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Sample records for surrogate species chemical

  1. Progress in Chemical Kinetic Modeling for Surrogate Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Pitz, W J; Westbrook, C K; Herbinet, O; Silke, E J

    2008-06-06

    Gasoline, diesel, and other alternative transportation fuels contain hundreds to thousands of compounds. It is currently not possible to represent all these compounds in detailed chemical kinetic models. Instead, these fuels are represented by surrogate fuel models which contain a limited number of representative compounds. We have been extending the list of compounds for detailed chemical models that are available for use in fuel surrogate models. Detailed models for components with larger and more complicated fuel molecular structures are now available. These advancements are allowing a more accurate representation of practical and alternative fuels. We have developed detailed chemical kinetic models for fuels with higher molecular weight fuel molecules such as n-hexadecane (C16). Also, we can consider more complicated fuel molecular structures like cyclic alkanes and aromatics that are found in practical fuels. For alternative fuels, the capability to model large biodiesel fuels that have ester structures is becoming available. These newly addressed cyclic and ester structures in fuels profoundly affect the reaction rate of the fuel predicted by the model. Finally, these surrogate fuel models contain large numbers of species and reactions and must be reduced for use in multi-dimensional models for spark-ignition, HCCI and diesel engines.

  2. TOXICITY OF PENTACHLOROPHENOL TO ENDANGERED AND SURROGATE FISH SPECIES

    Science.gov (United States)

    Water quality criteria (WQC) generally are based on the responses of easily cultured and tested surrogate species. Little is known about the relative sensitivity of surrogate and endangered species. The objective of this study was to compare acute and chronic (early life-stage) ...

  3. SURROGATE SPECIES IN ASSESSING CONTAMINANT RISK FOR ENDANGERED FISHES

    Science.gov (United States)

    Rainbow trout, fathead minnows, and sheepshead minnows were tested as surrogate species to assess contaminant risk for 17 endangered fishes and one toad species. Acute toxicity tests were conducted with carbaryl, copper, 4-nonylphenol, pentachlorophenol, and permethrin in accord...

  4. A computational methodology for formulating gasoline surrogate fuels with accurate physical and chemical kinetic properties

    KAUST Repository

    Ahmed, Ahfaz

    2015-03-01

    Gasoline is the most widely used fuel for light duty automobile transportation, but its molecular complexity makes it intractable to experimentally and computationally study the fundamental combustion properties. Therefore, surrogate fuels with a simpler molecular composition that represent real fuel behavior in one or more aspects are needed to enable repeatable experimental and computational combustion investigations. This study presents a novel computational methodology for formulating surrogates for FACE (fuels for advanced combustion engines) gasolines A and C by combining regression modeling with physical and chemical kinetics simulations. The computational methodology integrates simulation tools executed across different software platforms. Initially, the palette of surrogate species and carbon types for the target fuels were determined from a detailed hydrocarbon analysis (DHA). A regression algorithm implemented in MATLAB was linked to REFPROP for simulation of distillation curves and calculation of physical properties of surrogate compositions. The MATLAB code generates a surrogate composition at each iteration, which is then used to automatically generate CHEMKIN input files that are submitted to homogeneous batch reactor simulations for prediction of research octane number (RON). The regression algorithm determines the optimal surrogate composition to match the fuel properties of FACE A and C gasoline, specifically hydrogen/carbon (H/C) ratio, density, distillation characteristics, carbon types, and RON. The optimal surrogate fuel compositions obtained using the present computational approach was compared to the real fuel properties, as well as with surrogate compositions available in the literature. Experiments were conducted within a Cooperative Fuels Research (CFR) engine operating under controlled autoignition (CAI) mode to compare the formulated surrogates against the real fuels. Carbon monoxide measurements indicated that the proposed surrogates

  5. Evaluation and Development of Chemical Kinetic Mechanism Reduction Scheme for Biodiesel and Diesel Fuel Surrogates

    DEFF Research Database (Denmark)

    Poon, Hiew Mun; Ng, Hoon Kiat; Gan, Suyin

    2013-01-01

    The aim of this study is to evaluate the existing chemical kinetic mechanism reduction techniques. From here, an appropriate reduction scheme was developed to create compact yet comprehensive surrogate models for both diesel and biodiesel fuels for diesel engine applications. The reduction...... techniques applied here were Directed Relation Graph (DRG), DRG with Error Propagation, DRG-aided Sensitivity Analysis, and DRG with Error Propagation and Sensitivity Analysis. Nonetheless, the reduced mechanisms generated via these techniques were not sufficiently small for application in multi......-dimensional computational fluid dynamics (CFD) study. A new reduction scheme was therefore formulated. A 68-species mechanism for biodiesel surrogate and a 49-species mechanism for diesel surrogate were successfully derived from the respective detailed mechanisms. An overall 97% reduction in species number...

  6. Diesel Surrogate Fuels for Engine Testing and Chemical-Kinetic Modeling: Compositions and Properties.

    Science.gov (United States)

    Mueller, Charles J; Cannella, William J; Bays, J Timothy; Bruno, Thomas J; DeFabio, Kathy; Dettman, Heather D; Gieleciak, Rafal M; Huber, Marcia L; Kweon, Chol-Bum; McConnell, Steven S; Pitz, William J; Ratcliff, Matthew A

    2016-02-18

    The primary objectives of this work were to formulate, blend, and characterize a set of four ultralow-sulfur diesel surrogate fuels in quantities sufficient to enable their study in single-cylinder-engine and combustion-vessel experiments. The surrogate fuels feature increasing levels of compositional accuracy (i.e., increasing exactness in matching hydrocarbon structural characteristics) relative to the single target diesel fuel upon which the surrogate fuels are based. This approach was taken to assist in determining the minimum level of surrogate-fuel compositional accuracy that is required to adequately emulate the performance characteristics of the target fuel under different combustion modes. For each of the four surrogate fuels, an approximately 30 L batch was blended, and a number of the physical and chemical properties were measured. This work documents the surrogate-fuel creation process and the results of the property measurements.

  7. Incorporating surrogate species and seascape connectivity to improve marine conservation outcomes.

    Science.gov (United States)

    Olds, Andrew D; Connolly, Rod M; Pitt, Kylie A; Maxwell, Paul S; Aswani, Shankar; Albert, Simon

    2014-08-01

    Conservation focuses on maintaining biodiversity and ecosystem functioning, but gaps in our knowledge of species biology and ecological processes often impede progress. For this reason, focal species and habitats are used as surrogates for multispecies conservation, but species-based approaches are not widely adopted in marine ecosystems. Reserves in the Solomon Islands were designed on the basis of local ecological knowledge to conserve bumphead parrotfish (Bolbometopon muricatum) and to protect food security and ecosystem functioning. Bumphead parrotfish are an iconic threatened species and may be a useful surrogate for multispecies conservation. They move across tropical seascapes throughout their life history, in a pattern of habitat use that is shared with many other species. We examined their value as a conservation surrogate and assessed the importance of seascape connectivity (i.e., the physical connectedness of patches in the seascape) among reefs, mangroves, and seagrass to marine reserve performance. Reserves were designed for bumphead parrotfish, but also enhanced the abundance of other species. Integration of local ecological knowledge and seascape connectivity enhanced the abundance of 17 other harvested fish species in local reserves. This result has important implications for ecosystem functioning and local villagers because many of these species perform important ecological processes and provide the foundation for extensive subsistence fisheries. Our findings suggest greater success in maintaining and restoring marine ecosystems may be achieved when they are managed to conserve surrogate species and preserve functional seascape connections. © 2014 Society for Conservation Biology.

  8. Higher taxa as surrogates of species richness of spiders in insect-resistant transgenic rice

    Institute of Scientific and Technical Information of China (English)

    Sheng Lin; Min-Sheng You; Liette Vasseur; Guang Yang; Feng-Jing Liu; Feng Guo

    2012-01-01

    Biodiversity assessments can often be time- and resource-consuming.Several alternative approaches have been proposed to reduce sampling efforts,including indicator taxa and surrogates.In this study,we examine the reliability of higher taxon surrogates to predict species richness in two experimental rice fields of Fujian Province,southeastern China during 2005 and 2009.Spider samples in transgenic and nontransgenic plots were collected using a suction sampler.Both the genus and family surrogates had significant and positive linear relationships with species richness in the transgenic and nontransgenic rice fields.The rice varieties did not significantly influence the linear relationships.Our findings suggest that higher-taxon surrogacy could be a useful alternative to complete species inventory for risk assessments of transgenic rice.

  9. Evaluating β Diversity as a Surrogate for Species Representation at Fine Scale.

    Directory of Open Access Journals (Sweden)

    Paul Beier

    Full Text Available Species turnover or β diversity is a conceptually attractive surrogate for conservation planning. However, there has been only 1 attempt to determine how well sites selected to maximize β diversity represent species, and that test was done at a scale too coarse (2,500 km2 sites to inform most conservation decisions. We used 8 plant datasets, 3 bird datasets, and 1 mammal dataset to evaluate whether sites selected to span β diversity will efficiently represent species at finer scale (sites sizes < 1 ha to 625 km2. We used ordinations to characterize dissimilarity in species assemblages (β diversity among plots (inventory data or among grid cells (atlas data. We then selected sites to maximize β diversity and used the Species Accumulation Index, SAI, to evaluate how efficiently the surrogate (selecting sites for maximum β diversity represented species in the same taxon. Across all 12 datasets, sites selected for maximum β diversity represented species with a median efficiency of 24% (i.e., the surrogate was 24% more effective than random selection of sites, and an interquartile range of 4% to 41% efficiency. β diversity was a better surrogate for bird datasets than for plant datasets, and for atlas datasets with 10-km to 14-km grid cells than for atlas datasets with 25-km grid cells. We conclude that β diversity is more than a mere descriptor of how species are distributed on the landscape; in particular β diversity might be useful to maximize the complementarity of a set of sites. Because we tested only within-taxon surrogacy, our results do not prove that β diversity is useful for conservation planning. But our results do justify further investigation to identify the circumstances in which β diversity performs well, and to evaluate it as a cross-taxon surrogate.

  10. Separation of chemical species

    International Nuclear Information System (INIS)

    Rentzepis, P.M.

    1977-01-01

    Isotopic separation is accomplished by (1) a second photon irradiation step for selective ionization of a first isotopic species and (2) selective precipitation of a generally immiscible liquid from the saturating vapor phase on the ionized species. The first photon corresponds with a sharply defined spectral portion of the irradiation which exclusively excites the first species to a vibrational level. The second photon further excites this species to its ionization level. Selective precipitation is by coulombic attraction between the ionized species and the vapor. The procedure is applicable to any vapor phase ionizable material

  11. Reduced Gasoline Surrogate (Toluene/n-Heptane/iso-Octane) Chemical Kinetic Model for Compression Ignition Simulations

    KAUST Repository

    Sarathy, Mani

    2018-04-03

    Toluene primary reference fuel (TPRF) (mixture of toluene, iso-octane and heptane) is a suitable surrogate to represent a wide spectrum of real fuels with varying octane sensitivity. Investigating different surrogates in engine simulations is a prerequisite to identify the best matching mixture. However, running 3D engine simulations using detailed models is currently impossible and reduction of detailed models is essential. This work presents an AramcoMech reduced kinetic model developed at King Abdullah University of Science and Technology (KAUST) for simulating complex TPRF surrogate blends. A semi-decoupling approach was used together with species and reaction lumping to obtain a reduced kinetic model. The model was widely validated against experimental data including shock tube ignition delay times and premixed laminar flame speeds. Finally, the model was utilized to simulate the combustion of a low reactivity gasoline fuel under partially premixed combustion conditions.

  12. Reduced Gasoline Surrogate (Toluene/n-Heptane/iso-Octane) Chemical Kinetic Model for Compression Ignition Simulations

    KAUST Repository

    Sarathy, Mani; Atef, Nour; Alfazazi, Adamu; Badra, Jihad; Zhang, Yu; Tzanetakis, Tom; Pei, Yuanjiang

    2018-01-01

    Toluene primary reference fuel (TPRF) (mixture of toluene, iso-octane and heptane) is a suitable surrogate to represent a wide spectrum of real fuels with varying octane sensitivity. Investigating different surrogates in engine simulations is a prerequisite to identify the best matching mixture. However, running 3D engine simulations using detailed models is currently impossible and reduction of detailed models is essential. This work presents an AramcoMech reduced kinetic model developed at King Abdullah University of Science and Technology (KAUST) for simulating complex TPRF surrogate blends. A semi-decoupling approach was used together with species and reaction lumping to obtain a reduced kinetic model. The model was widely validated against experimental data including shock tube ignition delay times and premixed laminar flame speeds. Finally, the model was utilized to simulate the combustion of a low reactivity gasoline fuel under partially premixed combustion conditions.

  13. An empirical assessment and comparison of species-based and habitat-based surrogates: a case study of forest vertebrates and large old trees.

    Science.gov (United States)

    Lindenmayer, David B; Barton, Philip S; Lane, Peter W; Westgate, Martin J; McBurney, Lachlan; Blair, David; Gibbons, Philip; Likens, Gene E

    2014-01-01

    A holy grail of conservation is to find simple but reliable measures of environmental change to guide management. For example, particular species or particular habitat attributes are often used as proxies for the abundance or diversity of a subset of other taxa. However, the efficacy of such kinds of species-based surrogates and habitat-based surrogates is rarely assessed, nor are different kinds of surrogates compared in terms of their relative effectiveness. We use 30-year datasets on arboreal marsupials and vegetation structure to quantify the effectiveness of: (1) the abundance of a particular species of arboreal marsupial as a species-based surrogate for other arboreal marsupial taxa, (2) hollow-bearing tree abundance as a habitat-based surrogate for arboreal marsupial abundance, and (3) a combination of species- and habitat-based surrogates. We also quantify the robustness of species-based and habitat-based surrogates over time. We then use the same approach to model overall species richness of arboreal marsupials. We show that a species-based surrogate can appear to be a valid surrogate until a habitat-based surrogate is co-examined, after which the effectiveness of the former is lost. The addition of a species-based surrogate to a habitat-based surrogate made little difference in explaining arboreal marsupial abundance, but altered the co-occurrence relationship between species. Hence, there was limited value in simultaneously using a combination of kinds of surrogates. The habitat-based surrogate also generally performed significantly better and was easier and less costly to gather than the species-based surrogate. We found that over 30 years of study, the relationships which underpinned the habitat-based surrogate generally remained positive but variable over time. Our work highlights why it is important to compare the effectiveness of different broad classes of surrogates and identify situations when either species- or habitat-based surrogates are likely

  14. Chloramine demand estimation using surrogate chemical and microbiological parameters.

    Science.gov (United States)

    Moradi, Sina; Liu, Sanly; Chow, Christopher W K; van Leeuwen, John; Cook, David; Drikas, Mary; Amal, Rose

    2017-07-01

    A model is developed to enable estimation of chloramine demand in full scale drinking water supplies based on chemical and microbiological factors that affect chloramine decay rate via nonlinear regression analysis method. The model is based on organic character (specific ultraviolet absorbance (SUVA)) of the water samples and a laboratory measure of the microbiological (F m ) decay of chloramine. The applicability of the model for estimation of chloramine residual (and hence chloramine demand) was tested on several waters from different water treatment plants in Australia through statistical test analysis between the experimental and predicted data. Results showed that the model was able to simulate and estimate chloramine demand at various times in real drinking water systems. To elucidate the loss of chloramine over the wide variation of water quality used in this study, the model incorporates both the fast and slow chloramine decay pathways. The significance of estimated fast and slow decay rate constants as the kinetic parameters of the model for three water sources in Australia was discussed. It was found that with the same water source, the kinetic parameters remain the same. This modelling approach has the potential to be used by water treatment operators as a decision support tool in order to manage chloramine disinfection. Copyright © 2017. Published by Elsevier B.V.

  15. Surrogate models and optimal design of experiments for chemical kinetics applications

    KAUST Repository

    Bisetti, Fabrizio

    2015-01-07

    Kinetic models for reactive flow applications comprise hundreds of reactions describing the complex interaction among many chemical species. The detailed knowledge of the reaction parameters is a key component of the design cycle of next-generation combustion devices, which aim at improving conversion efficiency and reducing pollutant emissions. Shock tubes are a laboratory scale experimental configuration, which is widely used for the study of reaction rate parameters. Important uncertainties exist in the values of the thousands of parameters included in the most advanced kinetic models. This talk discusses the application of uncertainty quantification (UQ) methods to the analysis of shock tube data as well as the design of shock tube experiments. Attention is focused on a spectral framework in which uncertain inputs are parameterized in terms of canonical random variables, and quantities of interest (QoIs) are expressed in terms of a mean-square convergent series of orthogonal polynomials acting on these variables. We outline the implementation of a recent spectral collocation approach for determining the unknown coefficients of the expansion, namely using a sparse, adaptive pseudo-spectral construction that enables us to obtain surrogates for the QoIs accurately and efficiently. We first discuss the utility of the resulting expressions in quantifying the sensitivity of QoIs to uncertain inputs, and in the Bayesian inference key physical parameters from experimental measurements. We then discuss the application of these techniques to the analysis of shock-tube data and the optimal design of shock-tube experiments for two key reactions in combustion kinetics: the chain-brancing reaction H + O2 ←→ OH + O and the reaction of Furans with the hydroxyl radical OH.

  16. Selecting a Conservation Surrogate Species for Small Fragmented Habitats Using Ecological Niche Modelling

    Directory of Open Access Journals (Sweden)

    K. Anne-Isola Nekaris

    2015-01-01

    Full Text Available Flagship species are traditionally large, charismatic animals used to rally conservation efforts. Accepted flagship definitions suggest they need only fulfil a strategic role, unlike umbrella species that are used to shelter cohabitant taxa. The criteria used to select both flagship and umbrella species may not stand up in the face of dramatic forest loss, where remaining fragments may only contain species that do not suit either set of criteria. The Cinderella species concept covers aesthetically pleasing and overlooked species that fulfil the criteria of flagships or umbrellas. Such species are also more likely to occur in fragmented habitats. We tested Cinderella criteria on mammals in the fragmented forests of the Sri Lankan Wet Zone. We selected taxa that fulfilled both strategic and ecological roles. We created a shortlist of ten species, and from a survey of local perceptions highlighted two finalists. We tested these for umbrella characteristics against the original shortlist, utilizing Maximum Entropy (MaxEnt modelling, and analysed distribution overlap using ArcGIS. The criteria highlighted Loris tardigradus tardigradus and Prionailurus viverrinus as finalists, with the former having highest flagship potential. We suggest Cinderella species can be effective conservation surrogates especially in habitats where traditional flagship species have been extirpated.

  17. Evaluation of the toxic properties of naturally weathered Exxon Valdez crude oil to surrogate wildlife species

    International Nuclear Information System (INIS)

    Stubblefield, W.A.; Hancock, G.A.; Ford, W.H.; Prince, H.H.; Ringer, R.K.

    1995-01-01

    The toxic properties of naturally weathered Exxon Valdez crude oil (WEVC) to avian and mammalian wildlife species were evaluated using the surrogate species, mallard duck, Anas platyrhynchos, and European ferret, Mustela putorius. This study was conducted to evaluate the potential for toxic (rather than physical) injury to wildlife species that may have been exposed to WEVC, either through external contact or through dietary uptake. Previous studies have assessed the toxicity of unweathered crude oils, including Alaska North Slope Crude, but little information exists regarding the toxicity of a naturally weathered crude oil, typical of that encountered following a spill. A battery of laboratory toxicity tests was conducted, in compliance with standard and published test procedures, to evaluate acute and subchronic toxicity of WEVC. These included tests of food avoidance, reproductive effects, and direct eggshell application toxicity. Naturally weathered EVC, recovered postspill from Prince William Sound, was used as the test material. 36 refs., 7 figs., 4 tabs

  18. Destruction of chemical warfare surrogates using a portable atmospheric pressure plasma jet

    Science.gov (United States)

    Škoro, Nikola; Puač, Nevena; Živković, Suzana; Krstić-Milošević, Dijana; Cvelbar, Uroš; Malović, Gordana; Petrović, Zoran Lj.

    2018-01-01

    Today's reality is connected with mitigation of threats from the new chemical and biological warfare agents. A novel investigation of cold plasmas in contact with liquids presented in this paper demonstrated that the chemically reactive environment produced by atmospheric pressure plasma jet (APPJ) is potentially capable of rapid destruction of chemical warfare agents in a broad spectrum. The decontamination of three different chemical warfare agent surrogates dissolved in liquid is investigated by using an easily transportable APPJ. The jet is powered by a kHz signal source connected to a low-voltage DC source and with He as working gas. The detailed investigation of electrical properties is performed for various plasmas at different distances from the sample. The measurements of plasma properties in situ are supported by the optical spectrometry measurements, whereas the high performance liquid chromatography measurements before and after the treatment of aqueous solutions of Malathion, Fenitrothion and Dimethyl Methylphosphonate. These solutions are used to evaluate destruction and its efficiency for specific neural agent simulants. The particular removal rates are found to be from 56% up to 96% during 10 min treatment. The data obtained provide basis to evaluate APPJ's efficiency at different operating conditions. The presented results are promising and could be improved with different operating conditions and optimization of the decontamination process.

  19. Chemical Kinetic Insights into the Octane Number and Octane Sensitivity of Gasoline Surrogate Mixtures

    KAUST Repository

    Singh, Eshan

    2017-02-01

    Gasoline octane number is a significant empirical parameter for the optimization and development of internal combustion engines capable of resisting knock. Although extensive databases and blending rules to estimate the octane numbers of mixtures have been developed and the effects of molecular structure on autoignition properties are somewhat understood, a comprehensive theoretical chemistry-based foundation for blending effects of fuels on engine operations is still to be developed. In this study, we present models that correlate the research octane number (RON) and motor octane number (MON) with simulated homogeneous gas-phase ignition delay times of stoichiometric fuel/air mixtures. These correlations attempt to bridge the gap between the fundamental autoignition behavior of the fuel (e.g., its chemistry and how reactivity changes with temperature and pressure) and engine properties such as its knocking behavior in a cooperative fuels research (CFR) engine. The study encompasses a total of 79 hydrocarbon gasoline surrogate mixtures including 11 primary reference fuels (PRF), 43 toluene primary reference fuels (TPRF), and 19 multicomponent (MC) surrogate mixtures. In addition to TPRF mixture components of iso-octane/n-heptane/toluene, MC mixtures, including n-heptane, iso-octane, toluene, 1-hexene, and 1,2,4-trimethylbenzene, were blended and tested to mimic real gasoline sensitivity. ASTM testing protocols D-2699 and D-2700 were used to measure the RON and MON of the MC mixtures in a CFR engine, while the PRF and TPRF mixtures’ octane ratings were obtained from the literature. The mixtures cover a RON range of 0–100, with the majority being in the 70–100 range. A parametric simulation study across a temperature range of 650–950 K and pressure range of 15–50 bar was carried out in a constant-volume homogeneous batch reactor to calculate chemical kinetic ignition delay times. Regression tools were utilized to find the conditions at which RON and MON

  20. Analysis of exergy loss of gasoline surrogate combustion process based on detailed chemical kinetics

    International Nuclear Information System (INIS)

    Sun, Hongjie; Yan, Feng; Yu, Hao; Su, W.H.

    2015-01-01

    Highlights: • We explored the exergy loss sources of gasoline engine like combustion process. • The model combined non-equilibrium thermodynamics with detailed chemical kinetics. • We explored effects of initial conditions on exergy loss of combustion process. • Exergy loss decreases 15% of fuel chemical exergy by design of initial conditions. • Correspondingly, the second law efficiency increases from 38.9% to 68.9%. - Abstract: Chemical reaction is the most important source of combustion irreversibility in premixed conditions, but details of the exergy loss mechanisms have not been explored yet. In this study numerical analysis based on non-equilibrium thermodynamics combined with detailed chemical kinetics is conducted to explore the exergy loss mechanism of gasoline engine like combustion process which is simplified as constant volume combustion. The fuel is represented by the common accepted gasoline surrogates which consist of four components: iso-octane (57%), n-heptane (16%), toluene (23%), and 2-pentene (4%). We find that overall exergy loss is mainly composed of three peaks along combustion generated from chemical reactions in three stages, the conversion from large fuel molecules into small molecules (as Stage 1), the H 2 O 2 loop-related reactions (as Stage 2), and the violent oxidation reactions of CO, H, and O (as Stage 3). The effects of individual combustion boundaries, including temperature, pressure, equivalence ratio, oxygen concentration, on combustion exergy loss have been widely investigated. The combined effects of combustion boundaries on the total loss of gasoline surrogates are also investigated. We find that in a gasoline engine with a compression ratio of 10, the total loss can be reduced from 31.3% to 24.3% using lean combustion. The total loss can be further reduced to 22.4% by introducing exhaust gas recirculation and boosting the inlet charge. If the compression ratio is increased to 17, the total loss can be decreased to

  1. Umbrellas can work under water: Using threatened species as indicator and management surrogates can improve coastal conservation

    Science.gov (United States)

    Gilby, Ben L.; Olds, Andrew D.; Connolly, Rod M.; Yabsley, Nicholas A.; Maxwell, Paul S.; Tibbetts, Ian R.; Schoeman, David S.; Schlacher, Thomas A.

    2017-12-01

    Species surrogates, the use of particular species to index habitat condition or to represent ecological assemblages are commonly identified in many ecosystems, but are less tested, and therefore less employed in estuaries. Estuaries provide important ecosystem goods (e.g. harvestable species) and services (e.g. carbon processing, coastal armouring), but require protection from multiple human activities, meaning that finding surrogates for estuarine condition or faunal assemblages is a significant knowledge gap. In this study, we test the efficacy of the threatened estuary ray Hemitrygon fluviorum, as a suitable indicator of ecosystem condition and management umbrella surrogate species for conservation prioritisation and monitoring purposes within estuaries. We surveyed fish assemblages and ray presence at ten sites within each of 22 estuaries in southeast Queensland, Australia, using one hour deployments of baited video arrays. We then tested for correlations between ray presence, a series of environmental variables considered important to ecosystem management within estuaries (i.e. testing rays as indicator species), and the co-occurring fish species (i.e. testing rays as umbrella species). Estuary rays function as both umbrella species and ecological indicators of habitat status in subtropical Australian estuaries. As umbrellas, ray occurrence concords with elevated species richness. As ecological indicators, ray distribution concords with habitats of good water quality (especially low turbidity) and more natural vegetation remaining in the catchment. These results highlight the potential for other threatened aquatic vertebrates that are both readily detectable and that are reliable proxies for ecosystems status to be become useful management tools in estuaries. The protection of such large, threatened species in coastal seascapes allows managers to address multiple targets for conservation, especially; (1) protecting species of conservation concern; (2

  2. Phenotypic and genomic comparison of Mycobacterium aurum and surrogate model species to Mycobacterium tuberculosis: implications for drug discovery.

    Science.gov (United States)

    Namouchi, Amine; Cimino, Mena; Favre-Rochex, Sandrine; Charles, Patricia; Gicquel, Brigitte

    2017-07-13

    Tuberculosis (TB) is caused by Mycobacterium tuberculosis and represents one of the major challenges facing drug discovery initiatives worldwide. The considerable rise in bacterial drug resistance in recent years has led to the need of new drugs and drug regimens. Model systems are regularly used to speed-up the drug discovery process and circumvent biosafety issues associated with manipulating M. tuberculosis. These include the use of strains such as Mycobacterium smegmatis and Mycobacterium marinum that can be handled in biosafety level 2 facilities, making high-throughput screening feasible. However, each of these model species have their own limitations. We report and describe the first complete genome sequence of Mycobacterium aurum ATCC23366, an environmental mycobacterium that can also grow in the gut of humans and animals as part of the microbiota. This species shows a comparable resistance profile to that of M. tuberculosis for several anti-TB drugs. The aims of this study were to (i) determine the drug resistance profile of a recently proposed model species, Mycobacterium aurum, strain ATCC23366, for anti-TB drug discovery as well as Mycobacterium smegmatis and Mycobacterium marinum (ii) sequence and annotate the complete genome sequence of this species obtained using Pacific Bioscience technology (iii) perform comparative genomics analyses of the various surrogate strains with M. tuberculosis (iv) discuss how the choice of the surrogate model used for drug screening can affect the drug discovery process. We describe the complete genome sequence of M. aurum, a surrogate model for anti-tuberculosis drug discovery. Most of the genes already reported to be associated with drug resistance are shared between all the surrogate strains and M. tuberculosis. We consider that M. aurum might be used in high-throughput screening for tuberculosis drug discovery. We also highly recommend the use of different model species during the drug discovery screening process.

  3. Dynamic role and importance of surrogate species for assessing potential adverse environmental impacts of genetically engineered insect-resistant plants on non-target organisms.

    Science.gov (United States)

    Wach, Michael; Hellmich, Richard L; Layton, Raymond; Romeis, Jörg; Gadaleta, Patricia G

    2016-08-01

    Surrogate species have a long history of use in research and regulatory settings to understand the potentially harmful effects of toxic substances including pesticides. More recently, surrogate species have been used to evaluate the potential effects of proteins contained in genetically engineered insect resistant (GEIR) crops. Species commonly used in GEIR crop testing include beneficial organisms such as honeybees, arthropod predators, and parasitoids. The choice of appropriate surrogates is influenced by scientific factors such as the knowledge of the mode of action and the spectrum of activity as well as societal factors such as protection goals that assign value to certain ecosystem services such as pollination or pest control. The primary reasons for using surrogates include the inability to test all possible organisms, the restrictions on using certain organisms in testing (e.g., rare, threatened, or endangered species), and the ability to achieve greater sensitivity and statistical power by using laboratory testing of certain species. The acceptance of surrogate species data can allow results from one region to be applied or "transported" for use in another region. On the basis of over a decade of using surrogate species to evaluate potential effects of GEIR crops, it appears that the current surrogates have worked well to predict effects of GEIR crops that have been developed (Carstens et al. GM Crops Food 5:1-5, 2014), and it is expected that they should work well to predict effects of future GEIR crops based on similar technologies.

  4. Methyl salicylate: a reactive chemical warfare agent surrogate to detect reaction with hypochlorite.

    Science.gov (United States)

    Salter, W Bruce; Owens, Jeffery R; Wander, Joseph D

    2011-11-01

    Methyl salicylate (MeS) has a rich history as an inert physical simulant for the chemical warfare agents sulfur mustard and soman, where it is used extensively for liquid- and vapor-permeation testing. Here we demonstrate possible utility of MeS as a reactivity simulant for chlorine-based decontaminants. In these experiments MeS was reacted with sodium hypochlorite varying stoichiometry, temperature, reaction time, and pH. No colored oxidation products were observed; however, chlorination of the aromatic ring occurred ortho (methyl 3-chlorosalicylate) and para (methyl 5-chlorosalicylate) to the position bearing the -OH group in both the mono- and disubstituted forms. The monosubstituted para product accumulated initially, and the ortho and 3,5-dichloro products formed over the next several hours. Yields from reactions conducted below pH 11 declined rapidly with decreasing pH. Reactions run at 40 °C produced predominantly para substitution, while those run at 0 °C produced lower yields of ortho- and para-substituted products. Reactions were also carried out on textile substrates of cotton, 50/50 nylon-cotton, and a meta aramid. The textile data broadly reproduced reaction times and stoichiometry observed in the liquid phase, but are complicated by physical and possibly chemical interactions with the fabric. These data indicate that, for hypochlorite-containing neutralizing agents operating at strongly alkaline pH, one can expect MeS to react stoichiometrically with the hypochlorite it encounters. This suggests utility of MeS in lieu of such highly hazardous surrogates as monochloroalkyl sulfides as a simulant for threat scenarios involving the stoichiometric decomposition of sulfur mustard. Specifically, the extent of coverage of the simulant on a fabric by the neutralizing agent can be directly measured. Similar reactivity toward other halogen oxidizing agents is likely but remains to be demonstrated.

  5. Mixed butanols addition to gasoline surrogates: Shock tube ignition delay time measurements and chemical kinetic modeling

    KAUST Repository

    AlRamadan, Abdullah S.

    2015-10-01

    The demand for fuels with high anti-knock quality has historically been rising, and will continue to increase with the development of downsized and turbocharged spark-ignition engines. Butanol isomers, such as 2-butanol and tert-butanol, have high octane ratings (RON of 105 and 107, respectively), and thus mixed butanols (68.8% by volume of 2-butanol and 31.2% by volume of tert-butanol) can be added to the conventional petroleum-derived gasoline fuels to improve octane performance. In the present work, the effect of mixed butanols addition to gasoline surrogates has been investigated in a high-pressure shock tube facility. The ignition delay times of mixed butanols stoichiometric mixtures were measured at 20 and 40bar over a temperature range of 800-1200K. Next, 10vol% and 20vol% of mixed butanols (MB) were blended with two different toluene/n-heptane/iso-octane (TPRF) fuel blends having octane ratings of RON 90/MON 81.7 and RON 84.6/MON 79.3. These MB/TPRF mixtures were investigated in the shock tube conditions similar to those mentioned above. A chemical kinetic model was developed to simulate the low- and high-temperature oxidation of mixed butanols and MB/TPRF blends. The proposed model is in good agreement with the experimental data with some deviations at low temperatures. The effect of mixed butanols addition to TPRFs is marginal when examining the ignition delay times at high temperatures. However, when extended to lower temperatures (T < 850K), the model shows that the mixed butanols addition to TPRFs causes the ignition delay times to increase and hence behaves like an octane booster at engine-like conditions. © 2015 The Combustion Institute.

  6. Mixed butanols addition to gasoline surrogates: Shock tube ignition delay time measurements and chemical kinetic modeling

    KAUST Repository

    AlRamadan, Abdullah S.; Badra, Jihad; Javed, Tamour; Alabbad, Mohammed; Bokhumseen, Nehal; Gaillard, Patrick; Babiker, Hassan; Farooq, Aamir; Sarathy, Mani

    2015-01-01

    work, the effect of mixed butanols addition to gasoline surrogates has been investigated in a high-pressure shock tube facility. The ignition delay times of mixed butanols stoichiometric mixtures were measured at 20 and 40bar over a temperature range

  7. Molecular activation analysis for chemical species studies

    International Nuclear Information System (INIS)

    Chai Zhifang; Mao Xueying; Wang Yuqi; Sun Jingxin; Qian Qingfang; Hou Xiaolin; Zhang Peiqun; Chen Chunying; Feng Weiyu; Ding Wenjun; Li Xiaolin; Li Chunsheng; Dai Xiongxin

    2001-01-01

    The Molecular Activation Analysis (MAA) mainly refers to an activation analysis method that is able to provide information about the chemical species of elements in systems of interest, though its exact definition has remained to be assigned. Its development is strongly stimulated by the urgent need to know the chemical species of elements, because the bulk contents or concentrations are often insignificant for judging biological, environmental or geochemical effects of elements. In this paper, the features, methodology and limitation of MAA were outlined. Further, the up-to-date MAA progress made in our laboratory was introduced as well. (author)

  8. Use of abundance of one species as a surrogate for abundance of others

    Science.gov (United States)

    Samuel A. Cushman; Kevin S. McKelvey; Barry R. Noon; Kevin McGarigal

    2010-01-01

    Indicator species concepts have a long history in conservation biology. Arguments in favor of these approaches generally stress expediency and assume efficacy. We tested the premise that the abundance patterns of one species can be used to infer those of other species. Our data consisted of 72,495 bird observations on 55 species across 1046 plots distributed across 30...

  9. Birds as biodiversity surrogates

    DEFF Research Database (Denmark)

    Larsen, Frank Wugt; Bladt, Jesper Stentoft; Balmford, Andrew

    2012-01-01

    1. Most biodiversity is still unknown, and therefore, priority areas for conservation typically are identified based on the presence of surrogates, or indicator groups. Birds are commonly used as surrogates of biodiversity owing to the wide availability of relevant data and their broad popular...... and applications.?Good surrogates of biodiversity are necessary to help identify conservation areas that will be effective in preventing species extinctions. Birds perform fairly well as surrogates in cases where birds are relatively speciose, but overall effectiveness will be improved by adding additional data...... from other taxa, in particular from range-restricted species. Conservation solutions with focus on birds as biodiversity surrogate could therefore benefit from also incorporating species data from other taxa....

  10. EARLY LIFE STAGE TOXICITY OF COPPER TO ENDANGERED AND SURROGATE FISH SPECIES

    Science.gov (United States)

    Water quality criteria (WQC) for the protection of aquatic life have not explicitly considered the degree of protection afforded to aquatic species listed as endangered or threatened under the U.S. Endangered Species Act (listed species) . Most WQCs are based primarily on respon...

  11. Aquatic plants: Test species sensitivity and minimum data requirement evaluations for chemical risk assessments and aquatic life criteria development for the USA

    Science.gov (United States)

    Phytotoxicity results from the publicly-available ECOTOX database were summarized for 20 chemicals and 188 aquatic plants to determine species sensitivities and the ability of a species-limited toxicity data set to serve as a surrogate for a larger data set. The lowest effect con...

  12. Sublethal Effects in Pest Management: A Surrogate Species Perspective on Fruit Fly Control

    Directory of Open Access Journals (Sweden)

    John E. Banks

    2017-07-01

    Full Text Available Tephritid fruit flies are economically important orchard pests globally. While much effort has focused on controlling individual species with a combination of pesticides and biological control, less attention has been paid to managing assemblages of species. Although several tephritid species may co-occur in orchards/cultivated areas, especially in mixed-cropping schemes, their responses to pesticides may be highly variable. Furthermore, predictive efforts about toxicant effects are generally based on acute toxicity, with little or no regard to long-term population effects. Using a simple matrix model parameterized with life history data, we quantified the responses of several tephritid species to the sublethal effects of a toxicant acting on fecundity. Using a critical threshold to determine levels of fecundity reduction below which species are driven to local extinction, we determined that threshold levels vary widely for the three tephritid species. In particular, Bactrocera dorsalis was the most robust of the three species, followed by Ceratitis capitata, and then B. cucurbitae, suggesting individual species responses should be taken into account when planning for area-wide pest control. The rank-order of susceptibility contrasts with results from several field/lab studies testing the same species, suggesting that considering a combination of life history traits and individual species susceptibility is necessary for understanding population responses of species assemblages to toxicant exposure.

  13. Analysis of chemical constituents in Cistanche species.

    Science.gov (United States)

    Jiang, Yong; Tu, Peng-Fei

    2009-03-13

    Species of the genus of Cistanche (Rou Cong Rong in Chinese) are perennial parasite herbs, and are mainly distributed in arid lands and warm deserts. As a superior tonic for the treatment of kidney deficiency, impotence, female infertility, morbid leucorrhea, profuse metrorrhagia and senile constipation, Cistanche herbs earned the honor of "Ginseng of the desert". Recently, there has been increasing scientific attention on Herba Cistanche for its remarkable bioactivities including antioxidation, neuroprotection, and anti-aging. The chemical constituents of Cistanche plants mainly include volatile oils and non-volatile phenylethanoid glycosides (PhGs), iridoids, lignans, alditols, oligosaccharides and polysaccharides. Pharmacological studies show that PhGs are the main active components for curing kidney deficiency, antioxidation and neuroprotection; galactitol and oligosaccharides are the representatives for the treatment of senile constipation, while polysaccharides are responsible for improving body immunity. In this paper, the advances on the chemical constituents of Cistanche plants and their corresponding analyses are reviewed.

  14. Fluxes of chemically reactive species inferred from mean concentration measurements

    NARCIS (Netherlands)

    Galmarini, S.; Vilà-Guerau De Arellano, J.; Duyzer, J.H.

    1997-01-01

    A method is presented for the calculation of the fluxes of chemically reactive species on the basis of routine measurements of meteorological variables and chemical species. The method takes explicity into account the influence of chemical reactions on the fluxes of the species. As a demonstration

  15. [Ants’ higher taxa as surrogates of species richness in a chronosequence of fallows, old-grown forests and agroforestry systems in the Eastern Amazon, Brazil].

    Science.gov (United States)

    Muñoz Gutiérrez, Jhonatan Andrés; Roussea, Guillaume Xavier; Andrade-Silva, Joudellys; Delabie, Jacques Hubert Charles

    2017-03-01

    Deforestation in Amazon forests is one of the main causes for biodiversity loss worldwide. Ants are key into the ecosystem because act like engineers; hence, the loss of ants’ biodiversity may be a guide to measure the loss of essential functions into the ecosystems. The aim of this study was to evaluate soil ant’s richness and to estimate whether higher taxa levels (Subfamily and Genus) can be used as surrogates of species richness in different vegetation types (fallows, old-growth forests and agroforestry systems) in Eastern Amazon. The samples were taken in 65 areas in the Maranhão and Pará States in the period 2011-2014. The sampling scheme followed the procedure of Tropical Soil Biology and Fertility (TSBF). Initially, the vegetation types were characterized according to their age and estimated species richness. Linear and exponential functions were applied to evaluate if higher taxa can be used as surrogates and correlated with the Pearson coefficient. In total, 180 species distributed in 60 genera were identified. The results showed that ant species richness was higher in intermediate fallows (88) and old secondary forest (76), and was lower in agroforestry systems (38) and mature riparian forest (35). The genus level was the best surrogate to estimate the ant’s species richness across the different vegetation types, and explained 72-97 % (P agroforestry systems may contribute in the conservation of Eastern Amazon ant community.

  16. Effects of herbicides on Behr's metalmark butterfly, a surrogate species for the endangered butterfly, Lange's metalmark

    International Nuclear Information System (INIS)

    Stark, John D.; Chen Xuedong; Johnson, Catherine S.

    2012-01-01

    Lange's metalmark butterfly, Apodemia mormo langei Comstock, is in danger of extinction due to loss of habitat caused by invasive exotic plants which are eliminating its food, naked stem buckwheat. Herbicides are being used to remove invasive weeds from the dunes; however, little is known about the potential effects of herbicides on butterflies. To address this concern we evaluated potential toxic effects of three herbicides on Behr's metalmark, a close relative of Lange's metalmark. First instars were exposed to recommended field rates of triclopyr, sethoxydim, and imazapyr. Life history parameters were recorded after exposure. These herbicides reduced the number of adults that emerged from pupation (24–36%). Each herbicide has a different mode of action. Therefore, we speculate that effects are due to inert ingredients or indirect effects on food plant quality. If these herbicides act the same in A. mormo langei, they may contribute to the decline of this species. - Highlights: ► We evaluated the effects of three herbicides on the butterfly, Behr's metalmark. ► These herbicides are used to control invasive weeds in butterfly habitat. ► The herbicides reduced adult butterfly emergence. - Herbicides are used to remove invasive weeds from butterfly habitat. Certain herbicides may be having a negative effect on butterflies.

  17. CHEMICAL COMPOSITION OF CAATINGA POTENTIAL FORAGES SPECIES

    Directory of Open Access Journals (Sweden)

    Dynara Layza de Souza da Silva

    2015-12-01

    Full Text Available Chemical composition of some potential forages species, natives from Caatinga region, were evaluated. Samples of Macroptilium heterophyllum, Stylosanthes humilis, Rhynchosia mínima, Desmodium tortuosum Sw. Dc, Merremia aegyptia, Mimosa tenuiflora Wild, Bauhinia cheilantha and as well Macroptilium lathyroides, Caesalpinia pyramidalis and Mimosa tenuiflora hays were collected in Rio Grande do Norte Stated, during 2011 rainy season. The analyses: dry matter (DM, crude protein (CP mineral matter (MM ether extract  (EE neutral detergent fiber (NDF, acid detergent fiber (ADF, lignin (LIG, insoluble neutral detergent nitrogen, (INDN insoluble acid detergent nitrogen, (ADIN, total phenol (TF and total tannin (TT were done at Embrapa Caprinos e Ovinos in Ceará State. Plants analyzed, as expected, for tropical species, exhibited high level of cell wall constituents, high lignifications rate and revealed substantial presence of anti nutritional compounds. However, regardless of this data, the main problem, for grazing animals, is due to its xerophytes characteristics. Most of the shrubs and trees are deciduous, losing its leaves during the dry season. In addition, herbaceous presents a very rapid lifetime cycle, germinating and senescing during the brief wet season.

  18. Chemical aging of single and multicomponent biomass burning aerosol surrogate particles by OH: implications for cloud condensation nucleus activity

    Directory of Open Access Journals (Sweden)

    J. H. Slade

    2015-09-01

    Full Text Available Multiphase OH and O3 oxidation reactions with atmospheric organic aerosol (OA can influence particle physicochemical properties including composition, morphology, and lifetime. Chemical aging of initially insoluble or low-soluble single-component OA by OH and O3 can increase their water solubility and hygroscopicity, making them more active as cloud condensation nuclei (CCN and susceptible to wet deposition. However, an outstanding problem is whether the effects of chemical aging on their CCN activity are preserved when mixed with other organic or inorganic compounds exhibiting greater water solubility. In this work, the CCN activity of laboratory-generated biomass burning aerosol (BBA surrogate particles exposed to OH and O3 is evaluated by determining the hygroscopicity parameter, κ, as a function of particle type, mixing state, and OH and O3 exposure applying a CCN counter (CCNc coupled to an aerosol flow reactor (AFR. Levoglucosan (LEV, 4-methyl-5-nitrocatechol (MNC, and potassium sulfate (KS serve as representative BBA compounds that exhibit different hygroscopicity, water solubility, chemical functionalities, and reactivity with OH radicals, and thus exemplify the complexity of mixed inorganic/organic aerosol in the atmosphere. The CCN activities of all of the particles were unaffected by O3 exposure. Following exposure to OH, κ of MNC was enhanced by an order of magnitude, from 0.009 to ~ 0.1, indicating that chemically aged MNC particles are better CCN and more prone to wet deposition than pure MNC particles. No significant enhancement in κ was observed for pure LEV particles following OH exposure. κ of the internally mixed particles was not affected by OH oxidation. Furthermore, the CCN activity of OH-exposed MNC-coated KS particles is similar to the OH unexposed atomized 1 : 1 by mass MNC : KS binary-component particles. Our results strongly suggest that when OA is dominated by water-soluble organic carbon (WSOC or inorganic ions

  19. Comparative toxicity of ten organic chemicals to four earthworm species

    Energy Technology Data Exchange (ETDEWEB)

    Neuhauser, E.F.; Durkin, P.R.; Malecki, M.R.; Anatra, M.

    1986-01-01

    Ten organic chemicals were tested for toxicity to four earthworm species: Allolobophora tuberculata, Eisenia fetida, Eudrilus eugeniae and Perionyx excavatus, using the European Economic Community's (EEC) earthworm artificial soil and contact testing procedure. The phenols were the most toxic chemicals tested, followed by the amine, substituted benzenes, halogenated aliphatic hydrocarbon, polycyclic aromatic hydrocarbon and phthalate as the least toxic chemical tested. Correlations among species within each type of test for a given chemical were extremely high, suggesting that the selection of earthworm test species does not markedly affect the assessment of a chemical's toxicity. The correlation between the two tests was low for all test species. The contact test LC50 for a given chemical cannot be directly correlated to an artificial soil test LC50 for the same earthworm species.

  20. A minimalist functional group (MFG) approach for surrogate fuel formulation

    KAUST Repository

    Abdul Jameel, Abdul Gani; Naser, Nimal; Issayev, Gani; Touitou, Jamal; Ghosh, Manik Kumer; Emwas, Abdul-Hamid M.; Farooq, Aamir; Dooley, Stephen; Sarathy, Mani

    2018-01-01

    Surrogate fuel formulation has drawn significant interest due to its relevance towards understanding combustion properties of complex fuel mixtures. In this work, we present a novel approach for surrogate fuel formulation by matching target fuel functional groups, while minimizing the number of surrogate species. Five key functional groups; paraffinic CH, paraffinic CH, paraffinic CH, naphthenic CH–CH and aromatic C–CH groups in addition to structural information provided by the Branching Index (BI) were chosen as matching targets. Surrogates were developed for six FACE (Fuels for Advanced Combustion Engines) gasoline target fuels, namely FACE A, C, F, G, I and J. The five functional groups present in the fuels were qualitatively and quantitatively identified using high resolution H Nuclear Magnetic Resonance (NMR) spectroscopy. A further constraint was imposed in limiting the number of surrogate components to a maximum of two. This simplifies the process of surrogate formulation, facilitates surrogate testing, and significantly reduces the size and time involved in developing chemical kinetic models by reducing the number of thermochemical and kinetic parameters requiring estimation. Fewer species also reduces the computational expenses involved in simulating combustion in practical devices. The proposed surrogate formulation methodology is denoted as the Minimalist Functional Group (MFG) approach. The MFG surrogates were experimentally tested against their target fuels using Ignition Delay Times (IDT) measured in an Ignition Quality Tester (IQT), as specified by the standard ASTM D6890 methodology, and in a Rapid Compression Machine (RCM). Threshold Sooting Index (TSI) and Smoke Point (SP) measurements were also performed to determine the sooting propensities of the surrogates and target fuels. The results showed that MFG surrogates were able to reproduce the aforementioned combustion properties of the target FACE gasolines across a wide range of conditions

  1. A minimalist functional group (MFG) approach for surrogate fuel formulation

    KAUST Repository

    Abdul Jameel, Abdul Gani

    2018-03-20

    Surrogate fuel formulation has drawn significant interest due to its relevance towards understanding combustion properties of complex fuel mixtures. In this work, we present a novel approach for surrogate fuel formulation by matching target fuel functional groups, while minimizing the number of surrogate species. Five key functional groups; paraffinic CH, paraffinic CH, paraffinic CH, naphthenic CH–CH and aromatic C–CH groups in addition to structural information provided by the Branching Index (BI) were chosen as matching targets. Surrogates were developed for six FACE (Fuels for Advanced Combustion Engines) gasoline target fuels, namely FACE A, C, F, G, I and J. The five functional groups present in the fuels were qualitatively and quantitatively identified using high resolution H Nuclear Magnetic Resonance (NMR) spectroscopy. A further constraint was imposed in limiting the number of surrogate components to a maximum of two. This simplifies the process of surrogate formulation, facilitates surrogate testing, and significantly reduces the size and time involved in developing chemical kinetic models by reducing the number of thermochemical and kinetic parameters requiring estimation. Fewer species also reduces the computational expenses involved in simulating combustion in practical devices. The proposed surrogate formulation methodology is denoted as the Minimalist Functional Group (MFG) approach. The MFG surrogates were experimentally tested against their target fuels using Ignition Delay Times (IDT) measured in an Ignition Quality Tester (IQT), as specified by the standard ASTM D6890 methodology, and in a Rapid Compression Machine (RCM). Threshold Sooting Index (TSI) and Smoke Point (SP) measurements were also performed to determine the sooting propensities of the surrogates and target fuels. The results showed that MFG surrogates were able to reproduce the aforementioned combustion properties of the target FACE gasolines across a wide range of conditions

  2. Surrogate motherhood

    OpenAIRE

    Arteta-Acosta Cindy

    2011-01-01

    Surrogate motherhood, also known as surrogacy, has recently become achance to exercise the right of paternity by some people. Surrogacy itself did notinvolve a disadvantaged idea, but when this is coupled with scientific experimentsand economic and personal interests, requires intervention of the State tolegislate about consequences arising from the unlimited execution of this practice. Since 70’s,developed countries have been creating laws, decrees and regulations to regulateassisted reprodu...

  3. Transuranic chemical species in groundwater. Final report

    International Nuclear Information System (INIS)

    Cowan, C.E.; Jenne, E.A.; Robertson, D.E.; Nelson, D.M.; Abel, K.H.

    1985-02-01

    For the past several years, staff at Pacific Northwest Laboratory (PNL) have been studying the mobility of actinides, primarily plutonium, in the groundwater of a low-level disposal site. This research has provided valuable insights into the behavior of plutonium in the groundwater. Based on the analytical data and geochemical modeling, it appears that the plutonium that enters the trench, primarily in the higher oxidation states, Pu(V,VI), is rapidly reduced as the water migrates through the highly reducing sediments of the trench and is removed from the water by adsorption of the reduced plutonium, Pu(III,IV), onto the sediments. The Pu(V,VI) also appears to be reduced in the groundwater, although not as rapidly as in the trench sediments, and removed by adsorption. Because of the redox reduction that occurs during the migration of the groundwater, the system is not at redox equilibrium. Based on the discrepancies between the calculated and analytically determined redox distribution and charge-form speciation, the thermodynamic data bases for plutonium appear either to be missing or to contain incorrect thermodynamic data for several aqueous plutonium species, including the carbonate and organic complexes of plutonium. Further research is required to determine the kinetics of plutonium oxidation/reduction reactions in natural groundwater systems and to determine thermodynamic data for carbonate and organic complexes of plutonium. 52 references, 1 figure, 6 tables

  4. Chemical cues mediate species recognition in field crickets

    Directory of Open Access Journals (Sweden)

    Frances eTyler

    2015-05-01

    Full Text Available Cuticular hydrocarbons (CHCs are important in mate choice in many insects, and may be used for species recognition if CHC profiles differ between potentially hybridizing species. In the sibling field cricket species Gryllus campestris and G. bimaculatus, females of G. bimaculatus are tolerant towards G. campestris males and can mate with them. However, G. campestris females are highly aggressive towards heterospecific G. bimaculatus males, and matings between them never happen. We examined whether cricket females might use CHCs to determine the species identity of their potential mates. We firstly analyzed the cuticular chemical profile by gas chromatography and mass spectrometry to assess the potential of CHCs to be used for species recognition in these crickets. We then manipulated females’ ability to detect chemical cues by carrying out chemical ablation of the antennae, and measured changes in aggressive responses to heterospecific males. We show that there are significant interspecies differences in CHC expression for both sexes, and that females with chemically ablated antennae reduce aggressive behavior towards heterospecific males. Our findings support the prediction that cuticular semiochemicals can play a key role in reproductive isolation between closely related insect species.

  5. Barrier properties to surrogates of hydrogenated carbon nano-films deposited on PET by plasma-enhanced chemical vapour deposition.

    Science.gov (United States)

    Oliveira, Éder C; Echegoyen, Yolanda; Nerin, Cristina; Cruz, Sandra A

    2014-01-01

    Poly(ethylene terephthalate) resin was contaminated with a series of surrogates using a US Food and Drug Administration protocol. The contaminated samples were coated with two different kinds of hydrogenated amorphous carbon thin films (a-C:H): one with diamond-like hydrogenated amorphous carbon and another with polymer-like hydrogenated carbon (PLCH) phases. To evaluate the barrier properties of the a-C:H films, migration assays were performed using food simulants. After the tests, analysis by gas chromatography with different detectors was carried out. The appearance of the films before and after the migration experiments was studied by field emission scanning electron microscopy. The results showed that a-C:H films have good barrier properties for most of the evaluated compounds, mainly when they are deposited as PLCH phase.

  6. Chemical Characteristics of Six Woody Species for Alley Cropping

    Directory of Open Access Journals (Sweden)

    Mosango, M.

    1999-01-01

    Full Text Available Leaves of six woody species (Leguminosae for alley cropping have been chemically analysed in order to evaluate their potentiality in the restoration of soil fertility. These species are : Acacia mangium, Cajanus cajan, Flemingia grahamiana, F. macrophylla, Leucaena leucocephala and Sesbania sesban. Nitrogen, carbon, cellulose, hemicellulose, lignin, active fraction and ash contents were determined as well as C/N and L/N ratios. AH these species appear to be rich in N and C. Fiber contents (cellulose, hemicellulose and lignin are globally low but variable from one species to another. C/N and L/N ratios are globally low. Among these species, Leucaena leucocephala and Senna spectabilis show the lowest C/N and LIN ratios. Such low values of C/N and L/N are normally found in species with rapid decomposition of organic matter.

  7. Quantification of the removal of chemical species by snow

    Energy Technology Data Exchange (ETDEWEB)

    Schwikowski, M.; Baltensperger, U.; Bruetsch, S.; Keil, R.; Gaeggeler, H.W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Poulida, O. [Frederick Research Center, Nicosia (Cyprus)

    1997-09-01

    In order to quantify the scavenging of chemical species in mixed phase clouds, in-cloud field experiments were conducted in October and November 1993 at the high-alpine research station Jungfraujoch. On the average, air to snow transfer fractions were rather low with the highest value of 0.5 for nitrate, thus, most of the air borne chemical mass remained in the air parcel after precipitation. (author) 1 fig., 4 refs.

  8. Combustion Kinetic Studies of Gasolines and Surrogates

    KAUST Repository

    Javed, Tamour

    2016-11-01

    Future thrusts for gasoline engine development can be broadly summarized into two categories: (i) efficiency improvements in conventional spark ignition engines, and (ii) development of advance compression ignition (ACI) concepts. Efficiency improvements in conventional spark ignition engines requires downsizing (and turbocharging) which may be achieved by using high octane gasolines, whereas, low octane gasolines fuels are anticipated for ACI concepts. The current work provides the essential combustion kinetic data, targeting both thrusts, that is needed to develop high fidelity gasoline surrogate mechanisms and surrogate complexity guidelines. Ignition delay times of a wide range of certified gasolines and surrogates are reported here. These measurements were performed in shock tubes and rapid compression machines over a wide range of experimental conditions (650 – 1250 K, 10 – 40 bar) relevant to internal combustion engines. Using the measured the data and chemical kinetic analyses, the surrogate complexity requirements for these gasolines in homogeneous environments are specified. For the discussions presented here, gasolines are classified into three categories: (i)\\tLow octane gasolines including Saudi Aramco’s light naphtha fuel (anti-knock index, AKI = (RON + MON)/2 = 64; Sensitivity (S) = RON – MON = 1), certified FACE (Fuels for Advanced Combustion Engines) gasoline I and J (AKI ~ 70, S = 0.7 and 3 respectively), and their Primary Reference Fuels (PRF, mixtures of n-heptane and iso-octane) and multi-component surrogates. (ii)\\t Mid octane gasolines including FACE A and C (AKI ~ 84, S ~ 0 and 1 respectively) and their PRF surrogates. Laser absorption measurements of intermediate and product species formed during gasoline/surrogate oxidation are also reported. (iii)\\t A wide range of n-heptane/iso-octane/toluene (TPRF) blends to adequately represent the octane and sensitivity requirements of high octane gasolines including FACE gasoline F and G

  9. Reproductive Impacts of Endocrine-Disrupting Chemicals on Wildlife Species: Implications for Conservation of Endangered Species.

    Science.gov (United States)

    Tubbs, Christopher W; McDonough, Caitlin E

    2018-02-15

    Wildlife have proven valuable to our understanding of the potential effects of endocrine-disrupting chemicals (EDCs) on human health by contributing considerably to our understanding of the mechanisms and consequences of EDC exposure. But the threats EDCs present to populations of wildlife species themselves are significant, particularly for endangered species whose existence is vulnerable to any reproductive perturbation. However, few studies address the threats EDCs pose to endangered species owing to challenges associated with their study. Here, we highlight those barriers and review the available literature concerning EDC effects on endangered species. Drawing from other investigations into nonthreatened wildlife species, we highlight opportunities for new approaches to advance our understanding and potentially mitigate the effects of EDCs on endangered species to enhance their fertility.

  10. Protectiveness of Species Sensitivity Distribution Hazard Concentrations for Acute Toxicity Used in Endangered Species Risk Assessment

    Science.gov (United States)

    A primary objective of threatened and endangered species conservation is to ensure that chemical contaminants and other stressors do not adversely affect listed species. Assessments of the ecological risks of chemical exposures to listed species often rely on the use of surrogate...

  11. Chemical thermodynamics of iodine species in the HTGR fuel particle

    International Nuclear Information System (INIS)

    Lindemer, T.B.

    1982-09-01

    The iodine-containing species in an intact fuel particle in the high-temperature gas-cooled reactor (HTGR) have been calculated. Assumptions include: (1) attainment of chemical thermodynamic equilibrium among all species in the open porosity of the particle, primarily in the buffer layer; and (2) fission-product concentrations in proportion to their yields. The primary gaseous species is calculated to be cesium iodide; in carbide-containing fuels, gaseous barium iodide may exhibit equivalent pressures. The condensed iodine-containing phase is usually cesium iodide, but in carbide-containing fuels, barium iodide may be stable instead. Absorption of elemental iodine on the carbon in the particle appears to be less than or equal to 10 -4 μg I/g C. The fission-product-spectra excess of cesium over iodine would generally be adsorbed on the carbon, but may form Cs 2 MoO 4 under some circumstances

  12. Chemical species of plutonium in Hanford radioactive tank waste

    International Nuclear Information System (INIS)

    Barney, G.S.

    1997-01-01

    Large quantities of radioactive wastes have been generated at the Hanford Site over its operating life. The wastes with the highest activities are stored underground in 177 large (mostly one million gallon volume) concrete tanks with steel liners. The wastes contain processing chemicals, cladding chemicals, fission products, and actinides that were neutralized to a basic pH before addition to the tanks to prevent corrosion of the steel liners. Because the mission of the Hanford Site was to provide plutonium for defense purposes, the amount of plutonium lost to the wastes was relatively small. The best estimate of the amount of plutonium lost to all the waste tanks is about 500 kg. Given uncertainties in the measurements, some estimates are as high as 1,000 kg (Roetman et al. 1994). The wastes generally consist of (1) a sludge layer generated by precipitation of dissolved metals from aqueous wastes solutions during neutralization with sodium hydroxide, (2) a salt cake layer formed by crystallization of salts after evaporation of the supernate solution, and (3) an aqueous supernate solution that exists as a separate layer or as liquid contained in cavities between sludge or salt cake particles. The identity of chemical species of plutonium in these wastes will allow a better understanding of the behavior of the plutonium during storage in tanks, retrieval of the wastes, and processing of the wastes. Plutonium chemistry in the wastes is important to criticality and environmental concerns, and in processing the wastes for final disposal. Plutonium has been found to exist mainly in the sludge layers of the tanks along with other precipitated metal hydrous oxides. This is expected due to its low solubility in basic aqueous solutions. Tank supernate solutions do not contain high concentrations of plutonium even though some tanks contain high concentrations of complexing agents. The solutions also contain significant concentrations of hydroxide which competes with other

  13. Improving chemical species tomography of turbulent flows using covariance estimation.

    Science.gov (United States)

    Grauer, Samuel J; Hadwin, Paul J; Daun, Kyle J

    2017-05-01

    Chemical species tomography (CST) experiments can be divided into limited-data and full-rank cases. Both require solving ill-posed inverse problems, and thus the measurement data must be supplemented with prior information to carry out reconstructions. The Bayesian framework formalizes the role of additive information, expressed as the mean and covariance of a joint-normal prior probability density function. We present techniques for estimating the spatial covariance of a flow under limited-data and full-rank conditions. Our results show that incorporating a covariance estimate into CST reconstruction via a Bayesian prior increases the accuracy of instantaneous estimates. Improvements are especially dramatic in real-time limited-data CST, which is directly applicable to many industrially relevant experiments.

  14. MICROMORPHOLOGICAL AND CHEMICAL ASPECTS OF SOME LICHENIZED FUNGI SPECIES

    Directory of Open Access Journals (Sweden)

    PÎNDARU DIANA-MIHAELA

    2012-12-01

    Full Text Available At present, lichenized fungi are used in biomonitoring studies of air quality, being good receptors in the climate change. This paper aims to investigate surface micromorphology of Xanthoria parietina and Phaeophyscia orbicularis species (Lecanoromycetes, Ascomycota. The study also includes the investigation of selected chemical parameters as pH and conductivity of the lichenized fungi samples collected from various locations in the Iaşi County (Romania. Measurements of the pH provide information on the degree of pollution in the location of interest. Bark trees pH was also investigated in order to see if our matrix substrate influences the pH of the interest lichenized fungi samples.

  15. Chemical composition of some wild peanut species (Arachis L.) seeds.

    Science.gov (United States)

    Grosso, N R; Nepote, V; Guzmán, C A

    2000-03-01

    Oil, protein, ash, and carbohydrate contents, iodine value, and fatty acid and sterol compositions were studied in seeds of Arachis trinitensis, A. chiquitana, A. kempff-mercadoi, A. diogoi, A. benensis, A. appressipila, A. valida, A. kretschmeri, A. helodes, A. kuhlmannii, A. williamsii, A. sylvestris, A. matiensis, A. pintoi, A. hoehnei, A. villosa, and A. stenosperma. Oil content was greatest in A.stenosperma (mean value = 51.8%). The protein level was higher in A. sylvestris (30.1%) and A. villosa (29.5%). Mean value of oleic acid varied between 30.6% (A. matiensis) and 46.8% (Arachis villosa), and linoleic acid oscillated between 34.1% (A. villosa) and 47.4% (A. appressipila). The better oleic-to-linoleic (O/L) ratio was exhibited by A. villosa (1.38). Some species showed higher concentration of behenic acid. The greatest level of this fatty acid was found in A. matiensis (6.2%). Iodine value was lower in A. valida (99.2). The sterol composition in the different peanut species showed higher concentration of beta-sitosterol (mean values oscillated between 55.7 and 60.2%) followed by campesterol (12.4-16. 5%), stigmasterol (9.7-13.3%), and Delta(5)-avenasterol (9.7-13.4%). The chemical quality and stability of oils (iodine value and O/L ratio) from wild peanut studied in this work are not better than those of cultivated peanut.

  16. Thermodynamic properties of chemical species of waste radionuclides

    International Nuclear Information System (INIS)

    Silva, R.J.; Nitsche, H.

    1984-01-01

    The object of the experimental program at Lawrence Berkeley Laboratory is to identify gaps or conflicts in thermodynamic data on the solubilities of compounds and on the formation of solution complexes of waste radionuclides needed for the reliable prediction of solution concentrations. It involves laboratory measurements necessary to (1) generate specific new data, where none exists, in order to demonstrate the importance of a particular solution species, compound or solution parameter (e.g., temperature, Eh) and to (2) resolve conflicts in existing thermodynamic data on important species or compounds. The measurement of the solubility of AmOHCO 3 in 0.1 M NaClO 4 at 25 0 C and 1 atmosphere pressure has been completed. From the experimental data, an average solubility product quotient, Qsp, was evaluated for the reaction, AmOHCO 3 (S) + 2H + = Am 3+ + HCO 3 - + H 2 O. The logarithm of Qsp was calculated to be 2.74 +/- .17. Speciation calculations, using this new data plus reported data on the solubility of Am(OH) 3 and the hydrolysis and carbonate complexation of Am 3+ , indicate that the presence of carbonate can have a substantial effect on the nature of compounds and solution species formed by americium in ground waters. Since actinides in a given oxidation state tend to exhibit similar chemical properties, this result should apply to other actinides in the trivalent state. Thus, the effect of carbonate on the solubilities and complexation of trivalent actinides should be included in any predictive modelling studies required for licensing. 27 references, 4 figures, 5 tables

  17. Experimental determination of the speciation, partitioning, and release of perrhenate as a chemical surrogate for pertechnetate from a sodalite-bearing multiphase ceramic waste form

    Energy Technology Data Exchange (ETDEWEB)

    Pierce, Eric M.; Lukens, Wayne W.; Fitts, Jeff. P.; Jantzen, Carol. M.; Tang, G.

    2013-12-01

    A key component to closing the nuclear fuel cycle is the storage and disposition of nuclear waste in geologic systems. Multiphase ceramic waste forms have been studied extensively as a potential host matrix for nuclear waste. Understanding the speciation, partitioning, and release behavior of radionuclides immobilized in multiphase ceramic waste forms is a critical aspect of developing the scientific and technical basis for nuclear waste management. In this study, we evaluated a sodalite-bearing multiphase ceramic waste form (i.e., fluidized-bed steam reform sodium aluminosilicate [FBSR NAS] product) as a potential host matrix for long-lived radionuclides, such as technetium (99Tc). The FBSR NAS material consists primarily of nepheline (ideally NaAlSiO4), anion-bearing sodalites (ideally M8[Al6Si6O24]X2, where M refers to alkali and alkaline earth cations and X refers to monovalent anions), and nosean (ideally Na8[AlSiO4]6SO4). Bulk X-ray absorption fine structure analysis of the multiphase ceramic waste form, suggest rhenium (Re) is in the Re(VII) oxidation state and has partitioned to a Re-bearing sodalite phase (most likely a perrhenate sodalite Na8[Al6Si6O24](ReO4)2). Rhenium was added as a chemical surrogate for 99Tc during the FBSR NAS synthesis process. The weathering behavior of the FBSR NAS material was evaluated under hydraulically unsaturated conditions with deionized water at 90 ?C. The steady-state Al, Na, and Si concentrations suggests the weathering mechanisms are consistent with what has been observed for other aluminosilicate minerals and include a combination of ion exchange, network hydrolysis, and the formation of an enriched-silica surface layer or phase. The steady-state S and Re concentrations are within an order of magnitude of the nosean and perrhenate sodalite solubility, respectively. The order of magnitude difference between the observed and predicted concentration for Re and S may be associated with the fact that the anion

  18. Comparing bee species responses to chemical mixtures: Common response patterns?

    Directory of Open Access Journals (Sweden)

    Alex Robinson

    Full Text Available Pollinators in agricultural landscapes can be exposed to mixtures of pesticides and environmental pollutants. Existing mixture toxicity modelling approaches, such as the models of concentration addition and independent action and the mechanistic DEBtox framework have been previously shown as valuable tools for understanding and ultimately predicting joint toxicity. Here we apply these mixture models to investigate the potential to interpret the effects of semi-chronic binary mixture exposure for three bee species: Apis mellifera, Bombus terrestris and Osmia bicornis within potentiation and mixture toxicity experiments. In the potentiation studies, the effect of the insecticide dimethoate with added propiconazole fungicide and neonicotinoid insecticide clothianidin with added tau-fluvalinate pyrethroid acaricide showed no difference in toxicity compared to the single chemical alone. Clothianidin toxicity showed a small scale, but temporally conserved increase in exposure conducted in the presence of propiconazole, particularly for B. terrestris and O. bicornis, the latter showing a near three-fold increase in clothianidin toxicity in the presence of propiconazole. In the mixture toxicity studies, the dominant response patterns were of additivity, however, binary mixtures of clothianidin and dimethoate in A. mellifera, B. terrestris and male O. bicornis there was evidence of a predominant antagonistic interaction. Given the ubiquitous nature of exposures to multiple chemicals, there is an urgent need to consider mixture effects in pollinator risk assessments. Our analyses suggest that current models, particularly those that utilise time-series data, such as DEBtox, can be used to identify additivity as the dominant response pattern and also those examples of interactions, even when small-scale, that may need to be taken into account during risk assessment.

  19. Expanding the species and chemical diversity of Penicillium section Cinnamopurpurea

    DEFF Research Database (Denmark)

    Peterson, Stephen W.; Jurjević, Željko; Frisvad, Jens Christian

    2015-01-01

    isolates and sequenced. Two species in section Cinnamopurpurea are self-compatible sexual species, but the asexual species had polymorphic loci suggestive of sexual reproduction and variation in conidium size suggestive of ploidy level differences typical of heterothallism. Accordingly we use genealogical...... concordance analysis, a technique valid only in heterothallic organisms, for putatively asexual species. Seven new species were revealed in the analysis and are described here. Extrolite analysis showed that two of the new species, P. colei and P. monsserratidens produce the mycotoxin citreoviridin that has...

  20. Surrogate fuel formulation for light naphtha combustion in advanced combustion engines

    KAUST Repository

    Ahmed, Ahfaz

    2015-03-30

    Crude oil once recovered is further separated in to several distinct fractions to produce a range of energy and chemical products. One of the less processed fractions is light naphtha (LN), hence they are more economical to produce than their gasoline and diesel counterparts. Recent efforts have demonstrated usage of LN as transportation fuel for internal combustion engines with slight modifications. In this study, a multicomponent surrogate fuel has been developed for light naphtha fuel using a multi-variable nonlinear constrained optimization scheme. The surrogate, consisting of palette species n-pentane, 2-methylhexane, 2-methylbutane, n-heptane and toluene, was validated against the LN using ignition quality tester following ASTM D6890 methodology. Comparison of LN and the surrogate fuel demonstrated satisfactory agreement.

  1. Recent progress in gasoline surrogate fuels

    KAUST Repository

    Sarathy, Mani

    2017-12-06

    Petroleum-derived gasoline is currently the most widely used fuel for transportation propulsion. The design and operation of gasoline fuels is governed by specific physical and chemical kinetic fuel properties. These must be thoroughly understood in order to improve sustainable gasoline fuel technologies in the face of economical, technological, and societal challenges. For this reason, surrogate mixtures are formulated to emulate the thermophysical, thermochemical, and chemical kinetic properties of the real fuel, so that fundamental experiments and predictive simulations can be conducted. Early studies on gasoline combustion typically adopted single component or binary mixtures (n-heptane/isooctane) as surrogates. However, the last decade has seen rapid progress in the formulation and utilization of ternary mixtures (n-heptane/isooctane/toluene), as well as multicomponent mixtures that span the entire carbon number range of gasoline fuels (C4–C10). The increased use of oxygenated fuels (ethanol, butanol, MTBE, etc.) as blending components/additives has also motivated studies on their addition to gasoline fuels. This comprehensive review presents the available experimental and chemical kinetic studies which have been performed to better understand the combustion properties of gasoline fuels and their surrogates. Focus is on the development and use of surrogate fuels that emulate real fuel properties governing the design and operation of engines. A detailed analysis is presented for the various classes of compounds used in formulating gasoline surrogate fuels, including n-paraffins, isoparaffins, olefins, naphthenes, and aromatics. Chemical kinetic models for individual molecules and mixtures of molecules to emulate gasoline surrogate fuels are presented. Despite the recent progress in gasoline surrogate fuel combustion research, there are still major gaps remaining; these are critically discussed, as well as their implications on fuel formulation and engine

  2. Recent progress in gasoline surrogate fuels

    KAUST Repository

    Sarathy, Mani; Farooq, Aamir; Kalghatgi, Gautam T.

    2017-01-01

    Petroleum-derived gasoline is currently the most widely used fuel for transportation propulsion. The design and operation of gasoline fuels is governed by specific physical and chemical kinetic fuel properties. These must be thoroughly understood in order to improve sustainable gasoline fuel technologies in the face of economical, technological, and societal challenges. For this reason, surrogate mixtures are formulated to emulate the thermophysical, thermochemical, and chemical kinetic properties of the real fuel, so that fundamental experiments and predictive simulations can be conducted. Early studies on gasoline combustion typically adopted single component or binary mixtures (n-heptane/isooctane) as surrogates. However, the last decade has seen rapid progress in the formulation and utilization of ternary mixtures (n-heptane/isooctane/toluene), as well as multicomponent mixtures that span the entire carbon number range of gasoline fuels (C4–C10). The increased use of oxygenated fuels (ethanol, butanol, MTBE, etc.) as blending components/additives has also motivated studies on their addition to gasoline fuels. This comprehensive review presents the available experimental and chemical kinetic studies which have been performed to better understand the combustion properties of gasoline fuels and their surrogates. Focus is on the development and use of surrogate fuels that emulate real fuel properties governing the design and operation of engines. A detailed analysis is presented for the various classes of compounds used in formulating gasoline surrogate fuels, including n-paraffins, isoparaffins, olefins, naphthenes, and aromatics. Chemical kinetic models for individual molecules and mixtures of molecules to emulate gasoline surrogate fuels are presented. Despite the recent progress in gasoline surrogate fuel combustion research, there are still major gaps remaining; these are critically discussed, as well as their implications on fuel formulation and engine

  3. Experimental determination of the speciation, partitioning, and release of perrhenate as a chemical surrogate for pertechnetate from a sodalite-bearing multiphase ceramic waste form

    International Nuclear Information System (INIS)

    Pierce, E.M.; Lukens, W.W.; Fitts, J.P.; Jantzen, C.M.; Tang, G.

    2014-01-01

    Highlights: • Multiphase ceramic waste form is composed of primarily of nepheline, nosean, and sodalite. • Rhenium is in the 7+ oxidation state and has partitioned to a mixed Re-bearing sodalite phase. • Mechanism of corrosion for the multiphase matrix is similar to other silicate minerals. • A mixed-anion sodalite phases controls Re release in the multiphase waste forms. - Abstract: A key component to closing the nuclear fuel cycle is the storage and disposition of nuclear waste in geologic systems. Multiphase ceramic waste forms have been studied extensively as a potential host matrix for nuclear waste. Understanding the speciation, partitioning, and release behavior of radionuclides immobilized in multiphase ceramic waste forms is a critical aspect of developing the scientific and technical basis for nuclear waste management. In this study, we evaluated a sodalite-bearing multiphase ceramic waste form (i.e., fluidized-bed steam reform sodium aluminosilicate [FBSR NAS] product) as a potential host matrix for long-lived radionuclides, such as technetium ( 99 Tc). The FBSR NAS material consists primarily of nepheline (ideally NaAlSiO 4 ), anion-bearing sodalites (ideally M 8 [Al 6 Si 6 O 24 ]X 2 , where M refers to alkali and alkaline earth cations and X refers to monovalent anions), and nosean (ideally Na 8 [AlSiO 4 ] 6 SO 4 ). Bulk X-ray absorption fine structure analysis of the multiphase ceramic waste form, suggest rhenium (Re) is in the Re(VII) oxidation state and has partitioned to a Re-bearing sodalite phase (most likely a perrhenate sodalite Na 8 [Al 6 Si 6 O 24 ](ReO 4 ) 2 ). Rhenium was added as a chemical surrogate for 99 Tc during the FBSR NAS synthesis process. The weathering behavior of the FBSR NAS material was evaluated under hydraulically unsaturated conditions with deionized water at 90 °C. The steady-state Al, Na, and Si concentrations suggests the weathering mechanisms are consistent with what has been observed for other aluminosilicate

  4. Expanding the species and chemical diversity of Penicillium section Cinnamopurpurea.

    Directory of Open Access Journals (Sweden)

    Stephen W Peterson

    Full Text Available A set of isolates very similar to or potentially conspecific with an unidentified Penicillium isolate NRRL 735, was assembled using a BLAST search of ITS similarity among described (GenBank and undescribed Penicillium isolates in our laboratories. DNA was amplified from six loci of the assembled isolates and sequenced. Two species in section Cinnamopurpurea are self-compatible sexual species, but the asexual species had polymorphic loci suggestive of sexual reproduction and variation in conidium size suggestive of ploidy level differences typical of heterothallism. Accordingly we use genealogical concordance analysis, a technique valid only in heterothallic organisms, for putatively asexual species. Seven new species were revealed in the analysis and are described here. Extrolite analysis showed that two of the new species, P. colei and P. monsserratidens produce the mycotoxin citreoviridin that has demonstrated pharmacological activity against human lung tumors. These isolates could provide leads in pharmaceutical research.

  5. Novel view on predicting acute toxicity: Decomposing toxicity data in species vulnerability and chemical potency.

    NARCIS (Netherlands)

    Jager, D.T.; Posthuma, L.; Zwart, D.D.; van de Meent, D.

    2007-01-01

    Chemical risk assessment usually applies empirical methods to predict toxicant effects on different species. We propose a more mechanism-oriented approach, and introduce a method to decompose toxicity data in a contribution from the chemical (potency) and from the exposed species (vulnerability). We

  6. Surrogate waveform models

    Science.gov (United States)

    Blackman, Jonathan; Field, Scott; Galley, Chad; Scheel, Mark; Szilagyi, Bela; Tiglio, Manuel

    2015-04-01

    With the advanced detector era just around the corner, there is a strong need for fast and accurate models of gravitational waveforms from compact binary coalescence. Fast surrogate models can be built out of an accurate but slow waveform model with minimal to no loss in accuracy, but may require a large number of evaluations of the underlying model. This may be prohibitively expensive if the underlying is extremely slow, for example if we wish to build a surrogate for numerical relativity. We examine alternate choices to building surrogate models which allow for a more sparse set of input waveforms. Research supported in part by NSERC.

  7. Make the Most of the Data You've Got: Bayesian Models and a Surrogate Species Approach to Assessing Benefits of Upstream Migration Flows for the Endangered Australian Grayling.

    Science.gov (United States)

    Webb, J Angus; Koster, Wayne M; Stuart, Ivor G; Reich, Paul; Stewardson, Michael J

    2018-03-01

    Environmental water managers must make best use of allocations, and adaptive management is one means of improving effectiveness of environmental water delivery. Adaptive management relies on generation of new knowledge from monitoring and evaluation, but it is often difficult to make clear inferences from available monitoring data. Alternative approaches to assessment of flow benefits may offer an improved pathway to adaptive management. We developed Bayesian statistical models to inform adaptive management of the threatened Australian grayling (Prototroctes maraena) in the coastal Thomson River, South-East Victoria Australia. The models assessed the importance of flows in spring and early summer (migration flows) for upstream dispersal and colonization of juveniles of this diadromous species. However, Australian grayling young-of-year were recorded in low numbers, and models provided no indication of the benefit of migration flows. To overcome this limitation, we applied the same models to young-of-year of a surrogate species (tupong-Pseudaphritis urvilli)-a more common diadromous species expected to respond to flow similarly to Australian grayling-and found strong positive responses to migration flows. Our results suggest two complementary approaches to supporting adaptive management of Australian grayling. First, refine monitoring approaches to allow direct measurement of effects of migration flows, a process currently under way. Second, while waiting for improved data, further investigate the use of tupong as a surrogate species. More generally, alternative approaches to assessment can improve knowledge to inform adaptive management, and this can occur while monitoring is being revised to directly target environmental responses of interest.

  8. Chemical analysis of bioactive substances in seven siberian Saussurea species

    Science.gov (United States)

    Avdeeva, Elena; Reshetov, Yaroslav; Shurupova, Margarita; Zibareva, Larisa; Borisova, Evgeniia; Belousov, Mikhail

    2017-11-01

    Main groups of biologically active substances of seven siberian Saussurea species (S. controversa DC., S. latifolia Ledeb., S. parviflora (Poir.) DC., S. frolowii Ledeb, S. amara (L.) DC., S. salicifolia (L.) DC. and S. daurica Adams) have been studied using paper, thin-layer, performance liquid chromatography, IR spectroscopy, spectrophotometry and mass spectrometry with inductively coupled plasma. Siberian Saussurea species have a rich elemental composition and contain a variety of phenolic compounds, amino acids, polysaccharides. The majority of polysaccharides are accumulated by S. controversa, S. salicifolia and S. frolowii. These plants contain a significant amount of calcium that may be a species characteristic. All plants contain quercetin and its glycosides, in some species luteolin, kaempferol, glycosides of apigenin and myricetin were revealed. Phenolic acids with predominant content of caffeic, chlorogenic and cinnamic acids were found in all the species. The maximum amount of phenolic acids and flavonoids was determined in the grass of S. latifolia, S. controversa and S. daurica. Characteristic absorption bands of lactone carbonyl of sesquiterpenoids in IR spectrum found in S. latifolia, S. controversa, S. daurica, S. amara and S. salicifolia. HPLC / UV analysis showed that peaks with absorption maxima of 242-246 nm due to the presence of α,β-unsaturated ketone group in the structure of ecdysteroids were found in S. salicifolia, S. controversa, S. daurica and S. latifolia.

  9. Premixed flame chemistry of a gasoline primary reference fuel surrogate

    KAUST Repository

    Selim, Hatem

    2017-03-10

    Investigating the combustion chemistry of gasoline surrogate fuels promises to improve detailed reaction mechanisms used for simulating their combustion. In this work, the combustion chemistry of one of the simplest, but most frequently used gasoline surrogates – primary reference fuel 84 (PRF 84, 84 vol% iso-octane and 16 vol% n-heptane), has been examined in a stoichiometric premixed laminar flame. Time-of-flight mass spectrometry coupled with a vacuum ultraviolet (VUV) synchrotron light source for species photoionization was used. Reactants, major end-products, stable intermediates, free radicals, and isomeric species were detected and quantified. Numerical simulations were conducted using a detailed chemical kinetic model with the most recently available high temperature sub-mechanisms for iso-octane and heptane, built on the top of an updated pentane isomers model and AramcoMech 2.0 (C0C4) base chemistry. A detailed interpretation of the major differences between the mechanistic pathways of both fuel components is given. A comparison between the experimental and numerical results is depicted and rate of production and sensitivity analyses are shown for the species with considerable disagreement between the experimental and numerical findings.

  10. Chemical equilibrium of ablation materials including condensed species

    Science.gov (United States)

    Stroud, C. W.; Brinkley, K. L.

    1975-01-01

    Equilibrium is determined by finding chemical composition with minimum free energy. Method of steepest descent is applied to quadratic representation of free-energy surface. Solution is initiated by selecting arbitrary set of mole fractions, from which point on free-energy surface is computed.

  11. Combustion Kinetic Studies of Gasolines and Surrogates

    KAUST Repository

    Javed, Tamour

    2016-01-01

    . These measurements were performed in shock tubes and rapid compression machines over a wide range of experimental conditions (650 – 1250 K, 10 – 40 bar) relevant to internal combustion engines. Using the measured the data and chemical kinetic analyses, the surrogate

  12. Wood Chemical Composition in Species of Cactaceae: The Relationship between Lignification and Stem Morphology

    Science.gov (United States)

    Canché-Escamilla, Gonzalo; Soto-Hernández, Marcos

    2015-01-01

    In Cactaceae, wood anatomy is related to stem morphology in terms of the conferred support. In species of cacti with dimorphic wood, a unique process occurs in which the cambium stops producing wide-band tracheids (WBTs) and produces fibers; this is associated with the aging of individuals and increases in size. Stem support and lignification have only been studied in fibrous tree-like species, and studies in species with WBTs or dimorphic wood are lacking. In this study, we approach this process with a chemical focus, emphasizing the role of wood lignification. We hypothesized that the degree of wood lignification in Cactaceae increases with height of the species and that its chemical composition varies with wood anatomy. To test this, we studied the chemical composition (cellulose, hemicellulose, and lignin content) in 13 species (2 WBTs wood, 3 dimorphic, and 8 fibrous) with contrasting growth forms. We also analyzed lignification in dimorphic and fibrous species to determine the chemical features of WBTs and fibers and their relationship with stem support. The lignin contents were characterized by Fourier transform infrared spectroscopy and high performance liquid chromatography. We found that 11 species have a higher percentage (>35%) of lignin in their wood than other angiosperms or gymnosperms. The lignin chemical composition in fibrous species is similar to that of other dicots, but it is markedly heterogeneous in non-fibrous species where WBTs are abundant. The lignification in WBTs is associated with the resistance to high water pressure within cells rather than the contribution to mechanical support. Dimorphic wood species are usually richer in syringyl lignin, and tree-like species with lignified rays have more guaiacyl lignin. The results suggest that wood anatomy and lignin distribution play an important role in the chemical composition of wood, and further research is needed at the cellular level. PMID:25880223

  13. Wood chemical composition in species of Cactaceae: the relationship between lignification and stem morphology.

    Directory of Open Access Journals (Sweden)

    Jorge Reyes-Rivera

    Full Text Available In Cactaceae, wood anatomy is related to stem morphology in terms of the conferred support. In species of cacti with dimorphic wood, a unique process occurs in which the cambium stops producing wide-band tracheids (WBTs and produces fibers; this is associated with the aging of individuals and increases in size. Stem support and lignification have only been studied in fibrous tree-like species, and studies in species with WBTs or dimorphic wood are lacking. In this study, we approach this process with a chemical focus, emphasizing the role of wood lignification. We hypothesized that the degree of wood lignification in Cactaceae increases with height of the species and that its chemical composition varies with wood anatomy. To test this, we studied the chemical composition (cellulose, hemicellulose, and lignin content in 13 species (2 WBTs wood, 3 dimorphic, and 8 fibrous with contrasting growth forms. We also analyzed lignification in dimorphic and fibrous species to determine the chemical features of WBTs and fibers and their relationship with stem support. The lignin contents were characterized by Fourier transform infrared spectroscopy and high performance liquid chromatography. We found that 11 species have a higher percentage (>35% of lignin in their wood than other angiosperms or gymnosperms. The lignin chemical composition in fibrous species is similar to that of other dicots, but it is markedly heterogeneous in non-fibrous species where WBTs are abundant. The lignification in WBTs is associated with the resistance to high water pressure within cells rather than the contribution to mechanical support. Dimorphic wood species are usually richer in syringyl lignin, and tree-like species with lignified rays have more guaiacyl lignin. The results suggest that wood anatomy and lignin distribution play an important role in the chemical composition of wood, and further research is needed at the cellular level.

  14. Wood chemical composition in species of Cactaceae: the relationship between lignification and stem morphology.

    Science.gov (United States)

    Reyes-Rivera, Jorge; Canché-Escamilla, Gonzalo; Soto-Hernández, Marcos; Terrazas, Teresa

    2015-01-01

    In Cactaceae, wood anatomy is related to stem morphology in terms of the conferred support. In species of cacti with dimorphic wood, a unique process occurs in which the cambium stops producing wide-band tracheids (WBTs) and produces fibers; this is associated with the aging of individuals and increases in size. Stem support and lignification have only been studied in fibrous tree-like species, and studies in species with WBTs or dimorphic wood are lacking. In this study, we approach this process with a chemical focus, emphasizing the role of wood lignification. We hypothesized that the degree of wood lignification in Cactaceae increases with height of the species and that its chemical composition varies with wood anatomy. To test this, we studied the chemical composition (cellulose, hemicellulose, and lignin content) in 13 species (2 WBTs wood, 3 dimorphic, and 8 fibrous) with contrasting growth forms. We also analyzed lignification in dimorphic and fibrous species to determine the chemical features of WBTs and fibers and their relationship with stem support. The lignin contents were characterized by Fourier transform infrared spectroscopy and high performance liquid chromatography. We found that 11 species have a higher percentage (>35%) of lignin in their wood than other angiosperms or gymnosperms. The lignin chemical composition in fibrous species is similar to that of other dicots, but it is markedly heterogeneous in non-fibrous species where WBTs are abundant. The lignification in WBTs is associated with the resistance to high water pressure within cells rather than the contribution to mechanical support. Dimorphic wood species are usually richer in syringyl lignin, and tree-like species with lignified rays have more guaiacyl lignin. The results suggest that wood anatomy and lignin distribution play an important role in the chemical composition of wood, and further research is needed at the cellular level.

  15. Chemical score of different protein sources to four Macrobrachium species

    OpenAIRE

    Montoya-Martínez, Cynthia; Nolasco-Soria, Héctor; Carrillo-Farnés, Olimpia; Civera-Cerecedo, Roberto; Álvarez-González, Carlos; Vega-Villasante, Fernando

    2016-01-01

    Food production for aquaculture requires finding other protein sources or ingredients as potential alternatives in the formulation of aquaculture feeds, due to the shortage and high price of protein sources that are most commonly used. The aim of this analysis was to evaluate the relationship between the essential amino acids in 13 types of proteins available in the market with the essential amino acids found in the muscle of four of the most important farmed prawn species of the genus Macrob...

  16. Chemical and pharmacological investigation of Acacia and Santalum species

    DEFF Research Database (Denmark)

    Knudsen, Diana Jæger

    compounds from plants still have a huge potential for investigation for medicinal properties as possible drug leads. Humans have a long history of using plant medicine in treatments and indigenous cultures are a remarkable source for immense knowledge about plants and the uses of them - knowledge that has...... often only exists amongst members of communities or groups of the land where it has arisen. In this PhD project the three Australian plant species Acacia ligulata A.Cunn. ex Benth, Santalum spicatum (R.Br.) A.DC and Santalum lanceolatum R.Br were investigated for their bioactivity and chemistry...

  17. The Decomposition of Surrogate Fuel Molecules During Combustion

    National Research Council Canada - National Science Library

    Tsang, Wing; Manion, Jeffrey A

    2006-01-01

    This project is aimed at developing a chemical kinetic database consisting of the rate constants of fundamental single step reactions that describe the pyrolytic decomposition of surrogate fuels molecules...

  18. SeqAPASS: Predicting chemical susceptibility to threatened/endangered species

    Science.gov (United States)

    Conservation of a molecular target across species can be used as a line-of-evidence to predict the likelihood of chemical susceptibility. The web-based Sequence Alignment to Predict Across Species Susceptibility (SeqAPASS; https://seqapass.epa.gov/seqapass/) application was devel...

  19. The electrochemical generation of useful chemical species from lunar materials

    Science.gov (United States)

    Tsai, Kan J.; Kuchynka, Daniel J.; Sammells, Anthony F.

    1989-01-01

    The current status of work on an electrochemical technology for the simultaneous generation of oxygen and lithium from a Li2O containing molten salt (Li2O-LiCl-LiF) is discussed. The electrochemical cell utilizes an oxygen vacancy conducting solid electrolyte, yttria-stabilized zirconia, to effect separation between the oxygen evolving and lithium reduction half-cell reactions. The cell, which operates at 700 to 800 C, possesses rapid electrode kinetics at the lithium-alloy electrode with exchange current density values being greater than 60 mA/sq cm, showing high reversibility for this reaction. When used in the electrolytic mode, lithium produced at the negative electrode would be continuously removed from the cell for later use (under lunar conditions) as an easily storable reducting agent (compared to H2) for the chemical refining of lunar ores via the general reaction: 2Li + MO yields Li2O + M where MO represents a lunar ore. Emphasis to this time has been on the simulated lunar ore ilmenite (FeTiO3), which we have found becomes chemically reduced by Li at 432 C. Furthermore, both Fe2O3 and TiO2 have been reduced by Li to give the corresponding metal. This electrochemical approach provides a convenient route for producing metals under lunar conditions and oxygen for the continuous maintenance of human habitats on the Moon's surface. Because of the high reversibility of this electrochemical system, it has also formed the basis for the lithium-oxygen secondary battery. This secondary lithium-oxygen battery system posses the highest theoretical energy density yet investigated.

  20. Speciation and internal dosimetry: from chemical species to dosimetric models

    International Nuclear Information System (INIS)

    Paquet, F.; Frelon, S.; Cote, G.; Madic, C.

    2004-01-01

    Speciation studies refer to the distribution of species in a particular sample or matrix. These studies are necessary to improve the description, understanding and prediction of trace element kinetics and toxicity. In case of internal contamination with radionuclides, speciation studies could help to improve both the biokinetic and dosimetric models for radionuclides. There are different methods to approach the speciation of radionuclide in a biological system, depending on the degree of accuracy needed and the level of uncertainties accepted. Among them, computer modelling and experimental determination are complementary approaches. This paper describes what is known about speciation of actinides in blood, GI-tract, liver and skeleton and of their consequences in terms of internal dosimetry. The conclusion is that such studies provide very valuable data and should be targeted in the future on some specific tissues and biomolecules. (authors)

  1. DNA fingerprinting, biological and chemical investigation of certain Yucca species.

    Science.gov (United States)

    El Hawary, Seham; El Sayed, Abeer; Helmy, Maged W; El Naggar, El Moataz Bellah; Marzouk, Hanan S; Bassam, Samar M

    2018-01-05

    Yucca aloifolia, Y. aloifolia variegata, Y. elephantipes and Y. filamentosa were investigated. DNA sequencing was performed for the four plants and a genomic DNA fingerprint was obtained and provided. The cytotoxic activities against four human cancer cell lines were investigated. The ethanolic extracts of leaves of Y. aloifolia variegata prevailed, especially against liver cancer HepG-2 and breast cancer MCF-7. In vivo assessment of hepatoprotective activity in rats also revealed the hepatoprotective potential of the ethanolic extracts of the four plants against CCl 4 - induced rats' liver damage. Qualitative and quantitative analysis of the flavonoid and phenolic content of the promising species was performed using HPLC. The analysis identified and quantified 18 flavonoids and 19 phenolic acids in the different fractions of Y. aloifolia variegata, among which the major flavonoids were hesperidin and kaemp-3-(2-p-coumaroyl) glucose and the major phenolic acids were gallic acid and protocatechuic acid.

  2. Kaempferitrin from Uncaria guianensis (Rubiaceae) and its potential as a chemical marker for the species

    International Nuclear Information System (INIS)

    Valente, Ligia M.M.; Liechocki, Sally; Barboza, Rodolfo S.; Paixao, Djavan da; Bizarri, Carlos H.B.; Almeida, M. Beatriz S.; Benevides, Paulo J.C.; Siani, Antonio C.; Magalhaes, Alvicler

    2009-01-01

    Uncaria tomentosa (Willd.) DC. and U. guianensis (Aubl.) Gmel., known as cat's claw, are large woody vines native to the Amazonian and Central American rain forests. The species contain, in different proportions, indole and oxindole alkaloids, triterpenoid glycosides, sterols and proanthocyanidins. U. tomentosa can be chemically identified by its oxindole alkaloid profile and content, whereas U. guianensis has no satisfactorily established chemical markers. This work describes, for the first time, the isolation of kaempferol-3,7-O-(a)-dirhamnoside (kaempferitrin) in Uncaria species. Screening for this compound in leaves, stems or bark of both species through TLC and HPLC-DAD-MS showed the presence of kaempferitrin only in the leaves and stems of U. guianensis, at a ratio almost thirty six times greater in the leaves than in the stems. These results reveal the selectivity of U. guianensis to produce this bioactive flavonoid glycoside, and suggest this compound as a potential chemical marker for the species.(author)

  3. Chemical similarity and local community assembly in the species rich tropical genus Piper.

    Science.gov (United States)

    Salazar, Diego; Jaramillo, M Alejandra; Marquis, Robert J

    2016-11-01

    Community ecologists have strived to find mechanisms that mediate the assembly of natural communities. Recent evidence suggests that natural enemies could play an important role in the assembly of hyper-diverse tropical plant systems. Classic ecological theory predicts that in order for coexistence to occur, species differences must be maximized across biologically important niche dimensions. For plant-herbivore interactions, it has been recently suggested that, within a particular community, plant species that maximize the difference in chemical defense profiles compared to neighboring taxa will have a relative competitive advantage. Here we tested the hypothesis that plant chemical diversity can affect local community composition in the hyper-diverse genus Piper at a lowland wet forest location in Costa Rica. We first characterized the chemical composition of 27 of the most locally abundant species of Piper. We then tested whether species with different chemical compositions were more likely to coexist. Finally, we assessed the degree to which Piper phylogenetic relationships are related to differences in secondary chemical composition and community assembly. We found that, on average, co-occurring species were more likely to differ in chemical composition than expected by chance. Contrary to expectations, there was no phylogenetic signal for overall secondary chemical composition. In addition we found that species in local communities were, on average, more phylogenetically closely related than expected by chance, suggesting that functional traits other than those measured here also influence local assembly. We propose that selection by herbivores for divergent chemistries between closely related species facilitates the coexistence of a high diversity of congeneric taxa via apparent competition. © 2016 by the Ecological Society of America.

  4. Chemical composition and antioxidant activity of certain Morus species

    Science.gov (United States)

    Imran, Mohammad; Khan, Hamayun; Shah, Mohibullah; Khan, Rasool; Khan, Faridullah

    2010-01-01

    In the present work, the fruits of four Morus species, namely Morus alba (white mulberry), Morus nigra (black mulberry), Morus laevigata (large white fruit), and Morus laevigata (large black fruit), were analyzed for proximate composition, essential minerals, and antioxidant potentials. For this purpose, the ripe fruits were collected from the northern regions of Pakistan. The major nutritional components (moisture, ash, lipids, proteins, fibres, carbohydrates, and total sugar) were found to be in the suitable range along with good computed energy. Total dry weight, pH, and titratable acidity (percent citric acid) were (17.60±1.94)–(21.97±2.34) mg/100 g, (3.20±0.07)–(4.78±0.15), and (0.84±0.40)%–(2.00±0.08)%, respectively. Low riboflavin (vitamin B2) and niacin (vitamin B3) contents were recorded in all the fruits, while ascorbic acid (vitamin C) was in the range from (15.20±1.25) to (17.03±1.71) mg/100 g fresh weight (FW). The mulberry fruits were rich with regard to the total phenol and alkaloid contents, having values of (880±7.20)–(1650±12.25) mg/100 g FW and (390±.22)–(660±5.25) mg/100 g FW, respectively. Sufficient quantities of essential macro-(K, Ca, Mg, and Na) and micro-(Fe, Zn, and Ni) elements were found in all the fruits. K was the predominant element with concentration ranging from (1270±9.36) to (1731±11.50) mg/100 g, while Ca, Na, and Mg contents were (440±3.21)–(576±7.37), (260±3.86)–(280±3.50), and (24±3.51)–(360±4.20) mg/100 g, respectivly. The decreasing order of micro-minerals was Fe>Zn>Ni. The radical scavenging activity of methanolic extract of fruits was concentration-dependent and showed a correlation with total phenolic constituents of the respective fruits. Based on the results obtained, mulberry fruits were found to serve as a potential source of food diet and natural antioxidants. PMID:21121077

  5. Chemical generation of volatile species of copper – Optimization, efficiency and investigation of volatile species nature

    Czech Academy of Sciences Publication Activity Database

    Šoukal, Jakub; Benada, Oldřich; Matoušek, Tomáš; Dědina, Jiří; Musil, Stanislav

    2017-01-01

    Roč. 977, JUL (2017), s. 10-19 ISSN 0003-2670 Institutional support: RVO:68081715 ; RVO:61388971 Keywords : generation of volatile species * copper * analytical atomic spectrometry Subject RIV: CB - Analytical Chemistry, Separation; EE - Microbiology, Virology (MBU-M) OBOR OECD: Analytical chemistry; Microbiology (MBU-M) Impact factor: 4.950, year: 2016

  6. Chemical, Bioactive, and Antioxidant Potential of Twenty Wild Culinary Mushroom Species

    Science.gov (United States)

    Sharma, S. K.; Gautam, N.

    2015-01-01

    The chemical, bioactive, and antioxidant potential of twenty wild culinary mushroom species being consumed by the people of northern Himalayan regions has been evaluated for the first time in the present study. Nutrients analyzed include protein, crude fat, fibres, carbohydrates, and monosaccharides. Besides, preliminary study on the detection of toxic compounds was done on these species. Bioactive compounds evaluated are fatty acids, amino acids, tocopherol content, carotenoids (β-carotene, lycopene), flavonoids, ascorbic acid, and anthocyanidins. Fruitbodies extract of all the species was tested for different types of antioxidant assays. Although differences were observed in the net values of individual species all the species were found to be rich in protein, and carbohydrates and low in fat. Glucose was found to be the major monosaccharide. Predominance of UFA (65–70%) over SFA (30–35%) was observed in all the species with considerable amounts of other bioactive compounds. All the species showed higher effectiveness for antioxidant capacities. PMID:26199938

  7. Chemical, Bioactive, and Antioxidant Potential of Twenty Wild Culinary Mushroom Species

    Directory of Open Access Journals (Sweden)

    S. K. Sharma

    2015-01-01

    Full Text Available The chemical, bioactive, and antioxidant potential of twenty wild culinary mushroom species being consumed by the people of northern Himalayan regions has been evaluated for the first time in the present study. Nutrients analyzed include protein, crude fat, fibres, carbohydrates, and monosaccharides. Besides, preliminary study on the detection of toxic compounds was done on these species. Bioactive compounds evaluated are fatty acids, amino acids, tocopherol content, carotenoids (β-carotene, lycopene, flavonoids, ascorbic acid, and anthocyanidins. Fruitbodies extract of all the species was tested for different types of antioxidant assays. Although differences were observed in the net values of individual species all the species were found to be rich in protein, and carbohydrates and low in fat. Glucose was found to be the major monosaccharide. Predominance of UFA (65–70% over SFA (30–35% was observed in all the species with considerable amounts of other bioactive compounds. All the species showed higher effectiveness for antioxidant capacities.

  8. Chemical, Bioactive, and Antioxidant Potential of Twenty Wild Culinary Mushroom Species.

    Science.gov (United States)

    Sharma, S K; Gautam, N

    2015-01-01

    The chemical, bioactive, and antioxidant potential of twenty wild culinary mushroom species being consumed by the people of northern Himalayan regions has been evaluated for the first time in the present study. Nutrients analyzed include protein, crude fat, fibres, carbohydrates, and monosaccharides. Besides, preliminary study on the detection of toxic compounds was done on these species. Bioactive compounds evaluated are fatty acids, amino acids, tocopherol content, carotenoids (β-carotene, lycopene), flavonoids, ascorbic acid, and anthocyanidins. Fruitbodies extract of all the species was tested for different types of antioxidant assays. Although differences were observed in the net values of individual species all the species were found to be rich in protein, and carbohydrates and low in fat. Glucose was found to be the major monosaccharide. Predominance of UFA (65-70%) over SFA (30-35%) was observed in all the species with considerable amounts of other bioactive compounds. All the species showed higher effectiveness for antioxidant capacities.

  9. Various chemical strategies to deceive ants in three Arhopala species (lepidoptera: Lycaenidae exploiting Macaranga myrmecophytes.

    Directory of Open Access Journals (Sweden)

    Yoko Inui

    Full Text Available Macaranga myrmecophytes (ant-plants are generally well protected from herbivore attacks by their symbiotic ants (plant-ants. However, larvae of Arhopala (Lepidoptera: Lycaenidae species survive and develop on specific Macaranga ant-plant species without being attacked by the plant-ants of their host species. We hypothesized that Arhopala larvae chemically mimic or camouflage themselves with the ants on their host plant so that the larvae are accepted by the plant-ant species of their host. Chemical analyses of cuticular hydrocarbons showed that chemical congruency varied among Arhopala species; A. dajagaka matched well the host plant-ants, A. amphimuta did not match, and unexpectedly, A. zylda lacked hydrocarbons. Behaviorally, the larvae and dummies coated with cuticular chemicals of A. dajagaka were well attended by the plant-ants, especially by those of the host. A. amphimuta was often attacked by all plant-ants except for the host plant-ants toward the larvae, and those of A. zylda were ignored by all plant-ants. Our results suggested that conspicuous variations exist in the chemical strategies used by the myrmecophilous butterflies that allow them to avoid ant attack and be accepted by the plant-ant colonies.

  10. Chemical investigation on wood tree species in a temperate forest, east-northern Romania

    Directory of Open Access Journals (Sweden)

    Teaca, C. A.

    2007-02-01

    Full Text Available A quantitative evaluation of wood chemical components for some tree species in a forest area from east-northern Romania is presented here, through a comparative study from 1964 to 2000. Investigation upon the wood tree-rings in a Quercus robur L. tree species, as a dominant species, as regards its chemical composition and structure of the natural polymer constituents - cellulose and lignin - was also performed through chemical methods to separate the main wood components, FT-IR spectroscopy, and thermogravimetry. Having in view the impact of climate and external factors (such as pollutant depositions, some possible correlations between wood chemical composition and its further use can be made. The FT-IR spectra give evidence of differences in the frequency domains of 3400-2900 cm-1 and 1730-1640 cm-1, due to some interactions between the chemical groups (OH, C=O. The crystallinity index of cellulose presents variations in the oak wood tree-rings. Thermogravimetry analyses show different behaviour of cellulose at thermal decomposition, as a function of radial growth and tree’s height. A preliminary chemical investigation of oak wood sawdust shows a relatively high content of mineral elements (ash, compared with a previous study performed in 1964, fact that may indicate an intense drying process of the oak tree, a general phenomenon present in European forests for this species.

  11. Can species-specific prey responses to chemical cues explain prey susceptibility to predation?

    Science.gov (United States)

    Šmejkal, Marek; Ricard, Daniel; Sajdlová, Zuzana; Čech, Martin; Vejřík, Lukáš; Blabolil, Petr; Vejříková, Ivana; Prchalová, Marie; Vašek, Mojmír; Souza, Allan T; Brönmark, Christer; Peterka, Jiří

    2018-05-01

    The perception of danger represents an essential ability of prey for gaining an informational advantage over their natural enemies. Especially in complex environments or at night, animals strongly rely on chemoreception to avoid predators. The ability to recognize danger by chemical cues and subsequent adaptive responses to predation threats should generally increase prey survival. Recent findings suggest that European catfish ( Silurus glanis ) introduction induce changes in fish community and we tested whether the direction of change can be attributed to differences in chemical cue perception. We tested behavioral response to chemical cues using three species of freshwater fish common in European water: rudd ( Scardinius erythrophthalmus ), roach ( Rutilus rutilus ), and perch ( Perca fluviatilis ). Further, we conducted a prey selectivity experiment to evaluate the prey preferences of the European catfish. Roach exhibited the strongest reaction to chemical cues, rudd decreased use of refuge and perch did not alter any behavior in the experiment. These findings suggest that chemical cue perception might be behind community data change and we encourage collecting more community data of tested prey species before and after European catfish introduction to test the hypothesis. We conclude that used prey species can be used as a model species to verify whether chemical cue perception enhances prey survival.

  12. Developments in Surrogating Methods

    Directory of Open Access Journals (Sweden)

    Hans van Dormolen

    2005-11-01

    Full Text Available In this paper, I would like to talk about the developments in surrogating methods for preservation. My main focus will be on the technical aspects of preservation surrogates. This means that I will tell you something about my job as Quality Manager Microfilming for the Netherlands’ national preservation program, Metamorfoze, which is coordinated by the National Library. I am responsible for the quality of the preservation microfilms, which are produced for Metamorfoze. Firstly, I will elaborate on developments in preservation methods in relation to the following subjects: · Preservation microfilms · Scanning of preservation microfilms · Preservation scanning · Computer Output Microfilm. In the closing paragraphs of this paper, I would like to tell you something about the methylene blue test. This is an important test for long-term storage of preservation microfilms. Also, I will give you a brief report on the Cellulose Acetate Microfilm Conference that was held in the British Library in London, May 2005.

  13. Organic reactions for the electrochemical and photochemical production of chemical fuels from CO2--The reduction chemistry of carboxylic acids and derivatives as bent CO2 surrogates.

    Science.gov (United States)

    Luca, Oana R; Fenwick, Aidan Q

    2015-11-01

    The present review covers organic transformations involved in the reduction of CO2 to chemical fuels. In particular, we focus on reactions of CO2 with organic molecules to yield carboxylic acid derivatives as a first step in CO2 reduction reaction sequences. These biomimetic initial steps create opportunities for tandem electrochemical/chemical reductions. We draw parallels between long-standing knowledge of CO2 reactivity from organic chemistry, organocatalysis, surface science and electrocatalysis. We point out some possible non-faradaic chemical reactions that may contribute to product distributions in the production of solar fuels from CO2. These reactions may be accelerated by thermal effects such as resistive heating and illumination. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Utilization of chemical derivatives in activation analysis

    International Nuclear Information System (INIS)

    Ehmann, W.D.

    1990-01-01

    Derivative activation analysis (DAA) is a method to enhance the sensitivity of nuclear activation analysis for the more elusive elements. It may also allow a degree of chemical speciation for the element of interest. DAA uses a preirradiation chemical reaction on the sample to initiate the formation of, or an exchange with, a chemical complex which contains a surrogate element, M. As a result, the amount of the element or the chemical species to be determined, X, is now represented by measurement of the amount of the surrogate element, M, that is made part of, or released by the complex species. The surrogate element is selected for its superior properties for nuclear activation analysis and the absence of interference reaction in its final determination by instrumental neutron activation analysis (INAA) after some preconcentration or separation chemistry. Published DAA studies have been limited to neutron activation analysis. DAA can offer the analyst some important advantages. It can determine elements, functional groups, or chemical species which cannot be determined directly by INAA, fast neutron activation analysis (FNAA), prompt gamma neutron activation analysis (PGNAA), or charged particle activation analysis (CPAA) procedures. When compared with conventional RNAA, there are fewer precautions with respect to handling of intensely radioactive samples, since the chemistry is done before the irradiation. The preirradiation chemistry may also eliminate many interferences that might occur in INAA and, through use of an appropriate surrogate element, can place the analytical gamma-ray line in an interference-free region of the gamma-ray spectrum

  15. Computing multi-species chemical equilibrium with an algorithm based on the reaction extents

    DEFF Research Database (Denmark)

    Paz-Garcia, Juan Manuel; Johannesson, Björn; Ottosen, Lisbeth M.

    2013-01-01

    -negative constrains. The residual function, representing the distance to the equilibrium, is defined from the chemical potential (or Gibbs energy) of the chemical system. Local minimums are potentially avoided by the prioritization of the aqueous reactions with respect to the heterogeneous reactions. The formation......A mathematical model for the solution of a set of chemical equilibrium equations in a multi-species and multiphase chemical system is described. The computer-aid solution of model is achieved by means of a Newton-Raphson method enhanced with a line-search scheme, which deals with the non...... and release of gas bubbles is taken into account in the model, limiting the concentration of volatile aqueous species to a maximum value, given by the gas solubility constant.The reaction extents are used as state variables for the numerical method. As a result, the accepted solution satisfies the charge...

  16. Chemical review and studies related to species from the genus Tynanthus (Bignoniaceae

    Directory of Open Access Journals (Sweden)

    Fernanda Colombi Cansian

    2015-09-01

    Full Text Available Species from the Bignoniaceae Family, including the genus Tynanthus, are very prevalent in the tropical Americas, with specimens found in a large part of the Brazilian territory. These plants are commonly used in traditional medicine for several purposes, and some studies have described their chemical structure, in addition to other reports related to some species from this genus. This review aimed to gather information from published works concerning species of the genus Tynanthus, as well as to detect flaws in research related to these plants, which may have great biological and pharmaceutical importance. Also, this review points out some common chemical characteristics of these species, providing information that may help new researchers to improve their knowledge about these plants.

  17. Exudate Chemical Profiles Derived from Lespedeza and Other Tallgrass Prairie Plant Species

    Science.gov (United States)

    2017-05-01

    Chemical Profiles Derived from Lespedeza and Other Tall- grass Prairie Plant Species. ERDC TN-17-1. Vicksburg, MS: U.S. Army Engineer Re- search and...200-1-52. Washington, DC: U.S. Army Corps of Engineers Headquarters, Civil Works. https://www.wbdg.org/ffc/army-coe/public-works-technical-bulletins...ERDC TN-17-1 May 2017 Approved for public release; distribution is unlimited. Exudate Chemical Profiles Derived from Lespedeza and Other

  18. Toward systems metabolic engineering of Aspergillus and Pichia species for the production of chemicals and biofuels

    DEFF Research Database (Denmark)

    Caspeta, Luis; Nielsen, Jens

    2013-01-01

    trends in systems biology of Aspergillus and Pichia species, highlighting the relevance of these developments for systems metabolic engineering of these organisms for the production of hydrolytic enzymes, biofuels and chemicals from biomass. Metabolic engineering is moving from traditional methods...... for the production of hydrolytic enzymes, biofuels and chemicals from biomass. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim....

  19. Chemical, Bioactive, and Antioxidant Potential of Twenty Wild Culinary Mushroom Species

    OpenAIRE

    Sharma, S. K.; Gautam, N.

    2015-01-01

    The chemical, bioactive, and antioxidant potential of twenty wild culinary mushroom species being consumed by the people of northern Himalayan regions has been evaluated for the first time in the present study. Nutrients analyzed include protein, crude fat, fibres, carbohydrates, and monosaccharides. Besides, preliminary study on the detection of toxic compounds was done on these species. Bioactive compounds evaluated are fatty acids, amino acids, tocopherol content, carotenoids (β-carotene, ...

  20. Short-lived long non-coding RNAs as surrogate indicators for chemical exposure and LINC00152 and MALAT1 modulate their neighboring genes.

    Directory of Open Access Journals (Sweden)

    Hidenori Tani

    Full Text Available Whole transcriptome analyses have revealed a large number of novel long non-coding RNAs (lncRNAs. Although accumulating evidence demonstrates that lncRNAs play important roles in regulating gene expression, the detailed mechanisms of action of most lncRNAs remain unclear. We previously reported that a novel class of lncRNAs with a short half-life (t1/2 < 4 h in HeLa cells, termed short-lived non-coding transcripts (SLiTs, are closely associated with physiological and pathological functions. In this study, we focused on 26 SLiTs and nuclear-enriched abundant lncRNA, MALAT1(t1/2 of 7.6 h in HeLa cells in neural stem cells (NSCs derived from human induced pluripotent stem cells, and identified four SLiTs (TUG1, GAS5, FAM222-AS1, and SNHG15 that were affected by the following typical chemical stresses (oxidative stress, heavy metal stress and protein synthesis stress. We also found the expression levels of LINC00152 (t1/2 of 2.1 h in NSCs, MALAT1 (t1/2 of 1.8 h in NSCs, and their neighboring genes were elevated proportionally to the chemical doses. Moreover, we confirmed that the overexpression of LINC00152 or MALAT1 upregulated the expressions of their neighboring genes even in the absence of chemical stress. These results reveal that LINC00152 and MALAT1 modulate their neighboring genes, and thus provide a deeper understanding of the functions of lncRNAs.

  1. Validity of fish, birds and mammals as surrogates for amphibians and reptiles in pesticide toxicity assessment.

    Science.gov (United States)

    Ortiz-Santaliestra, Manuel E; Maia, Joao P; Egea-Serrano, Andrés; Lopes, Isabel

    2018-02-28

    Amphibians and reptiles are the two most endangered groups of vertebrates. Environmental pollution by pesticides is recognised as one of the major factors threatening populations of these groups. However, the effects of pesticides on amphibians and reptiles have been studied for few substances, which is partly related to the fact that these animals are not included in the mandatory toxicity testing conducted as part of environmental risk assessments of pesticides. Whether risks of pesticides to amphibians and reptiles are addressed by surrogate taxa used in risk assessment is currently under debate. In order to develop a scientifically sound and robust risk assessment scheme, information needs to be gathered to examine whether fish, birds and mammals are valid surrogates for amphibians and reptiles. We updated a systematic review of scientific literature that was recently published compiling toxicity data on amphibians and reptiles. The outcome of this review was analysed with the purposes to (1) compare endpoints from amphibians and reptiles with the available information from fish, birds and mammals, and (2) develop species sensitivity distributions (SSDs) for those substances tested in at least six amphibian species (no substances were found tested in at least six reptile species) to identify a candidate amphibian model species to be used as surrogate in risk assessment. A positive correlation was found between toxicity recorded on fish and amphibians, the former revealing, in general, to be more sensitive than the latter to waterborne pollutants. In the terrestrial environment, although birds and mammals were more sensitive than amphibians and reptiles to at least 60% of tested substances, just a few weak significant correlations were observed. As a general rule, homoeothermic vertebrates are not good surrogates for reptiles and terrestrial amphibians in pesticide risk assessment. However, some chemical-dependent trends were detected, with pyrethroids and

  2. Chemical composition, mineral content and amino acid and lipid profiles in bones from various fish species.

    Science.gov (United States)

    Toppe, Jogeir; Albrektsen, Sissel; Hope, Britt; Aksnes, Anders

    2007-03-01

    The chemical composition, content of minerals and the profiles of amino acids and fatty acids were analyzed in fish bones from eight different species of fish. Fish bones varied significantly in chemical composition. The main difference was lipid content ranging from 23 g/kg in cod (Gadus morhua) to 509 g/kg in mackerel (Scomber scombrus). In general fatty fish species showed higher lipid levels in the bones compared to lean fish species. Similarly, lower levels of protein and ash were observed in bones from fatty fish species. Protein levels differed from 363 g/kg lipid free dry matter (dm) to 568 g/kg lipid free dm with a concomitant inverse difference in ash content. Ash to protein ratio differed from 0.78 to 1.71 with the lowest level in fish that naturally have highest swimming and physical activity. Saithe (Pollachius virens) and salmon (Salmo salar) were found to be significantly different in the levels of lipid, protein and ash, and ash/protein ratio in the bones. Only small differences were observed in the level of amino acids although species specific differences were observed. The levels of Ca and P in lipid free fish bones were about the same in all species analyzed. Fatty acid profile differed in relation to total lipid levels in the fish bones, but some minor differences between fish species were observed.

  3. Meet the surrogate fish

    International Nuclear Information System (INIS)

    Johnson, Bob; Neitzel, Duane; Moxon, Suzanne

    1999-01-01

    This article gives details of the US Department of Energy's innovative research into the development of a sensor system that will work as a surrogate fish to provide information to aid the design of fish-friendly turbines for hydroelectric power plants. The selection of the dams for the testing of sensor fish, the release and recovery of the sensor fish, the recording of the physical forces exerted on fish as they pass through the turbines, and use of the information gathered to build more sensor fish are discussed. Fish investigations conducted at the Pacific Northwest National Laboratory are briefly described. (UK)

  4. Systematic Approach to Calculate the Concentration of Chemical Species in Multi-Equilibrium Problems

    Science.gov (United States)

    Baeza-Baeza, Juan Jose; Garcia-Alvarez-Coque, Maria Celia

    2011-01-01

    A general systematic approach is proposed for the numerical calculation of multi-equilibrium problems. The approach involves several steps: (i) the establishment of balances involving the chemical species in solution (e.g., mass balances, charge balance, and stoichiometric balance for the reaction products), (ii) the selection of the unknowns (the…

  5. Investigation of microalgae HTL fuel effects on diesel engine performance and exhaust emissions using surrogate fuels

    International Nuclear Information System (INIS)

    Hossain, Farhad M.; Nabi, Md. Nurun; Rainey, Thomas J.; Bodisco, Timothy; Rahman, Md. Mostafizur; Suara, Kabir; Rahman, S.M.A.; Van, Thuy Chu; Ristovski, Zoran; Brown, Richard J.

    2017-01-01

    Highlights: • Development of a microalgae HTL surrogate of biocrude fuel using chemical compounds. • Physiochemical properties of surrogate blends were analysed. • Experimentally investigated diesel engine performance and emissions using surrogate fuels. • No significant changes in engine performance were observed with HTL surrogate blends. • Major emissions including PM, PN and CO were reduced significantly with increasing of NOx emission. - Abstract: This paper builds on previous work using surrogate fuel to investigate advanced internal combustion engine fuels. To date, a surrogate fuel of this nature has not been used for microalgae hydrothermal liquefaction (HTL) biocrude. This research used five different chemical groups found in microalgae HTL biocrude to design a surrogate fuel. Those five chemical groups constitute around 65% (by weight) of a microalgae biocrude produced by HTL. Weight percentage of the microalgae HTL biocrude chemical compounds were used to design the surrogate fuel, which was miscible with diesel at all percentages. The engine experiments were conducted on a EURO IIIA turbocharged common-rail direct-injection six-cylinder diesel engine to test engine performance and emissions. Exhaust emissions, including particulate matter and other gaseous emissions, were measured with the surrogate fuel and a reference diesel fuel. Experimental results showed that without significantly deteriorating engine performance, lower particulate mass, particulate number and CO emissions were observed with a penalty in NOx emissions for all surrogate blends compared to those of the reference diesel.

  6. Chemical profiles of body surfaces and nests from six Bornean stingless bee species.

    Science.gov (United States)

    Leonhardt, Sara Diana; Blüthgen, Nico; Schmitt, Thomas

    2011-01-01

    Stingless bees (Apidae: Meliponini) are the most diverse group of Apid bees and represent common pollinators in tropical ecosystems. Like honeybees they live in large eusocial colonies and rely on complex chemical recognition and communication systems. In contrast to honeybees, their ecology and especially their chemical ecology have received only little attention, particularly in the Old World. We previously have analyzed the chemical profiles of six paleotropical stingless bee species from Borneo and revealed the presence of species-specific cuticular terpenes- an environmentally derived compound class so far unique among social insects. Here, we compared the bees' surface profiles to the chemistry of their nest material. Terpenes, alkanes, and alkenes were the dominant compound groups on both body surfaces and nest material. However, bee profiles and nests strongly differed in their chemical composition. Body surfaces thus did not merely mirror nests, rendering a passive compound transfer from nests to bees unlikely. The difference between nests and bees was particularly pronounced when all resin-derived compounds (terpenes) were excluded and only genetically determined compounds were considered. When terpenes were included, bee profiles and nest material still differed, because whole groups of terpenes (e.g., sesquiterpenes) were found in nest material of some species, but missing in their chemical profile, indicating that bees are able to influence the terpene composition both in their nests and on their surfaces.

  7. Mobility and Attenuation Dynamics of Potentially Toxic Chemical Species at an Abandoned Copper Mine Tailings Dump

    Directory of Open Access Journals (Sweden)

    Wilson Mugera Gitari

    2018-02-01

    Full Text Available Large volumes of disposed mine tailings abound in several regions of South Africa, as a consequence of unregulated, unsustainable long years of mining activities. Tailings dumps occupy a large volume of valuable land, and present a potential risk for aquatic systems, through leaching of potentially toxic chemical species. This paper reports on the evaluation of the geochemical processes controlling the mobility of potentially toxic chemical species within the tailings profile, and their potential risk with regard to surface and groundwater systems. Combination of X-ray fluorescence (XRF, X-ray diffraction (XRD, and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS techniques, show that the tailing profiles are uniform, weakly altered, and vary slightly with depth in both physical and geochemical properties, as well as mineralogical composition. Mineralogical analysis showed the following order of abundance: quartz > epidote > chlorite > muscovite > calcite > hematite within the tailings profiles. The neutralization of the dominant alumino-silicate minerals and the absence of sulfidic minerals, have produced medium alkaline pH conditions (7.97–8.37 at all depths and low concentrations of dissolved Cu (20.21–47.9 µg/L, Zn (0.88–1.80 µg/L, Pb (0.27–0.34 µg/L, and SO42− (15.71–55.94 mg/L in the tailings profile leachates. The relative percentage leach for the potentially toxic chemical species was low in the aqueous phase (Ni 0.081%, Cu 0.006%, and Zn 0.05%. This indicates that the transport load of potentially toxic chemical species from tailings to the aqueous phase is very low. The precipitation of secondary hematite has an important known ability to trap and attenuate the mobility of potentially toxic chemical species (Cu, Zn, and Pb by adsorption on the surface area. Geochemical modelling MINTEQA2 showed that the tailings leachates were below saturation regarding oxyhydroxide minerals, but oversaturated with Cu

  8. Physico-chemical thresholds in the distribution of fish species among French lakes

    Directory of Open Access Journals (Sweden)

    Roubeix Vincent

    2017-01-01

    Full Text Available The management of lakes requires the definition of physico-chemical thresholds to be used for ecosystem preservation or restoration. According to the European Water Framework Directive, the limits between physico-chemical quality classes must be set consistently with biological quality elements. One way to do this consists in analyzing the response of aquatic communities to environmental gradients across monitoring sites and in identifying ecological community thresholds, i.e. zones in the gradients where the species turnover is the highest. In this study, fish data from 196 lakes in France were considered to derive ecological thresholds using the multivariate method of gradient forest. The analysis was performed on 25 species and 36 environmental parameters. The results revealed the highest importance of maximal water temperature in the distribution of fish species. Other important parameters included geographical factors, dissolved organic carbon concentration and water transparency, while nutrients appeared to have low influence. In spite of the diversity of species responses to the gradients, community thresholds were detected in the gradients of the most important physico-chemical parameters and of total phosphorus and nitrate concentrations as well. The thresholds identified in such macroecological study may highlight new patterns of species natural distribution and improve niche characterization. Moreover, when factors that may be influenced by human activities are involved, the thresholds could be used to set environmental standards for lake preservation.

  9. Chemically and size-resolved particulate matter dry deposition on stone and surrogate surfaces inside and outside the low emission zone of Milan: application of a newly developed "Deposition Box".

    Science.gov (United States)

    Ferrero, Luca; Casati, Marco; Nobili, Lara; D'Angelo, Luca; Rovelli, Grazia; Sangiorgi, Giorgia; Rizzi, Cristiana; Perrone, Maria Grazia; Sansonetti, Antonio; Conti, Claudia; Bolzacchini, Ezio; Bernardi, Elena; Vassura, Ivano

    2018-04-01

    The collection of atmospheric particles on not-filtering substrates via dry deposition, and the subsequent study of the particle-induced material decay, is trivial due to the high number of variables simultaneously acting on the investigated surface. This work reports seasonally resolved data of chemical composition and size distribution of particulate matter deposed on stone and surrogate surfaces obtained using a new method, especially developed at this purpose. A "Deposition Box" was designed allowing the particulate matter dry deposition to occur selectively removing, at the same time, variables that can mask the effect of airborne particles on material decay. A pitched roof avoided rainfall and wind variability; a standardised gentle air exchange rate ensured a continuous "sampling" of ambient air leaving unchanged the sampled particle size distribution and, at the same time, leaving quite calm condition inside the box, allowing the deposition to occur. Thus, the "Deposition Box" represents an affordable tool that can be used complementary to traditional exposure systems. With this system, several exposure campaigns, involving investigated stone materials (ISMs) (Carrara Marble, Botticino limestone, Noto calcarenite and Granite) and surrogate (Quartz, PTFE, and Aluminium) substrates, have been performed in two different sites placed in Milan (Italy) inside and outside the low emission zone. Deposition rates (30-90 μg cm -2  month -1 ) showed significant differences between sites and seasons, becoming less evident considering long-period exposures due to a positive feedback on the deposition induced by the deposited particles. Similarly, different stone substrates influenced the deposition rates too. The collected deposits have been observed with optical and scanning electron microscopes and analysed by ion chromatography. Ion deposition rates were similar in the two sites during winter, whereas it was greater outside the low emission zone during summer and

  10. USE OF AMAZONIAN SPECIES FOR AGING DISTILLED BEVERAGES: PHYSICAL AND CHEMICAL WOOD ANALYSIS

    Directory of Open Access Journals (Sweden)

    Jonnys Paz Castro

    2015-06-01

    Full Text Available The process of storing liquor in wooden barrels is a practice that aims to improve the sensory characteristics, such as color, aroma and flavor, of the beverage. The quality of the liquor stored in these barrels depends on wood characteristics such as density, permeability, chemical composition, anatomy, besides the wood heat treatment used to fabricate the barrels. Brazil has a great diversity of forests, mainly in the north, in the Amazon. This region is home to thousands of tree species, but is limited to the use of only a few native species to store liquors. The objective of this study was to determine some of the physical and chemical characteristics for four Amazon wood species. The results obtained in this study will be compared with others from woods that are traditionally used for liquor storage. The species studied were angelim-pedra (Hymenolobium petraeum Ducke cumarurana (Dipteryx polyphylla (Huber Ducke, jatobá (Hymenaea courbaril L. and louro-vermelho (Nectandra rubra (Mez CK Allen. The trees were collected from Precious Woods Amazon Company forest management area, in Silves, Amazonas. Analyzes such as: concentration of extractives, lignin amount, percentage of minerals (ash and tannin content, density, elemental analysis (CHNS-O and thermal analysis were done. It was observed that the chemical composition (lignin, holocellulose and elemental analysis (percentage of C, H, N and O of the woods have significant differences. The jatobá wood presented higher tannin content, and in the thermal analysis, was that which had the lowest mass loss.

  11. Kaempferitrin from Uncaria guianensis (Rubiaceae) and its potential as a chemical marker for the species

    Energy Technology Data Exchange (ETDEWEB)

    Valente, Ligia M.M.; Liechocki, Sally; Barboza, Rodolfo S.; Paixao, Djavan da [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Quimica], e-mail: valente@iq.ufrj.br; Bizarri, Carlos H.B.; Almeida, M. Beatriz S.; Benevides, Paulo J.C.; Siani, Antonio C. [Fundacao Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil). Inst. de Tecnologia em Farmacos; Magalhaes, Alvicler [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Quimica

    2009-07-01

    Uncaria tomentosa (Willd.) DC. and U. guianensis (Aubl.) Gmel., known as cat's claw, are large woody vines native to the Amazonian and Central American rain forests. The species contain, in different proportions, indole and oxindole alkaloids, triterpenoid glycosides, sterols and proanthocyanidins. U. tomentosa can be chemically identified by its oxindole alkaloid profile and content, whereas U. guianensis has no satisfactorily established chemical markers. This work describes, for the first time, the isolation of kaempferol-3,7-O-(a)-dirhamnoside (kaempferitrin) in Uncaria species. Screening for this compound in leaves, stems or bark of both species through TLC and HPLC-DAD-MS showed the presence of kaempferitrin only in the leaves and stems of U. guianensis, at a ratio almost thirty six times greater in the leaves than in the stems. These results reveal the selectivity of U. guianensis to produce this bioactive flavonoid glycoside, and suggest this compound as a potential chemical marker for the species.(author)

  12. Acute toxicity prediction to threatened and endangered species using Interspecies Correlation Estimation (ICE) models

    Science.gov (United States)

    Evaluating contaminant sensitivity of threatened and endangered (listed) species and protectiveness of chemical regulations often depends on toxicity data for commonly tested surrogate species. The U.S. EPA’s Internet application Web-ICE is a suite of Interspecies Correlati...

  13. Surrogate Modeling for Geometry Optimization

    DEFF Research Database (Denmark)

    Rojas Larrazabal, Marielba de la Caridad; Abraham, Yonas; Holzwarth, Natalie

    2009-01-01

    A new approach for optimizing the nuclear geometry of an atomic system is described. Instead of the original expensive objective function (energy functional), a small number of simpler surrogates is used.......A new approach for optimizing the nuclear geometry of an atomic system is described. Instead of the original expensive objective function (energy functional), a small number of simpler surrogates is used....

  14. Arbuscular mycorrhizal fungi alter above- and below-ground chemical defense expression differentially among Asclepias species

    Science.gov (United States)

    Vannette, Rachel L.; Hunter, Mark D.; Rasmann, Sergio

    2013-01-01

    Below-ground (BG) symbionts of plants can have substantial influence on plant growth and nutrition. Recent work demonstrates that mycorrhizal fungi can affect plant resistance to herbivory and the performance of above- (AG) and BG herbivores. Although these examples emerge from diverse systems, it is unclear if plant species that express similar defensive traits respond similarly to fungal colonization, but comparative work may inform this question. To examine the effects of arbuscular mycorrhizal fungi (AMF) on the expression of chemical resistance, we inoculated 8 species of Asclepias (milkweed)—which all produce toxic cardenolides—with a community of AMF. We quantified plant biomass, foliar and root cardenolide concentration and composition, and assessed evidence for a growth-defense tradeoff in the presence and absence of AMF. As expected, total foliar and root cardenolide concentration varied among milkweed species. Importantly, the effect of mycorrhizal fungi on total foliar cardenolide concentration also varied among milkweed species, with foliar cardenolides increasing or decreasing, depending on the plant species. We detected a phylogenetic signal to this variation; AMF fungi reduced foliar cardenolide concentrations to a greater extent in the clade including A. curassavica than in the clade including A. syriaca. Moreover, AMF inoculation shifted the composition of cardenolides in AG and BG plant tissues in a species-specific fashion. Mycorrhizal inoculation changed the relative distribution of cardenolides between root and shoot tissue in a species-specific fashion, but did not affect cardenolide diversity or polarity. Finally, a tradeoff between plant growth and defense in non-mycorrhizal plants was mitigated completely by AMF inoculation. Overall, we conclude that the effects of AMF inoculation on the expression of chemical resistance can vary among congeneric plant species, and ameliorate tradeoffs between growth and defense. PMID:24065971

  15. Arbuscular mycorrhizal fungi alter above- and below-ground chemical defense expression differentially among Asclepias species.

    Science.gov (United States)

    Vannette, Rachel L; Hunter, Mark D; Rasmann, Sergio

    2013-01-01

    Below-ground (BG) symbionts of plants can have substantial influence on plant growth and nutrition. Recent work demonstrates that mycorrhizal fungi can affect plant resistance to herbivory and the performance of above- (AG) and BG herbivores. Although these examples emerge from diverse systems, it is unclear if plant species that express similar defensive traits respond similarly to fungal colonization, but comparative work may inform this question. To examine the effects of arbuscular mycorrhizal fungi (AMF) on the expression of chemical resistance, we inoculated 8 species of Asclepias (milkweed)-which all produce toxic cardenolides-with a community of AMF. We quantified plant biomass, foliar and root cardenolide concentration and composition, and assessed evidence for a growth-defense tradeoff in the presence and absence of AMF. As expected, total foliar and root cardenolide concentration varied among milkweed species. Importantly, the effect of mycorrhizal fungi on total foliar cardenolide concentration also varied among milkweed species, with foliar cardenolides increasing or decreasing, depending on the plant species. We detected a phylogenetic signal to this variation; AMF fungi reduced foliar cardenolide concentrations to a greater extent in the clade including A. curassavica than in the clade including A. syriaca. Moreover, AMF inoculation shifted the composition of cardenolides in AG and BG plant tissues in a species-specific fashion. Mycorrhizal inoculation changed the relative distribution of cardenolides between root and shoot tissue in a species-specific fashion, but did not affect cardenolide diversity or polarity. Finally, a tradeoff between plant growth and defense in non-mycorrhizal plants was mitigated completely by AMF inoculation. Overall, we conclude that the effects of AMF inoculation on the expression of chemical resistance can vary among congeneric plant species, and ameliorate tradeoffs between growth and defense.

  16. Arbuscular mycorrhizal fungi alter above- and below-ground chemical defense expression differentially among Asclepias species

    Directory of Open Access Journals (Sweden)

    Rachel L Vannette

    2013-09-01

    Full Text Available Belowground symbionts of plants can have substantial influence on plant growth and nutrition. Recent work demonstrates that mycorrhizal fungi can affect plant resistance to herbivory and the performance of above and belowground herbivores. Although these examples emerge from diverse systems, it is unclear if plant species that express similar defensive traits respond similarly to fungal colonization, but comparative work may inform this question. To examine the effects of arbuscular mycorrhizal fungi (AMF on the expression of chemical resistance, we inoculated 8 species of Asclepias (milkweed--which all produce toxic cardenolides--with a community of AMF. We quantified plant biomass, foliar and root cardenolide concentration and composition, and assessed evidence for a growth-defense tradeoff in the presence and absence of AMF. As expected, total foliar and root cardenolide concentration varied among milkweed species. Importantly, the effect of mycorrhizal fungi on total foliar cardenolide concentration also varied among milkweed species, with foliar cardenolides increasing or decreasing, depending on the plant species. We detected a phylogenetic signal to this variation; AMF fungi reduced foliar cardenolide concentrations to a greater extent in the clade including A. curassavica than in the clade including A. syriaca. Moreover, AMF inoculation shifted the composition of cardenolides in above- and below-ground plant tissues in a species-specific fashion. Mycorrhizal inoculation changed the relative distribution of cardenolides between root and shoot tissue in a species-specific fashion, but did not affect cardenolide diversity or polarity. Finally, a tradeoff between plant growth and defense in non-mycorrhizal plants was mitigated completely by AMF inoculation. Overall, we conclude that the effects of AMF inoculation on the expression of chemical resistance can vary among congeneric plant species, and ameliorate tradeoffs between growth and

  17. Some inconvenient truths about biosignatures involving two chemical species on Earth-like exoplanets.

    Science.gov (United States)

    Rein, Hanno; Fujii, Yuka; Spiegel, David S

    2014-05-13

    The detection of strong thermochemical disequilibrium in the atmosphere of an extrasolar planet is thought to be a potential biosignature. In this article we present a previously unidentified kind of false positive that can mimic a disequilibrium or any other biosignature that involves two chemical species. We consider a scenario where the exoplanet hosts a moon that has its own atmosphere and neither of the atmospheres is in chemical disequilibrium. Our results show that the integrated spectrum of the planet and the moon closely resembles that of a single object in strong chemical disequilibrium. We derive a firm limit on the maximum spectral resolution that can be obtained for both directly imaged and transiting planets. The spectral resolution of even idealized space-based spectrographs that might be achievable in the next several decades is in general insufficient to break the degeneracy. Both chemical species can only be definitively confirmed in the same object if absorption features of both chemicals can be unambiguously identified and their combined depth exceeds 100%.

  18. The influence of electrohydrodynamic flow on the distribution of chemical species in positive corona

    Science.gov (United States)

    Pontiga, Francisco; Yanallah, Khelifa; Bouazza, R.; Chen, Junhong

    2015-09-01

    A numerical simulation of positive corona discharge in air, including the effect of electrohydrodynamic (EHD) motion of the gas, has been carried out. Air flow is assumed to be confined between two parallel plates, and corona discharge is produced around a thin wire, midway between the plates. Therefore, fluid dynamics equations, including electrical forces, have been solved together with the continuity equation of each neutral species. The plasma chemical model included 24 chemical reactions and ten neutral species, in addition to electrons and positive ions. The results of the simulation have shown that the influence of EHD flow on the spatial distributions of the species is quite different depending on the species. Hence, reactive species like atomic oxygen and atomic nitrogen are confined to the vicinity of the wire, and they are weakly affected by the EHD gas motion. In contrast, nitrogen oxides and ozone are efficiently dragged outside the active region of the corona discharge by the EHD flow. This work was supported by the Spanish Government Agency ``Ministerio de Ciencia e Innovación'' under Contract No. FIS2011-25161.

  19. Soil chemical factors and grassland species density in Emas National Park (central Brazil).

    Science.gov (United States)

    Amorim, P K; Batalha, M A

    2008-05-01

    Studies of grasslands on specific soil types suggest that different nutrients can limit biomass production and, hence, species composition and number. The Brazilian cerrado is the major savanna region in America and once covered about 2 million km(2), mainly in the Brazilian Central Plateau, under seasonal climate, with wet summer and dry winter. In view of the importance of soil chemical factors in the distribution of the vegetation forms within the Cerrado domain and which may influence the number of species, we analyzed some soil characteristics in three herbaceous vegetation forms -- hyperseasonal cerrado, seasonal cerrado, and wet grassland -- in Emas National Park, a core cerrado site, to investigate the relationship between number of species and soil characteristics. We collected vegetation and soil samples in these three vegetation forms and submitted the obtained data to multiple linear regression. We found out that aluminum and pH were the best predictors of species density, the former positively related to species density and the latter negatively related. Since the predictable variation in species density is important in determining areas of conservation, we can postulate that these two soil factors are indicators of high species density areas in tropical grasslands, which could be used in selecting priority sites for conservation.

  20. Reduced order surrogate modelling (ROSM) of high dimensional deterministic simulations

    Science.gov (United States)

    Mitry, Mina

    Often, computationally expensive engineering simulations can prohibit the engineering design process. As a result, designers may turn to a less computationally demanding approximate, or surrogate, model to facilitate their design process. However, owing to the the curse of dimensionality, classical surrogate models become too computationally expensive for high dimensional data. To address this limitation of classical methods, we develop linear and non-linear Reduced Order Surrogate Modelling (ROSM) techniques. Two algorithms are presented, which are based on a combination of linear/kernel principal component analysis and radial basis functions. These algorithms are applied to subsonic and transonic aerodynamic data, as well as a model for a chemical spill in a channel. The results of this thesis show that ROSM can provide a significant computational benefit over classical surrogate modelling, sometimes at the expense of a minor loss in accuracy.

  1. Concentrations and chemical species of arsenic in human urine and hair

    Energy Technology Data Exchange (ETDEWEB)

    Yamato, Naohisa (St. Marianna Univ. School of Medicine, Kawasaki (Japan))

    1988-05-01

    Because marine products are rich in arsenic, the concentration of arsenic in the human urine varies greatly with the state of ingestion of marine products. It has been revealed that inorganic arsenic is methylated in the human body to form MAA (methylarsonic acid) and DMAA (dimethylarsinic acid). It appears therefore that the arsenic present in the human urine is a mixture of the arsenic originating from marine products and the arsenic metabolized in vivo. Recent studies have shown that inorganic arsenic and methylarsenic compounds are quite different in toxicity and effect on the living body due to their difference in chemical species. Finding the chemical species of arsenic in the urine and hair of normal subjects will therefore provide valuable basal data for the biological monitoring of arsenic exposure and for toxicological studies of arsenic.

  2. Important sources and chemical species of ambient fine particles related to adverse health effects

    Science.gov (United States)

    Heo, J.

    2017-12-01

    Although many epidemiological studies have reported that exposure to ambient fine particulate matter (PM2.5) has been linked to increases in mortality and mobidity health outcomes, the key question of which chemical species and sources of PM2.5 are most harmful to public health remains unanswered in the air pollution research area. This study was designed to address the key question with evaluating the risks of exposure to chemical species and source-specific PM2.5 mass on morbidity. Hourly measurements of PM2.5 mass and its major chemical species, including organic carbon, elemental carbon, ions, and trace elements, were observed from January 1 to December 31, 2013 at four of the PM2.5 supersites in urban environments in Korea and the reuslts were used in a positive matrix factorization to estimate source contributions to PM2.5 mass. Nine sources, including secondary sulfate, secondary nitrate, mobile, biomass burning, roadway emission, industry, oil combustion, soil, and aged sea salt, were identified and secondary inorganic aerosol factors (i.e. secondary sulfalte, and secondary nitrate) were the dominant sources contributing to 40% of the total PM2.5 mass in the study region. In order to evaluate the risks of exposure to chemical species and sources of PM2.5 on morbidity, emergency room visits for cardivascular disease and respiratory disease were considered. Hourly health outcomes were compared with hourly measurments of the PM2.5 chemical species and sources using a poission generalized linear model incorporating natural splines, as well as time-stratified case-crossover design. The PM2.5 mass and speveral chemical components, such as organic carbon, elemetal carbon, zinc, and potassium, were strongly associated with morbidity. Source-apporitionmened PM2.5 mass derived from biomass burning, and mobile sources, was significantly associated with cardiovascular and respiratory diseases. The findings represent that local combustion may be particularly important

  3. Tree species traits influence soil physical, chemical, and biological properties in high elevation forests.

    Directory of Open Access Journals (Sweden)

    Edward Ayres

    Full Text Available BACKGROUND: Previous studies have shown that plants often have species-specific effects on soil properties. In high elevation forests in the Southern Rocky Mountains, North America, areas that are dominated by a single tree species are often adjacent to areas dominated by another tree species. Here, we assessed soil properties beneath adjacent stands of trembling aspen, lodgepole pine, and Engelmann spruce, which are dominant tree species in this region and are distributed widely in North America. We hypothesized that soil properties would differ among stands dominated by different tree species and expected that aspen stands would have higher soil temperatures due to their open structure, which, combined with higher quality litter, would result in increased soil respiration rates, nitrogen availability, and microbial biomass, and differences in soil faunal community composition. METHODOLOGY/PRINCIPAL FINDINGS: We assessed soil physical, chemical, and biological properties at four sites where stands of aspen, pine, and spruce occurred in close proximity to one-another in the San Juan Mountains, Colorado. Leaf litter quality differed among the tree species, with the highest nitrogen (N concentration and lowest lignin:N in aspen litter. Nitrogen concentration was similar in pine and spruce litter, but lignin:N was highest in pine litter. Soil temperature and moisture were highest in aspen stands, which, in combination with higher litter quality, probably contributed to faster soil respiration rates from stands of aspen. Soil carbon and N content, ammonium concentration, and microbial biomass did not differ among tree species, but nitrate concentration was highest in aspen soil and lowest in spruce soil. In addition, soil fungal, bacterial, and nematode community composition and rotifer, collembolan, and mesostigmatid mite abundance differed among the tree species, while the total abundance of nematodes, tardigrades, oribatid mites, and prostigmatid

  4. High-performance metabolic profiling of plasma from seven mammalian species for simultaneous environmental chemical surveillance and bioeffect monitoring.

    Science.gov (United States)

    Park, Youngja H; Lee, Kichun; Soltow, Quinlyn A; Strobel, Frederick H; Brigham, Kenneth L; Parker, Richard E; Wilson, Mark E; Sutliff, Roy L; Mansfield, Keith G; Wachtman, Lynn M; Ziegler, Thomas R; Jones, Dean P

    2012-05-16

    High-performance metabolic profiling (HPMP) by Fourier-transform mass spectrometry coupled to liquid chromatography gives relative quantification of thousands of chemicals in biologic samples but has had little development for use in toxicology research. In principle, the approach could be useful to detect complex metabolic response patterns to toxicologic exposures and to detect unusual abundances or patterns of potentially toxic chemicals. As an initial study to develop these possible uses, we applied HPMP and bioinformatics analysis to plasma of humans, rhesus macaques, marmosets, pigs, sheep, rats and mice to determine: (1) whether more chemicals are detected in humans living in a less controlled environment than captive species and (2) whether a subset of plasma chemicals with similar inter-species and intra-species variation could be identified for use in comparative toxicology. Results show that the number of chemicals detected was similar in humans (3221) and other species (range 2537-3373). Metabolite patterns were most similar within species and separated samples according to family and order. A total of 1485 chemicals were common to all species; 37% of these matched chemicals in human metabolomic databases and included chemicals in 137 out of 146 human metabolic pathways. Probability-based modularity clustering separated 644 chemicals, including many endogenous metabolites, with inter-species variation similar to intra-species variation. The remaining chemicals had greater inter-species variation and included environmental chemicals as well as GSH and methionine. Together, the data suggest that HPMP provides a platform that can be useful within human populations and controlled animal studies to simultaneously evaluate environmental exposures and biological responses to such exposures. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  5. Use of chemical elements of 1A family by tropical tree species

    International Nuclear Information System (INIS)

    Carmo, Andrius M.J.; Paiva, Jose Daniel S. de; Magalhaes, Marcelo R.L. de; Franca, Elvis J. de; Hazin, Clovis A.; Bacchi, Marcio A.; Fernandes, Elisabete A.N.

    2013-01-01

    This study aims to evaluate the distribution of K, Rb and Cs in leaves of trees of the Atlantic Forest through studies of correlation between the chemical elements. For this, we used the Instrumental Neutron Activation Analysis for the quantification of the chemical elements. The concentration ranges found were 6700-24000 mg / kg for K, 16 to 72mg / kg for Rb and 0.08 to 0,92mg / kg for Cs. As Rb has chemical similarity to K, is easily absorbed by plants, leading to a high value (0.9) of the Pearson correlation. For the correlation between K and Cs, no significant values were detected except for some species of the Myrtaceae family. However, average correlations (0.6 < r <0.8) between Rb-Cs were obtained for seven plant species of different families. The absence of a specific pattern using of K, Rb and Cs by plants showed great complexity in the distribution of chemical elements in the ecosystem

  6. Steam Gasification of Sawdust Biochar Influenced by Chemical Speciation of Alkali and Alkaline Earth Metallic Species

    Directory of Open Access Journals (Sweden)

    Dongdong Feng

    2018-01-01

    Full Text Available The effect of chemical speciation (H2O/NH4Ac/HCl-soluble and insoluble of alkali and alkaline earth metallic species on the steam gasification of sawdust biochar was investigated in a lab-scale, fixed-bed reactor, with the method of chemical fractionation analysis. The changes in biochar structures and the evolution of biochar reactivity are discussed, with a focus on the contributions of the chemical speciation of alkali and alkaline earth metallic species (AAEMs on the steam gasification of biochar. The results indicate that H2O/NH4Ac/HCl-soluble AAEMs have a significant effect on biochar gasification rates. The release of K occurs mainly in the form of inorganic salts and hydrated ions, while that of Ca occurs mainly as organic ones. The sp3-rich or sp2-sp3 structures and different chemical-speciation AAEMs function together as the preferred active sites during steam gasification. H2O/HCl-soluble AAEMs could promote the transformation of biochar surface functional groups, from ether/alkene C-O-C to carboxylate COO− in biochar, while they may both be improved by NH4Ac-soluble AAEMs. H2O-soluble AAEMs play a crucial catalytic role in biochar reactivity. The effect of NH4Ac-soluble AAEMs is mainly concentrated in the high-conversion stage (biochar conversion >30%, while that of HCl-soluble AAEMs is reflected in the whole activity-testing stage.

  7. Novel chemical species of Santilli’s magnegas in hadronic chemistry

    International Nuclear Information System (INIS)

    Zodape, Sangesh P.

    2015-01-01

    In this paper we have reviewed the novel chemical species, the magnecules, synthesized by Santilli that comprises of individual atoms, radicals and ordinary molecules bonded through the magnetic attractive forces originating out of toroidal polarization of the orbitals of atomic electrons under strong magnetic fields. The main focus of this paper is to review the fabulous applications of Santill’s magnegas. The novel magnecular species of hydrogen and oxygen find their place in fuel industry especially in fuel cells with the increase in its power, efficiency and total output. In this account we have also considered the flame temperature report of the new magnecular species of gases. We emphasize the importance of this new field

  8. Novel chemical species of Santilli’s magnegas in hadronic chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Zodape, Sangesh P. [Department of Chemistry, Visvesvaraya National Institute of Technology, Nagpur – 440 010, India E-mail: sangesh02@gmail.com (India)

    2015-03-10

    In this paper we have reviewed the novel chemical species, the magnecules, synthesized by Santilli that comprises of individual atoms, radicals and ordinary molecules bonded through the magnetic attractive forces originating out of toroidal polarization of the orbitals of atomic electrons under strong magnetic fields. The main focus of this paper is to review the fabulous applications of Santill’s magnegas. The novel magnecular species of hydrogen and oxygen find their place in fuel industry especially in fuel cells with the increase in its power, efficiency and total output. In this account we have also considered the flame temperature report of the new magnecular species of gases. We emphasize the importance of this new field.

  9. Chemical constituents and biological activities of species of Justicia: a review

    Directory of Open Access Journals (Sweden)

    Geone M. Corrêa

    2012-02-01

    Full Text Available The Acanthaceae family is an important source of therapeutic drugs, and the ethnopharmacological knowledge of this family requires urgent documentation as several of its species are near extinction. Justicia is the largest genus of Acanthaceae, with approximately 600 species. The present work provides a review addressing the chemistry and pharmacology of the genus Justicia. In addition, the biological activities of compounds isolated from the genus are also covered. The chemical and pharmacological information in the present work may inspire new biomedical applications for the species of Justicia, considering atom economy, the synthesis of environmentally benign products without producing toxic by-products, the use of renewable sources of raw materials, and the search for processes with maximal efficiency of energy.

  10. Chemical composition and digestibility of some browse plant species collected from Algerian arid rangelands

    Energy Technology Data Exchange (ETDEWEB)

    Boufennara, S.; Lopez, S.; Boussebouna, H.; Bodas, R.; Bouazza, L.

    2012-11-01

    Many wild browse and bush species are undervalued mainly because of insufficient knowledge about their potential feeding value. The objective was to evaluate some nutritional attributes of various Algerian browse and shub species (Atriplex halimus, Artemisia campestris, Artemisia herba-alba, Astragalus gombiformis, Calobota saharae, Retama raetam, Stipagrostis pungens, Lygeum spartum and Stipa tenacissima). Chemical composition, phenols and tannins concentration, in vitro digestibility, in vitro gas production kinetics and in vitro bio-assay for assessment of tannins using buffered rumen fluid, and in situ disappearence of the edible parts of the plants (leaves, thin twigs and flowers) were determined. In general, protein content in dicotyledon species was always greater than in monocotyledon grasses, these showing higher neutral and acid detergent fibre and lower lignin contents than dicots. The tannin concentrations varied considerably between species, but in general the plants investigated in this study had low tannin contents (except for Artemisia spp. and S. tenacissima). Monocots showed lower in vitro and in situ digestibilities, fermentation rate, cumulative gas production and extent of degradation than dicot species. The plants were clustered by principal components analysis in two groups: poor-quality grasses and the most digestible dicot species. Chemical composition (neutral detergent fibre and protein) and digestibility were the main influential variables determining the ranking. In conclusion, A. halimus, A. campestris, A. herba-alba and A. gombiformis can be considered of greater nutritional value than the highly fibrous and low digestible grasses (S. pungens, L. spartum and S. tenacissima) that should be considered emergency roughages. (Author) 46 refs.

  11. Disinfection byproduct regulatory compliance surrogates and bromide-associated risk.

    Science.gov (United States)

    Kolb, Chelsea; Francis, Royce A; VanBriesen, Jeanne M

    2017-08-01

    Natural and anthropogenic factors can alter bromide concentrations in drinking water sources. Increasing source water bromide concentrations increases the formation and alters the speciation of disinfection byproducts (DBPs) formed during drinking water treatment. Brominated DBPs are more toxic than their chlorinated analogs, and thus have a greater impact on human health. However, DBPs are regulated based on the mass sum of DBPs within a given class (e.g., trihalomethanes and haloacetic acids), not based on species-specific risk or extent of bromine incorporation. The regulated surrogate measures are intended to protect against not only the species they directly represent, but also against unregulated DBPs that are not routinely measured. Surrogates that do not incorporate effects of increasing bromide may not adequately capture human health risk associated with drinking water when source water bromide is elevated. The present study analyzes trihalomethanes (THMs), measured as TTHM, with varying source water bromide concentrations, and assesses its correlation with brominated THM, TTHM risk and species-specific THM concentrations and associated risk. Alternative potential surrogates are evaluated to assess their ability to capture THM risk under different source water bromide concentration conditions. The results of the present study indicate that TTHM does not adequately capture risk of the regulated species when source water bromide concentrations are elevated, and thus would also likely be an inadequate surrogate for many unregulated brominated species. Alternative surrogate measures, including THM 3 and the bromodichloromethane concentration, are more robust surrogates for species-specific THM risk at varying source water bromide concentrations. Copyright © 2017. Published by Elsevier B.V.

  12. In silico site-directed mutagenesis informs species-specific predictions of chemical susceptibility derived from the Sequence Alignment to Predict Across Species Susceptibility (SeqAPASS) tool

    Science.gov (United States)

    The Sequence Alignment to Predict Across Species Susceptibility (SeqAPASS) tool was developed to address needs for rapid, cost effective methods of species extrapolation of chemical susceptibility. Specifically, the SeqAPASS tool compares the primary sequence (Level 1), functiona...

  13. Comparison of the distribution of some thallium chemical species in mice

    International Nuclear Information System (INIS)

    Petitjean, Francoise.

    Scintigraphic images obtained after injection of radioactive thallium show a strong uptake on the kidneys but also on the intestines, which means that quantitative interpretation of the kidney images is troubled by the superposition of these organs. This study is an attempt to find a chemical form of thallium tending less to fix on the intestinal mucous membrane but keeping its affinity for the medullary zone of the kidney. Various agents forming stable complexes with the metal were investigated. Radiothallium is generally used in the chemical form of monovalent thallium chloride. However the degree of oxidation I is unsuitable for stable complex formation and therefore trivalent thallium was also used. Separation of Tl(I) and Tl(III) with ion exchange resin showed the instability of trivalent chloride at low concentration and when the solution is more than 2 hours old the trivalent thallium solutions injected are 10 -5 M. Calculation of the complex formation constants revealed the absence or formation of monovalent thallium complexes. In all monovalent thallium solutions (with or without carrier, with EDTA or HEDTA) the predominant chemical species is Tl + . In the case of trivalent thallium three solutions with carrier were used; the predominant species is TlCl 6 3- when the solution contains Cl - and EDTA and TlEDTA when Cl - , NO 3 - and EDTA are present. These solutions were injected intraveinously into mice in order to study the radiothallium distribution in the kidney and intestine by comparison with that of TlCl while the chemical species varied from one preparation to another no great difference in the radiothallium distribution was observed [fr

  14. 29Si NMR Chemical Shift Calculation for Silicate Species by Gaussian Software

    Science.gov (United States)

    Azizi, S. N.; Rostami, A. A.; Godarzian, A.

    2005-05-01

    Hartree-Fock self-consistent-field (HF-SCF) theory and the Gauge-including atomic orbital (GIAO) methods are used in the calculation of 29Si NMR chemical shifts for ABOUT 90 units of 19 compounds of various silicate species of precursors for zeolites. Calculations have been performed at geometries optimized at the AM1 semi-empirical method. The GIAO-HF-SCF calculations were carried out with using three different basis sets: 6-31G*, 6-31+G** and 6-311+G(2d,p). To demonstrate the quality of the calculations the calculated chemical shifts, δ, were compared with the corresponding experimental values for the compounds in study. The results, especially with 6-31+g** are in excellent agreement with experimental values. The calculated chemical shifts, in practical point of view, appear to be accurate enough to aid in experimental peak assignments. The difference between the experimental and calculated 29Si chemical shift values not only depends on the Qn units but also it seems that basis set effects and the level of theory is more important. For the series of molecules studied here, the standard deviations and mean absolute errors for 29Si chemical shifts relative to TMS determined using Hartree--Fock 6-31+G** basis is nearly in all cases smaller than the errors for shifts determined using HF/6-311+G(2d,p).

  15. Differential Sharing of Chemical Cues by Social Parasites Versus Social Mutualists in a Three-Species Symbiosis.

    Science.gov (United States)

    Emery, Virginia J; Tsutsui, Neil D

    2016-04-01

    Chemical recognition systems are crucial for maintaining the unity of social insect colonies. It has been proposed that colonies form a common chemical signature, called the gestalt odor, which is used to distinguish colony members and non-members. This chemical integration is achieved actively through social interactions such as trophallaxis and allogrooming, or passively such as through exposure to common nest material. When colonies are infiltrated by social parasites, the intruders often use some form of chemical mimicry. However, it is not always clear how this chemical mimicry is accomplished. Here, we used a three-species nesting symbiosis to test the differences in chemical integration of mutualistic (parabiotic) and parasitic ant species. We found that the parasite (Solenopsis picea) obtains chemical cues from both of the two parabiotic host ant species. However, the two parabiotic species (Crematogaster levior and Camponotus femoratus) maintain species-specific cues, and do not acquire compounds from the other species. Our findings suggest that there is a fundamental difference in how social mutualists and social parasites use chemicals to integrate themselves into colonies.

  16. A Review of Botany and Pharmacological Effect and Chemical Composition of Echinophora Species Growing in Iran.

    Science.gov (United States)

    Hosseini, Zohreh; Lorigooini, Zahra; Rafieian-Kopaei, Mahmoud; Shirmardi, Hamzeh Ali; Solati, Kamal

    2017-01-01

    This review was conducted to investigate the botany, phytochemistry, and pharmacological properties of Echinophora species. The information of this review was obtained by searching for keywords Apiaceae , Echinophora , pharmacological effects, and traditional and modern medicine in scientific articles and books published in search engines Scopus, Google Scholar, Science Direct, PubMed, and Web of Science. The traditional uses of Echinophora and the existence of valuable phytochemicals in the plant have led to isolation and drug discovery of natural medicines such as antibiotic, analgesics, and anticancer drugs, and the beneficial effects of these plants can widely be used in healthcare. Echinophora species are medicinal and aromatic plants that are belong to Apiaceae family. This genus have four species in Iran. The botany, geographical distribution, traditional and pharmacological effects of Echinophora genus were described. Also, the major chemical constituents of the essential oil and extract of different species of Echinophora that have been reported. Overall, the existence of valuable phytochemicals purpose Echinophora species as novel candidate to isolation and drug discovery of natural medicines such as antibiotic, analgesics, and anticancer drugs.

  17. Antimicrobial Activity and Chemical Composition of Essential Oils from Verbenaceae Species Growing in South America

    Directory of Open Access Journals (Sweden)

    Cristina M. Pérez Zamora

    2018-03-01

    Full Text Available The Verbenaceae family includes 2600 species grouped into 100 genera with a pantropical distribution. Many of them are important elements of the floras of warm-temperature and tropical regions of America. This family is known in folk medicine, and its species are used as digestive, carminative, antipyretic, antitussive, antiseptic, and healing agents. This review aims to collect information about the essential oils from the most reported species of the Verbenaceae family growing in South America, focusing on their chemical composition, antimicrobial activity, and synergism with commercial antimicrobials. The information gathered comprises the last twenty years of research within the South American region and is summarized taking into consideration the most representative species in terms of their essential oils. These species belong to Aloysia, Lantana, Lippia, Phyla, and Stachytarpheta genera, and the main essential oils they contain are monoterpenes and sesquiterpenes, such as β-caryophyllene, thymol, citral, 1,8-cineole, carvone, and limonene. These compounds have been found to possess antimicrobial activities. The synergism of these essential oils with antibiotics is being studied by several research groups. It constitutes a resource of interest for the potential use of combinations of essential oils and antibiotics in infection treatments.

  18. Phytotoxic activity and chemical composition of aqueous volatile fractions from Eucalyptus species.

    Directory of Open Access Journals (Sweden)

    Jinbiao Zhang

    Full Text Available The essential oils from four Eucalyptus species (E. spathulata, E. salubris, E. brockwayii and E. dundasii have been previously confirmed to have stronger inhibitory effects on germination and seedling growth of silverleaf nightshade (Solanum elaeagnifolium Cav.. The aqueous volatile fractions (AVFs were the water soluble volatile fractions produced together with the essential oils (water insoluble fractions during the steam distillation process. The aim of this study was to further assess the phytotoxicity of AVFs from the four Eucalyptus species and their chemical composition. The fresh leaves of the four Eucalyptus species were used for the extraction of AVFs. The AVFs were tested for their phytotoxic effects on the perennial weed, silverleaf nightshade under laboratory conditions. The chemical compositions of the AVFs were determined by gas chromatograph-mass spectrometry (GC-MS. Our results showed that the AVFs had strong inhibition on the germination and seedling growth of silverleaf nightshade. The inhibition index increased with the increasing concentrations of AVFs. The inhibitory effects of the AVFs varied between different Eucalyptus species. The AVF from E. salubris demonstrated the highest inhibitory activity on the weed tested, with complete inhibition on germination and seedling growth at a concentration of 75%. The GC-MS analysis revealed that 1,8-cineole, isopentyl isovalerate, isomenthol, pinocarvone, trans-pinocarveol, alpha-terpineol and globulol were the main compounds in the AVFs. These results indicated that all AVFs tested had differential inhibition on the germination and seedling growth of silverleaf nightshade, which could be due to the joint effects of compounds present in the AVFs as these compounds were present in different quantities and ratio between Eucalyptus species.

  19. Phytotoxic Activity and Chemical Composition of Aqueous Volatile Fractions from Eucalyptus Species

    Science.gov (United States)

    Zhang, Jinbiao; An, Min; Wu, Hanwen; Liu, De Li; Stanton, Rex

    2014-01-01

    The essential oils from four Eucalyptus species (E. spathulata, E. salubris, E. brockwayii and E. dundasii) have been previously confirmed to have stronger inhibitory effects on germination and seedling growth of silverleaf nightshade (Solanum elaeagnifolium Cav.). The aqueous volatile fractions (AVFs) were the water soluble volatile fractions produced together with the essential oils (water insoluble fractions) during the steam distillation process. The aim of this study was to further assess the phytotoxicity of AVFs from the four Eucalyptus species and their chemical composition. The fresh leaves of the four Eucalyptus species were used for the extraction of AVFs. The AVFs were tested for their phytotoxic effects on the perennial weed, silverleaf nightshade under laboratory conditions. The chemical compositions of the AVFs were determined by gas chromatograph–mass spectrometry (GC-MS). Our results showed that the AVFs had strong inhibition on the germination and seedling growth of silverleaf nightshade. The inhibition index increased with the increasing concentrations of AVFs. The inhibitory effects of the AVFs varied between different Eucalyptus species. The AVF from E. salubris demonstrated the highest inhibitory activity on the weed tested, with complete inhibition on germination and seedling growth at a concentration of 75%. The GC-MS analysis revealed that 1,8-cineole, isopentyl isovalerate, isomenthol, pinocarvone, trans-pinocarveol, alpha-terpineol and globulol were the main compounds in the AVFs. These results indicated that all AVFs tested had differential inhibition on the germination and seedling growth of silverleaf nightshade, which could be due to the joint effects of compounds present in the AVFs as these compounds were present in different quantities and ratio between Eucalyptus species. PMID:24681490

  20. Modeling non-isothermal multiphase multi-species reactive chemical transport in geologic media

    Energy Technology Data Exchange (ETDEWEB)

    Tianfu Xu; Gerard, F.; Pruess, K.; Brimhall, G.

    1997-07-01

    The assessment of mineral deposits, the analysis of hydrothermal convection systems, the performance of radioactive, urban and industrial waste disposal, the study of groundwater pollution, and the understanding of natural groundwater quality patterns all require modeling tools that can consider both the transport of dissolved species as well as their interactions with solid (or other) phases in geologic media and engineered barriers. Here, a general multi-species reactive transport formulation has been developed, which is applicable to homogeneous and/or heterogeneous reactions that can proceed either subject to local equilibrium conditions or kinetic rates under non-isothermal multiphase flow conditions. Two numerical solution methods, the direct substitution approach (DSA) and sequential iteration approach (SIA) for solving the coupled complex subsurface thermo-physical-chemical processes, are described. An efficient sequential iteration approach, which solves transport of solutes and chemical reactions sequentially and iteratively, is proposed for the current reactive chemical transport computer code development. The coupled flow (water, vapor, air and heat) and solute transport equations are also solved sequentially. The existing multiphase flow code TOUGH2 and geochemical code EQ3/6 are used to implement this SIA. The flow chart of the coupled code TOUGH2-EQ3/6, required modifications of the existing codes and additional subroutines needed are presented.

  1. Effectiveness of biological surrogates for predicting patterns of marine biodiversity: a global meta-analysis.

    Directory of Open Access Journals (Sweden)

    Camille Mellin

    Full Text Available The use of biological surrogates as proxies for biodiversity patterns is gaining popularity, particularly in marine systems where field surveys can be expensive and species richness high. Yet, uncertainty regarding their applicability remains because of inconsistency of definitions, a lack of standard methods for estimating effectiveness, and variable spatial scales considered. We present a Bayesian meta-analysis of the effectiveness of biological surrogates in marine ecosystems. Surrogate effectiveness was defined both as the proportion of surrogacy tests where predictions based on surrogates were better than random (i.e., low probability of making a Type I error; P and as the predictability of targets using surrogates (R(2. A total of 264 published surrogacy tests combined with prior probabilities elicited from eight international experts demonstrated that the habitat, spatial scale, type of surrogate and statistical method used all influenced surrogate effectiveness, at least according to either P or R(2. The type of surrogate used (higher-taxa, cross-taxa or subset taxa was the best predictor of P, with the higher-taxa surrogates outperforming all others. The marine habitat was the best predictor of R(2, with particularly low predictability in tropical reefs. Surrogate effectiveness was greatest for higher-taxa surrogates at a <10-km spatial scale, in low-complexity marine habitats such as soft bottoms, and using multivariate-based methods. Comparisons with terrestrial studies in terms of the methods used to study surrogates revealed that marine applications still ignore some problems with several widely used statistical approaches to surrogacy. Our study provides a benchmark for the reliable use of biological surrogates in marine ecosystems, and highlights directions for future development of biological surrogates in predicting biodiversity.

  2. Relations between chemical species distribution and the fluctuating activity of Vulcano (Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Martini, M.; Legittimo, P.C.

    1984-09-01

    Five years of systematic observation of the fumaroles of Vulcano have permitted the detection of some compositional trends coincident with a fluctuation in temperature. A gradual decrease of CO/sub 2/, H/sub 2/S+SO/sup 2/, HF was observed with the lowering of temperature, while HCl slightly increased. These physical-chemical characteristics of the system are not readily explained as simply produced by different stages in magma degassing, and the previous hypothesis of the insignificant influence of a brackish aquifer on the fumaroles still appears a reliable working model. R-mode factor analysis allowed the differentiated role of chemical species to be distinguished for which different genetic processes can be derived. The ratios HF/HCl and SO/sub 2//H/sub 2/S are taken as indicators of the changing activity of the system, and also the available data for Usu (Japan) and Mount St. Helens (USA) are considered.

  3. Light-Addressable Potentiometric Sensors for Quantitative Spatial Imaging of Chemical Species.

    Science.gov (United States)

    Yoshinobu, Tatsuo; Miyamoto, Ko-Ichiro; Werner, Carl Frederik; Poghossian, Arshak; Wagner, Torsten; Schöning, Michael J

    2017-06-12

    A light-addressable potentiometric sensor (LAPS) is a semiconductor-based chemical sensor, in which a measurement site on the sensing surface is defined by illumination. This light addressability can be applied to visualize the spatial distribution of pH or the concentration of a specific chemical species, with potential applications in the fields of chemistry, materials science, biology, and medicine. In this review, the features of this chemical imaging sensor technology are compared with those of other technologies. Instrumentation, principles of operation, and various measurement modes of chemical imaging sensor systems are described. The review discusses and summarizes state-of-the-art technologies, especially with regard to the spatial resolution and measurement speed; for example, a high spatial resolution in a submicron range and a readout speed in the range of several tens of thousands of pixels per second have been achieved with the LAPS. The possibility of combining this technology with microfluidic devices and other potential future developments are discussed.

  4. Plant Species Rather Than Climate Greatly Alters the Temporal Pattern of Litter Chemical Composition During Long-Term Decomposition

    Science.gov (United States)

    Li, Yongfu; Chen, Na; Harmon, Mark E.; Li, Yuan; Cao, Xiaoyan; Chappell, Mark A.; Mao, Jingdong

    2015-10-01

    A feedback between decomposition and litter chemical composition occurs with decomposition altering composition that in turn influences the decomposition rate. Elucidating the temporal pattern of chemical composition is vital to understand this feedback, but the effects of plant species and climate on chemical changes remain poorly understood, especially over multiple years. In a 10-year decomposition experiment with litter of four species (Acer saccharum, Drypetes glauca, Pinus resinosa, and Thuja plicata) from four sites that range from the arctic to tropics, we determined the abundance of 11 litter chemical constituents that were grouped into waxes, carbohydrates, lignin/tannins, and proteins/peptides using advanced 13C solid-state NMR techniques. Decomposition generally led to an enrichment of waxes and a depletion of carbohydrates, whereas the changes of other chemical constituents were inconsistent. Inconsistent convergence in chemical compositions during decomposition was observed among different litter species across a range of site conditions, whereas one litter species converged under different climate conditions. Our data clearly demonstrate that plant species rather than climate greatly alters the temporal pattern of litter chemical composition, suggesting the decomposition-chemistry feedback varies among different plant species.

  5. Vaporization of chemical species and the production of aerosols during a core debris/concrete interaction

    International Nuclear Information System (INIS)

    Butland, A.T.D.; Mignanelli, M.A.; Potter, P.E.; Smith, P.N.

    1987-01-01

    The equilibrium chemical composition within gas bubbles sparging through isothermal molten corium-concrete mixtures has been evaluated theoretically. A series of sensitivity calculations gives some insight into a number of factors which are of importance in determining the radionuclide and non-radioactive releases during core-concrete interaction. The degree of mixing or layering of the pool has turned out to be of paramount importance in determining the magnitudes of the releases. The presence of unoxidized zirconium in the melt tends to enhance the release of a number of species and the type of concrete used for the base mat can have a significant effect. The predictions can be sensitive to the thermodynamic data used in the calculations. The vaporization of various species into the gas bubbles can require large amounts of heat; the loss of this heat from the melt can have an effect on the extent of the vaporization

  6. Penicillium arizonense, a new, genome sequenced fungal species, reveals a high chemical diversity in secreted metabolites

    DEFF Research Database (Denmark)

    Grijseels, Sietske; Nielsen, Jens Christian; Randelovic, Milica

    2016-01-01

    A new soil-borne species belonging to the Penicillium section Canescentia is described, Penicillium arizonense sp. nov. (type strain CBS 141311T = IBT 12289T). The genome was sequenced and assembled into 33.7 Mb containing 12,502 predicted genes. A phylogenetic assessment based on marker genes...... confirmed the grouping of P. arizonense within section Canescentia. Compared to related species, P. arizonense proved to encode a high number of proteins involved in carbohydrate metabolism, in particular hemicellulases. Mining the genome for genes involved in secondary metabolite biosynthesis resulted...... of biosynthetic gene clusters in P. arizonense responsible for the synthesis of all detected compounds except curvulinic acid. The capacity to produce biomass degrading enzymes and the identification of a high chemical diversity in secreted bioactive secondary metabolites, offers a broad range of potential...

  7. Model analysis of the chemical conversion of exhaust species in the expanding plumes of subsonic aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Moellhoff, M.; Hendricks, J.; Lippert, E.; Petry, H. [Koeln Univ. (Germany). Inst. fuer Geophysik und Meteorologie; Sausen, R. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Oberpfaffenhofen (Germany). Inst. fuer Physik der Atmosphaere

    1997-12-31

    A box model and two different one-dimensional models are used to investigate the chemical conversion of exhaust species in the dispersing plume of a subsonic aircraft flying at cruise altitude. The effect of varying daytime of release as well as the impact of changing dispersion time is studied with special respect to the aircraft induced O{sub 3} production. Effective emission amounts for consideration in mesoscale and global models are calculated. Simulations with modified photolysis rates are performed to show the sensitivity of the photochemistry to the occurrence of cirrus clouds. (author) 8 refs.

  8. Model analysis of the chemical conversion of exhaust species in the expanding plumes of subsonic aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Moellhoff, M; Hendricks, J; Lippert, E; Petry, H [Koeln Univ. (Germany). Inst. fuer Geophysik und Meteorologie; Sausen, R [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Oberpfaffenhofen (Germany). Inst. fuer Physik der Atmosphaere

    1998-12-31

    A box model and two different one-dimensional models are used to investigate the chemical conversion of exhaust species in the dispersing plume of a subsonic aircraft flying at cruise altitude. The effect of varying daytime of release as well as the impact of changing dispersion time is studied with special respect to the aircraft induced O{sub 3} production. Effective emission amounts for consideration in mesoscale and global models are calculated. Simulations with modified photolysis rates are performed to show the sensitivity of the photochemistry to the occurrence of cirrus clouds. (author) 8 refs.

  9. Status of chemical elements in Atlantic Forest tree species near an industrial complex

    International Nuclear Information System (INIS)

    Araujo, A.L.L.; Fernandes, E.A.N.; Franca, E.J.; Bacchi, M.A.

    2008-01-01

    Environmental quality assessment studies have been conducted with tree species largely distributed in the Atlantic Forest. Leaf and soil samples were collected in the conservation unit Parque Estadual da Serra do Mar (PESM) nearby the industrial complex of Cubatao, Sao Paulo State, Brazil, and analyzed for chemical elements by instrumental neutron activation analysis. Results were compared to background values obtained in the Parque Estadual Carlos Botelho (PECB). The higher As, Fe, Hg and Zn mass fractions in the tree leaves of PESM indicated anthropogenic influence on this conservation unit. (author)

  10. The biological activities and chemical composition of Pereskia species (Cactaceae)--a review.

    Science.gov (United States)

    Pinto, Nícolas de Castro Campos; Scio, Elita

    2014-09-01

    The exploration of nature as a source of sustainable, novel bioactive substances continues to grow as natural products play a significant role in the search for new therapeutic and agricultural agents. In this context, plants of the genus Pereskia (Cactaceae) have been studied for their biological activities, and are evolving as an interesting subject in the search for new, bioactive compounds. These species are commonly used as human foodstuffs and in traditional medicine to treat a variety of diseases. This review focuses on the bioactivity and chemical composition of the genus Pereskia, and aims to stimulate further studies on the chemistry and biological potential of the genus.

  11. Comparison of the chemical compositions and nutritive values of various pumpkin (Cucurbitaceae) species and parts

    Science.gov (United States)

    Kim, Mi Young; Kim, Eun Jin; Kim, Young-Nam; Choi, Changsun

    2012-01-01

    Pumpkins have considerable variation in nutrient contents depending on the cultivation environment, species, or part. In this study, the general chemical compositions and some bioactive components, such as tocopherols, carotenoids, and β-sitosterol, were analyzed in three major species of pumpkin (Cucurbitaceae pepo, C. moschata, and C. maxima) grown in Korea and also in three parts (peel, flesh, and seed) of each pumpkin species. C. maxima had significantly more carbohydrate, protein, fat, and fiber than C. pepo or C. moschata (P pumpkin was highest in C. pepo. The major fatty acids in the seeds were palmitic, stearic, oleic, and linoleic acids. C. pepo and C. moschata seeds had significantly more γ-tocopherol than C. maxima, whose seeds had the highest β-carotene content. C. pepo seeds had significantly more β-sitosterol than the others. Nutrient compositions differed considerably among the pumpkin species and parts. These results will be useful in updating the nutrient compositions of pumpkin in the Korean food composition database. Additional analyses of various pumpkins grown in different years and in different areas of Korea are needed. PMID:22413037

  12. Penicillium arizonense, a new, genome sequenced fungal species, reveals a high chemical diversity in secreted metabolites

    Science.gov (United States)

    Grijseels, Sietske; Nielsen, Jens Christian; Randelovic, Milica; Nielsen, Jens; Nielsen, Kristian Fog; Workman, Mhairi; Frisvad, Jens Christian

    2016-01-01

    A new soil-borne species belonging to the Penicillium section Canescentia is described, Penicillium arizonense sp. nov. (type strain CBS 141311T = IBT 12289T). The genome was sequenced and assembled into 33.7 Mb containing 12,502 predicted genes. A phylogenetic assessment based on marker genes confirmed the grouping of P. arizonense within section Canescentia. Compared to related species, P. arizonense proved to encode a high number of proteins involved in carbohydrate metabolism, in particular hemicellulases. Mining the genome for genes involved in secondary metabolite biosynthesis resulted in the identification of 62 putative biosynthetic gene clusters. Extracts of P. arizonense were analysed for secondary metabolites and austalides, pyripyropenes, tryptoquivalines, fumagillin, pseurotin A, curvulinic acid and xanthoepocin were detected. A comparative analysis against known pathways enabled the proposal of biosynthetic gene clusters in P. arizonense responsible for the synthesis of all detected compounds except curvulinic acid. The capacity to produce biomass degrading enzymes and the identification of a high chemical diversity in secreted bioactive secondary metabolites, offers a broad range of potential industrial applications for the new species P. arizonense. The description and availability of the genome sequence of P. arizonense, further provides the basis for biotechnological exploitation of this species. PMID:27739446

  13. A novel technology for neutralizing acidity and attenuating toxic chemical species from acid mine drainage using cryptocrystalline magnesite tailings

    CSIR Research Space (South Africa)

    Masindi, Vhahangwele

    2016-04-01

    Full Text Available neutralize and attenuate elevated concentrations of chemical species in AMD to within prescribed legal frameworks for water use in agricultural and industrial sectors in South Africa....

  14. Chemical composition and fuel wood characteristics of fast growing tree species in India

    Science.gov (United States)

    Chauhan, S. K.; Soni, R.

    2012-04-01

    India is one of the growing economy in the world and energy is a critical input to sustain the growth of development. Country aims at security and efficiency of energy. Though fossil fuel will continue to play a dominant role in energy scenario but country is committed to global environmental well being thus stressing on environment friendly technologies. Concerns of energy security in this changing climatic situation have led to increasing support for the development of new renewable source of energy. Government though is determined to facilitate bio-energy and many projects have been established but initial after-affects more specifically on the domestic fuelwood are evident. Even the biomass power generating units are facing biomass crisis and accordingly the prices are going up. The CDM projects are supporting the viability of these units resultantly the Indian basket has a large number of biomass projects (144 out of total 506 with 28 per cent CERs). The use for fuelwood as a primary source of energy for domestic purpose by the poor people (approx. 80 per cent) and establishment of bio-energy plants may lead to deforestation to a great extent and only solution to this dilemma is to shift the wood harvest from the natural forests to energy plantations. However, there is conspicuous lack of knowledge with regards to the fuelwood characteristics of fast growing tree species for their selection for energy plantations. The calorific value of the species is important criteria for selection for fuel but it is affected by the proportions of biochemical constituents present in them. The aim of the present work was to study the biomass production, calorific value and chemical composition of different short rotation tree species. The study was done from the perspective of using the fast growing tree species for energy production at short rotation and the study concluded that short rotation tree species like Gmelina arborea, Eucalyptus tereticornis, Pongamia pinnata

  15. In vitro activity of natural and chemical products on sporulation of Eimeria species oocysts of chickens.

    Science.gov (United States)

    Gadelhaq, Sahar M; Arafa, Waleed M; Abolhadid, Shawky M

    2018-02-15

    This study was designed to investigate the ability of two herbal extracts and different chemical substances to inhibit or disrupt sporulation of Eimeria species oocysts of the chickens. The two herbal extracts were Allium sativum (garlic) and Moringa olifiera while the chemical substances included commercial disinfectants and diclazuril. Field isolates of Eimeria oocysts were propagated in chickens to obtain a continuous source of oocysts. The collected unsporulated oocysts (10 5 oocysts/5 ml) were dispensed into 5 cm Petri dish. Three replicates were used for each treatment. The treated oocysts were incubated for 48 h at 25-29 °C and 80% relative humidity. The results showed that herbal extracts, the commercial recommended dose of Dettol, TH4, Phenol, Virkon ® S, and Diclazuril 20% have no effect on the sporulation. While Sodium hypochlorite showed a significant degree of sporulation inhibition reached to 49.67%. Moreover, 70% ethanol, and 10% formalin showed 100% sporulation inhibition. It was concluded that 70% ethanol and 10% formalin are the most effective methods to inhibit Eimeria species sporulation. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Bufadienolides of Kalanchoe species: an overview of chemical structure, biological activity and prospects for pharmacological use.

    Science.gov (United States)

    Kolodziejczyk-Czepas, Joanna; Stochmal, Anna

    2017-01-01

    Toad venom is regarded as the main source of bufadienolides; however, synthesis of these substances takes also place in a variety of other animal and plant organisms, including ethnomedicinal plants of the Kalanchoe genus. Chemically, bufadienolides are a group of polyhydroxy C-24 steroids and their glycosides, containing a six-membered lactone (α-pyrone) ring at the C-17β position. From the pharmacological point of view, bufadienolides might be a promising group of steroid hormones with cardioactive properties and anticancer activity. Most of the literature concerns bufadienolides of animal origin; however, the medicinal use of these compounds remains limited by their narrow therapeutic index and the risk of development of cardiotoxic effects. On the other hand, plants such as Kalanchoe are also a source of bufadienolides. Kalanchoe pinnata (life plant, air plant, cathedral bells), Kalanchoe daigremontiana (mother of thousands) and other Kalanchoe species are valuable herbs in traditional medicine of Asia and Africa. The present review focuses on the available data on chemical structures of 31 compounds, biological properties and prospects for therapeutic use of bufadienolides from Kalanchoe species. Furthermore, it presents some new investigational trends in research on curative uses of these substances.

  17. Vibrational Spectroscopy of Chemical Species in Silicon and Silicon-Rich Nitride Thin Films

    Directory of Open Access Journals (Sweden)

    Kirill O. Bugaev

    2012-01-01

    Full Text Available Vibrational properties of hydrogenated silicon-rich nitride (SiN:H of various stoichiometry (0.6≤≤1.3 and hydrogenated amorphous silicon (a-Si:H films were studied using Raman spectroscopy and Fourier transform infrared spectroscopy. Furnace annealing during 5 hours in Ar ambient at 1130∘C and pulse laser annealing were applied to modify the structure of films. Surprisingly, after annealing with such high-thermal budget, according to the FTIR data, the nearly stoichiometric silicon nitride film contains hydrogen in the form of Si–H bonds. From analysis of the FTIR data of the Si–N bond vibrations, one can conclude that silicon nitride is partly crystallized. According to the Raman data a-Si:H films with hydrogen concentration 15% and lower contain mainly Si–H chemical species, and films with hydrogen concentration 30–35% contain mainly Si–H2 chemical species. Nanosecond pulse laser treatments lead to crystallization of the films and its dehydrogenization.

  18. Psychosocial aspects of surrogate motherhood.

    Science.gov (United States)

    van den Akker, Olga B A

    2007-01-01

    This review addresses the psychosocial research carried out on surrogacy triads (surrogate mothers, commissioning mothers and offspring) and shows that research has focused on a number of specific issues: attachment and disclosure to surrogate offspring; experiences, characteristics and motivations of surrogate mothers; and changes in profiles of the commissioning/intended mothers. Virtually all studies have used highly selected samples making generalizations difficult. There have been a notable lack of theory, no interventions and only a handful of longitudinal studies or studies comparing different populations. Few studies have specifically questioned the meaning of and need for a family or the influence and impact that professionals, treatment availability and financial factors have on the choices made for surrogate and intended mothers. Societal attitudes have changed somewhat; however, according to public opinion, women giving up babies still fall outside the acceptable remit. Surrogate and intended mothers appear to reconcile their unusual choice through a process of cognitive restructuring, and the success or failure of this cognitive appraisal affects people's willingness to be open and honest about their choices. Normal population surveys, on the contrary, are less accepting of third party reproduction; they have no personal need to reconsider and hence maintain their original normative cognitively consonant state.

  19. Licensing Surrogate Decision-Makers.

    Science.gov (United States)

    Rosoff, Philip M

    2017-06-01

    As medical technology continues to improve, more people will live longer lives with multiple chronic illnesses with increasing cumulative debilitation, including cognitive dysfunction. Combined with the aging of society in most developed countries, an ever-growing number of patients will require surrogate decision-makers. While advance care planning by patients still capable of expressing their preferences about medical interventions and end-of-life care can improve the quality and accuracy of surrogate decisions, this is often not the case, not infrequently leading to demands for ineffective, inappropriate and prolonged interventions. In 1980 LaFollette called for the licensing of prospective parents, basing his argument on the harm they can do to vulnerable people (children). In this paper, I apply his arguments to surrogate decision-makers for cognitively incapacitated patients, rhetorically suggesting that we require potential surrogates to qualify for this position by demonstrating their ability to make reasonable and rational decisions for others. I employ this theoretical approach to argue that the loose criteria by which we authorize surrogates' generally unchallenged power should be reconsidered.

  20. The spatial and temporal distribution of chemical species in Padaviya Reservoir, Sri Lanka.

    Science.gov (United States)

    Koliyabandara, S. M. P. A.; Siriwardhana, C.; Cooray, P. L. A. T.; Liyanage, S. S.

    2017-12-01

    Water is one of the most important assets for human life. Eutrophication and pollution are some of the major threats to many freshwater bodies. There are thousands of reservoirs exist in Sri Lanka; however, only a handful of them has been thoroughly monitored and studied. The main objective of this study is to investigate the temporal and spatial distribution of chemical species in Padaviya reservoir which is shallow man-made irrigation reservoir (8°49'30.6" N and 80°46'2.05"E) located in Sri Lanka constructed around 300 BC. The average depth is 8 m and 4 m in wet and dry seasons respectively. It has a catchment area of 270 km2. Water sampling was done at bi-monthly intervals for a period of one year staring from January 2016. Chemical analyses were conducted according to standard protocols. The maximum temperature difference between the surface and bottom waters of the reservoir was 2 °C throughout the year. The surface and bottom water conductivity varied between 175 ± 2.3 to 250 ± 3.0 μS cm-1 and 475 ± 3.7 to 600 ± 4.5 μScm-1 respectively. The average pH of surface and bottom waters varied between 8.5 ± 0.1 to 7.8 ± 0.2 and 7.2 ± 0.02 to 6.8 ± 0.2 respectively. The dissolved oxygen concentration showed a clinograde type distribution throughout the year where the surface waters were well oxygenated (DO ≈ 7.5 ppm) and the bottom waters were anoxic (DO ≈ 0.15 ppm). Ammonia concentration increased with the depth from surface concentration of 150 ± 50 to 300 ± 25 ppb at the bottom. Nitrite distribution was similar to ammonia and the surface concentration was 100 ± 25ppb throughtout the year and at the bottom it varied between 300 ± 30 to 4500 ± 30 ppb. Water soluble phosphate distribution was also similar to ammonia. The surface concentration was 200 ± 20 ppb throughtout the year and varied from 100 ± 20 to 2000 ±20 ppb at the bottom. Nitrate distribution was inverse of the ammonia. The surface concentration was 500 ± 30 to 900 ± 30 ppb

  1. Chemical composition and antibacterial activities of seven Eucalyptus species essential oils leaves.

    Science.gov (United States)

    Sebei, Khaled; Sakouhi, Fawzi; Herchi, Wahid; Khouja, Mohamed Larbi; Boukhchina, Sadok

    2015-01-19

    In this paper, we have studied the essential oils chemical composition of the leaves of seven Eucalyptus species developed in Tunisia. Eucalyptus leaves were picked from trees growing in different arboretums in Tunisia. Choucha and Mrifeg arboretums located in Sedjnene, region of Bizerte (Choucha: E. maideni, E. astrengens et E. cinerea; Mrifeg : E. leucoxylon), Korbous arboretums located in the region of Nabeul, North East Tunisia with sub-humid bioclimate, (E. lehmani), Souiniet-Ain Drahem arboretum located in region of Jendouba (E. sideroxylon, E. bicostata). Essential oils were individually tested against a large panel of microorganisms including Staphylococcus aureus (ATCC 6539), Escherichia coli (ATCC 25922), Enterococcus faecalis (ATCC29212), Listeria ivanovii (RBL 30), Bacillus cereus (ATCC11778). The yield of essential oils ranged from 1.2% to 3% (w/w) for the different Eucalyptus species. All essential oils contain α-pinene, 1,8-cineol and pinocarveol-trans for all Eucalyptus species studied. The 1,8-cineol was the major compound in all species (49.07 to 83.59%). Diameter of inhibition zone of essential oils of Eucalyptus species varied from 10 to 29 mm. The largest zone of inhibition was obtained for Bacillus cereus (E. astrengens) and the lowest for Staphylococcus aureus (E. cinerea). The essential oils from E. maideni, E. astrengens, E. cinerea (arboretum of Bizerte), E. bicostata (arboretum of Aindraham) showed the highest antibacterial activity against Listeria ivanovii and Bacillus cereus. The major constituents of Eucalyptus leaves essential oils are 1,8-cineol (49.07 to 83.59%) and α-pinene (1.27 to 26.35%). The essential oils from E. maideni, E. astrengens, E. cinerea, E. bicostata showed the highest antibacterial activity against Listeria ivanovii and Bacillus cereus, they may have potential applications in food and pharmaceutical products.

  2. The effect of elevated CO2 on the chemical composition and construction costs of leaves of 27 C-3 species

    NARCIS (Netherlands)

    Poorter, H; VanBerkel, Y; Baxter, R; DenHertog, J; Dijkstra, P; Gifford, RM; Griffin, KL; Roumet, C; Roy, J

    We determined the proximate chemical composition as well as the construction costs of leaves of 27 species, grown at ambient and at a twice-ambient partial pressure of atmospheric CO2, These species comprised wild and agricultural herbaceous plants as well as tree seedlings, Both average responses

  3. The effect of elevated CO2 on the chemical composition and construction costs of leaves of 27 C3 species

    NARCIS (Netherlands)

    Poorter, H.; Berkel, Y. van; Baxter, B.; Hertog, J. den; Dijkstra, P.; Gifford, R.M.; Griffin, K.L.; Roumet, C.; Roy, J.; Wong, S.C.

    1997-01-01

    We determined the proximate chemical composition as well as the construction costs of leaves of 27 species, grown at ambient and at a twice-ambient partial pressure of atmospheric CO₂. These species comprised wild and agricultural herbaceous plants as well as tree seedlings. Both average

  4. Preparation of Ti species coating hydrotalcite by chemical vapor deposition for photodegradation of azo dye.

    Science.gov (United States)

    Xiao, Gaofei; Zeng, HongYan; Xu, Sheng; Chen, ChaoRong; Zhao, Quan; Liu, XiaoJun

    2017-10-01

    TiO 2 in anatase crystal phase is a very effective catalyst in the photocatalytic oxidation of organic compounds in water. To improve its photocatalytic activity, the Ti-coating MgAl hydrotalcite (Ti-MgAl-LDH) was prepared by chemical vapor deposition (CVD) method. Response surface method (RSM) was employed to evaluate the effect of Ti species coating parameters on the photocatalytic activity, which was found to be affected by the furnace temperature, N 2 flow rate and influx time of precursor gas. Application of RSM successfully increased the photocatalytic efficiency of the Ti-MgAl-LDH in methylene blue photodegradation under UV irradiation, leading to improved economy of the process. According to the results from X-ray diffraction, scanning electron microscopy, Brunner-Emmet-Teller and Barrett-Joyner-Hallender, thermogravimetric and differential thermal analysis, UV-vis diffuse reflectance spectra analyses, the Ti species (TiO 2 or/and Ti 4+ ) were successfully coated on the MgAl-LDH matrix. The Ti species on the surface of the Ti-MgAl-LDH lead to a higher photocatalytic performance than commercial TiO 2 -P25. The results suggested that CVD method provided a new approach for the industrial preparation of Ti-coating MgAl-LDH material with good photocatalytic performances. Copyright © 2017. Published by Elsevier B.V.

  5. Organic Redox Species in Aqueous Flow Batteries: Redox Potentials, Chemical Stability and Solubility

    Science.gov (United States)

    Wedege, Kristina; Dražević, Emil; Konya, Denes; Bentien, Anders

    2016-01-01

    Organic molecules are currently investigated as redox species for aqueous low-cost redox flow batteries (RFBs). The envisioned features of using organic redox species are low cost and increased flexibility with respect to tailoring redox potential and solubility from molecular engineering of side groups on the organic redox-active species. In this paper 33, mainly quinone-based, compounds are studied experimentially in terms of pH dependent redox potential, solubility and stability, combined with single cell battery RFB tests on selected redox pairs. Data shows that both the solubility and redox potential are determined by the position of the side groups and only to a small extent by the number of side groups. Additionally, the chemical stability and possible degradation mechanisms leading to capacity loss over time are discussed. The main challenge for the development of all-organic RFBs is to identify a redox pair for the positive side with sufficiently high stability and redox potential that enables battery cell potentials above 1 V. PMID:27966605

  6. Organic Redox Species in Aqueous Flow Batteries: Redox Potentials, Chemical Stability and Solubility

    Science.gov (United States)

    Wedege, Kristina; Dražević, Emil; Konya, Denes; Bentien, Anders

    2016-12-01

    Organic molecules are currently investigated as redox species for aqueous low-cost redox flow batteries (RFBs). The envisioned features of using organic redox species are low cost and increased flexibility with respect to tailoring redox potential and solubility from molecular engineering of side groups on the organic redox-active species. In this paper 33, mainly quinone-based, compounds are studied experimentially in terms of pH dependent redox potential, solubility and stability, combined with single cell battery RFB tests on selected redox pairs. Data shows that both the solubility and redox potential are determined by the position of the side groups and only to a small extent by the number of side groups. Additionally, the chemical stability and possible degradation mechanisms leading to capacity loss over time are discussed. The main challenge for the development of all-organic RFBs is to identify a redox pair for the positive side with sufficiently high stability and redox potential that enables battery cell potentials above 1 V.

  7. Chemical and mechanical changes during leaf expansion of four woody species of dry Restinga woodland.

    Science.gov (United States)

    Schlindwein, C C D; Fett-Neto, A G; Dillenburg, L R

    2006-07-01

    Young leaves are preferential targets for herbivores, and plants have developed different strategies to protect them. This study aimed to evaluate different leaf attributes of presumed relevance in protection against herbivory in four woody species (Erythroxylum argentinum, Lithrea brasiliensis, Myrciaria cuspidata, and Myrsine umbellata), growing in a dry restinga woodland in southern Brazil. Evaluation of leaf parameters was made through single-point sampling of leaves (leaf mass per area and leaf contents of nitrogen, carbon, and pigments) at three developmental stages and through time-course sampling of expanding leaves (area and strength). Leaves of M. umbellata showed the highest leaf mass per area (LMA), the largest area, and the longest expansion period. On the other extreme, Myrc. cuspidata had the smallest LMA and leaf size, and the shortest expansion period. Similarly to L. brasiliensis, it displayed red young leaves. None of the species showed delayed-greening, which might be related to the high-irradiance growth conditions. Nitrogen contents reduced with leaf maturity and reached the highest values in the young leaves of E. argentinum and Myrc. cuspidata and the lowest in M. umbellata. Each species seems to present a different set of protective attributes during leaf expansion. Myrciaria cuspidata appears to rely mostly on chemical defences to protect its soft leaves, and anthocyanins might play this role at leaf youth, while M. umbellata seems to invest more on mechanical defences, even at early stages of leaf growth, as well as on a low allocation of nitrogen to the leaves. The other species display intermediate characteristics.

  8. Spot Sampling and Exposure Surrogate Selection as Sources of Bias in Environmental Epidemiology Studies

    Science.gov (United States)

    Spot measurements of chemical biomarkers are often used as quantitative exposure surrogates in environmental epidemiology studies. These measures can be expressed a number of different ways – for example, urinary biomarkers can be expressed in units of concentration (&micr...

  9. On the stabilizing role of species diffusion in chemical enhanced oil recovery

    Science.gov (United States)

    Daripa, Prabir; Gin, Craig

    2015-11-01

    In this talk, the speaker will discuss a problem on the stability analysis related to the effect of species diffusion on stabilization of fingering in a Hele-Shaw model of chemical enhanced oil recovery. The formulation of the problem is motivated by a specific design principle of the immiscible interfaces in the hope that this will lead to significant stabilization of interfacial instabilities, there by improving oil recovery in the context of porous media flow. Testing the merits of this hypothesis poses some challenges which will be discussed along with some numerical results based on current formulation of this problem. Several open problems in this context will be discussed. This work is currently under progress. Supported by the grant NPRP 08-777-1-141 from the Qatar National Research Fund (a member of The Qatar Foundation).

  10. Extension of a hybrid particle-continuum method for a mixture of chemical species

    Science.gov (United States)

    Verhoff, Ashley M.; Boyd, Iain D.

    2012-11-01

    Due to the physical accuracy and numerical efficiency achieved by analyzing transitional, hypersonic flow fields with hybrid particle-continuum methods, this paper describes a Modular Particle-Continuum (MPC) method and its extension to include multiple chemical species. Considerations that are specific to a hybrid approach for simulating gas mixtures are addressed, including a discussion of the Chapman-Enskog velocity distribution function (VDF) for near-equilibrium flows, and consistent viscosity models for the individual CFD and DSMC modules of the MPC method. Representative results for a hypersonic blunt-body flow are then presented, where the flow field properties, surface properties, and computational performance are compared for simulations employing full CFD, full DSMC, and the MPC method.

  11. Assessment of local wood species used for the manufacture of cookware and the perception of chemical benefits and chemical hazards associated with their use in Kumasi, Ghana

    Directory of Open Access Journals (Sweden)

    Mensah John Kenneth

    2012-12-01

    Full Text Available Abstract Background Historical proven wood species have no reported adverse health effect associated with its past use. Different historical proven species have traditionally been used to manufacture different wooden food contact items. This study uses survey questionnaires to assess suppliers’, manufacturers’, retailers’ and consumers’ (end-users’ preferences for specific wood species, to examine the considerations that inform these preferences and to investigate the extent of awareness of the chemical benefits and chemical hazards associated with wooden food contact material use. Methods Through the combined use of a cross sectional approach and a case study design, 25 suppliers, 25 manufacturers, 25 retailers and 125 consumers (end-users of wooden food contact materials in four suburbs in Kumasi Metropolitan Area (Anloga junction, Ahinsan Bus Stop, Ahwia-Pankrono and Race Course and Ashanti Akyim Agogo in the Ashanti Akyim North District of the Ashanti Region were administered with closed ended questionnaires. The questionnaires were prepared in English, but local language, Twi, was used to translate and communicate the content of the questionnaire where necessary. Results Suppliers’, manufacturers’ and retailers’ preferences for specific wood species for most wooden cookware differed from that of consumers (end-users. But all respondent groups failed to indicate any awareness of chemical benefits or chemical hazards associated with either the choice of specific wood species for specific wooden cookware or with the general use of wooden food contact materials. The lack of appreciation of chemical benefits or hazards associated with active principles of wooden cookware led to heavy reliance of consumers (end-users on the wood density, price, attractive grain pattern and colour or on the judgement of retailers in their choice of specific species for a wooden cookware. Conclusion This study contributes some practical suggestions

  12. Chemical composition of essential oils from four Vietnamese species of piper (piperaceae).

    Science.gov (United States)

    Hieu, Le D; Thang, Tran D; Hoi, Tran M; Ogunwande, Isiaka A

    2014-01-01

    The chemical composition of essential oils from four Piper species, Piper retrofractum Vahl., P. boehmeriaefolium (Miq.) C. DC., P. sarmentosum Roxb., and P. maclurei Merr., were analysed by gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Nineteen to sixty-four compounds representing 92.0%-98.4% of the total contents were identified in the oil samples. The major constituents identified in P. retrofractum leaf oil were benzyl benzoate (14.4%), myrcene (14.4%), bicycloelemene (9.9%), bicyclogermacrene (7.0%) and β-caryophyllene (5.3%). On the other hand, the main constituents of P. boehmeriaefolium were α-copaene (28.3%), α-pinene (7.4%) and 1, 8-cineole (5.7%). P. sarmentosum showed a very different chemical profile characterized mainly by aromatic compounds and devoid of monoterpene hydrocarbons. The major constituents were benzyl benzoate (49.1%), benzyl alcohol (17.9%), 2-hydroxy-benzoic acid phenylmethyl ester (10.0%) and 2-butenyl-benzene (7.9%). The leaf of P. maclurei was characterized by higher amount of (E)-cinnamic acid (37.4%) and (E)-nerolidol (19.4%). Moreover, (Z)-9-octadecanoic acid methyl ester (28.0%), (E)-cinnamyl acetate (17.2%), phytol (12.2%) and (E)-cinnamaldehyde (8.8%) were the major compounds identified in the stem oil.

  13. Sea Cucumber Glycosides: Chemical Structures, Producing Species and Important Biological Properties.

    Science.gov (United States)

    Mondol, Muhammad Abdul Mojid; Shin, Hee Jae; Rahman, M Aminur; Islam, Mohamad Tofazzal

    2017-10-17

    Sea cucumbers belonging to echinoderm are traditionally used as tonic food in China and other Asian countries. They produce abundant biologically active triterpene glycosides. More than 300 triterpene glycosides have been isolated and characterized from various species of sea cucumbers, which are classified as holostane and nonholostane depending on the presence or absence of a specific structural unit γ(18,20)-lactone in the aglycone. Triterpene glycosides contain a carbohydrate chain up to six monosaccharide units mainly consisting of d-xylose, 3-O-methy-d-xylose, d-glucose, 3-O-methyl-d-glucose, and d-quinovose. Cytotoxicity is the common biological property of triterpene glycosides isolated from sea cucumbers. Besides cytotoxicity, triterpene glycosides also exhibit antifungal, antiviral and hemolytic activities. This review updates and summarizes our understanding on diverse chemical structures of triterpene glycosides from various species of sea cucumbers and their important biological activities. Mechanisms of action and structural-activity relationships (SARs) of sea cucumber glycosides are also discussed briefly.

  14. Anti-Inflammatory Properties and Chemical Characterization of the Essential Oils of Four Citrus Species.

    Science.gov (United States)

    Amorim, Jorge Luis; Simas, Daniel Luiz Reis; Pinheiro, Mariana Martins Gomes; Moreno, Daniela Sales Alviano; Alviano, Celuta Sales; da Silva, Antonio Jorge Ribeiro; Fernandes, Patricia Dias

    2016-01-01

    Citrus fruits have potential health-promoting properties and their essential oils have long been used in several applications. Due to biological effects described to some citrus species in this study our objectives were to analyze and compare the phytochemical composition and evaluate the anti-inflammatory effect of essential oils (EO) obtained from four different Citrus species. Mice were treated with EO obtained from C. limon, C. latifolia, C. aurantifolia or C. limonia (10 to 100 mg/kg, p.o.) and their anti-inflammatory effects were evaluated in chemical induced inflammation (formalin-induced licking response) and carrageenan-induced inflammation in the subcutaneous air pouch model. A possible antinociceptive effect was evaluated in the hot plate model. Phytochemical analyses indicated the presence of geranial, limonene, γ-terpinene and others. EOs from C. limon, C. aurantifolia and C. limonia exhibited anti-inflammatory effects by reducing cell migration, cytokine production and protein extravasation induced by carrageenan. These effects were also obtained with similar amounts of pure limonene. It was also observed that C. aurantifolia induced myelotoxicity in mice. Anti-inflammatory effect of C. limon and C. limonia is probably due to their large quantities of limonene, while the myelotoxicity observed with C. aurantifolia is most likely due to the high concentration of citral. Our results indicate that these EOs from C. limon, C. aurantifolia and C. limonia have a significant anti-inflammatory effect; however, care should be taken with C. aurantifolia.

  15. Anti-Inflammatory Properties and Chemical Characterization of the Essential Oils of Four Citrus Species.

    Directory of Open Access Journals (Sweden)

    Jorge Luis Amorim

    Full Text Available Citrus fruits have potential health-promoting properties and their essential oils have long been used in several applications. Due to biological effects described to some citrus species in this study our objectives were to analyze and compare the phytochemical composition and evaluate the anti-inflammatory effect of essential oils (EO obtained from four different Citrus species. Mice were treated with EO obtained from C. limon, C. latifolia, C. aurantifolia or C. limonia (10 to 100 mg/kg, p.o. and their anti-inflammatory effects were evaluated in chemical induced inflammation (formalin-induced licking response and carrageenan-induced inflammation in the subcutaneous air pouch model. A possible antinociceptive effect was evaluated in the hot plate model. Phytochemical analyses indicated the presence of geranial, limonene, γ-terpinene and others. EOs from C. limon, C. aurantifolia and C. limonia exhibited anti-inflammatory effects by reducing cell migration, cytokine production and protein extravasation induced by carrageenan. These effects were also obtained with similar amounts of pure limonene. It was also observed that C. aurantifolia induced myelotoxicity in mice. Anti-inflammatory effect of C. limon and C. limonia is probably due to their large quantities of limonene, while the myelotoxicity observed with C. aurantifolia is most likely due to the high concentration of citral. Our results indicate that these EOs from C. limon, C. aurantifolia and C. limonia have a significant anti-inflammatory effect; however, care should be taken with C. aurantifolia.

  16. Evaluation of Chemical Composition and Antileishmanial and Antituberculosis Activities of Essential Oils of Piper Species

    Directory of Open Access Journals (Sweden)

    Karine Zanoli Bernuci

    2016-12-01

    Full Text Available Essential oils from fresh Piperaceae leaves were obtained by hydrodistillation and analyzed by gas chromatography mass spectrometry (GC–MS, and a total of 68 components were identified. Principal components analysis results showed a chemical variability between species, with sesquiterpene compounds predominating in the majority of species analyzed. The composition of the essential oil of Piper mosenii was described for the first time. The cytotoxicity of the essential oils was evaluated in peritoneal macrophages and the oils of P. rivinoides, P. arboretum, and P. aduncum exhibited the highest values, with cytotoxic concentration at 50% (CC50 > 200 µg/mL. Both P. diospyrifolium and P. aduncum displayed activity against Leishmania amazonensis, and were more selective for the parasite than for the macrophages, with a selectivity index (SI of 2.35 and >5.52, respectively. These SI values were greater than the 1 for the standard drug pentamidine. The antileishmanial activity of the essential oils of P. diospyrifolium and P. aduncum was described for the first time. P. rivinoides, P. cernuum, and P. diospyrifolium displayed moderate activity against the Mycobacterium tuberculosis H37Rv bacillus, with a minimum inhibitory concentration (MIC of 125 µg/mL. These results are relevant and suggests their potential for therapeutic purposes. Nevertheless, further studies are required to explain the exact mechanism of action of these essential oils.

  17. Evaluation of Chemical Composition and Antileishmanial and Antituberculosis Activities of Essential Oils of Piper Species.

    Science.gov (United States)

    Bernuci, Karine Zanoli; Iwanaga, Camila Cristina; Fernandez-Andrade, Carla Maria Mariano; Lorenzetti, Fabiana Brusco; Torres-Santos, Eduardo Caio; Faiões, Viviane Dos Santos; Gonçalves, José Eduardo; do Amaral, Wanderlei; Deschamps, Cícero; Scodro, Regiane Bertin de Lima; Cardoso, Rosilene Fressatti; Baldin, Vanessa Pietrowski; Cortez, Diógenes Aparício Garcia

    2016-12-12

    Essential oils from fresh Piperaceae leaves were obtained by hydrodistillation and analyzed by gas chromatography mass spectrometry (GC-MS), and a total of 68 components were identified. Principal components analysis results showed a chemical variability between species, with sesquiterpene compounds predominating in the majority of species analyzed. The composition of the essential oil of Piper mosenii was described for the first time. The cytotoxicity of the essential oils was evaluated in peritoneal macrophages and the oils of P. rivinoides , P. arboretum , and P. aduncum exhibited the highest values, with cytotoxic concentration at 50% (CC 50 ) > 200 µg/mL. Both P. diospyrifolium and P. aduncum displayed activity against Leishmania amazonensis , and were more selective for the parasite than for the macrophages, with a selectivity index (SI) of 2.35 and >5.52, respectively. These SI values were greater than the 1 for the standard drug pentamidine. The antileishmanial activity of the essential oils of P. diospyrifolium and P. aduncum was described for the first time. P. rivinoides, P. cernuum , and P. diospyrifolium displayed moderate activity against the Mycobacterium tuberculosis H 37 Rv bacillus, with a minimum inhibitory concentration (MIC) of 125 µg/mL. These results are relevant and suggests their potential for therapeutic purposes. Nevertheless, further studies are required to explain the exact mechanism of action of these essential oils.

  18. Chemical and morphological characteristics of key tree species of the Carpathian Mountains

    International Nuclear Information System (INIS)

    Mankovska, Blanka; Godzik, Barbara; Badea, Ovidiu; Shparyk, Yuri; Moravcik, Pavel

    2004-01-01

    Concentrations of Al, B, Ca, Cu, Fe, K, Mg, Mn, N, Na, P, S and Zn in the foliage of white fir (Abies alba), Norway spruce (Picea abies) and common beech (Fagus sylvatica) from 25 sites of the Carpathian Mts. forests (Czech Republic, Poland, Romania, Slovakia and Ukraine) are discussed in a context of their limit values. S/N ratio was different from optimum in 90% of localities when compared with the European limit values. Likewise we found increase of Fe and Cu concentrations compared with their background levels in 100% of locations. Mn concentrations were increased in 76% of localities. Mn mobilization values indicate the disturbance of physiological balance leading to the change of the ratio with Fe. SEM-investigation of foliage waxes from 25 sites in the Carpathian Mts. showed, that there is a statistically significant difference in mean wax quality. Epistomatal waxes were damaged as indicated by increased development of net and amorphous waxes. The most damaged stomata in spruce needles were from Yablunitsa, Synevir and Brenna; in fir needles from Stoliky, and in beech leaves from Mala Fatra, Morske Oko and Beregomet. Spruce needles in the Carpathian Mts. had more damaged stomata than fir needles and beech leaves. Spruce seems to be the most sensitive tree species to environmental stresses including air pollution in forests of the Carpathian Mountains. Foliage surfaces of three forest tree species contained Al, Si, Ca, Fe, Mg, K, Cl, Mn, Na, Ni and Ti in all studied localities. Presence of nutrition elements (Ca, Fe, Mg, K and Mn) on foliage surface hinders opening and closing stomata and it is not physiologically usable for tree species. - Chemical composition of foliage and structure of epicuticular waxes indicated phytotoxic effects of air pollution in many forest sites of the Carpathian Mountains

  19. Evidence for chemical interference effect of an allelopathic plant on neighboring plant species: A field study.

    Directory of Open Access Journals (Sweden)

    Antonio I Arroyo

    Full Text Available Many studies have reported the phytotoxicity of allelopathic compounds under controlled conditions. However, more field studies are required to provide realistic evidences for the significance of allelopathic interference in natural communities. We conducted a 2-years field experiment in a semiarid plant community (NE Spain. Specifically, we planted juvenile individuals and sowed seeds of Salsola vermiculata L., Lygeum spartum L. and Artemisia herba-alba Asso. (three co-dominant species in the community beneath adult individuals of the allelopathic shrub A. herba-alba, and assessed the growth, vitality, seed germination and seedling survival of those target species with and without the presence of chemical interference by the incorporation of activated carbon (AC to the soil. In addition, juveniles and seeds of the same three target species were planted and sown beneath the canopy of adults of S. vermiculata (a shrub similar to A. herba-alba, but non-allelopathic and in open bare soil to evaluate whether the allelopathic activity of A. herba-alba modulates the net outcome of its interactions with neighboring plants under contrasting abiotic stress conditions. We found that vitality of A. herba-alba juveniles was enhanced beneath A. herba-alba individuals when AC was present. Furthermore, we found that the interaction outcome in A. herba-alba microsite was neutral, whereas a positive outcome was found for S. vermiculata microsite, suggesting that allelopathy may limit the potential facilitative effects of the enhanced microclimatic conditions in A. herba-alba microsite. Yet, L. spartum juveniles were facilitated in A. herba-alba microsite. The interaction outcome in A. herba-alba microsite was positive under conditions of very high abiotic stress, indicating that facilitative interactions predominated over the interference of allelopathic plants under those conditions. These results highlight that laboratory studies can overestimate the

  20. Evidence for chemical interference effect of an allelopathic plant on neighboring plant species: A field study.

    Science.gov (United States)

    Arroyo, Antonio I; Pueyo, Yolanda; Giner, M Luz; Foronda, Ana; Sanchez-Navarrete, Pedro; Saiz, Hugo; Alados, Concepción L

    2018-01-01

    Many studies have reported the phytotoxicity of allelopathic compounds under controlled conditions. However, more field studies are required to provide realistic evidences for the significance of allelopathic interference in natural communities. We conducted a 2-years field experiment in a semiarid plant community (NE Spain). Specifically, we planted juvenile individuals and sowed seeds of Salsola vermiculata L., Lygeum spartum L. and Artemisia herba-alba Asso. (three co-dominant species in the community) beneath adult individuals of the allelopathic shrub A. herba-alba, and assessed the growth, vitality, seed germination and seedling survival of those target species with and without the presence of chemical interference by the incorporation of activated carbon (AC) to the soil. In addition, juveniles and seeds of the same three target species were planted and sown beneath the canopy of adults of S. vermiculata (a shrub similar to A. herba-alba, but non-allelopathic) and in open bare soil to evaluate whether the allelopathic activity of A. herba-alba modulates the net outcome of its interactions with neighboring plants under contrasting abiotic stress conditions. We found that vitality of A. herba-alba juveniles was enhanced beneath A. herba-alba individuals when AC was present. Furthermore, we found that the interaction outcome in A. herba-alba microsite was neutral, whereas a positive outcome was found for S. vermiculata microsite, suggesting that allelopathy may limit the potential facilitative effects of the enhanced microclimatic conditions in A. herba-alba microsite. Yet, L. spartum juveniles were facilitated in A. herba-alba microsite. The interaction outcome in A. herba-alba microsite was positive under conditions of very high abiotic stress, indicating that facilitative interactions predominated over the interference of allelopathic plants under those conditions. These results highlight that laboratory studies can overestimate the significance of

  1. Effectiveness of biodiversity surrogates for conservation planning: different measures of effectiveness generate a kaleidoscope of variation.

    Directory of Open Access Journals (Sweden)

    Hedley S Grantham

    Full Text Available Conservation planners represent many aspects of biodiversity by using surrogates with spatial distributions readily observed or quantified, but tests of their effectiveness have produced varied and conflicting results. We identified four factors likely to have a strong influence on the apparent effectiveness of surrogates: (1 the choice of surrogate; (2 differences among study regions, which might be large and unquantified (3 the test method, that is, how effectiveness is quantified, and (4 the test features that the surrogates are intended to represent. Analysis of an unusually rich dataset enabled us, for the first time, to disentangle these factors and to compare their individual and interacting influences. Using two data-rich regions, we estimated effectiveness using five alternative methods: two forms of incidental representation, two forms of species accumulation index and irreplaceability correlation, to assess the performance of 'forest ecosystems' and 'environmental units' as surrogates for six groups of threatened species-the test features-mammals, birds, reptiles, frogs, plants and all of these combined. Four methods tested the effectiveness of the surrogates by selecting areas for conservation of the surrogates then estimating how effective those areas were at representing test features. One method measured the spatial match between conservation priorities for surrogates and test features. For methods that selected conservation areas, we measured effectiveness using two analytical approaches: (1 when representation targets for the surrogates were achieved (incidental representation, or (2 progressively as areas were selected (species accumulation index. We estimated the spatial correlation of conservation priorities using an index known as summed irreplaceability. In general, the effectiveness of surrogates for our taxa (mostly threatened species was low, although environmental units tended to be more effective than forest ecosystems

  2. Recent Progress in the Development of Diesel Surrogate Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Pitz, W J; Mueller, C J

    2009-12-09

    There has been much recent progress in the area of surrogate fuels for diesel. In the last few years, experiments and modeling have been performed on higher molecular weight components of relevance to diesel fuel such as n-hexadecane (n-cetane) and 2,2,4,4,6,8,8-heptamethylnonane (iso-cetane). Chemical kinetic models have been developed for all the n-alkanes up to 16 carbon atoms. Also, there has been much experimental and modeling work on lower molecular weight surrogate components such as n-decane and n-dodecane that are most relevant to jet fuel surrogates, but are also relevant to diesel surrogates where simulation of the full boiling point range is desired. For two-ring compounds, experimental work on decalin and tetralin recently has been published. For multi-component surrogate fuel mixtures, recent work on modeling of these mixtures and comparisons to real diesel fuel is reviewed. Detailed chemical kinetic models for surrogate fuels are very large in size. Significant progress also has been made in improving the mechanism reduction tools that are needed to make these large models practicable in multi-dimensional reacting flow simulations of diesel combustion. Nevertheless, major research gaps remain. In the case of iso-alkanes, there are experiments and modeling work on only one of relevance to diesel: iso-cetane. Also, the iso-alkanes in diesel are lightly branched and no detailed chemical kinetic models or experimental investigations are available for such compounds. More components are needed to fill out the iso-alkane boiling point range. For the aromatic class of compounds, there has been no new work for compounds in the boiling point range of diesel. Most of the new work has been on alkyl aromatics that are of the range C7 to C8, below the C10 to C20 range that is needed. For the chemical class of cycloalkanes, experiments and modeling on higher molecular weight components are warranted. Finally for multi-component surrogates needed to treat real

  3. Divergent chemical cues elicit seed collecting by ants in an obligate multi-species mutualism in lowland Amazonia.

    Directory of Open Access Journals (Sweden)

    Elsa Youngsteadt

    2010-12-01

    Full Text Available In lowland Amazonian rainforests, specific ants collect seeds of several plant species and cultivate them in arboreal carton nests, forming species-specific symbioses called ant-gardens (AGs. In this obligate mutualism, ants depend on the plants for nest stability and the plants depend on ant nests for substrate and nutrients. AG ants and plants are abundant, dominant members of lowland Amazonian ecosystems, but the cues ants use to recognize the seeds are poorly understood. To address the chemical basis of the ant-seed interaction, we surveyed seed chemistry in nine AG species and eight non-AG congeners. We detected seven phenolic and terpenoid volatiles common to seeds of all or most of the AG species, but a blend of the shared compounds was not attractive to the AG ant Camponotus femoratus. We also analyzed seeds of three AG species (Anthurium gracile, Codonanthe uleana, and Peperomia macrostachya using behavior-guided fractionation. At least one chromatographic fraction of each seed extract elicited retrieval behavior in C. femoratus, but the active fractions of the three plant species differed in polarity and chemical composition, indicating that shared compounds alone did not explain seed-carrying behavior. We suggest that the various AG seed species must elicit seed-carrying with different chemical cues.

  4. The physico-chemical radioiodine species in the exhaust air of a pressurized water reactor (PWR2)

    International Nuclear Information System (INIS)

    Deuber, H.

    1981-12-01

    In a German pressurized water reactor, the physico-chemical 131 I species were determined in the plant exhaust and in the individual exhausts during 6 months. These measurements aimed in particular at determining the percentage and the source of the radiologically decisive elemental 131 I released to the environment. The retention of the 131 I species by iodine filters was also investigated. 20 to 30% of the 131 I discharged with the plant exhaust consisted of elemental iodine. This was largely released with the unfiltered exhaust from the chemical laboratory hoods and from the annular compartment. (orig.) [de

  5. A surrogate fuel formulation to characterize heating and evaporation of light naphtha droplets

    KAUST Repository

    Kabil, I.

    2018-03-08

    Light naphtha (LN) is gaining interest in internal combustion (IC) engine applications due to its low refining cost and higher heating values compared to commercial gasoline. To properly describe the chemical and physical behavior of the LN fuel under IC engine conditions, a systematic procedure to develop unified physical and chemical surrogates is described. The reduced component models to describe the chemical characteristics of LN are combined with the effective thermal conductivity/effective diffusivity (ETC/ED) model to represent the accurate evaporation behavior. Three surrogate fuels consisting of three to five components are presented and their performance in heating and evaporation of a single LN droplet is compared against the conventional primary reference fuel (PRF65) surrogate which is based on chemical aspects only. Unlike the previous approaches, the new surrogates also target matching the hydrogen-to-carbon ratio and research octane number in order to accurately describe the chemical behavior of the fuel. Subsequently, the performance of the surrogates in describing spray characteristics is tested by computational simulations compared with experimental measurements. The simulations were carried out using CONVERGE CFD package. The ETC/ED model was implemented into CONVERGE using user-defined functions. The predicted spray penetration length for the developed surrogates shows good agreement with the experimental data. At engine-like conditions, the ETC/ED model predicts higher vapor mass than the infinite thermal conductivity/infinite diffusivity model, hence showing the expected trend by incorporating the realistic droplet heating process.

  6. A surrogate fuel formulation to characterize heating and evaporation of light naphtha droplets

    KAUST Repository

    Kabil, I.; Sim, J.; Badra, J.A.; Eldrainy, Y.; Abdelghaffar, W.; Mubarak Ali, M. Jaasim; Ahmed, Ahfaz; Sarathy, Mani; Im, Hong G.; Elwardani, Ahmed Elsaid

    2018-01-01

    Light naphtha (LN) is gaining interest in internal combustion (IC) engine applications due to its low refining cost and higher heating values compared to commercial gasoline. To properly describe the chemical and physical behavior of the LN fuel under IC engine conditions, a systematic procedure to develop unified physical and chemical surrogates is described. The reduced component models to describe the chemical characteristics of LN are combined with the effective thermal conductivity/effective diffusivity (ETC/ED) model to represent the accurate evaporation behavior. Three surrogate fuels consisting of three to five components are presented and their performance in heating and evaporation of a single LN droplet is compared against the conventional primary reference fuel (PRF65) surrogate which is based on chemical aspects only. Unlike the previous approaches, the new surrogates also target matching the hydrogen-to-carbon ratio and research octane number in order to accurately describe the chemical behavior of the fuel. Subsequently, the performance of the surrogates in describing spray characteristics is tested by computational simulations compared with experimental measurements. The simulations were carried out using CONVERGE CFD package. The ETC/ED model was implemented into CONVERGE using user-defined functions. The predicted spray penetration length for the developed surrogates shows good agreement with the experimental data. At engine-like conditions, the ETC/ED model predicts higher vapor mass than the infinite thermal conductivity/infinite diffusivity model, hence showing the expected trend by incorporating the realistic droplet heating process.

  7. Surrogate mothering: exploitation or empowerment?

    Science.gov (United States)

    Purdy, Laura M

    1989-01-01

    The morality of surrogate mothering is analyzed from a "consequentialist" framework which attempts to separate those consequences that invariably accompany a given act from those that accompany it only in particular circumstances. Critics of surrogacy argue that it transfers the burden and risk of pregnancy onto another woman, separates sex and reproduction, and separates reproduction and childrearing; none of these acts is necessarily wrong, either morally or for women's or society's basic interests. While surrogate mothering can be rendered immoral if women are coerced into the practice or become victims of subordinating or penalizing contracts, it has the potential to empower women and increase their status in society by providing a job that is less risky and more enjoyable than other jobs women are forced to take and by achieving greater social recognition for reproductive labor.

  8. Chemical Analysis and Biological Activity of the Essential Oils of Two Endemic Soqotri Commiphora Species

    Directory of Open Access Journals (Sweden)

    Wulf Schultze

    2010-02-01

    Full Text Available The barks of two endemic Commiphora species namely, Commiphora ornifolia (Balf.f. Gillett and Commiphora parvifolia Engl., were collected from Soqotra Island in Yemen and their essential oils were obtained by hydrodistillation. The chemical composition of both oils was investigated by GC and GC-MS. Moreover, the essential oils were evaluated for their antimicrobial activity against two Gram-positive bacteria, two Gram-negative bacteria and one yeast species by using a broth micro-dilution assay for minimum inhibitory concentrations (MIC and for their antioxidant activity by measuring the DPPH radical scavenging activity. A total of 45 constituents of C. ornifolia (85.6% and 44 constituents of C. parvifolia (87.1% were identified. The oil of C. ornifolia was characterized by a high content of oxygenated monoterpenes (56.3%, of which camphor (27.3%, α-fenchol (15.5%, fenchone (4.4% and borneol (2.9% were identified as the main components. High contents of oxygenated sesquiterpenes (36.1% and aliphatic acids (22.8% were found in C. parvifolia oil, in which caryophyllene oxide (14.2%, β-eudesmol (7.7%, bulnesol (5.7%, T-cadinol (3.7% and hexadecanoic acid (18.4% predominated. The results of the antimicrobial assay showed that both oils exhibited moderate to high antibacterial activity especially against Gram-positive bacteria. C. ornifolia oil was the most active. In addition, the DPPH-radical scavenging assay exhibited only weak antioxidant activities for both oils at the high concentration tested.

  9. Chemical variation in a dominant tree species: population divergence, selection and genetic stability across environments.

    Directory of Open Access Journals (Sweden)

    Julianne M O'Reilly-Wapstra

    Full Text Available Understanding among and within population genetic variation of ecologically important plant traits provides insight into the potential evolutionary processes affecting those traits. The strength and consistency of selection driving variability in traits would be affected by plasticity in differences among genotypes across environments (G×E. We investigated population divergence, selection and environmental plasticity of foliar plant secondary metabolites (PSMs in a dominant tree species, Eucalyptus globulus. Using two common garden trials we examined variation in PSMs at multiple genetic scales; among 12 populations covering the full geographic range of the species and among up to 60 families within populations. Significant genetic variation in the expression of many PSMs resides both among and within populations of E. globulus with moderate (e.g., sideroxylonal A h(2op = 0.24 to high (e.g., macrocarpal G h(2op = 0.48 narrow sense heritabilities and high coefficients of additive genetic variation estimated for some compounds. A comparison of Qst and Fst estimates suggest that variability in some of these traits may be due to selection. Importantly, there was no genetic by environment interaction in the expression of any of the quantitative chemical traits despite often significant site effects. These results provide evidence that natural selection has contributed to population divergence in PSMs in E. globulus, and identifies the formylated phloroglucinol compounds (particularly sideroxylonal and a dominant oil, 1,8-cineole, as candidates for traits whose genetic architecture has been shaped by divergent selection. Additionally, as the genetic differences in these PSMs that influence community phenotypes is stable across environments, the role of plant genotype in structuring communities is strengthened and these genotypic differences may be relatively stable under global environmental changes.

  10. Chemical Composition and Biological Activity of Essential Oils from Different Species of Piper from Panama.

    Science.gov (United States)

    Santana, Ana I; Vila, Roser; Cañigueral, Salvador; Gupta, Mahabir P

    2016-07-01

    The chemical composition of leaf essential oils from 11 species of Piper from Panama was analyzed by a combination GC-FID and GC-MS procedures. Six of them had sesquiterpene hydrocarbons as major constituents, three were characterized by monoterpene hydrocarbons, one by a diterpene, and one by a phenylpropanoid, dillapiole. The main components identified in each species were: cembratrienol (25.4 %) in Piper augustum; β-pinene (26.6 %) in Piper corrugatum; α-pinene (19.4 %) in Piper curtispicum; trans-β-farnesene (63.7 %) in Piper darienense; p-cymene (43.9 %) in Piper grande; dillapiole (57.7 %) in Piper hispidum; linalool (14.5 %), α-phellandrene (13.8 %), and limonene (12.2 %) in Piper jacquemontianum; β-caryophyllene (45.2 %) in Piper longispicum; linalool (16.5 %), α-phellandrene (11.8 %), limonene (11.4 %), and p-cymene (9.0 %) in Piper multiplinervium; β-selinene (19.0 %), β-elemene (16.1 %), and α-selinene (15.5 %) in Piper reticulatum; and germacrene D (19.7 %) in Piper trigonum. The essential oils of P. hispidum and P. longispicum at a concentration of 250 µg/mL showed larvicidal activity against Aedes aegypti, while the oils from P. curtispicum, P. multiplinervium, P. reticulatum, and P. trigonum were inactive (LC100 ≥ 500 µg/mL). The essential oils of P. grande, P. jacquemontianum, and P. multiplinervium showed no significant antifungal activity (MIC > 250 µg/mL) against several yeasts and filamentous fungal strains. Georg Thieme Verlag KG Stuttgart · New York.

  11. Chemical Composition, Nitrogen Fractions and Amino Acids Profile of Milk from Different Animal Species

    Directory of Open Access Journals (Sweden)

    Saima Rafiq

    2016-07-01

    Full Text Available Milk composition is an imperative aspect which influences the quality of dairy products. The objective of study was to compare the chemical composition, nitrogen fractions and amino acids profile of milk from buffalo, cow, sheep, goat, and camel. Sheep milk was found to be highest in fat (6.82%±0.04%, solid-not-fat (11.24%±0.02%, total solids (18.05%±0.05%, protein (5.15%±0.06% and casein (3.87%±0.04% contents followed by buffalo milk. Maximum whey proteins were observed in camel milk (0.80%±0.03%, buffalo (0.68%±0.02% and sheep (0.66%±0.02% milk. The non-protein-nitrogen contents varied from 0.33% to 0.62% among different milk species. The highest r-values were recorded for correlations between crude protein and casein in buffalo (r = 0.82, cow (r = 0.88, sheep (r = 0.86 and goat milk (r = 0.98. The caseins and whey proteins were also positively correlated with true proteins in all milk species. A favorable balance of branched-chain amino acids; leucine, isoleucine, and valine were found both in casein and whey proteins. Leucine content was highest in cow (108±2.3 mg/g, camel (96±2.2 mg/g and buffalo (90±2.4 mg/g milk caseins. Maximum concentrations of isoleucine, phenylalanine, and histidine were noticed in goat milk caseins. Glutamic acid and proline were dominant among non-essential amino acids. Conclusively, current exploration is important for milk processors to design nutritious and consistent quality end products.

  12. Toward a Psychology of Surrogate Decision Making.

    Science.gov (United States)

    Tunney, Richard J; Ziegler, Fenja V

    2015-11-01

    In everyday life, many of the decisions that we make are made on behalf of other people. A growing body of research suggests that we often, but not always, make different decisions on behalf of other people than the other person would choose. This is problematic in the practical case of legally designated surrogate decision makers, who may not meet the substituted judgment standard. Here, we review evidence from studies of surrogate decision making and examine the extent to which surrogate decision making accurately predicts the recipient's wishes, or if it is an incomplete or distorted application of the surrogate's own decision-making processes. We find no existing domain-general model of surrogate decision making. We propose a framework by which surrogate decision making can be assessed and a novel domain-general theory as a unifying explanatory concept for surrogate decisions. © The Author(s) 2015.

  13. Chemically engineering ligand selectivity at the free fatty acid receptor 2 based on pharmacological variation between species orthologs

    DEFF Research Database (Denmark)

    Hudson, Brian D; Christiansen, Elisabeth; Tikhonova, Irina G

    2012-01-01

    When it is difficult to develop selective ligands within a family of related G-protein-coupled receptors (GPCRs), chemically engineered receptors activated solely by synthetic ligands (RASSLs) are useful alternatives for probing receptor function. In the present work, we explored whether a RASSL...... on this receptor and demonstrates that exploitation of pharmacological variation between species orthologs is a powerful method to generate novel chemically engineered GPCRs.-Hudson, B. D., Christiansen, E., Tikhonova, I. G., Grundmann, M., Kostenis, E., Adams, D. R., Ulven, T., Milligan, G. Chemically engineering...

  14. Ethnopharmacological and Chemical Characterization of Salvia Species Used in Valencian Traditional Herbal Preparations

    Directory of Open Access Journals (Sweden)

    Vanessa Martínez-Francés

    2017-07-01

    Full Text Available In Valencia Region (Spain, some wild and cultivated sages are used for medicinal purposes. Among them, Salvia officinalis subsp. lavandulifolia (SL is widely employed and known for production of Spanish sage oil and herbal products. Nevertheless, it shares the market with S. blancoana subsp. mariolensis (SB and, to a lesser extent, with their hybrid S. x hegelmaieri (SH. The knowledge on these two species is far low and confusion between them is possible. The aim of the present paper is to improve the ethnopharmacological, morphological and chemical knowledge of these sages, and to contribute to setting up quality specifications for improving identification and distinction from other Salvia species, such as, S. officinalis subsp. officinalis, S. x auriculata and S. microphylla var. microphylla. Samples were collected in Valencia Region and surrounding mountain areas during the ethnopharmacological field work. Twenty-nine medicinal uses were reported for SL, 13 of them being also recorded for SB. Of particular interest is a homemade liquor, used as digestive and known as “salvieta,” which is mainly prepared with SB. The macro- and microscopic characters are insufficient for identification of cut, crushed or powdered material. The study of the essential oil and a HPTLC (High Performance Thin Layer Chromatography fingerprint of their extracts could help to distinguish SB from the other sages. The essential oil from dried aerial parts of SB (content: 1.8–4.5% was characterized by GC-FID (Gas Chromatography with Flame Ionization Detector and GC-MS (Gas Chromatography coupled to Mass Spectrometry showing a composition close to that currently accepted for Spanish sage essential oil in the European Pharmacopoeia, ISO (International Standard Organization and UNE (Una Norma Española standards, with 1,8-cineole (13.7–45.7% and camphor (12.1–28.6% as major constituents. HPTLC methods, based on the analysis of hydroalcoholic and dichloromethane

  15. Chemical compositions of essential oils from two Artemisia species used in Mongolian traditional medicine

    Directory of Open Access Journals (Sweden)

    Javzmaa N

    2018-02-01

    Full Text Available Essential oils of aromatic and medicinal plants generally have a diverse range of activities because they possess many active constituents that work through a several modes of action. Artemisia, the largest genus of the family Asteraceae, has a number of effects against human and plant diseases. The main purpose of the present study was to investigate chemical compositions of essential oils of two Artemisia species, Artemisia palustris L and Artemisia sericea Weber ex Stechm from the Mongolian steppe zone using gas chromatography and gas chromatography-mass spectrometry. The essential oil of A.palustris was characterized by the presence of monoterpene hydrocarbons such as  trans-β-ocimene (59.1%, cis-β-ocimene (11.6% and myrcene (7.1%, while the oil of A.sericea was dominated by the presence of three oxygenated monoterpenoids as 1,8-cineole (25.8%, borneol (22.5% and camphor (18.8% which are used for preparation of a fragrance and medicinal products.

  16. MORPHO-CHEMICAL DESCRIPTION AND ANTIMICROBIAL ACTIVITY OF DIFFERENT OCIMUM SPECIES

    Directory of Open Access Journals (Sweden)

    KAKARAPARTHI PANDU SASTRY

    2012-12-01

    Full Text Available Basil is a popular medicinal and culinary herb, and its essential oils have been used extensively for many years in food products, perfumery, dental and oral products. Basil essential oils and their principal constituents were found to exhibit antimicrobial activity against a wide range of Gram-negative and Gram-positive bacteria, yeast, and mould. The essential oils obtained from aerial parts of three different species of Ocimum comprising twenty one germplasm lines were investigated for their essential oil composition and antimicrobial activity during 2010. Essential oils from seventeen germplasm lines in Ocimum basilicum and two each in Ocimum tenuiflorum and Ocimum gratissimum were investigated for anti-microbial activity against four bacterial strains (Staphylococcus aureus, Bacillus sps., Escherichia coli and Pseudomonas aeruginosa. The morpho-chemotypes exhibited wide variability for morphological and chemical traits. Anti-bacterial activity was found to be high for Staphylococcus aureus, moderate for Escherichia coli, low for Bacillus and Pseudomonas aeruginosa was highly resistant. The essential oils of Pale Green-Broad Leaves (O. basilicum and CIM Ayu (O. gratissimum exhibited significant antibacterial activity against both S. aureus and E. coli signifying them promising for anti-bacterial activity. No relationship was observed between chemotype specificity and anti-bacterial activity, indicating that apart from major components of essential oil, minor components and other factors may be responsible for anti-microbial activities.

  17. Chemical Composition and Acetylcholinesterase Inhibitory Activity of Essential Oils from Piper Species.

    Science.gov (United States)

    Xiang, Cai-Peng; Han, Jia-Xin; Li, Xing-Cong; Li, Yun-Hui; Zhang, Yi; Chen, Lin; Qu, Yan; Hao, Chao-Yun; Li, Hai-Zhou; Yang, Chong-Ren; Zhao, San-Jun; Xu, Min

    2017-05-10

    The essential oils (EOs) derived from aromatic plants such as Piper species are considered to play a role in alleviating neuronal ailments that are associated with inhibition of acetylcholinesterase (AChE). The chemical compositions of 23 EOs prepared from 16 Piper spp. were analyzed by both gas chromatography with a flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). A total of 76 compounds were identified in the EOs from the leaves and stems of 19 samples, while 30 compounds were detected in the EOs from the fruits of four samples. Sesquiterpenes and phenylpropanoids were found to be rich in these EOs, of which asaricin, caryophyllene, caryophyllene oxide, isospathulenol, (+)-spathulenol, and β-bisabolene are the major constituents. The EOs from the leaves and stems of Piper austrosinense, P. puberulum, P. flaviflorum, P. betle, and P. hispidimervium showed strong AChE inhibitory activity with IC 50 values in the range of 1.51 to 13.9 mg/mL. A thin-layer chromatography (TLC) bioautography assay was employed to identify active compound(s) in the most active EO from P. hispidimervium. The active compound was isolated and identified as asaricin, which gave an IC 50 value of 0.44 ± 0.02 mg/mL against AChE, comparable to galantamine with an IC 50 0.15 ± 0.01 mg/mL.

  18. Chemical sanitizers to control biofilms formed by two Pseudomonas species on stainless steel surface

    Directory of Open Access Journals (Sweden)

    Danila Soares Caixeta

    2012-03-01

    Full Text Available The biofilm formation of Pseudomonas aeruginosa and Pseudomonas fluorescens on AISI 304 stainless steel in the presence of reconstituted skim milk under different temperatures was conducted, and the potential of three chemical sanitizers in removing the mono-species biofilms formed was compared. Pseudomonas aeruginosa cultivated in skim milk at 28 °C presented better growth rate (10.4 log CFU.mL-1 when compared with 3.7 and 4.2 log CFU.mL-1 for P. aeruginosa and P. fluorescens cultivated at 7 °C, respectively. Pseudomonas aeruginosa formed biofilm when cultivated at 28 °C. However, only the adhesion of P. aeruginosa and P. fluorescens was observed when incubated at 7 °C. The sodium dichloroisocyanurate was the most efficient sanitizer in the reduction of the adhered P. aeruginosa cells at 7 and 28 °C and those on the biofilm, respectively. The hydrogen peroxide was more effective in the reduction of adhered cells of P. fluorescens at 7 °C.

  19. Using multiscale spatial models to assess potential surrogate habitat for an imperiled reptile.

    Directory of Open Access Journals (Sweden)

    Jennifer M Fill

    Full Text Available In evaluating conservation and management options for species, practitioners might consider surrogate habitats at multiple scales when estimating available habitat or modeling species' potential distributions based on suitable habitats, especially when native environments are rare. Species' dependence on surrogates likely increases as optimal habitat is degraded and lost due to anthropogenic landscape change, and thus surrogate habitats may be vital for an imperiled species' survival in highly modified landscapes. We used spatial habitat models to examine a potential surrogate habitat for an imperiled ambush predator (eastern diamondback rattlesnake, Crotalus adamanteus; EDB at two scales. The EDB is an apex predator indigenous to imperiled longleaf pine ecosystems (Pinus palustris of the southeastern United States. Loss of native open-canopy pine savannas and woodlands has been suggested as the principal cause of the species' extensive decline. We examined EDB habitat selection in the Coastal Plain tidewater region to evaluate the role of marsh as a potential surrogate habitat and to further quantify the species' habitat requirements at two scales: home range (HR and within the home range (WHR. We studied EDBs using radiotelemetry and employed an information-theoretic approach and logistic regression to model habitat selection as use vs.We failed to detect a positive association with marsh as a surrogate habitat at the HR scale; rather, EDBs exhibited significantly negative associations with all landscape patches except pine savanna. Within home range selection was characterized by a negative association with forest and a positive association with ground cover, which suggests that EDBs may use surrogate habitats of similar structure, including marsh, within their home ranges. While our HR analysis did not support tidal marsh as a surrogate habitat, marsh may still provide resources for EDBs at smaller scales.

  20. Bedload-surrogate monitoring technologies

    Science.gov (United States)

    Gray, John R.; Laronne, Jonathan B.; Marr, Jeffrey D.G.

    2010-01-01

    Advances in technologies for quantifying bedload fluxes and in some cases bedload size distributions in rivers show promise toward supplanting traditional physical samplers and sampling methods predicated on the collection and analysis of physical bedload samples. Four workshops held from 2002 to 2007 directly or peripherally addressed bedload-surrogate technologies, and results from these workshops have been compiled to evaluate the state-of-the-art in bedload monitoring. Papers from the 2007 workshop are published for the first time with this report. Selected research and publications since the 2007 workshop also are presented. Traditional samplers used for some or all of the last eight decades include box or basket samplers, pan or tray samplers, pressure-difference samplers, and trough or pit samplers. Although still useful, the future niche of these devices may be as a means for calibrating bedload-surrogate technologies operating with active- and passive-type sensors, in many cases continuously and automatically at a river site. Active sensors include acoustic Doppler current profilers (ADCPs), sonar, radar, and smart sensors. Passive sensors include geophones (pipes or plates) in direct contact with the streambed, hydrophones deployed in the water column, impact columns, and magnetic detection. The ADCP for sand and geophones for gravel are currently the most developed techniques, several of which have been calibrated under both laboratory and field conditions. Although none of the bedload-surrogate technologies described herein are broadly accepted for use in large-scale monitoring programs, several are under evaluation. The benefits of verifying and operationally deploying selected bedload-surrogate monitoring technologies could be considerable, providing for more frequent and consistent, less expensive, and arguably more accurate bedload data obtained with reduced personal risk for use in managing the world's sedimentary resources. Twenty-six papers are

  1. Discrimination and chemical phylogenetic study of seven species of Dendrobium using infrared spectroscopy combined with cluster analysis

    Science.gov (United States)

    Luo, Congpei; He, Tao; Chun, Ze

    2013-04-01

    Dendrobium is a commonly used and precious herb in Traditional Chinese Medicine. The high biodiversity of Dendrobium and the therapeutic needs require tools for the correct and fast discrimination of different Dendrobium species. This study investigates Fourier transform infrared spectroscopy followed by cluster analysis for discrimination and chemical phylogenetic study of seven Dendrobium species. Despite the general pattern of the IR spectra, different intensities, shapes, peak positions were found in the IR spectra of these samples, especially in the range of 1800-800 cm-1. The second derivative transformation and alcoholic extracting procedure obviously enlarged the tiny spectral differences among these samples. The results indicated each Dendrobium species had a characteristic IR spectra profile, which could be used to discriminate them. The similarity coefficients among the samples were analyzed based on their second derivative IR spectra, which ranged from 0.7632 to 0.9700, among the seven Dendrobium species, and from 0.5163 to 0.9615, among the ethanol extracts. A dendrogram was constructed based on cluster analysis the IR spectra for studying the chemical phylogenetic relationships among the samples. The results indicated that D. denneanum and D. crepidatum could be the alternative resources to substitute D. chrysotoxum, D. officinale and D. nobile which were officially recorded in Chinese Pharmacopoeia. In conclusion, with the advantages of high resolution, speediness and convenience, the experimental approach can successfully discriminate and construct the chemical phylogenetic relationships of the seven Dendrobium species.

  2. Use of Measured Species Class Concentrations with Chemical Kinetic Modeling for the Prediction of Autoxidation and Deposition of Jet Fuels (Postprint)

    National Research Council Canada - National Science Library

    Kuprowicz, Nicholas J; Zabarnick, Steven; West, Zachary J; Ervin, Jamie S

    2007-01-01

    .... In the present work, a chemical kinetic mechanism developed previously is refined to include the roles of key fuel species classes, such as phenols, reactive sulfur species, dissolved metals, and hydroperoxides...

  3. The effectiveness of surrogate taxa to conserve freshwater biodiversity

    Science.gov (United States)

    Stewart, David R.; Underwood, Zachary E.; Rahel, Frank J.; Walters, Annika W.

    2018-01-01

    Establishing protected areas has long been an effective conservation strategy, and is often based on more readily surveyed species. The potential of any freshwater taxa to be a surrogate of other aquatic groups has not been fully explored. We compiled occurrence data on 72 species of freshwater fish, amphibians, mussels, and aquatic reptiles for the Great Plains, Wyoming. We used hierarchical Bayesian multi-species mixture models and MaxEnt models to describe species distributions, and program Zonation to identify conservation priority areas for each aquatic group. The landscape-scale factors that best characterized aquatic species distributions differed among groups. There was low agreement and congruence among taxa-specific conservation priorities (<20%), meaning that no surrogate priority areas would include or protect the best habitats of other aquatic taxa. We found that common, wide-ranging aquatic species were included in taxa-specific priority areas, but rare freshwater species were not included. Thus, the development of conservation priorities based on a single freshwater aquatic group would not protect all species in the other aquatic groups.

  4. Interspecific and Intersexual Differences in the Chemical Composition of Floral Scent in Glochidion Species (Phyllanthaceae in South China

    Directory of Open Access Journals (Sweden)

    Daihong Huang

    2015-01-01

    Full Text Available Plants of the Glochidion (Phyllanthaceae genus are pollinated exclusively by host-specific Epicephala (Gracillariidae moths. Floral scent has been thought to play key role in the obligate pollination mutualism between Glochidion plants and Epicephala moths, but few studies have been reported about chemical variation in floral volatiles of Glochidion species in China. Floral volatiles of male and female flowers of five Glochidion species in south China were collected by dynamic headspace absorption technique and then were chemically analyzed by using gas chromatography-mass spectrometry. A total of 69 compounds were identified from floral scents of five investigated species. Glochidion hirsutum and G. zeylanicum showed no qualitative differences in floral scent, whereas there were clear variations of floral scent among other species (G. eriocarpum, G. daltonii, and G. sphaerogynum and also they distinctly differed from these two species. Male flowers emitted significantly more scent than female flowers. Glochidion plants exhibited qualitative and quantitative differences in floral scent between two sexes of flowers. The findings suggest that the volatile variation of floral scent among Glochidion species reflects adaptations to specific pollinators. Sexual dimorphism in floral scent has evolved to signal alternative rewards provided by each sex to Epicephala moths.

  5. Calorific Value and Chemical Composition of Five Semi-Arid Mexican Tree Species

    Directory of Open Access Journals (Sweden)

    Maginot Ngangyo-Heya

    2016-03-01

    Full Text Available The current global energy crisis has generated growing interest in looking for alternatives to traditional fossil fuels, presenting lignocellulosic materials as a promising resource for sustainable energy production. In this paper, the calorific values and chemical composition of the trunks, branches, twigs and leaves of five timber species of the semi-arid land of Mexico (Helietta parvifolia (Gray Benth., Ebenopsis ebano (Berl. Barneby, Acacia berlandieri (Benth., Havardia pallens (Benth. Britton & Rose and Acacia wrightii (Benth. were determined according to international standards. The results highlighted the calorific value ranges of 17.56 to 18.61 MJ kg−1 in trunks, 17.15 to 18.45 MJ kg−1 in branches, 17.29 to 17.92 MJ kg−1 in twigs, and 17.35to 19.36 MJ kg−1 in leaves. The pH presented an acidic trend (3.95–5.64. The content of mineral elements varied in trunks (1.09%–2.29%, branches (0.86%–2.75%, twigs (4.26%–6.76% and leaves (5.77%–11.79%, showing the higher proportion in Ca (57.03%–95.53%, followed by K (0.95%–19.21% and Mg (0.88%–13.47%. The highest amount of extractives was obtained in the methanolic solvent (3.96%–17.03%. The lignin recorded values of 28.78%–35.84% for trunks, 17.14%–31.39% for branches and 20.61%–29.92% for twigs. Lignin showed a moderately strong correlation (r = 0.66 with calorific value, but the best mathematical model was registered with the calorific value depending on the pH and lignin (R2 = 58.86%.

  6. Chemically reactive species in liquids generated by atmospheric-pressure plasmas and their roles in plasma medicine

    Energy Technology Data Exchange (ETDEWEB)

    Hamaguchi, Satoshi [Center for Atomic and Molecular Technologies, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2013-07-11

    Plasmas whose gas temperatures are close to room temperature may be generated in ambient air or a gas at atmospheric pressure with the use of low-frequency high voltage or low-power radio-frequency (RF) or microwave power applied to electrodes. Such plasmas can serve as a powerful source of free radicals and/or chemically reactive species that arise from atoms and molecules of the ambient gas. Recently use of such plasmas for medical purposes has attracted much attention as they can be implemented in possible medical devices that can cause blood coagulation, heal wounds, facilitate angiogenesis, sterilize surgical devices as well as living tissues without harming healthy cells, and selectively inactivate cancer cells. Especially of interest among reactive species generated by atmospheric-pressure plasmas (APP) are reactive oxygen species (ROS) and reactive nitrogen species (RNS) that are generated in liquid phase. Since most living tissues and cells are immersed in liquids (such as blood or culture media), reactive species generated by APPs in the gas phase are transported to the liquid phase and possibly converted to different types of reactive species therein before causing some influence on the tissues or cells. In this study, the rate equations are solved to evaluate concentrations of various reactive species in pure water that are originated by plasma reactions in atmosphere and possible effects of such species (including ROS/RNS) on living tissues and cells are discussed.

  7. Chemically reactive species in liquids generated by atmospheric-pressure plasmas and their roles in plasma medicine

    International Nuclear Information System (INIS)

    Hamaguchi, Satoshi

    2013-01-01

    Plasmas whose gas temperatures are close to room temperature may be generated in ambient air or a gas at atmospheric pressure with the use of low-frequency high voltage or low-power radio-frequency (RF) or microwave power applied to electrodes. Such plasmas can serve as a powerful source of free radicals and/or chemically reactive species that arise from atoms and molecules of the ambient gas. Recently use of such plasmas for medical purposes has attracted much attention as they can be implemented in possible medical devices that can cause blood coagulation, heal wounds, facilitate angiogenesis, sterilize surgical devices as well as living tissues without harming healthy cells, and selectively inactivate cancer cells. Especially of interest among reactive species generated by atmospheric-pressure plasmas (APP) are reactive oxygen species (ROS) and reactive nitrogen species (RNS) that are generated in liquid phase. Since most living tissues and cells are immersed in liquids (such as blood or culture media), reactive species generated by APPs in the gas phase are transported to the liquid phase and possibly converted to different types of reactive species therein before causing some influence on the tissues or cells. In this study, the rate equations are solved to evaluate concentrations of various reactive species in pure water that are originated by plasma reactions in atmosphere and possible effects of such species (including ROS/RNS) on living tissues and cells are discussed

  8. Ethical Problems Related to Surrogate Motherhood

    OpenAIRE

    Erdem Aydin

    2006-01-01

    Being unable to have children is an important problem for married couples. At present, new reproduction techniques help these couples while those who can not find any solution try new approaches. One of these is the phenomenon of surrogate motherhood, which is based upon an agreement between the infertile couple and surrogate mother. Surrogate mother may conceive with the sperm of the male of the involved couple as well as by the transfer of the embryo formed by invitro fertilization. Couples...

  9. Interpretations, perspectives and intentions in surrogate motherhood

    OpenAIRE

    van Zyl, L.; van Niekerk, A.

    2000-01-01

    In this paper we examine the questions "What does it mean to be a surrogate mother?" and "What would be an appropriate perspective for a surrogate mother to have on her pregnancy?" In response to the objection that such contracts are alienating or dehumanising since they require women to suppress their evolving perspective on their pregnancies, liberal supporters of surrogate motherhood argue that the freedom to contract includes the freedom to enter a contract to bear a child for an infertil...

  10. ETHICAL ISSUES IN THE SURROGATE MATERNITY PRACTICE

    OpenAIRE

    TÜRK, Rukiye; TERZİOĞLU, Fusun

    2014-01-01

    The assisted reproductive technology was initially considered to be a treatment tool for infertile couples. However, as it was started in time to use the uteri of other women for the embryos of the other ones, the concept of surrogate maternity appeared.The surrogate maternity is practiced in three types. In the first type of surrogate maternity, the sperm of the spouse of the prospective mother is inseminated with the ovum of the surrogate mother. The second method is the in-vitro inseminati...

  11. Surrogate Analysis and Index Developer (SAID) tool

    Science.gov (United States)

    Domanski, Marian M.; Straub, Timothy D.; Landers, Mark N.

    2015-10-01

    The use of acoustic and other parameters as surrogates for suspended-sediment concentrations (SSC) in rivers has been successful in multiple applications across the Nation. Tools to process and evaluate the data are critical to advancing the operational use of surrogates along with the subsequent development of regression models from which real-time sediment concentrations can be made available to the public. Recent developments in both areas are having an immediate impact on surrogate research and on surrogate monitoring sites currently (2015) in operation.

  12. Surrogate alcohol: what do we know and where do we go?

    Science.gov (United States)

    Lachenmeier, Dirk W; Rehm, Jürgen; Gmel, Gerhard

    2007-10-01

    Consumption of surrogate alcohols (i.e., nonbeverage alcohols and illegally produced alcohols) was shown to impact on different causes of death, not only poisoning or liver disease, and appears to be a major public health problem in Russia and elsewhere. A computer-assisted literature review on chemical composition and health consequences of "surrogate alcohol" was conducted and more than 70 references were identified. A wider definition of the term "surrogate alcohol" was derived, including both nonbeverage alcohols and illegally produced alcohols that contain nonbeverage alcohols. Surrogate alcohol may contain substances that cause severe health consequences including death. Known toxic constituents include lead, which may lead to chronic toxicity, and methanol, which leads to acute poisoning. On the other hand, the role of higher alcohols (e.g., propanol, isobutanol, and isoamyl alcohol) in the etiology of surrogate-associated diseases is currently unclear. Whether other constituents of surrogates have contributed to the high all-cause mortality over and above the effect of ethanol in recent studies also remains unclear. Given the high public health importance associated with the consumption of surrogate alcohols, further knowledge on its chemical composition is required as well as research on its links to various disease endpoints should be undertaken with priority. Some interventions to reduce the harm resulting from surrogate alcohol could be undertaken already at this point. For example, the use of methanol or methanol-containing wood alcohol should be abolished in denatured alcohol. Other possible surrogates (e.g., automobile products) should be treated with bittering agents to avoid consumption.

  13. The action of chemical and mechanical stresses on single and dual species biofilm removal of drinking water bacteria.

    Science.gov (United States)

    Gomes, I B; Lemos, M; Mathieu, L; Simões, M; Simões, L C

    2018-08-01

    The presence of biofilms in drinking water distribution systems (DWDS) is a global public health concern as they can harbor pathogenic microorganisms. Sodium hypochlorite (NaOCl) is the most commonly used disinfectant for microbial growth control in DWDS. However, its effect on biofilm removal is still unclear. This work aims to evaluate the effects of the combination of chemical (NaOCl) and mechanical stresses on the removal of single and dual species biofilms of two bacteria isolated from DWDS and considered opportunistic, Acinectobacter calcoaceticus and Stenotrophomonas maltophilia. A rotating cylinder reactor was successfully used for the first time in drinking water biofilm studies with polyvinyl chloride as substratum. The single and dual species biofilms presented different characteristics in terms of metabolic activity, mass, density, thickness and content of proteins and polysaccharides. Their complete removal was not achieved even when a high NaOCl concentrations and an increasing series of shear stresses (from 2 to 23Pa) were applied. In general, NaOCl pre-treatment did not improve the impact of mechanical stress on biofilm removal. Dual species biofilms were colonized mostly by S. maltophilia and were more susceptible to chemical and mechanical stresses than these single species. The most efficient treatment (93% biofilm removal) was the combination of NaOCl at 175mg·l -1 with mechanical stress against dual species biofilms. Of concern was the high tolerance of S. maltophilia to chemical and mechanical stresses in both single and dual species biofilms. The overall results demonstrate the inefficacy of NaOCl on biofilm removal even when combined with high shear stresses. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Comparison of two freshwater turtle species as monitors of radionuclide and chemical contamination: DNA damage and residue analysis

    International Nuclear Information System (INIS)

    Meyers-Schoene, L.; Shugart, L.R.; Beauchamp, J.J.; Walton, B.T.

    1993-01-01

    Two species of turtles that occupy different ecological niches were compared for their usefulness as monitors of freshwater ecosystems where both low-level radioactive and nonradioactive contaminants are present. The pond slider (Trachemys scripta) and common snapping turtle (Chelydra serpentina) were analyzed for the presence of 90 Sr, 137 Cs, 60 Co, and Hg, radionuclides and chemicals known to be present at the contaminated site, and single-strand breaks in liver DNA. The integrity of the DNA was examined by the alkaline unwinding assay, a technique that detects strand breaks as a biological marker of possible exposure to genotoxic agents. This measure of DNA damage was significantly increased in both species of turtles at the contaminated site compared with turtles of the same species at a reference site, and shows that contaminant-exposed populations were under more severe genotoxic stress than those at the reference site. The level of strand breaks observed at the contaminated site was high and in the range reported for other aquatic species exposed to deleterious concentrations of genotoxic agents such as chemicals and ionizing radiation. Statistically significantly higher concentrations of radionuclides and Hg were detected in the turtles from the contaminated area. Mercury concentrations were significantly higher in the more carnivorous snapping turtle compared with the slider; however, both species were effective monitors of the contaminants

  15. The physico-chemical 131I species in the exhaust air of a boiling water reactor (BWR 4)

    International Nuclear Information System (INIS)

    Deuber, H.

    1982-12-01

    In a German boiling water reactor, the physico-chemical 131 I species were determined in the plant exhaust and in the individual exhausts during 12 months. These measurements aimed in particular at determining the percentage and the source of the radiologically decisive elemental 131 I released to the environment. The retention of the 131 I species by iodine filters was also investigated. On an average, 45% of the 131 I discharged with the plant exhaust consisted of elemental iodine. This was largely released with the exhaust from the reactor building and from the turbine building. The other 55% consisted almost entirely of organic I. (orig./HP) [de

  16. The major differences in chemical composition and antibacterial activity of two closely related Leonotis species (Lamiaceae may have taxonomic value

    Directory of Open Access Journals (Sweden)

    J.N. Eloff

    2010-01-01

    Full Text Available Several Leonotis species are used widely for medicinal purposes in Africa. There have been drastic changes in the taxonomic treatment of Leonotis species during the past decade. Two species, L. dysophylla and L. microphylla occurring in Pretoria have been considered as varieties of the same species and as different species by different authors. Because Leonotis species are used widely as medicinal plants inter alia against bacterial infections, we decided to compare the chemical composition and antibacterial activity of four plants from each of two populations of the species. The chemical composition of acetone extracts of finely ground leaves was determined by thin layer chromatography followed by spraying with vanillin-sulphuric acid. There were hardly any differences between plants from the same population. There were major differences between the two species in the composition of pigments separated by thin layer chromatography and for compounds visualized with the vanillin-sulphuric acid spray reagent. This supported the viewpoint that the two species should not be considered as varieties. The major differences found in chemical composition indicate that chemical parameters may play an important role in resolving taxonomic differences. Because such a small quantity of material is needed, it may be feasible to analyze one or two leaves obtained from herbarium sheets as an additional taxonomic parameter. The antibacterial activity of the acetone extracts was determined using a two-fold serial dilution microplate method with tetrazolium violet as indicator of growth. The specific strains of the four most important nosocomial bacterial pathogens suggested by the United States National Committee for Clinical Laboratory Standards were used: Staphylococcus aureus (American Type Culture Collection 29213, Pseudomonas aeruginosa (ATCC 27853, Escherichia coli (ATCC 25922 and Enterococcus faecalis (ATCC 21212. The minimum inhibitory activity of the

  17. Organic Redox Species in Aqueous Flow Batteries: Redox Potentials, Chemical Stability and Solubility

    OpenAIRE

    Kristina Wedege; Emil Dražević; Denes Konya; Anders Bentien

    2016-01-01

    Organic molecules are currently investigated as redox species for aqueous low-cost redox flow batteries (RFBs). The envisioned features of using organic redox species are low cost and increased flexibility with respect to tailoring redox potential and solubility from molecular engineering of side groups on the organic redox-active species. In this paper 33, mainly quinone-based, compounds are studied experimentially in terms of pH dependent redox potential, solubility and stability, combined ...

  18. The influence of stream bed geomorphology on chemical species within the hyporheic zone over time and space

    Science.gov (United States)

    Quick, A. M.; Reeder, W. J.; Farrell, T. B.; Benner, S. G.; Tonina, D.; Feris, K. P.

    2017-12-01

    The hyporheic zone is well established as an important zone of biogeochemical activity in streams and rivers. Multiple large scale flume experiments were carried out to mimic bedform-controlled hyporheic zones in small streams. The laboratory setting allowed for geochemical measurement resolution and replicates that would not be possible in a natural setting. Two flume experiments that consisted of three small streams with variable sizes of bedform dunes were carried out in which chemical species were measured in the surface water and along hyporheic flow lines in the subsurface. The species measured included dissolved oxygen, pH, alkalinity, major cations (Na+, Mg2+, Ca2+, K+, Si4+, Al3+), anions (NO3-, NO2-, SO42-, PO43-, Cl-), and many trace elements (As, Sr, Co, Ni, Cu, Zn, Pb, U, V). Observed spatial and temporal trends reflect microbiological processes, changing redox conditions, and chemical weathering. In general, microbial respiration causes DO to decrease with residence time, leading to aerobic and anaerobic zones that influence redox-sensitive species and pH gradients that influence mineral solubility. Most other species concentrations, including those of major cations and trace elements, increase with residence time and generally decrease over time elapsed during the experiment. The different dune morphologies dictate flow velocities in the hyporheic zone; for most species, steeper dunes with higher velocities had lower concentrations at the end of the experiment, indicating the role of dune shape in the weathering rates of minerals in hyporheic sediment and the concentrations of dissolved species entering the surface water over time. Many of the observed trends can be applied, at least qualitatively, to understanding how these species will behave in natural settings. This insight will contribute to the understanding of many of the applications of the hyporheic zone (e.g. bioremediation, habitat, greenhouse gas emissions, etc.).

  19. Komponen Kimia Minyak Atsiridaun Tiga Jenis Piperaceae*[chemical Compounds of Essential Oil on Three Piperaceae Species

    OpenAIRE

    Jamal, Yuliasri

    2002-01-01

    Chemical analysis of leaves essential oil on three Piper species, P. malamiri, P. baccatum and P. majusculum was conducted using gas chromatography and mass spectrometry (GCMS) method.Chromatogram result showed 52, 56 and 47 peaks on leaves essential oil of P.malamiri, P.baccatum and P.majusculum respectively. Based on the peaks,it is known that isocaryofilene is the major, common and as the highest component found in the three essential oils, beside several other major components.

  20. On the segregation of chemical species in a clear boundary layer over heterogeneous land surfaces

    NARCIS (Netherlands)

    Ouwersloot, H.G.; Vilà-Guerau de Arellano, J.; Heerwaarden, van C.C.; Ganzeveld, L.N.; Krol, M.C.; Lelieveld, J.

    2011-01-01

    Using a Large-Eddy Simulation model, we have systematically studied the inability of boundary layer turbulence to efficiently mix reactive species. This creates regions where the species are accumulated in a correlated or anti-correlated way, thereby modifying the mean reactivity. We quantify this

  1. The Reparative Motive in Surrogate Mothers.

    Science.gov (United States)

    Kanefield, Linda

    1999-01-01

    Explores the motivations of surrogate mothers, focusing on underlying reparative motive--to compensate for or repair an earlier loss or sense of damage. Provides an overview of the typical surrogate's characteristics and personality, discusses the theoretical underpinnings of the reparative motive, and considers the tension between reparation and…

  2. 34 CFR 303.406 - Surrogate parents.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Surrogate parents. 303.406 Section 303.406 Education... DISABILITIES Procedural Safeguards General § 303.406 Surrogate parents. (a) General. Each lead agency shall ensure that the rights of children eligible under this part are protected if— (1) No parent (as defined...

  3. 34 CFR 300.519 - Surrogate parents.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Surrogate parents. 300.519 Section 300.519 Education... DISABILITIES Procedural Safeguards Due Process Procedures for Parents and Children § 300.519 Surrogate parents... parent (as defined in § 300.30) can be identified; (2) The public agency, after reasonable efforts...

  4. Imaging Seeker Surrogate for IRCM evaluation

    NARCIS (Netherlands)

    Schleijpen, H.M.A.; Carpenter, S.R.; Mellier, B.; Dimmeler, A.

    2007-01-01

    NATO-SCI-139 and its predecessor groups have more than a decade of history in the evaluation and recommendation of EO and IR Countermeasures against anti-aircraft missiles. Surrogate Seekers have proven to be a valuable tool for this work. The use of surrogate seekers in international co-operations

  5. Unravelling chemical priming machinery in plants: the role of reactive oxygen-nitrogen-sulfur species in abiotic stress tolerance enhancement.

    Science.gov (United States)

    Antoniou, Chrystalla; Savvides, Andreas; Christou, Anastasis; Fotopoulos, Vasileios

    2016-10-01

    Abiotic stresses severely limit crop yield and their detrimental effects are aggravated by climate change. Chemical priming is an emerging field in crop stress management. The exogenous application of specific chemical agents before stress events results in tolerance enhancement and reduction of stress impacts on plant physiology and growth. However, the molecular mechanisms underlying the remarkable effects of chemical priming on plant physiology remain to be elucidated. Reactive oxygen, nitrogen and sulfur species (RONSS) are molecules playing a vital role in the stress acclimation of plants. When applied as priming agents, RONSS improve stress tolerance. This review summarizes the recent knowledge on the role of RONSS in cell signalling and gene regulation contributing to abiotic stress tolerance enhancement. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Species diversity and chemical properties of litter influence non-additive effects of litter mixtures on soil carbon and nitrogen cycling.

    Directory of Open Access Journals (Sweden)

    Bing Mao

    Full Text Available Decomposition of litter mixtures generally cannot be predicted from the component species incubated in isolation. Therefore, such non-additive effects of litter mixing on soil C and N dynamics remain poorly understood in terrestrial ecosystems. In this study, litters of Mongolian pine and three dominant understory species and soil were collected from a Mongolian pine plantation in Northeast China. In order to examine the effects of mixed-species litter on soil microbial biomass N, soil net N mineralization and soil respiration, four single litter species and their mixtures consisting of all possible 2-, 3- and 4-species combinations were added to soils, respectively. In most instances, species mixing produced synergistic non-additive effects on soil microbial biomass N and soil respiration, but antagonistic non-additive effects on net N mineralization. Species composition rather than species richness explained the non-additive effects of species mixing on soil microbial biomass N and net N mineralization, due to the interspecific differences in litter chemical composition. Both litter species composition and richness explained non-additive soil respiration responses to mixed-species litter, while litter chemical diversity and chemical composition did not. Our study indicated that litter mixtures promoted soil microbial biomass N and soil respiration, and inhibited net N mineralization. Soil N related processes rather than soil respiration were partly explained by litter chemical composition and chemical diversity, highlighting the importance of functional diversity of litter on soil N cycling.

  7. Species diversity and chemical properties of litter influence non-additive effects of litter mixtures on soil carbon and nitrogen cycling.

    Science.gov (United States)

    Mao, Bing; Mao, Rong; Zeng, De-Hui

    2017-01-01

    Decomposition of litter mixtures generally cannot be predicted from the component species incubated in isolation. Therefore, such non-additive effects of litter mixing on soil C and N dynamics remain poorly understood in terrestrial ecosystems. In this study, litters of Mongolian pine and three dominant understory species and soil were collected from a Mongolian pine plantation in Northeast China. In order to examine the effects of mixed-species litter on soil microbial biomass N, soil net N mineralization and soil respiration, four single litter species and their mixtures consisting of all possible 2-, 3- and 4-species combinations were added to soils, respectively. In most instances, species mixing produced synergistic non-additive effects on soil microbial biomass N and soil respiration, but antagonistic non-additive effects on net N mineralization. Species composition rather than species richness explained the non-additive effects of species mixing on soil microbial biomass N and net N mineralization, due to the interspecific differences in litter chemical composition. Both litter species composition and richness explained non-additive soil respiration responses to mixed-species litter, while litter chemical diversity and chemical composition did not. Our study indicated that litter mixtures promoted soil microbial biomass N and soil respiration, and inhibited net N mineralization. Soil N related processes rather than soil respiration were partly explained by litter chemical composition and chemical diversity, highlighting the importance of functional diversity of litter on soil N cycling.

  8. The interactive surrogate travel system.

    Science.gov (United States)

    Nakajima, I; Ichimura, A; Juzoji, H; Mugita, K

    1999-01-01

    The Interactive Surrogate Travel (IST) system is based on the super-miniaturized system of virtual technology, Cave Automatic Virtual Environment (CAVE). Using bilateral virtual reality (VR-to-VR) communications, IST enables the testing of subjects via interactive communications. It appears that IST will find practical applications in the near future. We examined the utility of IST in medical treatment and psychiatric tests. Psychiatric symptoms reflect human pathos, which in turn are greatly influenced by culture. If these culture-bound symptoms can be adequately communicated between providers and clients of different cultures, we can develop effective telepsychiatric services across different societies and cultures. IST requires high-speed transmission and gigabyte circuits. A pilot project tested the utility of IST (through the use of optical fiber communications on earth) as a basis for experiments via the Gigabit satellite, to be launched in the year 2002.

  9. Use of Surrogate end points in HTA

    Directory of Open Access Journals (Sweden)

    Mangiapane, Sandra

    2009-08-01

    Full Text Available The different actors involved in health system decision-making and regulation have to deal with the question which are valid parameters to assess the health value of health technologies.So called surrogate endpoints represent in the best case preliminary steps in the casual chain leading to the relevant outcome (e. g. mortality, morbidity and are not usually directly perceptible by patients. Surrogate endpoints are not only used in trials of pharmaceuticals but also in studies of other technologies. Their use in the assessment of the benefit of a health technology is however problematic. In this report we intend to answer the following research questions: Which criteria need to be fulfilled for a surrogate parameter to be considered a valid endpoint? Which methods have been described in the literature for the assessment of the validity of surrogate endpoints? Which methodological recommendations concerning the use of surrogate endpoints have been made by international HTA agencies? Which place has been given to surrogate endpoints in international and German HTA reports? For this purpose, we choose three different approaches. Firstly, we conduct a review of the methodological literature dealing with the issue of surrogate endpoints and their validation. Secondly, we analyse current methodological guidelines of HTA agencies members of the International network of agencies for Health Technology Assessment (INAHTA as well as of agencies concerned with assessments for reimbursement purposes. Finally, we analyse the outcome parameter used in a sample of HTA reports available for the public. The analysis of methodological guidelines shows a very cautious position of HTA institutions regarding the use of surrogate endpoints in technology assessment. Surrogate endpoints have not been prominently used in HTA reports. None of the analysed reports based its conclusions solely on the results of surrogate endpoints. The analysis of German HTA reports shows a

  10. How taxonomic diversity, community structure, and sample size determine the reliability of higher taxon surrogates.

    Science.gov (United States)

    Neeson, Thomas M; Van Rijn, Itai; Mandelik, Yael

    2013-07-01

    Ecologists and paleontologists often rely on higher taxon surrogates instead of complete inventories of biological diversity. Despite their intrinsic appeal, the performance of these surrogates has been markedly inconsistent across empirical studies, to the extent that there is no consensus on appropriate taxonomic resolution (i.e., whether genus- or family-level categories are more appropriate) or their overall usefulness. A framework linking the reliability of higher taxon surrogates to biogeographic setting would allow for the interpretation of previously published work and provide some needed guidance regarding the actual application of these surrogates in biodiversity assessments, conservation planning, and the interpretation of the fossil record. We developed a mathematical model to show how taxonomic diversity, community structure, and sampling effort together affect three measures of higher taxon performance: the correlation between species and higher taxon richness, the relative shapes and asymptotes of species and higher taxon accumulation curves, and the efficiency of higher taxa in a complementarity-based reserve-selection algorithm. In our model, higher taxon surrogates performed well in communities in which a few common species were most abundant, and less well in communities with many equally abundant species. Furthermore, higher taxon surrogates performed well when there was a small mean and variance in the number of species per higher taxa. We also show that empirically measured species-higher-taxon correlations can be partly spurious (i.e., a mathematical artifact), except when the species accumulation curve has reached an asymptote. This particular result is of considerable practical interest given the widespread use of rapid survey methods in biodiversity assessment and the application of higher taxon methods to taxa in which species accumulation curves rarely reach an asymptote, e.g., insects.

  11. Analysis of Environmental Physical-Chemical Factors and Macroalga Species In The Coastal Water of Nusalaut, Central Maluku - Indonesia

    Directory of Open Access Journals (Sweden)

    Karel Melsasail

    2018-03-01

    Full Text Available The physical-chemical factors of environment are very influential on the presence and the growth of macrolaga in waters. Well-maintained water habitat is a good environment for the growth of macroalgae. A research has been conducted on the physicochemical environmental factors and the macroalgae species in the coastal waters of Nusalaut Island using transect method, and it was a survey research on four different observation stations. The results of the research showed that station I (Amet Village has the best physicochemical factors for the presence and the growth of macroalgae, compared to station II (Nalahia Village, station III (Sila Village and station IV (Leinitu Village. The most widely found macro algae are from the Rhodophyta class, with a total of 17 species of macroalgae, of which 15 species are found in station I.

  12. Consideration on thermodynamic data for predicting solubility and chemical species of elements in groundwater. Part 2: Np, Pu

    International Nuclear Information System (INIS)

    Yamaguchi, Tetsuji

    2000-11-01

    The solubility determines the release of a radionuclide from waste form and is used as a source term in radionuclide migration analysis in performance assessment of radioactive waste repository. Complexations of the radionuclide by ligands in groundwater affect the interaction between radionuclides and geologic media, thus affect their migration behavior. It is essential to estimate the solubility and to predict the chemical species for the radionuclide based on thermodynamic data. The thermodynamic data of aqueous species and compounds were reviewed and compiled for Np and Pu. Thermodynamic data were reviewed with emphasis on the hydrolysis and carbonate complexation that can dominate the speciation in groundwater. Thermodynamic data for other species were selected based on existing databases. Thermodynamic data for other important elements are under investigation, thus shown in an appendix for temporary use. (author)

  13. Chemical analogy in the case of hydrolysis species of F-elements

    International Nuclear Information System (INIS)

    Hirotake Moriyama; Hajimu Yamana; Kenso Fujiwara

    2001-01-01

    In spite of much importance, some of the thermodynamic data of actinide elements are still lacking, and the chemical behaviour of these elements is often predicted by considering chemical analogy, that is by taking the known data of the same and similar group elements. It is thus quite important to establish the basis and conditions for applying the chemical analogy. In the present study, some topics are discussed which are related with the chemical analogy for the hydrolysis behaviour of actinide ions. Systematic trends of the thermodynamic data of actinide ions, namely the solubility products and hydrolysis constants, are discussed by considering the results of recent measurements and by considering possible contributions of non-electrostatic interactions of actinide ions in addition to those of ordinary electrostatic ones. (authors)

  14. Surrogate Models for Online Monitoring and Process Troubleshooting of NBR Emulsion Copolymerization

    Directory of Open Access Journals (Sweden)

    Chandra Mouli R. Madhuranthakam

    2016-03-01

    Full Text Available Chemical processes with complex reaction mechanisms generally lead to dynamic models which, while beneficial for predicting and capturing the detailed process behavior, are not readily amenable for direct use in online applications related to process operation, optimisation, control, and troubleshooting. Surrogate models can help overcome this problem. In this research article, the first part focuses on obtaining surrogate models for emulsion copolymerization of nitrile butadiene rubber (NBR, which is usually produced in a train of continuous stirred tank reactors. The predictions and/or profiles for several performance characteristics such as conversion, number of polymer particles, copolymer composition, and weight-average molecular weight, obtained using surrogate models are compared with those obtained using the detailed mechanistic model. In the second part of this article, optimal flow profiles based on dynamic optimisation using the surrogate models are obtained for the production of NBR emulsions with the objective of minimising the off-specification product generated during grade transitions.

  15. Plutonium and surrogate fission products in a composite ceramic waste form

    International Nuclear Information System (INIS)

    Esh, D. W.; Frank, S. M.; Goff, K. M.; Johnson, S. G.; Moschetti, T. L.; O'Holleran, T.

    1999-01-01

    Argonne National Laboratory is developing a ceramic waste form to immobilize salt containing fission products and transuranic elements. Preliminary results have been presented for ceramic waste forms containing surrogate fission products such as cesium and the lanthanides. In this work results from scanning electron microscopy/energy dispersive spectroscopy and x-ray diffraction are presented in greater detail for ceramic waste forms containing surrogate fission products. Additionally, results for waste forms containing plutonium and surrogate fission products are presented. Most of the surrogate fission products appear to be silicates or aluminosilicates whereas the plutonium is usually found in an oxide form. There is also evidence for the presence of plutonium within the sodalite phase although the chemical speciation of the plutonium is not known

  16. ANATOMICAL CHARACTERISTICS AND CHEMICAL PROPERTIES OF THE BRANCH-WOOD OF Schizolobium amazonicum DUCKE SPECIES AND ITS POTENTIAL USES

    Directory of Open Access Journals (Sweden)

    Yusup Amin

    2013-10-01

    Full Text Available The scale of forest degradation and deforestation in Indonesia has inspired the use of lesser-known wood species, which are potentially abundant and so far has not much been utilized. Utilization of these woods should be imposed not only of the stem wood but also of the branch-wood portions. Schizolobiumamazonicum Ducke treeis one of those lesser-known species, and growing fast with an MAIof3.68 cm/year.In Indonesia this species is only found in the Purwodadi Botanical Garden. A research was conducted to study the basic characteristics (anatomical aspects and chemical properties of the branch-wood portion of this species. The branch-wood materials were obtained from the Purwodadi Botanical Garden situated in Pasuruan (East Java. The specimens used were the first branch of the trunk (stem of nine-year old S. amazonicum tree (= 29.46 cm. The branch-wood samples were then examined for the anatomical aspects (macroscopic and microscopic characteristics and chemical properties (chemical composition. Results revealed that the anatomical properties of S.amazonicum branch-wood exhibited close similarities to those of sengon wood; it was light in appearance and white in color. Its fiber averaged about 1500 μm, and based on the fiber dimension's derived values the branch- wood fiber of this species was categorized into first-class quality for pulp and paper manufacture. Further, the chemical composition of this branch-wood compared favorably with that of sengon and mangium wood. The composition of extractive content thatsoluble in alcohol-benzene; lignin; holocellulose; and α-cellulose of this branch-wood were 2.46; 28.71; 80.64; and 50.47%, respectively. The overall assessment implied that the branch-wood portion of S.amazonicum tree affords favorable potential to be developed as raw material for pulp and paper manufacture. Also, considering that both sengon and mangium woods were already used in the pulp and paper industries as well as the trees are

  17. Toxicity of fire retardant chemicals and fire suppressant foams to vertebrate and invertebrate wildlife species

    Science.gov (United States)

    Vyas, Nimish B.; Hill, Elwood F.

    1996-01-01

    Under laboratory conditions, acute single-dose oral toxicity tests (LD50) were conducted with three fire retardant chemicals (Fire-Trol GTS-R, Phos-Chek D75-F, and Fire-Trol LCG-R) and two fire suppressant foams (Silv-Ex and Phos-Chek WD-881) to determine effects on adult northern bobwhite, American kestrel, red-winged blackbird, and white-footed mouse. In addition, earthworms were exposed (LC50) for 14 days in treated soil.In general, no toxic responses were evident. For northern bobwhite, the LD50 for all five chemicals was >2000 mg a.l./kg of body mass. American kestrels regurgitated all chemicals except Silv-ex; LD50s all exceeded 2000 mg/kg. The LD50 for red-winged blackbird was also >2000 mg/kg for all chemicals except Fire-Trol GTS-R which is currently undergoing further testing. In addition, the LD50 for white-footed mouse was >2000 mg/kg for Phos-Chek D75F. The 14-day LC50 for earthworms was >1000 ppm for all chemicals. Therefore, we concluded that these retardants and foams do not pose an acute hazard to adult birds, mammals, or earthworms. However, ecological studies to evaluate the potential effects of these formulations on vertebrate behavior and population dynamics are in progress.

  18. Spatial distribution and temporal variation of chemical species in the bulk atmospheric aerosols collected at the Okinawa archipelago, Japan

    Science.gov (United States)

    Handa, D.; Somada, Y.; Ijyu, M.; Azechi, S.; Nakaema, F.; Arakaki, T.; Tanahara, A.

    2009-12-01

    The economic development and population growth in recent Asia have been increasing air pollution. A computer simulation study showed that air pollutants emitted from Asian continent could spread quickly within northern hemisphere. We initiated a study to elucidate the special distribution and chemical characterization of atmospheric aerosols around Okinawa archipelago, Japan. Okinawa Island is situated approximately 1500 km south of Tokyo, Japan, 2000 km southeast of Beijing, China, and 1000 km south of South Korea. Its location in Asia is well suited for studying long-range transport of air pollutants in East Asia because maritime air mass prevails during summer, while continental air mass dominates during fall, winter, and spring. The maritime air mass data can be seen as background and can be compared with continental air masses which have been affected by anthropogenic activities. We simultaneously collected bulk aerosol samples by using the same types of high volume air samplers at Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS, Okinawa Island), Kume Island (ca. 160 km south-west of CHAAMS) and Minami-daitou Island (ca. 320 km south-east of CHAAMS). We determined the concentrations of water-soluble anions, cations and dissolved organic carbon (DOC) using ion chromatography, atomic absorption spectrometry, and total organic carbon analyzer, respectively. We report and discuss spatial distribution and temporal variation of chemical species concentrations in bulk atmospheric aerosols collected during July, 2008 to July, 2009. We determine “background” concentration of chemical components in Okinawa archipelago. We then compare each chemical component among CHAAMS, Kume Island and Minami-daito Island to elucidate the influence of the long-range transport of chemical species from Asian continent.

  19. Volatile constituents from Baccharis spp. L. (Asteraceae): Chemical support for the conservation of threatened species in Uruguay.

    Science.gov (United States)

    Minteguiaga, Manuel; Andrés González, H; Cassel, Eduardo; Umpierrez, Noelia; Fariña, Laura; Dellacassa, Eduardo

    2018-03-14

    Chemical bioprospecting is an important tool for generating knowledge regarding local human-threatened floras and for conservation management. For Baccharis L. (Asteraceae), several volatile components have been reported for Brazil, Argentina, Bolivia, and Chile as a result of bioprospection, but not for Uruguayan flora, which is composed of more than 50 native species. In this work, through collection of aerial parts of different species and volatile simultaneous-distillation extraction and gas chromatography-mass spectrometry analyses, 12 native species of Baccharis were studied (B. articulata, B. cultrata, B. genistifolia, B. gibertii, B. gnaphalioides, B. ochracea, B. phyteumoides, B. punctulata, B. crispa, B. dracunculifolia, B. linearifolia subsp. linearifolia, and B. spicata). A detailed analysis of the male and female volatile composition was conducted for the last four species. The profiles of B. cultrata, B. genistifolia, B. gibertii, and B. gnaphalioides are reported for the first time. Because half of the species analysed in this work are in Uruguay and are threatened or potentially threatened by human economic activities, the importance of their conservation as natural, sustainable resources is highlighted. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  20. Hypothesis test for synchronization: twin surrogates revisited.

    Science.gov (United States)

    Romano, M Carmen; Thiel, Marco; Kurths, Jürgen; Mergenthaler, Konstantin; Engbert, Ralf

    2009-03-01

    The method of twin surrogates has been introduced to test for phase synchronization of complex systems in the case of passive experiments. In this paper we derive new analytical expressions for the number of twins depending on the size of the neighborhood, as well as on the length of the trajectory. This allows us to determine the optimal parameters for the generation of twin surrogates. Furthermore, we determine the quality of the twin surrogates with respect to several linear and nonlinear statistics depending on the parameters of the method. In the second part of the paper we perform a hypothesis test for phase synchronization in the case of experimental data from fixational eye movements. These miniature eye movements have been shown to play a central role in neural information processing underlying the perception of static visual scenes. The high number of data sets (21 subjects and 30 trials per person) allows us to compare the generated twin surrogates with the "natural" surrogates that correspond to the different trials. We show that the generated twin surrogates reproduce very well all linear and nonlinear characteristics of the underlying experimental system. The synchronization analysis of fixational eye movements by means of twin surrogates reveals that the synchronization between the left and right eye is significant, indicating that either the centers in the brain stem generating fixational eye movements are closely linked, or, alternatively that there is only one center controlling both eyes.

  1. Surrogacy: the experiences of surrogate mothers.

    Science.gov (United States)

    Jadva, Vasanti; Murray, Clare; Lycett, Emma; MacCallum, Fiona; Golombok, Susan

    2003-10-01

    This study examined the motivations, experiences and psychological consequences of surrogacy for surrogate mothers. Thirty-four women who had given birth to a surrogate child approximately 1 year previously were interviewed by trained researchers, and the data rated using standardized coding criteria. Information was obtained on: (i) reasons for the woman's decision to become a surrogate mother; (ii) her retrospective view of the relationship with the commissioning couple before the pregnancy, during the pregnancy, and after the birth; (iii) her experiences during and after relinquishing the child; and (iv) how others reacted to her decision to become a surrogate mother. It was found that surrogate mothers do not generally experience major problems in their relationship with the commissioning couple, in handing over the baby, or from the reactions of those around them. The emotional problems experienced by some surrogate mothers in the weeks following the birth appeared to lessen over time. Surrogate mothers do not appear to experience psychological problems as a result of the surrogacy arrangement.

  2. So not mothers: responsibility for surrogate orphans.

    Science.gov (United States)

    Parks, Jennifer A; Murphy, Timothy F

    2018-04-12

    The law ordinarily recognises the woman who gives birth as the mother of a child, but in certain jurisdictions, it will recognise the commissioning couple as the legal parents of a child born to a commercial surrogate. Some commissioning parents have, however, effectively abandoned the children they commission, and in such cases, commercial surrogates may find themselves facing unexpected maternal responsibility for children they had fully intended to give up. Any assumption that commercial surrogates ought to assume maternal responsibility for abandoned children runs contrary to the moral suppositions that typically govern contract surrogacy, in particular, assumptions that gestational carriers are not 'mothers' in any morally significant sense. In general, commercial gestational surrogates are almost entirely conceptualised as 'vessels'. In a moral sense, it is deeply inconsistent to expect commercial surrogates to assume maternal responsibility simply because commissioning parents abandon children for one reason or another. We identify several instances of child abandonment and discuss their implications with regard to the moral conceptualisation of commercial gestational surrogates. We conclude that if gestational surrogates are to remain conceptualised as mere vessels, they should not be expected to assume responsibility for children abandoned by commissioning parents, not even the limited responsibility of giving them up for adoption or surrendering them to the state. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  3. Studies on the origin and transformation of selenium and its chemical species along the process of petroleum refining

    Science.gov (United States)

    Stivanin de Almeida, Cibele M.; Ribeiro, Anderson S.; Saint'Pierre, Tatiana D.; Miekeley, Norbert

    2009-06-01

    Inductively coupled plasma optical emission spectrometry and mass spectrometry (ICPMS), the latter hyphenated to flow injection hydride generation, electrothermal vaporization or ion chromatography, have been applied to the chemical characterization of crude oil, aqueous process stream samples and wastewaters from a petroleum refinery, in order to get information on the behavior of selenium and its chemical species along effluent generation and treatment. Multielemental characterization of these effluents by ICPMS revealed a complex composition of most of them, with high salinity and potential spectral and non-spectral interferents present. For this reason, a critical re-assessment of the analytical techniques for the determination of total selenium and its species was performed. Methane was employed as gas in dynamic reaction cell ICPMS and cell parameters were optimized for a simulated brine matrix and for diluted aqueous solutions to match the expected process and treated wastewaters samples. The signal-to-background ratios for 78Se and 80Se were used as criteria in optimization, the first isotope resulting in better detection limits for the simulated brine matrix ( 78Se: 0.07 μg L - 1 , 80Se: 0.31 μg L - 1 ). A large variability in the concentration of selenium (from crude oil samples in the refinery here investigated, which may explain the pronounced concentrations changes of this element measured in aqueous process stream and wastewater samples. Highest concentrations of total selenium were analyzed in samples from the hydrotreater (up to about 1800 μg L - 1 ). The predominance of selenocyanate (SeCN -) was observed in most of the wastewaters so far investigated, but also other species were detected with retention times different from Se(IV), Se(VI) and SeCN -. Colloidal selenium (Se 0) was the only Se-species observed in samples from the atmospheric distillation unit, but was also identified in other samples, most probably formed by the decomposition of

  4. A High Throughput Ambient Mass Spectrometric Approach to Species Identification and Classification from Chemical Fingerprint Signatures

    Science.gov (United States)

    Musah, Rabi A.; Espinoza, Edgard O.; Cody, Robert B.; Lesiak, Ashton D.; Christensen, Earl D.; Moore, Hannah E.; Maleknia, Simin; Drijfhout, Falko P.

    2015-01-01

    A high throughput method for species identification and classification through chemometric processing of direct analysis in real time (DART) mass spectrometry-derived fingerprint signatures has been developed. The method entails introduction of samples to the open air space between the DART ion source and the mass spectrometer inlet, with the entire observed mass spectral fingerprint subjected to unsupervised hierarchical clustering processing. A range of both polar and non-polar chemotypes are instantaneously detected. The result is identification and species level classification based on the entire DART-MS spectrum. Here, we illustrate how the method can be used to: (1) distinguish between endangered woods regulated by the Convention for the International Trade of Endangered Flora and Fauna (CITES) treaty; (2) assess the origin and by extension the properties of biodiesel feedstocks; (3) determine insect species from analysis of puparial casings; (4) distinguish between psychoactive plants products; and (5) differentiate between Eucalyptus species. An advantage of the hierarchical clustering approach to processing of the DART-MS derived fingerprint is that it shows both similarities and differences between species based on their chemotypes. Furthermore, full knowledge of the identities of the constituents contained within the small molecule profile of analyzed samples is not required. PMID:26156000

  5. Chemical composition of hydroethanolic extracts from five species of the Passiflora genus

    Directory of Open Access Journals (Sweden)

    Marna E Sakalem

    2012-09-01

    Full Text Available The diversified genus Passiflora is well distributed all over Brazil, and many species have been long used as medicinal plants, mainly against anxiety disturbances. This effect has been attributed to its rich flavonoid composition. Flavonoids’ main class, flavonoid glycosides, has presented central action, particularly as sedative-hypnotic, anxiolytic and analgesic. The objective of the present study was to make a phytochemical screening of five little studied Passiflora species, in order to evaluate their phenolic composition. For this aim, HPLC-DAD-ESI-MS/MS was used. After the preparation of the hydroalcoholic extracts, each species was evaluated by direct injection electrospray ionization (ESI and tandem mass spectrometry. Although belonging to the same genus, the composition of each species presented particularities; this justifies the importance of studies aiming for the phenolic composition of different Passiflora species. Flavones C-glycosides were detected in all extracts, and are found as the main constituents in P. vitifolia, P. coccinea, P. bahiensis and P. sidifolia. In this last one, flavone-6,8-di-C-glycoside, apigenin-6-C-rhamnosyl-8-C-arabinoside are present in high content. Cyclopassiflosides were found in high content together with cyanogenic glycosides in P. quadrangularis, while in P. coccinea, besides flavones-C-glycosides were also found procyanidins.

  6. Chemical composition of hydroethanolic extracts from five species of the Passiflora genus

    Directory of Open Access Journals (Sweden)

    Marna E Sakalem

    2012-12-01

    Full Text Available The diversified genus Passiflora is well distributed all over Brazil, and many species have been long used as medicinal plants, mainly against anxiety disturbances. This effect has been attributed to its rich flavonoid composition. Flavonoids’ main class, flavonoid glycosides, has presented central action, particularly as sedative-hypnotic, anxiolytic and analgesic. The objective of the present study was to make a phytochemical screening of five little studied Passiflora species, in order to evaluate their phenolic composition. For this aim, HPLC-DAD-ESI-MS/MS was used. After the preparation of the hydroalcoholic extracts, each species was evaluated by direct injection electrospray ionization (ESI and tandem mass spectrometry. Although belonging to the same genus, the composition of each species presented particularities; this justifies the importance of studies aiming for the phenolic composition of different Passiflora species. Flavones C-glycosides were detected in all extracts, and are found as the main constituents in P. vitifolia, P. coccinea, P. bahiensis and P. sidifolia. In this last one, flavone-6,8-di-C-glycoside, apigenin-6-C-rhamnosyl-8-C-arabinoside are present in high content. Cyclopassiflosides were found in high content together with cyanogenic glycosides in P. quadrangularis, while in P. coccinea, besides flavones-C-glycosides were also found procyanidins.

  7. Phytotoxic effects and chemical analysis of leaf extracts from three Phytolaccaceae species in South Korea.

    Science.gov (United States)

    Kim, Yong Ok; Johnson, Jon D; Lee, Eun Ju

    2005-05-01

    We analyzed phenolic compounds and other elements in leaf extracts and compared morphology of three species of the Phytolaccaceae family found in South Korea. To test allelochemical effects of the three Phytolacca species, we also examined seed germination and dry weight of seedlings of Lactuca indica and Sonchus oleraceus treated with leaf extracts. The concentrations of total phenolic compounds were exotic Phytolacca esculenta (3.9 mg/l), native Phytolacca insularis (4.4 mg/l), and exotic Phytolacca americana (10.2 mg/l). There was no significant difference in concentrations between P. esculenta and P. insularis, but the concentration of total phenolics in P. americana was two times higher than either P. esculenta or P. insularis. Analysis of aqueous extracts by HPLC showed seven phenolic compounds (gallic acid, protocatechuic acid, chlorogenic acid, caffeic acid, m-hydroxybenzoic acid, p-coumaric acid, and cinnamic acid). Total phenolics in P. americana were eight to 16 times higher than either P. esculenta or P. insularis, respectively. P. americana inhibited seed germination and dry weight of the two assay species. The phytotoxic effects of the two Phytolacca species were different, despite the fact that P. esculenta and P. insularis had similar levels of total phenolic compounds. We also found that P. americana had invaded Ullung Island, which suggested that P. americana had excellent adaptability to the environment. The three species of Phytolaccaceae in South Korea can be distinguished by their different allelopathic potentials and morphologies.

  8. Effects of Pig Slurry Application and Crops on Phosphorus Content in Soil and the Chemical Species in Solution

    Directory of Open Access Journals (Sweden)

    Lessandro De Conti

    2015-06-01

    Full Text Available The application of pig slurry rates and plant cultivation can modify the soil phosphorus (P content and distribution of chemical species in solution. The purpose of this study was to evaluate the total P, available P and P in solution, and the distribution of chemical P species in solution, in a soil under longstanding pig slurry applications and crop cultivation. The study was carried out in soil columns with undisturbed structure, collected in an experiment conducted for eight years in the experimental unit of the Universidade Federal de Santa Maria (UFSM, Santa Maria (RS. The soil was an Argissolo Vermelho distrófico arênico (Typic Hapludalf, subjected to applications of 0, 20, 40, and 80 m3 ha-1 pig slurry. Soil samples were collected from the layers 0-5, 5-10, 10-20, 20-30, 30-40, and 40-60 cm, before and after black oat and maize grown in a greenhouse, for the determination of available P, total P and P in the soil solution. In the solution, the concentration of the major cations, anions, dissolved organic carbon (DOC, and pH were determined. The distribution of chemical P species was determined by software Visual Minteq. The 21 pig slurry applications increased the total P content in the soil to a depth of 40 cm, and the P extracted by Mehlich-1 and from the solution to a depth of 30 cm. Successive applications of pig slurry changed the balance between the solid and liquid phases in the surface soil layers, increasing the proportion of the total amount of P present in the soil solution, aside from changing the chemical species in the solution, reducing the percentage complexed with Al and increasing the one complexed with Ca and Mg in the layers 0-5 and 5-10 cm. Black oat and maize cultivation increased pH in the solution, thereby increasing the proportion of HPO42- and reducing H2PO4- species.

  9. Chemical composition of the essential oil and hexanic fraction of Lippia and Lantana species

    Directory of Open Access Journals (Sweden)

    Pâmela S. Silva

    2010-11-01

    Full Text Available A comparison between two extraction approaches of volatiles compounds from six species of Verbenaceae collected at Serra do Cipó, Minas Gerais, Brazil was done. The essential oil and hexanic fraction of leaves from two Lantana and four Lippia species collected in two different seasons were analyzed by GC/MS. Among various identified compounds from both extraction methods the majority of species showed major amounts of β-caryophyllene followed by germacrene D, bicyclogermacrene and α-pinene. Few differences were observed between the composition of essential oil and the hexanic fraction regarding the two studied genera. These results suggest that the analysis of hexanic fraction can be used, as an alternative way, to analyze the volatile compounds of the essential oil.

  10. Chemical Composition and Seasonality of Aromatic Mediterranean Plant Species by NMR-Based Metabolomics

    Directory of Open Access Journals (Sweden)

    Monica Scognamiglio

    2015-01-01

    Full Text Available An NMR-based metabolomic approach has been applied to analyse seven aromatic Mediterranean plant species used in traditional cuisine. Based on the ethnobotanical use of these plants, the approach has been employed in order to study the metabolic changes during different seasons. Primary and secondary metabolites have been detected and quantified. Flavonoids (apigenin, quercetin, and kaempferol derivatives and phenylpropanoid derivatives (e.g., chlorogenic and rosmarinic acid are the main identified polyphenols. The richness in these metabolites could explain the biological properties ascribed to these plant species.

  11. Chemical Composition and Seasonality of Aromatic Mediterranean Plant Species by NMR-Based Metabolomics.

    Science.gov (United States)

    Scognamiglio, Monica; D'Abrosca, Brigida; Esposito, Assunta; Fiorentino, Antonio

    2015-01-01

    An NMR-based metabolomic approach has been applied to analyse seven aromatic Mediterranean plant species used in traditional cuisine. Based on the ethnobotanical use of these plants, the approach has been employed in order to study the metabolic changes during different seasons. Primary and secondary metabolites have been detected and quantified. Flavonoids (apigenin, quercetin, and kaempferol derivatives) and phenylpropanoid derivatives (e.g., chlorogenic and rosmarinic acid) are the main identified polyphenols. The richness in these metabolites could explain the biological properties ascribed to these plant species.

  12. Primary Reference Fuels (PRFs) as Surrogates for Low Sensitivity Gasoline Fuels

    KAUST Repository

    Bhavani Shankar, Vijai Shankar

    2016-04-05

    Primary Reference Fuels (PRFs) - binary mixtures of n-heptane and iso-octane based on Research Octane Number (RON) - are popular gasoline surrogates for modeling combustion in spark ignition engines. The use of these two component surrogates to represent real gasoline fuels for simulations of HCCI/PCCI engines needs further consideration, as the mode of combustion is very different in these engines (i.e. the combustion process is mainly controlled by the reactivity of the fuel). This study presents an experimental evaluation of PRF surrogates for four real gasoline fuels termed FACE (Fuels for Advanced Combustion Engines) A, C, I, and J in a motored CFR (Cooperative Fuels Research) engine. This approach enables the surrogate mixtures to be evaluated purely from a chemical kinetic perspective. The gasoline fuels considered in this study have very low sensitivities, S (RON-MON), and also exhibit two-stage ignition behavior. The first stage heat release, which is termed Low Temperature Heat Release (LTHR), controls the combustion phasing in this operating mode. As a result, the performance of the PRF surrogates was evaluated by its ability to mimic the low temperature chemical reactivity of the real gasoline fuels. This was achieved by comparing the LTHR from the engine pressure histories. The PRF surrogates were able to consistently reproduce the amount of LTHR, closely match the phasing of LTHR, and the compression ratio for the start of hot ignition of the real gasoline fuels. This suggests that the octane quality of a surrogate fuel is a good indicator of the fuel’s reactivity across low (LTC), negative temperature coefficient (NTC), and high temperature chemical (HTC) reactivity regimes.

  13. Evaluation of thermal, chemical, and mechanical seed scarification methods for 4 Great Basin lupine species

    Science.gov (United States)

    Covy D. Jones; Mikel R. Stevens; Von D. Jolley; Bryan G. Hopkins; Scott L. Jensen; Dave Turner; Jason M. Stettler

    2016-01-01

    Seeds of most Great Basin lupine (Lupinus spp. [Fabaceae]) species are physically dormant and thus, difficult to establish in uniform stands in seed production fields. We designed this study to examine 5 seed scarification techniques, each with 11 levels of application (including a non-scarified control), to reduce the physical seed dormancy of longspur lupine...

  14. Primary Reference Fuels (PRFs) as Surrogates for Low Sensitivity Gasoline Fuels

    KAUST Repository

    Bhavani Shankar, Vijai Shankar; Sajid, Muhammad Bilal; Al-Qurashi, Khalid; Atef, Nour; Al Khesho, Issam; Ahmed, Ahfaz; Chung, Suk-Ho; Roberts, William L.; Morganti, Kai; Sarathy, Mani

    2016-01-01

    This study presents an experimental evaluation of PRF surrogates for four real gasoline fuels termed FACE (Fuels for Advanced Combustion Engines) A, C, I, and J in a motored CFR (Cooperative Fuels Research) engine. This approach enables the surrogate mixtures to be evaluated purely from a chemical kinetic perspective. The gasoline fuels considered in this study have very low sensitivities, S (RON-MON), and also exhibit two-stage ignition behavior. The first stage heat release, which is termed Low Temperature Heat Release (LTHR), controls the combustion phasing in this operating mode. As a result, the performance of the PRF surrogates was evaluated by its ability to mimic the low temperature chemical reactivity of the real gasoline fuels. This was achieved by comparing the LTHR from the engine pressure histories. The PRF surrogates were able to consistently reproduce the amount of LTHR, closely match the phasing of LTHR, and the compression ratio for the start of hot ignition of the real gasoline fuels. This suggests that the octane quality of a surrogate fuel is a good indicator of the fuel’s reactivity across low (LTC), negative temperature coefficient (NTC), and high temperature chemical (HTC) reactivity regimes.

  15. CHEMICAL COMPOSITION AND in vitro GAS PRODUCTION OF SOME LEGUME BROWSE SPECIES IN SUBTROPICAL AREAS OF MEXICO

    Directory of Open Access Journals (Sweden)

    Carlos A Garcia Montes de Oca

    2011-03-01

    Full Text Available The objective of the present study was to determine the chemical composition and in vitro gas production of different legume and wild arboreal pods. Seven seeds of legume browse species, Mexican calabash (Crescentia alata, esculent leadtree (Leucaena esculenta, guamuchil (Phitecellobium dulce, bastard cedar (Guazuma ulmifolia, needle bush (Acacia farnesiana, mimosa (Mimosa sp. and elephant ear tree (Enterolobium cyclocarpum. Were evaluated for their chemical composition (g/kg DM and in vitro gas production pattern. Crude Protein was higher for L. esculenta (220 and lower for G. ulmifolia (70. Neutral and acid detergent fiber were higher for G. ulmifolia (687 and 554 and lower for A. farnesiana (267 and 176. Lignin was higher for Mimosa sp. (219 and lower for P. dulce (81. Total gas production (ml gas/g DM of P. dulce (187 and E. cyclocarpum (164 were higher (P

  16. Establishment and intra-/inter-laboratory validation of a standard protocol of reactive oxygen species assay for chemical photosafety evaluation.

    Science.gov (United States)

    Onoue, Satomi; Hosoi, Kazuhiro; Wakuri, Shinobu; Iwase, Yumiko; Yamamoto, Toshinobu; Matsuoka, Naoko; Nakamura, Kazuichi; Toda, Tsuguto; Takagi, Hironori; Osaki, Naoto; Matsumoto, Yasuhiro; Kawakami, Satoru; Seto, Yoshiki; Kato, Masashi; Yamada, Shizuo; Ohno, Yasuo; Kojima, Hajime

    2013-11-01

    A reactive oxygen species (ROS) assay was previously developed for photosafety evaluation of pharmaceuticals, and the present multi-center study aimed to establish and validate a standard protocol for ROS assay. In three participating laboratories, two standards and 42 coded chemicals, including 23 phototoxins and 19 nonphototoxic drugs/chemicals, were assessed by the ROS assay according to the standardized protocol. Most phototoxins tended to generate singlet oxygen and/or superoxide under UV-vis exposure, but nonphototoxic chemicals were less photoreactive. In the ROS assay on quinine (200 µm), a typical phototoxic drug, the intra- and inter-day precisions (coefficient of variation; CV) were found to be 1.5-7.4% and 1.7-9.3%, respectively. The inter-laboratory CV for quinine averaged 15.4% for singlet oxygen and 17.0% for superoxide. The ROS assay on 42 coded chemicals (200 µm) provided no false negative predictions upon previously defined criteria as compared with the in vitro/in vivo phototoxicity, although several false positives appeared. Outcomes from the validation study were indicative of satisfactory transferability, intra- and inter-laboratory variability, and predictive capacity of the ROS assay. Copyright © 2012 John Wiley & Sons, Ltd.

  17. Consideration on thermodynamic data for predicting solubility and chemical species of elements in groundwater. Part 1: Tc, U, Am

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Tetsuji; Takeda, Seiji [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1999-01-01

    The solubility determines the release of radionuclides from waste form and is used as a source term in radionuclide migration analysis in performance assessment of radioactive waste repository. Complexations of radionuclides by ligands in groundwater affect the interaction between radionuclides and geologic media, thus affect their migration behavior. Thermodynamic data for Tc, Am and U were reviewed and compiled to be used for predicting the solubility and chemical species in groundwater. Thermodynamic data were reviewed with emphasis on the hydrolysis and carbonate complexation that can dominate the speciation in typical groundwater. Thermodynamic data for other species were selected based on existing database. Thermodynamic data for other important elements are under investigation, thus shown in an appendix for temporary use. (author)

  18. The physico-chemical I-131 species in the exhaust air of a boiling water reactor (BWR 5)

    International Nuclear Information System (INIS)

    Deuber, H.

    1984-02-01

    In a German boiling water reactor, the pysico-chemical I-131 species were determined in the plant exhaust and in the individual exhausts during four months. These measurements aimed in particular at determining the percentage and the source of the radiologically decisive elemental I-131 released to the environment. On an average 13% of the I-131 discharged with the plant exhaust consisted of elemental iodine. This was largely released with the exhausts from the reactor building and from the turbine building. The main component was organic-bound I. (orig./HP) [de

  19. Chemical species of iodine in some seaweeds. Pt. 2. Iodine-bound biological macromolecules

    International Nuclear Information System (INIS)

    Xiaolin Hou; Chifang Chai; Xiaojun Yan

    2000-01-01

    The distribution of iodine in various biological macromolecules in Sargassum kjellmanianum was studied using neutron activation analysis combined with chemical and biochemical separation techniques. The results indicate that iodine is mainly bound with protein, part of iodine with pigment and polyphenol, and little with polysaccharides, such as algin, fucoidan and cellulose. This result is significant for the mechanism of enriching iodine of algae and utilization of alga iodine. (author)

  20. The smell of change: warming affects species interactions mediated by chemical information

    Czech Academy of Sciences Publication Activity Database

    Sentis, Arnaud; Ramon-Portugal, F.; Brodeur, J.; Hemptinne, J.-L.

    2015-01-01

    Roč. 21, č. 10 (2015), s. 3586-3594 ISSN 1354-1013 Grant - others:European Social Fund(CZ) CZ.1.07/2.3.00/30.0049 Institutional support: RVO:60077344 Keywords : chemical communication * climate change * insects Subject RIV: EH - Ecology, Behaviour Impact factor: 8.444, year: 2015 http://onlinelibrary.wiley.com/doi/10.1111/gcb.12932/abstract

  1. CHEMICALS

    CERN Multimedia

    Medical Service

    2002-01-01

    It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546

  2. Study of the chemical species of fluorine 18 produced by neutron irradiation of lithium aluminate

    International Nuclear Information System (INIS)

    Jimenez-Becerril, J.

    1990-01-01

    In the present work, the chemical form of fluorine-18 obtained by means of the neutron irradiated lithium aluminate was studied, in order to know its chemical behavior and to observe if it volatilizes and adheres to the walls of a tritium distillation system; for this matter paper chromatography and high voltage electrophoresis techniques were used. Lithium aluminate was synthetized, being characterized as LiAlO 2 which was irradiated with neutrons in order to produce fluorine-18. Lithium aluminate is a non-soluble solid, therefore fluorine produced may not be extracted, unless it is dissolved or extracted through the solid. So as not affect in a drastic way the chemical form, it was submitted to extraction processes, agitating the irradiated samples with different acids and basic solutions in order to analyze fluorine-18. The best extraction agent was found to be HCl, where two forms of fluorine-18 were found, one at the point of application, probably as a complex hexafluoride-aluminate and the other as a characteristic Rf of the fluorine ion. In the tritium distillation with helium as a carrier of a sample irradiated and heated up to 220-250 o C, no volatile types of fluorine-18 were found, thus it can be considered that in commercial production of tritium by means of neutron irradiation of lithium aluminate, fluorine-18 is not a damaging pollutant of the equipment pipe system. (Author)

  3. Modeling the partitioning of organic chemical species in cloud phases with CLEPS (1.1)

    Science.gov (United States)

    Rose, Clémence; Chaumerliac, Nadine; Deguillaume, Laurent; Perroux, Hélène; Mouchel-Vallon, Camille; Leriche, Maud; Patryl, Luc; Armand, Patrick

    2018-02-01

    The new detailed aqueous-phase mechanism Cloud Explicit Physico-chemical Scheme (CLEPS 1.0), which describes the oxidation of isoprene-derived water-soluble organic compounds, is coupled with a warm microphysical module simulating the activation of aerosol particles into cloud droplets. CLEPS 1.0 was then extended to CLEPS 1.1 to include the chemistry of the newly added dicarboxylic acids dissolved from the particulate phase. The resulting coupled model allows the prediction of the aqueous-phase concentrations of chemical compounds originating from particle scavenging, mass transfer from the gas-phase and in-cloud aqueous chemical reactivity. The aim of the present study was more particularly to investigate the effect of particle scavenging on cloud chemistry. Several simulations were performed to assess the influence of various parameters on model predictions and to interpret long-term measurements conducted at the top of Puy de Dôme (PUY, France) in marine air masses. Specific attention was paid to carboxylic acids, whose predicted concentrations are on average in the lower range of the observations, with the exception of formic acid, which is rather overestimated in the model. The different sensitivity runs highlight the fact that formic and acetic acids mainly originate from the gas phase and have highly variable aqueous-phase reactivity depending on the cloud acidity, whereas C3-C4 carboxylic acids mainly originate from the particulate phase and are supersaturated in the cloud.

  4. Surrogate Motherhood II: Reflections after "Baby M."

    Science.gov (United States)

    Schwartz, Lita Linzer

    1988-01-01

    Discusses the "Baby M" surrogate motherhood case which has produced heated debate in popular media, legal publications, and other professional journals. Summarizes arguments offered and reasoning behind actions of judiciary. (Author/ABL)

  5. Chemically emulsified crude oil as substrate for bacterial oxidation : differences in species response

    International Nuclear Information System (INIS)

    Bruheim, P.; Eimhjellen, K.

    1998-01-01

    The ability of bacterial species to oxidize alkanes in crude oil in water emulsions was studied. Alkanes in crude oil need specific physiological adaptations to the microorganisms. Synthesis of biosurfactants has been considered as a prerequisite for either specific adhesion mechanisms to large oil drops or emulsification of oil followed by uptake of submicron oil droplets. In this study four bacterial species were tested. Emulsions were prepared by nonionic sorbitan ester and polyoxyethylene ether surfactants. The oxidation rates were measured. Both positive and negative effects of surfactant amendments were observed. The same surfactant affected different bacteria in different ways. The response to the surfactant amendment depended on the physiological state of the bacteria. The results showed that surfactants resulted in decreased cell adhesion to the oil phase for all the bacteria. 19 refs., 3 tabs., 4 figs

  6. Antimicrobial activity and chemical constituents of essential oils and oleoresins extracted from eight pepper species

    Directory of Open Access Journals (Sweden)

    Laira Martinelli

    Full Text Available ABSTRACT: Essential oils are the most important compounds produced during secondary metabolism in aromatic plants. Essential oils are volatile, have characteristic odor and are used as defensive agents by plants. In pepper, it is possible to say that essential oils are the “flavor fingerprint” of each species. In the present article, eight species of pepper were studied in order to extract their essential oils and oleoresins, test their antibacterial and antifungal activities and also to identify the compounds present in the most bioactive samples. Results demonstrated that two essential oils [Pimenta dioica (L. Merr. and Schinus terebinthifolius] and three oleoresins (Schinus terebinthifolius and Piper nigrum white and black recorded significant antimicrobial activity. These active essential oils and oleoresins are interesting for use in biotechnological processes employed in food, pharmaceutical and other industries.

  7. A High Throughput Ambient Mass Spectrometric Approach to Species Identification and Classification from Chemical Fingerprint Signatures

    OpenAIRE

    Musah, Rabi A.; Espinoza, Edgard O.; Cody, Robert B.; Lesiak, Ashton D.; Christensen, Earl D.; Moore, Hannah E.; Maleknia, Simin; Drijfhout, Falko P.

    2015-01-01

    A high throughput method for species identification and classification through chemometric processing of direct analysis in real time (DART) mass spectrometry-derived fingerprint signatures has been developed. The method entails introduction of samples to the open air space between the DART ion source and the mass spectrometer inlet, with the entire observed mass spectral fingerprint subjected to unsupervised hierarchical clustering processing. A range of both polar and non-polar chemotypes a...

  8. Portuguese Thymbra and Thymus species volatiles: chemical composition and biological activities.

    Science.gov (United States)

    Figueiredo, A C; Barroso, J G; Pedro, L G; Salgueiro, L; Miguel, M G; Faleiro, M L

    2008-01-01

    Thymbra capitata and Thymus species are commonly known in Portugal as thyme and they are currently used as culinary herbs, as well as for ornamental, aromatizing and traditional medicinal purposes. The present work reports on the state of the art on the information available on the taxonomy, ethnobotany, cell and molecular biology of the Portuguese representatives of these genera and on the chemotaxonomy and antibacterial, antifungal and antioxidant activities of their essential oils and other volatile-containing extracts.

  9. CHEMICAL RISKS TO THREATENED AND ENDANGERED FISH SPECIES AT CONCENTRATIONS BELOW WATER QUALITY CRITERIA: IS IT FEASIBLE TO ENSURE PROTECTION OF INDIVIDUALS

    Science.gov (United States)

    The USGS Laboratory in Columbia, Missouri has evaluated the acute sensitivities of 17 threatened and endangered fish species (including three salmonids), to five different chemicals (carbaryl, copper, 4-nonylphenol, pentachlorophenol, and permethrin). The results of these studie...

  10. Surrogate versus couple therapy in vaginismus.

    Science.gov (United States)

    Ben-Zion, Itzhak; Rothschild, Shelly; Chudakov, Bella; Aloni, Ronit

    2007-05-01

    Women who do not have a cooperative partner cannot complete the usual therapeutic process in the treatment of vaginismus, because they cannot progress to the stage of practicing the insertion of the man partner's fingers and the insertion of a penis. To compare traditional couple therapy with therapy utilizing a surrogate partner. The study was controlled and retrospective. Data were obtained from the treatment charts of patients who had come to the clinic for treatment of vaginismus. Sixteen vaginismus patients who were treated with a man surrogate partner were compared with 16 vaginismus patients who were treated with their own partners. Successful pain-free intercourse upon completion of therapy. One hundred percent of the surrogate patients succeeded in penile-vaginal intercourse compared with 75% in the couples group (P = 0.1). All surrogate patients ended the therapy because it was fully successful, compared with 69% in the couples group. Twelve percent of the couples group ended the therapy because it failed, and 19% because the couples decided to separate. Treating vaginismus with a man surrogate partner was at least as effective as couple therapy. Surrogate therapy may be considered for vaginismus patients who have no cooperative partner.

  11. Chemical constituents variations of essential oils from rhizomes of four Zingiberaceae species

    International Nuclear Information System (INIS)

    Sukari, M.A.; Mohd Sharif, N.W.; Yap, A.L.C.; Tang, S.W.; Rahmani, M.; Ee, G.C.L.; Taufiq-Yap, Y.H.; Yusof, U.K.

    2008-01-01

    The essential oils were extracted using the hydrodistillation method from four Zingiberaceae species; Zingiber officinale var.rubrum, Zingiber amaricans, Kaempferia galanga, and Boesenbergia pandurata. Volatile components of all extracts were analyzed by gas chromatography-mass spectrometry (GC-MS) techniques. The major constituents of Zingiber officinale, Zingiber amaricans, Kaempferia galanga, and Boesenbergia pandurata were identified as E-citral (20.98%), zerumbone (40.70%), ethyl p -methoxycinnamate (58.47%) and camphor (57.97%), respectively. Kaempferia galanga and Zingiber amaricans were rich in sesquiterpenes whereas Boesenbergia pandurata and Zingiber officinale var. rubrum contained mostly monoterpenes. (author)

  12. Welding fumes from stainless steel gas metal arc processes contain multiple manganese chemical species.

    Science.gov (United States)

    Keane, Michael; Stone, Samuel; Chen, Bean

    2010-05-01

    Fumes from a group of gas metal arc welding (GMAW) processes used on stainless steel were generated using three different metal transfer modes and four different shield gases. The objective was to identify and measure manganese (Mn) species in the fumes, and identify processes that are minimal generators of Mn species. The robotic welding system was operated in short-circuit (SC) mode (Ar/CO2 and He/Ar), axial spray (AXS) mode (Ar/O2 and Ar/CO2), and pulsed axial-spray (PAXS) mode (Ar/O2). The fumes were analyzed for Mn by a sequential extraction process followed by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) analysis, and by X-ray diffraction (XRD). Total elemental Mn, iron (Fe), chromium (Cr) and nickel (Ni) were separately measured after aqua regia digestion and ICP-AES analysis. Soluble Mn2+, Fe2+, Fe3+, and Ni2+ in a simple biological buffer (phosphate-buffered saline) were determined at pH 7.2 and 5.0 after 2 h incubation at 37 C by ion chromatography. Results indicate that Mn was present in soluble form, acid-soluble form, and acid-soluble form after reduction by hydroxylamine, which represents soluble Mn0 and Mn2+ compounds, other Mn2+ compounds, and (Mn3+ and Mn4+) compounds, respectively. The dominant fraction was the acid-soluble Mn2+ fraction, but results varied with the process and shield gas. Soluble Mn mass percent in the fume ranged from 0.2 to 0.9%, acid-soluble Mn2+ compounds ranged from 2.6 to 9.3%, and acid plus reducing agent-soluble (Mn3+ and Mn4+) compounds ranged from 0.6 to 5.1%. Total Mn composition ranged from 7 to 15%. XRD results showed fumes had a crystalline content of 90-99% Fe3O4, and showed evidence of multiple Mn oxides, but overlaps and weak signals limited identification. Small amounts of the Mn2+ in the fume (welding process. Mn generation rates for the fractions were tabulated, and the influence of ozone is discussed. The conclusions are that exposures to welding fumes include multiple Mn species, both

  13. Chemical Characterization and Antioxidant Potential of Wild Ganoderma Species from Ghana.

    Science.gov (United States)

    Obodai, Mary; Mensah, Deborah L Narh; Fernandes, Ângela; Kortei, Nii Korley; Dzomeku, Matilda; Teegarden, Matthew; Schwartz, Steven J; Barros, Lillian; Prempeh, Juanita; Takli, Richard K; Ferreira, Isabel C F R

    2017-01-25

    The chemical characterization and antioxidant potential of twelve wild strains of Ganoderma sp. from Ghana, nine (LS1-LS9) of which were found growing wild simultaneously on the same dying Delonix regia tree, were evaluated. Parameters evaluated included the nutritional value, composition in sugars, fatty acids, phenolic and other organic compounds and some vitamins and vitamin precursors. Antioxidant potential was evaluated by investigating reducing power, radical scavenging activity and lipid peroxidation inhibition using five in vitro assays. Protein, carbohydrate, fat, ash and energy contents ranged between 15.7-24.5 g/100 g·dw, 73.31-81.90 g/100 g, 0.48-1.40 g/100 g, 0.68-2.12 g/100 g ash and 396.1-402.02 kcal/100 g, respectively. Fatty acids such as linoleic, oleic and palmitic acids were relatively abundant. Free sugars included rhamnose, fructose, mannitol, sucrose and trehalose. Total tocopherols, organic acids and phenolic compounds' content ranged between 741-3191 µg/100 g, 77-1003 mg/100 g and 7.6-489 µg/100 g, respectively. There were variations in the β-glucans, ergosterol and vitamin D₂ contents. The three major minerals in decreasing order were K > P > S. Ganoderma sp. strain AM1 showed the highest antioxidant activity. This study reveals, for the first time, chemical characteristics of Ganoderma spp. which grew simultaneously on the same tree.

  14. Chemical Composition of Essential Oils of Xanthium spinosum L., an Invasive Species of Corsica.

    Science.gov (United States)

    Andreani, Stéphane; Paolini, Julien; Costa, Jean; Muselli, Alain

    2017-01-01

    Xanthium spinosum L. is a highly invasive plant originated from South America throughout the world as well as in Corsica Island. The chemical composition of X. spinosum essential oils from 25 Corsican locations was investigated using GC-FID and GC/MS. Seventy-four components, which accounted for 96.2% of the total amount, were reported for the first time in the essential oil from aerial parts. The main compounds were eudesma-4(14),7-dien-1β-ol (61; 21.3%), germacrene D (36; 8.8%) and cadalene (60; 8.7%). Comparison with the literature highlighted the originality of the Corsican essential oil and eudesma-4(14),7-dien-1β-ol could be used as taxonomical marker to the systematics of the Xanthium genus. The essential oils obtained from separate organs and during the plant vegetative cycle were also studied to gain more knowledge about the correlations between the volatile production and the phenological states of this weed. The production of oxygenated sesquiterpenes was predominant during the plant-flowering process. The study focuses on direct correlation between the chemical composition of individual 25 oil samples and the morphological differences of the plant. Our results have gained more knowledge about the secondary metabolite production that occurs during the plant life, they could be interesting in order to manage the dispersal of X. spinosum. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  15. IMPACT OF WOODY PLANTS SPECIES ON SOIL PHYSIO-CHEMICAL PROPERTIES ALONG GRAZING GRADIENTS IN RANGELANDS OF EASTERN ETHIOPIA

    Directory of Open Access Journals (Sweden)

    Mohammed Mussa Abdulahi

    2016-12-01

    Full Text Available In the lowlands of arid and semiarid rangelands woody plants plays an important role in soil fertility maintenance, providing food, medicine, cosmetics, fodder, fuel wood and pesticides. A better understanding of the interaction of woody plants on their immediate environment is needed to guide optimum management of native vegetation in the production landscapes. However, the impact of woody plant species on soil properties remains poorly understood. This study evaluates the impact of two dominant woody plant species (A. senegal and B. aegyptica on soil physico-chemical properties along grazing gradients in rangelands of eastern Ethiopia. Six trees of each species were selected from light, moderate and heavy grazing sites.  Soil sample data at two depths (0-15 and 16-30 cm were collected from under and open areas of A. senegal and B. aegyptica from each grazing sites, and analysed for nutrient contents. The nutrient status of soil under both woody species was significantly higher especially with regard to soil organic matter (4.37%, total nitrogen (0.313%, and available phosphorus (11.62 than the open grassland with soil organic matter (3.82%, total nitrogen (0.246%, and available phosphorus (10.94 mg/Kg soil for A. Senegal. The soil organic matter (3.93%, total nitrogen (0.285%, available phosphorus (11.66 mg/Kg soil were significantly higher than open grassland with soil organic matter (3.52%, total nitrogen (0.218%, available phosphorus (10.73 mg/Kg soil for B. aegyptica. This was more pronounced in the top 15 cm of soil under A. senegal woody plant species and on the light and moderate grazing site. Therefore, this tree has a significant effect on soil fertility improvement in resource poor rangelands and as a result, it is important to retain scattered A. senegal and B. aegyptica plants in the lowlands of eastern Ethiopia.

  16. The Atmospheric Tomography Mission (ATom): Comparing the Chemical Climatology of Reactive Species and Air Parcels from Measurements and Global Models

    Science.gov (United States)

    Prather, M. J.; Flynn, C.; Wennberg, P. O.; Kim, M. J.; Ryerson, T. B.; Hanisco, T. F.; Diskin, G. S.; Daube, B. C.; Commane, R.; McKain, K.; Apel, E. C.; Blake, N. J.; Blake, D. R.; Elkins, J. W.; Hall, S.; Steenrod, S.; Strahan, S. E.; Lamarque, J. F.; Fiore, A. M.; Horowitz, L. W.; Murray, L. T.; Mao, J.; Shindell, D. T.; Wofsy, S. C.

    2017-12-01

    The NASA Atmospheric Tomography Mission (ATom) is building a photochemical climatology of the remote troposphere based on objective sampling and profiling transects over the Pacific and Atlantic Oceans. These statistics provide direct tests of chemistry-climate models. The choice of species focuses on those controlling primary reactivity (a.k.a. oxidative state) of the troposphere, specifically chemical tendencies of O3 and CH4. These key species include, inter alia, O3, CH4, CO, C2H6, other alkanes, alkenes, aromatics, NOx, HNO3, HO2NO2, PAN, other organic nitrates, H2O, HCHO, H2O2, CH3OOH. Three of the four ATom deployments are now complete, and data from the first two (ATom-1 & -2) have been released as of this talk (see espoarchive.nasa.gov/archive/browse/atom). The statistical distributions of key species are presented as 1D and 2D probability densities (PDs) and we focus here on the tropical and mid-latitude regions of the Pacific during ATom-1 (Aug) and -2 (Feb). PDs are computed from ATom observations and 6 global chemistry models over the tropospheric depth (0-12 km) and longitudinal extent of the observations. All data are weighted to achieve equal mass-weighting by latitude regimes to account for spatial sampling biases. The models are used to calculate the reactivity in each ATom air parcel. Reweighting parcels with loss of CH4 or production of O3, for example, allows us to identify which air parcels are most influential, including assessment of the importance of fine pollution layers in the most remote troposphere. Another photochemical climatology developed from ATom, and used to test models, includes the effect of clouds on photolysis rates. The PDs and reactivity-weighted PDs reveal important seasonal differences and similarities between the two campaigns and also show which species may be most important in controlling reactivities. They clearly identify some very specific failings in the modeled climatologies and help us evaluate the chemical

  17. Chromatographic speciation of Cr(III)-species, inter-species equilibrium isotope fractionation and improved chemical purification strategies for high-precision isotope analysis.

    Science.gov (United States)

    Larsen, K K; Wielandt, D; Schiller, M; Bizzarro, M

    2016-04-22

    Chromatographic purification of chromium (Cr), which is required for high-precision isotope analysis, is complicated by the presence of multiple Cr-species with different effective charges in the acid digested sample aliquots. The differing ion exchange selectivity and sluggish reaction rates of these species can result in incomplete Cr recovery during chromatographic purification. Because of large mass-dependent inter-species isotope fractionation, incomplete recovery can affect the accuracy of high-precision Cr isotope analysis. Here, we demonstrate widely differing cation distribution coefficients of Cr(III)-species (Cr(3+), CrCl(2+) and CrCl2(+)) with equilibrium mass-dependent isotope fractionation spanning a range of ∼1‰/amu and consistent with theory. The heaviest isotopes partition into Cr(3+), intermediates in CrCl(2+) and the lightest in CrCl2(+)/CrCl3°. Thus, for a typical reported loss of ∼25% Cr (in the form of Cr(3+)) through chromatographic purification, this translates into 185 ppm/amu offset in the stable Cr isotope ratio of the residual sample. Depending on the validity of the mass-bias correction during isotope analysis, this further results in artificial mass-independent effects in the mass-bias corrected (53)Cr/(52)Cr (μ(53)Cr* of 5.2 ppm) and (54)Cr/(52)Cr (μ(54)Cr* of 13.5 ppm) components used to infer chronometric and nucleosynthetic information in meteorites. To mitigate these fractionation effects, we developed strategic chemical sample pre-treatment procedures that ensure high and reproducible Cr recovery. This is achieved either through 1) effective promotion of Cr(3+) by >5 days exposure to HNO3H2O2 solutions at room temperature, resulting in >∼98% Cr recovery for most types of sample matrices tested using a cationic chromatographic retention strategy, or 2) formation of Cr(III)-Cl complexes through exposure to concentrated HCl at high temperature (>120 °C) for several hours, resulting in >97.5% Cr recovery using a

  18. A reaction mechanism for gasoline surrogate fuels for large polycyclic aromatic hydrocarbons

    KAUST Repository

    Raj, Abhijeet

    2012-02-01

    This work aims to develop a reaction mechanism for gasoline surrogate fuels (n-heptane, iso-octane and toluene) with an emphasis on the formation of large polycyclic aromatic hydrocarbons (PAHs). Starting from an existing base mechanism for gasoline surrogate fuels with the largest chemical species being pyrene (C 16H 10), this new mechanism is generated by adding PAH sub-mechanisms to account for the formation and growth of PAHs up to coronene (C 24H 12). The density functional theory (DFT) and the transition state theory (TST) have been adopted to evaluate the rate constants for several PAH reactions. The mechanism is validated in the premixed laminar flames of n-heptane, iso-octane, benzene and ethylene. The characteristics of PAH formation in the counterflow diffusion flames of iso-octane/toluene and n-heptane/toluene mixtures have also been tested for both the soot formation and soot formation/oxidation flame conditions. The predictions of the concentrations of large PAHs in the premixed flames having available experimental data are significantly improved with the new mechanism as compared to the base mechanism. The major pathways for the formation of large PAHs are identified. The test of the counterflow diffusion flames successfully predicts the PAH behavior exhibiting a synergistic effect observed experimentally for the mixture fuels, irrespective of the type of flame (soot formation flame or soot formation/oxidation flame). The reactions that lead to this synergistic effect in PAH formation are identified through the rate-of-production analysis. © 2011 The Combustion Institute.

  19. Chemical composition of particles from traditional burning of Pakistani wood species

    Science.gov (United States)

    Shahid, Imran; Kistler, Magdalena; Mukhtar, Azam; Ramirez-Santa Cruz, Carlos; Bauer, Heidi; Puxbaum, Hans

    2015-11-01

    Total particulate matter (TPM) emitted during burning of three types of Pakistani wood (eucalyptus camaldulensis, local name Safeeda; acacia nilotica, local name Kikar, Babul; dalbergia sissoo, Shisham, Tali) in a traditional brick stove were collected and analyzed for anhydrosugars, sugar alcohols, trace metals, soluble ions and carbonaceous species. This is a first study reporting anhydrosugars in wood smoke particles emitted during traditional burning of common wood types in Pakistan. Carbonaceous species showed the highest contribution to the particulate matter. Although the total carbon (TC) contribution was similar for all burnings (64.8-70.2%), the EC/OC ratio varied significantly, from 0.2 to 0.3 for Accacia and Dalbergia to 0.7-0.8 for Eucalyptus and Wood-mix. Among inorganic constituents potassium chloride and silicon were found at levels higher than 1%. The levoglucosan concentrations ranged from 3.0 to 6.6% (average 5.6%) with the highest value for Accacia and lowest value for the wood-mix. The high levoglucosan/mannosan ratios of 20-28 were typical for hardwood. The ratio between levoglucosan and galactosan varied stronger and was found to be around 13-20 for Accacia, Eucalyptus and Wood mix, and 43 for Dalbergia. The determined levoglucosan concentrations allowed assessing the conversion factor for calculation of biomass smoke contribution to ambient particulate matter levels in Pakistan.

  20. Natural Chemical Composition of Commercial Fish Species: Characterisation of Pangasius, Wild and Farmed Turbot and Barramundi

    Science.gov (United States)

    Manthey-Karl, Monika; Lehmann, Ines; Ostermeyer, Ute; Schröder, Ute

    2016-01-01

    To comply with the relevant legal requirements and correct labelling, it is necessary for business operators and inspection authorities to know the natural characteristics of the raw material. This study gives a comprehensive overview of muscle flesh composition of farmed and wild Atlantic turbot (Scophthalmus maximus) and barramundi (Lates calcarifer) and of farmed pangasius (Pangasianodon hypophthalmus). The proximate composition, di- and triphosphates and citric acid values are presented in order to evaluate possible indicators for a hidden treatment during processing to fillets. All moisture contents were ≤80%. Even for pangasius, protein values for deep skinned fillets of ≥18% were determined. Only small quantities of naturally occurring citric acid (up to 0.03 g·kg−1) were detectable. The lipid content was the most varying main component within the different species, ranging between 1.2% to 2.0% and 0.3% to 3.0% for farmed turbot and barramundi, respectively. Pangasius flesh had a mean lipid content of 7.8%. Trimming and separation of the red layer reduced the lipid content of the commercially sold white-flesh fillets to 2.7% to 3.5%. Fatty acids profiles, free amino acids, and minerals were analysed to show the nutritional quality of the aquaculture fish species and compared to wild turbot and barramundi. Despite some natural variation, these components can be considered as comparable. PMID:28231154

  1. Chemical and Biological Analyses of the Essential Oils and Main Constituents of Piper Species

    Directory of Open Access Journals (Sweden)

    Leonor Laura Leon

    2012-02-01

    Full Text Available The essential oils obtained from leaves of Piper duckei and Piper demeraranum by hydrodistillation were analyzed by gas chromatography-mass spectrometry. The main constituents found in P. demeraranum oil were limonene (19.3% and β-elemene (33.1% and in P. duckei oil the major components found were germacrene D (14.7% and trans-caryophyllene (27.1%. P. demeraranum and P. duckei oils exhibited biological activity, with IC50 values between 15 to 76 μg mL−1 against two Leishmania species, P. duckei oil being the most active. The cytotoxicity of the essential oils on mice peritoneal macrophage cells was insignificant, compared with the toxicity of pentamidine. The main mono- and sesquiterpene, limonene (IC50 = 278 μM and caryophyllene (IC50 = 96 μM, were tested against the strains of Leishmania amazonensis, and the IC50 values of these compounds were lower than those found for the essential oils of the Piper species. The HET-CAM test was used to evaluate the irritation potential of these oils as topical products, showing that these oils can be used as auxiliary medication in cases of cutaneous leishmaniasis, with less side effects and lower costs.

  2. Natural Chemical Composition of Commercial Fish Species: Characterisation of Pangasius, Wild and Farmed Turbot and Barramundi

    Directory of Open Access Journals (Sweden)

    Monika Manthey-Karl

    2016-08-01

    Full Text Available To comply with the relevant legal requirements and correct labelling, it is necessary for business operators and inspection authorities to know the natural characteristics of the raw material. This study gives a comprehensive overview of muscle flesh composition of farmed and wild Atlantic turbot (Scophthalmus maximus and barramundi (Lates calcarifer and of farmed pangasius (Pangasianodon hypophthalmus. The proximate composition, di- and triphosphates and citric acid values are presented in order to evaluate possible indicators for a hidden treatment during processing to fillets. All moisture contents were ≤80%. Even for pangasius, protein values for deep skinned fillets of ≥18% were determined. Only small quantities of naturally occurring citric acid (up to 0.03 g·kg−1 were detectable. The lipid content was the most varying main component within the different species, ranging between 1.2% to 2.0% and 0.3% to 3.0% for farmed turbot and barramundi, respectively. Pangasius flesh had a mean lipid content of 7.8%. Trimming and separation of the red layer reduced the lipid content of the commercially sold white-flesh fillets to 2.7% to 3.5%. Fatty acids profiles, free amino acids, and minerals were analysed to show the nutritional quality of the aquaculture fish species and compared to wild turbot and barramundi. Despite some natural variation, these components can be considered as comparable.

  3. Screening of Chemical Composition, Antioxidant and Anticholinesterase Activity of Section Brevifilamentum of Origanum (L. Species

    Directory of Open Access Journals (Sweden)

    Hasibe Yılmaz

    2017-09-01

    Full Text Available Six Origanum species, Origanum acutidens (Hand. -Mazz. Ietsw. (OA, Origanum brevidens (Bornm. Dinsm. (OB, Origanum haussknechtii Boiss. (OC, Origanum husnucan-baseri H.Duman, Aytaç & A.Duran (OHB, Origanum leptocladum Boiss. (OL, Origanum rotundifolium Boiss. (OR, belonging to sect. Brevifilamentum were analyzed for their essential oil and phenolic components. For the essential oil analyses, GC-MS and GC-FID were used. Phenolic contents of the aerial parts of the chloroform, acetone, and methanol extracts were analyzed using LC-MS/MS. Antioxidant activity of the species was investigated by three methods; DPPH free radical scavenging activity, β-carotene linoleic acid assays and CUPRAC assays. Also, acetyl and butyrylcholinesterase inhibition of the extracts were investigated. While the essential oil contents of the section Brevifilamentum showed difference in chemotype, the phenolic contents were found to be coumaric acids and derivatives. These groups were the most abundant components of the extracts. Especially rosmarinic acid was detected in high amounts in acetone and methanol extracts. OA had the best activity both in antioxidant and anticholinesterase assays.

  4. Species delimitation and evolution in morphologically and chemically diverse communities of the lichen-forming genus Xanthoparmelia (Parmeliaceae, Ascomycota) in western North America.

    Science.gov (United States)

    Leavitt, Steven D; Johnson, Leigh; St Clair, Larry L

    2011-02-01

    Accurate species delimitation is important for understanding the diversification of biota and has critical implications for ecological and conservation studies. However, a growing body of evidence indicates that morphology-based species circumspection in lichenized fungi misrepresents fungal diversity. The foliose lichen genus Xanthoparmelia includes over 800 species displaying a complex array of morphological and secondary metabolite diversity. We used a multifaceted approach, applying phylogenetic, population genetic, and genealogical analyses to delimit species in a single well-supported monophyletic clade containing 10 morphologically and chemically diverse Xanthoparmelia species in western North America. Sequence data from four ribosomal and two low-copy, protein-coding markers, along with chemical and morphological data were used to assess species diversity. We found that traditionally circumscribed species are not supported by molecular data. Rather, all sampled taxa were better represented by three polymorphic population clusters. Our results suggest that secondary metabolite variation may have limited utility in diagnosing lineages within this group, while identified populations clusters did not reflect major phylogeographic or ecological patterns. In contrast to studies revealing previously undiscovered fungal lineages masked within lichen species circumscribed by traditional morphological and chemical concepts, the present study suggests that species diversity has been overestimated in the species-rich genus Xanthoparmelia.

  5. Influence of reactions heats on variation of radius, temperature, pressure and chemical species amounts within a single acoustic cavitation bubble.

    Science.gov (United States)

    Kerboua, Kaouther; Hamdaoui, Oualid

    2018-03-01

    The scientific interest toward the study of acoustic bubble is mainly explained by its practical benefit in providing a reactional media favorable to the rapid evolution of chemical mechanism. The evolution of this mechanism is related to the simultaneous and dependent variation of the volume, temperature and pressure within the bubble, retrieved by the resolution of a differential equations system, including among others the thermal balance. This last one is subject to different assumptions, some authors deem simply that the temperature varies adiabatically during the collapsing phase, without considering the reactions heat of the studied mechanism. This paper aims to evaluate the pertinence of neglecting reactions heats in the thermal balance, by analyzing their effect on the variation of radius, temperature, pressure and chemical species amounts. The results show that the introduction of reactions heats conducts to a decrease of the temperature, an increase of the pressure and a reduction of the bubble volume. As a consequence, this leads to a drop of the quantities of free radicals produced by the chemical mechanism evolving within the bubble. This paper also proved that the impact of the consideration of reactions heats is dependent of the frequency and the acoustic amplitude of the ultrasonic wave. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Chemical dissolution of spent fuel and cladding using complexed fluoride species

    International Nuclear Information System (INIS)

    Rance, P.J.W.; Freeman, G.A.; Mishin, V.; Issoupov, V.

    2001-01-01

    The dissolution of LWR fuel cladding using two fluoride ion donors, HBF 4 and K 2 ZrF 6 , in combination with nitric acid has been investigated as a potential reprocessing head-end process suitable for chemical decladding and fuel dissolution in a single process step. Maximum zirconium concentrations in the order of 0,75 to 1 molar have been achieved and dissolution found to continue to low F:Zr ratios albeit at ever decreasing rates. Dissolution rates of un-oxidised zirconium based fuel claddings are fast, whereas oxidised materials exhibit an induction period prior to dissolution. Data is presented relating to the rates of dissolution of cladding and UO 2 fuels under various conditions. (author)

  7. Chemical composition and biological activities of the essential oils from two Pereskia species grown in Brazil.

    Science.gov (United States)

    Souza, Lucéia Fatima; De Barros, Ingrid Bergman Inchausti; Mancini, Emilia; De Martino, Laura; Scandolera, Elia; De Feo, Vincenzo

    2014-12-01

    The chemical composition of the essential oils of Pereskia aculeata Mill. and P. grandifolia Haw. (Cactaceae), grown in Brazil, was studied by means of GC and GC-MS. In all, 37 compounds were identified, 30 for P. aculeata and 15 for P. grandifolia. Oxygenated diterpenes are the main constituents, both in the oil ofP. grandifolia (55.5%) and in that ofP. aculeata (29.4%). The essential oils were evaluated for their in vitro phytotoxic activity against germination and initial radicle growth of Raphanus sativus L., Sinapis arvensis L., and Phalaris canariensis L. seeds. The essential oil of P. grandifolia, at all doses tested, significantly inhibited the radicle elongation of R. sativus. Moreover, the antimicrobial activity of the essential oils was assayed against ten bacterial strains. The essential oils showed weak inhibitory activity against the Gram-positive pathogens.

  8. Future Needs and Recommendations in the Development of Species Sensitivity Distributions: Estimating Toxicity Thresholds for Aquatic Ecological Communities and Assessing Impacts of Chemical Exposures

    Science.gov (United States)

    A species sensitivity distribution (SSD) is a probability model of the variation of species sensitivities to a stressor, in particular chemical exposure. The SSD approach has been used as a decision support tool in environmental protection and management since the 1980s, and the ...

  9. New applications in EPA’s ECOTOX Knowledge System: Assimilating relative potencies of metals across chemical and biological species from literature-based toxicity effects data.

    Science.gov (United States)

    Toxicity of metals in field settings can vary widely among ionic chemical species and across biological receptors. Thus, a challenge often found in developing TRVs for the risk assessment of metals is identifying the most appropriate metal and biological species combinations for...

  10. Chemical Constituents and Structural Characterization of Polysaccharides from Four Typical Bamboo Species Leaves

    Directory of Open Access Journals (Sweden)

    Cheng-Zhang Wang

    2015-03-01

    Full Text Available In order to find bamboo leaves with high contents of bioactive polysaccharides, 32 samples were chosen to analyze their polysaccharide content by GC and sulfuric acid-anthrone colorimetric assays. Purified polysaccharides (BLPS were separated from the four varieties P. nigra (Lodd. Munro (PN, P. vivax McClure (PV, Chimonobambusa quadrangularis (Fenzi Makino (CQ, and P. bambussoides cv. Tanakae (PB by ultrasound extraction, solution precipitation, ion exchange resin, DEAE-52 and Sephadex G-100 chromatography. BLPS structural characterization was accomplished by HPLC-GPC, Fourier transform infra-red spectroscopy (FTIR and NaIO4-HIO4 oxidation reactions. The results showed that the total polysaccharides of the bamboo leaves in samples 1–32 ranged between 1.4% and 5.4%, Samples No. 29–No. 32 (PN, PV, CQ, and PB contained 2–3 fold more polysaccharides than No. 1~No. 28 among the 32 different species, particularly the content of galactose was in a range of 21.5%–34.1% for these four typical bamboo species leaves, which was also more than 2–3 fold higher than in No. 1–No. 28. Sugar analysis indicated that PN-PBLPS-1, PV-PBLPS-1, CQ-PBLPS-1 and PB-PBLPS-1 from the four varieties were homogeneous polysaccharides with molecular weights of 2.04 × 104, 1.15 × 104, 8.75 × 104 and 1.48 × 104 Da, respectively. PB-PBLPS-1 was a mixture of α-galactopyranose and β-d-glucopyranose linkages with α-(1→6 or β-(1→6glycosidic bonds, while PN-PBLPS-1, PV-PBLPS-1, and CQ-PBLPS-1 had α galactopyranose linkages with α-(1→6 glycosidic bonds.

  11. Investigating the Hydrolysis Reactions of a Chemical Warfare Agent Surrogate. A Systematic Study using 1H, 13C, 17O, 19F, 31P, and 35Cl NMR Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Alam, Todd M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wilson, Brendan W. [West Virginia Univ., Morgantown, WV (United States)

    2015-07-24

    During the summer of 2015, I participated in the DHS HS-STEM fellowship at Sandia National Laboratories (SNL, NM) under the supervision of Dr. Todd M. Alam in his Nuclear Magnetic Resonance (NMR) Spectroscopy research group. While with the group, my main project involved pursing various hydrolysis reactions with Diethyl Chlorophosphate (DECP), a surrogate for the agent Sarin (GB). Specifically, I performed different hydrolysis reactions, monitored and tracked the different phosphorous containing species using phosphorous (31P) NMR spectroscopy. With the data collected, I performed kinetics studies mapping the rates of DECP hydrolysis. I also used the NMR of different nuclei such as 1H, 13C, 17O, and 35Cl to help understand the complexity of the reactions that take place. Finally, my last task at SNL was to work with Insensitive Nuclei Enhanced by Polarization Transfer (INEPT) NMR Spectroscopy optimizing conditions for 19F- 31P filtering NMR experiments.

  12. Intra-/inter-laboratory validation study on reactive oxygen species assay for chemical photosafety evaluation using two different solar simulators.

    Science.gov (United States)

    Onoue, Satomi; Hosoi, Kazuhiro; Toda, Tsuguto; Takagi, Hironori; Osaki, Naoto; Matsumoto, Yasuhiro; Kawakami, Satoru; Wakuri, Shinobu; Iwase, Yumiko; Yamamoto, Toshinobu; Nakamura, Kazuichi; Ohno, Yasuo; Kojima, Hajime

    2014-06-01

    A previous multi-center validation study demonstrated high transferability and reliability of reactive oxygen species (ROS) assay for photosafety evaluation. The present validation study was undertaken to verify further the applicability of different solar simulators and assay performance. In 7 participating laboratories, 2 standards and 42 coded chemicals, including 23 phototoxins and 19 non-phototoxic drugs/chemicals, were assessed by the ROS assay using two different solar simulators (Atlas Suntest CPS series, 3 labs; and Seric SXL-2500V2, 4 labs). Irradiation conditions could be optimized using quinine and sulisobenzone as positive and negative standards to offer consistent assay outcomes. In both solar simulators, the intra- and inter-day precisions (coefficient of variation; CV) for quinine were found to be below 10%. The inter-laboratory CV for quinine averaged 15.4% (Atlas Suntest CPS) and 13.2% (Seric SXL-2500V2) for singlet oxygen and 17.0% (Atlas Suntest CPS) and 7.1% (Seric SXL-2500V2) for superoxide, suggesting high inter-laboratory reproducibility even though different solar simulators were employed for the ROS assay. In the ROS assay on 42 coded chemicals, some chemicals (ca. 19-29%) were unevaluable because of limited solubility and spectral interference. Although several false positives appeared with positive predictivity of ca. 76-92% (Atlas Suntest CPS) and ca. 75-84% (Seric SXL-2500V2), there were no false negative predictions in both solar simulators. A multi-center validation study on the ROS assay demonstrated satisfactory transferability, accuracy, precision, and predictivity, as well as the availability of other solar simulators. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Laminar Flame Speeds of Gasoline Surrogates Measured with the Flat Flame Method

    KAUST Repository

    Liao, Y.-H.; Roberts, William L.

    2016-01-01

    © 2016 American Chemical Society. The adiabatic, laminar flame speeds of gasoline surrogates at atmospheric pressure over a range of equivalence ratios of = 0.8-1.3 and unburned gas temperatures of 298-400 K are measured with the flat flame method

  14. Toxicity of proton-metal mixtures in the field: Linking stream macroinvertebrate species diversity to chemical speciation and bioavailability

    Energy Technology Data Exchange (ETDEWEB)

    Stockdale, Anthony [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Tipping, Edward, E-mail: et@ceh.ac.uk [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Lofts, Stephen [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Ormerod, Stephen J. [Catchment Research Group, Cardiff School of Biosciences, Cardiff University, Cardiff CF10 3US (United Kingdom); Clements, William H. [Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO 80523 (United States); Blust, Ronny [Ecophysiology, Biochemistry and Toxicology Group, Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium)

    2010-10-01

    Understanding metal and proton toxicity under field conditions requires consideration of the complex nature of chemicals in mixtures. Here, we demonstrate a novel method that relates streamwater concentrations of cationic metallic species and protons to a field ecological index of biodiversity. The model WHAM-F{sub TOX} postulates that cation binding sites of aquatic macroinvertebrates can be represented by the functional groups of natural organic matter (humic acid), as described by the Windermere Humic Aqueous Model (WHAM6), and supporting field evidence is presented. We define a toxicity function (F{sub TOX}) by summing the products: (amount of invertebrate-bound cation) x (cation-specific toxicity coefficient, {alpha}{sub i}). Species richness data for Ephemeroptera, Plecoptera and Trichoptera (EPT), are then described with a lower threshold of F{sub TOX}, below which all organisms are present and toxic effects are absent, and an upper threshold above which organisms are absent. Between the thresholds the number of species declines linearly with F{sub TOX}. We parameterised the model with chemistry and EPT data for low-order streamwaters affected by acid deposition and/or abandoned mines, representing a total of 412 sites across three continents. The fitting made use of quantile regression, to take into account reduced species richness caused by (unknown) factors other than cation toxicity. Parameters were derived for the four most common or abundant cations, with values of {alpha}{sub i} following the sequence (increasing toxicity) H{sup +} < Al < Zn < Cu. For waters affected mainly by H{sup +} and Al, F{sub TOX} shows a steady decline with increasing pH, crossing the lower threshold near to pH 7. Competition effects among cations mean that toxicity due to Cu and Zn is rare at lower pH values, and occurs mostly between pH 6 and 8.

  15. Chemical Species, Micromorphology, and XRD Fingerprint Analysis of Tibetan Medicine Zuotai Containing Mercury.

    Science.gov (United States)

    Li, Cen; Yang, Hongxia; Du, Yuzhi; Xiao, Yuancan; Zhandui; Sanglao; Wang, Zhang; Ladan, Duojie; Bi, Hongtao; Wei, Lixin

    2016-01-01

    Zuotai ( gTso thal ) is one of the famous drugs containing mercury in Tibetan medicine. However, little is known about the chemical substance basis of its pharmacodynamics and the intrinsic link of different samples sources so far. Given this, energy dispersive spectrometry of X-ray (EDX), scanning electron microscopy (SEM), atomic force microscopy (AFM), and powder X-ray diffraction (XRD) were used to assay the elements, micromorphology, and phase composition of nine Zuotai samples from different regions, respectively; the XRD fingerprint features of Zuotai were analyzed by multivariate statistical analysis. EDX result shows that Zuotai contains Hg, S, O, Fe, Al, Cu, and other elements. SEM and AFM observations suggest that Zuotai is a kind of ancient nanodrug. Its particles are mainly in the range of 100-800 nm, which commonly further aggregate into 1-30  μ m loosely amorphous particles. XRD test shows that β -HgS, S 8 , and α -HgS are its main phase compositions. XRD fingerprint analysis indicates that the similarity degrees of nine samples are very high, and the results of multivariate statistical analysis are broadly consistent with sample sources. The present research has revealed the physicochemical characteristics of Zuotai , and it would play a positive role in interpreting this mysterious Tibetan drug.

  16. Chemical Composition, Larvicidal and Cytotoxic Activities of the Essential Oils from two Bauhinia Species

    Directory of Open Access Journals (Sweden)

    Leôncio M. de Sousa

    2016-05-01

    Full Text Available The essential oils obtained by hydrodistilation from leaves of Bauhinia pulchella Benth. and Bauhinia ungulata L. were analysed by GC-FID and GC-MS. The major components of B. pulchella essential oil were identified as a -pinene (23.9%, caryophyllene oxide (22.4% and b -pinene (12.2%, while in the B. ungulata essential oil were caryophyllene oxide (23.0%, (E-caryophyllene (14.5% and a -copaene (7.2%. The essential oils were subsequently evaluated for their larvicidal and cytotoxic activities. Larval bioassay against Aedes aegypti of B. pulchella and B. ungulata essential oils showed LC 50 values of 105.9 ± 1.5 and 75.1 ± 2.8 m g/mL, respectively. The essential oils were evaluated against four human cancer cells lines: HL-60 (pro-myelocytic leukemia, MCF-7 (breast adenocarcinoma, NCI-H292 (lung carcinoma and HEP-2 ( cervical adenocarcinoma, showing IC 50 values in the range of 9.9 to 53.1 m g/mL. This is the first report on chemical composition of essential from leaves of B. pulchella and on larvicidal and cytotoxic activities of the essential oils.

  17. Chemical Composition and Biological Activities of the Essential Oils from Three Melaleuca Species Grown in Tunisia

    Directory of Open Access Journals (Sweden)

    Ismail Amri

    2012-12-01

    Full Text Available The chemical composition of the essential oils of Melaleuca armillaris Sm., Melaleuca styphelioides Sm. and Melaleuca acuminata F. Muell., collected in Tunisia, was studied by means of GC and GC-MS analysis. In all, 46 compounds were identified, 38 for M. armillaris, 20 for M. acuminata and eight for M. styphelioides, respectively. The presence of a sesquiterpenic fraction (52.2% characterized the oil from M. armillaris; M. sthypheliodes oil was rich in methyl eugenol, a phenolic compound (91.1%, while M. acuminata oil is mainly constituted by oxygenated monoterpenoids (95.6%. The essential oils were evaluated for their in vitro potentially phytotoxic activity against germination and initial radicle growth of Raphanus sativus L., Lepidium sativum L., Sinapis arvensis L., Triticum durum L. and Phalaris canariensis L. seeds. The radicle elongation of five seeds was inhibited at the highest doses tested, while germination of all seeds was not affected. Moreover, the essential oils showed low antimicrobial activity against eight selected microorganisms.

  18. Chemical composition and biological activities of the essential oils from three Melaleuca species grown in Tunisia.

    Science.gov (United States)

    Amri, Ismail; Mancini, Emilia; De Martino, Laura; Marandino, Aurelio; Lamia, Hamrouni; Mohsen, Hanana; Bassem, Jamoussi; Scognamiglio, Mariarosa; Reverchon, Ernesto; De Feo, Vincenzo

    2012-12-05

    The chemical composition of the essential oils of Melaleuca armillaris Sm., Melaleuca styphelioides Sm. and Melaleuca acuminata F. Muell., collected in Tunisia, was studied by means of GC and GC-MS analysis. In all, 46 compounds were identified, 38 for M. armillaris, 20 for M. acuminata and eight for M. styphelioides, respectively. The presence of a sesquiterpenic fraction (52.2%) characterized the oil from M. armillaris; M. sthypheliodes oil was rich in methyl eugenol, a phenolic compound (91.1%), while M. acuminata oil is mainly constituted by oxygenated monoterpenoids (95.6%). The essential oils were evaluated for their in vitro potentially phytotoxic activity against germination and initial radicle growth of Raphanus sativus L., Lepidium sativum L., Sinapis arvensis L., Triticum durum L. and Phalaris canariensis L. seeds. The radicle elongation of five seeds was inhibited at the highest doses tested, while germination of all seeds was not affected. Moreover, the essential oils showed low antimicrobial activity against eight selected microorganisms.

  19. Evolution of 222 Rn and chemical species related with eruptive processes of the Popocatepetl volcano

    International Nuclear Information System (INIS)

    Aranda Z, P.

    1998-01-01

    The study of the water quality for human consumption has always been great importance, considering the factors that can affect water quality as aquifers recharge and underground permeability. In this work, the behavior of three water springs related with the Popocatepetl volcano were studied within April 1997 and March 1998. The spring in Paso de Cortes in the municipality of Amecameca, State of Mexico, and the springs of Atlimeyaya and Axocopan in Atlixco, State of Puebla; the water of these last two springs is used for human consumption. The content of radon in water was determined by means of liquid scintillation, and a concentration of 1.22 Bq/l was found in the spring of Atlimeyaya, which represents 2 % of the maximum permissible level established by ICRP. A significant increase was observed in the Paso de Cortes spring in the month of July 1997. The content of radium, was determined by means of gamma spectrophotometry and small quantities of this element ( 2+ , Mg 2+ , K + , Na + , H C O 3 - , Cl - , S O 4 - 2 , Li, B, Sc, Ti, V, Rb, Sr and Ba, primarily, which did not show any significant variation with the change of seasons. No important variations in the concentration of radon, radium or for other volcanic activity related species were found in the entire study. (Author)

  20. Radioisotope ratios in characterizing the movement of different physical and chemical species through natural soils

    International Nuclear Information System (INIS)

    Robertson, D.E.; Perkins, R.W.

    1975-01-01

    Physicochemical characterization studies of reactor effluent water radionuclides at the Hanford N-Reactor are providing important information describing the mobility of radionuclides in freshwater environments. At N-Reactor, cooling water containing a wide spectrum of radionuclides in various physicochemical forms is discharged to a seepage trench located near the reactor. The effluent water migrates through a soil bank between the trench and the Columbia River, and a portion of the water emerges as seepage springs along the bank of the Columbia River near the reactor. The mobility of effluent water radionuclides during transport through the soil is greatly dependent upon the physicochemical forms of the radionuclides. Radionuclides in particulate and cationic forms are nearly quantitatively retained in the soil bank by sorption onto mineral phases; whereas, radionuclides in anionic and soluble nonionic forms are relatively mobile and are retained by the soil to a much lesser degree. Several radionuclides such as 60 Co, 103-106 Ru and 122-124-125 Sb are present in reactor effluent water partitioned among particulate, cationic, anionic and non-ionic species. However, as these radionuclides migrate through the woil bank their particulate and cationic forms are retained, and predominantly anionic and nonionic forms emerged in the seepage springs. Studies of the behavior of these radionuclides are providing data for assessing present rad-waste treatment processes and in improving future processes for reducing environmental releases of radionuclides from nuclear installations. (author)

  1. In vitro antiplasmodial activity, cytotoxicity and chemical profiles of sponge species of Cuban coasts.

    Science.gov (United States)

    Mendiola, Judith; Regalado, Erik L; Díaz-García, Alexis; Thomas, Olivier P; Fernández-Calienes, Aymé; Rodríguez, Hermis; Laguna, Abilio; Valdés, Olga

    2014-01-01

    Aqueous and organic fractions from the crude extracts of 17 sponge species collected at Boca de Calderas, Havana, Cuba were analysed. The organic fractions of Mycale laxissima, Clathria echinata and Agelas cerebrum exhibited values of concentrations causing 50% inhibition of in vitro growth of Plasmodium berghei (IC50) of 42.3 ± 5.1, 52 ± 9.7 and 60.3 ± 10.6 μg/mL, respectively, while their selectivity indexes for fibroblast cell lines were 9.45, 4.24 and 8.7, correspondingly. These fractions reduced parasitemia of infected Balb/c mice as well. Selective cytotoxicity indexes against tumour HeLa cells focused an interest on the aqueous fraction of M. laxissima (>7.12) and organic fractions of Polymastia nigra (5.95), A. cerebrum (5.48) and Niphates erecta (>4.2). Triterpenoids/steroids and alkaloids detected in the organic fractions of M. laxissima, C. echinata and A. cerebrum should be isolated for future investigation.

  2. Comparative study of the chemical composition of essential oils of five Tagetes species collected in Venezuela.

    Science.gov (United States)

    Armas, Kaylin; Rojas, Janne; Rojas, Luis; Morales, Antonio

    2012-09-01

    The leaves and inflorescences of five species of Tagetes, family Asteraceae, were collected from different locations in Mérida state, Venezuela, and their essential oils analyzed by GC and GC/MS. Several differences were observed in the composition of these oils, mainly regarding the major components, which for T. caracasana were trans-ocimenone (64.3%) and cis-tagetone (13.7%), and for T. erecta, piperitone (35.9%) and terpinolene (22.2%). High amounts of trans-anethole (87.5%) and estragole (10.7%) were observed in T. filifolia, while T. subulata essential oil contained terpinolene (26.0%), piperitenone (13.1%) and limonene (10.8%). For T. patula, two different oil samples were analyzed, leaves (TPL) and inflorescences (TPI). The TPL oil showed terpinolene (20.9%) and piperitenone (14.0%) as main components, while the TPI sample was composed mainly of beta-caryophyllene (23.7%), terpinolene (15.6%) and cis-beta-ocimene (15.5%).

  3. Synthesis of Formamide and Related Organic Species in the Interstellar Medium via Chemical Dynamics Simulations

    Science.gov (United States)

    Spezia, Riccardo; Jeanvoine, Yannick; Hase, William L.; Song, Kihyung; Largo, Antonio

    2016-08-01

    We show, by means of direct dynamics simulations, how it is possible to define possible reactants and mechanisms leading to the formation of formamide in the interstellar medium. In particular, different ion-molecule reactions in the gas phase were considered: NH3OH+, NH2OH{}2+, H2COH+, and NH4 + for the ions and NH2OH, H2CO, and NH3 for the partner neutrals. These calculations were combined with high level ab initio calculations to investigate possible further evolution of the products observed. In particular, for formamide, we propose that the NH2OH{}2+ + H2CO reaction can produce an isomer, NH2OCH{}2+, that, after dissociative recombination, can produce neutral formamide, which was observed in space. The direct dynamics do not pre-impose any reaction pathways and in other reactions, we did not observe the formation of formamide or any possible precursor. On the other hand, we obtained other interesting reactions, like the formation of NH2CH{}2+. Finally, some radiative association processes are proposed. All of the results obtained are discussed in light of the species observed in radioastronomy.

  4. Influence of chemical form, feeding regimen, and animal species on the gastrointestinal absorption of plutonium

    International Nuclear Information System (INIS)

    Bhattacharyya, M.H.; Larsen, R.P.; Cohen, N.; Ralston, L.G.; Oldham, R.D.; Moretti, E.S.; Ayres, L.

    1985-01-01

    We evaluated the effect of chemical form and feeding regimen on the gastrointestinal (GI) absorption of plutonium in adult mice at plutonium concentrations relevant to the establishment of drinking water standards. Mean fractional GI absorption values in fasted adult mice were: Pu(VI) bicarbonate, 15 x 10 -4 ; Pu(IV) bicarbonate, 20 x 10 -4 ; Pu(IV) nitrate (pH2), 17 x 10 -4 ; Pu(IV) citrate, 24 x 10 -4 ; and Pu(IV) polymer, 3 x 10 -4 . Values in fed adult mice were: Pu(VI) bicarbonate, 1.4 x 10 -4 ; Pu(IV) polymer, 0.3 x 10 -4 . Pu(VI) is the oxidation state in chlorinated drinking waters and Pu(IV) is the oxidation state in many untreated natural waters. To assess the validity of extrapolating data from mice to humans, we also determined the GI absorption of Pu(VI) bicarbonate in adult baboons with a dual-isotope method that does not require animal sacrifice. Fractional GI absorption values obtained by this method were 23 +- 10 x 10 -4 for fasted baboons (n=5) and 1.4 +- 0.9 x 10 -4 for fed baboons (n=3). We have so far validated this method in one baboon and are currently completing validation in two additional animals. At low plutonium concentrations, plutonium oxidation state [Pu(VI) vs Pu(IV)] and administration medium (bicarbonate vs nitrate vs citrate) had little effect on the GI absorption of plutonium in mice. Formation of Pu(IV) polymers and animal feeding decreased the GI absorption of plutonium 5- to 10-fold. The GI absorption of Pu(VI) bicarbonate in both fed and fasted adult baboons appeared to be the same as in fed and fasted adult mice, respectively. 17 refs., 2 tabs

  5. Near infra-red chemical species tomography of sprays of volatile hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Hindle, F.P.; Carey, S.J.; Ozanyan, K.B.; McCann, H. [Dept. of Electrical Engineering and Electronics, UMIST, Manchester (United Kingdom); Winterbone, D.E.; Clough, E. [Dept. of Mechanical, Aerospace and Mfg. Engineering, UMIST, Manchester (United Kingdom)

    2002-08-01

    We report an All-Opto-Electronic tomography system that is sensitive to hydrocarbon vapour distribution, or liquid spray distribution, with temporal resolution of over 3000 frames per second. A tomography system comprising 32 channels has been built and tested. For chemical sensitivity to saturated hydrocarbons, we exploit the principle of Near Infra-Red (NIR) absorption at 1700 nm relative to a reference wavelength, using laser diode sources whose technology is based on that of the communications industry. Images are obtained from a laboratory set-up incorporating both gaseous injection and a liquid Gasoline Direct Injection (GDI) system. The performance of a prototype system on a running GDI engine is reported. The difficulty in performing concentration measurements of the gaseous fuel within the liquid spray region is shown, and means to improve this performance are discussed. However, it has been found possible to image the liquid spray cone using attenuation of the reference beam. These images correlate well with other techniques [1]. (orig.) [German] Wir berichten ueber ein optoelektronisches Tomographiesystem zur Bestimmung der Verteilung von Kohlenwasserstoffdaempfen oder von Spraypartikeln, das eine hohe zeitliche Aufloesung von 3000 Aufnahmen pro Sekunde liefert. Ein System mit 32 Kanaelen wurde gebaut und getestet. Um Empfindichkeit auf gesaettigte Kohlenwasserstoffdaempfe zu erzielen, wurde die Absorption im Nahen Infrarot (NIR) bei 1700 nm, bezogen auf die bei einer Referenzwellen-laenge, genutzt. Laserdioden, deren Technologien auch in der Kommunikationstechnik Verwendung finden, kamen zum Einsatz. Von einem Laboraufbau wurden Bilder aufgenommen sowohl bei Injektion von Gas als auch bei Direkteinspritzung fluessigen Brennstoffs (GDI). Wir berichten ueber die Ergebnisse mit dem Prototyp-Messsystem an einem GDI-Motor. Es werden die Schwierigkeiten gezeigt, Messungen der Gaskonzentration innerhalb eines Spraypartikelbereichs durchzufuehren, und

  6. Glacier mass balance reconstruction by sublimation induced enrichment of chemical species on Cerro Tapado (Chilean Andes

    Directory of Open Access Journals (Sweden)

    P. Ginot

    2006-01-01

    Full Text Available A 36 m long ice core down to bedrock from the Cerro Tapado glacier (5536 m a.s.l, 30°08' S, 69°55' W was analyzed to reconstruct past climatic conditions for Northern Chile. Because of the marked seasonality in the precipitation (short wet winter and extended dry summer periods in this region, major snow ablation and related post-depositional processes occur on the glacier surface during summer periods. They include predominantly sublimation and dry deposition. Assuming that, like measured during the field campaign, the enrichment of chloride was always related to sublimation, the chemical record along the ice core may be applied to reconstruct the history of such secondary processes linked to the past climatic conditions over northern Chile. For the time period 1962–1999, a mean annual net accumulation of 316 mm water equivalent (weq and 327 mm weq loss by sublimation was deduced by this method. This corresponds to an initial total annual accumulation of 539 mm weq. The annual variability of the accumulation and sublimation is related with the Southern Oscillation Index (SOI: higher net-accumulation during El-Niño years and more sublimation during La Niña years. The deepest part of the ice record shows a time discontinuity; with an ice body deposited under different climatic conditions: 290 mm higher precipitation but with reduced seasonal distribution (+470 mm in winter and –180 mm in summer and –3°C lower mean annual temperature. Unfortunately, its age is unknown. The comparison with regional proxy data however let us conclude that the glacier buildup did most likely occur after the dry mid-Holocene.

  7. Top predators: hot or not? A call for systematic assessment of biodiversity surrogates

    NARCIS (Netherlands)

    Cabeza, M.; Arponen, A.; Teeffelen, van A.J.A.

    2008-01-01

    argue that top predators are justified conservation surrogates based on a case study where raptor presence is associated with high species richness of birds, butterflies and trees. 2. We question the methodology as well as the applicability of their results, and clarify differences between

  8. Black-footed ferrets and Siberian polecats as ecological surrogates and ecological equivalents

    Science.gov (United States)

    Biggins, D.E.; Hanebury, L.R.; Miller, B.J.; Powell, R.A.

    2011-01-01

    Ecologically equivalent species serve similar functions in different communities, and an ecological surrogate species can be used as a substitute for an equivalent species in a community. Siberian polecats (Mustela eversmanii) and black-footed ferrets (M. nigripes) have long been considered ecological equivalents. Polecats also have been used as investigational surrogates for black-footed ferrets, yet the similarities and differences between the 2 species are poorly understood. We contrasted activity patterns of radiotagged polecats and ferrets released onto ferret habitat. Ferrets tended to be nocturnal and most active after midnight. Polecats were not highly selective for any period of the day or night. Ferrets and polecats moved most during brightly moonlit nights. The diel activity pattern of ferrets was consistent with avoidance of coyotes (Canis latrans) and diurnal birds of prey. Similarly, polecat activity was consistent with avoidance of red foxes (Vulpes vulpes) in their natural range. Intraguild predation (including interference competition) is inferred as a selective force influencing behaviors of these mustelines. Examination of our data suggests that black-footed ferrets and Siberian polecats might be ecological equivalents but are not perfect surrogates. Nonetheless, polecats as surrogates for black-footed ferrets have provided critical insight needed, especially related to predation, to improve the success of ferret reintroductions. ?? 2011 American Society of Mammalogists.

  9. Practical use of chemical probes for reactive oxygen species produced in biological systems by {gamma}-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Min Hee; Moon, Yu Ran; Chung, Byung Yeoup; Kim, Jae-Sung [Radiation Research Division for Bio-technology, Korea Atomic Energy Research Institute, 1266 Sinjeong-dong, Jeongeup-si, Jeollabuk-do 580-185 (Korea, Republic of); Lee, Kang-Soo [Crop Production and Technology Major, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Cho, Jae-Young [Bio-environmental Science Major, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Kim, Jin-Hong [Radiation Research Division for Bio-technology, Korea Atomic Energy Research Institute, 1266 Sinjeong-dong, Jeongeup-si, Jeollabuk-do 580-185 (Korea, Republic of)], E-mail: jhongkim@kaeri.re.kr

    2009-05-15

    Application of chemical probes, for detection of reactive oxygen species (ROS), was tested during {gamma}-irradiation. The ethanol/{alpha}-(4-pyridyl-1-oxide)-N-tert-butylnitrone (4-POBN) and 3,3'-diaminobenzidine (DAB) were structurally stable enough to detect {sup {center_dot}}OH and H{sub 2}O{sub 2}, increasingly generated by {gamma}-irradiation up to 1000 Gy. Interestingly, the production rate of H{sub 2}O{sub 2}, but not {sup {center_dot}}OH, during {gamma}-irradiation, was significantly different between in vitro systems of lettuce and spinach. These results suggest that 4-POBN and DAB could be utilized as a semi-quantitative probe to quantify {sup {center_dot}}OH and H{sub 2}O{sub 2}, produced by {gamma}-irradiation up to 1000 Gy.

  10. Attitudes toward surrogate motherhood in Canada.

    Science.gov (United States)

    Krishnan, V

    1994-01-01

    The issue of surrogate motherhood captured worldwide attention with the Baby M case in the United States. Some medical practitioners now claim that the surrogate arrangement may be the answer for certain women who are unable to conceive children naturally. Feminist activists are highly critical about the issue. In her landmark book The Mother Machine, Corea (1985) called surrogates "breeders," women whose bodies are being used by men. Lawyers and ethicists debate whether surrogacy is baby selling or not, and religious fundamentalists have condemned any form of procreation outside the "normal" or "natural" form of sexual relations within a marriage. But what do Canadian women think about commercial surrogacy? Findings pertaining to this issue from the latest national fertility survey of 5,315 women in the reproductive ages of 18-49 are reported.

  11. Legal regulation of surrogate motherhood in Israel.

    Science.gov (United States)

    Frenkel, D A

    2001-01-01

    The Israeli Law on surrogate motherhood demands a preconception agreement to include payments to be made to the surrogate mother. Surrogacy arrangements with family members are forbidden. Commercial surrogacy is allowed and encouraged. The Law causes many problems. Validity of consent given by surrogate mothers is doubtful. Possible future psychological harm are ignored. There is a danger of "commodification" of children. Abusing women of low socio-economic status as breeding machines may be another outcome. No clear responsibility is imposed on the "intended parents" for an impaired child. The law ignores possibility of divorce or death of the "intended parents" before the child's birth. Splitting motherhood is another social problem that has to be dealt with. So far the sperm of the husband from the "intended parents" has to be used, but further steps may follow. It is not certain that a policy of "positive eugenics" will not develop.

  12. Sequential chemical treatment of radium species in TENORM waste sludge produced from oil and natural gas production

    International Nuclear Information System (INIS)

    El Afifi, E.M.; Awwad, N.S.; Hilal, M.A.

    2009-01-01

    This paper is dedicated to the treatment of sludge occurring in frame of the Egyptian produced from oil and gas production. The activity levels of three radium isotopes: Ra-226 (of U-series), Ra-228 and Ra-224 (of Th-series) in the solid TENORM waste (sludge) were first evaluated and followed by a sequential treatment for all radium species (fractions) presented in TENORM. The sequential treatment was carried out based on two approaches 'A' and 'B' using different chemical solutions. The results obtained indicate that the activity levels of all radium isotopes (Ra-226, Ra-228 and Ra-224) of the environmental interest in the TENORM waste sludge were elevated with regard to exemption levels established by IAEA [International Atomic Energy Agency (IAEA), International basic safety standards for the protection against ionizing radiation and for the safety of radiation sources. GOV/2715/Vienna, 1994]. Each approach of the sequential treatment was performed through four steps using different chemical solutions to reduce the activity concentration of radium in a large extent. Most of the leached radium was found as an oxidizable Ra species. The actual removal % leached using approach B was relatively efficient compared to A. It is observed that the actual removal percentages (%) of Ra-226, Ra-228 and Ra-224 using approach A are 78 ± 2.8, 64.8 ± 4.1 and 76.4 ± 5.2%, respectively. Whereas in approach A, the overall removal % of Ra-226, Ra-228 and Ra-228 was increased to ∼91 ± 3.5, 87 ± 4.1 and 90 ± 6.2%, respectively

  13. Chemical Diversity and Biological Activity of the Volatiles of Five Artemisia Species from Far East Russia

    Directory of Open Access Journals (Sweden)

    Gulmira Özek

    2014-05-01

    Full Text Available Artemisia argyi , A. feddei, A. gmelinii, A. manshurica, and A. olgensis (Asteraceae were collected in Far East Russia. Oils were hydrodistilled and simultaneously analyzed by GC-FID and GC/MS. Main constituents were found as follows in Artemisia oils: selin-11-en-4 a -ol (18.0%, 1,8-cineole (14.2.0%, artemisia alcohol (12.9%, borneol (9.7% in A. argyi; camphor (31.2%, 1,8-cineole (17.6%, a -thujone (5.7% in A. feddei; longiverbenone (12.0%, isopinocamphone (8.9%, 1,8-cineole (6.7%, camphor (5.8%, trans-p-menth-2-en-1-ol (5.3% in A. gmelinii; germacrene D (11.2%, rosifoliol (10.1%, caryophyllene oxide (6.8%, eudesma-4(15,7-dien-1 b -ol (5.6% in A. manshurica; eudesma-4(15,7-dien-1 b -ol (6.9%, caryophyllene oxide (5.6%, guaia-6,10(14-dien-4 b -ol (5.1% and hexadecanoic acid (5.0% in A. olgensis. Oils were subsequently submitted for antifungal and antimosquito evaluations. Artemisia species oils showed biting deterrent effects in Aedes aegypti and Artemisia gmelinii oil with the most active biting deterrence index values of 0.82 ± 0.1 at 10 m g/mL. Larval bioassay of A. gmelinii and A. olgensis oils showed higher larvicidal activity against Ae. aegypti larvae with LD50 values of 83.8 (72.6 – 95.7 ppm and 91.0 (73.8 – 114.5 ppm, respectively. Antifungal activity was evaluated against the strawberry anthracnose-causing fungal plant pathogens Colletotrichum acutatum, C. fragariae and C. gloeosporioides using direct overlay bioautography assay and all showed non-selective weak antifungal activity. Antioxidant evaluations of the oils were performed by using b -carotene bleaching, Trolox equivalent and DPPH tests. The tested Artemisia oils demonstrated moderate antioxidant activity.

  14. Reduced cost mission design using surrogate models

    Science.gov (United States)

    Feldhacker, Juliana D.; Jones, Brandon A.; Doostan, Alireza; Hampton, Jerrad

    2016-01-01

    This paper uses surrogate models to reduce the computational cost associated with spacecraft mission design in three-body dynamical systems. Sampling-based least squares regression is used to project the system response onto a set of orthogonal bases, providing a representation of the ΔV required for rendezvous as a reduced-order surrogate model. Models are presented for mid-field rendezvous of spacecraft in orbits in the Earth-Moon circular restricted three-body problem, including a halo orbit about the Earth-Moon L2 libration point (EML-2) and a distant retrograde orbit (DRO) about the Moon. In each case, the initial position of the spacecraft, the time of flight, and the separation between the chaser and the target vehicles are all considered as design inputs. The results show that sample sizes on the order of 102 are sufficient to produce accurate surrogates, with RMS errors reaching 0.2 m/s for the halo orbit and falling below 0.01 m/s for the DRO. A single function call to the resulting surrogate is up to two orders of magnitude faster than computing the same solution using full fidelity propagators. The expansion coefficients solved for in the surrogates are then used to conduct a global sensitivity analysis of the ΔV on each of the input parameters, which identifies the separation between the spacecraft as the primary contributor to the ΔV cost. Finally, the models are demonstrated to be useful for cheap evaluation of the cost function in constrained optimization problems seeking to minimize the ΔV required for rendezvous. These surrogate models show significant advantages for mission design in three-body systems, in terms of both computational cost and capabilities, over traditional Monte Carlo methods.

  15. Essential Oils from Leaves of Medicinal Plants of Brazilian Flora: Chemical Composition and Activity against Candida Species

    Directory of Open Access Journals (Sweden)

    Maria da Conceição Mendes Ferreira da Costa

    2017-05-01

    Full Text Available Background: The biotechnological potential of medicinal plants from Brazilian Caatinga and the Atlantic Forest has not been extensively studied. Thus, screening programs are important in prospecting for compounds for developing new drugs. The purpose of this study was to determine the chemical composition and to evaluate the anti-Candida activity of essential oils from leaves of Hymenaea courbaril var. courbaril, Myroxylon peruiferum, and Vismia guianensis. Methods: The oils were extracted through hydrodistillation and their chemical compositions were analyzed by gas chromatography coupled with mass spectrometry. Antifungal activity against C. albicans, C. tropicalis, C. parapsilosis, C. glabrata, and C. krusei was evaluated by determining the minimal inhibitory (MIC and fungicidal (MFC concentrations. Results: The major compounds of the oils were caryophyllene oxide and trans-caryophyllene for H. courbaril; spathulenol, α-pinene, and caryophyllene oxide for M. peruiferum; and caryophyllene oxide and humulene epoxide II for V. guianensis oil. The oils showed antifungal activity against all the strains tested, and the MIC values ranged between 0.625 and 1.25 μL/mL and MFC from 0.625 to 2.5 μL/mL. Conclusion: The essential oils from the species studied have the potential to be evaluated as clinical applications in the treatment of candidiasis.

  16. Characterization of n-heptane as a single component Diesel surrogate fuel. EHPC test set-up implementation

    Energy Technology Data Exchange (ETDEWEB)

    Meijer, M.

    2010-06-15

    The availability of accurately measured fuel properties, during an injection event under engine relevant conditions is critical within the surrogate fuel approach. There is a need to perform in-house measurements in order to validate developed and new models. A well defined and accurately measured data-set will facilitate on-going work for sophisticated engine related in-cylinder combustion modeling. In this work pure n-heptane fuel is used as a single component surrogate fuel and is studied in a high-pressure constant volume optical test set-up. N-heptane is often used as a single component surrogate diesel fuel since it has a comparable Cetane number as European diesel. Detailed chemical-kinetic mechanisms for low-, intermediate-, and high-temperature n-heptane oxidation are available and several models exist that have sufficiently reduced dimensionality (number of species and reactions) to enable their use in CFD (Computational Fluid Mechanics) simulations. This report discusses the route and implementation to perform such an accurate and relevant n-heptane measurement series. The aim is to combine the efforts of earlier presented EHPC (Eindhoven High Pressure Cell) related work and new approaches, into the proposed surrogate fuel measurement series. The following aspects, related to the applied constant volume combustion chamber set-up, are studied and implemented: Extending the operating ranges towards relevant engine conditions; Study the accuracy and sensitivities of the different measurement steps; Implementing different optical diagnostic principles; and Implement a standardized and robust post processing routine. The different optical diagnostic principles used in this work are: high-speed Schlieren, Mie scattering and beginnings are made to implement a simultaneous LII LIF (Laser Induced Incandescence - Laser Induced Fluorescence) set-up using a new ICCD (Intensified Charge Coupled Device) camera with dual imaging feature. Combining the different

  17. Influence of the mineralogical composition of cement in the diffusion of chemical species

    International Nuclear Information System (INIS)

    Galicia A, E.

    2015-01-01

    , color and others. Portland cements commonly used in the construction industry, they are based primarily on the mineral phases of limestone and silica. In conventional cement admixtures the chemical reactivity depends on the ratio of tricalcium and dicalcium silicate (C 3 S/C 2 S), the tricalcium aluminate (C 3 A) influences in the setting time and tetra calcium ferro aluminate (C 4 AF) gives a different color to the cement. In this research the mineralogical composition of two commercial cements is studied and its influence on the phenomenon of radionuclides retention. For this particular concrete discs were manufactured with water, sand and two commercial cements: Tolteca Extra CPC 30-RRS and Cruz Azul CPC Type II 30-R. The solid observation techniques used for analysis of the cement paste and concrete they are: X-ray Diffraction and Scanning Electron Microscopy, as well as the nuclear analytic techniques of Moessbauer and X-ray Fluorescence. (Author)

  18. Determination of thephysico-chemical 131I species in the exhausts and stack effluent of a PWR power plant

    International Nuclear Information System (INIS)

    Deuber, H.; Wilhelm, J.G.

    1979-01-01

    To quantify the credit that can be granted in the assessment of the 131 I ingestion doses and the improvement that can be achieved in the ventilation systems if differences of the physico-chemical 131 I species with respect to the environmental impact are taken into account, the fractions of the 131 I species were determined in the stack effluent and in various exhausts of a 1300 MW/sub e/ PWR power plant during a period of 3 months. Based on these measurements, calculations for different cases of filtration of the main exhausts for iodine were carried out. The average fractions of elemental and organic 131 I were about 70 and 30% respectively in the stack effluent during the time indicated. Elem. 131 I orginated mainly from the hoods in which samples of the primary coolant are taken and processed. Org. 131 I was mainly contributed by the equipment compartments. If the hood exhaust had been filtered, as was the case with the equipment compartment exhaust, the fractions of elem. and org. 131 I would have been on the order of 50% each and the calculated 131 I ingestion doses would have been a factor of 3 lower

  19. Auto-digital gain balancing: a new detection scheme for high-speed chemical species tomography of minor constituents

    International Nuclear Information System (INIS)

    Pal, Sandip; McCann, Hugh

    2011-01-01

    In many dynamic gas-phase reaction processes, there is great interest to measure the distribution of minor constituents, i.e. −3 by volume (1000 ppm). One such case is the after-treatment of automotive gasoline engine exhaust by catalytic conversion, where a characteristic challenge is to image the distribution of 10 ppm (average) of carbon monoxide (CO) at 1000 frames per second across a 50 mm diameter exhaust pipe; this particular problem has been pursued as a case study. In this paper, we present a novel electronic scheme that achieves the required measurement of around 10 −3 absorption with 10 −4 precision at kHz bandwidth. This was not previously achievable with any known technology. We call the new scheme Auto-Digital Gain Balancing. It is amenable to replication for many simultaneous measurement channels, and it permits simultaneous measurement of multiple species, in some circumstances. Experimental demonstrations are presented in the near-infrared. In single scans of a tunable diode laser, measurements of both CO and CO 2 have been made with 20 dB signal-to-noise ratio at peak absorption. This work paves the way for chemical species tomography of minor constituents in many dynamic gas-phase systems

  20. Mercury from combustion sources: a review of the chemical species emitted and their transport in the atmosphere

    International Nuclear Information System (INIS)

    Carpi, A.

    1997-01-01

    Different species of mercury have different physical/chemical properties and thus behave quite differentially in air pollution control equipment and in the atmosphere. In general, emission of mercury from coal combustion sources are approximately 20-50% elemental mercury (Hg 0 ) and 50-80% divalent mercury (Hg(II)), which may be predominantly HgCl 2 . Emissions of mercury from waste incinerators are approximately 10-20% Hg 0 and 75-85% Hg(II). The partitioning of mercury in flue gas between the elemental and divalent forms may be dependent on the concentration of particulate carbon, HCl and other pollutants in the stack emissions. The emission of mercury from combustion facilities depends on the species in the exhaust stream and the type of air pollution control equipment used at the source. Air pollution control equipment for mercury removal at combustion facilities includes activated carbon injection, sodium sulfide injection and wet lime/limestone flue gas desulfurization. White Hg(II) is water-soluble and may be removed form the atmosphere by wet and dry deposition close to the combustion sources, the combination of a high vapor pressure and low water-solubility facilitate the long-range transport of Hg 0 in the atmosphere. Background mercury in the atmosphere is predominantly Hg 0 . Elemental mercury is eventually removed from the atmosphere by dry deposition onto surfaces and by wet deposition after oxidation to water-soluble, divalent mercury. 62 refs., 2 figs., 1 tab

  1. Gene expression responses of HeLa cells to chemical species generated by an atmospheric plasma flow

    International Nuclear Information System (INIS)

    Yokoyama, Mayo; Johkura, Kohei; Sato, Takehiko

    2014-01-01

    Highlights: • Response of HeLa cells to a plasma-irradiated medium was revealed by DNA microarray. • Gene expression pattern was basically different from that in a H 2 O 2 -added medium. • Prominently up-/down-regulated genes were partly shared by the two media. • Gene ontology analysis showed both similar and different responses in the two media. • Candidate genes involved in response to ROS were detected in each medium. - Abstract: Plasma irradiation generates many factors able to affect the cellular condition, and this feature has been studied for its application in the field of medicine. We previously reported that hydrogen peroxide (H 2 O 2 ) was the major cause of HeLa cell death among the chemical species generated by high level irradiation of a culture medium by atmospheric plasma. To assess the effect of plasma-induced factors on the response of live cells, HeLa cells were exposed to a medium irradiated by a non-lethal plasma flow level, and their gene expression was broadly analyzed by DNA microarray in comparison with that in a corresponding concentration of 51 μM H 2 O 2 . As a result, though the cell viability was sufficiently maintained at more than 90% in both cases, the plasma-medium had a greater impact on it than the H 2 O 2 -medium. Hierarchical clustering analysis revealed fundamentally different cellular responses between these two media. A larger population of genes was upregulated in the plasma-medium, whereas genes were downregulated in the H 2 O 2 -medium. However, a part of the genes that showed prominent differential expression was shared by them, including an immediate early gene ID2. In gene ontology analysis of upregulated genes, the plasma-medium showed more diverse ontologies than the H 2 O 2 -medium, whereas ontologies such as “response to stimulus” were common, and several genes corresponded to “response to reactive oxygen species.” Genes of AP-1 proteins, e.g., JUN and FOS, were detected and notably elevated in

  2. Surrogate formulations for thermal treatment of low-level mixed waste

    International Nuclear Information System (INIS)

    Stockdale, J.A.D.; Bostick, W.D.; Hoffmann, D.P.; Lee, H.T.

    1994-01-01

    The evaluation and comparison of proposed thermal treatment systems for mixed wastes can be expedited by tests in which the radioactive components of the wastes are replaced by surrogate materials chosen to mimic, as far as is possible, the chemical and physical properties of the radioactive materials of concern. In this work, sponsored by the Mixed Waste Integrated Project of the US Department of Energy, the authors have examined reported experience with such surrogates and suggest a simplified standard list of materials for use in tests of thermal treatment systems. The chief radioactive nuclides of concern in the treatment of mixed wastes are 239 Pu, 238 U, 235 U, 137 Cs, 103 Ru, 99 Tc, and 90 Sr. These nuclides are largely by-products of uranium enrichment, reactor fuel reprocessing, and weapons program activities. Cs, Ru, and Sr all have stable isotopes that can be used as perfect surrogates for the radioactive forms. Technetium exists only in radioactive form, as do plutonium and uranium. If one wishes to preclude radioactive contamination of the thermal treatment system under trial burn, surrogate elements must be chosen for these three. For technetium, the authors suggest the use of natural ruthenium, and for both plutonium and uranium, they recommend cerium. The seven radionuclides listed can therefore be simulated by a surrogate package containing stable isotopes of ruthenium, strontium, cesium, and cerium

  3. Environmental and geographic variables are effective surrogates for genetic variation in conservation planning.

    Science.gov (United States)

    Hanson, Jeffrey O; Rhodes, Jonathan R; Riginos, Cynthia; Fuller, Richard A

    2017-11-28

    Protected areas buffer species from anthropogenic threats and provide places for the processes that generate and maintain biodiversity to continue. However, genetic variation, the raw material for evolution, is difficult to capture in conservation planning, not least because genetic data require considerable resources to obtain and analyze. Here we show that freely available environmental and geographic distance variables can be highly effective surrogates in conservation planning for representing adaptive and neutral intraspecific genetic variation. We obtained occurrence and genetic data from the IntraBioDiv project for 27 plant species collected over the European Alps using a gridded sampling scheme. For each species, we identified loci that were potentially under selection using outlier loci methods, and mapped their main gradients of adaptive and neutral genetic variation across the grid cells. We then used the cells as planning units to prioritize protected area acquisitions. First, we verified that the spatial patterns of environmental and geographic variation were correlated, respectively, with adaptive and neutral genetic variation. Second, we showed that these surrogates can predict the proportion of genetic variation secured in randomly generated solutions. Finally, we discovered that solutions based only on surrogate information secured substantial amounts of adaptive and neutral genetic variation. Our work paves the way for widespread integration of surrogates for genetic variation into conservation planning.

  4. Combining endangered plants and animals as surrogates to identify priority conservation areas in Yunnan, China

    Science.gov (United States)

    Yang, Feiling; Hu, Jinming; Wu, Ruidong

    2016-08-01

    Suitable surrogates are critical for identifying optimal priority conservation areas (PCAs) to protect regional biodiversity. This study explored the efficiency of using endangered plants and animals as surrogates for identifying PCAs at the county level in Yunnan, southwest China. We ran the Dobson algorithm under three surrogate scenarios at 75% and 100% conservation levels and identified four types of PCAs. Assessment of the protection efficiencies of the four types of PCAs showed that endangered plants had higher surrogacy values than endangered animals but that the two were not substitutable; coupled endangered plants and animals as surrogates yielded a higher surrogacy value than endangered plants or animals as surrogates; the plant-animal priority areas (PAPAs) was the optimal among the four types of PCAs for conserving both endangered plants and animals in Yunnan. PAPAs could well represent overall species diversity distribution patterns and overlap with critical biogeographical regions in Yunnan. Fourteen priority units in PAPAs should be urgently considered as optimizing Yunnan’s protected area system. The spatial pattern of PAPAs at the 100% conservation level could be conceptualized into three connected conservation belts, providing a valuable reference for optimizing the layout of the in situ protected area system in Yunnan.

  5. Videotrees: Improving video surrogate presentation using hierarchy

    NARCIS (Netherlands)

    Jansen, Michel; Heeren, W.F.L.; van Dijk, Elisabeth M.A.G.

    As the amount of available video content increases, so does the need for better ways of browsing all this material. Because the nature of video makes it hard to process, the need arises for adequate surrogates for video that can readily be skimmed and browsed. In this paper, the effects of the use

  6. Ethical Problems Related to Surrogate Motherhood

    Directory of Open Access Journals (Sweden)

    Erdem Aydin

    2006-03-01

    Full Text Available Being unable to have children is an important problem for married couples. At present, new reproduction techniques help these couples while those who can not find any solution try new approaches. One of these is the phenomenon of surrogate motherhood, which is based upon an agreement between the infertile couple and surrogate mother. Surrogate mother may conceive with the sperm of the male of the involved couple as well as by the transfer of the embryo formed by invitro fertilization. Couples who choose to have a child born from a pregnancy or to whom they are genetically partially connected rather than adopting a child give rise to the emergence of some ethical problems. Traditional family notion based upon having children after the union of the reproductive cells of the mother and father do not receive the pheneomenon of surrogate mother favourably. Such practices are criticised as they are far from being natural and other ethical problems are faced in the implementation.

  7. Active Subspaces for Wind Plant Surrogate Modeling

    Energy Technology Data Exchange (ETDEWEB)

    King, Ryan N [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Quick, Julian [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dykes, Katherine L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Adcock, Christiane [Massachusetts Institute of Technology

    2018-01-12

    Understanding the uncertainty in wind plant performance is crucial to their cost-effective design and operation. However, conventional approaches to uncertainty quantification (UQ), such as Monte Carlo techniques or surrogate modeling, are often computationally intractable for utility-scale wind plants because of poor congergence rates or the curse of dimensionality. In this paper we demonstrate that wind plant power uncertainty can be well represented with a low-dimensional active subspace, thereby achieving a significant reduction in the dimension of the surrogate modeling problem. We apply the active sub-spaces technique to UQ of plant power output with respect to uncertainty in turbine axial induction factors, and find a single active subspace direction dominates the sensitivity in power output. When this single active subspace direction is used to construct a quadratic surrogate model, the number of model unknowns can be reduced by up to 3 orders of magnitude without compromising performance on unseen test data. We conclude that the dimension reduction achieved with active subspaces makes surrogate-based UQ approaches tractable for utility-scale wind plants.

  8. A novel surrogate index for hepatic insulin resistance.

    LENUS (Irish Health Repository)

    Vangipurapu, J

    2011-03-01

    In epidemiological and genetic studies surrogate indices are needed to investigate insulin resistance in different insulin-sensitive tissues. Our objective was to develop a surrogate index for hepatic insulin resistance.

  9. Surrogate losses: Understandings of pregnancy loss and assisted reproduction among surrogate mothers.

    Science.gov (United States)

    Berend, Zsuzsa

    2010-06-01

    I explore surrogate mothers' narrative construction of pregnancy loss on surrogacy support websites. Communicating via the Internet, women construct the public online world of surrogacy. Drawing on anthropological and sociological literature I investigate the connections between conceptualizations of loss and understandings of technological practices and the consequences of these understandings for assisted reproduction. Surrogate mothers define loss broadly, ranging from failure to conceive to miscarriage and stillbirth; loss means the failure to give a baby to the intended parents. Assisted reproductive technologies contribute to loss by raising expectations of success, by attempting to maximize results through the transfer of multiple fertilized ova, and by early monitoring and testing. However, surrogates collectively understand technology as a positive force and advocate for reproductive technology. Surrogates' resolve to "give the gift of life" makes them vulnerable to failure and loss, yet also informs repeated efforts to bear children for others with technological assistance.

  10. Characterization of surrogate radioactive cemented waste: a laboratory study

    International Nuclear Information System (INIS)

    Fiset, J.F.; Lastra, R.; Bilodeau, A.; Bouzoubaa

    2011-01-01

    Portland cement is commonly used to stabilize intermediate and low level of radioactive wastes. The stabilization/solidification process needs to be well understood as waste constituents can retard or activate cement hydration. The objectives of this project were to prepare surrogate radioactive cemented waste (SRCW), develop a comminution strategy for SRCW, determine its chemical characteristics, and develop processes for long term storage. This paper emphasizes on the characterization of surrogate radioactive cemented waste. The SRCW produced showed a high degree of heterogeneity mainly due to the method used to add the solution to the host cement. Heavy metals such as uranium and mercury were not distributed uniformly in the pail. Mineralogical characterization (SEM, EDS) showed that uranium is located around the rims of hydrated cement particles. In the SRCW, uranium occurs possibly in the form of a hydrated calcium uranate.The SEM-EDS results also suggest that mercury occurs mainly in the form of HgO although some metallic mercury may be also present as a result of partial decomposition of the HgO. (author)

  11. Chemical contamination assessment in mangrove-lined Caribbean coastal systems using the oyster Crassostrea rhizophorae as biomonitor species.

    Science.gov (United States)

    Aguirre-Rubí, Javier R; Luna-Acosta, Andrea; Etxebarría, Nestor; Soto, Manu; Espinoza, Félix; Ahrens, Michael J; Marigómez, Ionan

    2018-05-01

    This paper aims to contribute to the use of mangrove cupped oyster, Crassostrea rhizophorae, as a biomonitor species for chemical contamination assessment in mangrove-lined Caribbean coastal systems. Sampling was carried out in eight localities (three in Nicaragua and five in Colombia) with different types and levels of contamination. Oysters were collected during the rainy and dry seasons of 2012-2013 and the tissue concentrations of metals, polycyclic aromatic hydrocarbons (PAHs), and persistent organic pollutants (POPs) were determined. Low tissue concentrations of metals (except Hg) and PAHs; moderate-to-high tissue concentrations of Hg, hexachlorocyclohexanes (HCHs), and dichlorodiphenyl-trichloroethanes (DDTs); detectable levels of chlorpyrifos, polychlorinated biphenyls (PCBs) (mainly CB28, CB118, CB138 and CB 153) and brominated diphenyl ethers 85 (BDE85); and negligible levels of musks were recorded in Nicaraguan oysters. A distinct profile of POPs was identified in Colombia, where the tissue concentrations of PCBs and synthetic musk fragrances were low to moderate, and Ag, As, Cd, Pb, and PAHs ranged from moderate to extremely high. Overall, the values recorded for HCHs, DDTs and PCBs in Nicaraguan mangrove cupped oysters greatly exceeded the reference values in tissues of C. rhizophorae from the Wider Caribbean Region, whereas only the levels of PCBs were occasionally surpassed in Colombia. Different contaminant profiles were distinguished between oysters from Nicaragua and Colombia in radar plots constructed using the main groups of contaminants (metals, PAHs, musks, PCBs, and organochlorine pesticides (OCPs)). Likewise, integrated pollution indices revealed differences in the levels of contaminants. Moreover, the profiles and levels in oyster tissues also varied with season. Thus, principal component analysis clearly discriminated Nicaraguan and Colombian localities and, especially in Colombia, seasonal trends in chemical contamination and differences

  12. Chemical vapor generation of silver for atomic absorption spectrometry with the multiatomizer: Radiotracer efficiency study and characterization of silver species

    Energy Technology Data Exchange (ETDEWEB)

    Musil, Stanislav [Institute of Analytical Chemistry of the ASCR, v.v.i., Videnska 1083, 142 20 Prague 4 (Czech Republic); Charles University in Prague, Faculty of Science, Dept. of Analytical Chemistry, Albertov 8, 128 43 Prague 2 (Czech Republic); Kratzer, Jan; Vobecky, Miloslav [Institute of Analytical Chemistry of the ASCR, v.v.i., Videnska 1083, 142 20 Prague 4 (Czech Republic); Hovorka, Jan [Charles University in Prague, Faculty of Science, Institute for Environmental Studies, Benatska 2, 128 01 Prague 2 (Czech Republic); Benada, Oldrich [Institute of Microbiology of the ASCR, v.v.i., Videnska 1083, 142 20 Prague 4 (Czech Republic); Matousek, Tomas, E-mail: matousek@biomed.cas.c [Institute of Analytical Chemistry of the ASCR, v.v.i., Videnska 1083, 142 20 Prague 4 (Czech Republic)

    2009-11-15

    Volatile Ag species were generated in flow injection arrangement from nitric acid environment in the presence of surfactants (Triton X-100 and Antifoam B) and permanent Pd deposits as the reaction modifiers. Atomic absorption spectrometry (AAS) with multiple microflame quartz tube atomizer heated to 900 deg. C was used for atomization; evidence was found for thermal mechanism of atomization. Relative and absolute limits of detection (3sigma, 250 mul sample loop) measured under optimized conditions were: 1.4 mug l{sup -1} and 0.35 ng, respectively. The efficiency of chemical vapor generation (CVG) as well as spatial distribution of residual analyte in the apparatus was studied by {sup 111}Ag radioactive indicator (half-life 7.45 days) of high specific activity. It was found out that 23% of analyte was released into the gaseous phase. However, only 8% was found on filters placed at the entrance to the atomizer due to transport losses. About 40% of analyte remained in waste liquid, whereas the rest was found deposited over the CVG system. Presented study follows the hypothesis that the 'volatile' Ag species are actually metallic nanoparticles formed upon reduction in liquid phase and then released with good efficiency to the gaseous phase. Number/charge size distributions of dry aerosol were determined by Scanning Mobility Particle Sizer. Ag was detected in 40-45 nm particles holding 10 times more charge if compared to Boltzmann equilibrium. At the same time, Ag was also present on 150 nm particles, the main size mode of the CVG generator. The increase of Ag in standards was reflected by proportional increase in particle number/charge for 40-45 nm size particles only. Transmission electron microscopy revealed particles of 8 +- 2 nm sampled from the gaseous phase, which were associated in isolated clusters of few to few tens of nanometres. Ag presence in those particles was confirmed by Energy Dispersive X-ray Spectroscopy (EDS) analysis.

  13. Pig and guinea pig skin as surrogates for human in vitro penetration studies: a quantitative review.

    Science.gov (United States)

    Barbero, Ana M; Frasch, H Frederick

    2009-02-01

    Both human and animal skin in vitro models are used to predict percutaneous penetration in humans. The objective of this review is a quantitative comparison of permeability and lag time measurements between human and animal skin, including an evaluation of the intra and inter species variability. We limit our focus to domestic pig and rodent guinea pig skin as surrogates for human skin, and consider only studies in which both animal and human penetration of a given chemical were measured jointly in the same lab. When the in vitro permeability of pig and human skin were compared, the Pearson product moment correlation coefficient (r) was 0.88 (Ppig and 35% for human, and an inter species average coefficient of variation of 37% for the set of studied compounds (n=41). The lag times of pig skin and human skin did not correlate (r=0.35, P=0.26). When the in vitro permeability of guinea pig and human skin were compared, r=0.96 (Pguinea pig and 24% for human, and an inter species coefficient of variation of permeability of 41% for the set of studied compounds (n=15). Lag times of guinea pig and human skin correlated (r=0.90, Ppig skin (n=50) and guinea pig skin (n=25). For pig skin, 80% of measurements fell within the range 0.3guinea pig skin, 65% fell within that range. Both pig and guinea pig are good models for human skin permeability and have less variability than the human skin model. The skin model of choice will depend on the final purpose of the study and the compound under investigation.

  14. System Reliability Analysis Capability and Surrogate Model Application in RAVEN

    Energy Technology Data Exchange (ETDEWEB)

    Rabiti, Cristian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Alfonsi, Andrea [Idaho National Lab. (INL), Idaho Falls, ID (United States); Huang, Dongli [Idaho National Lab. (INL), Idaho Falls, ID (United States); Gleicher, Frederick [Idaho National Lab. (INL), Idaho Falls, ID (United States); Wang, Bei [Idaho National Lab. (INL), Idaho Falls, ID (United States); Adbel-Khalik, Hany S. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Pascucci, Valerio [Idaho National Lab. (INL), Idaho Falls, ID (United States); Smith, Curtis L. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-11-01

    This report collect the effort performed to improve the reliability analysis capabilities of the RAVEN code and explore new opportunity in the usage of surrogate model by extending the current RAVEN capabilities to multi physics surrogate models and construction of surrogate models for high dimensionality fields.

  15. Natural background levels and threshold values of chemical species in three large-scale groundwater bodies in Northern Italy

    International Nuclear Information System (INIS)

    Molinari, Antonio; Guadagnini, Laura; Marcaccio, Marco; Guadagnini, Alberto

    2012-01-01

    We analyze natural background levels (NBLs) and threshold values (TVs) of spatially distributed chemical species (NH 4 , B and As) which may be a potential pressure and concern in three large scale alluvial and fluvio-deltaic aquifers at different depths of the Apennines and Po river plains in Emilia–Romagna, Northern Italy. Our results are based on statistical methodologies designed to separate the natural and anthropogenic contributions in monitored concentrations by modeling the empirical distribution of the detected concentration with a mixture of probability density functions. Available chemical observations are taken over a 20 years period and are associated with different depths and cover planar investigation scales of the order of hundreds of kilometers. High concentration values detected for NH 4 and B appear to be related to high natural background levels. Due to interaction with the host rock in different geochemical environments we observed that concentration vary in time and space (including in depth) consistently with the hydrogeochemical features and the occurrence of natural attenuation mechanisms in the analyzed reservoirs. Conversely, estimated As NBLs are not consistent with the conceptual model of the hydrogeochemical behavior of the systems analyzed and experimental evidences of As content in aquifer cores. This is due to the inability of these techniques to incorporate the complex dynamics of the processes associated with the specific hydrogeochemical setting. Statistical analyses performed upon aggregating the concentration data according to different time observation windows allow identifying temporal dynamics of NBLs and TVs of target compounds within the observation time frame. Our results highlight the benefit of a dynamic monitoring process and analysis of well demarcated groundwater bodies to update the associated NBLs as a function of the temporal dependence of natural processes occurring in the subsurface. Monitoring protocols could

  16. Natural background levels and threshold values of chemical species in three large-scale groundwater bodies in Northern Italy

    Energy Technology Data Exchange (ETDEWEB)

    Molinari, Antonio, E-mail: ant.molinari2002@libero.it [Politecnico di Milano, Dipartimento di Ingegneria Idraulica, Ambientale, Infrastrutture Viarie e Rilevamento, Piazza L. Da Vinci, 32-20133 Milano (Italy); Guadagnini, Laura [Politecnico di Milano, Dipartimento di Ingegneria Idraulica, Ambientale, Infrastrutture Viarie e Rilevamento, Piazza L. Da Vinci, 32-20133 Milano (Italy); Marcaccio, Marco [ARPA Emilia-Romagna, Direzione Tecnica, Largo Caduti del Lavoro, 6-40122 Bologna (Italy); Guadagnini, Alberto [Politecnico di Milano, Dipartimento di Ingegneria Idraulica, Ambientale, Infrastrutture Viarie e Rilevamento, Piazza L. Da Vinci, 32-20133 Milano (Italy)

    2012-05-15

    We analyze natural background levels (NBLs) and threshold values (TVs) of spatially distributed chemical species (NH{sub 4}, B and As) which may be a potential pressure and concern in three large scale alluvial and fluvio-deltaic aquifers at different depths of the Apennines and Po river plains in Emilia-Romagna, Northern Italy. Our results are based on statistical methodologies designed to separate the natural and anthropogenic contributions in monitored concentrations by modeling the empirical distribution of the detected concentration with a mixture of probability density functions. Available chemical observations are taken over a 20 years period and are associated with different depths and cover planar investigation scales of the order of hundreds of kilometers. High concentration values detected for NH{sub 4} and B appear to be related to high natural background levels. Due to interaction with the host rock in different geochemical environments we observed that concentration vary in time and space (including in depth) consistently with the hydrogeochemical features and the occurrence of natural attenuation mechanisms in the analyzed reservoirs. Conversely, estimated As NBLs are not consistent with the conceptual model of the hydrogeochemical behavior of the systems analyzed and experimental evidences of As content in aquifer cores. This is due to the inability of these techniques to incorporate the complex dynamics of the processes associated with the specific hydrogeochemical setting. Statistical analyses performed upon aggregating the concentration data according to different time observation windows allow identifying temporal dynamics of NBLs and TVs of target compounds within the observation time frame. Our results highlight the benefit of a dynamic monitoring process and analysis of well demarcated groundwater bodies to update the associated NBLs as a function of the temporal dependence of natural processes occurring in the subsurface. Monitoring

  17. Determining High-Quality Critical Body Residues for Multiple Species and Chemicals by Applying Improved Experimental Design and Data Interpretation Concepts

    DEFF Research Database (Denmark)

    van der Heijden, Stephan A.; Hermens, Joop L. M.; Sinnige, Theo L.

    2015-01-01

    Ecotoxicological effect data are generally expressed as effective concentrations in the external exposure medium and do thus not account for differences in chemical uptake, bioavailability, and metabolism, which can introduce substantial data variation. The Critical Body Residue (CBR) concept......, and by a factor of 2.6 between the three species but for individual chemicals. Accounting for the chemicals internal distribution to different partitioning domains and relating effects to estimated concentrations in the target compartment (i.e., membrane lipids) was expected to but did not decrease the overall...

  18. Chemical composition of 8 eucalyptus species' essential oils and the evaluation of their antibacterial, antifungal and antiviral activities

    Directory of Open Access Journals (Sweden)

    Elaissi Ameur

    2012-06-01

    Full Text Available Abstract Background In 1957, Tunisia introduced 117 species of Eucalyptus; they have been used as fire wood, for the production of mine wood and to fight erosion. Actually, Eucalyptus essential oil is traditionally used to treat respiratory tract disorders such as pharyngitis, bronchitis, and sinusitis. A few investigations were reported on the biological activities of Eucalyptus oils worldwide. In Tunisia, our previous works conducted in 2010 and 2011 had been the first reports to study the antibacterial activities against reference strains. At that time it was not possible to evaluate their antimicrobial activities against clinical bacterial strains and other pathogens such as virus and fungi. Methods The essential oils of eight Eucalyptus species harvested from the Jbel Abderrahman, Korbous (North East Tunisia and Souinet arboreta (North of Tunisia were evaluated for their antimicrobial activities by disc diffusion and microbroth dilution methods against seven bacterial isolates: Haemophilus influenzae, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus pneumoniae and Streptococcus pyogenes. In addition, the bactericidal, fungicidal and the antiviral activities of the tested oils were carried out. Results Twenty five components were identified by GC/FID and GC/MS. These components were used to correlate with the biological activities of the tested oils. The chemical principal component analysis identified three groups, each of them constituted a chemotype. According to the values of zone diameter and percentage of the inhibition (zdi, % I, respectively, four groups and subgroups of bacterial strains and three groups of fungal strains were characterized by their sensitivity levels to Eucalyptus oils. The cytotoxic effect and the antiviral activity varied significantly within Eucalyptus species oils. Conclusions E. odorata showed the strongest activity against S. aureus, H. influenzae

  19. Chemical composition of 8 eucalyptus species' essential oils and the evaluation of their antibacterial, antifungal and antiviral activities

    Science.gov (United States)

    2012-01-01

    Background In 1957, Tunisia introduced 117 species of Eucalyptus; they have been used as fire wood, for the production of mine wood and to fight erosion. Actually, Eucalyptus essential oil is traditionally used to treat respiratory tract disorders such as pharyngitis, bronchitis, and sinusitis. A few investigations were reported on the biological activities of Eucalyptus oils worldwide. In Tunisia, our previous works conducted in 2010 and 2011 had been the first reports to study the antibacterial activities against reference strains. At that time it was not possible to evaluate their antimicrobial activities against clinical bacterial strains and other pathogens such as virus and fungi. Methods The essential oils of eight Eucalyptus species harvested from the Jbel Abderrahman, Korbous (North East Tunisia) and Souinet arboreta (North of Tunisia) were evaluated for their antimicrobial activities by disc diffusion and microbroth dilution methods against seven bacterial isolates: Haemophilus influenzae, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus pneumoniae and Streptococcus pyogenes. In addition, the bactericidal, fungicidal and the antiviral activities of the tested oils were carried out. Results Twenty five components were identified by GC/FID and GC/MS. These components were used to correlate with the biological activities of the tested oils. The chemical principal component analysis identified three groups, each of them constituted a chemotype. According to the values of zone diameter and percentage of the inhibition (zdi, % I, respectively), four groups and subgroups of bacterial strains and three groups of fungal strains were characterized by their sensitivity levels to Eucalyptus oils. The cytotoxic effect and the antiviral activity varied significantly within Eucalyptus species oils. Conclusions E. odorata showed the strongest activity against S. aureus, H. influenzae, S. agalactiae, S. pyogenes

  20. Effect of salt species on electrochemical properties of gel-type polymer electrolyte based on chemically crosslinking rubber

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kab Youl; Jo, Nam Ju [Pusan National Univ., Busan (Korea). Dept. of Polymer Science and Engineering; Chung, Won Sub [Pusan National Univ., Busan (Korea). School of Materials Science and Engineering

    2004-11-30

    In our study, for ion-polymer interaction in gel-type polymer electrolyte (GPE), two kinds of ions were used. GPE systems were composed of Mg or Li salt, organic solvent ({gamma}-BL), and polymer matrix prepared by chemical crosslinking of NBR with poly(ethylene glycol) methylethermethacrylate (PEGMEM) having polar group (--CH{sub 2}--CH{sub 2}--O--) in the side chain of monomer. GPE consisting of Li{sup +} ion had higher ionic conductivity than that of Mg{sup 2+} ion at below 100 wt.% of electrolyte content (1 M salt/{gamma}-BL). On the other hand, GPE consisting of Mg{sup 2+} ion had higher ionic conductivity than that consisting of Li{sup +} ion at over 120 wt.% of electrolyte content (1 M salt/{gamma}-BL). The maximum liquid electrolyte content was 200 wt.% for all GPE systems. And the highest ionic conductivity of 3.3 x 10{sup -2} S cm{sup -1} was achieved for the case of Mg{sup 2+}-GPE with 200 wt.% of liquid electrolyte contents at 20 C. The interaction between ionic species and polymer matrix in GPE was investigated by using Fourier transform infrared spectroscopy (FT-IR). Also, cyclic voltammogram of Mg{sup 2+}-GPE confirmed the electrochemical property of divalent cation with two electron-transfer reactions.

  1. The role of the gas species on the formation of carbon nanotubes during thermal chemical vapour deposition

    International Nuclear Information System (INIS)

    Ohashi, Fumitaka; Chen, Guan Yow; Stolojan, Vlad; Silva, S Ravi P

    2008-01-01

    In this paper, we investigate the several roles that hydrogen plays in the catalytic growth of carbon nanotubes from the point of view of gas species, catalyst activation and subsequent interaction with the carbon nanotubes. Carbon nanotubes and nanofibres were grown by thermal chemical vapour deposition, using methane and a mixture of hydrogen and helium, for a range of growth temperatures and pre-treatment procedures. Long, straight carbon nanotubes were obtained at 900 deg. C, and although the growth yield increases with the growth temperature, the growth shifts from nanotubes to nanofibres. By introducing a helium purge as part of the pre-treatment procedure, we change the gas chemistry by altering the hydrogen concentration in the initial reaction stage. This simple change in the process resulted in a clear difference in the yield and the structure of the carbon nanofibres produced. We find that the hydrogen concentration in the initial reaction stage significantly affects the morphology of carbon fibres. Although hydrogen keeps the catalyst activated and increases the yield, it prevents the formation of graphitic nanotubes.

  2. Chemical Composition and Insecticidal Activity of Essential Oils from Zanthoxylum dissitum Leaves and Roots against Three Species of Storage Pests.

    Science.gov (United States)

    Wang, Cheng-Fang; Yang, Kai; You, Chun-Xue; Zhang, Wen-Juan; Guo, Shan-Shan; Geng, Zhu-Feng; Du, Shu-Shan; Wang, Yong-Yan

    2015-05-04

    This work aimed to investigate chemical composition of essential oils obtained from Zanthoxylum dissitum leaves and roots and their insecticidal activities against several stored product pests, namely the cigarette beetle (Lasioderma serricorne), red flour beetle (Tribolium castaneum) and black carpet beetle (Attagenus piceus). The analysis by GC-MS of the essential oils allowed the identification of 28 and 22 components, respectively. It was found that sesquiterpenoids comprised a fairly high portion of the two essential oils, with percentages of 74.0% and 80.9% in the leaves and roots, respectively. The main constituents identified in the essential oil of Z. dissitum leaves were δ-cadinol (12.8%), caryophyllene (12.7%), β-cubebene (7.9%), 4-terpineol (7.5%) and germacrene D-4-ol (5.7%), while humulene epoxide II (29.4%), caryophyllene oxide (24.0%), diepicedrene-1-oxide (10.7%) and Z,Z,Z-1,5,9,9-tetramethyl-1,4,7-cycloundecatriene (8.7%) were the major components in the essential oil of Z. dissitum roots. The insecticidal activity results indicated that the essential oil of Z. dissitum roots exhibited moderate contact toxicity against three species of storage pests, L. serricorne,T. castaneum and A. piceus, with LD50 values of 13.8, 43.7 and 96.8 µg/adult, respectively.

  3. Criteria on global boundedness versus finite time blow-up to a two-species chemotaxis system with two chemicals

    Science.gov (United States)

    Yu, Hao; Wang, Wei; Zheng, Sining

    2018-02-01

    This paper considers the two-species chemotaxis system with two chemicals in a smooth bounded domain Ω\\subset{R}2 , subject to the non-flux boundary condition, and χ, ξ, α, β, γ, δ>0 . We obtain a blow-up criterion that if m_1m_2-2π(\\frac{m_1}χβ+\\frac{m_2}ξδ)>0 , then there exist finite time blow-up solutions to the system with m_1:=\\int_Ω u_0(x)dx and m_2:=\\int_Ω w_0(x)dx . When χ=ξ= β=δ=1 , the blow-up criterion becomes m_1m_2-2π(m_1+m_2)>0 , and the global boundedness of solutions is furthermore established with α=γ=1 under the condition that \\max\\{m_1, m_2\\}4π and global boundedness with \\max\\{m_1, m_2\\}Funds for the Central Universities (DUT16LK24).

  4. The Effect of Chemical Treatments on Lampenflora and a Collembola Indicator Species at a Popular Tour Cave in California, USA

    Science.gov (United States)

    Meyer, Erik; Seale, L. Don; Permar, Brianne; McClary, Andrew

    2017-06-01

    Growth of invasive, opportunistic plants (i.e. lampenflora) in popular tour caves is a significant concern for land managers worldwide. Numerous chemicals at various concentrations have been utilized to remove phototrophic lampenflora colonizing artificially lit surfaces within these caves; however formulations, effectiveness, and impacts appear anecdotal and temporally limited. At Crystal Cave, Sequoia National Park, California, we study lampenflora and cave springtail ( Tomocerus celsus) response to a single 0.05 ml/cm2 dose of 1.0% sodium hypochlorite, 0.5% sodium hypochlorite, and 15.0% hydrogen peroxide compared to no treatment over the course of one year. Additionally, we explore potential food web impacts resulting from invasive lampenflora in naturally oligotrophic caves by utilizing stable isotope analysis of T. celsus found on and off lampenflora. Time-effect decay models indicate 1.0 and 0.5% sodium hypochlorite effectively eliminate lampenflora in 11 and 21 days, respectively, while lampenflora decay projections exceed 600 days with 15.0% hydrogen peroxide treatment. Repeat surveys of T. celsus indicate a negative response to 1.0% sodium hypochlorite ( P = 0.02), and the probability of observing T. celsus was inversely related to the effectiveness of each treatment. Further, T. celsus had similar diets regardless of their lampenflora association ( P = 0.92). We conclude that treatments of sodium hypochlorite at or below 0.5% achieve management goals with limited impacts to the presence or diet of a common cave-adapted indicator species.

  5. Analysis of Chemical Species Along the Process Stages of Demineralized Water Production at Reactor G.A. Siwabessy

    International Nuclear Information System (INIS)

    Nurul Huda; Setyono; Sumijanto; Diah E L; Ihsan, M.

    2003-01-01

    The tank water of multipurpose reactor G.A. Siwabessy is supplied from a water demineralization plant which works based on ion exchange processes. Controlling the quality of the water produced by this plant is one of many factor which effects the quality of the reactor tank water. This experiment resulted a characteristic pattern data of water and its chemical species content along process stages of demineralized water production at the reactor. The experiment results showed that the pH (degree of acidity), electric conductivity and dissolved cation (Ca 2+ , Mg 2+ ) lied at the permissible range. The value fluctuation of these variables showed a right pattern. It can be concluded that the water produced by this plant met the requirements to be used as primary cooling water of the reactor. However, the value of pH is still too low although it lied in the tolerance limit. Beside that, it isn't all of water impurities concentration can be predicted by the value of pH and conductivity. Therefore, the determination of water quality for the need of reactor tank water quiet to be done continually to keep the water condition in order to meet the quality required, and to evaluate and developed its production technology. (author)

  6. Gene expression responses of HeLa cells to chemical species generated by an atmospheric plasma flow

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Mayo, E-mail: yokoyama@plasma.ifs.tohoku.ac.jp [Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Johkura, Kohei, E-mail: kohei@shinshu-u.ac.jp [Department of Histology and Embryology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621 (Japan); Sato, Takehiko, E-mail: sato@ifs.tohoku.ac.jp [Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)

    2014-08-08

    Highlights: • Response of HeLa cells to a plasma-irradiated medium was revealed by DNA microarray. • Gene expression pattern was basically different from that in a H{sub 2}O{sub 2}-added medium. • Prominently up-/down-regulated genes were partly shared by the two media. • Gene ontology analysis showed both similar and different responses in the two media. • Candidate genes involved in response to ROS were detected in each medium. - Abstract: Plasma irradiation generates many factors able to affect the cellular condition, and this feature has been studied for its application in the field of medicine. We previously reported that hydrogen peroxide (H{sub 2}O{sub 2}) was the major cause of HeLa cell death among the chemical species generated by high level irradiation of a culture medium by atmospheric plasma. To assess the effect of plasma-induced factors on the response of live cells, HeLa cells were exposed to a medium irradiated by a non-lethal plasma flow level, and their gene expression was broadly analyzed by DNA microarray in comparison with that in a corresponding concentration of 51 μM H{sub 2}O{sub 2}. As a result, though the cell viability was sufficiently maintained at more than 90% in both cases, the plasma-medium had a greater impact on it than the H{sub 2}O{sub 2}-medium. Hierarchical clustering analysis revealed fundamentally different cellular responses between these two media. A larger population of genes was upregulated in the plasma-medium, whereas genes were downregulated in the H{sub 2}O{sub 2}-medium. However, a part of the genes that showed prominent differential expression was shared by them, including an immediate early gene ID2. In gene ontology analysis of upregulated genes, the plasma-medium showed more diverse ontologies than the H{sub 2}O{sub 2}-medium, whereas ontologies such as “response to stimulus” were common, and several genes corresponded to “response to reactive oxygen species.” Genes of AP-1 proteins, e.g., JUN

  7. Relationships between respiration, chemical and microbial properties of afforested mine soils with different soil texture and tree species: Does the time of incubation matter

    Czech Academy of Sciences Publication Activity Database

    Józefowska, A.; Pietrzykowski, M.; Woś, B.; Cajthaml, T.; Frouz, Jan

    2017-01-01

    Roč. 80, May (2017), s. 102-109 ISSN 1164-5563 Institutional support: RVO:60077344 Keywords : afforested mine soils * soil texture * tree species * chemical properties * microbial properties Subject RIV: DF - Soil Science OBOR OECD: Soil science Impact factor: 2.445, year: 2016

  8. Chemical characterization of 21 species of marine macroalgae common in Norwegian waters: benefits of and limitations to their potential use in food and feed.

    Science.gov (United States)

    Biancarosa, Irene; Belghit, Ikram; Bruckner, Christian G; Liland, Nina S; Waagbø, Rune; Amlund, Heidi; Heesch, Svenja; Lock, Erik-Jan

    2018-03-01

    In the past few years, much effort has been invested into developing a new blue economy based on harvesting, cultivating and processing marine macroalgae in Norway. Macroalgae have high potential for a wide range of applications, e.g. as source of pharmaceuticals, production of biofuels or as food and feed. However, data on the chemical composition of macroalgae from Norwegian waters are scant. This study was designed to characterize the chemical composition of 21 algal species. Both macro- and micronutrients were analysed. Concentrations of heavy metals and the metalloid arsenic in the algae were also quantified. The results confirm that marine macroalgae contain nutrients which are relevant for both human and animal nutrition, the concentrations whereof are highly dependent on species. Although heavy metals and arsenic were detected in the algae studied, concentrations were mostly below maximum allowed levels set by food and feed legislation in the EU. This study provides chemical data on a wide range of algal species covering the three taxonomic groups (brown, red and green algae) and discusses both benefits of and potential limitations to their use for food and feed purposes. © 2017 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2017 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

  9. Surrogate decision making and intellectual virtue.

    Science.gov (United States)

    Bock, Gregory L

    2014-01-01

    Patients can be harmed by a religiously motivated surrogate decision maker whose decisions are contrary to the standard of care; therefore, surrogate decision making should be held to a high standard. Stewart Eskew and Christopher Meyers proposed a two-part rule for deciding which religiously based decisions to honor: (1) a secular reason condition and (2) a rationality condition. The second condition is based on a coherence theory of rationality, which they claim is accessible, generous, and culturally sensitive. In this article, I will propose strengthening the rationality condition by grounding it in a theory of intellectual virtue, which is both rigorous and culturally sensitive. Copyright 2014 The Journal of Clinical Ethics. All rights reserved.

  10. Self- and surrogate-reported communication functioning in aphasia.

    Science.gov (United States)

    Doyle, Patrick J; Hula, William D; Austermann Hula, Shannon N; Stone, Clement A; Wambaugh, Julie L; Ross, Katherine B; Schumacher, James G

    2013-06-01

    To evaluate the dimensionality and measurement invariance of the aphasia communication outcome measure (ACOM), a self- and surrogate-reported measure of communicative functioning in aphasia. Responses to a large pool of items describing communication activities were collected from 133 community-dwelling persons with aphasia of ≥ 1 month post-onset and their associated surrogate respondents. These responses were evaluated using confirmatory and exploratory factor analysis. Chi-square difference tests of nested factor models were used to evaluate patient-surrogate measurement invariance and the equality of factor score means and variances. Association and agreement between self- and surrogate reports were examined using correlation and scatterplots of pairwise patient-surrogate differences. Three single-factor scales (Talking, Comprehension, and Writing) approximating patient-surrogate measurement invariance were identified. The variance of patient-reported scores on the Talking and Writing scales was higher than surrogate-reported variances on these scales. Correlations between self- and surrogate reports were moderate-to-strong, but there were significant disagreements in a substantial number of individual cases. Despite minimal bias and relatively strong association, surrogate reports of communicative functioning in aphasia are not reliable substitutes for self-reports by persons with aphasia. Furthermore, although measurement invariance is necessary for direct comparison of self- and surrogate reports, the costs of obtaining invariance in terms of scale reliability and content validity may be substantial. Development of non-invariant self- and surrogate report scales may be preferable for some applications.

  11. Surrogate end points in clinical research: hazardous to your health.

    Science.gov (United States)

    Grimes, David A; Schulz, Kenneth F

    2005-05-01

    Surrogate end points in clinical research pose real danger. A surrogate end point is an outcome measure, commonly a laboratory test, that substitutes for a clinical event of true importance. Resistance to activated protein C, for example, has been used as a surrogate for venous thrombosis in women using oral contraceptives. Other examples of inappropriate surrogate end points in contraception include the postcoital test instead of pregnancy to evaluate new spermicides, breakage and slippage instead of pregnancy to evaluate condoms, and bone mineral density instead of fracture to assess the safety of depo-medroxyprogesterone acetate. None of these markers captures the effect of the treatment on the true outcome. A valid surrogate end point must both correlate with and accurately predict the outcome of interest. Although many surrogate markers correlate with an outcome, few have been shown to capture the effect of a treatment (for example, oral contraceptives) on the outcome (venous thrombosis). As a result, thousands of useless and misleading reports on surrogate end points litter the medical literature. New drugs have been shown to benefit a surrogate marker, but, paradoxically, triple the risk of death. Thousands of patients have died needlessly because of reliance on invalid surrogate markers. Researchers should avoid surrogate end points unless they have been validated; that requires at least one well done trial using both the surrogate and true outcome. The clinical maxim that "a difference to be a difference must make a difference" applies to research as well. Clinical research should focus on outcomes that matter.

  12. [Biomedical Perspective of the Surrogate Motherhood].

    Science.gov (United States)

    Jouve de la Barreda, Nicolás

    2017-01-01

    The subrogated motherhood takes place when an embryo created by in vitro fertilization (IVF) technology is implanted in a surrogate, sometimes called a gestational mother, by means a contract with her. It can imply to natural families (woman and man) with or without infertility problems, or to monoparental or biparental families of the same sex. Concerning the origin of the gametes used in the IVF emerges different implications on the genetic relationship of the resulting child with the surrogate and the future parents. The subrogated motherhood was initially considered an option to solve infertility problems. Nevertheless this practice has become a possible and attractive option as a source of economic resources for poor women. The cases of benefit of a pregnancy without mediating a contract are exceptional and they are not properly cases of ″subrogated maternity″ but of ″altruistic maternity″ and must be considered as heterologous in vitro fertilization. In this article are analyzed the medical, genetic and bioethics aspects of this new derivation of the fertilization in vitro. As points of special attention are considered the following questions: Is it the surrogate motherhood used preferably to solve infertility problems? Is not this actually a new form of exploitation of the woman? Does not suppose an attack to the natural family? Does not suppose in addition an attack to the dignity of the human being?

  13. Effects of cultivation conditions on the uptake of arsenite and arsenic chemical species accumulated by Pteris vittata in hydroponics.

    Science.gov (United States)

    Hatayama, Masayoshi; Sato, Takahiko; Shinoda, Kozo; Inoue, Chihiro

    2011-03-01

    The physiological responses of the arsenic-hyperaccumulator, Pteris vittata, such as arsenic uptake and chemical transformation in the fern, have been investigated. However, a few questions remain regarding arsenic treatment in hydroponics. Incubation conditions such as aeration, arsenic concentration, and incubation period might affect those responses of P. vittata in hydroponics. Arsenite uptake was low under anaerobic conditions, as previously reported. However, in an arsenite uptake experiment, phosphorous (P) starvation-dependent uptake of arsenate was observed under aerobic conditions. Time course-dependent analysis of arsenite oxidation showed that arsenite was gradually oxidized to arsenate during incubation. Arsenite oxidation was not observed in any of the control conditions, such as exposure to a nutrient solution or to culture medium only, or with the use of dried root; arsenite oxidation was only observed when live root was used. This result suggests that sufficient aeration allows the rhizosphere system to oxidize arsenite and enables the fern to efficiently take up arsenite as arsenate. X-ray absorption near edge structure (XANES) analyses showed that long-duration exposure to arsenic using a hydroponic system led to the accumulation of arsenate as the dominant species in the root tips, but not in the whole roots, partly because up-regulation of arsenate uptake by P starvation of the fern was caused and retained by long-time incubation. Analysis of concentration-dependent arsenate uptake by P. vittata showed that the uptake switched from a high-affinity transport system to a low-affinity system at high arsenate concentrations, which partially explains the increased arsenate abundance in the whole root. Copyright © 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  14. Demonstration of Fast and Accurate Discrimination and Quantification of Chemically Similar Species Utilizing a Single Cross-Selective Chemiresistor

    Science.gov (United States)

    2015-01-01

    Performance characteristics of gas-phase microsensors will determine the ultimate utility of these devices for a wide range of chemical monitoring applications. Commonly employed chemiresistor elements are quite sensitive to selected analytes, and relatively new methods have increased the selectivity to specific compounds, even in the presence of interfering species. Here, we have focused on determining whether purposefully driven temperature modulation can produce faster sensor-response characteristics, which could enable measurements for a broader range of applications involving dynamic compositional analysis. We investigated the response speed of a single chemiresitive In2O3 microhotplate sensor to four analytes (methanol, ethanol, acetone, 2-butanone) by systematically varying the oscillating frequency (semicycle periods of 20–120 ms) of a bilevel temperature cycle applied to the sensing element. It was determined that the fastest response (≈ 9 s), as indicated by a 98% signal-change metric, occurred for a period of 30 ms and that responses under such modulation were dramatically faster than for isothermal operation of the same device (>300 s). Rapid modulation between 150 and 450 °C exerts kinetic control over transient processes, including adsorption, desorption, diffusion, and reaction phenomena, which are important for charge transfer occurring in transduction processes and the observed response times. We also demonstrate that the fastest operation is accompanied by excellent discrimination within a challenging 16-category recognition problem (consisting of the four analytes at four separate concentrations). This critical finding demonstrates that both speed and high discriminatory capabilities can be realized through temperature modulation. PMID:24931319

  15. Chemical Analysis and Biological Activity of the Essential Oils of Two Valerianaceous Species from China: Nardostachys chinensis and Valeriana officinalis

    Directory of Open Access Journals (Sweden)

    Jianglin Zhao

    2010-09-01

    Full Text Available In order to investigate essential oils with biological activity from local wild plants, two valerianaceous species, Nardostachys chinensis and Valeriana officinalis, were screened for their antimicrobial and antioxidant activity. The essential oils were obtained from the roots and rhizomes of the two plants by hydro-distillation, and were analyzed for their chemical composition by gas chromatography (GC and gas chromatography-mass spectrometry (GC-MS. Calarene (25.31%, aristolone (13.35%, α-selinene (7.32% and β-maaliene (6.70% were the major compounds of the 23 identified components which accounted for 92.76% of the total oil of N. chinensis. Patchoulol (16.75%, α-pinene (14.81%, and β-humulene (8.19% were the major compounds among the 20 identified components, which accounted for 88.11% of the total oil of V. officinalis. Both oils were rich in sesquiterpene hydrocarbons as well as their oxygenated derivatives. Essential oils were shown to have broad spectrum antibacterial activity with MIC values that ranged from 62.5 μg/mL to 400 μg/mL, and IC50 values from 36.93 μg/mL to 374.72 μg/mL. The oils were also shown to have moderate antifungal activity to Candida albicans growth as well as inhibition of spore germination of Magnaporthe oryzae. Two essential oils were assessed by 1,1-diphenyl-2-picrylhydrazyl (DPPH free radical scavenging, β-carotene bleaching and ferrozine-ferrous ions assays, respectively, to show moderate antioxidant activity. Results suggest that the isolated essential oils could be used for future development of antimicrobial and antioxidant agents.

  16. Cross talk between increased intracellular zinc (Zn2+) and accumulation of reactive oxygen species in chemical ischemia.

    Science.gov (United States)

    Slepchenko, Kira G; Lu, Qiping; Li, Yang V

    2017-10-01

    Both zinc (Zn 2+ ) and reactive oxygen species (ROS) have been shown to accumulate during hypoxic-ischemic stress and play important roles in pathological processes. To understand the cross talk between the two of them, here we studied Zn 2+ and ROS accumulation by employing fluorescent probes in HeLa cells to further the understanding of the cause and effect relationship of these two important cellular signaling systems during chemical-ischemia, stimulated by oxygen and glucose deprivation (OGD). We observed two Zn 2+ rises that were divided into four phases in the course of 30 min of OGD. The first Zn 2+ rise was a transient, which was followed by a latent phase during which Zn 2+ levels recovered; however, levels remained above a basal level in most cells. The final phase was the second Zn 2+ rise, which reached a sustained plateau called Zn 2+ overload. Zn 2+ rises were not observed when Zn 2+ was removed by TPEN (a Zn 2+ chelator) or thapsigargin (depleting Zn 2+ from intracellular stores) treatment, indicating that Zn 2+ was from intracellular storage. Damaging mitochondria with FCCP significantly reduced the second Zn 2+ rise, indicating that the mitochondrial Zn 2+ accumulation contributes to Zn 2+ overload. We also detected two OGD-induced ROS rises. Two Zn 2+ rises preceded two ROS rises. Removal of Zn 2+ reduced or delayed OGD- and FCCP-induced ROS generation, indicating that Zn 2+ contributes to mitochondrial ROS generation. There was a Zn 2+ -induced increase in the functional component of NADPH oxidase, p47 phox , thus suggesting that NADPH oxidase may mediate Zn 2+ -induced ROS accumulation. We suggest a new mechanism of cross talk between Zn 2+ and mitochondrial ROS through positive feedback processes that eventually causes excessive free Zn 2+ and ROS accumulations during the course of ischemic stress. Copyright © 2017 the American Physiological Society.

  17. Chemical characterization of 21 species of marine macroalgae common in Norwegian waters: benefits of and limitations to their potential use in food and feed

    Science.gov (United States)

    Biancarosa, Irene; Belghit, Ikram; Bruckner, Christian G; Liland, Nina S; Waagbø, Rune; Amlund, Heidi; Heesch, Svenja

    2018-01-01

    Abstract BACKGROUND In the past few years, much effort has been invested into developing a new blue economy based on harvesting, cultivating and processing marine macroalgae in Norway. Macroalgae have high potential for a wide range of applications, e.g. as source of pharmaceuticals, production of biofuels or as food and feed. However, data on the chemical composition of macroalgae from Norwegian waters are scant. This study was designed to characterize the chemical composition of 21 algal species. Both macro‐ and micronutrients were analysed. Concentrations of heavy metals and the metalloid arsenic in the algae were also quantified. RESULTS The results confirm that marine macroalgae contain nutrients which are relevant for both human and animal nutrition, the concentrations whereof are highly dependent on species. Although heavy metals and arsenic were detected in the algae studied, concentrations were mostly below maximum allowed levels set by food and feed legislation in the EU. CONCLUSION This study provides chemical data on a wide range of algal species covering the three taxonomic groups (brown, red and green algae) and discusses both benefits of and potential limitations to their use for food and feed purposes. © 2017 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:29193189

  18. A review of reaction rates and thermodynamic and transport properties for an 11-species air model for chemical and thermal nonequilibrium calculations to 30000 K

    Science.gov (United States)

    Gupta, Roop N.; Yos, Jerrold M.; Thompson, Richard A.; Lee, Kam-Pui

    1990-01-01

    Reaction rate coefficients and thermodynamic and transport properties are reviewed and supplemented for the 11-species air model which can be used for analyzing flows in chemical and thermal nonequilibrium up to temperatures of 3000 K. Such flows will likely occur around currently planned and future hypersonic vehicles. Guidelines for determining the state of the surrounding environment are provided. Curve fits are given for the various species properties for their efficient computation in flowfield codes. Approximate and more exact formulas are provided for computing the properties of partially ionized air mixtures in a high energy environment. Limitations of the approximate mixing laws are discussed for a mixture of ionized species. An electron number-density correction for the transport properties of the charged species is obtained. This correction has been generally ignored in the literature.

  19. A new formulation of physical surrogates of FACE A gasoline fuel based on heating and evaporation characteristics

    KAUST Repository

    Elwardani, Ahmed Elsaid; Sazhin, S.S.; Im, Hong G.

    2016-01-01

    The US Department of Energy has formulated various sets of gasoline fuels, called fuels for advanced combustion engines (FACE), which are consistent in composition and properties. The analysis of heating and evaporation of FACE A gasoline fuel (paraffin-rich) is studied by replacing the 66 components with 19 components to represent this fuel. The reduction in the number of components is based on merging components from the same chemical groups and having the same chemical formula, which have very close thermophysical properties; the components with the highest initial compositions are chosen to be the representative components. Modelling of heating and evaporation of FACE A gasoline fuel and various surrogates is carried out based on the effective thermal conductivity/effective diffusivity model (ETC/ED). The model takes into account the effect of finite liquid thermal conductivity, finite liquid mass diffusivity and recirculation inside the droplets due to their non-zero velocities relative to the ambient air. Four surrogates of FACE A found in the literature are used in the analysis. These surrogates include the five component surrogate chosen for its ability to match the ignition delay time of the FACE A gasoline fuel (Surr1), the primary reference fuel surrogate (PRF84) that matches the research octane number (RON) of FACE A, the one that matches hydrogen-to-carbon ratio (H/C), RON, density and distillation curve with FACE A (Surr2), and the one that matches the RON based on mole fraction linear blending (Surr3). It is shown that these surrogates cannot predict adequately the time evolution of surface temperatures and radii of FACE A droplets. New 'physical' surrogates with 8, 7 and 6 components (Surr4, Surr5, and Surr6) are introduced to match the evaporation characteristics of FACE A. It is found that Surr5 (7 components surrogate) can predict droplet lifetime and time evolution of surface temperature of a FACE A droplet with errors of up to 5% and 0

  20. A new formulation of physical surrogates of FACE A gasoline fuel based on heating and evaporation characteristics

    KAUST Repository

    Elwardani, Ahmed Elsaid

    2016-02-19

    The US Department of Energy has formulated various sets of gasoline fuels, called fuels for advanced combustion engines (FACE), which are consistent in composition and properties. The analysis of heating and evaporation of FACE A gasoline fuel (paraffin-rich) is studied by replacing the 66 components with 19 components to represent this fuel. The reduction in the number of components is based on merging components from the same chemical groups and having the same chemical formula, which have very close thermophysical properties; the components with the highest initial compositions are chosen to be the representative components. Modelling of heating and evaporation of FACE A gasoline fuel and various surrogates is carried out based on the effective thermal conductivity/effective diffusivity model (ETC/ED). The model takes into account the effect of finite liquid thermal conductivity, finite liquid mass diffusivity and recirculation inside the droplets due to their non-zero velocities relative to the ambient air. Four surrogates of FACE A found in the literature are used in the analysis. These surrogates include the five component surrogate chosen for its ability to match the ignition delay time of the FACE A gasoline fuel (Surr1), the primary reference fuel surrogate (PRF84) that matches the research octane number (RON) of FACE A, the one that matches hydrogen-to-carbon ratio (H/C), RON, density and distillation curve with FACE A (Surr2), and the one that matches the RON based on mole fraction linear blending (Surr3). It is shown that these surrogates cannot predict adequately the time evolution of surface temperatures and radii of FACE A droplets. New \\'physical\\' surrogates with 8, 7 and 6 components (Surr4, Surr5, and Surr6) are introduced to match the evaporation characteristics of FACE A. It is found that Surr5 (7 components surrogate) can predict droplet lifetime and time evolution of surface temperature of a FACE A droplet with errors of up to 5% and 0

  1. Effectiveness of amphibians as biodiversity surrogates in pond conservation.

    Science.gov (United States)

    Ilg, Christiane; Oertli, Beat

    2017-04-01

    Amphibian decline has led to worldwide conservation efforts, including the identification and designation of sites for their protection. These sites could also play an important role in the conservation of other freshwater taxa. In 89 ponds in Switzerland, we assessed the effectiveness of amphibians as a surrogate for 4 taxonomic groups that occur in the same freshwater ecosystems as amphibians: dragonflies, aquatic beetles, aquatic gastropods, and aquatic plants. The ponds were all of high value for amphibian conservation. Cross-taxon correlations were tested for species richness and conservation value, and Mantel tests were used to investigate community congruence. Species richness, conservation value, and community composition of amphibians were weakly congruent with these measures for the other taxonomic groups. Paired comparisons for the 5 groups considered showed that for each metric, amphibians had the lowest degree of congruence. Our results imply that site designation for amphibian conservation will not necessarily provide protection for freshwater biodiversity as a whole. To provide adequate protection for freshwater species, we recommend other taxonomic groups be considered in addition to amphibians in the prioritization and site designation process. © 2016 Society for Conservation Biology.

  2. Habitats as surrogates of taxonomic and functional fish assemblages in coral reef ecosystems: a critical analysis of factors driving effectiveness.

    Directory of Open Access Journals (Sweden)

    Simon Van Wynsberge

    Full Text Available Species check-lists are helpful to establish Marine Protected Areas (MPAs and protect local richness, endemicity, rarity, and biodiversity in general. However, such exhaustive taxonomic lists (i.e., true surrogate of biodiversity require extensive and expensive censuses, and the use of estimator surrogates (e.g., habitats is an appealing alternative. In truth, surrogate effectiveness appears from the literature highly variable both in marine and terrestrial ecosystems, making it difficult to provide practical recommendations for managers. Here, we evaluate how the biodiversity reference data set and its inherent bias can influence effectiveness. Specifically, we defined habitats by geomorphology, rugosity, and benthic cover and architecture criteria, and mapped them with satellite images for a New-Caledonian site. Fish taxonomic and functional lists were elaborated from Underwater Visual Censuses, stratified according to geomorphology and exposure. We then tested if MPA networks designed to maximize habitat richness, diversity and rarity could also effectively maximize fish richness, diversity, and rarity. Effectiveness appeared highly sensitive to the fish census design itself, in relation to the type of habitat map used and the scale of analysis. Spatial distribution of habitats (estimator surrogate's distribution, quantity and location of fish census stations (target surrogate's sampling, and random processes in the MPA design all affected effectiveness to the point that one small change in the data set could lead to opposite conclusions. We suggest that previous conclusions on surrogacy effectiveness, either positive or negative, marine or terrestrial, should be considered with caution, except in instances where very dense data sets were used without pseudo-replication. Although this does not rule out the validity of using surrogates of species lists for conservation planning, the critical joint examination of both target and estimator

  3. Chromatographic speciation of Cr(III)-species, inter-species equilibrium isotope fractionation and improved chemical purification strategies for high-precision isotope analysis

    DEFF Research Database (Denmark)

    Larsen, Kirsten Kolbjørn; Wielandt, Daniel Kim Peel; Schiller, Martin

    2016-01-01

    Chromatographic purification of chromium (Cr), which is required for high-precision isotope analysis, is complicated by the presence of multiple Cr-species with different effective charges in the acid digested sample aliquots. The differing ion exchange selectivity and sluggish reaction rates of ...

  4. Surrogate pregnancy: a guide for Canadian prenatal health care providers

    OpenAIRE

    Reilly, Dan R.

    2007-01-01

    Providing health care for a woman with a surrogate pregnancy involves unique challenges. Although the ethical debate surrounding surrogacy continues, Canada has banned commercial, but not altruistic, surrogacy. In the event of a custody dispute between a surrogate mother and the individual(s) intending to parent the child, it is unclear how Canadian courts would rule. The prenatal health care provider must take extra care to protect the autonomy and privacy rights of the surrogate. There is l...

  5. Influence of soil physical and chemical variables on species composition and richness of plants in the arid region of Tabuk, Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Al-Mutairi Khalid Awadh

    2017-06-01

    Full Text Available The present study aims to investigate the effect of soil physical and chemical variables on the species richness and the floristic composition in four sites (Alwaz, Alqan, Sharma and Zetah of Tabuk region in the Northwestern part of Arabian Peninsula. Only organic matter (OM, pH and calcium (Ca showed significant differences (P < 0.05 amongst the four studied sites. Only magnesium and sodium were selected in the forward regression model and showed to be strong drivers of species richness of plants in Tabuk region (Adj-R2 = 0.438, F2,13 = 6.85, P = 0.009. The multivariate analysis of canonical correspondence analysis (CCA was applied to reveal the effect of the physical and chemical variables on the species composition of the plants. The CCA classifies the plant species into three groups based on their preference to the environmental variables. The first group of plant species (Group 1 is characterised by positive preference to the chloride (Cl and negative relationship with OM and pH. The second group (Group 2 is positively correlated with most of the soil variables such as OM, calcium (Ca, potassium (K, bicarbonate (HCO3, electrical conductivity (EC, sulphate (SO4 and sodium (Na. The third group (Group 3 has positive relationship with carbonate (CO3 and negative relationship with EC and magnesium (Mg. The chloride, sodium, sulphate, EC and carbonate are the main environmental factors influencing the plant species composition in Tabuk region. The cluster analysis based on the Euclidian measure shows that Alqan and Zetah have closer species composition compared to Sharma.

  6. A review of reaction rates and thermodynamic and transport properties for the 11-species air model for chemical and thermal nonequilibrium calculations to 30000 K

    Science.gov (United States)

    Gupta, Roop N.; Yos, Jerrold M.; Thompson, Richard A.

    1989-01-01

    Reaction rate coefficients and thermodynamic and transport properties are provided for the 11-species air model which can be used for analyzing flows in chemical and thermal nonequilibrium. Such flows will likely occur around currently planned and future hypersonic vehicles. Guidelines for determining the state of the surrounding environment are provided. Approximate and more exact formulas are provided for computing the properties of partially ionized air mixtures in such environments.

  7. The Rules of Aggression: How Genetic, Chemical and Spatial Factors Affect Intercolony Fights in a Dominant Species, the Mediterranean Acrobat Ant Crematogaster scutellaris.

    Directory of Open Access Journals (Sweden)

    Filippo Frizzi

    Full Text Available Nest-mate recognition plays a key role in the biology of ants. Although individuals coming from a foreign nest are, in most cases, promptly rejected, the degree of aggressiveness towards non nest-mates may be highly variable among species and relies on genetic, chemical and environmental factors. We analyzed intraspecific relationships among neighboring colonies of the dominant Mediterranean acrobat ant Crematogaster scutellaris integrating genetic, chemical and behavioral analyses. Colony structure, parental relationships between nests, cuticular hydrocarbons profiles (CHCs and aggressive behavior against non nest-mates were studied in 34 nests located in olive tree trunks. Bayesian clustering analysis of allelic variation at nine species-specific microsatellite DNA markers pooled nests into 14 distinct clusters, each representing a single colony, confirming a polydomous arrangement of nests in this species. A marked genetic separation among colonies was also detected, probably due to long distance dispersion of queens and males during nuptial flights. CHCs profiles varied significantly among colonies and between nests of the same colony. No relationship between CHCs profiles and genetic distances was detected. The level of aggressiveness between colonies was inversely related to chemical and spatial distance, suggesting a 'nasty neighbor' effect. Our findings also suggest that CHCs profiles in C. scutellaris may be linked to external environmental factors rather than genetic relationships.

  8. Comparison of tropical and temperate freshwater animal species' acute sensitivities to chemicals: implications for deriving safe extrapolation factors

    NARCIS (Netherlands)

    Kwok, K.W.H.; Leung, K.M.Y.; Lui, G.S.G.; Chu, V.K.H.; Lam, P.K.S.; Morritt, D.; Maltby, L.; Brock, T.C.M.; Brink, van den P.J.; Warne, M.S.J.; Crane, M.

    2007-01-01

    Toxicity data for tropical species are often lacking for ecological risk assessment. Consequently, tropical and subtropical countries use water quality criteria (WQC) derived from temperate species (e.g., United States, Canada, or Europe) to assess ecological risks in their aquatic systems, leaving

  9. Plasma-activation of tap water using DBD for agronomy applications: Identification and quantification of long lifetime chemical species and production/consumption mechanisms.

    Science.gov (United States)

    Judée, F; Simon, S; Bailly, C; Dufour, T

    2018-04-15

    Cold atmospheric plasmas are weakly ionized gases that can be generated in ambient air. They produce energetic species (e.g. electrons, metastables) as well as reactive oxygen species, reactive nitrogen species, UV radiations and local electric field. Their interaction with a liquid such as tap water can hence change its chemical composition. The resulting "plasma-activated liquid" can meet many applications, including medicine and agriculture. Consequently, a complete experimental set of analytical techniques dedicated to the characterization of long lifetime chemical species has been implemented to characterize tap water treated using cold atmospheric plasma process and intended to agronomy applications. For that purpose, colorimetry and acid titrations are performed, considering acid-base equilibria, pH and temperature variations induced during plasma activation. 16 species are quantified and monitored: hydroxide and hydronium ions, ammonia and ammonium ions, orthophosphates, carbonate ions, nitrite and nitrate ions and hydrogen peroxide. The related consumption/production mechanisms are discussed. In parallel, a chemical model of electrical conductivity based on Kohlrausch's law has been developed to simulate the electrical conductivity of the plasma-activated tap water (PATW). Comparing its predictions with experimental measurements leads to a narrow fitting, hence supporting the self-sufficiency of the experimental set, I.e. the fact that all long lifetime radicals of interest present in PATW are characterized. Finally, to evaluate the potential of cold atmospheric plasmas for agriculture applications, tap water has been daily plasma-treated to irrigate lentils seeds. Then, seedlings lengths have been measured and compared with untreated tap water, showing an increase as high as 34.0% and 128.4% after 3 days and 6 days of activation respectively. The interaction mechanisms between plasma and tap water are discussed as well as their positive synergy on

  10. Airfoil Shape Optimization based on Surrogate Model

    Science.gov (United States)

    Mukesh, R.; Lingadurai, K.; Selvakumar, U.

    2018-02-01

    Engineering design problems always require enormous amount of real-time experiments and computational simulations in order to assess and ensure the design objectives of the problems subject to various constraints. In most of the cases, the computational resources and time required per simulation are large. In certain cases like sensitivity analysis, design optimisation etc where thousands and millions of simulations have to be carried out, it leads to have a life time of difficulty for designers. Nowadays approximation models, otherwise called as surrogate models (SM), are more widely employed in order to reduce the requirement of computational resources and time in analysing various engineering systems. Various approaches such as Kriging, neural networks, polynomials, Gaussian processes etc are used to construct the approximation models. The primary intention of this work is to employ the k-fold cross validation approach to study and evaluate the influence of various theoretical variogram models on the accuracy of the surrogate model construction. Ordinary Kriging and design of experiments (DOE) approaches are used to construct the SMs by approximating panel and viscous solution algorithms which are primarily used to solve the flow around airfoils and aircraft wings. The method of coupling the SMs with a suitable optimisation scheme to carryout an aerodynamic design optimisation process for airfoil shapes is also discussed.

  11. Compositional effects on PAH and soot formation in counterflow diffusion flames of gasoline surrogate fuels

    KAUST Repository

    Park, Sungwoo

    2017-02-05

    Gasoline surrogate fuels are widely used to understand the fundamental combustion properties of complex refinery gasoline fuels. In this study, the compositional effects on polycyclic aromatic hydrocarbons (PAHs) and soot formation were investigated experimentally for gasoline surrogate mixtures comprising n-heptane, iso-octane, and toluene in counterflow diffusion flames. A comprehensive kinetic model for the gasoline surrogate mixtures was developed to accurately predict the fuel oxidation along with the formation of PAHs and soot in flames. This combined model was first tested against ignition delay times and laminar burning velocities data. The proposed model for the formation and growth of PAHs up to coronene (C24H12) was based on previous studies and was tested against existing and present new experimental data. Additionally, in the accompanied soot model, PAHs with sizes larger than (including) pyrene were used for the inception of soot particles, followed by particle coagulations and PAH condensation/chemical reactions on soot surfaces. The major pathways for the formation of PAHs were also identified for the surrogate mixtures. The model accurately captures the synergistic PAH formation characteristics observed experimentally for n-heptane/toluene and iso-octane/toluene binary mixtures. Furthermore, the present experimental and modeling results also elucidated different trends in the formation of larger PAHs and soot between binary n-heptane/iso-octane and ternary n-heptane/iso-octane/toluene mixtures. Propargyl radicals (C3H3) were shown to be important in the formation and growth of PAHs for n-heptane/iso-octane mixtures when the iso-octane concentration increased; however, reactions involving benzyl radicals (C6H5CH2) played a significant role in the formation of PAHs for n-heptane/iso-octane/toluene mixtures. These results indicated that the formation of PAHs and subsequently soot was strongly affected by the composition of gasoline surrogate mixtures.

  12. Compositional effects on PAH and soot formation in counterflow diffusion flames of gasoline surrogate fuels

    KAUST Repository

    Park, Sungwoo; Wang, Yu; Chung, Suk-Ho; Sarathy, Mani

    2017-01-01

    Gasoline surrogate fuels are widely used to understand the fundamental combustion properties of complex refinery gasoline fuels. In this study, the compositional effects on polycyclic aromatic hydrocarbons (PAHs) and soot formation were investigated experimentally for gasoline surrogate mixtures comprising n-heptane, iso-octane, and toluene in counterflow diffusion flames. A comprehensive kinetic model for the gasoline surrogate mixtures was developed to accurately predict the fuel oxidation along with the formation of PAHs and soot in flames. This combined model was first tested against ignition delay times and laminar burning velocities data. The proposed model for the formation and growth of PAHs up to coronene (C24H12) was based on previous studies and was tested against existing and present new experimental data. Additionally, in the accompanied soot model, PAHs with sizes larger than (including) pyrene were used for the inception of soot particles, followed by particle coagulations and PAH condensation/chemical reactions on soot surfaces. The major pathways for the formation of PAHs were also identified for the surrogate mixtures. The model accurately captures the synergistic PAH formation characteristics observed experimentally for n-heptane/toluene and iso-octane/toluene binary mixtures. Furthermore, the present experimental and modeling results also elucidated different trends in the formation of larger PAHs and soot between binary n-heptane/iso-octane and ternary n-heptane/iso-octane/toluene mixtures. Propargyl radicals (C3H3) were shown to be important in the formation and growth of PAHs for n-heptane/iso-octane mixtures when the iso-octane concentration increased; however, reactions involving benzyl radicals (C6H5CH2) played a significant role in the formation of PAHs for n-heptane/iso-octane/toluene mixtures. These results indicated that the formation of PAHs and subsequently soot was strongly affected by the composition of gasoline surrogate mixtures.

  13. Microspectroscopic imaging of solution plasma: How do its physical properties and chemical species evolve in atmospheric-pressure water vapor bubbles?

    Science.gov (United States)

    Yui, Hiroharu; Banno, Motohiro

    2018-01-01

    In this article, we review the development of scientific instruments for obtaining information on the evolution of physical properties and chemical species of solution plasma (SP). When a pulsed high voltage is applied between electrodes immersed in an aqueous solution, SP is formed in water vapor bubbles transiently generated in the solution under atmospheric pressure. To clarify how SP emerges in water vapor bubbles and is sustained in solutions, an instrument with micrometer spatial resolution and nanosecond temporal resolution is required. To meet these requirements, a microscopic system with a custom-made optical discharge cell was newly developed, where the working distance between the SP and the microscopic objective lens was minimized. A hollow electrode equipped in the discharge cell also enabled us to control the chemical composition in water vapor bubbles. To study the spatial and temporal evolutions of chemical species in micrometer and nano- to microsecond regions, a streak camera with a spectrometer and a CCD detector with a time-gated electronic device were combined with the microscope system. The developed instrument is expected to contribute to providing a new means of developing new schemes for chemical reactions and material syntheses.

  14. Use of chemical elements of 1A family by tropical tree species; Uso de elementos quimicos da familia 1A por especies arboreas tropicais

    Energy Technology Data Exchange (ETDEWEB)

    Carmo, Andrius M.J.; Paiva, Jose Daniel S. de; Magalhaes, Marcelo R.L. de; Franca, Elvis J. de; Hazin, Clovis A., E-mail: ejfranca@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Bacchi, Marcio A.; Fernandes, Elisabete A.N., E-mail: mabacchi@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil).

    2013-07-01

    This study aims to evaluate the distribution of K, Rb and Cs in leaves of trees of the Atlantic Forest through studies of correlation between the chemical elements. For this, we used the Instrumental Neutron Activation Analysis for the quantification of the chemical elements. The concentration ranges found were 6700-24000 mg / kg for K, 16 to 72mg / kg for Rb and 0.08 to 0,92mg / kg for Cs. As Rb has chemical similarity to K, is easily absorbed by plants, leading to a high value (0.9) of the Pearson correlation. For the correlation between K and Cs, no significant values were detected except for some species of the Myrtaceae family. However, average correlations (0.6 species of different families. The absence of a specific pattern using of K, Rb and Cs by plants showed great complexity in the distribution of chemical elements in the ecosystem.

  15. Assessment of pollution along the Northern Iberian shelf by the combined use of chemical and biochemical markers in two representative fish species

    International Nuclear Information System (INIS)

    Fernandes, Denise; Andreu-Sanchez, Oscar; Bebianno, Maria Joao; Porte, Cinta

    2008-01-01

    Muscle concentrations of organochlorinated compounds as well as biliary levels of polycyclic aromatic hydrocarbons (PAHs) and alkylphenols (APEs) were determined in two different fish species, the four-spotted megrim (Lepidorhombus boscii) and the pouting (Trisopterus luscus) collected along the Northern Iberian coast. Additionally, a set of biochemical markers namely, 7-ethoxyresorufin O-deethylase (EROD), UDP-glucuronosyltransferase (UGT) and catalase (CAT) were measured in liver subcellular fractions. Chemical analysis indicated geographical differences in pollutant loads that were further reinforced by biomarker responses. Thus, EROD activity showed a good correlation with the amount of PCBs bioaccumulated in muscle tissue of both fish species. Elevated UGT activity was observed in those individuals highly exposed to APEs and 1-naphthol. The study reinforces the need to select representative sentinel species from different habitats for biomonitoring purposes and provides further support for the use of biomarkers in assessing the health of coastal areas. - Pollution biomonitoring along the Northern Iberian Shelf by the combined use of chemical and biochemical tools in two representative fish species

  16. Assessment of pollution along the Northern Iberian shelf by the combined use of chemical and biochemical markers in two representative fish species

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Denise [CIMA, University of Algarve, FCMA, Campus de Gambelas, 8005-139 Faro (Portugal); Department of Environmental Chemistry, IIQAB-CSIC, Jordi Girona 18, 08034 Barcelona (Spain); Andreu-Sanchez, Oscar [Polytechnic University Valencia, E.T.S.I. Agronomy, Biotechnology Department, 46022, Valencia (Spain); Bebianno, Maria Joao [CIMA, University of Algarve, FCMA, Campus de Gambelas, 8005-139 Faro (Portugal); Porte, Cinta [Department of Environmental Chemistry, IIQAB-CSIC, Jordi Girona 18, 08034 Barcelona (Spain)], E-mail: cpvqam@cid.csic.es

    2008-09-15

    Muscle concentrations of organochlorinated compounds as well as biliary levels of polycyclic aromatic hydrocarbons (PAHs) and alkylphenols (APEs) were determined in two different fish species, the four-spotted megrim (Lepidorhombus boscii) and the pouting (Trisopterus luscus) collected along the Northern Iberian coast. Additionally, a set of biochemical markers namely, 7-ethoxyresorufin O-deethylase (EROD), UDP-glucuronosyltransferase (UGT) and catalase (CAT) were measured in liver subcellular fractions. Chemical analysis indicated geographical differences in pollutant loads that were further reinforced by biomarker responses. Thus, EROD activity showed a good correlation with the amount of PCBs bioaccumulated in muscle tissue of both fish species. Elevated UGT activity was observed in those individuals highly exposed to APEs and 1-naphthol. The study reinforces the need to select representative sentinel species from different habitats for biomonitoring purposes and provides further support for the use of biomarkers in assessing the health of coastal areas. - Pollution biomonitoring along the Northern Iberian Shelf by the combined use of chemical and biochemical tools in two representative fish species.

  17. Toxicity and utilization of chemical weapons: does toxicity and venom utilization contribute to the formation of species communities?

    Science.gov (United States)

    Westermann, Fabian L; McPherson, Iain S; Jones, Tappey H; Milicich, Lesley; Lester, Philip J

    2015-08-01

    Toxicity and the utilization of venom are essential features in the ecology of many animal species and have been hypothesized to be important factors contributing to the assembly of communities through competitive interactions. Ants of the genus Monomorium utilize a variety of venom compositions, which have been reported to give them a competitive advantage. Here, we investigate two pairs of Monomorium species, which differ in the structural compositions of their venom and their co-occurrence patterns with the invasive Argentine ant. We looked at the effects of Monomorium venom toxicity, venom utilization, and aggressive physical interactions on Monomorium and Argentine ant survival rates during arena trials. The venom toxicity of the two species co-occurring with the invasive Argentine ants was found to be significantly higher than the toxicity of the two species which do not. There was no correlation between venom toxicity and Monomorium survival; however, three of the four Monomorium species displayed significant variability in their venom usage which was associated with the number of Argentine ant workers encountered during trials. Average Monomorium mortality varied significantly between species, and in Monomorium smithii and Monomorium antipodum, aggressive interactions with Argentine ants had a significant negative effect on their mortality. Our study demonstrates that different factors and strategies can contribute to the ability of a species to withstand the pressure of a dominant invader at high abundance, and venom chemistry appears to be only one of several strategies utilized.

  18. The effects of wood storage on the chemical composition and indigenous microflora of eucalyptus species used in the pulping industry

    CSIR Research Space (South Africa)

    Ramnath, L

    2018-02-01

    Full Text Available Lipophilic extractives naturally occurring in wood tend to coalesce during pulping to form pitch deposits, which have particularly undesirable effects on the pulping process and quality of pulp produced. A chemical characterization of different...

  19. High-performance metabolic profiling of plasma from seven mammalian species for simultaneous environmental chemical surveillance and bioeffect monitoring

    OpenAIRE

    Park, Youngja H.; Lee, Kichun; Soltow, Quinlyn A.; Strobel, Frederick H.; Brigham, Kenneth L.; Parker, Richard E.; Wilson, Mark E.; Sutliff, Roy L.; Mansfield, Keith G.; Wachtman, Lynn M.; Ziegler, Thomas R.; Jones, Dean P.

    2012-01-01

    High-performance metabolic profiling (HPMP) by Fourier-transform mass spectrometry coupled to liquid chromatography gives relative quantification of thousands of chemicals in biologic samples but has had little development for use in toxicology research. In principle, the approach could be useful to detect complex metabolic response patterns to toxicologic exposures and to detect unusual abundances or patterns of potentially toxic chemicals. As an initial study to develop these possible uses,...

  20. Steam sauna and mother roasting in Lao PDR: practices and chemical constituents of essential oils of plant species used in postpartum recovery

    Science.gov (United States)

    2011-01-01

    Background Fundamental in traditional postpartum recovery in Lao PDR is the use of hotbeds, mother roasting, steam sauna and steam baths. During these treatments medicinal plants play a crucial role, but little has been published about how the treatments are carried out precisely, which species are used, the medicinal properties of these species, and the medicinal efficacy of their chemical constituents. Methods Sixty-five interviews, in 15 rural villages, with women of 4 different ethnic groups were conducted to survey confinement rituals, and postpartum plant use and salience. Essential oils from the main species used were extracted using steam distillation and the main chemical constituents characterized using gas chromatography-mass spectrometry (GC-MS). Results A total of 10 different species were used by three or more of the ethnic groups included in this study. All species were used in steam sauna and bath, but only 3 species were used in hotbed and mother roasting. Essential oils of Amomum villosum, Amomum microcarpum and Blumea balsamifera were found to contain significant amounts of the following terpenes: β-pinene, camphor, bornyl acetate, borneol, linalool, D-limonene, fenchone, terpinen-4-ol and α-terpinene. Conclusions Many of these terpenes have documented antimicrobial and analgesic properties, and some have also synergistic interactions with other terpenes. The mode of application in hotbed and mother roasting differs from the documented mechanisms of action of these terpenes. Plants in these two practices are likely to serve mainly hygienic purposes, by segregating the mother from infection sources such as beds, mats, stools, cloth and towels. Steam sauna medicinal plant use through inhalation of essential oils vapors can possibly have medicinal efficacy, but is unlikely to alleviate the ailments commonly encountered during postpartum convalescence. Steam sauna medicinal plant use through dermal condensation of essential oils, and steam bath

  1. SOA formation from photooxidation of naphthalene and methylnaphthalenes with m-xylene and surrogate mixtures

    Science.gov (United States)

    Chen, Chia-Li; Li, Lijie; Tang, Ping; Cocker, David R.

    2018-05-01

    SOA formation is not well predicted in current models in urban area. The interaction among multiple anthropogenic volatile organic compounds is essential for the SOA formation in the complex urban atmosphere. Secondary organic aerosol (SOA) from the photooxidation of naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene as well as individual polycyclic aromatic hydrocarbons (PAHs) mixed with m-xylene or an atmospheric surrogate mixture was explored in the UCR CE-CERT environmental chamber under urban relevant low NOx and extremely low NOx (H2O2) conditions. Addition of m-xylene suppressed SOA formation from the individual PAH precursor. A similar suppression effect on SOA formation was observed during the surrogate mixture photooxidation suggesting the importance of gas-phase chemical reactivity to SOA formation. The SOA growth rate for different PAH-m-xylene mixtures was strongly correlated with initial [HO2]/[RO2] ratio but negatively correlated with initial m-xylene/NO ratio. Decreasing SOA formation was observed for increasing m-xylene/PAHs ratios and increasing initial m-xylene/NO ratio. The SOA chemical composition characteristics such as f44 versus f43, H/C ratio, O/C ratio, and the oxidation state of the carbon OSbarc were consistent with a continuously aging with the SOA exhibiting characteristics of both individual precursors. SOA formation from PAHs was also suppressed within an atmospheric surrogate mixture compared to the SOA formed from individual PAHs, indicating that atmospheric reactivity directly influences SOA formation from PAHs.

  2. Assessment of the reduction methods used to develop chemical schemes: building of a new chemical scheme for VOC oxidation suited to three-dimensional multiscale HOx-NOx-VOC chemistry simulations

    Directory of Open Access Journals (Sweden)

    S. Szopa

    2005-01-01

    Full Text Available The objective of this work was to develop and assess an automatic procedure to generate reduced chemical schemes for the atmospheric photooxidation of volatile organic carbon (VOC compounds. The procedure is based on (i the development of a tool for writing the fully explicit schemes for VOC oxidation (see companion paper Aumont et al., 2005, (ii the application of several commonly used reduction methods to the fully explicit scheme, and (iii the assessment of resulting errors based on direct comparison between the reduced and full schemes. The reference scheme included seventy emitted VOCs chosen to be representative of both anthropogenic and biogenic emissions, and their atmospheric degradation chemistry required more than two million reactions among 350000 species. Three methods were applied to reduce the size of the reference chemical scheme: (i use of operators, based on the redundancy of the reaction sequences involved in the VOC oxidation, (ii grouping of primary species having similar reactivities into surrogate species and (iii grouping of some secondary products into surrogate species. The number of species in the final reduced scheme is 147, this being small enough for practical inclusion in current three-dimensional models. Comparisons between the fully explicit and reduced schemes, carried out with a box model for several typical tropospheric conditions, showed that the reduced chemical scheme accurately predicts ozone concentrations and some other aspects of oxidant chemistry for both polluted and clean tropospheric conditions.

  3. Comparison of the chemical composition of three species of smartweed (genus Persicaria) with a focus on drimane sesquiterpenoids

    NARCIS (Netherlands)

    Prota, N.; Mumm, R.; Bouwmeester, H.J.; Jongsma, M.A.

    2014-01-01

    The genus Persicaria is known to include species accumulating drimane sesquiterpenoids, but a comparative analysis highlighting the compositional differences has not been done. In this study, the secondary metabolites of both flowers and leaves of Persicaria hydropiper, Persicaria maculosa and

  4. Chemical and biological study of essential oils from Eugenia pruniformis cambess., an endemic species from Brazilian Atlantic Forest

    OpenAIRE

    Albuquerque, Ricardo D.D.G.; Tietbohl, Luis A. C.; Fernandes, Caio P.; Couteiro, Pedro P.; Eiriz, Débora N.; Santos, Marcelo G.; Silva Filho, Moacélio V.; Alves, Gutemberg G.; Bachinski, Róber; Rocha, Leandro

    2012-01-01

    Eugenia pruniformis Cambess. is an endemic species from Brazilian Atlantic Forest. Essential oils from leaves and fruits from this species were obtained by hydrodistillation and analyzed by GCMS/CG-FID. In all, 25 compounds were identified, with predominance of sesquiterpene hydrocarbons in both plant parts. The major compounds were β-caryophyllene, bicyclogermacrene, germacrene D, δ- cadinene and α-copaene. Antioxidant activity was performed for essential oil from leaves using ORAC method, s...

  5. PLAN-TA9-2443(U), Rev. B Remediated Nitrate Salt (RNS) Surrogate Formulation and Testing Standard Procedure

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Geoffrey Wayne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-16

    This document identifies scope and some general procedural steps for performing Remediated Nitrate Salt (RNS) Surrogate Formulation and Testing. This Test Plan describes the requirements, responsibilities, and process for preparing and testing a range of chemical surrogates intended to mimic the energetic response of waste created during processing of legacy nitrate salts. The surrogates developed are expected to bound1 the thermal and mechanical sensitivity of such waste, allowing for the development of process parameters required to minimize the risk to worker and public when processing this waste. Such parameters will be based on the worst-case kinetic parameters as derived from APTAC measurements as well as the development of controls to mitigate sensitivities that may exist due to friction, impact, and spark. This Test Plan will define the scope and technical approach for activities that implement Quality Assurance requirements relevant to formulation and testing.

  6. Distinguishing Vaccinium species by chemical fingerprinting based on NMR spectra, validated with spectra collected in different laboratories.

    Science.gov (United States)

    Markus, Michelle A; Ferrier, Jonathan; Luchsinger, Sarah M; Yuk, Jimmy; Cuerrier, Alain; Balick, Michael J; Hicks, Joshua M; Killday, K Brian; Kirby, Christopher W; Berrue, Fabrice; Kerr, Russell G; Knagge, Kevin; Gödecke, Tanja; Ramirez, Benjamin E; Lankin, David C; Pauli, Guido F; Burton, Ian; Karakach, Tobias K; Arnason, John T; Colson, Kimberly L

    2014-06-01

    A method was developed to distinguish Vaccinium species based on leaf extracts using nuclear magnetic resonance spectroscopy. Reference spectra were measured on leaf extracts from several species, including lowbush blueberry (Vaccinium angustifolium), oval leaf huckleberry (Vaccinium ovalifolium), and cranberry (Vaccinium macrocarpon). Using principal component analysis, these leaf extracts were resolved in the scores plot. Analysis of variance statistical tests demonstrated that the three groups differ significantly on PC2, establishing that the three species can be distinguished by nuclear magnetic resonance. Soft independent modeling of class analogies models for each species also showed discrimination between species. To demonstrate the robustness of nuclear magnetic resonance spectroscopy for botanical identification, spectra of a sample of lowbush blueberry leaf extract were measured at five different sites, with different field strengths (600 versus 700 MHz), different probe types (cryogenic versus room temperature probes), different sample diameters (1.7 mm versus 5 mm), and different consoles (Avance I versus Avance III). Each laboratory independently demonstrated the linearity of their NMR measurements by acquiring a standard curve for chlorogenic acid (R(2) = 0.9782 to 0.9998). Spectra acquired on different spectrometers at different sites classifed into the expected group for the Vaccinium spp., confirming the utility of the method to distinguish Vaccinium species and demonstrating nuclear magnetic resonance fingerprinting for material validation of a natural health product. Georg Thieme Verlag KG Stuttgart · New York.

  7. Chemical characterization of organic aerosol above a mid-latitude forest reveals a complex mixture of highly-functionalized chemical species and diverse structural features with temporal variability

    Science.gov (United States)

    Gentner, D. R.; Ditto, J.; Barnes, E.; Khare, P.

    2017-12-01

    Highly-functionalized organic compounds are known to be a major component of the complex mixture of the particle-phase compounds that comprise organic aerosol, yet little is known about the identity of many of these compounds, and their formation pathways and roles in atmospheric processes are poorly understood. We present results from the comprehensive chemical speciation of PM10 organic aerosols collected in July 2016 at the remote mid-latitude forest field site during PROPHET. Samples were analyzed via liquid and gas chromatography coupled with a quadrupole time-of-flight tandem mass spectrometry (MS×MS) following electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI). 8 hr samples were collected during day- and night-time sampling periods rather than more typical 24-hour samples. This analysis of the organic aerosol yielded over 12,000 unique compounds for which we have high accuracy molecular masses, formulas, and additional information on structural features using MS×MS. O:C ratios were 0.3 on average, yet the top 10% of compounds ranged 0.7-2.3. 70% and 69% of day- and night-time samples were nitrogen-containing, whereas 26% and 24% contained sulfur, respectively. Within these broader molecular categories, we observed a wide variety of molecular features that reveal a diversity of functional groups and moieties. In this presentation, we present the results of our speciation, temporal variability, connections to air parcel back trajectories and other bulk properties, and potential formation pathways.

  8. The value of enduring environmental surrogates as predictors of estuarine benthic macroinvertebrate assemblages

    Science.gov (United States)

    Wildsmith, Michelle D.; Valesini, Fiona J.; Robinson, Samuel F.

    2017-10-01

    This study tested the extent to which spatial differences in the benthic macroinvertebrate assemblages of a temperate microtidal estuary were 'explained' by the enduring (biophysical) vs non-enduring (water and sediment quality) environmental attributes of a diverse range of habitats, and thus the potential of those environmental surrogates to support faunal prediction. Species composition differed significantly among habitats in each season, with the greatest differences occurring in winter and spring and the least in summer. The pattern of habitat differences, as defined by their enduring environmental characteristics, was significantly and well matched with that in the fauna in each season. In contrast, significant matches between the non-enduring environmental and faunal data were only detected in winter and/or spring, and to a lesser extent. Field validation of the faunal prediction capacity of the biophysical surrogate framework at various 'test' sites throughout the estuary showed good agreement between the actual vs predicted key species. These findings demonstrate that enduring environmental criteria, which can be readily measured from mapped data, provide a better and more cost-effective surrogate for explaining spatial differences in the invertebrate fauna of this system than non-enduring criteria, and are thus a promising basis for faunal prediction. The approaches developed in this study are also readily adapted to any estuary worldwide.

  9. Surrogate motherhood in illness that does not cause infertility

    African Journals Online (AJOL)

    Surrogate motherhood in South Africa (SA) is regulated by the. Children's Act,[1] the National Health Act[2] and its regulations,[3] and court cases.[4-6] The Children's Act formulates the legal requirement for a commissioning parent or parents to legally access surrogacy:[1]. 'A court may not confirm a surrogate motherhood ...

  10. Term clouds as surrogates for user generated speech

    NARCIS (Netherlands)

    Tsagkias, M.; Larson, M.; de Rijke, M.; Myaeng, S.-H.; Oard, D.W.; Sebastiani, F.; Chua, T.-S.; Leong, M.-K.

    2008-01-01

    User generated spoken audio remains a challenge for Automatic Speech Recognition (ASR) technology and content-based audio surrogates derived from ASR-transcripts must be error robust. An investigation of the use of term clouds as surrogates for podcasts demonstrates that ASR term clouds closely

  11. Nonspinning numerical relativity waveform surrogates: assessing the model

    Science.gov (United States)

    Field, Scott; Blackman, Jonathan; Galley, Chad; Scheel, Mark; Szilagyi, Bela; Tiglio, Manuel

    2015-04-01

    Recently, multi-modal gravitational waveform surrogate models have been built directly from data numerically generated by the Spectral Einstein Code (SpEC). I will describe ways in which the surrogate model error can be quantified. This task, in turn, requires (i) characterizing differences between waveforms computed by SpEC with those predicted by the surrogate model and (ii) estimating errors associated with the SpEC waveforms from which the surrogate is built. Both pieces can have numerous sources of numerical and systematic errors. We make an attempt to study the most dominant error sources and, ultimately, the surrogate model's fidelity. These investigations yield information about the surrogate model's uncertainty as a function of time (or frequency) and parameter, and could be useful in parameter estimation studies which seek to incorporate model error. Finally, I will conclude by comparing the numerical relativity surrogate model to other inspiral-merger-ringdown models. A companion talk will cover the building of multi-modal surrogate models.

  12. Human surrogate neck response to +Gz vertical impact

    NARCIS (Netherlands)

    Rooij, L. van; Uittenbogaard, J.

    2011-01-01

    For the evaluation of impact scenarios with a substantial vertical component, the performance of current human surrogates - the RID 3D hardware dummy and two numerical human models - was evaluated. Volunteer tests with 10G and 6G pulses were compared to reconstructed tests with human surrogates.

  13. On Design Mining: Coevolution and Surrogate Models.

    Science.gov (United States)

    Preen, Richard J; Bull, Larry

    2017-01-01

    Design mining is the use of computational intelligence techniques to iteratively search and model the attribute space of physical objects evaluated directly through rapid prototyping to meet given objectives. It enables the exploitation of novel materials and processes without formal models or complex simulation. In this article, we focus upon the coevolutionary nature of the design process when it is decomposed into concurrent sub-design-threads due to the overall complexity of the task. Using an abstract, tunable model of coevolution, we consider strategies to sample subthread designs for whole-system testing and how best to construct and use surrogate models within the coevolutionary scenario. Drawing on our findings, we then describe the effective design of an array of six heterogeneous vertical-axis wind turbines.

  14. [Surrogate maternity--literature review and practice].

    Science.gov (United States)

    Pilka, L; Rumpík, D; Pilka, R; Koudelka, M; Prudil, L

    2009-04-01

    This review summarizes opinions on surrogacy including internatinal and governmental organizations attitudes, as well as some religious concerns. Literature review. Reprofit International, Brno, Reproductive medicine and gynecology centre, Zlin, Department of obstetrics and gynecology, Palacky University, Olomouc. The developments in the field of assissted reproduction during the last twenty years have attracted unexpected public interest in some of its ethical and moral aspects. It is very difficult to find a uniform attitude to ethical concerns of assisted conception in plural society. Surrogate mother is defined as a woman who bears and relinquishes a child for another person. The european congress on human reproduction in Barcelona 2008 adopted following résumé on surrogacy: Public opinion has shifted to a position where surrogacy is recognized as an appropriate response to infertility in some circumstances and it is to be expected that this approach will be further strenghtened with stress on positive aspects of familiar life.

  15. Naturally occurring flavonoids against human norovirus surrogates.

    Science.gov (United States)

    Su, Xiaowei; D'Souza, Doris H

    2013-06-01

    Naturally occurring plant-derived flavonoids are reported to have antibacterial, antiviral, and pharmacological activities. The objectives of this study were to determine the antiviral effects of four flavonoids (myricetin, L-epicatechin, tangeretin, and naringenin) on the infectivity of food borne norovirus surrogates after 2 h at 37 °C. The lab-culturable surrogates, feline calicivirus (FCV-F9) at titers of ~7 log₁₀ PFU/ml (high titer) or ~5 log₁₀ PFU/ml (low titer) and murine norovirus (MNV-1) at ~5 log₁₀ PFU/ml, were mixed with equal volumes of myricetin, L-epicatechin, tangeretin, or naringenin at concentrations of 0.5 or 1 mM, and incubated for 2 h at 37 °C. Treatments of viruses were neutralized in cell culture medium containing 10 % heat-inactivated fetal bovine serum, serially diluted, and plaque assayed. Each treatment was replicated thrice and assayed in duplicate. FCV-F9 (low titer) was not found to be reduced by tangeretin or naringenin, but was reduced to undetectable levels by myricetin at both concentrations. Low titer FCV-F9 was also decreased by 1.40 log₁₀ PFU/ml with L-epicatechin at 0.5 mM. FCV-F9 at high titers was decreased by 3.17 and 0.72 log₁₀ PFU/ml with myricetin and L-epicatechin at 0.5 mM, and 1.73 log10 PFU/ml with myricetin at 0.25 mM, respectively. However, MNV-1 showed no significant inactivation by the four tested treatments. The antiviral effects of the tested flavonoids are dependent on the virus type, titer, and dose. Further research will focus on understanding the antiviral mechanism of myricetin and L-epicatechin.

  16. Surrogate Motherhood and Abortion for Fetal Abnormality.

    Science.gov (United States)

    Walker, Ruth; van Zyl, Liezl

    2015-10-01

    A diagnosis of fetal abnormality presents parents with a difficult - even tragic - moral dilemma. Where this diagnosis is made in the context of surrogate motherhood there is an added difficulty, namely that it is not obvious who should be involved in making decisions about abortion, for the person who would normally have the right to decide - the pregnant woman - does not intend to raise the child. This raises the question: To what extent, if at all, should the intended parents be involved in decision-making? In commercial surrogacy it is thought that as part of the contractual agreement the intended parents acquire the right to make this decision. By contrast, in altruistic surrogacy the pregnant woman retains the right to make these decisions, but the intended parents are free to decide not to adopt the child. We argue that both these strategies are morally unsound, and that the problems encountered serve to highlight more fundamental defects within the commercial and altruistic models, as well as in the legal and institutional frameworks that support them. We argue in favour of the professional model, which acknowledges the rights and responsibilities of both parties and provides a legal and institutional framework that supports good decision-making. In particular, the professional model acknowledges the surrogate's right to decide whether to undergo an abortion, and the intended parents' obligation to accept legal custody of the child. While not solving all the problems that arise in surrogacy, the model provides a framework that supports good decision-making. © 2015 John Wiley & Sons Ltd.

  17. Multiple Surrogate Modeling for Wire-Wrapped Fuel Assembly Optimization

    International Nuclear Information System (INIS)

    Raza, Wasim; Kim, Kwang-Yong

    2007-01-01

    In this work, shape optimization of seven pin wire wrapped fuel assembly has been carried out in conjunction with RANS analysis in order to evaluate the performances of surrogate models. Previously, Ahmad and Kim performed the flow and heat transfer analysis based on the three-dimensional RANS analysis. But numerical optimization has not been applied to the design of wire-wrapped fuel assembly, yet. Surrogate models are being widely used in multidisciplinary optimization. Queipo et al. reviewed various surrogates based models used in aerospace applications. Goel et al. developed weighted average surrogate model based on response surface approximation (RSA), radial basis neural network (RBNN) and Krigging (KRG) models. In addition to the three basic models, RSA, RBNN and KRG, the multiple surrogate model, PBA also has been employed. Two geometric design variables and a multi-objective function with a weighting factor have been considered for this problem

  18. Comparison of the chemical composition of three species of smartweed (genus Persicaria) with a focus on drimane sesquiterpenoids.

    Science.gov (United States)

    Prota, N; Mumm, R; Bouwmeester, H J; Jongsma, M A

    2014-12-01

    The genus Persicaria is known to include species accumulating drimane sesquiterpenoids, but a comparative analysis highlighting the compositional differences has not been done. In this study, the secondary metabolites of both flowers and leaves of Persicariahydropiper, Persicariamaculosa and Persicariaminor, three species which occur in the same habitat, were compared. Using gas chromatography-mass spectrometry (GC-MS) analysis of extracts, overall 21/29 identified compounds in extracts were sesquiterpenoids and 5/29 were drimanes. Polygodial was detected in all species, though not in every sample of P. maculosa. On average, P. hydropiper flowers contained about 6.2 mg g FW(-1) of polygodial, but P. minor flowers had 200-fold, and P. maculosa 100,000 fold lower concentrations. Comparatively, also other sesquiterpenes were much lower in those species, suggesting the fitness benefit to depend on either investing a lot or not at all in terpenoid-based secondary defences. For P. hydropiper, effects of flower and leaf development and headspace volatiles were analysed as well. The flower stage immediately after fertilisation was the one with the highest content of drimane sesquiterpenoids and leaves contained about 10-fold less of these compounds compared to flowers. The headspace of P. hydropiper contained 8 compounds: one monoterpene, one alkyl aldehyde and six sesquiterpenes, but none were drimanes. The potential ecological significance of the presence or absence of drimane sesquiterpenoids and other metabolites for these plant species are discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Chemical Composition and in-Vitro Evaluation of the Antimicrobial and Antioxidant Activities of Essential Oils Extracted from Seven Eucalyptus Species

    Directory of Open Access Journals (Sweden)

    Abdul Ghaffar

    2015-11-01

    Full Text Available Eucalyptus is well reputed for its use as medicinal plant around the globe. The present study was planned to evaluate chemical composition, antimicrobial and antioxidant activity of the essential oils (EOs extracted from seven Eucalyptus species frequently found in South East Asia (Pakistan. EOs from Eucalyptus citriodora, Eucalyptus melanophloia, Eucalyptus crebra, Eucalyptus tereticornis, Eucalyptus globulus, Eucalyptus camaldulensis and Eucalyptus microtheca were extracted from leaves through hydrodistillation. The chemical composition of the EOs was determined through GC-MS-FID analysis. The study revealed presence of 31 compounds in E. citriodora and E. melanophloia, 27 compounds in E. crebra, 24 compounds in E. tereticornis, 10 compounds in E. globulus, 13 compounds in E. camaldulensis and 12 compounds in E. microtheca. 1,8-Cineole (56.5%, α-pinene (31.4%, citrinyl acetate (13.3%, eugenol (11.8% and terpenene-4-ol (10.2% were the highest principal components in these EOs. E. citriodora exhibited the highest antimicrobial activity against the five microbial species tested (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Aspergillus niger and Rhizopus solani. Gram positive bacteria were found more sensitive than Gram negative bacteria to all EOs. The diphenyl-1-picrylhydazyl (DPPH radical scavenging activity and percentage inhibition of linoleic acid oxidation were highest in E. citriodora (82.1% and 83.8%, respectively followed by E. camaldulensis (81.9% and 83.3%, respectively. The great variation in chemical composition of EOs from Eucalyptus, highlight its potential for medicinal and nutraceutical applications.

  20. Chemical Composition and in-Vitro Evaluation of the Antimicrobial and Antioxidant Activities of Essential Oils Extracted from Seven Eucalyptus Species.

    Science.gov (United States)

    Ghaffar, Abdul; Yameen, Muhammad; Kiran, Shumaila; Kamal, Shagufta; Jalal, Fatima; Munir, Bushra; Saleem, Sadaf; Rafiq, Naila; Ahmad, Aftab; Saba, Iram; Jabbar, Abdul

    2015-11-18

    Eucalyptus is well reputed for its use as medicinal plant around the globe. The present study was planned to evaluate chemical composition, antimicrobial and antioxidant activity of the essential oils (EOs) extracted from seven Eucalyptus species frequently found in South East Asia (Pakistan). EOs from Eucalyptus citriodora, Eucalyptus melanophloia, Eucalyptus crebra, Eucalyptus tereticornis, Eucalyptus globulus, Eucalyptus camaldulensis and Eucalyptus microtheca were extracted from leaves through hydrodistillation. The chemical composition of the EOs was determined through GC-MS-FID analysis. The study revealed presence of 31 compounds in E. citriodora and E. melanophloia, 27 compounds in E. crebra, 24 compounds in E. tereticornis, 10 compounds in E. globulus, 13 compounds in E. camaldulensis and 12 compounds in E. microtheca. 1,8-Cineole (56.5%), α-pinene (31.4%), citrinyl acetate (13.3%), eugenol (11.8%) and terpenene-4-ol (10.2%) were the highest principal components in these EOs. E. citriodora exhibited the highest antimicrobial activity against the five microbial species tested (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Aspergillus niger and Rhizopus solani). Gram positive bacteria were found more sensitive than Gram negative bacteria to all EOs. The diphenyl-1-picrylhydazyl (DPPH) radical scavenging activity and percentage inhibition of linoleic acid oxidation were highest in E. citriodora (82.1% and 83.8%, respectively) followed by E. camaldulensis (81.9% and 83.3%, respectively). The great variation in chemical composition of EOs from Eucalyptus, highlight its potential for medicinal and nutraceutical applications.

  1. Comments on Surrogates measures and consistent surrogates (by Tyler VanderWeele)

    Science.gov (United States)

    2013-03-01

    as a criterion for “good” surrogate, why can’t we create a new, formal definition of “ surrogacy ” that (1) will automatically avoid the paradox and (2...requirement of avoiding the paradox could not, in itself, constitute a satisfactory definition of surrogacy . As with other paradoxes of causal...situation in practice. A treatment that has such a negative direct effect on outcome would rarely be a candidate for surrogacy analysis. In practice

  2. Inactivation kinetics and efficiencies of UV-LEDs against Pseudomonas aeruginosa, Legionella pneumophila, and surrogate microorganisms.

    Science.gov (United States)

    Rattanakul, Surapong; Oguma, Kumiko

    2018-03-01

    To demonstrate the effectiveness of UV light-emitting diodes (UV-LEDs) to disinfect water, UV-LEDs at peak emission wavelengths of 265, 280, and 300 nm were adopted to inactivate pathogenic species, including Pseudomonas aeruginosa and Legionella pneumophila, and surrogate species, including Escherichia coli, Bacillus subtilis spores, and bacteriophage Qβ in water, compared to conventional low-pressure UV lamp emitting at 254 nm. The inactivation profiles of each species showed either a linear or sigmoidal survival curve, which both fit well with the Geeraerd's model. Based on the inactivation rate constant, the 265-nm UV-LED showed most effective fluence, except for with E. coli which showed similar inactivation rates at 265 and 254 nm. Electrical energy consumption required for 3-log 10 inactivation (E E,3 ) was lowest for the 280-nm UV-LED for all microbial species tested. Taken together, the findings of this study determined the inactivation profiles and kinetics of both pathogenic bacteria and surrogate species under UV-LED exposure at different wavelengths. We also demonstrated that not only inactivation rate constants, but also energy efficiency should be considered when selecting an emission wavelength for UV-LEDs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Induction of molecular endpoints by reactive oxygen species in human lung cells predicted by physical chemical properties of engineered nanoparticles

    Science.gov (United States)

    A series of six titanium dioxide and two cerium oxide engineered nanomaterials were assessed for their ability to induce cytotoxicity, reactive oxygen species (ROS), and various types of DNA and protein damage in human respiratory BEAS-2B cells exposed in vitro for 72 hours at se...

  4. Cumulative Index to Chemicals and to Common and Scientific Names of Species Listed in Contaminant Hazard Reviews 1 Through 34.

    Science.gov (United States)

    1999-03-01

    Wildlife Research Center- synthesizes ecotoxicological data for selected environmental contaminants, with emphasis on hazards to native species of flora...series-—sponsored by the U.S. Geological Survey Patuxent Wildlife Research Center—synthesizes ecotoxicological data for selected environmental...7 37. Macronectes giganteus: 32 16; 33 26; 34 27. Macrophytes , aquatic, Cabomba spp., Chara sp., Elodea, Lemna, Myriophyllum, Polygonum sp

  5. Phylogenetic and chemical studies in the potential psychotropic species complex of Psilocybe atrobrunnea with taxonomic and nomenclatural notes

    NARCIS (Netherlands)

    Borovička, J.; Oborník, M.; Stříbrný, J.; Noordeloos, M.E.; Parra Sánchez, L.A.; Gryndler, M.

    2015-01-01

    Five Psilocybe species with unresolved systematic position (P. atrobrunnea, P. laetissima, P. medullosa, P. pelliculosa, and P. silvatica) were investigated using four molecular markers (EF1-α, ITS, LSU, and IGS). Phylogenetic analysis revealed that with the exception of P. laetissima, which is now

  6. Chemical composition and fumigant toxicity of the essential oils from 16 species of Eucalyptus against Haematobia irritans (Diptera: Muscidae) adults

    OpenAIRE

    Juan, Laura W.; Lucía Mulas, Alejandro; Zerba, Eduardo N.; Harrand, Leonel; Marco, Martín; Masuh, Hector M.

    2011-01-01

    Oils extracted from various species of Eucalyptus (Eucalyptus badjensis Beuzev & Welch, Eucalyptus badjensis x Eucalyptus nitens, Eucalyptus benthamii variety dorrigoensis Maiden & Cambage, Eucalyptus botryoides Smith, Eucalyptus dalrympleana Maiden, Eucalyptus fastigata Deane & Maiden, Eucalyptus nobilis L.A.S. Johnson & K. D. Hill, Eucalyptus polybractea R. Baker, Eucalyptus radiata ssp. radiata Sieber ex Spreng, Eucalyptus resinifera Smith, Eucalyptus robertsonii Blakely, Eucalyptus rubida...

  7. Effect of seed treatments on the chemical composition and properties of two amaranth species: starch and protein

    NARCIS (Netherlands)

    Gamel, T.H.; Linssen, J.P.H.; Mesallem, A.S.; Damir, A.A.; Shekib, L.A.

    2005-01-01

    The seeds of two Amaranth species were studied. The starch contents were 543 and 623 g kg-1 while crude protein contents were 154 and 169 g kg-1 for Amaranthus caudatus and Amaranthus cruentus seeds, respectively. The effect of several treatments, including cooking, popping and germination and flour

  8. Neutron-induced cross-sections via the surrogate method

    International Nuclear Information System (INIS)

    Boutoux, G.

    2011-11-01

    The surrogate reaction method is an indirect way of determining neutron-induced cross sections through transfer or inelastic scattering reactions. This method presents the advantage that in some cases the target material is stable or less radioactive than the material required for a neutron-induced measurement. The method is based on the hypothesis that the excited nucleus is a compound nucleus whose decay depends essentially on its excitation energy and on the spin and parity state of the populated compound state. Nevertheless, the spin and parity population differences between the compound-nuclei produced in the neutron and transfer-induced reactions may be different. This work reviews the surrogate method and its validity. Neutron-induced fission cross sections obtained with the surrogate method are in general good agreement. However, it is not yet clear to what extent the surrogate method can be applied to infer radiative capture cross sections. We performed an experiment to determine the gamma decay probabilities for 176 Lu and 173 Yb by using the surrogate reactions 174 Yb( 3 He,pγ) 176 Lu * and 174 Yb( 3 He,αγ) 173 Yb * , respectively, and compare them with the well-known corresponding probabilities obtained in the 175 Lu(n,γ) and 172 Yb(n,γ) reactions. This experiment provides answers to understand why, in the case of gamma-decay, the surrogate method gives significant deviations compared to the corresponding neutron-induced reaction. In this work, we have also assessed whether the surrogate method can be applied to extract capture probabilities in the actinide region. Previous experiments on fission have also been reinterpreted. Thus, this work provides new insights into the surrogate method. This work is organised in the following way: in chapter 1, the theoretical aspects related to the surrogate method will be introduced. The validity of the surrogate method will be investigated by means of statistical model calculations. In chapter 2, a review on

  9. The composition of surrogate and illegal alcohol products in Estonia.

    Science.gov (United States)

    Lang, Katrin; Väli, Marika; Szucs, Sándor; Adány, Róza; McKee, Martin

    2006-01-01

    To identify the composition of illegal and surrogate alcohol products consumed in Estonia. The initial source of information was a series of visits made in August 2005 to a soup kitchen in central Tartu, Estonia. Individuals were asked for brief details of their personal circumstances, what they normally drank, and in addition they were asked to bring samples of the substances they usually consumed. In other cases, the substances identified were purchased by the investigators or from informal contacts in north-eastern part of Estonia, an area that is well known for illegal alcohol consumption. Samples were tested for chemical contents. We identified a range of alcohol-containing substances that are consumed, although, not intended for consumption. These comprised medicinal products, aftershaves, illegally produced spirits, and fire-lighting fuel. The medicinal compounds contained, on average, 67% ethanol by volume; the aftershaves contained slightly less. Both were typically pure, with a few containing detectable quantities of isoamyl alcohol. The illegally produced alcohol contained, on average, 43% ethanol by volume, ranging from 32 to 53%. However, many also contained detectable quantities of long chain alcohols. These substances are half the price or less of commercial vodka, with fire lighting fuels especially inexpensive. There is in Estonia a range of alcohol-containing substances easily available at low cost. Some contain substantially higher concentrations of ethanol than commercial spirits and others also contain toxic long chain alcohols.

  10. Comparison of chemical profiles between the root and aerial parts from three Bupleurum species based on a UHPLC-QTOF-MS metabolomics approach.

    Science.gov (United States)

    Zhu, Lin; Liang, Zhi-Tao; Yi, Tao; Ma, Yue; Zhao, Zhong-Zhen; Guo, Bao-Lin; Zhang, Jian-Ye; Chen, Hu-Biao

    2017-06-12

    Bupleuri Radix (Chaihu) represents one of the most successful and widely used herbal medicines in Asia for the treatment of many diseases such as inflammatory disorders and infectious diseases over the past 2000 years. In the Chinese Pharmacopoeia, Chaihu is recorded as the dried roots of Bupleurum chinense DC. and B. scorzonerifolium Willd. (Umbelliferae). However, the widespread demand for the herb has tended to far outstrip the supply. Whether the aerial parts, which account for 70 ~ 85% of the dry weights of Bupleurum species, could be used as an alternative for the root has become an important scientific issue for the sustainable utilization of Bupleurum species. On the other hand, in some areas including the southeast of China as well as in Spain, the aerial parts of Bupleurum species have already been used in the folk medications. Therefore, to clarify whether the root and aerial parts of Bupleurum species are "equivalent" in the types and quantities of chemical constituents which subsequently influence their biological activities and therapeutic effects is of great importance for both the rational and sustainable use of this herb. In the present study, the chemical profiles between the root and aerial parts of Bupleurum species from different species and collected from various locations were analyzed and compared by the ultra-high performance liquid chromatography quadrupole/time of flight-mass spectrometry (UHPLC-QTOF-MS). A total of 56 peaks were identified in the root and/or aerial parts from different batches of Bupleurum species, by comparison of references standards or with those reported in the literature. Principal Component Analysis (PCA) was conducted for displaying the differentiating clustering between these two parts. The results disclosed the distinct variations between them, which indicated that the aerial parts could not be used as an alternative of root from a chemodiversity perspective. The differentiating markers resulted from the PCA

  11. Modeling response of species to microcontaminants: comparative ecotoxicology by (sub)lethal body burdens as a function of species size and partition ratio of chemicals.

    Science.gov (United States)

    Hendriks, A J

    1995-11-01

    -term versus long-term, lethal versus sublethal, and median versus no response concentration ratios each contributed factors of about 2-3 to this overall ratio. The model for internal concentrations indicated that the ratio between the short-term and the long-term LC50 will be high for large species and high octanol-water partition ratios.

  12. Electrochemical corrosion studies on a selected carbon steel for application in nuclear waste disposal containers: Influence of chemical species in brines on corrosion

    International Nuclear Information System (INIS)

    Farvaque-Bera, A.M.; Smailos, E.

    1994-04-01

    In previous corrosion studies, carbon steels were identified as promising materials for the manufacture of long-lived high-level waste containers that could act as an engineered barrier in a rock-salt repository. In this paper, the influence of chemical species, potentially present in salt brines, on the electrochemical corrosion behavior of the preselected fine-grained steel TStE 355 was studied. The steel was examined at 90 C in a disposal relevant NaCl-rich brine containing various species (Br - , I - , Cu 2+ , Mn 2+ , S 2- , B(OH )4 - and Fe 3+ ) at concentrations between 10 -5 M/I and 10 -1 M/I. (orig.) [de

  13. Essential Oils of Myrtaceae Species Growing Wild in Tunisia: Chemical Variability and Antifungal Activity Against Biscogniauxia mediterranea, the Causative Agent of Charcoal Canker.

    Science.gov (United States)

    Yangui, Islem; Zouaoui Boutiti, Meriem; Boussaid, Mohamed; Messaoud, Chokri

    2017-07-01

    The chemical composition of five Eucalyptus species and five Myrtus communis L. populations was investigated using GC/MS and GC-FID. For Eucalyptus essential oils, 32 compounds, representing 88.56 - 96.83% of the total oil according to species, were identified. The main compounds were 1,8-cineole, α-pinene, p-cymene, γ-gurjunene, α-aromadendrene, and β-phellandrene. For Myrtle essential oils, 26 compounds, representing 93.13 - 98.91% of the total oil were identified. α-Pinene, 1,8-cineole, linalool, and myrtenyl acetate were found to be the major compounds. Principal component analysis (PCA) showed chemical differentiation between Eucalyptus species and between Myrtle populations. Biscogniauxia mediterranea, the causative agent of charcoal canker, was identified according to its morphological and molecular characteristics. Essential oils of the investigated Eucalyptus species and Myrtle populations were tested for their antifungal capacity against this fungus. The antifungal activity varied according to the essential oil composition. Biscogniauxia mediterranea exhibited powerful resistance to some essential oils including them of Eucalyptus lehmannii and Eucalyptus sideroxylon but it was very sensitive to Eucalyptus camaldulensis oil (IC 50  = 3.83 mg/ml) and M. communis oil from Zaghouan (IC 50  = 1 mg/ml). This sensitivity was found to be correlated to some essential oil compounds such as p-cymene, carvacrol, cuminaldehyde, and linalool. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  14. CHEMICAL COMPOSITION, IN VITRO RUMEN FERMENTATION, AND DIGESTIBILITY OF SELECTED BROWSE SPECIES BY BUFFALOES (Bubalus bubalis L. AT A SEMI-DECIDUOUS FOREST IN VENEZUELA

    Directory of Open Access Journals (Sweden)

    Álvaro José Ojeda

    2013-01-01

    Full Text Available To determine the chemical composition and nutritive value of selected browse species by buffaloes (Bubalus bubalis L. in a silvopastoral system at a semi-deciduous tropical forest (SDTF, epidermal fragments in fecal samples from 14 males of Murrah breed were evaluated. The animals grazed for 91 days in 85 ha located in Portuguesa State, Venezuela, of which 35 ha corresponded to natural grass pastures (969.3 ± 28.6 kg DM ha-1, and the rest to SDTF with 463 plant ha-1. Eleven botanical families and 22 species were identified, 40.9% belonged to the Fabaceae family. The specie Guazuma ulmifolia (Sterculiaceae had the highest relative dominancy (60.4% and an Importance Value Index of 162.6. 60.4% of epidermal fragments corresponded to herbaceous Poaceae, and the rest was distributed among five different species, with the highest occurrence (94.6% for Samanea saman and Sida acuta. There were differences (P

  15. Emotional experiences in surrogate mothers: A qualitative study.

    Science.gov (United States)

    Ahmari Tehran, Hoda; Tashi, Shohreh; Mehran, Nahid; Eskandari, Narges; Dadkhah Tehrani, Tahmineh

    2014-07-01

    Surrogacy is one of the new techniques of assisted reproduction technology in which a woman carries and bears a child for another woman. In Iran, many Shia clerics and jurists considered it permissible so there is no religious prohibition for it. In addition to the risk of physical complications for complete surrogate mothers, the possibility of psychological complications resulted from emotional attachment to a living creature in the surrogate mother as another injury requires counseling and assessment prior to acceptance by infertile couples and complete surrogate mothers. The purpose of this study was to assess the emotional experiences of surrogate mothers. This was a qualitative, phenomenological study. We selected eight complete surrogate mothers in Isfahan. We used convenient sampling method and in-depth interview to collect the information. The data analysis was fulfilled via Colaizzi's seven-stage method. Reliability and validity study of the roots in the four-axis was done. The findings of these interviews were classified into two main themes and four sub themes: acquired experiences in pregnancy (feelings toward pregnancy, relationship with family, relatives and commissioning couple) and consequences of surrogacy (complications of pregnancy, religious and financial problems of surrogacy). Surrogacy pregnancy should be considered as high-risk emotional experience because many of surrogate mothers may face negative experiences. Therefore, it is recommended that surrogates should receive professional counseling prior to, during and following pregnancy.

  16. [The surrogate: Partner in the shared decision-making].

    Science.gov (United States)

    Sarradon-Eck, Aline; Capodano, Géraldine; Bureau, Eve; Julian-Reynier, Claire

    2016-01-01

    The legislative process of the surrogate appears to be unclear to health professionals and to patients and next of kin. To better adapt this process to the clinical practice our objective was here to document how the persons designated as surrogate perceived their role and how they described the difficulties encountered in oncology. Qualitative survey with an ethnographic approach carried out in 2014-2015, fieldwork, face-to-face interviews (n=26 including 20 surrogates and 6 patients) in a mobile palliative care unit located at a Regional Comprehensive Cancer Centre. Close relationship, psychological and cognitive competences were the main attribute to designate a surrogate. Perceived roles included the fact to be involved in decisions, to protect the patient, to be present, and to be a messenger. This process gives the next of kin the feeling to be part of the patient management. In the context of divorced families, it sometimes allows to rehabilitate and to reinforce the affective links. Our data highlight the confusion between the designation of the 'person to call' and 'the surrogate'. Our results highlight the 'surrogate' protective role of the patient, and the positive sides of the process, in particular in the context of divorced/rebuilt families. We recommend splitting the process to designate the 'person to call' and the 'surrogate', as administrative and medical duties, respectively. Copyright © 2016 Société Française du Cancer. Published by Elsevier Masson SAS. All rights reserved.

  17. Modelling of Combustion and Pollutant Formation in a Large, Two-Stroke Marine Diesel Engine using Integrated CFD-Skeletal Chemical Mechanism

    DEFF Research Database (Denmark)

    Pang, Kar Mun; Karvounis, Nikolas; Schramm, Jesper

    In this reported work, simulation studies of in-cylinder diesel combustion and pollutant formation processesin a two-stroke, low-speed uniflow-scavenged marine diesel engine are presented. Numerical computation is performed by integrating chemical kinetics into CFD computations. In order...... to minimize the computational runtime, an in-house skeletal n-heptane chemical mechanism is coupled with the CFD model. This surrogate fuel model comprises 89 reactions with 32 species essential to diesel ignition/combustion processes as well as the formation of soot precursors and nitrogen monoxide (NO......). Prior to the marine engine simulation,coupling of the newly developed surrogate fuel model and a revised multi-step soot model [1] is validated on the basis of optical diagnostics measurement obtained at varying ambient pressure levels [2]. It is demonstrated that the variation of ignition delay times...

  18. Surrogate model approach for improving the performance of reactive transport simulations

    Science.gov (United States)

    Jatnieks, Janis; De Lucia, Marco; Sips, Mike; Dransch, Doris

    2016-04-01

    (MARS) method provides the best trade-off between speed and accuracy. This proof-of-concept forms an essential step towards building an interactive visual analytics system to enable user-driven systematic creation of geochemical surrogate models. Such a system shall enable reactive transport simulations with unprecedented spatial and temporal detail to become possible. References: Kolditz, O., Görke, U.J., Shao, H. and Wang, W., 2012. Thermo-hydro-mechanical-chemical processes in porous media: benchmarks and examples (Vol. 86). Springer Science & Business Media.

  19. Chemical analysis and antioxidant activity of the essential oils of three Piperaceae species growing in the central region of Cuba.

    Science.gov (United States)

    Rodríguez, Elisa Jorge; Saucedo-Hernández, Yanelis; Vander Heyden, Yvan; Simó-Alfonso, Ernesto F; Ramis-Ramos, Guillermo; Lerma-García, María Jesús; Monteagudo, Urbano; Bravo, Luis; Medinilla, Mildred; de Armas, Yuriam; Herrero-Martínez, José Manuel

    2013-09-01

    The present study describes the phytochemical profile and antioxidant activity of the essential oils of three Piperaceae species collected in the central region of Cuba. The essential oils of Piper aduncum, P. auritum and P. umbellatum leaves, obtained by hydrodistillation, were analyzed by gas chromatography-mass spectrometry. The main components of P. aduncum oil were piperitone (34%), camphor (17.1%), camphene (10.9%), 1,8-cineol (8.7%) and viridiflorol (7.4%), whereas that of P. auritum and P. umbellatum was safrole (71.8 and 26.4%, respectively). The antioxidant properties of the essential oils were also evaluated using several assays for radical scavenging ability (DPPH test and reducing power) and inhibition of lipid oxidation (ferric thiocyanate method and evaluation against Cucurbita seed oil by peroxide, thiobarbituric acid and p-anisidine methods). P. auritum showed the strongest antioxidant activity among the Piper species investigated, but lower than those of butylated hydroxyanisol and propyl gallate.

  20. Nitrogen complex species and its chemical nature in TiO2 for visible-light sensitized photocatalysis

    International Nuclear Information System (INIS)

    Asahi, Ryoji; Morikawa, Takeshi

    2007-01-01

    A photocatalyst with high reactivity under visible-light has been desired to utilize solar irradiation or interior lighting efficiently. Nitrogen-doped TiO 2 revealed significant improvement in optical absorption and photocatalytic activity over TiO 2 under visible light. We have performed the first-principles calculations to study the detailed N complex species introduced in TiO 2 . The results include stable geometries, densities of states, formation energies, and core levels. The present systematic studies account for the long-term controversial issue on N-doped TiO 2 , in particular, regarding the detailed assignment of N 1s binding energies observed in the XPS measurement. The detailed analyses of the formation energies show that introducing the N species more in a controlled way via process conditions is crucial to achieve the optimized photocatalytic performance

  1. Comparison of the Chemical Profiles and Antioxidant and Antidiabetic Activities of Extracts from Two Ganoderma Species (Agaricomycetes).

    Science.gov (United States)

    Tang, Xiaoqing; Cai, Weixi; Xu, Baojun

    2016-01-01

    The objective of this study was to compare the mycochemical profiles, antioxidant activities, and antidiabetic effects of 2 species of genus Ganoderma, the red lingzhi (G. lucidum) and purple lingzhi (G. sinense) mushrooms. In Chinese medicinal practice, hot water and ethanol are used as solvents to extract samples. In this study, a total of 4 extracts (ethanol and hot water extracts from G. lucidum and G. sinense) were prepared for further assays. Hot water extracts presented much higher values for total phenolic content and ferric-reducing antioxidant power than the ethanol extracts. Ethanol (70%) extract of G. lucidum had the strongest α-glycosidase inhibitory capacity, but the lingzhi polysaccharides showed no inhibitory effect. It also had the largest amount of total ganoderic acids. The results indicated that ethanol extracts from both G. lucidum and G. sinense showed better antidiabetic effects than the hot water extracts. Ganoderic acids, rather than polysaccharides, may contribute the antidiabetic effects of both the Ganoderma species.

  2. Chemical analysis of reactive species and antimicrobial activity of/nwater treated by nanosecond pulsed DBD air plasma

    Czech Academy of Sciences Publication Activity Database

    Laurita, R.; Barbieri, D.; Gherardi, M.; Colombo, V.; Lukeš, Petr

    2015-01-01

    Roč. 3, č. 2 (2015), s. 53-61 ISSN 2212-8166 R&D Projects: GA MŠk(CZ) LD14080 Grant - others:European Cooperation in Science and Technology(XE) COST TD1208 Institutional support: RVO:61389021 Keywords : Dielectric barrier discharge * Plasma activated water * Reactive species * Peroxynitrite * Phenol degradation * Candida albicans * Staphylococcus aureus * Antimicrobial activity * Nosocomial infections Subject RIV: BL - Plasma and Gas Discharge Physics http://www.sciencedirect.com/science/article/pii/S2212816615300081

  3. Floral nectary, nectar production dynamics and chemical composition in five nocturnal Oenothera species (Onagraceae) in relation to floral visitors.

    Science.gov (United States)

    Antoń, Sebastian; Komoń-Janczara, Elwira; Denisow, Bożena

    2017-12-01

    Main conclusion The floral nectars were sucrose-dominant; however, nectar protein and amino acid contents differed, indicating that composition of nitrogenous compounds may vary considerably even between closely related plant species, irrespectively of nectary structure. Numerous zoophilous plants attract their pollinators by offering floral nectar; an aqueous solution produced by specialized secretory tissues, known as floral nectaries. Although many papers on nectaries and nectar already exist, there has been a little research into the structure of nectaries and/or nectar production and composition in species belonging to the same genus. To redress this imbalance, we sought, in the present paper, to describe the floral nectary, nectar production, and nectar composition in five nocturnal Oenothera species with respect to their floral visitors. The structure of nectaries was similar for all the species investigated, and comprised the epidermis (with nectarostomata), numerous layers of nectary parenchyma, and subsecretory parenchyma. Anthesis for a single flower was short (ca. 10-12 h), and flowers lasted only one night. The release of floral nectar commenced at the bud stage (approx. 4 h before anthesis) and nectar was available to pollinators until petal closure. Nectar concentration was relatively low (ca. 27%) and the nectar was sucrose-dominant, and composed mainly of sucrose, glucose and fructose. The protein content of the nectar was also relatively low (on average, 0.31 µg ml -1 ). Nevertheless, a great variety of amino acids, including both protein and non-protein types, was detected in the nectar profile of the investigated taxa. We noted both diurnal and nocturnal generalist, opportunistic floral insect visitors.

  4. Adaptive surrogate model based multiobjective optimization for coastal aquifer management

    Science.gov (United States)

    Song, Jian; Yang, Yun; Wu, Jianfeng; Wu, Jichun; Sun, Xiaomin; Lin, Jin

    2018-06-01

    In this study, a novel surrogate model assisted multiobjective memetic algorithm (SMOMA) is developed for optimal pumping strategies of large-scale coastal groundwater problems. The proposed SMOMA integrates an efficient data-driven surrogate model with an improved non-dominated sorted genetic algorithm-II (NSGAII) that employs a local search operator to accelerate its convergence in optimization. The surrogate model based on Kernel Extreme Learning Machine (KELM) is developed and evaluated as an approximate simulator to generate the patterns of regional groundwater flow and salinity levels in coastal aquifers for reducing huge computational burden. The KELM model is adaptively trained during evolutionary search to satisfy desired fidelity level of surrogate so that it inhibits error accumulation of forecasting and results in correctly converging to true Pareto-optimal front. The proposed methodology is then applied to a large-scale coastal aquifer management in Baldwin County, Alabama. Objectives of minimizing the saltwater mass increase and maximizing the total pumping rate in the coastal aquifers are considered. The optimal solutions achieved by the proposed adaptive surrogate model are compared against those solutions obtained from one-shot surrogate model and original simulation model. The adaptive surrogate model does not only improve the prediction accuracy of Pareto-optimal solutions compared with those by the one-shot surrogate model, but also maintains the equivalent quality of Pareto-optimal solutions compared with those by NSGAII coupled with original simulation model, while retaining the advantage of surrogate models in reducing computational burden up to 94% of time-saving. This study shows that the proposed methodology is a computationally efficient and promising tool for multiobjective optimizations of coastal aquifer managements.

  5. Surrogate motherhood as a medical treatment procedure for women's infertility.

    Science.gov (United States)

    Jovic, Olga S

    2011-03-01

    The content of this work is conceived on the research of the consequences of surrogate motherhood as a process of assisted procreation, which represent a way of parenthood in cases when it is not possible to realize parenthood through a natural way. Surrogate motherhood is a process in which a woman (surrogate mother) agrees to carry a pregnancy with the intent to give the child to the couple with whom she has made a contract on surrogate maternity after the birth. This process of conception and birth makes the determination of the child's origin on its mother's side hard to determine, because of the distinction of the genetic and gestation phases of the two women. The concept of surrogate motherhood is to appear in two forms, depending on the existence or the non-existence of the genetic link between the surrogate mother and the child she gives birth to. There are gestation (full) and genetic (partial) surrogates each with different modalities and legal and ethical implications. In Serbia, Infertility Treatment and the Bio-medically Assisted Procreation Act from 2009 explicitly forbids surrogate motherhood, despite the fact that an infertile couple decides to use it, as a rule, after having tried all other treatment procedures, in cases when there is a diagnosis but the conventional treatment applied has not produced the desired results. Given the fact that no one has the right to ignore the sufferings of people who cannot procreate naturally, the medical practice and legal science in our country plead for a formulation of a legal framework in which to apply surrogate motherhood as an infertility treatment, under particular conditions.

  6. Chemical composition and antioxidant activities of essential oils and methanol extracts of three wild Lavandula L. species.

    Science.gov (United States)

    Messaoud, C; Chograni, H; Boussaid, M

    2012-11-01

    A comparative study of essential oil composition, polyphenol content and antioxidant activities of Lavandula coronopifolia, Lavandula multifida and Lavandula stoechas subsp. stoechas were reported. Qualitative and quantitative variations in the composition of oils according to species were shown. Lavandula coronopifolia's oil was characterised by high proportions of trans-β-ocimene (26.9%), carvacrol (18.5%), β-bisabolene (13.1%) and myrcene (7.5%). The main components of L. multifida oil are carvacrol (65.1%) and β-bisabolene (24.7%). Lavandula stoechas oil is rich in fenchone (34.3%) and comphor (27.4%). The total phenolic and flavonoid contents also significantly varied among species. Lavandula coronopifolia exhibits the highest phenolic and flavonoid contents (31.3 mg GAE g(-1) and 16.3 mg RE g(-1), respectively), followed by L. multifida (30.8 mg GAE g(-1) and 12.3 mg RE g(-1)). Methanolic extracts and essential oils displayed significant antioxidant activities. The level of antioxidant capacity varied according to extracts and species.

  7. Generation and Role of Reactive Oxygen and Nitrogen Species Induced by Plasma, Lasers, Chemical Agents, and Other Systems in Dentistry

    Science.gov (United States)

    Jha, Nayansi; Ryu, Jae Jun

    2017-01-01

    The generation of reactive oxygen and nitrogen species (RONS) has been found to occur during inflammatory procedures, during cell ischemia, and in various crucial developmental processes such as cell differentiation and along cell signaling pathways. The most common sources of intracellular RONS are the mitochondrial electron transport system, NADH oxidase, and cytochrome P450. In this review, we analyzed the extracellular and intracellular sources of reactive species, their cell signaling pathways, the mechanisms of action, and their positive and negative effects in the dental field. In dentistry, ROS can be found—in lasers, photosensitizers, bleaching agents, cold plasma, and even resin cements, all of which contribute to the generation and prevalence of ROS. Nonthermal plasma has been used as a source of ROS for biomedical applications and has the potential for use with dental stem cells as well. There are different types of dental stem cells, but their therapeutic use remains largely untapped, with the focus currently on only periodontal ligament stem cells. More research is necessary in this area, including studies about ROS mechanisms with dental cells, along with the utilization of reactive species in redox medicine. Such studies will help to provide successful treatment modalities for various diseases. PMID:29204250

  8. Laminar Flame Speeds of Gasoline Surrogates Measured with the Flat Flame Method

    KAUST Repository

    Liao, Y.-H.

    2016-01-27

    © 2016 American Chemical Society. The adiabatic, laminar flame speeds of gasoline surrogates at atmospheric pressure over a range of equivalence ratios of = 0.8-1.3 and unburned gas temperatures of 298-400 K are measured with the flat flame method, which produces a one-dimensional flat flame free of stretch. Surrogates used in the current work are the primary reference fuels (PRFs, mixtures of n-heptane and isooctane), the toluene reference fuels (TRFs, mixtures of toluene and PRFs), and the ethanol reference fuels (ERFs, mixtures of ethanol and PRFs). In general, there is good agreement between the present work and the literature data for single-component fuel and PRF mixtures. Surrogates of TRF mixtures are found to exhibit comparable flame speeds to a real gasoline, while there is discrepancy observed between isooctane and gasoline. Moreover, the laminar flame speeds of TRF mixtures with similar fractions of n-heptane are found to be insensitive to the quantity of toluene in the mixture. Mixtures of ERFs exhibit comparable flame speeds to those of TRFs with similar mole fractions of n-heptane and isooctane.

  9. Ignition of alkane-rich FACE gasoline fuels and their surrogate mixtures

    KAUST Repository

    Sarathy, Mani

    2015-01-01

    Petroleum derived gasoline is the most used transportation fuel for light-duty vehicles. In order to better understand gasoline combustion, this study investigated the ignition propensity of two alkane-rich FACE (Fuels for Advanced Combustion Engines) gasoline test fuels and their corresponding PRF (primary reference fuel) blend in fundamental combustion experiments. Shock tube ignition delay times were measured in two separate facilities at pressures of 10, 20, and 40 bar, temperatures from 715 to 1500 K, and two equivalence ratios. Rapid compression machine ignition delay times were measured for fuel/air mixtures at pressures of 20 and 40 bar, temperatures from 632 to 745 K, and two equivalence ratios. Detailed hydrocarbon analysis was also performed on the FACE gasoline fuels, and the results were used to formulate multi-component gasoline surrogate mixtures. Detailed chemical kinetic modeling results are presented herein to provide insights into the relevance of utilizing PRF and multi-component surrogate mixtures to reproduce the ignition behavior of the alkane-rich FACE gasoline fuels. The two FACE gasoline fuels and their corresponding PRF mixture displayed similar ignition behavior at intermediate and high temperatures, but differences were observed at low temperatures. These trends were mimicked by corresponding surrogate mixture models, except for the amount of heat release in the first stage of a two-stage ignition events, when observed. © 2014 The Combustion Institute.

  10. Determination of partition behavior of organic surrogates between paperboard packaging materials and air.

    Science.gov (United States)

    Triantafyllou, V I; Akrida-Demertzi, K; Demertzis, P G

    2005-06-03

    The suitability of recycled paperboard packaging materials for direct food contact applications is a major area of investigation. Chemical contaminants (surrogates) partitioning between recycled paper packaging and foods may affect the safety and health of the consumer. The partition behavior of all possible organic compounds between cardboards and individual foodstuffs is difficult and too time consuming for being fully investigated. Therefore it may be more efficient to determine these partition coefficients indirectly through experimental determination of the partitioning behavior between cardboard samples and air. In this work, the behavior of organic pollutants present in a set of two paper and board samples intended to be in contact with foods was studied. Adsorption isotherms have been plotted and partition coefficients between paper and air have been calculated as a basis for the estimation of their migration potential into food. Values of partition coefficients (Kpaper/air) from 47 to 1207 were obtained at different temperatures. For the less volatile surrogates such as dibutyl phthalate and methyl stearate higher Kpaper/air values were obtained. The adsorption curves showed that the more volatile substances are partitioning mainly in air phase and increasing the temperature from 70 to 100 degrees C their concentrations in air (Cair) have almost doubled. The analysis of surrogates was performed with a method based on solvent extraction and gas chromatographic-flame ionization detection (GC-FID) quantification.

  11. Mother-daughter in vitro fertilization triplet surrogate pregnancy.

    Science.gov (United States)

    Michelow, M C; Bernstein, J; Jacobson, M J; McLoughlin, J L; Rubenstein, D; Hacking, A I; Preddy, S; Van der Wat, I J

    1988-02-01

    A successful triplet pregnancy has been established in a surrogate gestational mother following the transfer of five embryos fertilized in vitro. The oocytes were donated by her biological daughter, and the sperm obtained from the daughter's husband. The daughter's infertility followed a total abdominal hysterectomy performed for a postpartum hemorrhage as a result of a placenta accreta. Synchronization of both their menstrual cycles was obtained using oral contraceptive suppression for 2 months, followed by stimulation of both the surrogate gestational mother and her daughter such that embryo transfer would occur at least 48 hr after the surrogate gestational mother's own ovulation. This case raises a number of medical, social, psychological, and ethical issues.

  12. Limitations of habitats as biodiversity surrogates for conservation planning in estuaries.

    Science.gov (United States)

    Shokri, Mohammad Reza; Gladstone, William

    2013-04-01

    Increasing pressures on global biodiversity and lack of data on the number and abundance of species have motivated conservation planners and researchers to use more readily available information as proxies or surrogates for biodiversity. "Habitat" is one of the most frequently used surrogates but its assumed value in marine conservation planning is not often tested. The present study developed and tested three alternative habitat classification schemes of increasing complexity for a large estuary in south-east Australia and tested their effectiveness in predicting spatial variation in macroinvertebrate biodiversity and selecting estuarine protected areas to represent species. The three habitat classification schemes were: (1) broad-scale habitats (e.g., mangroves and seagrass), (2) subdivision of each broad-scale habitat by a suite of environmental variables that varied significantly throughout the estuary, and (3) subdivision of each broad-scale habitat by the subset of environmental variables that best explained spatial variation in macroinvertebrate biodiversity. Macroinvertebrate assemblages differed significantly among the habitats in each classification scheme. For each classification scheme, habitat richness was significantly correlated with species richness, total density of macroinvertebrates, assemblage dissimilarity, and summed irreplaceability. However, in a reserve selection process designed to represent examples of each habitat, no habitat classification scheme represented species significantly better than a random selection of sites. Habitat classification schemes may represent variation in estuarine biodiversity; however, the results of this study suggest they are inefficient in designing representative networks of estuarine protected areas.

  13. Chemical composition and in vitro antimicrobial activity of the essential oils of two Helichrysum species from Tanzania.

    Science.gov (United States)

    Bougatsos, Christos; Ngassapa, Olipa; Runyoro, Deborah K B; Chinou, Ioanna B

    2004-01-01

    The chemical composition of the essential oils obtained from the aerial parts of Helichrysum cymosum and H. fulgidum, from Tanzania, were analyzed by GC and GC/MS. A total of sixty-five compounds, representing 92.4% and 88.2% of the two oils, respectively, were identified. trans-Caryophyllene, caryophyllene oxide, beta-pinene, p-cymene, spathulenol and beta-bourbonene were found to be the main components. Furthermore, the oils were tested against six gram (+/-) bacteria and three pathogenic fungi. It was found that the oil of H. fulgidum exhibited significant antimicrobial activity, while the oil of H. cymosum was not active at all.

  14. The Use of Surrogate Data in Demographic Population Viability Analysis: A Case Study of California Sea Lions.

    Directory of Open Access Journals (Sweden)

    Claudia J Hernández-Camacho

    Full Text Available Reliable data necessary to parameterize population models are seldom available for imperiled species. As an alternative, data from populations of the same species or from ecologically similar species have been used to construct models. In this study, we evaluated the use of demographic data collected at one California sea lion colony (Los Islotes to predict the population dynamics of the same species from two other colonies (San Jorge and Granito in the Gulf of California, Mexico, for which demographic data are lacking. To do so, we developed a stochastic demographic age-structured matrix model and conducted a population viability analysis for each colony. For the Los Islotes colony we used site-specific pup, juvenile, and adult survival probabilities, as well as birth rates for older females. For the other colonies, we used site-specific pup and juvenile survival probabilities, but used surrogate data from Los Islotes for adult survival probabilities and birth rates. We assessed these models by comparing simulated retrospective population trajectories to observed population trends based on count data. The projected population trajectories approximated the observed trends when surrogate data were used for one colony but failed to match for a second colony. Our results indicate that species-specific and even region-specific surrogate data may lead to erroneous conservation decisions. These results highlight the importance of using population-specific demographic data in assessing extinction risk. When vital rates are not available and immediate management actions must be taken, in particular for imperiled species, we recommend the use of surrogate data only when the populations appear to have similar population trends.

  15. The Use of Surrogate Data in Demographic Population Viability Analysis: A Case Study of California Sea Lions

    Science.gov (United States)

    2015-01-01

    Reliable data necessary to parameterize population models are seldom available for imperiled species. As an alternative, data from populations of the same species or from ecologically similar species have been used to construct models. In this study, we evaluated the use of demographic data collected at one California sea lion colony (Los Islotes) to predict the population dynamics of the same species from two other colonies (San Jorge and Granito) in the Gulf of California, Mexico, for which demographic data are lacking. To do so, we developed a stochastic demographic age-structured matrix model and conducted a population viability analysis for each colony. For the Los Islotes colony we used site-specific pup, juvenile, and adult survival probabilities, as well as birth rates for older females. For the other colonies, we used site-specific pup and juvenile survival probabilities, but used surrogate data from Los Islotes for adult survival probabilities and birth rates. We assessed these models by comparing simulated retrospective population trajectories to observed population trends based on count data. The projected population trajectories approximated the observed trends when surrogate data were used for one colony but failed to match for a second colony. Our results indicate that species-specific and even region-specific surrogate data may lead to erroneous conservation decisions. These results highlight the importance of using population-specific demographic data in assessing extinction risk. When vital rates are not available and immediate management actions must be taken, in particular for imperiled species, we recommend the use of surrogate data only when the populations appear to have similar population trends. PMID:26413746

  16. A Large-Scale Study of Surrogate Physicality and Gesturing on Human–Surrogate Interactions in a Public Space

    Directory of Open Access Journals (Sweden)

    Kangsoo Kim

    2017-07-01

    Full Text Available Technological human surrogates, including robotic and virtual humans, have been popularly used in various scenarios, including training, education, and entertainment. Prior research has investigated the effects of the surrogate’s physicality and gesturing in human perceptions and social influence of the surrogate. However, those studies have been carried out in research laboratories, where the participants were aware that it was an experiment, and the participant demographics are typically relatively narrow—e.g., college students. In this paper, we describe and share results from a large-scale exploratory user study involving 7,685 people in a public space, where they were unaware of the experimental nature of the setting, to investigate the effects of surrogate physicality and gesturing on their behavior during human–surrogate interactions. We evaluate human behaviors using several variables, such as proactivity and reactivity, and proximity. We have identified several interesting phenomena that could lead to hypotheses developed as part of future hypothesis-based studies. Based on the measurements of the variables, we believe people are more likely to be engaged in a human–surrogate interaction when the surrogate is physically present, but movements and gesturing with its body parts have not shown the expected benefits for the interaction engagement. Regarding the demographics of the people in the study, we found higher overall engagement for females than males, and higher reactivity for younger than older people. We discuss implications for practitioners aiming to design a technological surrogate that will directly interact with real humans.

  17. A Multi-Fidelity Surrogate Model for the Equation of State for Mixtures of Real Gases

    Science.gov (United States)

    Ouellet, Frederick; Park, Chanyoung; Koneru, Rahul; Balachandar, S.; Rollin, Bertrand

    2017-11-01

    The explosive dispersal of particles is a complex multiphase and multi-species fluid flow problem. In these flows, the products of detonated explosives must be treated as real gases while the ideal gas equation of state is used for the ambient air. As the products expand outward, they mix with the air and create a region where both state equations must be satisfied. One of the most accurate, yet expensive, methods to handle this problem is an algorithm that iterates between both state equations until both pressure and thermal equilibrium are achieved inside of each computational cell. This work creates a multi-fidelity surrogate model to replace this process. This is achieved by using a Kriging model to produce a curve fit which interpolates selected data from the iterative algorithm. The surrogate is optimized for computing speed and model accuracy by varying the number of sampling points chosen to construct the model. The performance of the surrogate with respect to the iterative method is tested in simulations using a finite volume code. The model's computational speed and accuracy are analyzed to show the benefits of this novel approach. This work was supported by the U.S. Department of Energy, National Nuclear Security Administration, Advanced Simulation and Computing Program, as a Cooperative Agreement under the Predictive Science Academic Alliance Program, under Contract No. DE-NA00023.

  18. Surrogate Motherhood: A Trust-Based Approach.

    Science.gov (United States)

    Beier, Katharina

    2015-12-01

    Because it is often argued that surrogacy should not be treated as contractual, the question arises in which terms this practice might then be couched. In this article, I argue that a phenomenology of surrogacy centering on the notion of trust provides a description that is illuminating from the moral point of view. My thesis is that surrogacy establishes a complex and extended reproductive unit--the "surrogacy triad" consisting of the surrogate mother, the child, and the intending parents--whose constituents are bound together by mutual trustful commitments. Even though a trust-based approach does not provide an ultimate answer to whether surrogacy should be sanctioned or prohibited, it allows for at least some practical suggestions. In particular, I will argue that, under certain conditions, surrogacy is tenable within familial or other significant relationships, and I will stress the necessity of acknowledging the new relationships and moral commitments that result from this practice. © The Author 2015. Published by Oxford University Press, on behalf of the Journal of Medicine and Philosophy Inc. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. SURROGATE MOTHER DALAM PERSPEKTIF HUKUM PIDANA INDONESIA

    Directory of Open Access Journals (Sweden)

    Mr. Muntaha

    2013-04-01

    Full Text Available The development of science and technology, in particular in the field of health, has already recently brought a huge advantage and problem in human life. An example of technological marvel that not only requires deep legal thoughts but also at the same time solution is the bio-medical technology advancement of surrogacy. Surrogacy deals with human’s inclination towards reproductive activity. However, it opens up legal complication, in particular with regards to the potential commission of a criminal action as well as to the notion of doctor’s liability. Perkembangan ilmu dan teknologi di bidang kesehatan yang semakin maju dan pesat telah membawa berbagai manfaat dan masalah dalam kehidupan manusia dewasa ini. Salah satu perkembangan yang tidak hanya membutuhkan pemikiran di bidang hukum, tetapi juga sekaligus solusinya adalah mengenai kecanggihan teknologi bio-medis surrogate mother. Surrogacy menyentuh sisi kemanusiaan seorang insan terhadap reproduksi. Akan tetapi, lembaga surrogacy juga membawa komplikasi hukum terutama terkait dengan potensi tindak pidana dan dengan persoalan tanggung jawab dokter.

  20. Polynomial Chaos Surrogates for Bayesian Inference

    KAUST Repository

    Le Maitre, Olivier

    2016-01-06

    The Bayesian inference is a popular probabilistic method to solve inverse problems, such as the identification of field parameter in a PDE model. The inference rely on the Bayes rule to update the prior density of the sought field, from observations, and derive its posterior distribution. In most cases the posterior distribution has no explicit form and has to be sampled, for instance using a Markov-Chain Monte Carlo method. In practice the prior field parameter is decomposed and truncated (e.g. by means of Karhunen- Lo´eve decomposition) to recast the inference problem into the inference of a finite number of coordinates. Although proved effective in many situations, the Bayesian inference as sketched above faces several difficulties requiring improvements. First, sampling the posterior can be a extremely costly task as it requires multiple resolutions of the PDE model for different values of the field parameter. Second, when the observations are not very much informative, the inferred parameter field can highly depends on its prior which can be somehow arbitrary. These issues have motivated the introduction of reduced modeling or surrogates for the (approximate) determination of the parametrized PDE solution and hyperparameters in the description of the prior field. Our contribution focuses on recent developments in these two directions: the acceleration of the posterior sampling by means of Polynomial Chaos expansions and the efficient treatment of parametrized covariance functions for the prior field. We also discuss the possibility of making such approach adaptive to further improve its efficiency.

  1. Heavy metals in atmospheric surrogate dry deposition

    Science.gov (United States)

    Morselli; Cecchini; Grandi; Iannuccilli; Barilli; Olivieri

    1999-02-01

    This paper describes a methodological approach for the assessment of the amount of surrogate dry deposition of several toxic heavy metals (Cd, Cr, Cu, Ni, Pb, V, Zn) associated with atmospheric particulate matter at ground level. The objectives of the study were twofold: i) the evaluation of several techniques for the digestion of dry deposition samples for trace metal analysis; ii) the comparison of the results from two samplers with different collecting surfaces. A dry solid surface sampler (DRY sampler, Andersen--USA) and a water layer surface sampler (DAS sampler--MTX Italy) were employed. The samples were collected over a one-year period in an urban site of Bologna (northern Italy). A description is given of the complete procedure, from sampling to data elaboration, including sample storage, digestion and analytical methods. According to the results obtained with three different digestion techniques (Teflon bomb, microwave digester and Teflon flask with vapour cooling system), the highest recovery rate was achieved by the Teflon bomb procedure employing an NBS 1648 Standard Reference Material; 90-95% of the elements considered were recovered by dissolution in a pressurized Teflon bomb with an HNO3-HF mixture. Given these results, the technique was adopted for dry deposition sample digestion. On the basis of the amount of heavy metals measured as monthly deposition fluxes (microg/m2), the collecting efficiency of the DAS sampler for a number of elements was found to be as much as two to three times greater than that of the DRY sampler.

  2. Spectroscopic studies of neutral and chemically oxidized species of β-carotene, lycopene and norbixin in CH2Cl2: Fluorescence from intermediate compounds

    International Nuclear Information System (INIS)

    Alwis, D.D.D.H; Chandrika, U.G.; Jayaweera, P.M.

    2015-01-01

    Radical cations, dications and oxidized intermediate species of three carotenoids, namely, β-carotene, lycopene and norbixin, were generated in CH 2 Cl 2 solutions via chemical oxidation using anhydrous FeCl 3 . UV–vis, fluorescence and fluorescence-excitation spectroscopic studies were performed to understand and compare the nature of intermediate species generated during the chemical oxidation process and subsequent degradation. The intense emission observed at 550 nm can be assigned to the S 2 →S 0 (1 1 B u →1 1 A g ) transition of the carotenoid molecules. The 350 nm excitation during the oxidation process for β-carotene, lycopene and norbixin exhibit intense fluorescence peaks at 492 nm, 493 nm and 500 nm, respectively. These peaks are assigned to intermediate peroxy/epoxy compounds of the three molecules that are formed with molecular oxygen prior to the formation of oxidized short-chain stable compounds. - Highlights: • Fluorescence and UV–vis studies on β-carotene, lycopene and norbixin. • Oxidation, induced by FeCl 3 in CH 2 Cl 2 shows blue shifted fluorescence peaks. • Fluorescence peaks were assigned to intermediate peroxy/epoxy forms of carotenoids. • The D0→D3 transition of radical cations are observed in the near IR region

  3. Future needs and recommendations in the development of species sensitivity distributions: Estimating toxicity thresholds for aquatic ecological communities and assessing impacts of chemical exposures.

    Science.gov (United States)

    Belanger, Scott; Barron, Mace; Craig, Peter; Dyer, Scott; Galay-Burgos, Malyka; Hamer, Mick; Marshall, Stuart; Posthuma, Leo; Raimondo, Sandy; Whitehouse, Paul

    2017-07-01

    A species sensitivity distribution (SSD) is a probability model of the variation of species sensitivities to a stressor, in particular chemical exposure. The SSD approach has been used as a decision support tool in environmental protection and management since the 1980s, and the ecotoxicological, statistical, and regulatory basis and applications continue to evolve. This article summarizes the findings of a 2014 workshop held by the European Centre for Toxicology and Ecotoxicology of Chemicals and the UK Environment Agency in Amsterdam, The Netherlands, on the ecological relevance, statistical basis, and regulatory applications of SSDs. An array of research recommendations categorized under the topical areas of use of SSDs, ecological considerations, guideline considerations, method development and validation, toxicity data, mechanistic understanding, and uncertainty were identified and prioritized. A rationale for the most critical research needs identified in the workshop is provided. The workshop reviewed the technical basis and historical development and application of SSDs, described approaches to estimating generic and scenario-specific SSD-based thresholds, evaluated utility and application of SSDs as diagnostic tools, and presented new statistical approaches to formulate SSDs. Collectively, these address many of the research needs to expand and improve their application. The highest priority work, from a pragmatic regulatory point of view, is to develop a guidance of best practices that could act as a basis for global harmonization and discussions regarding the SSD methodology and tools. Integr Environ Assess Manag 2017;13:664-674. © 2016 SETAC. © 2016 SETAC.

  4. Spectroscopic studies of neutral and chemically oxidized species of β-carotene, lycopene and norbixin in CH{sub 2}Cl{sub 2}: Fluorescence from intermediate compounds

    Energy Technology Data Exchange (ETDEWEB)

    Alwis, D.D.D.H [Department of Chemistry, The Open University of Sri Lanka, Nawala (Sri Lanka); Department of Chemistry, University of Sri Jayewardenepura, Nugegoda (Sri Lanka); Chandrika, U.G. [Department of Biochemistry, University of Sri Jayewardenepura, Nugegoda (Sri Lanka); Jayaweera, P.M., E-mail: pradeep@sjp.ac.lk [Department of Chemistry, University of Sri Jayewardenepura, Nugegoda (Sri Lanka)

    2015-02-15

    Radical cations, dications and oxidized intermediate species of three carotenoids, namely, β-carotene, lycopene and norbixin, were generated in CH{sub 2}Cl{sub 2} solutions via chemical oxidation using anhydrous FeCl{sub 3}. UV–vis, fluorescence and fluorescence-excitation spectroscopic studies were performed to understand and compare the nature of intermediate species generated during the chemical oxidation process and subsequent degradation. The intense emission observed at 550 nm can be assigned to the S{sub 2}→S{sub 0} (1{sup 1}B{sub u}→1{sup 1}A{sub g}) transition of the carotenoid molecules. The 350 nm excitation during the oxidation process for β-carotene, lycopene and norbixin exhibit intense fluorescence peaks at 492 nm, 493 nm and 500 nm, respectively. These peaks are assigned to intermediate peroxy/epoxy compounds of the three molecules that are formed with molecular oxygen prior to the formation of oxidized short-chain stable compounds. - Highlights: • Fluorescence and UV–vis studies on β-carotene, lycopene and norbixin. • Oxidation, induced by FeCl{sub 3} in CH{sub 2}Cl{sub 2} shows blue shifted fluorescence peaks. • Fluorescence peaks were assigned to intermediate peroxy/epoxy forms of carotenoids. • The D0→D3 transition of radical cations are observed in the near IR region.

  5. CHEMICAL CHARACTERIZATION OF Lavandula angustifolia Mill. WHICH IS A PHYTOCOSMETIC SPECIES AND INVESTIGATION OF ITS ANTIMICROBIAL EFFECT IN COSMETIC PRODUCTS

    Directory of Open Access Journals (Sweden)

    Aslıhan Cesur Turgut

    2016-11-01

    Full Text Available Lavander (Lavandula sp. is a precious essential oil plant from the Lamiaceae family. There are 39 lavender species (Lavandula sp. most of which have Mediterranean origin and among them three have high commercial value. While the essential oil quality of the lavender species (British lavender is high the lavandin species (hybrid lavender have high essential oil yield [2, 52]. In this study, the content of the extracts obtained from Lavandula angustifolia, which were grown in Burdur Örtülü locality, was determined via HPLC and GC analysis and the anti-microbial effect of the essential oil L. angustifolia was investigated. The study was made with the dried flowers of L. angustifolia. Some of the dried flowers were extracted and the essential oil was distilled from the remaining part. Various phenolic compounds in the extract were quantitatively determined by HPLC. Quantitatively cafeic, rosemeric and the 4-hydroxybenzoic acids were the most abundant phenolic acids in the content in decreasing order. In the GC analysis 31 different compounds were determined: Linalool and Linalil Acetate having the highest concentration. Anti-microbial effect was determined against the most frequently encountered microorganisms in the cosmetics: Candida albicans, Staphylococcus aureus, Pseudomonas aeruginosa, Aspergillus brasiliensis. According to the results it is concluded that the essential oil, L. angustifolia, can be used either directly or incorporated into the cosmetics without the necessity for any other extra preservative against the said microrganisms. According to the literature these microorganisms, which are frequently found in creams, cause various diseases. It was observed that the essential oil L. Angustifolia could completely remove the contamination caused by the said micro-organisms as of the 14. day.

  6. Regulation of redox reactions of chemical species (arsenic and chromium) in sediment of Marque river. From experimentation to modeling

    International Nuclear Information System (INIS)

    Gorny, Josselin

    2015-01-01

    The French national radioactive waste management agency (Andra) and the Nord-Pas de Calais (NPDC) Region aim to better understand the fate of the redox sensitive trace elements in soils and river sediments to ameliorate the management of polluted sediments and of the storage of radioactive wastes. To address this problematic, some river sediments were selected as proxies, as strong redox gradients can be observed. Two methods have been developed to study the speciation of As and Cr: (i) HPIC-ICP-MS (High Performance Ionic Performance - Inductively Coupled Plasma - Mass Spectrometry) coupling in order to separate and quantify As [As(III), As(V), DMMA V and MMAA V ] and Cr species [Cr(III) and Cr(VI)], and (ii) DGT probes (Diffusive Gradient in Thin Film) containing specific chelating binding gels to quantify As species [As(III) and total As]. These methods have been implemented to monitor the low contaminated pore waters of the Marque river during 9 months. The results demonstrated that chromium is present only under its reduced form Cr(III), which makes difficult to assess the parameters that force redox interconversions between Cr(III) and Cr(VI). Arsenic is present only under its inorganic forms: As(III), As(V), and thio-arsenical species. Seasonal changes of As speciation in the dissolved phase depends mainly of S(-II) production by sulfate-reducing bacteria, which makes the amount of dissolved S(- II) an important parameter to follow through time since the As reduction increases its mobility and toxicity. (author) [fr

  7. Determination of the sources of the airborne physico-chemical 131I species in a PWR power plant

    International Nuclear Information System (INIS)

    Deuber, H.; Wilhelm, J.G.

    1978-01-01

    In a 1300 MWE PWR power plant the sources of the airborne 131 I species were determined over a period of 5 months. During power operation the main source of the radiologically decisive elemental 131 I was the exhaust from the hoods in which samples from the primary coolant are taken and processed. During refueling outage elemental 131 I was mainly contributed by the containment purge air. By efficient filtration of these exhausts, a reduction of the ingestion dose, caused by the total 131 I stack release, by a factor of nearly 4 during power operation and of possibly 10 during refueling outage can be accomplished. (author)

  8. Quantification of chemical sulphur species in bulk soil and organic sulphur fractions by S K-edge Xanes spectroscopy

    DEFF Research Database (Denmark)

    Boye, K; Almkvist, G; Nilsson, S I

    2011-01-01

    residue (CR) incorporation and farmyard manure (FYM) application, with equal applications of mineral nutrients were included in the study. In the new data treatment method, internally calibrated spectra of dilute solutions (30 mm) of model compounds were used to fit the sample spectra. This greatly...... the opposite trend was observed. Sulphur XANES spectroscopy of acetylacetone extracts of physically protected and unprotected organic S in two of the soils revealed that physical protection was not related to S speciation; however, intermediate forms of oxidized S species appeared to accumulate in the residual...

  9. Improving the chemical compatibility of sealing glass for solid oxide fuel cells: Blocking the reactive species by controlled crystallization

    Science.gov (United States)

    Zhang, Teng; Zou, Qi; Zeng, Fanrong; Wang, Shaorong; Tang, Dian; Yang, Hiswen

    2012-10-01

    The chemical compatibility of sealing glass is of great importance for Solid oxide fuel cell (SOFC). In this work, the interfacial reaction between sealing glass and Cr-containing interconnect alloy is characterized by reacting Cr2O3 powders with a representative SrO-containing glass crystallized by different heat-treatment schedules. The crystalline structure and crystalline content of sealing glass are determined by X-ray diffraction. The results show that the fraction of Cr6+ decreases from 39.8 ± 1.9% for quenched glass to 8.2 ± 0.4% for glass crystallized at 900 °C for 2 h. In addition, the interfacial reaction can be further reduced with increasing crystallization temperature and time as well as the addition of nucleation agent (TiO2). The formation of some Sr-containing crystalline phases, Sr2SiO4 and Sr(TiO3), contributes to the improvement of chemical compatibility of sealing glass, in agreement with the results of thermodynamic calculations.

  10. Chemical modeling of groundwater in the Banat Plain, southwestern Romania, with elevated As content and co-occurring species by combining diagrams and unsupervised multivariate statistical approaches.

    Science.gov (United States)

    Butaciu, Sinziana; Senila, Marin; Sarbu, Costel; Ponta, Michaela; Tanaselia, Claudiu; Cadar, Oana; Roman, Marius; Radu, Emil; Sima, Mihaela; Frentiu, Tiberiu

    2017-04-01

    The study proposes a combined model based on diagrams (Gibbs, Piper, Stuyfzand Hydrogeochemical Classification System) and unsupervised statistical approaches (Cluster Analysis, Principal Component Analysis, Fuzzy Principal Component Analysis, Fuzzy Hierarchical Cross-Clustering) to describe natural enrichment of inorganic arsenic and co-occurring species in groundwater in the Banat Plain, southwestern Romania. Speciation of inorganic As (arsenite, arsenate), ion concentrations (Na + , K + , Ca 2+ , Mg 2+ , HCO 3 - , Cl - , F - , SO 4 2- , PO 4 3- , NO 3 - ), pH, redox potential, conductivity and total dissolved substances were performed. Classical diagrams provided the hydrochemical characterization, while statistical approaches were helpful to establish (i) the mechanism of naturally occurring of As and F - species and the anthropogenic one for NO 3 - , SO 4 2- , PO 4 3- and K + and (ii) classification of groundwater based on content of arsenic species. The HCO 3 - type of local groundwater and alkaline pH (8.31-8.49) were found to be responsible for the enrichment of arsenic species and occurrence of F - but by different paths. The PO 4 3- -AsO 4 3- ion exchange, water-rock interaction (silicates hydrolysis and desorption from clay) were associated to arsenate enrichment in the oxidizing aquifer. Fuzzy Hierarchical Cross-Clustering was the strongest tool for the rapid simultaneous classification of groundwaters as a function of arsenic content and hydrogeochemical characteristics. The approach indicated the Na + -F - -pH cluster as marker for groundwater with naturally elevated As and highlighted which parameters need to be monitored. A chemical conceptual model illustrating the natural and anthropogenic paths and enrichment of As and co-occurring species in the local groundwater supported by mineralogical analysis of rocks was established. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Differential Biofilm Formation and Chemical Disinfection Resistance of Sessile Cells of Listeria monocytogenes Strains under Monospecies and Dual-Species (with Salmonella enterica) Conditions

    Science.gov (United States)

    Kostaki, Maria; Chorianopoulos, Nikos; Braxou, Elli; Nychas, George-John

    2012-01-01

    This study aimed to investigate the possible influence of bacterial intra- and interspecies interactions on the ability of Listeria monocytogenes and Salmonella enterica to develop mixed-culture biofilms on an abiotic substratum, as well as on the subsequent resistance of sessile cells to chemical disinfection. Initially, three strains from each species were selected and left to attach and form biofilms on stainless steel (SS) coupons incubated at 15°C for 144 h, in periodically renewable tryptone soy broth (TSB), under either monoculture or mixed-culture (mono-/dual-species) conditions. Following biofilm formation, mixed-culture sessile communities were subjected to 6-min disinfection treatments with (i) benzalkonium chloride (50 ppm), (ii) sodium hypochlorite (10 ppm), (iii) peracetic acid (10 ppm), and (iv) a mixture of hydrogen peroxide (5 ppm) and peracetic acid (5 ppm). Results revealed that both species reached similar biofilm counts (ca. 105 CFU cm−2) and that, in general, interspecies interactions did not have any significant effect either on the biofilm-forming ability (as this was assessed by agar plating enumeration of the mechanically detached biofilm bacteria) or on the antimicrobial resistance of each individual species. Interestingly, pulsed-field gel electrophoresis (PFGE) analysis clearly showed that the three L. monocytogenes strains did not contribute at the same level either to the formation of mixed-culture sessile communities (mono-/dual species) or to their antimicrobial recalcitrance. Additionally, the simultaneous existence inside the biofilm structure of S. enterica cells seemed to influence the occurrence and resistance pattern of L. monocytogenes strains. In sum, this study highlights the impact of microbial interactions taking place inside a mixed-culture sessile community on both its population dynamics and disinfection resistance. PMID:22307304

  12. Chemical speciation of arsenic species in human blood serum by liquid chromatography using a phosphatidylcholine-coated ODS column with detection by ICP-MS

    International Nuclear Information System (INIS)

    Hasegawa, Takuya; Ishise, Jotaro; Fukumoto, Yasuharu; Matsuura, Hirotaka; Zhu, Yanbei; Umemura, Tomonari; Haraguchi, Hiroki; Yamamoto, Kazuhito; Naoe, Tomoki

    2007-01-01

    Chemical speciation of arsenic species in human blood serum was performed by high-performance liquid chromatography/inductively coupled plasma mass spectrometry (HPLC/ICP-MS) with direct sample injection, where an octadecylsilyl silica (ODS) column coated with phosphatidylcholine (PC) (hereafter known as 'PC-coated ODS column') was used as the separation column. In arsenic species analysis, a citrate buffer solution (pH 4.0) was used as the mobile phase, in which the following reagents were added: sodium 1-dodecanesulfonate (SDS), tetramethylammonium hydroxide (TMAH), which are ion-pair reagents to separate inorganic and organic arsenic species, and 3-[(3-cholamidopropyl)-dimethylammonio]-1-propane sulfonate (CHAPS), which is a protein-solubilizing agent to prevent adsorption of proteins on the column. As a result of optimization, five representative arsenic species spiked in human blood serum reference material could be separated from each other within 5 min on the PC-coated ODS column by elution with a 5 mM citrate buffer (pH 4.0) containing 5 mM SDS, 5 mM THAH, and 0.2 mM CHAPS. The detection limits obtained by ICP-MS were 3.1, 2.7, 4.5, 2.5, and 2.5 ng of As g -1 for arsenate (iAs V ), arsenite (iAs III ), monomethylarsonic acid (MMA), dimethylarsenic acid (DMA), and arsenobetaine (AB), respectively, when the injection volume was 20 μL. The present separation system was also applied to speciation analysis of arsenic species in human blood serum collected from a leukemia patient after therapeutic treatment with arsenic. (author)

  13. Growing Azolla to produce sustainable protein feed: the effect of differing species and CO2 concentrations on biomass productivity and chemical composition.

    Science.gov (United States)

    Brouwer, Paul; Schluepmann, Henriette; Nierop, Klaas Gj; Elderson, Janneke; Bijl, Peter K; van der Meer, Ingrid; de Visser, Willem; Reichart, Gert-Jan; Smeekens, Sjef; van der Werf, Adrie

    2018-03-24

    Since available arable land is limited and nitrogen fertilizers pollute the environment, cropping systems ought to be developed that do not rely on them. Here we investigate the rapidly growing, N 2 -fixing Azolla/Nostoc symbiosis for its potential productivity and chemical composition to determine its potential as protein feed. In a small production system, cultures of Azolla pinnata and Azolla filiculoides were continuously harvested for over 100 days, yielding an average productivity of 90.0-97.2 kg dry weight (DW) ha -1  d -1 . Under ambient CO 2 levels, N 2 fixation by the fern's cyanobacterial symbionts accounted for all nitrogen in the biomass. Proteins made up 176-208 g kg -1 DW (4.9 × total nitrogen), depending on species and CO 2 treatment, and contained more essential amino acids than protein from soybean. Elevated atmospheric CO 2 concentrations (800 ppm) significantly boosted biomass production by 36-47%, without decreasing protein content. Choice of species and CO 2 concentrations further affected the biomass content of lipids (79-100 g kg -1 DW) and (poly)phenols (21-69 g kg -1 DW). By continuous harvesting, high protein yields can be obtained from Azolla cultures, without the need for nitrogen fertilization. High levels of (poly)phenols likely contribute to limitations in the inclusion rate of Azolla in animal diets and need further investigation. © 2018 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2018 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

  14. Essential Oils Extracted Using Microwave-Assisted Hydrodistillation from Aerial Parts of Eleven Artemisia Species: Chemical Compositions and Diversities in Different Geographical Regions of Iran

    Directory of Open Access Journals (Sweden)

    Majid Mohammadhosseini

    2017-03-01

    Full Text Available This study aimed to assess the chemical compositions of essential oils (EOs extracted through microwave-assisted hydrodistillation from aerial parts of 11 Artemisia species growing wild in different regions in Northern, Eastern, Western, and Central parts of Iran. The EOs were subsequently analyzed via GC and GC-MS. The percentage yields of the EOs varied over the range of 0.21-0.50 (w/w%. On the basis of these characterizations and spectral assignments, natural compounds including camphor, 1,8-cineole, camphene, α-pinene, β-pinene, β-thujone, and sabinene were the most abundant and frequent constituents among all studied chemical profiles. Accordingly, oxygenated monoterpenes, monoterpene hydrocarbons, and non-terpene hydrocarbons were the dominant groups of natural compounds in the chemical profiles of 13, 4, and 2 samples, respectively. Moreover, five chemotypes were identified using statistical analyses: camphene, α-pinene and β-pinene; 1,8-cineole; camphore and 1,8-cineole; camphore and camphore and β-thujone.

  15. A Parallel and Distributed Surrogate Model Implementation for Computational Steering

    KAUST Repository

    Butnaru, Daniel; Buse, Gerrit; Pfluger, Dirk

    2012-01-01

    of the input parameters. Such an exploration process is however not possible if the simulation is computationally too expensive. For these cases we present in this paper a scalable computational steering approach utilizing a fast surrogate model as substitute

  16. Altruistic surrogacy: the necessary objectification of surrogate mothers.

    Science.gov (United States)

    Tieu, M M

    2009-03-01

    One of the major concerns about surrogacy is the potential harm that may be inflicted upon the surrogate mother and the child after relinquishment. Even if one were to take the liberal view that surrogacy should be presumptively allowed on the basis of autonomy and/or compassion, evidence of harm must be taken seriously. In this paper I review the evidence from psychological studies on the effect that relinquishing a child has on the surrogate mother and while it appears that many surrogates are able to cope with relinquishment, I argue that there are good reasons, grounded in empirical evidence, to support the view that the subsequent management of the relinquishment necessarily objectifies the surrogate mother.

  17. Hepatology may have problems with putative surrogate outcome measures

    DEFF Research Database (Denmark)

    Gluud, Christian; Brok, Jesper; Gong, Yan

    2007-01-01

    A surrogate outcome measure is a laboratory measurement, a physical sign, or another intermediate substitute that is able to predict an intervention's effect on a clinically meaningful outcome. A clinical outcome detects how a patient feels, functions, or survives. Surrogate outcome measures occur...... faster or more often, are cheaper, and/or are less invasively achieved than the clinical outcome. In practice, validation is surprisingly often overlooked, especially if a biologic plausible rationale is proposed. Surrogate outcomes must be validated before use. The first step in validation...... predicts the intervention's effect on the clinical outcome. In hepatology a number of putative surrogate outcomes are used both in clinical research and in clinical practice without having been properly validated. Sustained virological response to interferons and ribavirin in patients with chronic...

  18. Premixed flame chemistry of a gasoline primary reference fuel surrogate

    KAUST Repository

    Selim, Hatem; Mohamed, Samah; Hansen, Nils; Sarathy, Mani

    2017-01-01

    Investigating the combustion chemistry of gasoline surrogate fuels promises to improve detailed reaction mechanisms used for simulating their combustion. In this work, the combustion chemistry of one of the simplest, but most frequently used

  19. Chemical Kinetic Models for Advanced Engine Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Pitz, William J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mehl, Marco [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Westbrook, Charles K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-10-22

    The objectives for this project are as follows: Develop detailed chemical kinetic models for fuel components used in surrogate fuels for compression ignition (CI), homogeneous charge compression ignition (HCCI) and reactivity-controlled compression-ignition (RCCI) engines; and Combine component models into surrogate fuel models to represent real transportation fuels. Use them to model low-temperature combustion strategies in HCCI, RCCI, and CI engines that lead to low emissions and high efficiency.

  20. The source, discharge, and chemical characteristics of selected springs, and the abundance and health of associated endemic anuran species in the Mojave network parks

    Science.gov (United States)

    Schroeder, Roy A.; Smith, Gregory A.; Martin, Peter; Flint, Alan L.; Gallegos, Elizabeth; Fisher, Robert N.; Martin, Peter; Schroeder, Roy A.

    2015-01-01

    Hydrological and biological investigations were done during 2005 and 2006 in cooperation with the U.S. National Park Service to investigate the source, discharge, and chemical characteristics of selected springs and the abundance and health of endemic anuran (frog and toad) species at Darwin Falls in Death Valley National Park, Piute Spring in Mojave National Preserve, and Fortynine Palms Oasis in Joshua Tree National Park. Discharge from the springs at these sites sustains isolated riparian habitats in the normally dry Mojave Desert. Data were collected on water quantity (discharge) and quality, air and water temperature, and abundance and health of endemic anuran species. In addition, a single survey of the abundance and health of endemic anuran species was completed at Rattlesnake Canyon in Joshua Tree National Park. Results from this study were compared to limited historical data, where they exist, and can provide a baseline for future hydrological and biological investigations to evaluate the health and sustainability of the resource and its response to changing climate and increasing human use.

  1. Emotional experiences in surrogate mothers: A qualitative study

    OpenAIRE

    Ahmari Tehran, Hoda; Tashi, Shohreh; Mehran, Nahid; Eskandari, Narges; Dadkhah Tehrani, Tahmineh

    2014-01-01

    Background: Surrogacy is one of the new techniques of assisted reproduction technology in which a woman carries and bears a child for another woman. In Iran, many Shia clerics and jurists considered it permissible so there is no religious prohibition for it. In addition to the risk of physical complications for complete surrogate mothers, the possibility of psychological complications resulted from emotional attachment to a living creature in the surrogate mother as another injury requires co...

  2. Families in the making: gestational surrogate mothers in California

    OpenAIRE

    Bjørn, Henriette Hårseide

    2014-01-01

    This thesis is based on a field work I conducted in California from January to June 2012, where I explore how gestational surrogate mothers experience the process of surrogacy and how California law has dealt with ART-cases. Through exploring surrogacy from different view point, and in particular from the view of surrogate mothers, this has given an insightful view into surrogacy in California. I have identified two court cases which are important for the establishment of parental rights in s...

  3. Act relating to surrogate parenthood contracts, 10 February 1988.

    Science.gov (United States)

    1988-01-01

    This Nebraska Act provides that surrogate parenthood contracts are void and unenforceable and that the "biological father of a child born pursuant to such a contract shall have all the rights and obligations imposed by law with respect to the child." A surrogate parenthood contract is defined as "a contract by which a woman is to be compensated for bearing a child of a man who is not her husband." full text

  4. Error modeling for surrogates of dynamical systems using machine learning

    Science.gov (United States)

    Trehan, Sumeet; Carlberg, Kevin T.; Durlofsky, Louis J.

    2017-12-01

    A machine-learning-based framework for modeling the error introduced by surrogate models of parameterized dynamical systems is proposed. The framework entails the use of high-dimensional regression techniques (e.g., random forests, LASSO) to map a large set of inexpensively computed `error indicators' (i.e., features) produced by the surrogate model at a given time instance to a prediction of the surrogate-model error in a quantity of interest (QoI). This eliminates the need for the user to hand-select a small number of informative features. The methodology requires a training set of parameter instances at which the time-dependent surrogate-model error is computed by simulating both the high-fidelity and surrogate models. Using these training data, the method first determines regression-model locality (via classification or clustering), and subsequently constructs a `local' regression model to predict the time-instantaneous error within each identified region of feature space. We consider two uses for the resulting error model: (1) as a correction to the surrogate-model QoI prediction at each time instance, and (2) as a way to statistically model arbitrary functions of the time-dependent surrogate-model error (e.g., time-integrated errors). We apply the proposed framework to model errors in reduced-order models of nonlinear oil--water subsurface flow simulations. The reduced-order models used in this work entail application of trajectory piecewise linearization with proper orthogonal decomposition. When the first use of the method is considered, numerical experiments demonstrate consistent improvement in accuracy in the time-instantaneous QoI prediction relative to the original surrogate model, across a large number of test cases. When the second use is considered, results show that the proposed method provides accurate statistical predictions of the time- and well-averaged errors.

  5. Chemical composition and antifungal activity of essential oil of Salvia sclarea L. from Bulgaria against isolates of Candida species

    Directory of Open Access Journals (Sweden)

    Yana Hristova

    2013-01-01

    Full Text Available The essential oil of Salvia sclarea L., growing in Bulgaria, was analyzed by gas chromatography – mass spectrometry. A total of 52 different compounds were identified, representing 98.25% of total oil content. Linalyl acetate (56.88% and linalool (20.75% were determined as major essential oil constituents, followed by germacrene D (5.08% and β-cariophyllene (3.41%. Antifungal activities of clary sage essential oil and major compounds linalyl acetate and linalool against 30 clinical isolates, belonging to species Candida albicans, Candida tropicalis, Candida krusei, Candida glabrata and Candida parapsilosis were evaluated. Essential oil characterized with stronger anticandidial activity in comparison with pure compounds.

  6. Occurrence and spatial distribution of chemical contaminants in edible fish species collected from UK and proximate marine waters.

    Science.gov (United States)

    Fernandes, A R; Mortimer, D; Holmes, M; Rose, M; Zhihua, L; Huang, X; Smith, F; Panton, S; Marshall, L

    2018-05-01

    The occurrence of a range of regulated and emerging organic environmental contaminants was investigated in 182 samples of edible marine fish sampled mainly from UK marine regions, but extending northerly to the coast of Norway and south to the Algarve. These species (sprats, mackerel, turbot, halibut, herring, grey mullet, sea bass, grey mullet, sardines, etc.) are among those considered to be at the highest risk of contamination with regulated contaminants such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, dioxins), and polychlorinated biphenyls (PCBs), but the occurrence of polybrominated diphenylethers (PBDEs) and polybrominated biphenyls (PBBs) was also investigated. Sub-sets of samples (50-75) were also analysed for emerging contaminants: polychlorinated naphthalenes (PCNs), polybrominated and mixed halogenated dibenzo-p-dioxins, dibenzofurans and biphenyls (PBDD/Fs, PXDD/Fs and PXBs) and perfluoroalkyl substances (PFAS). Contaminant occurrence varied with species and location, but all measured contaminants were detected, with sprats, sea bass, sardines, mackerel, and herring showing higher tissue concentrations. The concentrations of the different contaminants in the various samples were mapped utilising the GPS coordinate data of the capture locations to visualise spatial distribution levels. In terms of catch location, fish sampled from the coasts of southern Britain, north-western France and the Irish Sea appeared to contain proportionately higher levels of some contaminants - e.g. samples from the Irish Sea tended to show higher PCN concentrations, whereas higher levels of PCBs were observed in some fish sampled off the coasts of northern France. Similarly, samples of mullet from the southeast coast of UK showed much higher concentrations of BDE-99 than the other regions. In terms of occurrence trends, PCDD/F and PCB concentrations show a modest decline over the last decade but where limited background data is available for emerging

  7. Evaluation and comparison of predictive individual-level general surrogates.

    Science.gov (United States)

    Gabriel, Erin E; Sachs, Michael C; Halloran, M Elizabeth

    2018-07-01

    An intermediate response measure that accurately predicts efficacy in a new setting at the individual level could be used both for prediction and personalized medical decisions. In this article, we define a predictive individual-level general surrogate (PIGS), which is an individual-level intermediate response that can be used to accurately predict individual efficacy in a new setting. While methods for evaluating trial-level general surrogates, which are predictors of trial-level efficacy, have been developed previously, few, if any, methods have been developed to evaluate individual-level general surrogates, and no methods have formalized the use of cross-validation to quantify the expected prediction error. Our proposed method uses existing methods of individual-level surrogate evaluation within a given clinical trial setting in combination with cross-validation over a set of clinical trials to evaluate surrogate quality and to estimate the absolute prediction error that is expected in a new trial setting when using a PIGS. Simulations show that our method performs well across a variety of scenarios. We use our method to evaluate and to compare candidate individual-level general surrogates over a set of multi-national trials of a pentavalent rotavirus vaccine.

  8. Statistical characteristics of surrogate data based on geophysical measurements

    Directory of Open Access Journals (Sweden)

    V. Venema

    2006-01-01

    Full Text Available In this study, the statistical properties of a range of measurements are compared with those of their surrogate time series. Seven different records are studied, amongst others, historical time series of mean daily temperature, daily rain sums and runoff from two rivers, and cloud measurements. Seven different algorithms are used to generate the surrogate time series. The best-known method is the iterative amplitude adjusted Fourier transform (IAAFT algorithm, which is able to reproduce the measured distribution as well as the power spectrum. Using this setup, the measurements and their surrogates are compared with respect to their power spectrum, increment distribution, structure functions, annual percentiles and return values. It is found that the surrogates that reproduce the power spectrum and the distribution of the measurements are able to closely match the increment distributions and the structure functions of the measurements, but this often does not hold for surrogates that only mimic the power spectrum of the measurement. However, even the best performing surrogates do not have asymmetric increment distributions, i.e., they cannot reproduce nonlinear dynamical processes that are asymmetric in time. Furthermore, we have found deviations of the structure functions on small scales.

  9. Improving Communication With Surrogate Decision-Makers: A Pilot Initiative.

    Science.gov (United States)

    Meltzer, Ellen C; Shi, Zhenzhen; Suppes, Alexandra; Hersh, Jennifer E; Orlander, Jay D; Calhoun, Aaron W; Tung, Judy; Logio, Lia; Manna, Ruth; Bialer, Philip A; Acres, Cathleen A; Fins, Joseph J

    2017-08-01

    Difficult conversations in medical care often occur between physicians and patients' surrogates, individuals entrusted with medical decisions for patients who lack the capacity to make them. Poor communication between patients' surrogates and physicians may exacerbate anxiety and guilt for surrogates, and may contribute to physician stress and burnout. This pilot study assesses the effectiveness of an experiential learning workshop that was conducted in a clinical setting, and aimed at improving resident physician communication skills with a focus on surrogate decision-making. From April through June 2016, we assessed internal medicine residents' baseline communication skills through an objective structured clinical examination (OSCE) with actors representing standardized surrogates. After an intensive, 6-hour communication skills workshop, residents were reassessed via an OSCE on the same day. A faculty facilitator and the surrogate evaluated participants' communication skills via the expanded Gap Kalamazoo Consensus Statement Assessment Form. Wilcoxon signed rank tests (α of .05) compared mean pre- and postworkshop scores. Of 44 residents, 33 (75%) participated. Participants' average preworkshop OSCE scores ( M  = 3.3, SD = 0.9) were significantly lower than postworkshop scores ( M  = 4.3; SD = 0.8; Z  = 4.193; P  decision-making benefit from focused interventions. Our pilot assessment of a workshop showed promise, and additionally demonstrated the feasibility of bringing OSCEs and simulated encounters into a busy clinical practice.

  10. Characterization of the parameters at the origin of the chemical species hideout process at the fuel rod surface in boiling conditions

    International Nuclear Information System (INIS)

    Peybernes, J.; March, P.

    1999-01-01

    Current trends in nuclear power generation (and particularly in pressurized water reactors) are toward plant life extension and extended fuel burnup. A higher heat generation rate can induce local boiling regimes at the fuel rod surface in the hottest channels of the core, which can strongly modify the chemical environment of the cladding and influence the oxidation rate of zirconium alloys. Tests performed in out-of-pile loops under severe chemical and thermal-hydraulic conditions (nucleate boiling, higher lithium contents compared to PWRs) reveal two important phenomena: an increase of the oxidation rate of Zircaloy-4 cladding materials in 'high' lithiated environments; an enrichment of the chemical additives in the primary water (boron, lithium) at the surface of the cladding under nucleate boiling conditions. The latter phenomenon, also called 'hideout effect', is mainly controlled by some thermal hydraulic parameters such as bubble diameters and nucleation site density. These parameters strongly depend on the oxide morphology (roughness, porosity). The lack of reliable data in high temperature water environments has led to the development of a specific instrumentation based on visualization. The fitting of windows on the REGGAE out-of-pile loop provides an optical access to the two-phase flow regime under PWR operating conditions, allowing for the characterization of the parameters at the origin of the chemical species hideout process. These direct observations of the cladding surfaces subjected to nucleate boiling conditions provide information about the development of the boiling mechanisms in relation to the morphology of the oxide layers (porosity, thickness, roughness). (author)

  11. Coupled effects of the precipitation of secondary species on the mechanical behaviour and chemical degradation of concretes

    International Nuclear Information System (INIS)

    Planel, D.

    2002-06-01

    Sulfate attack of cement-based materials remains an important problem for the durability assessment of containers and disposal engineering barriers dedicated to the long-term storage of radioactive wastes since underground water which may reach these elements contains small quantities of sulfates (7-31 mmol/1). This work contributes to the study of sulfate-induced damage mechanisms, to their understanding and modelling. The experimental phases of this study aimed at the understanding of the different physico-chemical phenomena involved during an external sulfate attack at following their evolution and their impact on the transport and mechanical properties of the material. Leaching experiments in pure water and in a solution of sodium sulfate (with a sulfate content of 15 mmol/1), have been performed simultaneously on OPC paste (w/c 0,4)in order to allow a comparison of test results. The frequent analysis of the leachant has shown a consumption of sulfate ions by the matrix, proportional to the square rate of time. The use of X-Ray Diffraction on powders, obtained by scraping the calcium-depleted part of the samples, led a precise view of the cement paste mineralogy, during sulfate attack. The use of Scanning Electron Microscopy (SEM) and Energy Dispersive Spectrometer (EDS) confirmed the correctness of XRD profiles and brought important informations concerning cracking distribution and localisation. In addition, a visual monitoring of crack appearance and evolution completed the previous observations. Based on these experimental results, a simplified model accounting for the chemical degradation of cement paste in sulfated water has been proposed. A geochemical code, coupling the chemistry in solution with the reactive transport in porous media has been used for this purpose. The model accounts for the evolution of transport properties (diffusivity) associated with the calcium-depleting of the cement matrix and the precipitation of secondary phases (gypsum

  12. Elucidating Direct Photolysis Mechanisms of Different Dissociation Species of Norfloxacin in Water and Mg2+ Effects by Quantum Chemical Calculations.

    Science.gov (United States)

    Wang, Se; Wang, Zhuang

    2017-11-11

    The study of pollution due to combined antibiotics and metals is urgently needed. Photochemical processes are an important transformation pathway for antibiotics in the environment. The mechanisms underlying the effects of metal-ion complexation on the aquatic photochemical transformation of antibiotics in different dissociation forms are crucial problems in science, and beg solutions. Herein, we investigated the mechanisms of direct photolysis of norfloxacin (NOR) in different dissociation forms in water and metal ion Mg 2+ effects using quantum chemical calculations. Results show that different dissociation forms of NOR had different maximum electronic absorbance wavelengths (NOR 2+ direct photolysis pathways were de-ethylation (N7-C8 bond cleavage) and decarboxylation (C2-C5 bond cleavage). Furthermore, the presence of Mg 2+ changed the order of the wavelength at maximum electronic absorbance (NOR⁺-Mg 2+ direct photolysis of NOR⁰, NOR⁺, and NOR 2+ . The calculated TS results indicated that the presence of Mg 2+ increased E a for most direct photolysis pathways of NOR, while it decreased E a for some direct photolysis pathways such as the loss of the piperazine ring and the damage of the piperazine ring of NOR⁰ and the defluorination of NOR⁺.

  13. A detailed study on chemical characterization of essential oil components of two Plectranthus species grown in Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Merajuddin Khan

    2016-11-01

    Full Text Available The chemical composition of the essential oils of Plectranthus cylindraceus and Plectranthus arabicus grown in Saudi Arabia were analyzed using gas chromatography techniques (GC–MS, GC–FID, Co-GC, LRI determination, and database and literature searches using two different stationary phase columns (polar and nonpolar. The analysis led to the characterization of a total of 157 different compounds from both oils. In the oil derived from P. cylindraceus, 79 compounds were identified, whereas 132 compounds were identified in the oil derived from P. arabicus; these compounds account for 95.2% and 98.4% of the total oil compositions, respectively. The major constituents of P. cylindraceus oil were patchouli alcohol (55.5 ± 0.01%, 1,8-cineole (6.0 ± 0.01% and valerianol (3.8 ± 0.18%, whereas, the main compounds of the P. arabicus oil were 1,8-cineole (50.5 ± 1.37%, β-pinene (7.0 ± 0.08%, camphor (6.3 ± 0.19% and β-myrcene (4.1 ± 0.10%. To the best of our knowledge, patchouli alcohol found in high concentration in the P. cylindraceus oil has never been reported from the genus Plectranthus. Moreover, this is the first phytochemical study of P. arabicus.

  14. A numerical analysis for non-linear radiation in MHD flow around a cylindrical surface with chemically reactive species

    Directory of Open Access Journals (Sweden)

    Junaid Ahmad Khan

    2018-03-01

    Full Text Available Boundary layer flow around a stretchable rough cylinder is modeled by taking into account boundary slip and transverse magnetic field effects. The main concern is to resolve heat/mass transfer problem considering non-linear radiative heat transfer and temperature/concentration jump aspects. Using conventional similarity approach, the equations of motion and heat transfer are converted into a boundary value problem whose solution is computed by shooting method for broad range of slip coefficients. The proposed numerical scheme appears to improve as the strengths of magnetic field and slip coefficients are enhanced. Axial velocity and temperature are considerably influenced by a parameter M which is inversely proportional to the radius of cylinder. A significant change in temperature profile is depicted for growing wall to ambient temperature ratio. Relevant physical quantities such as wall shear stress, local Nusselt number and local Sherwood number are elucidated in detail. Keywords: Stretchable boundary, Thermal radiation, Chemical reaction, Mathematical modeling, Non-linear differential system, Mass transfer

  15. Chemical composition and antimicrobial activity of the essential oils of some species of Anthemis sect. Anthemis (Asteraceae) from Sicily.

    Science.gov (United States)

    Riccobono, Luana; Maggio, Antonella; Bruno, Maurizio; Spadaro, Vivienne; Raimondo, Francesco Maria

    2017-12-01

    The chemical composition of the essential oils isolated from the aerial parts of Anthemis arvensis L. subsp. arvensis, Anthemis cretica subsp. messanensis (Brullo) Giardina & Raimondo and from flowers and leaves of Anthemis cretica subsp. columnae (Ten.) Frezén were determinated by GC-FID and GC-MS analyses. Torreyol (85.4%) was recognised as the main constituent of the Anthemis arvensis subsp. arvensis essential oil, while in the essential oils of Anthemis cretica subsp. messanensis, collected on the rock and cultivated in Hortus Botanicus Panormitanus, (E)-chrysanthenyl acetate (28.8 and 24.2% resp.), 14-hydroxy-α-humulene (8.1 and 5.3% resp.), santolina triene (8 and 5.8% resp.) and α-pinene (6.7 and 5.4% resp.) prevailed. 18-cineole (13.3 and 12.2% resp.), was the main component of both flower and leaf oils of Anthemis cretica subsp. columnae together with δ-cadinene (9.0 and 8.2% resp.) and (E)-caryophyllene (8.3 and 5.6% resp.).

  16. Evaluation of Physico-Chemical and Fungal Species Associated with Oil Contaminated Soil from Selected Automobile Garage in Sokoto Metropolis

    Directory of Open Access Journals (Sweden)

    Hassan Muhammad Maishanu

    2018-03-01

    Full Text Available This study was conducted with a view to evaluating the physicochemical and mycological properties of different oil contaminated soils collected from three different automobile garages in Sokoto Metropolis, and uncontaminated soil from the temporary site, Usmanu Danfodiyo University, Sokoto (UDUS was used as the control. The pH was determined using pH meter model Hanna (H1991301, quantity of mineral elements was evaluated in accordance with Murphy and Fungi were isolated from the three oil contaminated samples (A, B. and C and the uncontaminated (sample D as control, this was done by standard procedure using the method of P. Ren, T. Jankun & B. Leaderer. The physical, chemical, and mineral elements from the oil-contaminated soils of the three automobile garages and control. The results of particle soil analysis revealed the high content of sandy soil (96.2 to 87.3 and silt is the lowest with (2.5–0.6. Magnesium had the highest concentration of studied minerals, ranging from 193 to 649.2 mg/kg. while PH result revealed that the soil samples were pH value ranged from (16.85–16.20 in oil Contaminated samples, while the control had 15.90, and electrical conductivity ranged from 12.8–13.8 % and 28 % in control, four fungal isolates Aspergillus sp., Penicillum sp., Mucor sp. and Sporobolomyces sp. were identified based on colonial, sexual and morphological characteristics. These fungal strains can be used in bioremediation process and oil pollution reduction in aquatic ecosystems.

  17. Transport behavior of surrogate biological warfare agents in a simulated landfill: Effect of leachate recirculation and water infiltration

    KAUST Repository

    Saikaly, Pascal

    2010-11-15

    An understanding of the transport behavior of biological warfare (BW) agents in landfills is required to evaluate the suitability of landfills for the disposal of building decontamination residue (BDR) following a bioterrorist attack on a building. Surrogate BW agents, Bacillus atrophaeus spores and Serratia marcescens, were spiked into simulated landfill reactors that were filled with synthetic building debris (SBD) and operated for 4 months with leachate recirculation or water infiltration. Quantitative polymerase chain reaction (Q-PCR) was used to monitor surrogate transport. In the leachate recirculation reactors, <10% of spiked surrogates were eluted in leachate over 4 months. In contrast, 45% and 31% of spiked S. marcescens and B. atrophaeus spores were eluted in leachate in the water infiltration reactors. At the termination of the experiment, the number of retained cells and spores in SBD was measured over the depth of the reactor. Less than 3% of the total spiked S. marcescens cells and no B. atrophaeus spores were detected in SBD. These results suggest that significant fractions of the spiked surrogates were strongly attached to SBD. © 2010 American Chemical Society.

  18. Transport behavior of surrogate biological warfare agents in a simulated landfill: Effect of leachate recirculation and water infiltration

    KAUST Repository

    Saikaly, Pascal; Hicks, Kristin A.; Barlaz, Morton A.; De Los Reyes, Francis Delos De Los

    2010-01-01

    An understanding of the transport behavior of biological warfare (BW) agents in landfills is required to evaluate the suitability of landfills for the disposal of building decontamination residue (BDR) following a bioterrorist attack on a building. Surrogate BW agents, Bacillus atrophaeus spores and Serratia marcescens, were spiked into simulated landfill reactors that were filled with synthetic building debris (SBD) and operated for 4 months with leachate recirculation or water infiltration. Quantitative polymerase chain reaction (Q-PCR) was used to monitor surrogate transport. In the leachate recirculation reactors, <10% of spiked surrogates were eluted in leachate over 4 months. In contrast, 45% and 31% of spiked S. marcescens and B. atrophaeus spores were eluted in leachate in the water infiltration reactors. At the termination of the experiment, the number of retained cells and spores in SBD was measured over the depth of the reactor. Less than 3% of the total spiked S. marcescens cells and no B. atrophaeus spores were detected in SBD. These results suggest that significant fractions of the spiked surrogates were strongly attached to SBD. © 2010 American Chemical Society.

  19. Chemical composition, toxicity and antioxidant activities of essential oils of stem bark of Nigerian species of guava (Psidium guajava Linn.)

    Science.gov (United States)

    Fasola, Taiye R.; Oloyede, Ganiyat Kehinde; Aponjolosun, Babalola S.

    2011-01-01

    Essential oil from the stem bark of Nigerian species of Psidium guajava of the family Myrtaceae was obtained by hydro-distillation using an all-glass Clavenger apparatus. GC and GC/MS analysis were carried out on the essential oil and was found to contain 62 compounds constituting 99.98 % of the total oil composition. The principal constituents are hydrocarbons, amines, amides and esters with 3,6-dioxa-2,4,5,7-tetraoctane,2,2,4,4,5,5,7,7-octamethyl (11.67 %) and cyclononane (10.66 %) dominating the total essential oil. Brine shrimp lethality test was carried out to determin