used a greater diversity of nutrients for growth. Plant richness, but not plant host, influenced the potential for resource competition between the two taxa. Fusarium isolates had greater niche overlap with Streptomyces in monoculture than polyculture, suggesting greater potential for Fusarium to competitively challenge Streptomyces in monoculture plant communities. In contrast, Streptomyces had greater niche overlap with Fusarium in polyculture than monoculture, suggesting that Fusarium experiences greater resource competition with Streptomyces in polyculture than monoculture. These patterns of competitive and inhibitory phenotypes among Streptomyces and Fusarium populations are consistent with selection for Fusarium-antagonistic Streptomyces populations in the presence of strong Fusarium resource competition in plant monocultures. Similarly, these results suggest selection for Streptomyces-inhibitory Fusarium populations in the presence of strong Streptomyces resource competition in more diverse plant communities. Thus, landscape-scale variation in plant species richness may be

  18. PREPP [Process Experimental Pilot Plant] rotary kiln seals: Problem and resolution

    International Nuclear Information System (INIS)

    Drexler, R.L.

    1990-01-01

    The Process Experimental Pilot Plant (PREPP) is a facility designed to demonstrate processing of low level chemical and transuranic hazardous waste. The plant includes equipment for handling the incoming waste containers, shredding, incineration and cooling the waste, grouting the residue and scrubbing and filtration of the off gas. The process incinerator is a rotary kiln approximately 8-1/2 ft diameter and 25 ft long with a rotary seal assembly at each end. Each seal assembly consists of a primary, secondary and tertiary seal, with a positive air pressure between primary and secondary seals to prevent out-leakage from the kiln. The kiln operates at 0.5 inch water negative pressure. From the very outset the kiln seals exhibited excessive drag which taxed the kiln drive capacity and excessive in-leakage which limited kiln temperature. An engineering evaluation concluded that the original seals supplied by the kiln vendor could not accommodate expansion and centerline shift of the kiln resulting from heatup of the kiln and its support system. A totally new concept kiln seal design has been generated to replace the (modified) original seals. This new seal system has been designed to provide a very tight long lasting seal which will accommodate the 1.5 inch axial shift and up to 1 inch radial movement of the kiln shell. Design lifetime of the seal is 10,000 operating hours between major maintenance services while maintaining an acceptable leak rate hot or cold, rotating or stopped. The design appears adaptable to any size kiln and is suitable for retrofit to existing kilns. A one-third scale prototype seal assembly is being built to verify the concept prior to construction of the 10 ft diameter seals for the PREPP rotary kiln. 4 figs

  19. Patch size effects on plant species decline in an experimentally fragmented landscape.

    Science.gov (United States)

    Collins, Cathy D; Holt, Robert D; Foster, Bryan L

    2009-09-01

    Understanding local and global extinction is a fundamental objective of both basic and applied ecology. Island biogeography theory (IBT) and succession theory provide frameworks for understanding extinction in changing landscapes. We explore the relative contribution of fragment size vs. succession on species' declines by examining distributions of abundances for 18 plant species declining over time in an experimentally fragmented landscape in northeast Kansas, U.S.A. If patch size effects dominate, early-successional species should persist longer on large patches, but if successional processes dominate, the reverse should hold, because in our system woody plant colonization is accelerated on large patches. To compare the patterns in abundance among patch sizes, we characterize joint shifts in local abundance and occupancy with a new metric: rank occupancy-abundance profiles (ROAPs). As succession progressed, statistically significant patch size effects emerged for 11 of 18 species. More early-successional species persisted longer on large patches, despite the fact that woody encroachment (succession) progressed faster in these patches. Clonal perennial species persisted longer on large patches compared to small patches. All species that persisted longer on small patches were annuals that recruit from the seed bank each year. The degree to which species declined in occupancy vs. abundance varied dramatically among species: some species declined first in occupancy, others remained widespread or even expanded their distribution, even as they declined in local abundance. Consequently, species exhibited various types of rarity as succession progressed. Understanding the effect of fragmentation on extinction trajectories requires a species-by-species approach encompassing both occupancy and local abundance. We propose that ROAPs provide a useful tool for comparing the distribution of local abundances among landscape types, years, and species.

  20. A multi-agent architecture for sharing knowledge and experimental data about waste water treatment plants through the Internet

    International Nuclear Information System (INIS)

    Abu Yaman, I. R.; Kerckhoffs, J. E.

    1998-01-01

    In this paper, we present a first prototype of a local multi-agent architecture for the sharing of knowledge and experimental data about waste water treatment plants through the Internet, or more specifically the WWW. Applying a net browser such as nets cape, a user can have access to a CLIPS expert system (advising on waste water cleaning technologies) and experimental data files. The discussed local prototype is part of proposed global agent architecture. (authors)

  1. Experimental defoliation affects male but not female reproductive performance of the tropical monoecious plant Croton suberosus (Euphorbiaceae).

    Science.gov (United States)

    Narbona, Eduardo; Dirzo, Rodolfo

    2010-08-01

    Monoecious plants have the capacity to allocate resources separately to male and female functions more easily than hermaphrodites. This can be advantageous against environmental stresses such as leaf herbivory. However, studies showing effects of herbivory on male and female functions and on the interaction with the plant's pollinators are limited, particularly in tropical plants. Here, the effects of experimental defoliation were examined in the monoecious shrub Croton suberosus (Euphorbiaceae), a wasp-pollinated species from a Mexican tropical dry forest. Three defoliation treatments were applied: 0 % (control), 25 % (low) or 75 % (high) of plant leaf area removed. Vegetative (production of new leaves) and reproductive (pistillate and staminate flower production, pollen viability, nectar production, fruit set, and seed set) performance variables, and the abundance and activity of floral visitors were examined. Defoliated plants overcompensated for tissue loss by producing more new leaves than control plants. Production of staminate flowers gradually decreased with increasing defoliation and the floral sex ratio (staminate : pistillate flowers) was drastically reduced in high-defoliation plants. In contrast, female reproductive performance (pistillate flower production, fruit set and seed set) and pollinator visitation and abundance were not impacted by defoliation. The asymmetrical effects of defoliation on male and female traits of C. suberosus may be due to the temporal and spatial flexibility in the allocation of resources deployed by monoecious plants. We posit that this helps to maintain the plant's pollination success in the face of leaf herbivory stress.

  2. Population Growth Parameters of Tuta absoluta (Lepidoptera: Gelechiidae) on Tomato Plant Using Organic Substrate and Biofertilizers.

    Science.gov (United States)

    Mohamadi, P; Razmjou, J; Naseri, B; Hassanpour, M

    2017-01-01

    The tomato leafminer, Tuta absoluta (Meyrick) is a devastating pest associated with tomato. In this study, effects of tomato plants treated with vermicompost (20, 40, and 60%), humic fertilizer (2, 4 and 6 g/kg soil) and plant growth promoting rhizobacteria (Pseudomonas fluorescens and Bacillus subtilis) were investigated on the life table parameters of T. absoluta in a growth chamber at 25 ± 2 °C, 65 ± 5% RH, and 16:8 (L:D) h. Significant differences were found for the total developmental time, fecundity, and oviposition period of T. absoluta on the treatments tested. The net reproductive rate (R0), intrinsic rate of natural increase (rm), finite rate of increase (λ), mean generation time (T), and doubling time (DT) of T. absoluta were significantly different among treatments tested. We found that in all vermicompost, humic fertilizer and plant growth promoting rhizobacteria treatments, values of R0, rm, and λ were lower than control treatment. However, the lowest values of these parameters were obtained on 2 g/kg humic fertilizer and 40% vermicompost. Furthermore, T. absoluta had longest T and DT values on 2 g/kg humic fertilizer treatment. Data obtained showed that the addition of 2 g/kg humic fertilizer and 40% vermicompost to the growing soil reduced T. absoluta populations in tomato cultures. In addition, these levels of fertilizers improved growth parameters of tomato seedlings (plant height, wet weight, and dry weight) compared with other treatments. These results could be useful in improving the sustainable management of the moth. © The Author 2017. Published by Oxford University Press on behalf of the Entomological Society of America.

  3. Ways of adaptation of the plant populations to chemical and radioactive contamination

    International Nuclear Information System (INIS)

    Pozolotina, V.; Bezel', V.; Zhuykova, T.; Severu'Khina, O.; Ulyanova, E.

    2004-01-01

    Chemical agents (heavy metals, acids, etc.) and radiation render their influence upon biota being clearly distinct in primary mechanisms of action. However, lively organisms demonstrate one and the same set [arsenal] of response reactions, and thus it is important to reveal the ways of their realization caused by different types of techno-genic impacts. Our work was intended to examine the seed progeny of the dandelion, Taraxacum officinale, from radionuclides-contaminated coeno-populations (grown at the territories influenced by Eastern-Ural radioactive trace, in the Techa-river flood plain) and those situated in the nearest impact zone affected by a large metallurgical plant in the Urals. Plots, differently distanced from the enterprise, showed heavy metal contamination loads 8-33 times higher than the control site did. Radionuclides concentrations ( 90 Sr and 137 Cs) within the contaminated zone exceeded the background values 4-40 times. The study allowed estimation of the seed progeny vitality level for different coeno-populations, comparison of their adaptive potential in regard to heavy metals tolerance and gamma radiation resistance, estimation of abnormal seedlings [sprouts] frequency values. It was shown [found] that under techno-genic pollution the dandelion coeno-populations usually demonstrate wider variations of different characteristics (vitality, mutability, root and leaf growth rates) as compared to those in the background zone. As a general regularity one can regard the phenomenon, that negative effects were not marked to be increased by heavier pollution loads, irrespectively of the agents nature. (author)

  4. Some Genetic Characteristics of the Population Residing Nearby Nuclear Power Plant. The First Step

    International Nuclear Information System (INIS)

    Mkheidze, M.

    2007-01-01

    There is Sosnovy Bor with 60 thousands of inhabitants located 80 km to the west from the centre of St. Petersburg. Here is the greatest and the oldest nuclear power plant, LNPP, with four reactors of the RMBK-1000 (Chernobyl) type. In fact every Sosnovy Bor inhabitant is connected with nuclear technologies. The strategy of the city development is formed and controlled by the policy of federal bodies. It is very difficult to have access to any demographic data and documents reflecting status of population health. Low doses of ionizing radiation are known to cause mutations in germ cells. A great part of the population of Sosnovy Bor works in the NPP and is exposed to low dose ionizing radiation. This paper presents some genetic characteristics of Sosnovy Bor inhabitants including monogenic diseases (phenylketonuria, Duchenne muscular dystrophy, lysosomal diseases, hypothyroidism etc), chromosomal pathology (Down syndrome, Turner and Klinefelter diseases), multiple malformation syndromes and results of aFP screening of pregnant women with high rate of abnormal values of aFP and hHG. These results are obligatory basis and the first step to conduct a study on possible genetic effects of LNPP on genetic structure of Sosnovy Bor population.(author)

  5. The Effect of Organic Fertilizers and Flowering Plants on Sheet-Web and Wolf Spider Populations (Araneae: Lycosidae and Linyphiidae) and Its Importance for Pest Control.

    Science.gov (United States)

    El-Nabawy, El-Said M; Tsuda, Katsuo; Sakamaki, Yositaka; Oda, Asahi; Ushijima, Yurie

    2016-01-01

    The main goal of this study was to identify the treatment that increases the populations of spiders, which are effective predators in agroecosystems. In 2013 and 2014 the experimental eggplant (Solanum melongena L.) field was two different treatments, organic fertilizers and chemical fertilizer treatment, and in 2014 we surrounded organic fertilizer plots with the flowering plants mealy cup sage (Salvia farinacea Benth.), spearmint (Mentha spicata L.), and basil (Ocimum basilicum L.). Analysis using repeated measures ANOVA revealed significant influences of fertilizer type on the numbers of linyphiid spiders and Collembola in 2013. In 2014, the numbers of Collembola, thrips, and lycosid and linyphiid spider were higher in organic fertilizer with flowering plants treatment comparing with the chemical fertilizer treatment. Moreover, the numbers of Henosepilachna vigintioctopunctata (F.) were significantly lower in the organic fertilizer with flowering plants treatment than in chemical fertilizers treatment. Finally, we expect that Thysanoptera and Collembola were important alternative prey for linyphiid and lycosid spiders and the use of organic fertilizer and flowering plants enhanced the density of these spiders, and may increase their effectiveness in suppressing the populations of H. vigintioctopunctata (F.). © The Author 2016. Published by Oxford University Press on behalf of the Entomological Society of America.

  6. Creating new populations of Apium bermejoi (Apiaceae, a critically endangered endemic plant on Menorca (Balearic Islands

    Directory of Open Access Journals (Sweden)

    Rita, Juan

    2013-06-01

    Full Text Available Apium bermejoi is a stoloniferous plant endemic to the island of Menorca (Balearic Islands. It is found only at one locality, and it is listed as Critically Endangered (according to the IUCN criteria. We describe the main results of population restoration actions undertaken under the Recovery Plan for this species, including the following: 1 introduction at two new localities (2008, 2 reinforcement of the original wild and the introduced populations, and 3 a programme for monitoring population dynamics (including both wild and introduced populations spanning four years (2006-2010. The plant material for the introduction and reinforcement projects was generated from seeds gathered in the wild. We carried out a monthly census of all of the individuals/patches and emerged seedlings, from which we assessed their survival at 3-4months. The survival rates of the planted individuals in the two new localities after three months were found to be 59.0% and 56.3%, and more than 80% of the surviving plants produced fruits. A seasonal pattern was observed based on the minimum cover values recorded in the censuses taken at the end of summer, with an increase detected during autumn, and maximal cover values recorded during May/June. The A. bermejoi populations showed large inter-annual fluctuations in both the number of patches and area of occupancy. The number of seedlings varied across the study years, and their survival was linked to specific meteorological events, such as severe storms and dry and hot spells during autumn. The initial phase of introduction for this species has been overall successful, but a final evaluation can only be made on a longterm basis.Apium bermejoi, planta estolonífera endémica de Menorca (Islas Baleares, de la que se conoce una sola localidad en el medio natural, está considerada en Peligro Crítico de extinción (según criterios UICN. Se presentan los principales resultados de las acciones de restauración de las

  7. Changes in plant species richness induce functional shifts in soil nematode communities in experimental grassland.

    Directory of Open Access Journals (Sweden)

    Nico Eisenhauer

    Full Text Available Changes in plant diversity may induce distinct changes in soil food web structure and accompanying soil feedbacks to plants. However, knowledge of the long-term consequences of plant community simplification for soil animal food webs and functioning is scarce. Nematodes, the most abundant and diverse soil Metazoa, represent the complexity of soil food webs as they comprise all major trophic groups and allow calculation of a number of functional indices.We studied the functional composition of nematode communities three and five years after establishment of a grassland plant diversity experiment (Jena Experiment. In response to plant community simplification common nematode species disappeared and pronounced functional shifts in community structure occurred. The relevance of the fungal energy channel was higher in spring 2007 than in autumn 2005, particularly in species-rich plant assemblages. This resulted in a significant positive relationship between plant species richness and the ratio of fungal-to-bacterial feeders. Moreover, the density of predators increased significantly with plant diversity after five years, pointing to increased soil food web complexity in species-rich plant assemblages. Remarkably, in complex plant communities the nematode community shifted in favour of microbivores and predators, thereby reducing the relative abundance of plant feeders after five years.The results suggest that species-poor plant assemblages may suffer from nematode communities detrimental to plants, whereas species-rich plant assemblages support a higher proportion of microbivorous nematodes stimulating nutrient cycling and hence plant performance; i.e. effects of nematodes on plants may switch from negative to positive. Overall, food web complexity is likely to decrease in response to plant community simplification and results of this study suggest that this results mainly from the loss of common species which likely alter plant-nematode interactions.

  8. Experimental charcoalification of plant reproductive organs: Taphonomic implications for taxonomic information loss

    Energy Technology Data Exchange (ETDEWEB)

    Lupia, R. (Univ. of Chicago, IL (United States))

    1992-01-01

    Charcoalification can preserve reproductive organs of plants in exceptional detail, but it has not been clear to what extent these taxonomically important structures suffer non-allometric size reduction during this process. To address this problem, seven angiosperm and two gymnosperm species were buried in sand and experimentally charcoalified in a muffle furnace at 325--350 degrees Celsius for two hours, and percent size reduction measured. Carpels, stamens, and petals never shrank by the same amount for a given angiosperm species. To determine the effect of different periods of heating on organs, one angiosperm species was treated for 0.5, 1, 2, 4, and 6 hours. Organs continued to shrink over this entire period without reaching a plateau. This is important in designing future experiments, and in terms of interpreting fossils, since heat treatment varies across a single site in natural fires. Observations made during this study suggest that some carpels and petals never become charcoalified, that stamens are particularly susceptible to fragmentation after charcoalification, that some organs show predictable damage which is correlated with time, and that the saturation of a structure with water can significantly retard charcoalification for heat exposure of less than one hour. These factors may severely affect the entry of the charred remains into the fossil record. Despite the suggestion that female structures can be expected to shrink the least, it is impossible to prescribe quantitative correction factors to permit accurate reconstructions without constraining additional variables such as temperature and duration of heating.

  9. Experimental bypass of Lake Reality, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1997-10-01

    Studies conducted by the Y-12 Reduction of Mercury in Plant Effluent (RMPE) Program and Y-12 Biological Monitoring and Abatement Program (BMAP) in 1995 and 1996 (Y/ER-251, Y/ER-277) identified concerns regarding Lake Reality's effect on the transport and transformation of mercury in East Fork Poplar Creek (EFPC). The pond appeared to have two potentially adverse effects on mercury transport. First, it acted as a biochemical reactor, converting inorganic mercury in inflowing water to methylmercury, a more toxic substance with extremely high bioaccumulation potential in aquatic environments. Second, the pond appeared to trap mercury associated with suspended particulates during periods of stormflow, and slowly released that mercury via the export of resuspended particles during periods of baseflow. The net effect was to raise the day-to-day exposure of aquatic life to mercury in the stream downstream from the pond, and add to the calculated mercury loading of the stream under baseflow conditions. Scientific investigations thus indicated that diversion of the flow of EFPC around Lake Reality had the potential to reduce time-averaged concentrations of methylmercury and total mercury in the creek below its discharge, but that such diversion might also interfere with possible beneficial effects of the retention pond. Therefore, an experimental bypass of the pond was undertaken in late 1996 to evaluate the consequences of such an action before embarking on a more permanent change

  10. A novel approach to parasite population genetics: experimental infection reveals geographic differentiation, recombination and host-mediated population structure in Pasteuria ramosa, a bacterial parasite of Daphnia.

    Science.gov (United States)

    Andras, J P; Ebert, D

    2013-02-01

    The population structure of parasites is central to the ecology and evolution of host-parasite systems. Here, we investigate the population genetics of Pasteuria ramosa, a bacterial parasite of Daphnia. We used natural P. ramosa spore banks from the sediments of two geographically well-separated ponds to experimentally infect a panel of Daphnia magna host clones whose resistance phenotypes were previously known. In this way, we were able to assess the population structure of P. ramosa based on geography, host resistance phenotype and host genotype. Overall, genetic diversity of P. ramosa was high, and nearly all infected D. magna hosted more than one parasite haplotype. On the basis of the observation of recombinant haplotypes and relatively low levels of linkage disequilibrium, we conclude that P. ramosa engages in substantial recombination. Isolates were strongly differentiated by pond, indicating that gene flow is spatially restricted. Pasteuria ramosa isolates within one pond were segregated completely based on the resistance phenotype of the host-a result that, to our knowledge, has not been previously reported for a nonhuman parasite. To assess the comparability of experimental infections with natural P. ramosa isolates, we examined the population structure of naturally infected D. magna native to one of the two source ponds. We found that experimental and natural infections of the same host resistance phenotype from the same source pond were indistinguishable, indicating that experimental infections provide a means to representatively sample the diversity of P. ramosa while reducing the sampling bias often associated with studies of parasite epidemics. These results expand our knowledge of this model parasite, provide important context for the large existing body of research on this system and will guide the design of future studies of this host-parasite system. © 2012 Blackwell Publishing Ltd.

  11. Experimental test of an eco-evolutionary dynamic feedback loop between evolution and population density in the green peach aphid.

    Science.gov (United States)

    Turcotte, Martin M; Reznick, David N; Daniel Hare, J

    2013-05-01

    An eco-evolutionary feedback loop is defined as the reciprocal impacts of ecology on evolutionary dynamics and evolution on ecological dynamics on contemporary timescales. We experimentally tested for an eco-evolutionary feedback loop in the green peach aphid, Myzus persicae, by manipulating initial densities and evolution. We found strong evidence that initial aphid density alters the rate and direction of evolution, as measured by changes in genotype frequencies through time. We also found that evolution of aphids within only 16 days, or approximately three generations, alters the rate of population growth and predicts density compared to nonevolving controls. The impact of evolution on population dynamics also depended on density. In one evolution treatment, evolution accelerated population growth by up to 10.3% at high initial density or reduced it by up to 6.4% at low initial density. The impact of evolution on population growth was as strong as or stronger than that caused by a threefold change in intraspecific density. We found that, taken together, ecological condition, here intraspecific density, alters evolutionary dynamics, which in turn alter concurrent population growth rate (ecological dynamics) in an eco-evolutionary feedback loop. Our results suggest that ignoring evolution in studies predicting population dynamics might lead us to over- or underestimate population density and that we cannot predict the evolutionary outcome within aphid populations without considering population size.

  12. Paternal leakage of mitochondrial DNA in experimental crosses of populations of the potato cyst nematode Globodera pallida.

    Science.gov (United States)

    Hoolahan, Angelique H; Blok, Vivian C; Gibson, Tracey; Dowton, Mark

    2011-12-01

    Animal mtDNA is typically assumed to be maternally inherited. Paternal mtDNA has been shown to be excluded from entering the egg or eliminated post-fertilization in several animals. However, in the contact zones of hybridizing species and populations, the reproductive barriers between hybridizing organisms may not be as efficient at preventing paternal mtDNA inheritance, resulting in paternal leakage. We assessed paternal mtDNA leakage in experimental crosses of populations of a cyst-forming nematode, Globodera pallida. A UK population, Lindley, was crossed with two South American populations, P5A and P4A. Hybridization of these populations was supported by evidence of nuclear DNA from both the maternal and paternal populations in the progeny. To assess paternal mtDNA leakage, a ~3.4 kb non-coding mtDNA region was analyzed in the parental populations and in the progeny. Paternal mtDNA was evident in the progeny of both crosses involving populations P5A and P4A. Further, paternal mtDNA replaced the maternal mtDNA in 22 and 40 % of the hybrid cysts from these crosses, respectively. These results indicate that under appropriate conditions, paternal leakage occurs in the mtDNA of parasitic nematodes, and supports the hypothesis that hybrid zones facilitate paternal leakage. Thus, assumptions of strictly maternal mtDNA inheritance may be frequently violated, particularly when divergent populations interbreed.

  13. THE EFFECTS OF POPULATION-SIZE AND PLANT-DENSITY ON OUTCROSSING RATES IN LOCALLY ENDANGERED SALVIA-PRATENSIS

    NARCIS (Netherlands)

    VANTREUREN, R; BIJLSMA, R; OUBORG, NJ; VANDELDEN, W

    Multilocus outcrossing rates were estimated in natural and experimental populations of Salvia pratensis, an entomophilous, gynodioecious, protandrous perennial. Male steriles were used to check the estimation procedure of outcrossing rates in hermaphrodites. Estimates of outcrossing rates in

  14. A realistic approach to modeling an in-duct desulfurization process based on an experimental pilot plant study

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, F.J.G.; Ollero, P. [University of Seville, Seville (Spain)

    2008-07-15

    This paper has been written to provide a realistic approach to modeling an in-duct desulfurization process and because of the disagreement between the results predicted by published kinetic models of the reaction between hydrated lime and SO{sub 2} at low temperature and the experimental results obtained in pilot plants where this process takes place. Results were obtained from an experimental program carried out in a 3-MWe pilot plant. Additionally, five kinetic models, from the literature, of the reaction of sulfation of Ca(OH){sub 2} at low temperatures were assessed by simulation and indicate that the desulfurization efficiencies predicted by them are clearly lower than those experimentally obtained in our own pilot plant as well as others. Next, a general model was fitted by minimizing the difference between the calculated and the experimental results from the pilot plant, using Matlab{sup TM}. The parameters were reduced as much as possible, to only two. Finally, after implementing this model in a simulation tool of the in-duct sorbent injection process, it was validated and it was shown to yield a realistic approach useful for both analyzing results and aiding in the design of an in-duct desulfurization process.

  15. Nonnative invasive plants in the Penobscot Experimental Forest in Maine, USA: influence of site, silviculture, and land use history

    Science.gov (United States)

    Elizabeth Olson; Laura S. Kenefic; Alison C. Dibble; John C. Brissette

    2011-01-01

    We investigated the occurrence of nonnative invasive plants on approximately 175 ha comprising a long-term, 60-year-old U.S. Forest Service silvicultural experiment and old-field stands in the Penobscot Experimental Forest (PEF) in central Maine. Stands in the silvicultural experiment were never cleared for agriculture, but have been repeatedly partially cut. Our...

  16. Experimental and kinetic modelling studies on the acid-catalysed hydrolysis of the water hyacinth plant to levulinic acid

    NARCIS (Netherlands)

    Girisuta, B.; Danon, B.; Manurung, R.; Janssen, L. P. B. M.; Heeres, H. J.

    2008-01-01

    A comprehensive experimental and modelling study on the acid-catalysed hydrolysis of the water hyacinth plant (Eichhornia crassipes) to optimise the yield of levulinic acid (LA) is reported (T = 150-175 degrees C, C-H2SO4 - 0.1-1 M, water hyacinth intake = 1-5 wt%). At high acid concentrations (>

  17. Computer simulation model for the striped bass young-of-the-year population in the Hudson River. [Effects of entrainment and impingement at power plants on population dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Eraslan, A.H.; Van Winkle, W.; Sharp, R.D.; Christensen, S.W.; Goodyear, C.P.; Rush, R.M.; Fulkerson, W.

    1975-09-01

    This report presents a daily transient (tidal-averaged), longitudinally one-dimensional (cross-section-averaged) computer simulation model for the assessment of the entrainment and impingement impacts of power plant operations on young-of-the-year populations of the striped bass, Morone saxatilis, in the Hudson River.

  18. Population dose commitments due to radioactive releases from nuclear power plant sites in 1988

    International Nuclear Information System (INIS)

    Baker, D.A.

    1992-01-01

    Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1988. Fifty-year commitments for a one-year exposure from both liquid and atmospheric releases were calculated for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 71 reactor sites. This report tabulates the results of these calculations, showing the dose commitments for both water and airborne pathways for each age group and organ. Also included for each of the sites is a histogram showing the fraction of the total population within 2 to 80 km around each site receiving various average dose commitments from the airborne pathways. The total collective dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 16 person-rem to a low of 0.0011 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 1.1 person-rem. The total population dose for all sites was estimated at 75 person-rem for the 150 million people considered at risk. The site average individual dose commitment from all pathways ranged from a low of 3 x 10 -7 mrem to a high of 0.02 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites. However, licensee calculation of doses to the maximally exposed individual at some sites indicated values of up to approximately 100 times average individual doses (on the order of a few millirem per year)

  19. How do earthworms, soil texture and plant composition affect infiltration along an experimental plant diversity gradient in grassland?

    Science.gov (United States)

    Fischer, Christine; Roscher, Christiane; Jensen, Britta; Eisenhauer, Nico; Baade, Jussi; Attinger, Sabine; Scheu, Stefan; Weisser, Wolfgang W; Schumacher, Jens; Hildebrandt, Anke

    2014-01-01

    Infiltration is a key process in determining the water balance, but so far effects of earthworms, soil texture, plant species diversity and their interaction on infiltration capacity have not been studied. We measured infiltration capacity in subplots with ambient and reduced earthworm density nested in plots of different plant species (1, 4, and 16 species) and plant functional group richness and composition (1 to 4 groups; legumes, grasses, small herbs, tall herbs). In summer, earthworm presence significantly increased infiltration, whereas in fall effects of grasses and legumes on infiltration were due to plant-mediated changes in earthworm biomass. Effects of grasses and legumes on infiltration even reversed effects of texture. We propose two pathways: (i) direct, probably by modifying the pore spectrum and (ii) indirect, by enhancing or suppressing earthworm biomass, which in turn influenced infiltration capacity due to change in burrowing activity of earthworms. Overall, the results suggest that spatial and temporal variations in soil hydraulic properties can be explained by biotic processes, especially the presence of certain plant functional groups affecting earthworm biomass, while soil texture had no significant effect. Therefore biotic parameters should be taken into account in hydrological applications.

  20. How do earthworms, soil texture and plant composition affect infiltration along an experimental plant diversity gradient in grassland?

    Directory of Open Access Journals (Sweden)

    Christine Fischer

    Full Text Available BACKGROUND: Infiltration is a key process in determining the water balance, but so far effects of earthworms, soil texture, plant species diversity and their interaction on infiltration capacity have not been studied. METHODOLOGY/PRINCIPAL FINDINGS: We measured infiltration capacity in subplots with ambient and reduced earthworm density nested in plots of different plant species (1, 4, and 16 species and plant functional group richness and composition (1 to 4 groups; legumes, grasses, small herbs, tall herbs. In summer, earthworm presence significantly increased infiltration, whereas in fall effects of grasses and legumes on infiltration were due to plant-mediated changes in earthworm biomass. Effects of grasses and legumes on infiltration even reversed effects of texture. We propose two pathways: (i direct, probably by modifying the pore spectrum and (ii indirect, by enhancing or suppressing earthworm biomass, which in turn influenced infiltration capacity due to change in burrowing activity of earthworms. CONCLUSIONS/SIGNIFICANCE: Overall, the results suggest that spatial and temporal variations in soil hydraulic properties can be explained by biotic processes, especially the presence of certain plant functional groups affecting earthworm biomass, while soil texture had no significant effect. Therefore biotic parameters should be taken into account in hydrological applications.

  1. Living in isolation - population structure, reproduction, and genetic variation of the endangered plant species Dianthus gratianopolitanus (Cheddar pink).

    Science.gov (United States)

    Putz, Christina M; Schmid, Christoph; Reisch, Christoph

    2015-09-01

    The endangered plant species Dianthus gratianopolitanus exhibits a highly fragmented distribution range comprising many isolated populations. Based upon this pattern of distribution, we selected a study region in Switzerland with a lower magnitude of isolation (Swiss Jura) and another study region in Germany with a higher degree of isolation (Franconian Jura). In each region, we chose ten populations to analyze population structure, reproduction, and genetic variation in a comparative approach. Therefore, we determined population density, cushion size, and cushion density to analyze population structure, investigated reproductive traits, including number of flowers, capsules, and germination rate, and analyzed amplified fragment length polymorphisms to study genetic variation. Population and cushion density were credibly higher in German than in Swiss populations, whereas reproductive traits and genetic variation within populations were similar in both study regions. However, genetic variation among populations and isolation by distance were stronger in Germany than in Switzerland. Generally, cushion size and density as well as flower and capsule production increased with population size and density, whereas genetic variation decreased with population density. In contrast to our assumptions, we observed denser populations and cushions in the region with the higher magnitude of isolation, whereas reproductive traits and genetic variation within populations were comparable in both regions. This corroborates the assumption that stronger isolation must not necessarily result in the loss of fitness and genetic variation. Furthermore, it supports our conclusion that the protection of strongly isolated populations contributes essentially to the conservation of a species' full evolutionary potential.

  2. Impact Of Different Time Planting In Soybeans And Neem Seed Extract Application To Insect Population On Rice Field

    Directory of Open Access Journals (Sweden)

    Tamrin Abdullah

    2015-08-01

    Full Text Available Abstract The purpose of research is to study impact of different time planting of soybean and neem seed extract application to pest insect population on rice field. The research was used Random Block Design in three treatment of insecticides application i.e neem seed extract together with rice planting neem seed extract on soybean 17 days after rice planting synthetic insecticides on 17 days after rice planting Delthametrin on soybean and Chlorpirifos on rice respectively. Research was conducted in rice fields with irrigation channels. The land area is 0.8 hectares with extensive experiments each rice terraces approximately 900 m2 with separate by rice terraces for every treatment. Each treatment consisted of three groups and using nine rice terraces. Samples of the rice plant population is 25 plants per sample unit. The results was showed treatment by neem seed extract with different time planting of soybeans able to reduce number of pest insects populations such as N. virescens 80.38 N. lugens 67.17 S. incertulas 66.5 and L. oratorius 93.46 when compared to treatment with synthetic insecticides Delthamethrin and Chlorpyrifos.

  3. Taxonomic structure and population level of colon microbial contents in white rats with experimental thyrotoxicosis

    Directory of Open Access Journals (Sweden)

    L.I. Sydorchuk

    2017-08-01

    Full Text Available Background. Production of numerous biologically active compounds and their metabolites by intestinal microflora, interaction with the immune and other systems is of great importance while studying its changes in various diseases, one of which is thyrotoxicosis. So, the purpose of this study was to determine the severity of intestine microbioma disorder in white rats with experimental thyrotoxicosis (ET. Materials and methods. Studies were carried out on 25 mature male white rats (15 — control group, 10 — research group. ET was simulated by intragastric administration of L-thyroxine for 14 days. Under sterile conditions a laparotomy was performed, a section (2–3 cm of the large intestine with its contents was taken. Sterile 0.9% NaCl solution was added to the content. Series of ten-fold dilutions with a concentration of the initial mixture of 10–2 to 10–11 was prepared. From each test tube 0.01 ml was seeded on solid nutrient media with subsequent isolation and identification of microbes according to morphological, tinctorial, cultural and biochemical properties. Results. The results of the study demonstrated that in ET animals the main microbioma is represented by bacteria Bifidobacterium, Lactobacillus, Bacteroides, and also opportunistic enterobacteria (Escherichia, Proteus, Klebsiella, peptococcus, staphylococci and clostridia. This is accompanied by the elimination of Peptostreptococcus, Enterococcus from bacterial biotope and the contamination of K. oxytoca and staphylococci. There was a pronounced deficit of bifidobacteria by 42.81 %, lactobacillus by 22.57 %, normal intestinal bacillus by 16.48 %. By the population level, the coefficient of quantitative dominance and the significance factor, the leading place is occupied by bacteroids, role of which is increased by 21.72 %, and lactobacillus role decreases by 39.31 %, bifidobacteria decreases by 51.48 % and E. coli decreases by 57.49 %. In this case, the role of peptococcus 3

  4. Genetic Population Structure of Cacao Plantings within a Young Production Area in Nicaragua

    Science.gov (United States)

    Trognitz, Bodo; Scheldeman, Xavier; Hansel-Hohl, Karin; Kuant, Aldo; Grebe, Hans; Hermann, Michael

    2011-01-01

    Significant cocoa production in the municipality of Waslala, Nicaragua, began in 1961. Since the 1980s, its economic importance to rural smallholders increased, and the region now contributes more than 50% of national cocoa bean production. This research aimed to assist local farmers to develop production of high-value cocoa based on optimal use of cacao biodiversity. Using microsatellite markers, the allelic composition and genetic structure of cacao was assessed from 44 representative plantings and two unmanaged trees. The population at Waslala consists of only three putative founder genotype spectra (lineages). Two (B and R) were introduced during the past 50 years and occur in >95% of all trees sampled, indicating high rates of outcrossing. Based on intermediate allelic diversity, there was large farm-to-farm multilocus genotypic variation. GIS analysis revealed unequal distribution of the genotype spectra, with R being frequent within a 2 km corridor along roads, and B at more remote sites with lower precipitation. The third lineage, Y, was detected in the two forest trees. For explaining the spatial stratification of the genotype spectra, both human intervention and a combination of management and selection driven by environmental conditions, appear responsible. Genotypes of individual trees were highly diverse across plantings, thus enabling selection for farm-specific qualities. On-farm populations can currently be most clearly recognized by the degree of the contribution of the three genotype spectra. Of two possible strategies for future development of cacao in Waslala, i.e. introducing more unrelated germplasm, or working with existing on-site diversity, the latter seems most appropriate. Superior genotypes could be selected by their specific composite genotype spectra as soon as associations with desired quality traits are established, and clonally multiplied. The two Y trees from the forest share a single multilocus genotype, possibly representing the

  5. The Effect of Temperature and Host Plant Resistance on Population Growth of the Soybean Aphid Biotype 1 (Hemiptera: Aphididae).

    Science.gov (United States)

    Hough, Ashley R; Nechols, James R; McCornack, Brian P; Margolies, David C; Sandercock, Brett K; Yan, Donglin; Murray, Leigh

    2017-02-01

    A laboratory experiment was conducted to evaluate direct and indirect effects of temperature on demographic traits and population growth of biotype 1 of the soybean aphid, Aphis glycines Matsumura. Our objectives were to better understand how temperature influences the expression of host plant resistance, quantify the individual and interactive effects of plant resistance and temperature on soybean aphid population growth, and generate thermal constants for predicting temperature-dependent development on both susceptible and resistant soybeans. To assess indirect (plant-mediated) effects, soybean aphids were reared under a range of temperatures (15-30 °C) on soybean seedlings from a line expressing a Rag1 gene for resistance, and life history traits were quantified and compared to those obtained for soybean aphids on a susceptible soybean line. Direct effects of temperature were obtained by comparing relative differences in the magnitude of life-history traits among temperatures on susceptible soybeans. We predicted that temperature and host plant resistance would have a combined, but asymmetrical, effect on soybean aphid fitness and population growth. Results showed that temperature and plant resistance influenced preimaginal development and survival, progeny produced, and adult longevity. There also appeared to be a complex interaction between temperature and plant resistance for survival and developmental rate. Evidence suggested that the level of plant resistance increased at higher, but not lower, temperature. Soybean aphids required about the same number of degree-days to develop on resistant and susceptible plants. Our results will be useful for making predictions of soybean aphid population growth on resistant plants under different seasonal temperatures. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Evaluation of genetic diversity in wild populations of Peganum harmala L., a medicinal plant

    Directory of Open Access Journals (Sweden)

    Ranya EL-Bakatoushi

    2018-06-01

    Full Text Available Peganum harmala L. is a perennial herbaceous plant and can be a future drug due to its wide medicinal purposes. Despite its economic importance, the molecular genetics of P. harmal have not yet been studied in detail. Genetic diversity of 12 P. harmala genotypes were investigated by using Inter-Simple Sequence Repeats (ISSR, PCR-RFLP of rDNA-ITS, PCR-SSCP of rDNA-ITS and Simple Sequence Repeat (SSR markers. The level of polymorphism revealed by ITS-SSCP is the lowest, followed by ITS-RFLP then ISSR and the highest polymorphism level was reported for SSR marker. The AMOVA analysis implied that most of the variation occurred within the Populations. A value of inbreeding coefficient Fis estimated by the three co-dominant markers was nearly equal and offer an indication of the partial out-crossing reproductive system of P. harmala. Principal Coordinate Analysis (PCOA plot revealed a clear pattern of clustering based on the locations of collected plants which coincide with the isolation by distance. The study revealed that ITS-SSCP and ISSR markers respectively were more informative than the other used markers in the assessment of genetic diversity of P. harmala. The results reflect the great diversity of P. harmala and data obtained from this study can be used for future collecting missions. Keywords: Peganum harmala, Genetic diversity, ISSR, rDNA-ITS, SSR

  7. Experimental evolution reveals differences between phenotypic and evolutionary responses to population density.

    Science.gov (United States)

    McNamara, K B; Simmons, L W

    2017-09-01

    Group living can select for increased immunity, given the heightened risk of parasite transmission. Yet, it also may select for increased male reproductive investment, given the elevated risk of female multiple mating. Trade-offs between immunity and reproduction are well documented. Phenotypically, population density mediates both reproductive investment and immune function in the Indian meal moth, Plodia interpunctella. However, the evolutionary response of populations to these traits is unknown. We created two replicated populations of P. interpunctella, reared and mated for 14 generations under high or low population densities. These population densities cause plastic responses in immunity and reproduction: at higher numbers, both sexes invest more in one index of immunity [phenoloxidase (PO) activity] and males invest more in sperm. Interestingly, our data revealed divergence in PO and reproduction in a different direction to previously reported phenotypic responses. Males evolving at low population densities transferred more sperm, and both males and females displayed higher PO than individuals at high population densities. These positively correlated responses to selection suggest no apparent evolutionary trade-off between immunity and reproduction. We speculate that the reduced PO activity and sperm investment when evolving under high population density may be due to the reduced population fitness predicted under increased sexual conflict and/or to trade-offs between pre- and post-copulatory traits. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  8. Biodiesel purification methodology produced in the RECOPE experimental plant, using ion exchange resins

    International Nuclear Information System (INIS)

    Calderon Hernandez, Teresita

    2016-01-01

    A methodology was proposed for the biodisel purification of crude palm oil produced in a plant located on the Refinadora Costarricense de Petroleo (RECOPE) campus in Alto de Ochomogo, using ion exchange resins. A comparison between two resins was carried out: the USF C-211H, which had been acquired together with the RECOPE experimental plant and the PD206 resin, which was in the process of being acquired at the time of starting the project. The biodisel was eluted by glass columns packed with each resin, to determine the saturation of the same. The percentage of free and bound glycerin and the presence of soaps were analyzed as response variables. With the results obtained, it was determined that the PD206 resin is more efficient in the removal of glycerin, soaps and methanol than the resin USF C-211H. However, neither of the two resins diminishes the acidity of the biodisel. A biodisel sample was eluted by the PD206 resin and the quality of the obtained product was analyzed. A flash point of 145 degrees was obtained. A total acid number of 0.82 mg KOH / G was shown, no presence of water or sediment was observed. The percentage value of carbon residue was 0.01% m / m, the cloud point was 12 degrees, the density at 15 degrees was 0.8713 g / cm 3 , the viscosity at 40 degrees was 2.75 mm 2 /s; the stability to oxidation was 14.5 h, the percentage of free glycerin was 0.01% m / m and the percentage of total glycerin was 0.06% m / m, finally a percentage of Fatty Acids Methyl Esters (FAME) of 98,6%. Of the analyzed parameters, all are within the limits established in the Reglamento Tecnico Centroamericano except the acidity value, which exceeds the maximum value of 0.05 mg KOH / g sample. An economic analysis was carried out to evaluate which resin provides the best option to complete the purification process of the biodisel produced. The PD206, despite being more expensive, purifies a larger volume of biodiesel, so for a better negotiation in the purchase price, this

  9. Anthelmintic efficacy of five tropical native Australian plants against Haemonchus contortus and Trichostrongylus colubriformis in experimentally infected goats (Capra hircus).

    Science.gov (United States)

    Moreno, F C; Gordon, I J; Knox, M R; Summer, P M; Skerrat, L F; Benvenutti, M A; Saumell, C A

    2012-06-08

    The study of the anthelmintic properties of plants rich in plant secondary metabolites can provide ecologically sound methods for the treatment of parasites on grazing animals. The purpose of the present study was to evaluate the anthelmintic effect of five tropical native Australian plant species rich in plant secondary metabolites on adult Haemonchus contortus and Trichostrongylus colubriformis in experimentally infected goats. Thirty young, nematode-free goats were infected with 2500 H. contortus and 5000 T. colubriformis infective larvae thrice weekly for a week (day 1-7 of the experiment). On day 27 after first infection, the goats were allocated into six groups of five animals per group. From day 28 to day 35, fresh leaves from Acacia salicina, Acacia nilotica, Eucalyptus corymbia, Casuarina cunninghamiana and Eucalyptus drepanophylla were included in the goats diet. Five groups were offered leaves from one of these plant species and one group, the untreated control, received only the basal diet formulated with 20% Medicago sativa and 80% Avena sativa. Following plant material administration, the goats were monitored daily until day 40 and then slaughtered on day 41. Total faecal worm egg output, total production of larvae recovered from faecal cultures, total post-mortem worm burdens and the per capita fecundity of female worms were estimated. The toxicity of the plant species for the goats was measured by histopathological analyses of liver and kidney samples. Results showed that goats feeding on the plant material rich in plant secondary metabolites had significantly lower egg output compared to the control goats (P0.05), the per capita fecundity was significantly reduced by E. corymbia, A. nilotica and A. salicina (Pgoats can benefit from the short-term ingestion of plant secondary metabolites, which reduce the total faecal egg output and thus decrease the potential for re-infection from the pasture. Crown Copyright © 2012. Published by Elsevier B.V. All

  10. Seasonal timing of first rain storms affects rare plant population dynamics

    Science.gov (United States)

    Levine, J.M.; McEachern, A.K.; Cowan, C.

    2011-01-01

    A major challenge in forecasting the ecological consequences of climate change is understanding the relative importance of changes to mean conditions vs. changes to discrete climatic events, such as storms, frosts, or droughts. Here we show that the first major storm of the growing season strongly influences the population dynamics of three rare and endangered annual plant species in a coastal California (USA) ecosystem. In a field experiment we used moisture barriers and water addition to manipulate the timing and temperature associated with first major rains of the season. The three focal species showed two- to fivefold variation in per capita population growth rates between the different storm treatments, comparable to variation found in a prior experiment imposing eightfold differences in season-long precipitation. Variation in germination was a major demographic driver of how two of three species responded to the first rains. For one of these species, the timing of the storm was the most critical determinant of its germination, while the other showed enhanced germination with colder storm temperatures. The role of temperature was further supported by laboratory trials showing enhanced germination in cooler treatments. Our work suggests that, because of species-specific cues for demographic transitions such as germination, changes to discrete climate events may be as, if not more, important than changes to season-long variables.

  11. A theoretical analysis of population genetics of plants on restored habitats

    Energy Technology Data Exchange (ETDEWEB)

    Bogoliubov, A.G. [Botanical Institute, Russian Academy of Science, St. Petersburg (Russian Federation); Loehle, C. [Argonne National Lab., IL (United States)

    1995-02-01

    Seed and propagules used for habitat restoration are not likely to be closely adapted to local site conditions. Rapid changes of genotypes frequencies on local microsites and/or microevolution would allow plants to become better adapted to a site. These same factors would help to maintain genetic diversity and ensure the survival of small endangered populations. We used population genetics models to examine the selection of genotypes during establishment on restored sites. Vegetative spread was shown to affect selection and significantly reduce genetic diversity. To study general microevolution, we linked a model of resource usage with a genetics model and analyzed competition between genotypes. A complex suite of feasible ecogenetic states was shown to result. The state actually resulting would depend strongly on initial conditions. This analysis indicated that genetic structure can vary locally and can produce overall genetic variability that is not simply the result of microsite adaptations. For restoration activities, the implication is that small differences in seed source could lead to large differences in local genetic structure after selection.

  12. A theoretical analysis of population genetics of plants on restored habitats

    Energy Technology Data Exchange (ETDEWEB)

    Bogoliubov, A.G. [Russian Academy of Science, St. Petersburg (Russian Federation). Botanical Inst.; Loehle, C. [Argonne National Lab., IL (United States). Environmental Research Div.

    1997-07-01

    Seed and propagules used for habitat restoration are not likely to be closely adapted to local site conditions. Rapid changes of genotypes frequencies on local microsites and/or microevolution would allow plants to become better adapted to a site. These same factors would help to maintain genetic diversity and ensure the survival of small endangered populations. The authors used population genetics models to examine the selection of genotypes during establishment on restored sites. Vegetative spread was shown to affect selection and significantly reduce genetic diversity. To study general microevolution, the authors linked a model of resource usage with a genetics model and analyzed competition between genotypes. A complex suite of feasible ecogenetic states was shown to result. The state actually resulting would depend strongly on initial conditions. This analysis indicated that genetic structure can vary locally and can produce overall genetic variability that is not simply the result of microsite adaptations. For restoration activities, the implication is that small differences in seed source could lead to large differences in local genetic structure after selection.

  13. Experimental Population Genetics in the Introductory Genetics Laboratory Using "Drosophila" as a Model Organism

    Science.gov (United States)

    Johnson, Ronald; Kennon, Tillman

    2009-01-01

    Hypotheses of population genetics are derived and tested by students in the introductory genetics laboratory classroom as they explore the effects of biotic variables (physical traits of fruit flies) and abiotic variables (island size and distance) on fruit fly populations. In addition to this hypothesis-driven experiment, the development of…

  14. Grand challenges in evolutionary and population genetics: The importance of integrating epigenetics, genomics, modeling, and experimentation

    Science.gov (United States)

    Samuel A. Cushman

    2014-01-01

    This is a time of explosive growth in the fields of evolutionary and population genetics, with whole genome sequencing and bioinformatics driving a transformative paradigm shift (Morozova and Marra, 2008). At the same time, advances in epigenetics are thoroughly transforming our understanding of evolutionary processes and their implications for populations, species and...

  15. Effects of experimental nitrogen additions on plant diversity in tropical forests of contrasting disturbance regimes in southern China

    International Nuclear Information System (INIS)

    Lu Xiankai; Mo Jiangming; Gilliam, Frank S.; Yu Guirui; Zhang Wei; Fang Yunting; Huang Juan

    2011-01-01

    Responses of understory plant diversity to nitrogen (N) additions were investigated in reforested forests of contrasting disturbance regimes in southern China from 2003 to 2008: disturbed forest (with harvesting of understory vegetation and litter) and rehabilitated forest (without harvesting). Experimental additions of N were administered as the following treatments: Control, 50 kg N ha -1 yr -1 , and 100 kg N ha -1 yr -1 . Nitrogen additions did not significantly affect understory plant richness, density, and cover in the disturbed forest. Similarly, no significant response was found for canopy closure in this forest. In the rehabilitated forest, species richness and density showed no significant response to N additions; however, understory cover decreased significantly in the N-treated plots, largely a function of a significant increase in canopy closure. Our results suggest that responses of plant diversity to N deposition may vary with different land-use history, and rehabilitated forests may be more sensitive to N deposition. - Highlights: → Nitrogen addition had no significant effect on understory plant diversity in the disturbed forest. → Nitrogen addition significantly decreased understory plant cover. → Nitrogen addition had no effect on richness and density in the rehabilitated forest. → The decrease is largely a function of a significant increase in canopy closure. → Land-use practices may dominate the responses of plant diversity to N addition. - Research in disturbed forests of southeastern China demonstrates that land-use history can substantially alter effects of excess nitrogen deposition on plant diversity of tropical forest ecosystems.

  16. Summary of experimental tests of elastomeric seismic isolation bearings for use in nuclear reactor plants

    International Nuclear Information System (INIS)

    Seidensticker, R.W.; Chang, Y.W.; Kulak, R.F.

    1992-01-01

    This paper describes an experimental test program for isolator bearings which was developed to help establish the viability of using laminated elastomer bearings for base isolation of nuclear reactor plants. The goal of the test program is to determine the performance characteristics of laminated seismic isolation bearings under a wide range of loadings. Tests were performed on scale-size laminated seismic isolators both within the design shear strain range to determine the response of the bearing under expected earthquake loading conditions, and beyond the design range to determine failure modes and to establish safety margins. Three types of bearings, each produced from a different manufacturer, have been tested: (1) high shape factor-high damping-high shear modulus bearings; (2) medium shape factor-high damping-high shear modulus bearings; and (3) medium shape factor-high damping-low shear modulus bearings. All of these tests described in this report were performed at the Earthquake Engineering Research Center at the University of California, Berkeley, with technical assistance from ANL. The tests performed on the three types of bearings have confirmed the high performance characteristics of the high damping-high and low shear modulus elastomeric bearings. The bearings have shown that they are capable of having extremely large shear strains before failure occurs. The most common failure mechanism was the debonding of the top steel plate from the isolators. This failure mechanism can be virtually eliminated by improved manufacturing quality control. The most important result of the failure test of the isolators is the fact that bearings can sustain large horizontal displacement, several times larger than the design value, with failure. Their performance in moderate and strong earthquakes will be far superior to conventional structures

  17. Off-gas treatment system Process Experimental Pilot Plant (PREPP) k-t evaluation

    International Nuclear Information System (INIS)

    Hedahl, T.G.; Cargo, C.H.; Ayers, A.L.

    1982-06-01

    The scope of work for this task involves a systems' evaluation, using the Kepner-Tregoe (K-T) decision analysis methodology, of off-gas treatment alternatives for a Process Experimental Pilot Plant (PREPP). Two basic systems were evaluated: (1) a wet treatment system using a quencher and scrubber system; and (2) a dry treatment system using a spray dryer and baghouse arrangement. Both systems would neutralize acidic off-gases (HCL and SO 2 ) and remove radioactive particulates prior to release to the environment. The K-T analysis results provided a numerical comparison of the two basic off-gas treatments systems for PREPP. The overall ratings for the two systems differ by only 7%. The closeness of the evaluation indicates that either system is capable of treating the off-gases from PREPP. Based on the analysis, the wet treatment system design is slightly more favorable for PREPP. Technology development, expected operability, total costs, and safety aspects were determined to be more advantageous for the wet system design. Support technology was the only major category that appears less favorable for using the wet off-gas system for PREPP. When considering the two criteria considered most important for PREPP (capital cost and major accident prevention - both rated 10), the wet treatment system received maximum ratings. Space constraints placed on the design by the existing TAN-607 building configuration also are more easily met by the wet system design. Lastly, the level of development for the wet system indicates more applicable experience for nuclear waste processing

  18. The structuring process of the macroparasite community of an experimental population of cichlasoma urophthalmus through time

    Science.gov (United States)

    Vidal-Martinez; Kennedy; Aguirre-Macedo

    1998-09-01

    The structuring process of the macroparasite community of caged Cichlasoma urophthalmus was studied over time using sentinel fish. Three thousand uninfected cichlids were stocked in floating cages introduced into a quarry in which a wild population of the same species was present. Caged and wild cichlids were sampled monthly over 6 and 7 months, respectively. Seventeen macroparasite species were found in the wild C. urophthalmus population, ten of which were detected in the caged population after 6 months. Early infections were by those species that were more frequent and abundant in the wild population, while helminths with a low prevalence and abundance in the wild appeared later in the caged fish population. The results suggested that the structuring process of the macroparasite community of caged C. urophthalmus followed a predictable pattern, in which those species that were most frequent and abundant in the wild were the first to establish in sentinel fish.

  19. Phylogeny, plant species, and plant diversity influence carbon use phenotypes among Fusarium populations in the rhizosphere microbiome

    Science.gov (United States)

    Carbon use by microorganisms in the rhizosphere microbiome has been linked to plant pathogen suppression and increased mineralization of soil nutrients for plant uptake, however factors that influence carbon use traits are poorly understood for most microbial groups. This work characterized the rela...

  20. Optimization of the process of methylic transesterification of palm oil an experimental plant in batches in RECOPE

    International Nuclear Information System (INIS)

    Delgado Quesada, Adrian

    2013-01-01

    The production process of biodiesel is optimized in the Laboratorio de Investigacion of RECOPE. A subprocess of raw material purification and finished product is implemented. Parameters of optimization for the experimental plant are established by a bibliographic search. Palm oil acquired by RECOPE is characterized. The optimization of the alkaline transesterification of palm oil with methanol is realized in the experimental plant of RECOPE, through a full factorial design of five variables on two levels: the effect of temperature, the relationship of catalyst-oil, the speed of agitation, the molar relationship alcohol-oil and the reaction time in the production of biodiesel. The operation optimal values of the experimental plant are obtained by ANOVA. The maximum quantity of soaps required is determined to saturate exchange resin used in the purification of the biodiesel. The parameters of optimum operating are proposed for the production process of methyl biodiesel of palm according to the conditions of the oil and in the test plant of RECOPE. The result of the analysis of control variables of the biodiesel as the density have been according to reported by the Reglamento Tecnico Centroamericano (RTCA). However, the measured variables to biodiesel as total glycerin, inflammability point, content of fatty acid methyl esters and acid number have indicated the necessity to implement pretreatment steps from the oil by acid esterification. Besides, the study has determined that biodiesel remains without comply with the standards established by the RTCA for its commercialization at national or international level [es

  1. Adaptive Potential for the Invasion of Novel Host Plants in the Bean Weevil: Patterns of the Reproductive Behavior in Populations That Used Different Host Plants

    Directory of Open Access Journals (Sweden)

    Dragana Milanović

    2007-01-01

    Full Text Available The goal of this work was to examine interpopulation patterns in the reproductive behavior of populations of bean weevil (Acanthoscelides obtectus Say; Coleoptera: Bruchidae that had different levels of specialization on their native host plant – the bean (Phaseolus vulgaris L., as well as on a novel host plant – the chickpea (Cicer arietinum Thorn. The obtained pattern of interpopulation mating behavior seemed exactly as if the males on chickpea had evolved a specific odor and/or a courtship ritual that females of populationson bean found repulsive. Unlike females, the males of bean populations seemed to be willing to mate with females from the population on chickpea equally as with their own females. Such an asymmetric pattern of reproductive isolation between populations ofa species has been often considered an initial phase of a process of speciation. Thus, our results could be a good starting point for further, thorough examination of both the role of the level of host specialization in females and the role of biochemical characteristics of male pheromone (and/or their cuticular hydrocarbones in the evolution of pre-reproductive isolation between insect populations.As the results of this study, together those of previous studies on A. obtectus, suggest great evolutionary potential for invasions of and fast specialization on novel host plants, they could provide valuable information for the development of long-term strategiesunder the programmes of Integrated Pest Management.

  2. Vector population growth and condition-dependent movement drive the spread of plant pathogens.

    Science.gov (United States)

    Shaw, Allison K; Peace, Angela; Power, Alison G; Bosque-Pérez, Nilsa A

    2017-08-01

    Plant viruses, often spread by arthropod vectors, impact natural and agricultural ecosystems worldwide. Intuitively, the movement behavior and life history of vectors influence pathogen spread, but the relative contribution of each factor has not been examined. Recent research has highlighted the influence of host infection status on vector behavior and life history. Here, we developed a model to explore how vector traits influence the spread of vector-borne plant viruses. We allowed vector life history (growth rate, carrying capacity) and movement behavior (departure and settlement rates) parameters to be conditional on whether the plant host is infected or healthy and whether the vector is viruliferous (carrying the virus) or not. We ran simulations under a wide range of parameter combinations and quantified the fraction of hosts infected over time. We also ran case studies of the model for Barley yellow dwarf virus, a persistently transmitted virus, and for Potato virus Y, a non-persistently transmitted virus. We quantified the relative importance of each parameter on pathogen spread using Latin hypercube sampling with the statistical partial rank correlation coefficient technique. We found two general types of mechanisms in our model that increased the rate of pathogen spread. First, increasing factors such as vector intrinsic growth rate, carrying capacity, and departure rate from hosts (independent of whether these factors were condition-dependent) led to more vectors moving between hosts, which increased pathogen spread. Second, changing condition-dependent factors such as a vector's preference for settling on a host with a different infection status than itself, and vector tendency to leave a host of the same infection status, led to increased contact between hosts and vectors with different infection statuses, which also increased pathogen spread. Overall, our findings suggest that vector population growth rates had the greatest influence on rates of virus

  3. [Using IRAP markers for analysis of genetic variability in populations of resource and rare species of plants].

    Science.gov (United States)

    Boronnikova, S V; Kalendar', R N

    2010-01-01

    Species-specific LTR retrotransposons were first cloned in five rare relic species of drug plants located in the Perm' region. Sequences of LTR retrotransposons were used for PCR analysis based on amplification of repeated sequences from LTR or other sites of retrotransposons (IRAP). Genetic diversity was studied in six populations of rare relic species of plants Adonis vernalis L. by means of the IRAP method; 125 polymorphic IRAP-markers were analyzed. Parameters for DNA polymorphism and genetic diversity of A. vernalis populations were determined.

  4. Evolution of apomixis loci in Pilosella and Hieracium (Asteraceae) inferred from the conservation of apomixis-linked markers in natural and experimental populations

    Science.gov (United States)

    Hand, M L; Vít, P; Krahulcová, A; Johnson, S D; Oelkers, K; Siddons, H; Chrtek, J; Fehrer, J; Koltunow, A M G

    2015-01-01

    The Hieracium and Pilosella (Lactuceae, Asteraceae) genera of closely related hawkweeds contain species with two different modes of gametophytic apomixis (asexual seed formation). Both genera contain polyploid species, and in wild populations, sexual and apomictic species co-exist. Apomixis is known to co-exist with sexuality in apomictic Pilosella individuals, however, apomictic Hieracium have been regarded as obligate apomicts. Here, a developmental analysis of apomixis within 16 Hieracium species revealed meiosis and megaspore tetrad formation in 1 to 7% of ovules, for the first time indicating residual sexuality in this genus. Molecular markers linked to the two independent, dominant loci LOSS OF APOMEIOSIS (LOA) and LOSS OF PARTHENOGENESIS (LOP) controlling apomixis in Pilosella piloselloides subsp. praealta were screened across 20 phenotyped Hieracium individuals from natural populations, and 65 phenotyped Pilosella individuals from natural and experimental cross populations, to examine their conservation, inheritance and association with reproductive modes. All of the tested LOA and LOP-linked markers were absent in the 20 Hieracium samples irrespective of their reproductive mode. Within Pilosella, LOA and LOP-linked markers were essentially absent within the sexual plants, although they were not conserved in all apomictic individuals. Both loci appeared to be inherited independently, and evidence for additional genetic factors influencing quantitative expression of LOA and LOP was obtained. Collectively, these data suggest independent evolution of apomixis in Hieracium and Pilosella and are discussed with respect to current knowledge of the evolution of apomixis. PMID:25026970

  5. Factors affecting the frequency of infection by the sigma virus in experimental populations of Drosophila melanogaster.

    Science.gov (United States)

    Fleuriet, A

    1982-01-01

    The experiments reported in this paper deal with the maintenance of the non contagious, hereditary virus sigma in populations of its host, Drosophila melanogaster. Evidence was previously provided of the existence of two viral Types I and II, depending on their sensitivity to the ref(2)Pp allele (the ref(2)P locus interferes with the multiplication of the virus in the fly). The viral Type I which is the most sensitive to the ref(2)Pp allele, is eliminated in the presence of this allele, even when most of the flies were originally infected in the population. On the contrary, the presence of the ref(2)Pp allele does not prevent a viral Type II, introduced in a population, from infecting most of the flies. The possibility that a change has occurred recently in French natural populations of Drosophila melanogaster is discussed.

  6. 76 FR 28715 - Endangered and Threatened Species: Designation of a Nonessential Experimental Population for...

    Science.gov (United States)

    2011-05-18

    ... Portal: http://www.regulations.gov . Follow the instructions for submitting comments. Mail: Submit... removal. In this case, the donor steelhead are from a captive bred population, which is propagated to... implementation of [[Page 28721

  7. A field experiment demonstrating plant life-history evolution and its eco-evolutionary feedback to seed predator populations.

    Science.gov (United States)

    Agrawal, Anurag A; Johnson, Marc T J; Hastings, Amy P; Maron, John L

    2013-05-01

    The extent to which evolutionary change occurs in a predictable manner under field conditions and how evolutionary changes feed back to influence ecological dynamics are fundamental, yet unresolved, questions. To address these issues, we established eight replicate populations of native common evening primrose (Oenothera biennis). Each population was planted with 18 genotypes in identical frequency. By tracking genotype frequencies with microsatellite DNA markers over the subsequent three years (up to three generations, ≈5,000 genotyped plants), we show rapid and consistent evolution of two heritable plant life-history traits (shorter life span and later flowering time). This rapid evolution was only partially the result of differential seed production; genotypic variation in seed germination also contributed to the observed evolutionary response. Since evening primrose genotypes exhibited heritable variation for resistance to insect herbivores, which was related to flowering time, we predicted that evolutionary changes in genotype frequencies would feed back to influence populations of a seed predator moth that specializes on O. biennis. By the conclusion of the experiment, variation in the genotypic composition among our eight replicate field populations was highly predictive of moth abundance. These results demonstrate how rapid evolution in field populations of a native plant can influence ecological interactions.

  8. Plant population and habitat characteristics of the endemic Sonoran Desert cactus Peniocereus striatus in Organ Pipe Cactus National Monument, Arizona

    Science.gov (United States)

    Anderson, Greta; Rutman, Sue; Munson, Seth M.

    2010-01-01

    Peniocereus striatus (Brandegee) Buxb. (Cactaceae) is an endemic Sonoran Desert cactus that reaches its northern range limit in southwestern Arizona. One U.S. population occupies a small area of Organ Pipe Cactus National Monument near the U.S./Mexico international boundary, which has been monitored since 1939. An extensive survey conducted in 2002, covering 177 ha, resulted in the discovery of 88 new plants, in addition to the relocation of 57 plants found in previous surveys. Despite potential increases in population size and spatial distribution, mean plant height and number of basal stems has not significantly changed in recent years. Bud scars revealed that a majority of the population was sexually mature. Peniocereus striatus occurrence increased with decreasing slope, spanned every slope aspect, and was highest on rocky soils, but was noticeably low on west and northwest slopes and areas where severe land degradation had previously occurred. Over half of P. striatus plants were nursed by shrubs and subshrubs, while 40% occurred under leguminous trees. A severe frost in January 2002 top-killed 19% of the population, with the greatest damage in drainage bottoms. However, long-term (1944–2002) climate records show that there has been an overall increase in the number of frost free days in the region, which, coupled with land use change, has implications for the future health of this population.

  9. Assessment of reproductive capacity of seeds sampled from natural populations of plants from a territory contaminated with radionuclides and heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Vakhusheva, O.; Evseeva, T. [Institute of biology Komi SC Ural Branch of RAS (Russian Federation)

    2014-07-01

    Plants are an essential component of any ecosystem and are permanently exposed to soil contamination. Therefore, they are widely used for characterization of ecological situation of the territory. Located at the base of the food chain, plants are exposed to toxic agents before the organisms at higher trophic levels. Kirovo-Chepetsk chemical plant (Kirov, Russia) is one of the biggest chemical enterprises in Europe. Vascular plant communities from surrounding area are exposed to industrial wastes, including uranium production wastes from 1938. The aim of this work was to estimate reproductive capacity of Urtica dioica L., Cirsium setosum (Willd.) Bess and Filipendula ulmaria (L.) Maxim - natural populations inhabiting the chemical plant industrial zone. The plant species studied are common for the meadow communities of south taiga zone, and are characterized by high seed yield and living in wide range of ecological conditions. Plant seeds were collected from two experimental sites with different soil contamination levels, located in the vicinity of the Kirovo-Chepetsk chemical plant, as well as from the reference site, in 2011 and 2012. Soil specific activities of {sup 137}Cs and {sup 90}Sr and concentrations of Ni, Pb, Cd, Zn, Hg and Cu were measured and ecological criteria of the radioactive (C{sub r}) and chemical (C{sub c}) contamination of the soil cover were calculated. Seeds germination, germinative energy and seedling survival rate were used for assessing reproductive capacity. Urtica dioicawas found to be the most sensitive among plant species studied. Germination of seeds from contaminated sites was significantly lower compared with the reference values. Exponential relationship was found between the levels of soil radioactive contamination and seeds germination (R{sup 2}=0.8, p<0.001). Germination of Cirsium setosum seeds, sampled from contaminated sites, exceeded the values obtained for the reference plant population and was linearly dependent (R{sup 2

  10. Parallel Genetic and Phenotypic Evolution of DNA Superhelicity in Experimental Populations of Escherichia coli

    DEFF Research Database (Denmark)

    Crozat, Estelle; Winkworth, Cynthia; Gaffé, Joël

    2010-01-01

    , indicate that changes in DNA superhelicity have been important in the evolution of these populations. Surprisingly, however, most of the evolved alleles we tested had either no detectable or slightly deleterious effects on fitness, despite these signatures of positive selection.......DNA supercoiling is the master function that interconnects chromosome structure and global gene transcription. This function has recently been shown to be under strong selection in Escherichia coli. During the evolution of 12 initially identical populations propagated in a defined environment...

  11. Genetic monitoring of experimental Drosophila populations exposed to X-radiation and treated with melanin

    International Nuclear Information System (INIS)

    Mosseh, I.B.; Savchenko, V.K.; Lyakh, I.P.

    1985-01-01

    Monitoring of laboratory populations of Drosophila over four years has demonstrated that X radiation of 0.25 C/kg, delivered during the life span of each generation, causes a decrease of 20% and 30%, on the average, in the number of individuals in 1-55 generations and 45-55 generations, respectively. The antimutagen, melanin, added to a nutrient medium has no effect on the number of individuals in populations

  12. Experimental Transmission of Pospiviroid Populations to Weed Species Characteristic of Potato and Hop Fields

    Czech Academy of Sciences Publication Activity Database

    Matoušek, Jaroslav; Orctová, Lidmila; Ptáček, J.; Patzak, J.; Dědič, P.; Steger, G.; Riesner, D.

    2007-01-01

    Roč. 81, č. 21 (2007), s. 11891-11899 ISSN 0022-538X R&D Projects: GA AV ČR(CZ) 1QS500510558 Institutional research plan: CEZ:AV0Z50510513 Keywords : plant virology * pospiviroid Subject RIV: EE - Microbiology, Virology Impact factor: 5.332, year: 2007

  13. Population growth and within-plant distribution of the striped mealybug Ferrisia virgata (Cockerell (Hemiptera, Pseudococcidae on cotton

    Directory of Open Access Journals (Sweden)

    Martin D. Oliveira

    2014-03-01

    Full Text Available Population growth and within-plant distribution of the striped mealybug Ferrisia virgata (Cockerell (Hemiptera, Pseudococcidae on cotton. The striped mealybug, Ferrisia virgata (Cockerell (Hemiptera, Pseudococcidae, is a widely distributed and polyphagous pest species, which naturally occurs on cotton plants in Brazil. This study evaluated the establishment and population growth as well as the within-plant distribution of F. virgata on four cotton cultivars: CNPA 7H (white fibers, BRS Verde, BRS Safira, and BRS Rubi (colored fibers. The experiment was conducted in a complete randomized design with four treatments (cultivars and 18 replications of each. Thus, cotton plants of each cultivar were infested with 100 newly hatched nymphs of F. virgata. The number of adult female mealybugs and the total number of mealybugs per plant were quantified, respectively, at 25 and 50 days after infestation. The developmental and pre-reproductive periods were also determined. Furthermore, we verified the distribution of F. virgata on the plant parts at 25 and 50 days after infestation. Ferrisia virgata showed similar growth of 412-fold in the four cotton cultivars studied. Also, the nymphs were spread on infested leaves; the secondgeneration nymphs were spread and established in all plant parts. Our results characterize F. virgata as having much potential as an important cotton pest in Brazil.

  14. Increased plant productivity in Alaskan tundra as a result of experimental warming of soil and permafrost

    Science.gov (United States)

    S.M. Natali; E.A.G. Schuur; R.L. Rubin

    2012-01-01

    The response of northern tundra plant communities to warming temperatures is of critical concern because permafrost ecosystems play a key role in global carbon (C) storage, and climate-induced ecological shifts in the plant community will affect the transfer of carbon-dioxide between biological and atmospheric pools. This study, which focuses on the response of tundra...

  15. Project Management Plan for the Idaho National Engineering Laboratory Waste Isolation Pilot Plant Experimental Test Program

    International Nuclear Information System (INIS)

    Connolly, M.J.; Sayer, D.L.

    1993-11-01

    EG ampersand G Idaho, Inc. and Argonne National Laboratory-West (ANL-W) are participating in the Idaho National Engineering Laboratory's (INEL's) Waste Isolation Pilot Plant (WIPP) Experimental Test Program (WETP). The purpose of the INEL WET is to provide chemical, physical, and radiochemical data on transuranic (TRU) waste to be stored at WIPP. The waste characterization data collected will be used to support the WIPP Performance Assessment (PA), development of the disposal No-Migration Variance Petition (NMVP), and to support the WIPP disposal decision. The PA is an analysis required by the Code of Federal Regulations (CFR), Title 40, Part 191 (40 CFR 191), which identifies the processes and events that may affect the disposal system (WIPP) and examines the effects of those processes and events on the performance of WIPP. A NMVP is required for the WIPP by 40 CFR 268 in order to dispose of land disposal restriction (LDR) mixed TRU waste in WIPP. It is anticipated that the detailed Resource Conservation and Recovery Act (RCRA) waste characterization data of all INEL retrievably-stored TRU waste to be stored in WIPP will be required for the NMVP. Waste characterization requirements for PA and RCRA may not necessarily be identical. Waste characterization requirements for the PA will be defined by Sandia National Laboratories. The requirements for RCRA are defined in 40 CFR 268, WIPP RCRA Part B Application Waste Analysis Plan (WAP), and WIPP Waste Characterization Program Plan (WWCP). This Project Management Plan (PMP) addresses only the characterization of the contact handled (CH) TRU waste at the INEL. This document will address all work in which EG ampersand G Idaho is responsible concerning the INEL WETP. Even though EG ampersand G Idaho has no responsibility for the work that ANL-W is performing, EG ampersand G Idaho will keep a current status and provide a project coordination effort with ANL-W to ensure that the INEL, as a whole, is effectively and

  16. Prospective environmental risk assessment of mixtures in wastewater treatment plant effluents - Theoretical considerations and experimental verification.

    Science.gov (United States)

    Coors, Anja; Vollmar, Pia; Sacher, Frank; Polleichtner, Christian; Hassold, Enken; Gildemeister, Daniela; Kühnen, Ute

    2018-04-14

    The aquatic environment is continually exposed to a complex mixture of chemicals, whereby effluents of wastewater treatment plants (WWTPs) are one key source. The aim of the present study was to investigate whether environmental risk assessments (ERAs) addressing individual substances are sufficiently protective for such coincidental mixtures. Based on a literature review of chemicals reported to occur in municipal WWTP effluents and mode-of-action considerations, four different types of mixtures were composed containing human pharmaceuticals, pesticides, and chemicals regulated under REACH. The experimentally determined chronic aquatic toxicity of these mixtures towards primary producers and the invertebrate Daphnia magna could be adequately predicted by the concept of concentration addition, with up to 5-fold overestimation and less than 3-fold underestimation of mixture toxicity. Effluents of a municipal WWTP had no impact on the predictability of mixture toxicity and showed no adverse effects on the test organisms. Predictive ERAs for the individual mixture components based on here derived predicted no effect concentrations (PNECs) and median measured concentrations in WWTP effluents (MC eff ) indicated no unacceptable risk for any of the individual chemicals, while MC eff /PNEC summation indicated a possible risk for multi-component mixtures. However, a refined mixture assessment based on the sum of toxic units at species level indicated no unacceptable risks, and allowed for a safety margin of more than factor 10, not taking into account any dilution of WWTP effluents by surface waters. Individual substances, namely climbazole, fenofibric acid and fluoxetine, were dominating the risks of the investigated mixtures, while added risk due to the mixture was found to be low with the risk quotient being increased by less than factor 2. Yet, uncertainty remains regarding chronic mixture toxicity in fish, which was not included in the present study. The number and

  17. The leaf angle distribution of natural plant populations: assessing the canopy with a novel software tool.

    Science.gov (United States)

    Müller-Linow, Mark; Pinto-Espinosa, Francisco; Scharr, Hanno; Rascher, Uwe

    2015-01-01

    Three-dimensional canopies form complex architectures with temporally and spatially changing leaf orientations. Variations in canopy structure are linked to canopy function and they occur within the scope of genetic variability as well as a reaction to environmental factors like light, water and nutrient supply, and stress. An important key measure to characterize these structural properties is the leaf angle distribution, which in turn requires knowledge on the 3-dimensional single leaf surface. Despite a large number of 3-d sensors and methods only a few systems are applicable for fast and routine measurements in plants and natural canopies. A suitable approach is stereo imaging, which combines depth and color information that allows for easy segmentation of green leaf material and the extraction of plant traits, such as leaf angle distribution. We developed a software package, which provides tools for the quantification of leaf surface properties within natural canopies via 3-d reconstruction from stereo images. Our approach includes a semi-automatic selection process of single leaves and different modes of surface characterization via polygon smoothing or surface model fitting. Based on the resulting surface meshes leaf angle statistics are computed on the whole-leaf level or from local derivations. We include a case study to demonstrate the functionality of our software. 48 images of small sugar beet populations (4 varieties) have been analyzed on the base of their leaf angle distribution in order to investigate seasonal, genotypic and fertilization effects on leaf angle distributions. We could show that leaf angle distributions change during the course of the season with all varieties having a comparable development. Additionally, different varieties had different leaf angle orientation that could be separated in principle component analysis. In contrast nitrogen treatment had no effect on leaf angles. We show that a stereo imaging setup together with the

  18. Genet-specific DNA methylation probabilities detected in a spatial epigenetic analysis of a clonal plant population.

    Directory of Open Access Journals (Sweden)

    Kiwako S Araki

    Full Text Available In sessile organisms such as plants, spatial genetic structures of populations show long-lasting patterns. These structures have been analyzed across diverse taxa to understand the processes that determine the genetic makeup of organismal populations. For many sessile organisms that mainly propagate via clonal spread, epigenetic status can vary between clonal individuals in the absence of genetic changes. However, fewer previous studies have explored the epigenetic properties in comparison to the genetic properties of natural plant populations. Here, we report the simultaneous evaluation of the spatial structure of genetic and epigenetic variation in a natural population of the clonal plant Cardamine leucantha. We applied a hierarchical Bayesian model to evaluate the effects of membership of a genet (a group of individuals clonally derived from a single seed and vegetation cover on the epigenetic variation between ramets (clonal plants that are physiologically independent individuals. We sampled 332 ramets in a 20 m × 20 m study plot that contained 137 genets (identified using eight SSR markers. We detected epigenetic variation in DNA methylation at 24 methylation-sensitive amplified fragment length polymorphism (MS-AFLP loci. There were significant genet effects at all 24 MS-AFLP loci in the distribution of subepiloci. Vegetation cover had no statistically significant effect on variation in the majority of MS-AFLP loci. The spatial aggregation of epigenetic variation is therefore largely explained by the aggregation of ramets that belong to the same genets. By applying hierarchical Bayesian analyses, we successfully identified a number of genet-specific changes in epigenetic status within a natural plant population in a complex context, where genotypes and environmental factors are unevenly distributed. This finding suggests that it requires further studies on the spatial epigenetic structure of natural populations of diverse organisms

  19. Genet-specific DNA methylation probabilities detected in a spatial epigenetic analysis of a clonal plant population.

    Science.gov (United States)

    Araki, Kiwako S; Kubo, Takuya; Kudoh, Hiroshi

    2017-01-01

    In sessile organisms such as plants, spatial genetic structures of populations show long-lasting patterns. These structures have been analyzed across diverse taxa to understand the processes that determine the genetic makeup of organismal populations. For many sessile organisms that mainly propagate via clonal spread, epigenetic status can vary between clonal individuals in the absence of genetic changes. However, fewer previous studies have explored the epigenetic properties in comparison to the genetic properties of natural plant populations. Here, we report the simultaneous evaluation of the spatial structure of genetic and epigenetic variation in a natural population of the clonal plant Cardamine leucantha. We applied a hierarchical Bayesian model to evaluate the effects of membership of a genet (a group of individuals clonally derived from a single seed) and vegetation cover on the epigenetic variation between ramets (clonal plants that are physiologically independent individuals). We sampled 332 ramets in a 20 m × 20 m study plot that contained 137 genets (identified using eight SSR markers). We detected epigenetic variation in DNA methylation at 24 methylation-sensitive amplified fragment length polymorphism (MS-AFLP) loci. There were significant genet effects at all 24 MS-AFLP loci in the distribution of subepiloci. Vegetation cover had no statistically significant effect on variation in the majority of MS-AFLP loci. The spatial aggregation of epigenetic variation is therefore largely explained by the aggregation of ramets that belong to the same genets. By applying hierarchical Bayesian analyses, we successfully identified a number of genet-specific changes in epigenetic status within a natural plant population in a complex context, where genotypes and environmental factors are unevenly distributed. This finding suggests that it requires further studies on the spatial epigenetic structure of natural populations of diverse organisms, particularly for

  20. Survey of population health in towns with nuclear and fossil fuel power plants

    International Nuclear Information System (INIS)

    Ivanov, E.; Shubik, V. M.

    2004-01-01

    Comparative assessment of population health in Sosnovy Bor with nuclear power plant and Kirovsk with fossil fuel power station was made for public and administration information. Both towns are located in Leningrad administrative region at 150 km distance from each other. In nuclear power town radiological situation was assessed as normal and in Kirovsk up to 1995 yr. with coal fuel, maximum permissible levels of suspended particle of sulfur oxide in atmosphere were exceeded in 6-9% of samples. After 1995 yr. the natural gas was used as fuel. Demographic data for 1991-2000 yrs indicate that mortality including infants mortality and stillborns was lower in Sosnovy Bor (NOS) then in Kirovsk (fossil fuel) and on average Leningrad administrative region. Birth rate and population growth was higher in Sosnovy Bor at the same time surprisingly the recorded morbidity was higher in Sosnovy Bor which might be explained by extensive medical supervision and improved diagnostics. However, cancer and tuberculosis morbidity was lower in Sosnovy Bor. In Kirovsk in 1997-2000 yrs. oncological morbidity was higher on average comparing to Leningrad administrative region. Oncological mortality in Sosnovy Bor in 1997-2000 yrs. was lower than in Kirovsk and Leningrad region Standardized annual mortality in Sosnovy Bor, Kirovsk and Leningrad administrative region was 128.3, 209.6 and 211.7 on 100 000 respectively. Health state of pregnant women, deliveries, new-born condition were all in normal range in Sosnovy Bor, contrary to higher increased abortion rate and pregnancy complications in Kirovsk. These findings need further studies. (Author)

  1. Survey of population health in towns with nuclear and fossil fuel power plants

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, E.; Shubik, V. M.

    2004-07-01

    Comparative assessment of population health in Sosnovy Bor with nuclear power plant and Kirovsk with fossil fuel power station was made for public and administration information. Both towns are located in Leningrad administrative region at 150 km distance from each other. In nuclear power town radiological situation was assessed as normal and in Kirovsk up to 1995 yr. with coal fuel, maximum permissible levels of suspended particle of sulfur oxide in atmosphere were exceeded in 6-9% of samples. After 1995 yr. the natural gas was used as fuel. Demographic data for 1991-2000 yrs indicate that mortality including infants mortality and stillborns was lower in Sosnovy Bor (NOS) then in Kirovsk (fossil fuel) and on average Leningrad administrative region. Birth rate and population growth was higher in Sosnovy Bor at the same time surprisingly the recorded morbidity was higher in Sosnovy Bor which might be explained by extensive medical supervision and improved diagnostics. However, cancer and tuberculosis morbidity was lower in Sosnovy Bor. In Kirovsk in 1997-2000 yrs. oncological morbidity was higher on average comparing to Leningrad administrative region. Oncological mortality in Sosnovy Bor in 1997-2000 yrs. was lower than in Kirovsk and Leningrad region Standardized annual mortality in Sosnovy Bor, Kirovsk and Leningrad administrative region was 128.3, 209.6 and 211.7 on 100 000 respectively. Health state of pregnant women, deliveries, new-born condition were all in normal range in Sosnovy Bor, contrary to higher increased abortion rate and pregnancy complications in Kirovsk. These findings need further studies. (Author)

  2. Effects of Flavonoid-rich Plant Extracts on Ruminal Methanogenesis, Microbial Populations and Fermentation Characteristics

    Directory of Open Access Journals (Sweden)

    Eun T. Kim

    2015-04-01

    Full Text Available The objective of this study was to evaluate the in vitro effects of flavonoid-rich plant extracts (PE on ruminal fermentation characteristics and methane emission by studying their effectiveness for methanogenesis in the rumen. A fistulated Holstein cow was used as a donor of rumen fluid. The PE (Punica granatum, Betula schmidtii, Ginkgo biloba, Camellia japonica, and Cudrania tricuspidata known to have high concentrations of flavonoid were added to an in vitro fermentation incubated with rumen fluid. Total gas production and microbial growth with all PE was higher than that of the control at 24 h incubation, while the methane emission was significantly lower (p<0.05 than that of the control. The decrease in methane accumulation relative to the control was 47.6%, 39.6%, 46.7%, 47.9%, and 48.8% for Punica, Betula, Ginkgo, Camellia, and Cudrania treatments, respectively. Ciliate populations were reduced by more than 60% in flavonoid-rich PE treatments. The Fibrobacter succinogenes diversity in all added flavonoid-rich PE was shown to increase, while the Ruminoccocus albus and R. flavefaciens populations in all PE decreased as compared with the control. In particular, the F. succinogenes community with the addition of Birch extract increased to a greater extent than that of others. In conclusion, the results of this study showed that flavonoid-rich PE decreased ruminal methane emission without adversely affecting ruminal fermentation characteristics in vitro in 24 h incubation time, suggesting that the flavonoid-rich PE have potential possibility as bio-active regulator for ruminants.

  3. A new model for the inference of population characteristics from experimental data using uncertainties

    International Nuclear Information System (INIS)

    Cofino, Wim P.; Stokkum, Ivo H.M. van; Steenwijk, Jaap van; Wells, David E.

    2005-01-01

    This paper extends a recent report on a model to establish population characteristics to include censored data. The theoretical background is given. The application given in this paper is limited to left-censored data, i.e. less than values, but the principles can also be adopted for other types of censored data. The model gives robust estimates of population characteristics for datasets with complicated underlying distributions including less than values of different magnitude and less than values exceeding the values of numerical data. The extended model is illustrated with simulated datasets, data from interlaboratory studies and temporal trend data on dissolved cadmium in the Rhine river. The calculations confirm that inclusion of left-censored values in the computation of population characteristics improves assessment procedures

  4. Experimental investigation and modelling of tritium washout by precipitation in the area of the nuclear power plant of Paks, Hungary

    International Nuclear Information System (INIS)

    Koello, Z.; Palcsu, L.; Major, Z.; Papp, L.; Molnar, M.; Ranga, T.; Dombovari, P.; Manga, L.

    2011-01-01

    Tritium occurs in nature in trace amounts, but its concentration is changing due to natural and artificial sources. Studies focusing on natural tritium have to take into account the effect of artificial sources. Also, the impact of tritium is an important issue in environmental protection, e.g. in connection with the emissions from nuclear power plants. The present work focuses on the rain washout of tritium emitted from the Paks nuclear power plant in Hungary. Rainwater collectors were placed around the plant and after a period of precipitation, rainwater was collected and analysed for tritium content. Samples were analysed using low-level liquid scintillation counting, with some also subject to the more accurate 3 He ingrowth method. The results clearly show the trace of the tritium plume emitted from the plant; however, values are only about one order of magnitude higher than environmental background levels. A washout model was devised to estimate the distribution of tritium around the plant. The model gives slightly higher concentrations than those measured in the field, but in general the agreement is satisfactory. The modelled values demonstrate that the effect of the plant on rainwater tritium levels is negligible over a distance of some kilometres. - Research highlights: →The rainwater around a nuclear power plant was collected with a special rainwater collector →The rainwater after a rain event was analysed for tritium with LSC and with the helium ingrowth method. →The trace of the tritium plume is clearly detectable in the rainwater. →The agreement between a reversible washout model and experimental data is satisfactory. →According to the model the tritium plume is hardly detectable over some kilometers from the plant

  5. Experimental investigation and modelling of tritium washout by precipitation in the area of the nuclear power plant of Paks, Hungary

    Energy Technology Data Exchange (ETDEWEB)

    Koello, Z., E-mail: kolloz42@gmail.co [Hertelendi Laboratory of Environmental Studies, Institute of Nuclear Research of the Hungarian Academy of Sciences, Bem ter 18/c, Debrecen 4026 (Hungary); Palcsu, L.; Major, Z.; Papp, L.; Molnar, M. [Hertelendi Laboratory of Environmental Studies, Institute of Nuclear Research of the Hungarian Academy of Sciences, Bem ter 18/c, Debrecen 4026 (Hungary); Ranga, T.; Dombovari, P.; Manga, L. [Department of Radiation Protection, Nuclear Power Plant of Paks, Paks (Hungary)

    2011-01-15

    Tritium occurs in nature in trace amounts, but its concentration is changing due to natural and artificial sources. Studies focusing on natural tritium have to take into account the effect of artificial sources. Also, the impact of tritium is an important issue in environmental protection, e.g. in connection with the emissions from nuclear power plants. The present work focuses on the rain washout of tritium emitted from the Paks nuclear power plant in Hungary. Rainwater collectors were placed around the plant and after a period of precipitation, rainwater was collected and analysed for tritium content. Samples were analysed using low-level liquid scintillation counting, with some also subject to the more accurate {sup 3}He ingrowth method. The results clearly show the trace of the tritium plume emitted from the plant; however, values are only about one order of magnitude higher than environmental background levels. A washout model was devised to estimate the distribution of tritium around the plant. The model gives slightly higher concentrations than those measured in the field, but in general the agreement is satisfactory. The modelled values demonstrate that the effect of the plant on rainwater tritium levels is negligible over a distance of some kilometres. - Research highlights: {yields}The rainwater around a nuclear power plant was collected with a special rainwater collector {yields}The rainwater after a rain event was analysed for tritium with LSC and with the helium ingrowth method. {yields}The trace of the tritium plume is clearly detectable in the rainwater. {yields}The agreement between a reversible washout model and experimental data is satisfactory. {yields}According to the model the tritium plume is hardly detectable over some kilometers from the plant

  6. Contribution of seagrass plants to CO2 capture in a tropical seagrass meadow under experimental disturbance.

    Science.gov (United States)

    Deyanova, Diana; Gullström, Martin; Lyimo, Liberatus D; Dahl, Martin; Hamisi, Mariam I; Mtolera, Matern S P; Björk, Mats

    2017-01-01

    Coastal vegetative habitats are known to be highly productive environments with a high ability to capture and store carbon. During disturbance this important function could be compromised as plant photosynthetic capacity, biomass, and/or growth are reduced. To evaluate effects of disturbance on CO2 capture in plants we performed a five-month manipulative experiment in a tropical seagrass (Thalassia hemprichii) meadow exposed to two intensity levels of shading and simulated grazing. We assessed CO2 capture potential (as net CO2 fixation) using areal productivity calculated from continuous measurements of diel photosynthetic rates, and estimates of plant morphology, biomass and productivity/respiration (P/R) ratios (from the literature). To better understand the plant capacity to coping with level of disturbance we also measured plant growth and resource allocation. We observed substantial reductions in seagrass areal productivity, biomass, and leaf area that together resulted in a negative daily carbon balance in the two shading treatments as well as in the high-intensity simulated grazing treatment. Additionally, based on the concentrations of soluble carbohydrates and starch in the rhizomes, we found that the main reserve sources for plant growth were reduced in all treatments except for the low-intensity simulated grazing treatment. If permanent, these combined adverse effects will reduce the plants' resilience and capacity to recover after disturbance. This might in turn have long-lasting and devastating effects on important ecosystem functions, including the carbon sequestration capacity of the seagrass system.

  7. EPR pilot study on the population of Stepnogorsk city living in the vicinity of a uranium processing plant

    Energy Technology Data Exchange (ETDEWEB)

    Zhumadilov, Kassym; Akilbekov, Abdirash; Morzabayev, Aidar [L.N. Gumilyov Eurasian National University, Astana (Kazakhstan); Ivannikov, Alexander; Stepanenko, Valeriy [Medical Radiological Research Center, Obninsk (Russian Federation); Abralina, Sholpan; Sadvokasova, Lyazzat; Rakhypbekov, Tolebay [Semey State Medical University, Semey (Kazakhstan); Hoshi, Masaharu [Hiroshima University, Research Institute for Radiation Biology and Medicine, Hiroshima (Japan)

    2015-03-15

    The aim of this pilot study was to evaluate possible doses in teeth received by workers of a uranium processing plant, in excess to the natural background dose. For this, the electron paramagnetic resonance dosimetry method was applied. Absorbed doses in teeth from the workers were compared with those measured in teeth from the Stepnogorsk city population and a control pool population from Astana city. The measured tooth samples were extracted according to medical indications. In total, 32 tooth enamel samples were analyzed, 5 from Astana city, Kazakhstan (control population), 21 from the residents of Stepnogorsk city (180 km from Astana city), and 6 from the workers of a uranium processing plant. The estimated doses in tooth enamel from the uranium processing plant workers were not significantly different to those measured in enamel from the control population. In teeth from the workers, the maximum dose in excess to background dose was 33 mGy. In two teeth from residents of Stepnogorsk city, however, somewhat larger doses were measured. The results of this pilot study encourage further investigations in an effort to receiving a final conclusion on the exposure situation of the uranium processing plant workers and the residents of Stepnogorsk city. (orig.)

  8. Current use of wild plants with edible underground storage organs in a rural population of Patagonia: between tradition and change.

    Science.gov (United States)

    Ochoa, Juan José; Ladio, Ana Haydee

    2015-09-25

    Edible plants with underground storage organs (USOs) are neglected resources. We studied the local ecological knowledge edible plants with (USOs) in rural populations of North-Patagonia in order to establish how people are utilizing these plants. Some aspect of corpus-praxis-cosmos complex associated to the local ecological knowledge was documented and discussed. In addition, variation in this ecological knowledge due to age, gender, family structure, ethnic self-determination was also evaluated. Semi-structured interviews were conducted with 51 inhabitants in order to study the relationship between the current use of plants with USOs and the age, sex, family group composition and ethnic self-identification of interviewees. In addition, the Cultural Importance Index for each species was calculated. The current richness of known species in these populations is a total of 9 plants. Plants with USOs tend to be used more frequently as the age of the interviewee increases. Women and men showed no differences in the average richness of species cited. The interviewees who share their homes with other generations use these plants more frequently than those who live alone. Our results indicate that the interviewees who identified themselves as belonging to the Mapuche people use these plants more frequently. For the Mapuche people, wild plants have constituted material and symbolic resources of great importance in their historical subsistence. In addition, they are currently being redefined as elements which present a connection with ancestral practices, produce a strong relationship with the 'land', and become markers which identify the 'natural' (historical) ways of their people; these are key elements in the current political processes of identity revaluation. This research is valuable to stimulate cultural revival and health promotion programs in the communities with their own local, cultural food.

  9. Mate Limitation in Fungal Plant Parasites Can Lead to Cyclic Epidemics in Perennial Host Populations.

    Science.gov (United States)

    Ravigné, Virginie; Lemesle, Valérie; Walter, Alicia; Mailleret, Ludovic; Hamelin, Frédéric M

    2017-03-01

    Fungal plant parasites represent a growing concern for biodiversity and food security. Most ascomycete species are capable of producing different types of infectious spores both asexually and sexually. Yet the contributions of both types of spores to epidemiological dynamics have still to been fully researched. Here we studied the effect of mate limitation in parasites which perform both sexual and asexual reproduction in the same host. Since mate limitation implies positive density dependence at low population density, we modeled the dynamics of such species with both density-dependent (sexual) and density-independent (asexual) transmission rates. A first simple SIR model incorporating these two types of transmission from the infected compartment, suggested that combining sexual and asexual spore production can generate persistently cyclic epidemics in a significant part of the parameter space. It was then confirmed that cyclic persistence could occur in realistic situations by parameterizing a more detailed model fitting the biology of the Black Sigatoka disease of banana, for which literature data are available. We discuss the implications of these results for research on and management of Sigatoka diseases of banana.

  10. Psidium guajava: A Single Plant for Multiple Health Problems of Rural Indian Population.

    Science.gov (United States)

    Daswani, Poonam G; Gholkar, Manasi S; Birdi, Tannaz J

    2017-01-01

    The rural population in India faces a number of health problems and often has to rely on local remedies. Psidium guajava Linn. (guava), a tropical plant which is used as food and medicine can be used by rural communities due to its several medicinal properties. A literature search was undertaken to gauge the rural health scenario in India and compile the available literature on guava so as to reflect its usage in the treatment of multiple health conditions prevalent in rural communities. Towards this, electronic databases such as Pubmed, Science Direct, google scholar were scanned. Information on clinical trials on guava was obtained from Cochrane Central Register of Controlled Trials and Clinicaltrial.gov. The literature survey revealed that guava possesses various medicinal properties which have been reported from across the globe in the form of ethnobotanical/ethnopharmacological surveys, laboratory investigations and clinical trials. Besides documenting the safety of guava, the available literature shows that guava is efficacious against the following conditions which rural communities would encounter. (a) Gastrointestinal infections; (b) Malaria; (c)Respiratory infections; (d) Oral/dental infections; (e) Skin infections; (f) Diabetes; (g) Cardiovascular/hypertension; (h) Cancer; (i) Malnutrition; (j) Women problems; (k) Pain; (l) Fever; (m) Liver problems; (n) Kidney problems. In addition, guava can also be useful for treatment of animals and explored for its commercial applications. In conclusion, popularization of guava, can have multiple applications for rural communities.

  11. Investment in constitutive immune function by north American elk experimentally maintained at two different population densities

    Science.gov (United States)

    Cynthia J. Downs; Kelley M. Stewart; Brian L. Dick; Daniel E Crocker

    2015-01-01

    Natural selection favors individuals that respond with effective and appropriate immune responses to macro or microparasites. Animals living in populations close to ecological carrying capacity experience increased intraspecific competition, and as a result are often in poor nutritional condition. Nutritional condition, in turn, affects the amount of endogenous...

  12. 78 FR 2893 - Endangered and Threatened Species: Designation of a Nonessential Experimental Population for...

    Science.gov (United States)

    2013-01-15

    .... mykiss exhibits perhaps the most complex suite of life history traits of any species of Pacific salmonid... functions that support the viability of populations and their primary life history strategies throughout... conservation measures in a time certain fashion versus the potential for some harm and determined that, on...

  13. Experimental evidence for convergent evolution of maternal care heuristics in industrialized and small-scale populations.

    Science.gov (United States)

    Kushnick, Geoff; Hanowell, Ben; Kim, Jun-Hong; Langstieh, Banrida; Magnano, Vittorio; Oláh, Katalin

    2015-06-01

    Maternal care decision rules should evolve responsiveness to factors impinging on the fitness pay-offs of care. Because the caretaking environments common in industrialized and small-scale societies vary in predictable ways, we hypothesize that heuristics guiding maternal behaviour will also differ between these two types of populations. We used a factorial vignette experiment to elicit third-party judgements about likely caretaking decisions of a hypothetical mother and her child when various fitness-relevant factors (maternal age and access to resources, and offspring age, sex and quality) were varied systematically in seven populations-three industrialized and four small-scale. Despite considerable variation in responses, we found that three of five main effects, and the two severity effects, exhibited statistically significant industrialized/ small-scale population differences. All differences could be explained as adaptive solutions to industrialized versus small-scale caretaking environments. Further, we found gradients in the relationship between the population-specific estimates and national-level socio-economic indicators, further implicating important aspects of the variation in industrialized and small-scale caretaking environments in shaping heuristics. Although there is mounting evidence for a genetic component to human maternal behaviour, there is no current evidence for interpopulation variation in candidate genes. We nonetheless suggest that heuristics guiding maternal behaviour in diverse societies emerge via convergent evolution in response to similar selective pressures.

  14. Measuring inequity aversion in a heterogeneous population using experimental decisions and subjective probabilities

    NARCIS (Netherlands)

    Bellemare, C.; Kroger, S.; van Soest, A.H.O.

    2008-01-01

    We combine choice data in the ultimatum game with the expectations of proposers elicited by subjective probability questions to estimate a structural model of decision making under uncertainty. The model, estimated using a large representative sample of subjects from the Dutch population, allows

  15. 78 FR 79622 - Endangered and Threatened Species: Designation of a Nonessential Experimental Population of...

    Science.gov (United States)

    2013-12-31

    ... identifying fish that are reintroduced, such as marking fish with specific fin clips (e.g., coded-wire tags... population area that have intact adipose fins as well as those that are adipose fin-clipped. In addition, the... thereby impact water supply. NMFS will develop a technical memorandum (tech memo) annually containing a...

  16. Experimental study of relative level populations in beam-foil excited Ar+7 and Kr+7

    International Nuclear Information System (INIS)

    Bashkin, S.; Oona, H.; Veje, E.

    1981-01-01

    The relative level populations in beam-foil excited sodium-like argon (Ar VIII) and copper-like krypton (Kr VIII) have been studied at 2 MeV projectile energy. In Ar VIII, the 3p and the 3d terms are strongly excited. The level population decreases rapidly with increasing value of the principal quantum number n, reaches a minimum for levels with n = 5 or 6, but increases then and reaches a strong maximum for levels with n approximately 11. Also the Kr VIII data show a population maximum for levels with n = 11. The strong 3p and 3d level excitations in Ar VIII are explained as selective inner-shell processes which can be understood in the molecular-orbital electron-promotion picture. The preferential population of high-flying Rydberg states is explained as resulting from a near-resonance electron transfer from the valence band of the carbon foil to the projectile. This process takes place when the projectile leaves the back of the foil. (Auth.)

  17. Experimental evaluation of admission and disposition of artificial radionuclides including transuranium elements in agricultural plants

    Energy Technology Data Exchange (ETDEWEB)

    Kozhakhanov, T.; Lukashenko, S. [Institute of radiation safety and ecology (Kazakhstan)

    2014-07-01

    Processes of radionuclides migration and transfer to agricultural plants are quite well developed worldwide, but the information on character of accumulation of {sup 241}Am and {sup 239+240}Pu transuranium radionuclides in agricultural plants is still fragmentary. Even in generalized materials of worldwide studies, IAEA guide, accumulation coefficient (AC) can have wide range of values (5-6 orders), no data exists on radionuclides' distribution in different organs of plants and they are given for joined groups of plants and types of soils. That is why the main aim of this work was to obtain basic quantitative parameters of radionuclides' migration in 'soil-plant' system, and firs of all- for transuranium elements.. In 2010 a series of experiments with agricultural plants was started at the territory of the former Semipalatinsk Test Site aimed to investigate entry of artificial radionuclides by crop products in natural climatic conditions. To conduct the experiment for study of coefficient of radionuclides' accumulation by agricultural corps, there was chosen a land spot at the STS territory, characterized by high concentration of radionuclides: {sup 241}Am - n*10{sup 4} Bq/kg, {sup 137}Cs - n*10{sup 3} Bq/kg, {sup 90}Sr - n*10{sup 3} Bq/kg and {sup 239+240}Pu- n*10{sup 5} Bq/kg. As objects of investigation, cultures, cultivated in Kazakhstan have been selected: wheat (Triticum vulgare), barley (Hordeum vulgare), oat (Avena sativa L.), water melon (Citrullus vulgaris), melon (Cucumis melo), potato (Solanum tuberosum), eggplant (Solanum melongena), pepper (Capsicum annuum), tomato (Solanum lycopersicum), sunflower (Helianthus cultus), onion (Allium cepa), carrot (Daucus carota), parsley(Petroselinum vulgare)and cabbage (Brassica oleracea). Investigated plants have been planted within the time limits, recommended for selected types of agricultural plants. Cropping system included simple agronomic and amelioration measures. Fertilizers were not

  18. Plant species diversity affects infiltration capacity in an experimental grassland through changes in soil properties

    NARCIS (Netherlands)

    Fischer, C.; Tischer, J.; Roscher, C.; Eisenhauer, N.; Ravenek, J.; Gleixner, G.; Attinger, S.; Jensen, B.; Kroon, de H.; Mommer, L.; Scheu, S.; Hildebrandt, A.

    2015-01-01

    Background and aims Soil hydraulic properties drive water distribution and availability in soil. There exists limited knowledge of how plant species diversity might influence soil hydraulic properties. Methods We quantified the change in infiltration capacity affected by soil structural variables

  19. An analytical and experimental study of the behaviour of redundant controllers applied to a nuclear plant

    International Nuclear Information System (INIS)

    Lawrence, L.A.J.

    1964-02-01

    The behaviour of a number of configurations of redundant controllers is examined and the design problems discussed in relation to the engineering of reliable control rod drive systems for nuclear plant. (author)

  20. Reproductive allocation strategies in desert and Mediterranean populations of annual plants grown with and without water stress.

    Science.gov (United States)

    Aronson, J; Kigel, J; Shmida, A

    1993-03-01

    Reproductive effort (relative allocation of biomass to diaspore production) was compared in matched pairs of Mediterranean and desert populations of three unrelated annual species, Erucaria hispanica (L.) Druce, Bromus fasciculatus C. Presl. and Brachypodium distachyon (L.) Beauv., grown under high and low levels of water availability in a common-environment experiment. Desert populations in all three species showed higher reproductive effort than corresponding Mediterranean populations, as expressed by both a reproductive index (RI= reproductive biomass/vegetative biomass), and a reproductive efficiency index (REI=number of diaspores/total plant biomass). Moreover, in E. hispanica and Brachypodium distachyon, inter-populational differences in reproductive effort were greater under water stress, the main limiting factor for plant growth in the desert. These results indicate that variability in reproductive effort in response to drought is a critical and dynamic component of life history strategies in annual species in heterogeneous, unpredictable xeric environments. When subjected to water stress the Mediterranean populations of E. hispanica and B. distachyon showed greater plasticity (e.g. had a greater reduction) in reproductive effort than the desert populations, while in Bromus fasciculatus both populations showed similar amounts of plasticity.

  1. Experimental Studies of Laser-Induced Fluorescence Spectra of Plants Immunity to the Kind of Ground

    Directory of Open Access Journals (Sweden)

    Yu. V. Fedotov

    2015-01-01

    Full Text Available Various external factors (pollutants available in the soil, a lack or insufficient amount of water and nutrients, etc. lead to stressful conditions of plants and impossibility of their normal development. At the early stages it is difficult to identify visually the stressful situations of plants. Therefore development of methods and devices to detect stressful states is important.A method of the laser-induced fluorescence is one of perspective methods for detection of stressful conditions of plants.In spite of quite a great number of work presenting results of the pilot studies of fluorescence spectra of vegetation, there are some important issues, which are unclear.The paper gives results of pilot studies of stability of a spectrum form of the laser-induced fluorescence of plants for different types of soil at the wavelength of excitation fluorescence of 532 nm.Results of processing fluorescence spectra of plants show:- fluorescence spectra of plants grown up under similar conditions have good repeatability of a spectra form for different samples of plants and different measurement time for each type of studied soil. The ratio value R of the fluorescence intensity at the wavelength of 685 nm to the fluorescence intensity at the wavelength of 740 nm has high stability. The standard deviation in sampling of the ratio R of different samples of a plant for one type of soil (for width of spectral ranges of recording fluorescent radiation of 10 nm lies in the range ~ 0.055 - ~ 0.12;- a difference in plant fluorescence spectra between themselves for different types of soil has the same order as a difference in fluorescence spectra of different samples of a plant for one type of soil. Difference in average value of the ratio R for different types of soil lies in the range ~ 0.01 - ~ 0.15.Thus, the value of the ratio R is steady against a type of soil and can be used to control a condition of plants.

  2. Pseudohypericin and Hyperforin in Hypericum perforatum from Northern Turkey: Variation among Populations, Plant Parts and Phenological Stages

    Institute of Scientific and Technical Information of China (English)

    Cüneyt ?irak; Jolita Radusiene; Valdimaras Janulis; Liudas Ivanauskas

    2008-01-01

    Hypericum perforatum is a perennial medicinal plant known as "St. John's wort" in Western Europe and has been used in the treatment of several diseases for centuries. In the present study, morphologic, phenologic and population variability in pseudohypericin and hyperforin concentrations among H. perforatum populations from Northern Turkey was investigated for the first time. The aerial parts of H. perforatum plants representing a total of 30 individuals were collected at full flowering from 10 sites of Northern Turkey to search the regional variation in the secondary metabolits concentrations. For morphologic and phenologic sampling, plants from one site were gathered in five phenological stages: vegetative,floral budding, full flowering, fresh fruiting and mature fruiting. The plant materials were air-dried at room temperature and subsequently assayed for chemical concentrations by high performance liquid chromatography. Secondary metabolite concentrations ranged from traces to 2.94mg/g dry weight (DW) for pseudohypedcin and traces -6.29mg/g DW for hyperforin. The differences in the secondary metabolite concentrations among populations of H. perforatum were found to be significant. The populations varied greatly in hyperforin concentrations, whereas they produced a similar amount of pseudohypericin. Concentrations of both secondary metabolites in all tissues increased with advancing of plant development and higher accumulation levels were reached at flowering. Among different tissues, full opened flowers were found to be superior to stems, leaves and the other reproductive parts with regard to pseudohypericin and hyperforin accumulations. The present findings might be useful to optimize the processing methodology of wild-harvested plant material and obtain Increased concentrations of these secondary metabolites.

  3. The Influence of Host Plant Extrafloral Nectaries on Multitrophic Interactions: An Experimental Investigation.

    Directory of Open Access Journals (Sweden)

    Suzanne Koptur

    Full Text Available A field experiment was conducted with outplantings of the native perennial shrub Senna mexicana var. chapmanii in a semi-natural area adjacent to native pine rockland habitat in southern Florida. The presence of ants and the availability of extrafloral nectar were manipulated in a stratified random design. Insect communities were monitored and recorded over a period of six months with a view to addressing three main questions. Do ants provide biotic defense against key herbivores on S. chapmanii? Is the presence of ants on S. chapmanii mediated by EFN? Finally, are there ecological costs associated with the presence of ants on S. chapmanii, such as a reduction in alternative predator or parasitoid numbers? Herbivores on S. chapmanii included immature stages of three pierid butterflies, and adult weevils. Eight species of ants were associated with the plants, and other predators included spiders, ladybugs, wasps, and hemipterans. Parasitic, haemolymph-sucking midges (Ceratopogonidae and parasitoid flies were also associated with the caterpillar herbivores, and possibly the extrafloral nectaries of the plants. The presence of ants did not appear to influence oviposition by butterflies, as numbers of lepidopterans of all developmental stages did not differ among treatments. Significantly more late instar caterpillars, however, were observed on plants with ants excluded, indicating that ants remove small caterpillars from plants. Substantially more alternative predators (spiders, ladybugs, and wasps were observed on plants with ants excluded. Rates of parasitization did not differ among the treatments, but there were substantially fewer caterpillars succumbing to virus among those collected from control plants. We provide a rare look at facultative ant-plant mutualisms in the context of the many other interactions with which they overlap. We conclude that ants provide some biotic defense against herbivores on S. chapmanii, and plants benefit overall

  4. Gardening in the zone of death: an experimental assessment of the absolute elevation limit of vascular plants.

    Science.gov (United States)

    Dvorský, Miroslav; Chlumská, Zuzana; Altman, Jan; Čapková, Kateřina; Řeháková, Klára; Macek, Martin; Kopecký, Martin; Liancourt, Pierre; Doležal, Jiří

    2016-04-13

    Vascular plants in the western Tibetan Plateau reach 6000 m--the highest elevation on Earth. Due to the significant warming of the region, plant ranges are expected to shift upwards. However, factors governing maximum elevational limits of plant are unclear. To experimentally assess these factors, we transplanted 12 species from 5750 m to 5900 m (upper edge of vegetation) and 6100 m (beyond range) and monitored their survival for six years. In the first three years (2009-2012), there were plants surviving beyond the regional upper limit of vegetation. This supports the hypothesis of dispersal and/or recruitment limitation. Substantial warming, recorded in-situ during this period, very likely facilitated the survival. The survival was ecologically a non-random process, species better adapted to repeated soil freezing and thawing survived significantly better. No species have survived at 6100 m since 2013, probably due to the extreme snowfall in 2013. In conclusion, apart from the minimum heat requirements, our results show that episodic climatic events are decisive determinants of upper elevational limits of vascular plants.

  5. Effect of plant population density on the growth and yield of sorghum ...

    African Journals Online (AJOL)

    Improvement of resource use efficiency and yields is probably possible through the use of appropriate plant densities. Field trials were therefore conducted to study the effects of four plant densities, varying from 2.0 to 12.5 plants m-2 on water and radiation use and performance of two Masakwa sorghum varieties grown on ...

  6. Using functional-structural plant modeling to explore the response of cotton to mepiquat chloride application and plant population density

    NARCIS (Netherlands)

    Gu, S.; Evers, J.B.; Zhang, L.; Mao, L.; Vos, J.; Li, Z.

    2013-01-01

    The crop growth regulator Mepiquat Chloride (MC) is widely used in cotton production to optimize the canopy structure in order to maximize the yield and fiber quality. Cotton plasticity in relation to MC and other agronomical practice was quantified using a functional-structural plant model of

  7. How TK-TD and population models for aquatic macrophytes could support the risk assessment for plant protection products.

    Science.gov (United States)

    Hommen, Udo; Schmitt, Walter; Heine, Simon; Brock, Theo Cm; Duquesne, Sabine; Manson, Phil; Meregalli, Giovanna; Ochoa-Acuña, Hugo; van Vliet, Peter; Arts, Gertie

    2016-01-01

    This case study of the Society of Environmental Toxicology and Chemistry (SETAC) workshop MODELINK demonstrates the potential use of mechanistic effects models for macrophytes to extrapolate from effects of a plant protection product observed in laboratory tests to effects resulting from dynamic exposure on macrophyte populations in edge-of-field water bodies. A standard European Union (EU) risk assessment for an example herbicide based on macrophyte laboratory tests indicated risks for several exposure scenarios. Three of these scenarios are further analyzed using effect models for 2 aquatic macrophytes, the free-floating standard test species Lemna sp., and the sediment-rooted submerged additional standard test species Myriophyllum spicatum. Both models include a toxicokinetic (TK) part, describing uptake and elimination of the toxicant, a toxicodynamic (TD) part, describing the internal concentration-response function for growth inhibition, and a description of biomass growth as a function of environmental factors to allow simulating seasonal dynamics. The TK-TD models are calibrated and tested using laboratory tests, whereas the growth models were assumed to be fit for purpose based on comparisons of predictions with typical growth patterns observed in the field. For the risk assessment, biomass dynamics are predicted for the control situation and for several exposure levels. Based on specific protection goals for macrophytes, preliminary example decision criteria are suggested for evaluating the model outputs. The models refined the risk indicated by lower tier testing for 2 exposure scenarios, while confirming the risk associated for the third. Uncertainties related to the experimental and the modeling approaches and their application in the risk assessment are discussed. Based on this case study and the assumption that the models prove suitable for risk assessment once fully evaluated, we recommend that 1) ecological scenarios be developed that are also

  8. Plant-plant interactions mediate the plastic and genotypic response of Plantago asiatica to CO2: an experiment with plant populations from naturally high CO2 areas.

    Science.gov (United States)

    van Loon, Marloes P; Rietkerk, Max; Dekker, Stefan C; Hikosaka, Kouki; Ueda, Miki U; Anten, Niels P R

    2016-06-01

    The rising atmospheric CO2 concentration ([CO2]) is a ubiquitous selective force that may strongly impact species distribution and vegetation functioning. Plant-plant interactions could mediate the trajectory of vegetation responses to elevated [CO2], because some plants may benefit more from [CO2] elevation than others. The relative contribution of plastic (within the plant's lifetime) and genotypic (over several generations) responses to elevated [CO2] on plant performance was investigated and how these patterns are modified by plant-plant interactions was analysed. Plantago asiatica seeds originating from natural CO2 springs and from ambient [CO2] sites were grown in mono stands of each one of the two origins as well as mixtures of both origins. In total, 1944 plants were grown in [CO2]-controlled walk-in climate rooms, under a [CO2] of 270, 450 and 750 ppm. A model was used for upscaling from leaf to whole-plant photosynthesis and for quantifying the influence of plastic and genotypic responses. It was shown that changes in canopy photosynthesis, specific leaf area (SLA) and stomatal conductance in response to changes in growth [CO2] were mainly determined by plastic and not by genotypic responses. We further found that plants originating from high [CO2] habitats performed better in terms of whole-plant photosynthesis, biomass and leaf area, than those from ambient [CO2] habitats at elevated [CO2] only when both genotypes competed. Similarly, plants from ambient [CO2] habitats performed better at low [CO2], also only when both genotypes competed. No difference in performance was found in mono stands. The results indicate that natural selection under increasing [CO2] will be mainly driven by competitive interactions. This supports the notion that plant-plant interactions have an important influence on future vegetation functioning and species distribution. Furthermore, plant performance was mainly driven by plastic and not by genotypic responses to changes in

  9. Mesocosm-Scale Experimental Quantification of Plant-Fungi Associations on Carbon Fluxes and Mineral Weathering

    Science.gov (United States)

    Andrews, M. Y.; Palmer, B.; Leake, J. R.; Banwart, S. A.; Beerling, D. J.

    2009-12-01

    The rise of land plants in the Paleozoic is classically implicated as driving lower atmospheric CO2 levels through enhanced weathering of Ca and Mg bearing silicate minerals. However, this view overlooks the fact that plants coevolved with associated mycorrhizal fungi over this time, with many of the weathering processes usually ascribed to plants actually being driven by the combined activities of roots and mycorrhizal fungi. Here we present initial results from a novel mesocosm-scale laboratory experiment designed to allow investigation of plant-driven carbon flux and mineral weathering at different soil depths under ambient (400 ppm) and elevated (1500 ppm) atmospheric CO2. Four species of plants were chosen to address evolutionary trends in symbiotic mycorrhizal association and rooting depth on biologically driven silicate weathering under the different CO2 regimes. Gymnosperms were used to investigate potential differences in weathering capabilities of two fungal symbioses: Sequoia sempervirens and Metasequoia glyptostroboides (arbuscular mycorrhizal, AM) and Pinus sylvestris (ectomycorrhizal, EM), and the shallow rooted ancient fern, Osmunda regalis, used to provide a contrast to the three more deeply rooted trees. Plants were grown in a cylindrical mesocosm with four horizontal inserts at each depth. These inserts are a mesh-covered dual-core unit whereby an inner core containing silicate minerals can be rotated within an outer core. The mesh excludes roots from the cylinders allowing fungal-rock pairings to be examined at each depth. Each core contains either basalt or granite, each with severed (rotated cores) or intact (static cores) mycorrhizae. This system provides a unique opportunity to examine the ability of a plant to weather minerals with and without its symbiotic fungi. Preliminary results indicate marked differences in nutritional and water requirements, and response to elevated CO2 between the species. The bulk solution chemistries (p

  10. Fluoride emanations from fatories: experimental study of the action of fluorine plants

    Energy Technology Data Exchange (ETDEWEB)

    Cristiani, H; Gautier, R

    1925-01-01

    Research work from 1883 onward and the author's own experiments on the damages done to plants by fluoric emanations from aluminum and/or chemical fertilizer factories are reviewed. Fluoric compounds may act through the soil and water that feed the plants, or directly on the plant organs exposed to fluorine-polluted air. Of the various toxic gases, hydrofluoric acid is the most noxious since it forms thick fogs with the humidity in the air. The effects are cumulative and may not become visible before repeated exposure of the plants to the gases. The toxic action of NaF derives from its ability to precipitate lime and to attach itself to other substances, such as proteins. Also, fluorine salts have antiseptic action on unicellular elements, and this has had practical applications. At the doses utilized, alkaline salts of fluorine do not precipitate albumin, and can hamper microbial growth. On the other hand, examination of plant lesions enables the detection of their fluoric, as opposed to other (sulfur, chlorine) origin. Stoklasa claims that the amount of emanation and smoke has increased 100-fold in the last century, reducing the crops in some regions by 30 to 90%. The work on fodder from industrial areas was confirmed by experiments with fluorine compounds in air and in water.

  11. Plant-plant interactions mediate the plastic and genotypic response of Plantago asiatica to CO2 : an experiment with plant populations from naturally high CO2 areas

    NARCIS (Netherlands)

    van Loon, Marloes P; Rietkerk, Max; Dekker, Stefan C; Hikosaka, Kouki; Ueda, Miki U; Anten, Niels P R

    2016-01-01

    Background and Aims The rising atmospheric CO2 concentration ([CO2]) is a ubiquitous selective force that may strongly impact species distribution and vegetation functioning. Plant–plant interactions could mediate the trajectory of vegetation responses to elevated [CO2], because some plants may

  12. Thorium base fuels reprocessing at the L.P.R. (Radiochemical Processes Laboratory) experimental plant

    International Nuclear Information System (INIS)

    Almagro, J.C.; Dupetit, G.A.; Deandreis, R.A.

    1987-01-01

    The availability of the LPR (Radiochemical Processes Laboratory) plant offers the possibility to demonstrate and create the necessary technological basis for thorium fuels reprocessing. To this purpose, the solvents extraction technique is used, employing TBP (at 30%) as solvent. The process is named THOREX, a one-cycle acid, which permits an adequate separation of Th 232 and U 233 components and fission products. For thorium oxide elements dissolution, the 'chopp-leach' process (installed at LPR) is used, employing a NO 3 H 13N, 0.05M FH and 0.1M Al (NO 3 ) 3 , as solvent. To adapt the pilot plant to the flow-sheet requirements proposed, minor modifications must be carried out in the interconnection of the existing decanting mixers. The input of the plant has been calculated by Origin Code modified for irradiations in reactors of the HWR type. (Author)

  13. Design study of plant system for the fusion experimental reactor (FER)

    International Nuclear Information System (INIS)

    Iida, Hiromasa; Kuroda, Hideo; Yamada, Masao; Suzuki, Tatsushi; Honda, Tsutomu; Ohmura, Hiroshi; Itoh, Shinichi.

    1986-11-01

    This report describes design study results of the FER plant system. The purpose of this study is to have an image of the FER plant system as a whole by designing major auxiliary systems, reactor building and maintenance and radwaste desposal systems. The major auxiliary systems include tritium, cooling, evacuation and fueling systems. For these each systems, flowdiagrams are studied and designs of devices and pipings are conducted. In the reactor building design, layout of the above auxiliary systems in the building is studied with careful zoning concept by the radiation level. Structural integrity of the reactor building is also studied including seismic analysis. In the design of the maintenance and radwaste system flowdiagram of failed reactor components is developed and transfer vehicles and buildings are designed. Finally assuming JAERI Naka site as the reactor site layout of the whole FER plant system is developed. (author)

  14. Selection of construction materials for equipment in an experimental reprocessing plant

    International Nuclear Information System (INIS)

    Mizrahi, R.; Cragnolino, G.A.

    1994-01-01

    A review is made of the most significant corrosion problems that may be present in different stages of the process in a spent fuel reprocessing plant. The influence of different variables is analyzed: concentration of nitric acid and other oxidizing species, temperature, etc., in corrosion of materials of most frequent use in pipings and equipment. The materials are austenitic stainless steels and refractory metals, especially zirconium and its alloys. Both general and localized corrosion phenomena are analyzed for these materials. Selection criteria for the use of adequate material in different components of the plant are also discussed. (author). 32 refs., 20 figs., 3 tabs

  15. Population densities of indigenous Acidobacteria change in the presence of plant growth promoting rhizobacteria (PGPR) in rhizosphere.

    Science.gov (United States)

    Kalam, Sadaf; Das, Subha Narayan; Basu, Anirban; Podile, Appa Rao

    2017-05-01

    Rhizosphere microbial community has diverse metabolic capabilities and plays a crucial role in maintaining plant health. Oligotrophic plant growth promoting rhizobacteria (PGPR), along with difficult-to-culture microbial fractions, might be involved synergistically in microbe-microbe and plant-microbe interactions in the rhizosphere. Among the difficult-to-culture microbial fractions, Acidobacteria constitutes the most dominant phylum thriving in rhizospheric soils. We selected effective PGPR for tomato and black gram and studied their effect on population densities of acidobacterial members. Three facultatively oligotrophic PGPR were identified through 16S rRNA gene sequencing as Sphingobacterium sp. (P3), Variovorax sp. (P4), and Roseomonas sp. (A2); the latter being a new report of PGPR. In presence of selected PGPR strains, the changes in population densities of Acidobacteria were monitored in metagenomic DNA extracted from bulk and rhizospheric soils of tomato and black gram using real time qPCR. A gradual increase in equivalent cell numbers of Acidobacteria members was observed over time along with a simultaneous increase in plant growth promotion by test PGPR. We report characterization of three effective PGPR strains and their effects on indigenous, underexplored difficult-to-culture phylum-Acidobacteria. We suggest that putative interactions between these two bacterial groups thriving in rhizospheric soils could be beneficial for plant growth. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Effect of overwintering on the frequency of flies infected by the rhabdovirus sigma in experimental populations of Drosophila melanogaster.

    Science.gov (United States)

    Fleuriet, A

    1981-01-01

    Artificial overwintering, assuming that adulthood is the overwintering stage, has been performed on six experimental populations of Drosophila melanogaster. In five of them, the frequency of flies infected by the hereditary Rhabdovirus sigma is always in the first spring generation than it was in the last generation of the preceding fall. This result might indicate a higher sensitivity of infected flies to winter conditions, but other interpretations, connected with the genes for resistance to the virus might be considered. In one of the six populations, no effect was detected after any of the three successive winters. It appears therefore that the genetic background of the flies or/and of the propagated virus intervenes in the response to overwintering.

  17. Genetic consequences of the combined effect of ionizing radiation and copper vitriol on experimental Drosophila melanogaster populations

    International Nuclear Information System (INIS)

    Glushkova, I.V.; Anoshenko, I.P.; Malei, L.P.; Pechkovskaya, A.V.

    2004-01-01

    The paper studies the influence of the combined effect of gamma-irradiation (15 Gy/generation) and copper vitriol (1 mM concentration) on experimental Dr. melanogaster population with the help of the tests of morphogenetic variability and dominant lethal mutations (DLM). The frequency of morphogenetically changed phenotypes increased under the influence of mutagenic factors of diverse origin and their spectrum was practically unchanged. The DLM test has shown that irradiation and the combined effect of chemical and physical factors exerted a damaging effect, while Cu salt acted as sensitizer considerably intensifying radiation effect. (authors)

  18. 76 FR 35979 - Endangered and Threatened Wildlife and Plants; Establishment of a Nonessential Experimental...

    Science.gov (United States)

    2011-06-21

    ..., p. 13; Taylor et al. 1999, p. 1162). At a coarse scale, these assessments have identified the... Creek and Rush Creek populations that occur above Swift Dam. For the Deschutes River basin, it included...

  19. Full scale experimental study of a small natural draft dry cooling tower for concentrating solar thermal power plant

    International Nuclear Information System (INIS)

    Li, Xiaoxiao; Duniam, Sam; Gurgenci, Hal; Guan, Zhiqiang; Veeraragavan, Anand

    2017-01-01

    Highlights: • A 20 m high natural draft dry cooling tower is designed and tested. • The cooling tower model is refined and validated with the experimental data. • The performance of the cooling tower utilized in a CST power plant is investigated. • Ambient temperature effect on Rankine cycle and Brayton cycle is discussed. - Abstract: Concentrating solar thermal power system can provide low carbon, renewable energy resources in countries or regions with strong solar irradiation. For this kind of power plant which is likely to be located in the arid area, natural draft dry cooling tower is a promising choice. To develop the experimental studies on small cooling tower, a 20 m high natural draft dry cooling tower with fully instrumented measurement system was established by the Queensland Geothermal Energy Centre of Excellence. The performance of this cooling tower was measured with the constant heat input of 600 kW and 840 kW and with ambient temperature ranging from 20 °C to 32 °C. The cooling tower numerical model was refined and validated with the experimental data. The model of 1 MW concentrating solar thermal supercritical CO_2 power cycle was developed and integrated with the cooling tower model. The influences of changing ambient temperature and the performance of the cooling tower on efficiency of the power system were simulated. The differences of the mechanism of the ambient temperature effect on Rankine cycle and supercritical CO_2 Brayton cycle were analysed and discussed.

  20. Favorable results from the use of herbal and plant products in inflammatory bowel disease: evidence from experimental animal studies

    Science.gov (United States)

    Triantafillidis, John K.; Triantafyllidi, Aikaterini; Vagianos, Constantinos; Papalois, Apostolos

    2016-01-01

    The use of herbal therapy for inflammatory bowel disease is increasing worldwide. The aim of this study was to review the available literature on the efficacy of herbal therapy in experimental colitis. All relevant studies published in Medline and Embase up to June 2015 have been reviewed. The results of bowel histology and serum parameters have been recorded. A satisfactory number of published experimental studies, and a quite large one of both herbal and plant products tested in different studies have been reported. The results showed that in the majority of the studies, herbal therapy reduced the inflammatory activity of experimental colitis and diminished the levels of many inflammatory indices, including serum cytokines and indices of oxidative stress. The most promising plant and herbal products were tormentil extracts, wormwoodherb, Aloe vera, germinated barley foodstuff, curcumin, Boswellia serrata, Panax notoginseng, Ixeris dentata, green tea, Cordia dichotoma, Plantago lanceolata, Iridoidglycosides, and mastic gum. Herbal therapies exert their therapeutic benefit via various mechanisms, including immune regulation, anti-oxidant activity, inhibition of leukotriene B4 and nuclear factor-κB, and antiplatelet activity. Large, double-blind clinical studies assessing these natural substances should be urgently conducted. PMID:27366027

  1. Assessment of theoretical and experimental results in the calculation of atmospheric dilution factors in the Atucha I nuclear power plant

    International Nuclear Information System (INIS)

    Quintana, E.E.; Tossi, M.H.; Telleria, D.M.

    1990-01-01

    Collective doses produced during the normal working of the Atucha I Nuclear Power Plant are calculated using annual atmospheric factors. This work studies the behaviour of the dilution factors in different periods of the year in order to fit the calculated dose model applying factors from seasonal, monthly or weekly periods. The Radiation Protection Group of the C.N.E.A. have carried out continuous environmental monitoring in the surroundings of the Atucha I Nuclear Power Plant. These studies include the measurement of air tritium concentration, radionuclide that is found principally as tritiated water vapour. This isotope, normally released by the nuclear power plant was used as a tracer to assess the atmospheric dilution factors. Factors were calculated by two methods: an experimental one, based on environmental measurements of the tritium concentration in the surroundings of the nuclear power plant and another one by applying a theoretical model based on information from the micrometeorological tower located in the mentioned place. To carry out the environmental monitoring, four monitoring stations in the surroundings of the power plant were chosen. Three of them are approximately one kilometer from the plant and the fourth is 7.5 km away, near the city of Lima. To condense and collect the atmospheric water vapour, an overcooling system was used. The measurement was performed by liquid scintillation counting, previous alkaline electrolytical enrichment of the samples. The theoretical model uses hourly values of direction and wind intensity, as well as the atmospheric dispersive properties. Values obtained during the period 1976 to 1988 allowed, applying statistical tests, to validate the theoretical model and to observe seasonal variation of the dilution factors throughout the same year and between different years. Finally, results and graphics are presented showing that the behaviour of the dilution factors in different periods of the year. It is recommended to

  2. Effects of metal pollutants on magnetic and chemical properties of soils and plant biomass: experimental studies in Environmental Magnetism

    Science.gov (United States)

    Sapkota, Birendra

    Understanding the interactions and effects of biotic and abiotic factors on magnetic parameter measurements used to assess levels of pollutants requires experimental analysis of potential individual parameters. Using magnetic and chemical measurements, three separate experimental studies were conducted in order to evaluate the separate and combined effects of soil composition, atmospheric exposure, and contaminant levels on soil magnetic susceptibility (MS) measurements, plant growth and metal uptake by plants. Experiment 1 examined the effects of incorporating an artificial Fe-rich contaminant into a synthetic soil on surficial soil magnetic properties and plant growth inside a greenhouse. Periodic measurements of surficial soil MS showed significant decreases in MS values in the three treatments (two levels of Fe-contamination and controls), with the greatest reduction in soils with the most contamination, and the least in controls. Three potential causes were suggested: Fe uptake by plants, magnetic minerals transformation, and downward migration of Fe-particles. Some arguments for the first two causes were discussed; however, the third possibility was separately evaluated in the second and third experiments. In the follow-up study (Experiment 2) conducted to examine the effects of ambient atmospheric pollution on magnetic and chemical properties of soils and plant biomass, the overall surficial soil MS was found to be significantly higher in synthetic soils exposed to a natural atmosphere in comparison to controls placed in a greenhouse. Root biomass samples taken from the exposed soils had much higher trace/heavy metal concentrations. Such increases in soil MS and bioavailability of metals in the exposed soils indicate that atmospheric pollution affected the soil and plants grown in there. Microscopic observations of Fe-rich particles from the post-harvest exposed soil revealed morphologies similar to Fe-containing particulates from power plants and

  3. Experimental handling of sugar beets in the alcohol plant at Lipetsk. [USSR

    Energy Technology Data Exchange (ETDEWEB)

    Grachev, B K

    1958-01-01

    After introducing several technical improvements in the plant layout (flow scheme presented), especially in the cutting units which shred the beets, it is easily possible now by fermenting with strain XII or strain M to attain production with an EtOH of 87.2% by volume, which contains 0.05% andehydes, 254 mg/1 ester, and 21 mg/1 acid.

  4. Internal transport of alien and native plants by geese and ducks: an experimental study

    NARCIS (Netherlands)

    Garcia-Alvarez, Alberto; van Leeuwen, Casper H. A.; Luque, Carlos J.; Hussner, Andreas; Velez-Martin, Alberto; Perez-Vazquez, Andres; Green, Andy J.; Castellanos, Eloy M.

    2015-01-01

    Alien plant species are rapidly spreading in aquatic ecosystems around the world, causing major ecological effects. They are typically introduced by humans, after which natural vectors facilitate their further spread. Migratory waterbirds have long been recognised as important dispersal vectors for

  5. An experimental assessment of the upper elevational limit of flowering plants in the western Himalaya

    Czech Academy of Sciences Publication Activity Database

    Klimeš, Leoš; Doležal, Jiří

    2010-01-01

    Roč. 33, č. 3 (2010), s. 590-596 ISSN 0906-7590 R&D Projects: GA AV ČR IAA600050802; GA ČR GA206/03/1219 Institutional research plan: CEZ:AV0Z60050516 Keywords : species richness * vascular plants * species limits Subject RIV: EF - Botanics Impact factor: 4.417, year: 2010

  6. Dispersion of traffic exhausts in urban street canyons with tree plantings : experimental and numerical investigations

    NARCIS (Netherlands)

    Gromke, C.B.; Denev, J.; Ruck, B.

    2007-01-01

    Wind tunnel experiments and numerical computations have been performed in order to investigate the influence of avenuelike tree plantings on the dispersion of traffic exhaust in an urban street canyon. Reduced natural ventilation and enhanced pollutant concentrations have been found in the presence

  7. Theoretical and experimental investigations of thermal conditions of household biogas plant

    Directory of Open Access Journals (Sweden)

    Zhelykh Vasil

    2016-06-01

    Full Text Available The construction of domestic continuous bioreactor is proposed. The modeling of thermal modes of household biogas plant using graph theory was done. The correction factor taking into account with the influence of variables on its value was determined. The system of balance equations for the desired thermal conditions in the bioreactor was presented.

  8. Responses of predatory invertebrates to seeding density and plant species richness in experimental tallgrass prairie restorations

    Science.gov (United States)

    Nemec, Kristine T.; Allen, Craig R.; Danielson, Stephen D.; Helzer, Christopher J.

    2014-01-01

    In recent decades, agricultural producers and non-governmental organizations have restored thousands of hectares of former cropland in the central United States with native grasses and forbs. However, the ability of these grassland restorations to attract predatory invertebrates has not been well documented, even though predators provide an important ecosystem service to agricultural producers by naturally regulating herbivores. This study assessed the effects of plant richness and seeding density on the richness and abundance of surface-dwelling (ants, ground beetles, and spiders) and aboveground (ladybird beetles) predatory invertebrates. In the spring of 2006, twenty-four 55 m × 55 m-plots were planted to six replicates in each of four treatments: high richness (97 species typically planted by The Nature Conservancy), at low and high seeding densities, and low richness (15 species representing a typical Natural Resources Conservation Service Conservation Reserve Program mix, CP25), at low and high seeding densities. Ants, ground beetles, and spiders were sampled using pitfall traps and ladybird beetles were sampled using sweep netting in 2007–2009. The abundance of ants, ground beetles, and spiders showed no response to seed mix richness or seeding density but there was a significant positive effect of richness on ladybird beetle abundance. Seeding density had a significant positive effect on ground beetle and spider species richness and Shannon–Weaver diversity. These results may be related to differences in the plant species composition and relative amount of grass basal cover among the treatments rather than richness.

  9. Effects of experimental snowmelt and rain on dispersal of six plant species

    NARCIS (Netherlands)

    Sarneel, J. M.

    2016-01-01

    Water flows affect dispersal of propagules of many plant species, and rivers and streams are therefore very important dispersal vectors. However, small water flows such as trough rain and snowmelt are much more common, but their effects on dispersal are barely studied. The importance of this form of

  10. Yield and quality of sweet corn at different plant populationsProdutividade e qualidade do milho doce em diferentes populações de plantas

    Directory of Open Access Journals (Sweden)

    Renan Soares de Souza

    2013-06-01

    Full Text Available The objective of this study was to evaluate the plant population density effect upon yield components and the chemical composition of grains in two sweet corn hybrids in “Winter-Spring” cultivation. The experimental design used was the complete randomized blocks with four replications. The treatments were based on the combination between two sweet corn hybrids (Tropical Plus e RB-6324 and five plant populations (40,000, 55.000, 70,000, 85,000 and 100,000 plants ha-1, in a factorial scheme 2 x 5, evaluated in two “winter-spring” growing seasons (2009 and 2010. The increment in the population of 40,000 to 100,000 plants ha-1 resulted in higher husked commercial corn ear productivity in both hybrids, Tropical Plus and RB-6324. The increase of plant population reduced the length and diameter of corn ears in Tropical Plus and RB-6324. The mass of the corn ears from Tropical Plus also reduced; however, it did not affect the commercial standard and industrial use. In larger plant populations the hybrid RB-6324 produced corn ears with grains that were sweeter and with lower starch content. The hybrid Tropical Plus presented higher mass, length, productivity, sugar content and lower diameter of corn ears when compared to RB-6324.O objetivo do presente estudo foi avaliar o efeito da população de plantas sobre os componentes de produção e a composição química de grãos de dois híbridos de milho doce no cultivo de “Inverno – Primavera”. O delineamento experimental utilizado foi o de blocos completos casualizados com quatro repetições. Os tratamentos constituíram-se da combinação entre híbridos de milho doce (Tropical Plus e RB-6324 e populações de plantas (40.000, 55.000, 70.000, 85.000 e 100.000 plantas ha-1, no esquema fatorial 2 x 5, avaliados em dois anos agrícolas (2009 e 2010, em cultivo de Inverno-Primavera. O incremento na população de plantas de 40.000 até 100.000 plantas ha-1 resultou em maiores produtividades de

  11. An experimental set-up to study carbon, water, and nitrate uptake rates by hydroponically grown plants.

    Science.gov (United States)

    Andriolo, J L; Le Bot, J; Gary, C; Sappe, G; Orlando, P; Brunel, B; Sarrouy, C

    1996-01-01

    The experimental system described allows concomitant hourly measurements of CO2, H2O, and NO3 uptake rates by plants grown hydroponically in a greenhouse. Plants are enclosed in an airtight chamber through which air flows at a controlled speed. Carbon dioxide exchange and transpiration rates are determined from respective differences of concentrations of CO2 and water vapor of the air at the system inlet and outlet. This set-up is based on the "open-system" principle with improvements made on existing systems. For instance, propeller anemometers are used to monitor air flow rates in the chamber. From their signal it is possible to continuously adjust air speed to changing environmental conditions and plant activity. The air temperature inside the system therefore never rises above that outside. Water and NO3 uptake rates are calculated at time intervals from changes in the volume and the NO3 concentration of the nutrient solution in contact with the roots. The precise measurement of the volume of solution is achieved using a balance which has a higher precision than any liquid level sensors. Nitrate concentration is determined in the laboratory from aliquots of solution sampled at time intervals. A number of test runs are reported which validate the measurements and confirm undisturbed conditions within the system. Results of typical diurnal changes in CO2, H2O, and NO3 uptake rates by fruiting tomato plants are also presented.

  12. Oral delivery of ACE2/Ang-(1-7) bioencapsulated in plant cells protects against experimental uveitis and autoimmune uveoretinitis.

    Science.gov (United States)

    Shil, Pollob K; Kwon, Kwang-Chul; Zhu, Ping; Verma, Amrisha; Daniell, Henry; Li, Qiuhong

    2014-12-01

    Hyperactivity of the renin-angiotensin system (RAS) resulting in elevated Angiotensin II (Ang II) contributes to all stages of inflammatory responses including ocular inflammation. The discovery of angiotensin-converting enzyme 2 (ACE2) has established a protective axis of RAS involving ACE2/Ang-(1-7)/Mas that counteracts the proinflammatory and hypertrophic effects of the deleterious ACE/AngII/AT1R axis. Here we investigated the hypothesis that enhancing the systemic and local activity of the protective axis of the RAS by oral delivery of ACE2 and Ang-(1-7) bioencapsulated in plant cells would confer protection against ocular inflammation. Both ACE2 and Ang-(1-7), fused with the non-toxic cholera toxin subunit B (CTB) were expressed in plant chloroplasts. Increased levels of ACE2 and Ang-(1-7) were observed in circulation and retina after oral administration of CTB-ACE2 and Ang-(1-7) expressing plant cells. Oral feeding of mice with bioencapsulated ACE2/Ang-(1-7) significantly reduced endotoxin-induced uveitis (EIU) in mice. Treatment with bioencapsulated ACE2/Ang-(1-7) also dramatically decreased cellular infiltration, retinal vasculitis, damage and folding in experimental autoimmune uveoretinitis (EAU). Thus, enhancing the protective axis of RAS by oral delivery of ACE2/Ang-(1-7) bioencapsulated in plant cells provide an innovative, highly efficient and cost-effective therapeutic strategy for ocular inflammatory diseases.

  13. Population morbidity in the Zaporizhzhia Nuclear Power Plant observation zone as an integral part of public health.

    Science.gov (United States)

    Khomenko, I M; Zakladna, N V; Orlova, N M

    2017-12-01

    To evaluate the health status of adult population living in the Ukrainian nuclear power industry obser vation zone on the example of Zaporizhzhia Nuclear Power Plant. System review, analytic, sociological survey and statistical methods. There was established an increase in the incidence of digestive diseases among adult population in Nikopol of Dnipropetrovsk region, which is included in the Zaporizhzhia NPP observation zone. The highest increase was observed in the incidence of peptic ulcer, gastritis and duodenitis, cholecystitis and cholangitis by 340 %, 305 % and 83 %, respectively. In connection with the residence in industrially developed region and NPP life extension in Ukraine, the possible influence of harmful factors on health status of the population of observation zones, an increase in the incidence of digestive diseases among adult population, there is required continuous monitoring and detailed study of public health. I. M. Khomenko, N. V. Zakladna, N. M. Orlova.

  14. Experimental investigations of overvoltages in 6kV station service cable networks of thermal power plants

    Energy Technology Data Exchange (ETDEWEB)

    Vukelja, P.I.; Naumov, R.M.; Drobnjak, G.V.; Mrvic, J.D. [Nikola Tesla Inst., Belgrade (Yugoslavia)

    1996-12-31

    The paper presents the results of experimental investigations of overvoltages on 6kV isolated neutral station service cable networks of thermal power plants. The overvoltages were recorded with capacitive voltage measurement systems made at the Nikola Tesla Institute. Wideband capacitive voltage measurement systems recorded a flat response from below power frequencies to 10MHz. Investigations of overvoltages were performed for appearance and interruption of metal earth faults, intermittent earth faults, switching operation of HV motors switchgear, switching operation of transformers switchgear, and transfer of the network supply from one transformer to another. On the basis of these investigations, certain measures are proposed for limiting overvoltages and for the reliability of station service of thermal power plants.

  15. Varying Herbivore Population Structure Correlates with Lack of Local Adaptation in a Geographic Variable Plant-Herbivore Interaction

    Science.gov (United States)

    Cogni, Rodrigo; Trigo, José R.; Futuyma, Douglas J.

    2011-01-01

    Local adaptation of parasites to their hosts due to coevolution is a central prediction of many theories in evolutionary biology. However, empirical studies looking for parasite local adaptation show great variation in outcomes, and the reasons for such variation are largely unknown. In a previous study, we showed adaptive differentiation in the arctiid moth Utetheisa ornatrix to its host plant, the pyrrolizidine alkaloid-bearing legume Crotalaria pallida, at the continental scale, but found no differentiation at the regional scale. In the present study, we sampled the same sites to investigate factors that may contribute to the lack of differentiation at the regional scale. We performed field observations that show that specialist and non-specialist polyphagous herbivore incidence varies among populations at both scales. With a series of common-garden experiments we show that some plant traits that may affect herbivory (pyrrolizidine alkaloids and extrafloral nectaries) vary at the regional scale, while other traits (trichomes and nitrogen content) just vary at the continental scale. These results, combined with our previous evidence for plant population differentiation based on larval performance on fresh fruits, suggest that U. ornatrix is subjected to divergent selection even at the regional scale. Finally, with a microsatellite study we investigated population structure of U. ornatrix. We found that population structure is not stable over time: we found population differentiation at the regional scale in the first year of sampling, but not in the second year. Unstable population structure of the herbivore is the most likely cause of the lack of regional adaptation. PMID:22220208

  16. Varying herbivore population structure correlates with lack of local adaptation in a geographic variable plant-herbivore interaction.

    Directory of Open Access Journals (Sweden)

    Rodrigo Cogni

    Full Text Available Local adaptation of parasites to their hosts due to coevolution is a central prediction of many theories in evolutionary biology. However, empirical studies looking for parasite local adaptation show great variation in outcomes, and the reasons for such variation are largely unknown. In a previous study, we showed adaptive differentiation in the arctiid moth Utetheisa ornatrix to its host plant, the pyrrolizidine alkaloid-bearing legume Crotalaria pallida, at the continental scale, but found no differentiation at the regional scale. In the present study, we sampled the same sites to investigate factors that may contribute to the lack of differentiation at the regional scale. We performed field observations that show that specialist and non-specialist polyphagous herbivore incidence varies among populations at both scales. With a series of common-garden experiments we show that some plant traits that may affect herbivory (pyrrolizidine alkaloids and extrafloral nectaries vary at the regional scale, while other traits (trichomes and nitrogen content just vary at the continental scale. These results, combined with our previous evidence for plant population differentiation based on larval performance on fresh fruits, suggest that U. ornatrix is subjected to divergent selection even at the regional scale. Finally, with a microsatellite study we investigated population structure of U. ornatrix. We found that population structure is not stable over time: we found population differentiation at the regional scale in the first year of sampling, but not in the second year. Unstable population structure of the herbivore is the most likely cause of the lack of regional adaptation.

  17. State of the art of computer codes and experimental investigations on safety of nuclear power plants with reactors of WWER type

    International Nuclear Information System (INIS)

    Asmolov, V.G.; Volkov, G.A.; Elikin, I.V.; Mysenkov, A.I.

    1987-01-01

    As is well-known investigations on mathematical models of accidental situations from the point of view of nuclear safety as well as their experimental investigation are of great importance in the design of reactor units for nuclear power plants. This paper gives a review of the state of the art of thermodynamic models and computer codes used for safety analysis of WWER reactors in the USSR, the experimental basis and experimental investigations of the appropriate thermal processes. The actual and future trends of theoretical and experimental investigation on safety problems of WWER type nuclear power plants are briefly described. (author)

  18. Siting of Nuclear Power Plants in Metropolitan Areas. Estimation of Population Doses due to Accidental Release of Fission Products

    Energy Technology Data Exchange (ETDEWEB)

    Bresser, H. [Technischer Ueberwachungs-Verein Rheinland E.V., Cologne (Germany); Schwarzer, W. [Institut fuer Reaktorsicherheit der Technischen Ueberwachungs-Vereine E.V., Cologne (Germany)

    1967-09-15

    The safety of large nuclear power plants in heavily populated areas depends entirely on engineered safeguards. An assessment of their reliability and effectiveness will have to play a major role in any safety analysis of such a plant, and this assessment will have to be made on the basis of the radiological burden to the environment - in terms of individual dose and a population dose - which can be accepted as tolerable in case of a severe accident. The calculation of the dispersion of fission products in the atmosphere, which links the radiological burden to the release of radioactivity, should be modified. The fact that distance factors, aside from a comparably small exclusion area, can no longer be taken into account suggests the introduction of the parameter ''population density'' and an extensive use of the man-rem concept. In this connection the time history of the release and the influence of variations of wind directions lose their importance. The authors have carried out calculations of the population dose, which could be received in a metropolitan area as a consequence of a severe reactor accident, using population densities, height of release above ground and generalized meteorological data as the main parameters. The results of these calculations are used as a basis for an assessment of the performance requirements of the engineered safeguards system, and the relative importance of different components of this system is discussed. (author)

  19. Application of Modern Experimental Technique to Solve Morphological Complexity in Plants Taxonomy

    Directory of Open Access Journals (Sweden)

    SURANTO

    2000-07-01

    Full Text Available Modern taxonomy has two approaches, i.e. classical and experimental taxonomy. Classical taxonomy uses morphological characters, while experimental taxonomy uses broader methods including chemistry, physics and mathematics, in the form of laboratory data that are revealed together with the progress of optical technique (microscope, chemistry methods (chromatography, electrophoresis, etc. Modern taxonomy tends to use series of interrelated data. More data used would result in more validity and give better clarification of taxonomic status. A lot of modern taxonomic data such as palynology, cytotaxonomy (cytology, chemical constituent (chemotaxonomy, isozyme and DNA sequencing were used recently.

  20. Whole-Genome Resequencing of Experimental Populations Reveals Polygenic Basis of Egg-Size Variation in Drosophila melanogaster.

    Science.gov (United States)

    Jha, Aashish R; Miles, Cecelia M; Lippert, Nodia R; Brown, Christopher D; White, Kevin P; Kreitman, Martin

    2015-10-01

    Complete genome resequencing of populations holds great promise in deconstructing complex polygenic traits to elucidate molecular and developmental mechanisms of adaptation. Egg size is a classic adaptive trait in insects, birds, and other taxa, but its highly polygenic architecture has prevented high-resolution genetic analysis. We used replicated experimental evolution in Drosophila melanogaster and whole-genome sequencing to identify consistent signatures of polygenic egg-size adaptation. A generalized linear-mixed model revealed reproducible allele frequency differences between replicated experimental populations selected for large and small egg volumes at approximately 4,000 single nucleotide polymorphisms (SNPs). Several hundred distinct genomic regions contain clusters of these SNPs and have lower heterozygosity than the genomic background, consistent with selection acting on polymorphisms in these regions. These SNPs are also enriched among genes expressed in Drosophila ovaries and many of these genes have well-defined functions in Drosophila oogenesis. Additional genes regulating egg development, growth, and cell size show evidence of directional selection as genes regulating these biological processes are enriched for highly differentiated SNPs. Genetic crosses performed with a subset of candidate genes demonstrated that these genes influence egg size, at least in the large genetic background. These findings confirm the highly polygenic architecture of this adaptive trait, and suggest the involvement of many novel candidate genes in regulating egg size. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  1. Application of the failure modes and effects analysis technique to the emergency cooling system of an experimental nuclear power plant

    International Nuclear Information System (INIS)

    Conceicao Junior, Osmar; Silva, Antonio Teixeira e

    2009-01-01

    This study consists on the application of the failure modes and effects analysis (FMEA), a hazard identification and a risk assessment technique, to the emergency cooling system (ECS), of an experimental nuclear power plant. The choice of this technique was due to its detailed analysis of each component of the system, enabling the identification of all possible ways of failure and its related consequences (in order of importance), allowing the designer to improve the system, maximizing its security and reliability. Through the application of this methodology, it could be observed that the ECS is an intrinsically safe system, in spite of the modifications proposed. (author)

  2. Application of the failure modes and effects analysis technique to theemergency cooling system of an experimental nuclear power plant

    International Nuclear Information System (INIS)

    Conceicao Junior, Osmar

    2009-01-01

    This study consists on the application of the Failure Modes and EffectsAnalysis (FMEA), a hazard identification and a risk assessment technique, tothe Emergency Cooling System (ECS) of an experimental nuclear power plant,which is responsible for mitigating the consequences of an eventual loss ofcoolant accident on the Pressurized Water Reactor (PWR). Such analysisintends to identify possible weaknesses on the design of the system andpropose some improvements in order to maximize its reliability. To achievethis goal a detailed study of the system was carried on (through itstechnical documentation), the correspondent reliability block diagram wasobtained, the FMEA analysis was executed and, finally, some suggestions werepresented. (author)

  3. Statistical investigations of the failure behaviour of components in the AVR-experimental nuclear power plant. Vol. 1

    International Nuclear Information System (INIS)

    Hennings, W.

    1989-08-01

    From operational reports of the years 1970 to 1984, failure rates of valves in gas circuits of the AVR experimental power plant were determined. Also, potential influences of environmental and operational conditions were investigated. The resulting failure rates are for manual valves app. 0,1.10 -6 /h, for pneumatic valves between 3 and 9.10 -6 /h, for solenoid valves between 1,5 and 4.10 -6 /h and for control valves between 12 and 41.10 -6 /h. (orig.) [de

  4. Medicinal plants of Papua New Guinea's Miu speaking population and a focus on their use of plant-slaked lime mixtures.

    Science.gov (United States)

    Prescott, Thomas A K; Briggs, Marie; Kiapranis, Robert; Simmonds, Monique S J

    2015-11-04

    Here we present the results of an ethnobotanical survey of the medicinal plants used by the Miu, a virtually unresearched ethnolinguistic group who live in the mountainous interior of Papua New Guinea's West New Britain Province. We compare the findings for those previously reported for the neighbouring inland Kaulong speaking population. Three species, Trema orientalis, Spondias dulcis and Ficus botryocarpa are used in combination with locally prepared slaked lime to produce intensely coloured mixtures which are applied to dermatological infections. Their effects on dermal fibroblast viability with and without slaked lime are examined. The sap of F. botryocarpa which is used to treat tropical ulcers was examined further with assays relevant to wound healing. Focus groups and semi-structured interviews were used to acquire information on the uses of plants, vouchers of which were collected and identified by comparison with authentic herbarium specimens. LC-MS and NMR were used to identify chemical components. Cell viability assays were used to examine the effects of added slaked lime on dermal fibroblasts. For the sap of F. botryocarpa, fibroblast stimulation assays and antibacterial growth inhibition with Bacillus subtilis were carried out. The survey identified 33 plants and one fungal species, and clear differences with the inland Kaulong group despite their close proximity. Added slaked lime does not greatly increase the cytotoxicity of plant material towards dermal fibroblasts. The sap of F. botryocarpa contains the alkaloid ficuseptine as a single major component and displays antibacterial activity. The results demonstrate the potential for variation in medicinal plant use amongst Papua New Guinea's numerous language groups. The addition of slaked lime to plant material does not appear to present a concern for wound healing in the amounts used. The sap of F. botryocarpa displays antibacterial activity at concentrations that would occur at the wound surface

  5. Effects of plant density on forage production in five populations of ...

    African Journals Online (AJOL)

    Kleingrass (Panicum coloratum L.) forage yield evaluation plots are often established at a density of 6.0 plants m-2 to accommodate mechanical transplanting and harvesting equipment. However, forage crops are usually established from seed at higher plant densities. Experiments were conducted to determine if ...

  6. Are population differences in plant quality reflected in the preference and performance of two endoparasitoid wasps?

    NARCIS (Netherlands)

    Gols, R.; Dam, van N.M.; Raaijmakers, C.E.; Dicke, M.; Harvey, J.A.

    2009-01-01

    In recent years, increasing attention has been paid in exploring the role of direct plant defence, through the production of allelochemicals, on the performance of parasitoid wasps and their hosts. However, few studies have determined if parasitoids can detect differences in plant quality and thus

  7. Cancer incidence in the vicinity of nuclear power plants in Taiwan: a population-based study.

    Science.gov (United States)

    Wang, Shiow-Ing; Yaung, Chih-Liang; Lee, Long-Teng; Chiou, Shang-Jyh

    2016-01-01

    Numerous antinuclear demonstrations reveal that the public is anxious about the potential health effects caused by nuclear power plants. The purpose of this study is to address the question "Is there a higher cancer incidence rate in the vicinity of nuclear power plants in Taiwan?" The Taiwan Cancer Registry database from 1979 to 2003 was used to compare the standardized incidence rate of the top four cancers with strong evidence for radiation risks between the "plant-vicinity" with those "non-plant-vicinity" groups. All cancer sites, five-leading cancers in Taiwan, and gender-specific cancers were also studied. We also adopted different observation time to compare the incidence rate of cancers between two groups to explore the impact of the observation period. The incidences of leukemia, thyroid, lung, and breast cancer were not significantly different between two groups, but cervix uteri cancer showed higher incidence rates in the plant-vicinity group. The incidence of cervical cancer was not consistently associated with the duration of plant operation, according to a multiyear period comparison. Although there was higher incidence in cervix cancer in the plant-vicinity group, our findings did not provide the crucial evidence that nuclear power plants were the causal factor for some cancers with strong evidence for radiation risks.

  8. Microvessel organization and structure in experimental brain tumors: microvessel populations with distinctive structural and functional properties.

    Science.gov (United States)

    Schlageter, K E; Molnar, P; Lapin, G D; Groothuis, D R

    1999-11-01

    We studied microvessel organization in five brain tumor models (ENU, MSV, RG-2, S635cl15, and D-54MG) and normal brain, including microvessel diameter (LMVD), intermicrovessel distance (IMVD), microvessel density (MVD), surface area (S(v)), and orientation. LMVD and IMVD were larger and MVD was lower in tumors than normal brain. S(v) in tumors overlapped normal brain values and orientation was random in both tumors and brain. ENU and RG-2 tumors and brain were studied by electron microscopy. Tumor microvessel wall was thicker than that of brain. ENU and normal brain microvessels were continuous and nonfenestrated. RG-2 microvessels contained fenestrations and endothelial gaps; the latter had a maximum major axis of 3.0 microm. Based on anatomic measurements, the pore area of RG-2 tumors was estimated at 7.4 x 10(-6) cm(2) g(-1) from fenestrations and 3.5 x 10(-5) cm(2) g(-1) from endothelial gaps. Increased permeability of RG-2 microvessels to macromolecules is most likely attributable to endothelial gaps. Three microvessel populations may occur in brain tumors: (1) continuous nonfenestrated, (2) continuous fenestrated, and (3) discontinuous (with or without fenestrations). The first group may be unique to brain tumors; the latter two are similar to microvessels found in systemic tumors. Since structure-function properties of brain tumor microvessels will affect drug delivery, studies of microvessel function should be incorporated into clinical trials of brain tumor therapy, especially those using macromolecules. Copyright 1999 Academic Press.

  9. Rates of change in climatic niches in plant and animal populations are much slower than projected climate change

    Science.gov (United States)

    Jezkova, Tereza

    2016-01-01

    Climate change may soon threaten much of global biodiversity. A critical question is: can species undergo niche shifts of sufficient speed and magnitude to persist within their current geographic ranges? Here, we analyse niche shifts among populations within 56 plant and animal species using time-calibrated trees from phylogeographic studies. Across 266 phylogeographic groups analysed, rates of niche change were much slower than rates of projected climate change (mean difference > 200 000-fold for temperature variables). Furthermore, the absolute niche divergence among populations was typically lower than the magnitude of projected climate change over the next approximately 55 years for relevant variables, suggesting the amount of change needed to persist may often be too great, even if these niche shifts were instantaneous. Rates were broadly similar between plants and animals, but especially rapid in some arthropods, birds and mammals. Rates for temperature variables were lower at lower latitudes, further suggesting that tropical species may be especially vulnerable to climate change. PMID:27881748

  10. Accumulation of americium-241 in the biomass of aquatic plants of the Yenisei river: experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Zotina, T.A.; Bolsunovsky, A.Y.A.; Bondareva, L.G. [Institute of Biophysics SB RAS, Akademgorodok, Krasnoyarsk (Russian Federation)

    2004-07-01

    Due to the operation of the Mining-and-Chemical Combine (Krasnoyarsk-26), which has been manufacturing weapons-grade plutonium for several decades, the Yenisei River is contaminated with transuranic elements (including {sup 241}Am). {sup 241}Am was found in the riverside soil, sediment and in the biomass of aquatic plants (Bolsunovsky et al., 1999, 2002). Aquatic plants are an important link in the migration of radionuclides in an aquatic ecosystem. In laboratory experiments, we investigated accumulation of {sup 241}Am by the submerged macrophyte from the Yenisei River: the pond weed (Elodea canadensis) and the aquatic moss (Fontinalis antipyretica), and release of {sup 241}Am from the biomass. The content of {sup 241}Am was measured on a Canberra (USA) gamma-spectrometer. The experiments showed that specific accumulation and concentration factors of {sup 241}Am in the plants were in inverse proportion to their biomass. We obtained new data on release of {sup 241}Am from the biomass of macrophyte. Americium-241 was more firmly fixed in the biomass of the aquatic moss. In 12 months, the biomass of the aquatic moss released about 30% of the initial americium activity into the water. To compare, the biomass of the pond weed released into the water medium up to 64% of the initial {sup 241}Am activity in 1.5 4 months. The release rate was dependent on the decomposition rate of the plant biomass. The experiments showed that submerged macrophyte of the Yenisei River can accumulate considerable activities of {sup 241}Am and retain americium for long periods of time in biomass. (author)

  11. Accumulation of americium-241 in the biomass of aquatic plants of the Yenisei river: experimental study

    International Nuclear Information System (INIS)

    Zotina, T.A.; Bolsunovsky, A.Y.A.; Bondareva, L.G.

    2004-01-01

    Due to the operation of the Mining-and-Chemical Combine (Krasnoyarsk-26), which has been manufacturing weapons-grade plutonium for several decades, the Yenisei River is contaminated with transuranic elements (including 241 Am). 241 Am was found in the riverside soil, sediment and in the biomass of aquatic plants (Bolsunovsky et al., 1999, 2002). Aquatic plants are an important link in the migration of radionuclides in an aquatic ecosystem. In laboratory experiments, we investigated accumulation of 241 Am by the submerged macrophyte from the Yenisei River: the pond weed (Elodea canadensis) and the aquatic moss (Fontinalis antipyretica), and release of 241 Am from the biomass. The content of 241 Am was measured on a Canberra (USA) gamma-spectrometer. The experiments showed that specific accumulation and concentration factors of 241 Am in the plants were in inverse proportion to their biomass. We obtained new data on release of 241 Am from the biomass of macrophyte. Americium-241 was more firmly fixed in the biomass of the aquatic moss. In 12 months, the biomass of the aquatic moss released about 30% of the initial americium activity into the water. To compare, the biomass of the pond weed released into the water medium up to 64% of the initial 241 Am activity in 1.5 4 months. The release rate was dependent on the decomposition rate of the plant biomass. The experiments showed that submerged macrophyte of the Yenisei River can accumulate considerable activities of 241 Am and retain americium for long periods of time in biomass. (author)

  12. Experimental studies on SO/sub 2/ injuries in higher plants. Part 4

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, H; Takanashi, T; Yatazawa, M

    1970-01-01

    The effect of sulfur dioxide on aminoacid metabolism was examined. Wheat seedlings one month old (20 cm) were exposed to 0.5 ppm SO/sub 2/ at 22/sup 0/C, and 40% humidity for four days, only during the day. A Beckman 1200 aminoacid analyzer revealed only slight effects, but it was conjectured that the plant had some separate amino acid in its body prior to the test, and that the effect of SO/sub 2/ was relatively low. A similar wheat seedling was placed in a closed glass container and was exposed to 300 ppm carbon dioxide (14) and 100 ppm SO/sub 2/ for 30 min under 4000 lux. The first paper chromatography of 80% ethanol solubles from the leaves revealed that Ala. value had increased but sir. had decreased in half. The second paper chromatography revealed that in both test and control plants, four kinds of material in amino acid had taken in C(14), and two of the four were Ser. Ala. The total C(14) taken in by the test material under SO/sub 2/ exposure showed a noted decrease. The experiment proved that exposure of a plant to a high concentration of SO/sub 2/ produced hydroxysulfonate in metabolism and impaired its glycol acid function.

  13. Experimental investigation of the chemical looping method on a 1 MW pilot plant

    International Nuclear Information System (INIS)

    Orth, Matthias

    2014-01-01

    Attempting to counteract the consequences of climate change, leading industrial nations have agreed on reducing their CO 2 emissions significantly. To reach these reduction goals, it is essential to reduce the CO 2 emissions in the field of energy conversion. This PHD thesis covers the field of chemical looping combustion, a technology that uses fossil fuels for energy conversion with inherent capture of CO 2 . Since the research regarding chemical looping had so far focused mainly on lab scale or small scale experiments, a 1 MW pilot plant has been erected at Technische Universitaet Darmstadt in order to investigate the process in a semi-industrial scale and to check the process efficiency with commercially usable equipment. This pilot consists of two interconnected fluidized bed reactors and has an overall height of more than 11 m. In this thesis, some experiments with ilmenite - used as the oxygen carrier - are explained. Furthermore, the design, erection and commissioning of the pilot plant are presented as well as the results of the first test campaigns. The evaluation of the latter proves that the process can be handled in the design configuration and that CO 2 can be safely captured in a pilot plant of this scale.

  14. Evaluation of anti-inflammatory activity of some Libyan medicinal plants in experimental animals

    Directory of Open Access Journals (Sweden)

    Nahar Lutfun

    2012-01-01

    Full Text Available Ballota pseudodictamnus (L. Benth. (Lamiaceae, Salvia fruticosa Mill. (Lamiaceae and Thapsia garganica L. (Apiaceae are three well-known medicinal plants from the Libyan flora, which have long been used for the treatment of inflammations. The aim of the present study was to investigate, for the first time, the anti-inflammatory property of the methanol (MeOH extracts of the aerial parts of these plants. Shade-dried and ground aerial parts of B. pseudodictamnus, S. fruticosa and T. garganica were Soxhlet-extracted with MeOH. The extracts were concentrated by evaporation under reduced pressure at 40°C. The anti-inflammatory activity of the extracts was evaluated using the carrageenan-induced mice paw edema model. The administration of the extracts at a dose of 500 mg/kg body weight produced statistically significant inhibition (p < 0.05 of edema within 3 h of carrageenan administration. The results demonstrated significant anti-inflammatory properties of the test extracts. Among the extracts, the S. fruticosa extract exhibited the most significant inhibition of inflammation after 3 h (62.1%. Thus, S. fruticosa could be a potential source for the discovery and development of newer anti-inflammatory ‘leads’ for drug development. The anti-inflammatory activity of B. pseudodictamnus and S. fruticosa could be assumed to be related to high levels of phenolic compounds, e.g., flavonoids, present in these plants.

  15. Plant recolonization in the Himalaya from the southeastern Qinghai-Tibetan Plateau: Geographical isolation contributed to high population differentiation.

    Science.gov (United States)

    Cun, Yu-Zhi; Wang, Xiao-Quan

    2010-09-01

    The Himalaya-Hengduan Mountains region (HHM) in the southern and southeastern Qinghai-Tibetan Plateau (QTP) is considered an important reservoir and a differentiation center for temperate and alpine plants in the Cenozoic. To reveal how plants responded to the Quaternary climatic oscillations in the QTP, the phylogeographical histories of a few subalpine and alpine plants have been investigated, but nearly all studies used only uniparentally inherited cytoplasmic DNA markers, and only a couple of them included sampling from the Himalaya. In this study, range-wide genetic variation of the Himalayan hemlock (Tsuga dumosa), an important forest species in the HHM, was surveyed using DNA markers from three genomes. All markers revealed genetic depauperation in the Himalaya and richness in the Hengduan Mountains populations. Surprisingly, population differentiation of this wind-pollinated conifer is very high in all three genomes, with few common and many private nuclear gene alleles. These results, together with fossil evidence, clearly indicate that T. dumosa recolonized the Himalaya from the Hengduan Mountains before the Last Glacial Maximum (LGM), accompanied with strong founder effects, and the influence of the earlier glaciations on demographic histories of the QTP plants could be much stronger than that of the LGM. The strong population differentiation in T. dumosa could be attributed to restricted gene flow caused by the complicated topography in the HHM that formed during the uplift of the QTP, and thus sheds lights on the importance of geographical isolation in the development of high plant species diversity in this biodiversity hotspot. Copyright 2010 Elsevier Inc. All rights reserved.

  16. Population survey of phytoseiid mites and spider mites on peach leaves and wild plants in Japanese peach orchard.

    Science.gov (United States)

    Wari, David; Yamashita, Jun; Kataoka, Yoko; Kohara, Yoko; Hinomoto, Norihide; Kishimoto, Hidenari; Toyoshima, Shingo; Sonoda, Shoji

    2014-07-01

    A population survey of phytoseiid mites and spider mites was conducted on peach leaves and wild plants in Japanese peach orchards having different pesticide practices. The phytoseiid mite species composition on peach leaves and wild plants, as estimated using quantitative sequencing, changed during the survey period. Moreover, it varied among study sites. The phytoseiid mite species compositions were similar between peach leaves and some wild plants, such as Veronica persica, Paederia foetida, Persicaria longiseta, and Oxalis corniculata with larger quantities of phytoseiid mites, especially after mid-summer. A PCR-based method to detect the ribosomal ITS sequences of Tetranychus kanzawai and Panonychus mori from phytoseiid mites was developed. Results showed that Euseius sojaensis (specialized pollen feeder/generalist predator) uses both spider mites as prey in the field.

  17. Tree harvest in an experimental sand ecosystem: plant effects on nutrient dynamics and solute generation.

    Science.gov (United States)

    C. K. Keller; R. O' Brien; J. R. Havig; J. L. Smith; B. T. Bormann; D. Wang

    2006-01-01

    The hydrochemical signatures of forested ecosystems are known to be determined by a time-variant combination of physical-hydrologic, geochemical, and biologic processes. We studied subsurface potassium (K), calcium (Ca), and nitrate (NO3) in an experimental red-pine mesocosm to determine how trees affect the behavior of these nutrients in soil...

  18. Natural and experimental poisoning of goats with the pyrrolizidine alkaloid-producing plant Crotalaria retusa L

    Science.gov (United States)

    Crotalaria retusa L. (rattleweed), estimated to contain about 4.96% monocrotaline (MCT) in the seed, was associated with a natural poisoning outbreak in goats. The poisoning was experimentally reproduced by the administration of C. retusa seeds containing approximately 4.49% of MCT. Thus, 1 of 3 goa...

  19. Ideotype population exploration: growth, photosynthesis, and yield components at different planting densities in winter oilseed rape (Brassica napus L.).

    Science.gov (United States)

    Ma, Ni; Yuan, Jinzhan; Li, Ming; Li, Jun; Zhang, Liyan; Liu, Lixin; Naeem, Muhammad Shahbaz; Zhang, Chunlei

    2014-01-01

    Rapeseed is one of the most important edible oil crops in the world and the seed yield has lagged behind the increasing demand driven by population growth. Winter oilseed rape (Brassica napus L.) is widely cultivated with relatively low yield in China, so it is necessary to find the strategies to improve the expression of yield potential. Planting density has great effects on seed yield of crops. Hence, field experiments were conducted in Wuhan in the Yangtze River basin with one conventional variety (Zhongshuang 11, ZS11) and one hybrid variety (Huayouza 9, HYZ9) at five planting densities (27.0×10(4), 37.5×10(4), 48.0×10(4), 58.5×10(4), 69.0×10(4) plants ha(-1)) during 2010-2012 to investigate the yield components. The physiological traits for high-yield and normal-yield populations were measured during 2011-2013. Our results indicated that planting densities of 58.5×10(4) plants ha(-1) in ZS11 and 48.0×10(4) plants ha(-1) in HYZ9 have significantly higher yield compared with the density of 27.0×10(4) plants ha(-1) for both varieties. The ideal silique numbers for ZS11 and HYZ9 were ∼0.9×10(4) (n m(-2)) and ∼1×10(4) (n m(-2)), respectively, and ideal primary branches for ZS11 and HYZ9 were ∼250 (n m(-2)) and ∼300 (n m(-2)), respectively. The highest leaf area index (LAI) and silique wall area index (SAI) was ∼5.0 and 7.0, respectively. Moreover, higher leaf net photosynthetic rate (Pn) and water use efficiency (WUE) were observed in the high-yield populations. A significantly higher level of silique wall photosynthesis and rapid dry matter accumulation were supposed to result in the maximum seed yield. Our results suggest that increasing the planting density within certain range is a feasible approach for higher seed yield in winter rapeseed in China.

  20. Assessing power plant impacts on fish populations at Northeast Utilities sites: winter flounder studies at Millstone Nuclear Power Station

    International Nuclear Information System (INIS)

    Lorda, E.; Danila, D.J.; Miller, J.D.; Bireley, L.E.; Jacobsen, P.M.

    1987-01-01

    An historical view is presented of the various impact assessment approaches used to study the winter flounder, including efforts to identify and quantify compensation and to model its population dynamics. This review illustrates the need for unbiased estimates of basic life history parameters and power plant related mortalities if compensatory mechanisms are to be understood and if impact assessments are to be meaningful. 67 references, 19 figures, 10 tables

  1. Plantes médicinales utilisées par les populations Bassa de la région ...

    African Journals Online (AJOL)

    Une enquête ethnobotanique portant sur un échantillon de 90 ménages a été conduite en juin 2010 dans trois villages de la région de Douala, au Cameroun, afin de recenser les plantes médicinales utilisées par les populations rurales. Elle montre que 48 espèces relevant de 44 genres et de 26 familles sont utilisées dans ...

  2. Experimental research and development of main circulation pump bearings in reactor plants using heavy liquid-metal coolants

    International Nuclear Information System (INIS)

    Zudin, A.; Beznosov, A.; Chernysh, A.; Prikazchikov, G.

    2015-01-01

    At the present time, specialists in Russia are engaged in designing the BREST-OD-300 fast neutron lead-coolant reactor plant. There is currently no experience in designing and operating axial pumps of lead-coolant reactor plants, including one of their major units – bearing unit. Selection and substantiation of operating and structural parameters of plain friction bearings used in main circulation pumps of reactor plants running on heavy liquid-metal coolants are important tasks that are solved at the NNSTU. Development of a feasible procedure for designing bearings and its components operating within the structure of the main circulation pump of a reactor plant running on a heavy liquid-metal coolant as well as guidelines for an optimized structural scheme of such bearings set a goal of performing a range of theoretically-calculated and experimental works. The report contains testing data of a hydrostatic bearing with reciprocal fricative choking tested on the NNSTU FT-4 bench running on a lead coolant within the range of 420-500degC. There have been presented a scheme of a bench for testing a contact friction bearing on a high-temperature coolant and the results of investigation tests of bearings of such type at T = 450 ÷ 500degC. Material of the bearing sleeve is steel 08X18H10T, and a possibility is provided with regard to installation of the bearing sleeves and shaft made of non-metal materials (ceramic materials, silicified graphite, etc.). The presented testing data of plain friction bearings operating in a high-temperature heavy liquid-metal coolant will serve as a ground for making an alternative choice of a plain friction bearing for the main circulation pump of a reactor plant running on a heavy liquid-metal coolant. (author)

  3. Plant Disease Severity Assessment-How Rater Bias, Assessment Method, and Experimental Design Affect Hypothesis Testing and Resource Use Efficiency.

    Science.gov (United States)

    Chiang, Kuo-Szu; Bock, Clive H; Lee, I-Hsuan; El Jarroudi, Moussa; Delfosse, Philippe

    2016-12-01

    The effect of rater bias and assessment method on hypothesis testing was studied for representative experimental designs for plant disease assessment using balanced and unbalanced data sets. Data sets with the same number of replicate estimates for each of two treatments are termed "balanced" and those with unequal numbers of replicate estimates are termed "unbalanced". The three assessment methods considered were nearest percent estimates (NPEs), an amended 10% incremental scale, and the Horsfall-Barratt (H-B) scale. Estimates of severity of Septoria leaf blotch on leaves of winter wheat were used to develop distributions for a simulation model. The experimental designs are presented here in the context of simulation experiments which consider the optimal design for the number of specimens (individual units sampled) and the number of replicate estimates per specimen for a fixed total number of observations (total sample size for the treatments being compared). The criterion used to gauge each method was the power of the hypothesis test. As expected, at a given fixed number of observations, the balanced experimental designs invariably resulted in a higher power compared with the unbalanced designs at different disease severity means, mean differences, and variances. Based on these results, with unbiased estimates using NPE, the recommended number of replicate estimates taken per specimen is 2 (from a sample of specimens of at least 30), because this conserves resources. Furthermore, for biased estimates, an apparent difference in the power of the hypothesis test was observed between assessment methods and between experimental designs. Results indicated that, regardless of experimental design or rater bias, an amended 10% incremental scale has slightly less power compared with NPEs, and that the H-B scale is more likely than the others to cause a type II error. These results suggest that choice of assessment method, optimizing sample number and number of replicate

  4. The control and automation of a complex experimental plant: The Sesta test facility; L`automazione di un impiuanto sperimentale complesso: La stazione di Sesta

    Energy Technology Data Exchange (ETDEWEB)

    Maini, Michele; Prandoni, Walter [ENEL Spa, Cologno Monzese (Italy). Polo Elettrico e Automazione. Unita` Robotica

    1997-05-01

    The running of complex experimental plants in the field of energetic sources involves a strong component of automation. Since they are unique and innovative plants there are not well defined ways to run them. So it is necessary to design the automation each time and then to select the proper resources for the implementation. The plant for the testing of gas turbine components of Sesta is an important example of this type of approach.

  5. Genetic diversity and population structure in Polygonum cespitosum: insights to an ongoing plant invasion.

    Directory of Open Access Journals (Sweden)

    Silvia Matesanz

    Full Text Available Molecular markers can help elucidate how neutral evolutionary forces and introduction history contribute to genetic variation in invaders. We examined genetic diversity, population structure and colonization patterns in the invasive Polygonum cespitosum, a highly selfing, tetraploid Asian annual introduced to North America. We used nine diploidized polymorphic microsatellite markers to study 16 populations in the introduced range (northeastern North America, via the analyses of 516 individuals, and asked the following questions: 1 Do populations have differing levels of within-population genetic diversity? 2 Do populations form distinct genetic clusters? 3 Does population structure reflect either geographic distances or habitat similarities? We found low heterozygosity in all populations, consistent with the selfing mating system of P. cespitosum. Despite the high selfing levels, we found substantial genetic variation within and among P. cespitosum populations, based on the percentage of polymorphic loci, allelic richness, and expected heterozygosity. Inferences from individual assignment tests (Bayesian clustering and pairwise FST values indicated high among-population differentiation, which indicates that the effects of gene flow are limited relative to those of genetic drift, probably due to the high selfing rates and the limited seed dispersal ability of P. cespitosum. Population structure did not reflect a pattern of isolation by distance nor was it related to habitat similarities. Rather, population structure appears to be the result of the random movement of propagules across the introduced range, possibly associated with human dispersal. Furthermore, the high population differentiation, genetic diversity, and fine-scale genetic structure (populations founded by individuals from different genetic sources in the introduced range suggest that multiple introductions to this region may have occurred. High genetic diversity may further

  6. Population genetic structure of rare and endangered plants using molecular markers

    Science.gov (United States)

    Raji, Jennifer; Atkinson, Carter T.

    2013-01-01

    This study was initiated to assess the levels of genetic diversity and differentiation in the remaining populations of Phyllostegia stachyoides and Melicope zahlbruckneri in Hawai`i Volcanoes National Park and determine the extent of gene flow to identify genetically distinct individuals or groups for conservation purposes. Thirty-six Amplified Fragment Length Polymorphic (AFLP) primer combinations generated a total of 3,242 polymorphic deoxyribonucleic acid (DNA) fragments in the P. stachyoides population with a percentage of polymorphic bands (PPB) ranging from 39.3 to 65.7% and 2,780 for the M. zahlbruckneri population with a PPB of 18.8 to 64.6%. Population differentiation (Fst) of AFLP loci between subpopulations of P. stachyoides was low (0.043) across populations. Analysis of molecular variance of P. stachyoides showed that 4% of the observed genetic differentiation occurred between populations in different kīpuka and 96% when individuals were pooled from all kīpuka. Moderate genetic diversity was detected within the M. zahlbruckneri population. Bayesian and multivariate analyses both classified the P. stachyoides and M. zahlbruckneri populations into genetic groups with considerable sub-structuring detected in the P. stachyoides population. The proportion of genetic differentiation among populations explained by geographical distance was estimated by Mantel tests. No spatial correlation was found between genetic and geographic distances in both populations. Finally, a moderate but significant gene flow that could be attributed to insect or bird-mediated dispersal of pollen across the different kīpuka was observed. The results of this study highlight the utility of a multi-allelic DNA-based marker in screening a large number of polymorphic loci in small and closely related endangered populations and revealed the presence of genetically unique groups of individuals in both M. zahlbruckneri and P. stachyoides populations. Based on these findings

  7. Experimental study of drying kinetics by forced convection of aromatic plants

    Energy Technology Data Exchange (ETDEWEB)

    Belghit, A; Boutaleb, B C [Laboratoire de Mecanique des Fluides et Energetique, Marrakech (Morocco). Faculte des Sciences Semlalia; Kouhila, M [Laboratoire d' Energie Solaire, Marrakech (Morocco). Ecole Normale Superieure

    2000-08-01

    This paper has the objectives to determine the isotherms of sorption and the drying kinetics of verbena, which is the most consumed aromatic plant in Morocco. The experiments undertaken consist of examining the effects of drying air velocity, temperature of drying air and air moisture content on the drying kinetics of verbena in a laboratory drying tunnel working by forced convection. The results verified, with good reproducibility, that temperature is the main factor in controlling the rate of drying. The expression of the drying rate is determined empirically from the characteristic curve of drying. (author)

  8. NORM in the vicinity of the thermal power plant 'Nikola Tesla' B - experimental results

    International Nuclear Information System (INIS)

    Kisic, D.; Veselinovic, N.; Tokonami, S.; Celikovic, I.; Stojanovic, Z.; Cuknic, O.; Nemcevic, M.; Simovic, R.; Zunic, Z. S.

    2009-01-01

    The paper deals with the results related to identification of ionizing radiation from natural sources (NORM - Naturally Occurring Radioactive Materials) in the vicinity of the fly ash deposit of Thermal Power Plant 'Nikola Tesla B' (TENT B). The survey included such as follows: determination of distribution of naturally soil occurring gases radon ( 222 Rn) and thoron ( 220 Tn) in the vicinity of TENT B by means of passive discriminative solid state nuclear track detectors (CR 39) at the depth of 80 cm with defining its appropriate GPS coordinates. (author) [sr

  9. Highlighting the Need for Systems-level Experimental Characterization of Plant Metabolic Enzymes

    Directory of Open Access Journals (Sweden)

    Martin Karl Magnus Engqvist

    2016-07-01

    Full Text Available The biology of living organisms is determined by the action and interaction of a large number of individual gene products, each with specific functions. Discovering and annotating the function of gene products is key to our understanding of these organisms. Controlled experiments and bioinformatic predictions both contribute to functional gene annotation. For most species it is difficult to gain an overview of what portion of gene annotations are based on experiments and what portion represent predictions. Here, I survey the current state of experimental knowledge of enzymes and metabolism in Arabidopsis thaliana as well as eleven economically important crops and forestry trees – with a particular focus on reactions involving organic acids in central metabolism. I illustrate the limited availability of experimental data for functional annotation of enzymes in most of these species. Many enzymes involved in metabolism of citrate, malate, fumarate, lactate, and glycolate in crops and forestry trees have not been characterized. Furthermore, enzymes involved in key biosynthetic pathways which shape important traits in crops and forestry trees have not been characterized. I argue for the development of novel high-throughput platforms with which limited functional characterization of gene products can be performed quickly and relatively cheaply. I refer to this approach as systems-level experimental characterization. The data collected from such platforms would form a layer intermediate between bioinformatic gene function predictions and in-depth experimental studies of these functions. Such a data layer would greatly aid in the pursuit of understanding a multiplicity of biological processes in living organisms.

  10. Diversity of endophytic bacterial populations and their interaction with Xylella fastidiosa in citrus plants

    NARCIS (Netherlands)

    Araujo, W.L.; Marcon, J.; jr. Maccheroni, W.; Elsas, van J.D.; Vuurde, van J.W.L.; Azevedo, de J.L.

    2002-01-01

    Citrus variegated chlorosis (CVC) is caused by Xylella fastidiosa, a phytopathogenic bacterium that can infect all Citrus sinensis cultivars. The endophytic bacterial communities of healthy, resistant, and CVC-affected citrus plants were studied by using cultivation as well as

  11. The demographic consequences of mutualism: ants increase host-plant fruit production but not population growth

    Science.gov (United States)

    Kevin Ford; Joshua H. Ness; Judith L. Bronstein; William F. Morris

    2015-01-01

    The impact of mutualists on a partner’s demography depends on how they affect the partner’s multiple vital rates and how those vital rates, in turn, affect population growth. However, mutualism studies rarely measure effects on multiple vital rates or integrate them to assess the ultimate impact on population growth. We used vital rate data, population models and...

  12. Adaptive Transgenerational Plasticity in Plants: Case Studies, Mechanisms, and Implications for Natural Populations

    OpenAIRE

    Herman, Jacob J.; Sultan, Sonia E.

    2011-01-01

    Plants respond to environmental conditions not only by plastic changes to their own development and physiology, but also by altering the phenotypes expressed by their offspring. This transgenerational plasticity was initially considered to entail only negative effects of stressful parental environments, such as production of smaller seeds by resource- or temperature-stressed parent plants, and was therefore viewed as environmental noise. Recent evolutionary ecology studies have shown that in ...

  13. Possible effects of cultivated plants in the development of allergy in population of Sindh, Pakistan

    International Nuclear Information System (INIS)

    Waqar, M.A.; Khan, M.; Hasnain, S.M.

    2010-01-01

    Among the various biological particles, pollen grains and fingal spores stand as the two major factors that can cause asthma and allergic rhinitis. Pollen grains can be released by the domestic plants cultivated in and around as omamentals, on road verges and parklands etc. However. those plants are considered allergenic which are wind pollinated, called anemophilous, and very less attention is paid pollen sensitivity of cultivated plants. The purpose of this publication is to explain the types of flowering plants cultivated in Sindh, their flowering periods and the possibility of their pollen grains to induce IgE mediated hypersensitive reaction in people living in tile selected geographical region. In this survey. we have taken into consideration 60 species of plants that are being cultivated in tile province of Sindh. These species are divided into two major groups: the first group includes allergenic pollen producing species. while the second group included 38 species that are known to be non-allergenic. Our results show that most of the abundantly cultivated plants may be considered as secondary potential allergens and/or occupational or cross-reacting allergens. (author)

  14. Two disjunct Pleistocene populations and anisotropic postglacial expansion shaped the current genetic structure of the relict plant Amborella trichopoda.

    Directory of Open Access Journals (Sweden)

    Rémi Tournebize

    Full Text Available Past climate fluctuations shaped the population dynamics of organisms in space and time, and have impacted their present intra-specific genetic structure. Demo-genetic modelling allows inferring the way past demographic and migration dynamics have determined this structure. Amborella trichopoda is an emblematic relict plant endemic to New Caledonia, widely distributed in the understory of non-ultramafic rainforests. We assessed the influence of the last glacial climates on the demographic history and the paleo-distribution of 12 Amborella populations covering the whole current distribution. We performed coalescent genetic modelling of these dynamics, based on both whole-genome resequencing and microsatellite genotyping data. We found that the two main genetic groups of Amborella were shaped by the divergence of two ancestral populations during the last glacial maximum. From 12,800 years BP, the South ancestral population has expanded 6.3-fold while the size of the North population has remained stable. Recent asymmetric gene flow between the groups further contributed to the phylogeographical pattern. Spatially explicit coalescent modelling allowed us to estimate the location of ancestral populations with good accuracy (< 22 km and provided indications regarding the mid-elevation pathways that facilitated post-glacial expansion.

  15. A geoprocessing model for the selection of populations most affected by diffuse industrial contamination: the case of oil refinery plants

    Directory of Open Access Journals (Sweden)

    Roberto Pasetto

    2013-03-01

    Full Text Available INTRODUCTION. A method to select populations living in areas affected by diffuse environmental contamination is presented, with particular regard to oil refineries, in the Italian context. The reasons to use municipality instead of census tract populations for environment and health small-area studies of contaminated sites are discussed. METHODS. Populations most affected by diffuse environmental contamination are identified through a geoprocessing model. Data from the national census 2001 were used to estimate census tract level populations. A geodatabase was developed using the municipality and census tract layers provided by the Italian National Bureau of Statistics (ISTAT. The orthophotos of the Italian territory - year 2006 - available on the geographic information systems (GIS of the National Cartographic Portal, were considered. The area within 2 km from the plant border was used as an operational definition to identify the area at major contamination. RESULTS. The geoprocessing model architecture is presented. The results of its application to the selection of municipality populations in a case study are shown. CONCLUSIONS. The application of the proposed geoprocessing model, the availability of long time series of mortality and morbidity data, and a quali-quantitative estimate of contamination over time, could allow an appraisal of the health status of populations affected by oil refinery emissions.

  16. Component behaviour in the 700 C power plant. Numerical and experimental investigations

    International Nuclear Information System (INIS)

    Schmidt, Kay H.

    2013-01-01

    Currently martensitic steels are used in fossil fired power plants with maximum working temperatures up to 625 C. These steels do not show the required creep rupture strength at the target temperature of 700 C. For these high temperatures, new materials like the nickel base alloys have to be qualified for power plants services. Originating from the weld of turbine materials, nickel base alloys show outstanding creep rupture strength. An alloy with good prospects out of the material class of the nickel base alloys is Alloy 617 mod. However, this material is expensive due to its high nickel content. Furthermore, the complex machinability of this material leads to an additional increase in expenses. A complete fabrication of the boiler area using Alloy 617 mod is not economically feasible, which means that the usage of this material has to be limited to the temperature weld of 625 C to 700 C. For the boiler area with temperatures below 625 C the well proven 9 % to 12 % Cr-steels, like T/P92 and VM12/VM12-SHC may be used. In the weld of low temperatures up to 525 C the usage of the 2.5 % Cr-steel T/P24 offers numerous advantages, in particular in the fabrication of membrane walls. This material shows good creep properties up to temperatures of 525 C and, for thin walled components, T24 can be welded without post weld heat treatment by using suitable techniques. For a successful design and fabrication of a 700 C fossil fired power plant, appropriate materials have to be qualified. Here, a special focus is set on the creep properties of these materials. The presented work is a significant contribution to the qualification of these materials. First, the materials Alloy 617 mod, T/P92, VM12/VM12-SHC and T24 are briefly introduced and characterized. After this, the materials are investigated in a detailed creep testing program. This program includes investigations on base material, extracted from tubes, pipes and inductive bends of pipes. In addition, crossweld specimens

  17. Nematode community shifts in response to experimental warming and canopy conditions are associated with plant community changes in the temperate-boreal forest ecotone.

    Science.gov (United States)

    Thakur, Madhav Prakash; Reich, Peter B; Fisichelli, Nicholas A; Stefanski, Artur; Cesarz, Simone; Dobies, Tomasz; Rich, Roy L; Hobbie, Sarah E; Eisenhauer, Nico

    2014-06-01

    Global climate warming is one of the key forces driving plant community shifts, such as range shifts of temperate species into boreal forests. As plant community shifts are slow to observe, ecotones, boundaries between two ecosystems, are target areas for providing early evidence of ecological responses to warming. The role of soil fauna is poorly explored in ecotones, although their positive and negative effects on plant species can influence plant community structure. We studied nematode communities in response to experimental warming (ambient, +1.7, +3.4 °C) in soils of closed and open canopy forest in the temperate-boreal ecotone of Minnesota, USA and calculated various established nematode indices. We estimated species-specific coverage of understory herbaceous and shrub plant species from the same experimental plots and tested if changes in the nematode community are associated with plant cover and composition. Individual nematode trophic groups did not differ among warming treatments, but the ratio between microbial-feeding and plant-feeding nematodes increased significantly and consistently with warming in both closed and open canopy areas and at both experimental field sites. The increase in this ratio was positively correlated with total cover of understory plant species, perhaps due to increased predation pressure on soil microorganisms causing higher nutrient availability for plants. Multivariate analyses revealed that temperature treatment, canopy conditions and nematode density consistently shaped understory plant communities across experimental sites. Our findings suggest that warming-induced changes in nematode community structure are associated with shifts in plant community composition and productivity in the temperate-boreal forest ecotones.

  18. Experimental tests performed with liquid waste contained in the tank F-710/D at EUREX plant

    International Nuclear Information System (INIS)

    Gasso, G.; Momo, S.; Pietrelli, L.; Troiani, F.

    1989-11-01

    In this report the result of experimental test performed with real liquid waste earning from reprocessing of MTR nuclear fuel is reported. The aim of the research is to separate the actinides and long-lived radioactive fission products from bulk salt matrix of HLW. Taking into account the chemical and radiochemical composition of the liquid waste, process based on the chemical precipitation and/or adsorption were studied by using the radioactive waste sampled from the tank. The results show that decontamination factors of 100, 1000, 5000 were obtained for Sr, Cs and Pu respectively. (author)

  19. Effect of Varieties and Plant Population Densities on Dry Matter Production, Radiation Interception and Radiation Energy Conversion in Peanut

    Directory of Open Access Journals (Sweden)

    agus suprapto

    2012-05-01

    Full Text Available The solar radiation is one of the major criteria to obtaining advantages on peanuts (Arachishypogaea L.. Although various combinations of crops have been reported, but variety association and plant population densities (PPD during the periodically stage of growth on peanuts have yet to be analyzed. Dry matter production (DM, radiation energy interception, and radiation energy conversions were monitored over the growth period of two varieties of peanut. An experiment was conducted in Jambegede Research Farm, Indonesian Legume and Tuber Crops Research Institute, Malang, East Java, Indonesia, from July until October 2011. The experiment was arranged in a Split Plot Design with three replications. Peanut varieties, as the main plot consisted of two treatments: Kelinci andKancil variety. In addition, five PPD variations as sub plot consisted of 8.1, 11.1, 16.0, 25.0 and 44.4 plant m-2 were arranged in a square spacing. The results showed that DM production from high PPD increased gradually to lower PPD in all varieties. Interception efficiency (IE increased in all varieties from early sowing. A plant population density of 25.0 m-2 and 44.4 plants m-2 intercepted more radiation over 11.1 or 16.0 plants m-2. Conversion efficiency of radiation energy (CE to total dry matter production on Kelinci variety (1.52% indicated a slight higher percentage than on Kancil variety (1.41%. Moreover, the CE and IE values indicated a decrease as the PPD increased on maximum DM.

  20. Experimental study of the radio-active contamination of certain cultivated plants by irrigation water

    International Nuclear Information System (INIS)

    Michon, G.; Fioramonti, S.; Marty, J.R.; Benard, P.; Flanzy, M.; Delas, J.; Delmas, J.; Demias, Ch.; Huguet, C.

    1964-01-01

    This report follows on to the CEA reports no 1860 and 2159 and gives the results obtained during the years 1961 and 1962. These results confirm for the most part those obtained previously and deal also with a larger variety of vegetables. Vines and artificial prairies were also dealt with during the course of this work. The large dispersion of the limiting values of the coefficient r (the ratio between the amount of radio-elements in a kilogram of product harvested, to the amount of radio-elements present in a litre of irrigation water) with different types of soil, different plant types, etc... , makes it impossible to draw any general conclusions. Each case of rejection requires a special study of which the outlive is given. At all events it is to be expected that in the majority of cases these studies will lead to a decrease in the norms now in force. (authors) [fr

  1. Experimental studies of computerized procedures and team size in nuclear power plant operations

    International Nuclear Information System (INIS)

    Huang, F.-H.; Hwang, S.-L.

    2009-01-01

    The operation of a nuclear power plant is so complex that it requires teamwork. To support team performance, a system need to provide all team members integrated information displays as well as decision aids (e.g., computerized procedures). Two experiments were conducted to investigate the effects of computerized procedures and team size on operating performance. Forty-five participants were involved in the experiments. Each participant executed decision and action tasks to deal with alarm signals, while detecting occasional system errors in the interface. Results showed that effects of computerized procedures were significant on various performance indicators, such as operation time, operation errors, and learning effect, and that two operators would be a satisfactory size in the teamwork system providing computerized procedures

  2. Soil microbial community structure is unaltered by plant invasion, vegetation clipping, and nitrogen fertilization in experimental semi-arid grasslands

    Directory of Open Access Journals (Sweden)

    Chelsea J Carey

    2015-05-01

    Full Text Available Global and regional environmental changes often co-occur, creating complex gradients of disturbance on the landscape. Soil microbial communities are an important component of ecosystem response to environmental change, yet little is known about how microbial structure and function respond to multiple disturbances, or whether multiple environmental changes lead to unanticipated interactive effects. Our study used experimental semi-arid grassland plots in a Mediterranean-climate to determine how soil microbial communities in a seasonally variable ecosystem respond to one, two, or three simultaneous environmental changes: exotic plant invasion, plant invasion + vegetation clipping (to simulate common management practices like mowing or livestock grazing, plant invasion + nitrogen (N fertilization, and plant invasion + clipping + N fertilization. We examined microbial community structure 5-6 years after plot establishment via sequencing of >1 million 16S rRNA genes. Abiotic soil properties (soil moisture, temperature, pH, and inorganic N and microbial functioning (nitrification and denitrification potentials were also measured and showed treatment-induced shifts, including altered NO3- availability, temperature, and nitrification potential. Despite these changes, bacterial and archaeal communities showed little variation in composition and diversity across treatments. Even communities in plots exposed to three interacting environmental changes were similar to those in restored native grassland plots. Historical exposure to large seasonal and inter-annual variations in key soil properties, in addition to prior site cultivation, may select for a functionally plastic or largely dormant microbial community, resulting in a microbial community that is structurally robust to single and multiple environmental changes.

  3. The Impact of Different Habitat Conditions on the Variability of Wild Populations of a Medicinal Plant Betonica officinalis L.

    Directory of Open Access Journals (Sweden)

    Kinga Kostrakiewicz-Gierałt

    2015-06-01

    Full Text Available Plants are important source of beneficial bioactive compounds which may find various applications as functional ingredients, such as components of food supplements, cosmetics, and pharmaceuticals. One such medicinal plant is Betonica officinalis, populations of which were investigated in 2012‒13. The studies were conducted in patches of Molinietum caeruleae dominated by: small meadow taxa (patch I; the shrub willow Salix repens ssp. rosmarinifolia (patch II; large tussock grasses Deschampsia caespitosa and Molinia caerulaea (patch III; tall-growing macroforbs Filipendula ulmaria and Solidago canadensis (patch IV. Over successive patches, the average height of plant cover increased, as did soil moisture, while light availability at ground level decreased. Much greater abundance and density of the Betonica officinalis population were found in patches I, III and IV, while lower values for these parameters were noted in patch II. Individuals in pre-reproductive stages were absent during whole study period in all study plots, vegetative ramet clusters were observed in plots situated in patches I and III in the first year of observations, while only generative ramet clusters occurred in plots set in patches II and IV. The number of rosettes per ramet cluster, number and dimensions of rosette leaves, height of flowering stems, number of cauline leaves, length of inflorescences, as well as number and length of flowers increased gradually over successive patches, whereas the number of generative stems per ramet cluster did not differ remarkably among populations. On the basis of the performed studies it might be concluded that the condition of populations deteriorated from patches overgrown by large-tussock grasses and characterized by considerable share of native and alien tall-growing macroforbs, via patch dominated by small meadow taxa, to patch prevailed by shrub willows.

  4. Long-term dim light during nighttime changes activity patterns and space use in experimental small mammal populations.

    Science.gov (United States)

    Hoffmann, Julia; Palme, Rupert; Eccard, Jana Anja

    2018-07-01

    Artificial light at night (ALAN) is spreading worldwide and thereby is increasingly interfering with natural dark-light cycles. Meanwhile, effects of very low intensities of light pollution on animals have rarely been investigated. We explored the effects of low intensity ALAN over seven months in eight experimental bank vole (Myodes glareolus) populations in large grassland enclosures over winter and early breeding season, using LED garden lamps. Initial populations consisted of eight individuals (32 animals per hectare) in enclosures with or without ALAN. We found that bank voles under ALAN experienced changes in daily activity patterns and space use behavior, measured by automated radiotelemetry. There were no differences in survival and body mass, measured with live trapping, and none in levels of fecal glucocorticoid metabolites. Voles in the ALAN treatment showed higher activity at night during half moon, and had larger day ranges during new moon. Thus, even low levels of light pollution as experienced in remote areas or by sky glow can lead to changes in animal behavior and could have consequences for species interactions. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. EEG Analysis during complex diagnostic tasks in Nuclear Power Plants - Simulator-based Experimental Study

    International Nuclear Information System (INIS)

    Ha, Jun Su; Seong, Poong Hyun

    2005-01-01

    In literature, there are a lot of studies based on EEG signals during cognitive activities of human-beings but most of them dealt with simple cognitive activities such as transforming letters into Morse code, subtraction, reading, semantic memory search, visual search, memorizing a set of words and so on. In this work, EEG signals were analyzed during complex diagnostic tasks in NPP simulator-based environment. Investigated are the theta, alpha, beta, and gamma band EEG powers during the diagnostic tasks. The experimental design and procedure are represented in section 2 and the results are shown in section 3. Finally some considerations are discussed and the direction for the further work is proposed in section 4

  6. EEG Analysis during complex diagnostic tasks in Nuclear Power Plants - Simulator-based Experimental Study

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Jun Su; Seong, Poong Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    2005-07-01

    In literature, there are a lot of studies based on EEG signals during cognitive activities of human-beings but most of them dealt with simple cognitive activities such as transforming letters into Morse code, subtraction, reading, semantic memory search, visual search, memorizing a set of words and so on. In this work, EEG signals were analyzed during complex diagnostic tasks in NPP simulator-based environment. Investigated are the theta, alpha, beta, and gamma band EEG powers during the diagnostic tasks. The experimental design and procedure are represented in section 2 and the results are shown in section 3. Finally some considerations are discussed and the direction for the further work is proposed in section 4.

  7. The Italian R and D and industrial program for an accelerator driven system experimental plant

    International Nuclear Information System (INIS)

    Carta, M.; Gherardi, G.; Buono, S.; Cinotti, L.

    2001-01-01

    Accelerator Driven Systems (ADS), coupling an accelerator with a target and a sub-critical reactor, could simultaneously burn minor actinides and transmute long-lived fission products, while producing a consistent amount of electrical energy. A team of Italian R and D organizations and industries has set up a network of coordinated programs addressed to study the design issues of an 80 MW th Experimental Facility. The present memo focalizes the attention on some results obtained by the R and D activities and by the ongoing industrial short term activities aiming at the preparation of the proposed preliminary design, leaving the deal to define the details of the subsequent medium term activities to the expected common program in the European context. (author)

  8. Experimental study on dynamic pipe fracture in consideration of hydropower plant model

    Directory of Open Access Journals (Sweden)

    Kazumi Ishikawa

    2009-12-01

    Full Text Available In the case of sudden valve closure, water hammer creates the most powerful pressure and damage to pipeline systems. The best way to protect the pipeline system is to eliminate water hammer. The main reasons for water hammer occurrence are valve closure, high initial velocity, and static pressure. However, it is difficult to eliminate water hammer. Water hammer tends to occur when the valve is being closed. In this study, the pipe fracture caused by static water pressure, gradually increasing pressure, and suddenly increasing pressure were compared experimentally in a breaking PVC test pipe. The quasi-static zone, the dynamic zone, and the transition zone are defined through the results of those experiments, with consideration of the fracture patterns of test pipes and impulses. The maximum pressure results were used to design the pipeline even though it is in the dynamic zone.

  9. Experimental investigation of the ORC system in a cogenerative domestic power plant with a scroll expanders

    Science.gov (United States)

    Kaczmarczyk, Tomasz Z.; Ihnatowicz, Eugeniusz; Żywica, Grzegorz; Kiciński, Jan

    2015-11-01

    The paper presents the results of experimental investigations of the ORC system with two scroll expanders which have been used as a source of electricity. Theworking fluidwas HFE7100 - a newly engineered fluid with a unique heat transfer and favourable environmental properties. In the ORC system three heat exchangers were used (evaporator, regenerator, condenser) and before expanders the droplet separator was installed. As a source of heat an innovative biomass boiler was used. Studies have been carried out for the expanders worked in series and in parallel. The paper presents the thermal and fluidflow properties of the ORC installation for the selected flow rates and different temperatures of the working medium. The characteristics of output electrical power, operating speed and vibrations for scroll expanders were also presented.

  10. Experimental study of radioactive aerosols in the vicinity of the Chernobyl Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Boulyga, S.F.; Lomonosova, E.M.; Zhuk, I.V.; Yaroshevich, O.I.; Kudrjashov, V.P.; Mironov, V.P

    1999-12-01

    Study of radioactive aerosols in the relocation zone and in the populated areas have been carried out for a number of years. The experiments on modelling resuspension were performed while conducting agricultural work. Nuclear track radiography and alpha spectrometry with radiochemical extraction of plutonium were used as analytical methods for the determination of the transuranium elements contents. The distributions of radioactive particles were obtained as to activity and sizes. Specific activity of 'hot particles' increases with decreasing diameter. In aerosols selected at a distance of more than 10 km from the Chernobyl NPP pure fuel particles with sizes of more than 5 {mu}m were not found. The activity of the finely dispersed fraction of aerosols, which is more dangerous when inhaled by the organism, is comparable with a total activity of large particles.

  11. Experimental study of radioactive aerosols in the vicinity of the Chernobyl Nuclear Power Plant

    International Nuclear Information System (INIS)

    Boulyga, S.F.; Lomonosova, E.M.; Zhuk, I.V.; Yaroshevich, O.I.; Kudrjashov, V.P.; Mironov, V.P.

    1999-01-01

    Study of radioactive aerosols in the relocation zone and in the populated areas have been carried out for a number of years. The experiments on modelling resuspension were performed while conducting agricultural work. Nuclear track radiography and alpha spectrometry with radiochemical extraction of plutonium were used as analytical methods for the determination of the transuranium elements contents. The distributions of radioactive particles were obtained as to activity and sizes. Specific activity of 'hot particles' increases with decreasing diameter. In aerosols selected at a distance of more than 10 km from the Chernobyl NPP pure fuel particles with sizes of more than 5 μm were not found. The activity of the finely dispersed fraction of aerosols, which is more dangerous when inhaled by the organism, is comparable with a total activity of large particles

  12. Analysis of organic pollutants in the soils of the disused gas plants. Experimental evaluation and recommendations

    International Nuclear Information System (INIS)

    Caron, S.; Carmant, S.

    1997-01-01

    In France, environmental investigations are at the moment carried out on numerous disused gas plants sites, which soils can have been polluted by the by-products generated during the fabrication of the gas (most of the time coal tar). Within the context of those investigations, diagnosis of the pollution of soils by the analytical way is an essential operation on the basis of which the risks are evaluated and the treatments are decided. Moreover, the evolution of the pollution level during the cleaning up of the soils and the efficiency of the treatment can only be measured by the analytical way. Until today, analytical aspects, relative to the study of polluted soils can be discussed. Indeed, in consideration of the heterogeneity of the soils, there are difficulties, on the first hand on sites during the sampling of the soils, on the other hand in the laboratory during the chemical analysis of the organic pollutants. After having evoked this problematic, the paper accounts for the evaluation, done by GDF, of varied analytical methods, used and even recommended by reference oragnizations (included: preparatation of the samples, extraction of the organic pollutants, analysis of the extract and interpretation). Finally, on the basis of the accumulated experinece, some advice are given on how to optimize the number and the kind of samples as well as the combined analysis. (au)

  13. An experimental and analytical investigation of water chillers of nuclear power plant

    International Nuclear Information System (INIS)

    Wang Chunming

    2005-01-01

    Water chillers are important components of the electric building chilled water system of Nuclear Power Plant. In this article, we describe the seismic qualification methodology. A united method of seismic analysis and experiment testing were applied. Since the seismic classification of the evaporator, condenser and oil separator is 1F, the function criteria are necessary to be satisfied. The functional and performance of the control panel were qualified by seismic test. In order to get the seismic time histories of the base of the motor, compressor and control panel, we did time histories analysis for the whole chillers using the seismic acceleration time history of the building floor on which the water chillers was located. Then, these curves were translated into required response spectrum (RRS), which were used by the seismic test of water chillers compressor sets. All passive components, such as evaporator, condenser, oil separator and support, were qualified by seismic stress analysis method. These components were verified to satisfy the standard when they were subjected to the seismic, gravitational, operational pressure and nozzle loads. The Chillers' components were qualified to the specification and the standard. The motor-compressor set and control panel were qualified to the functional and performance criteria. The applied of this methodology adequately qualified the function of the water chillers compressor sets , especially after the aging test. (authors)

  14. Experimental coal dust suppression system installed at the Nikola Tesla thermal power plant

    Energy Technology Data Exchange (ETDEWEB)

    Guzijan, D [Rudarski Institut, Belgrade (Yugoslavia). Zavod za Ventilaciju i Tehnicku Zastitu

    1988-01-01

    Describes a project conducted at the Nikola Tesla thermal power plant by the Mining Institute of Belgrade to reduce the high levels of dust concentrations in overloading stations on coal conveyors and hoppers. A mathematical model was developed to determine the ventilation capacity required at each of the 18 overloading stations with the hoppers considered successively: empty, 1/3 full, 2/3 full and completely full. Shows how this model enabled an efficient dust suppression system to be developed and subsequently installed by the Termovent company in Belgrade using 4 axial ventilators supplied by the Ventilator Company in Zagreb. The ventilators were powered by means of 5.5 kW electric motors and provided 440 Pa pressure at 950 rpm. Gives the result of dust concentration measurements indicating that the installed system achieved the results predicted by the mathematical model and that the levels were well below the statutory limit. A description of the complete installation is included. 3 refs.

  15. Mercury Speciation in Coal-Fired Power Plant Flue Gas-Experimental Studies and Model Development

    Energy Technology Data Exchange (ETDEWEB)

    Radisav Vidic; Joseph Flora; Eric Borguet

    2008-12-31

    The overall goal of the project was to obtain a fundamental understanding of the catalytic reactions that are promoted by solid surfaces present in coal combustion systems and develop a mathematical model that described key phenomena responsible for the fate of mercury in coal-combustion systems. This objective was achieved by carefully combining laboratory studies under realistic process conditions using simulated flue gas with mathematical modeling efforts. Laboratory-scale studies were performed to understand the fundamental aspects of chemical reactions between flue gas constituents and solid surfaces present in the fly ash and their impact on mercury speciation. Process models were developed to account for heterogeneous reactions because of the presence of fly ash as well as the deliberate addition of particles to promote Hg oxidation and adsorption. Quantum modeling was used to obtain estimates of the kinetics of heterogeneous reactions. Based on the initial findings of this study, additional work was performed to ascertain the potential of using inexpensive inorganic sorbents to control mercury emissions from coal-fired power plants without adverse impact on the salability fly ash, which is one of the major drawbacks of current control technologies based on activated carbon.

  16. Soil to plant transfer of 134Cs for olive and orange trees after four years' experimentation

    International Nuclear Information System (INIS)

    Skarlou, V.; Nobeli, C.; Anoussis, J.; Haidouti, C.

    1998-01-01

    The transfer parameters of 134 Cs from soil to tree crops (olive and orange trees) were calculated within a long-term glass-house pot experiment which was started in 1994. The effect of the soil characteristics on 134 Cs uptake was also studied using two soils with different physical and chemical properties. Both evergreen trees exhibited a similar behavior in the two soils, showing that a higher or lower uptake is not crop specific. The capacity of the trees for 134 Cs absorption through the roots seems to be significantly influenced by the soil type. The transfer factors were very low in the calcareous heavy soil and much higher in the acid light soil (up to 10 times for olives and 40 for the edible part of oranges). The difference in the TFs is higher between the two soils than between the two tree species. 134 Cs concentration kept increasing in the orange trees up to the 4th year of growth, while it seems to reach an equilibrium, with no further increase, in the olive trees. Although the behavior of the two tree species is similar, the difference in the final processed product is extreme. A significant amount of 134 Cs was observed in olives grown in the light-acid soil whereas no transfer to the olive oil was detected. On the other hand, the edible part of the oranges showed the highest 134 Cs of nearly all the plant parts

  17. The demography of climate-driven and density-regulated population dynamics in a perennial plant

    DEFF Research Database (Denmark)

    Dahlgren, Johan; Bengstsson, Karin; Ehrlén, Johan

    2016-01-01

    Identifying the internal and external drivers of population dynamics is a key objective in ecology, currently accentuated by the need to forecast the effects of climate change on species distributions and abundances. The interplay between environmental and density effects is one particularly...... important aspect of such forecasts. We examined the simultaneous impact of climate and intraspecific density on vital rates of the dwarf shrub Fumana procumbens over 20 yr, using generalized additive mixed models. We then analyzed effects on population dynamics using integral projection models...... to be driven solely by the environment can overestimate extinction risks if there is density dependence. We conclude that density regulation can dampen effects of climate change on Fumana population size, and discuss the need to quantify density dependence in predictions of population responses...

  18. Possible accidents in nuclear power plants and their effect on the population

    International Nuclear Information System (INIS)

    Loester, W.

    1981-01-01

    Besides giving a classification of accidents (disturbance, maximum accident considered, uncontrollable superaccident), the paper assesses the activities released, contamination values, dose-limits for first-aid ponnel and for the radiation exposure of the population. (DG) [de