139 research outputs found
Effect of Treatment and Cultivar on the Ensiling of Corn Stover
Nine cultivars of corn stover selected for ethanol potential were harvested (34 to 40% dry matter) and each ensiled with six treatments: untreated, lactic acid bacteria, cell-wall degrading enzymes, sulfuric acid, bacteria-enzyme combination and enzyme-acid combination. Ensiling was carried out in vacuum-sealed bags at ~22°C for 60 d. The untreated stovers ensiled well. Lactic acid bacteria and enzyme treatments had no effect on pH, but the bacteria-enzyme combination lowered pH in some cultivars. The acid and acid-enzyme treatments had low pH values ranging from 1.3 to 1.5. Lactic acid was generally highest in the bacteria-enzyme treatment whereas acetic acid was highest for the acid treatments. The acid treatments substantially reduced hemicellulose. Potential ethanol yield on average was highest in the bacteria-enzyme treatments
The ethics of using transgenic non-human primates to study what makes us human
An ongoing flood of comparative genomic data is identifying human lineage specific (HLS) sequences of unknown function, and there is strong interest in investigating their functional effects. Transgenic apes, our closest evolutionary relative, have the highest potential to express HLS sequences as they are expressed in Homo sapiens and likewise experience harm from such transgenic research. These harms render the conduct of this research ethically unacceptable in apes, justifying regulatory barriers between these species and all other non-human primates for transgenic research
Combined and single effects of pesticide carbaryl and toxic Microcystis aeruginosa on the life history of Daphnia pulicaria
The combined influence of a pesticide (carbaryl) and a cyanotoxin (microcystin LR) on the life history of Daphnia pulicaria was investigated. At the beginning of the experiments animals were pulse exposed to carbaryl for 24 h and microcystins were delivered bound in Microcystis’ cells at different, sub-lethal concentrations (chronic exposure). In order to determine the actual carbaryl concentrations in the water LC–MS/MS was used. For analyses of the cyanotoxin concentration in Daphnia’s body enzyme-linked immunosorbent assay (ELISA) was used. Individual daphnids were cultured in a flow-through system under constant light (16 h of light: 8 h of dark), temperature (20°C), and food conditions (Scenedesmus obliquus, 1 mg of C l−1). The results showed that in the treatments with carbaryl egg numbers per female did not differ significantly from controls, but the mortality of newborns increased significantly. Increasing microcystin concentrations significantly delayed maturation, reduced size at first reproduction, number of eggs, and newborns. The interaction between carbaryl and Microcystis was highly significant. Animals matured later and at a smaller size than in controls. The number of eggs per female was reduced as well. Moreover, combined stressors caused frequent premature delivery of offspring with body deformations such as dented carapax or an undeveloped heart. This effect is concluded to be synergistic and could not be predicted from the effects of the single stressors.
Avaliação de híbridos de milho obtidos do cruzamento entre linhagens com diferentes níveis de degradabilidade da matéria seca
Thermo-electrochemical production of compressed hydrogen from methane with near-zero energy loss
[EN] Conventional production of hydrogen requires large industrial plants to minimize energy losses and capital costs associated with steam reforming, water-gas shift, product separation and compression. Here we present a protonic membrane reformer (PMR) that produces high-purity hydrogen from steam methane reforming in a single-stage process with near-zero energy loss. We use a BaZrO3-based proton-conducting electrolyte deposited as a dense film on a porous Ni composite electrode with dual function as a reforming catalyst. At 800 degrees C, we achieve full methane conversion by removing 99% of the formed hydrogen, which is simultaneously compressed electrochemically up to 50 bar. A thermally balanced operation regime is achieved by coupling several thermo-chemical processes. Modelling of a small-scale (10 kg H-2 day-1) hydrogen plant reveals an overall energy efficiency of >87%. The results suggest that future declining electricity prices could make PMRs a competitive alternative for industrial-scale hydrogen plants integrating CO2 capture.This work was supported by the Research Council of Norway (grant 256264) and the Spanish Government (SEV-2016-0683 grant).Malerød-Fjeld, H.; Clark, D.; Yuste Tirados, I.; Zanón González, R.; Catalán-Martínez, D.; Beeaff, D.; Hernández Morejudo, S.... (2017). Thermo-electrochemical production of compressed hydrogen from methane with near-zero energy loss. Nature Energy. 2(12):923-931. https://doi.org/10.1038/s41560-017-0029-4S923931212Morejudo, S. H. et al. Direct conversion of methane to aromatics in a catalytic co-ionic membrane reactor. Science 353, 563–566 (2016).Chu, S. & Majumdar, A. Opportunities and challenges for a sustainable energy future. Nature 488, 294–303 (2012).Logan, B. E. & Elimelech, M. Membrane-based processes for sustainable power generation using water. Nature 488, 313–319 (2012).Rostrup-Nielsen, J. R. Catalysis and large-scale conversion of natural gas. Catal. Today 21, 257–267 (1994).Voss, C. Applications of pressure swing adsorption technology. Adsorption 11, 527–529 (2005).Gallucci, F., Fernandez, E., Corengia, P. & van Sint Annaland, M. Recent advances on membranes and membrane reactors for hydrogen production. Chem. Eng. Sci. 92, 40–66 (2013).Boeltken, T., Wunsch, A., Gietzelt, T., Pfeifer, P. & Dittmeyer, R. Ultra-compact microstructured methane steam reformer with integrated Palladium membrane for on-site production of pure hydrogen: Experimental demonstration. Int. J. Hydrogen Energy 39, 18058–18068 (2014).Al-Mufachi, N. A., Rees, N. V. & Steinberger-Wilkens, R. Hydrogen selective membranes: A review of palladium-based dense metal membranes. Renew. Sustainable Energy Rev. 47, 540–551 (2015).Sengodan, S. et al. Layered oxygen-deficient double perovskite as an efficient and stable anode for direct hydrocarbon solid oxide fuel cells. Nat. Mater. 14, 205–209 (2015).Myung, J.-h, Neagu, D., Miller, D. N. & Irvine, J. T. S. Switching on electrocatalytic activity in solid oxide cells. Nature 537, 528–531 (2016).Iwahara, H., Uchida, H., Ono, K. & Ogaki, K. Proton conduction in sintered oxides based on BaCeO3. J. Electrochem. Soc. 135, 529–533 (1988).Hamakawa, S., Hibino, T. & Iwahara, H. Electrochemical methane coupling using proton conductors. J. Electrochem. Soc. 140, 459–462 (1993).Bonanos, N., Knight, K. S. & Ellis, B. Perovskite solid electrolytes: structure, transport properties and fuel cell applications. Solid State Ion. 79, 161–170 (1995).Norby, T. Solid-state protonic conductors: principles, properties, progress and prospects. Solid State Ion. 125, 1–11 (1999).Kreuer, K. D. On the development of proton conducting materials for technological applications. Solid State Ion. 97, 1–15 (1997).Kreuer, K. D. Aspects of the formation and mobility of protonic charge carriers and the stability of perovskite-type oxides. Solid State Ion. 125, 285–302 (1999).Kreuer, K. D. Proton-conducting oxides. Annu. Rev. Mater. Res. 33, 333–359 (2003).Tao, S. W. & Irvine, J. T. S. A stable, easily sintered proton-conducting oxide electrolyte for moderate-temperature fuel cells and electrolyzers. Adv. Mater. 18, 11581-1584 (2006).Wang, H., Peng, R., Wu, X., Hu, J. & Xia, C. Sintering behavior and conductivity study of yttrium-doped BaCeO3–BaZrO3 solid solutions using ZnO additives. J. Am. Ceram. Soc. 92, 2623–2629 (2009).Coors, W. G. in Advances in Ceramics—Synthesis and Characterization, Processing and Specific Applications (Ed. Sikalidis, C.) Ch. 22, 501–520 (InTech, UK, 2011) (2011).Manabe, R. et al. Surface protonics promotes catalysis. Sci. Rep. 6, 38007, (2016).Rohland, B., Eberle, K., Ströbel, R., Scholta, J. & Garche, J. Electrochemical hydrogen compressor. Electrochimica Acta 43, 3841–3846 (1998).Kochetova, N., Animitsa, I., Medvedev, D., Demin, A. & Tsiakaras, P. Recent activity in the development of proton-conducting oxides for high-temperature applications. RSC Adv. 6, 73222–73268 (2016).Yamazaki, Y. et al. Proton trapping in yttrium-doped barium zirconate. Nat. Mater. 12, 647–651 (2013).Kjølseth, C. et al. Space-charge theory applied to the grain boundary impedance of proton conducting BaZr0.9Y0.1O3-δ . Solid State Ion. 181, 268–275 (2010).Coors, W. G A stoichiometric titration method for measuring galvanic hydrogen flux in ceramic hydrogen separation membranes. J. Membr. Sci. 458, 245–253 (2014).Zeppieri, M., Villa, P. L., Verdone, N., Scarsella, M. & De Filippis, P. Kinetic of methane steam reforming reaction over nickel- and rhodium-based catalysts. Appl. Catal. A 387, 147–154 (2010).Wang, B., Zhu, J. & Lin, Z. A theoretical framework for multiphysics modeling of methane fueled solid oxide fuel cell and analysis of low steam methane reforming kinetics. Appl. Energy 176, 1–11 (2016).Overview of Electricity Production and Use in Europe (European Environment Agency, 2016).Edwards, R., Larive, J.-F., Rickeard, D. & Weindorf, W. Well-To-Wheels Analysis of Future Automotive Fuels and Powertrains in the European Context, Well-to-Tank Report Version 4.a, JEC Well-to-Wheels Analysis (Joint Research Centre, 2014).Cho, V. H., Hamilton, B. A. & Kuehn, N. J. Assessment of Hydrogen Production with CO 2 Capture Volume 1: Baseline State-of-the-Art Plants (National Energy Technology Laboratory, 2010).Schjølberg, I. et al. Small-Scale Reformers for On-Site Hydrogen Supply (International Energy Agency-Hydrogen Implementing Agreement, 2012).de Visser, E. et al. Dynamis CO2 quality recommendations. Int. J. Greenhouse Gas Control 2, 478–484 (2008).Bertucciolo, L. et al. Development of Water Electrolysis in the European Union (Fuel Cells and Hydrogen Joint Undertaking, 2014).Edwards, R. et al. Well-To-Wheels Analysis of Future Automotive Fuels and Powertrains in the European Context, Well-to-Wheels Report Version 4.a, JEC Well-to-Wheels Analysis (Joint Research Centre 2014).Huss, A., Maas, H. & Hass, H. Well-to-Wheels Analysis of Future Automotive Fuels and Powertrains in the European Context, Tank-to-Wheels Report Version 4.0, JEC Technical Reports (Joint Research Centre, 2013)
Parasite-insecticide interactions: a case study of Nosema ceranae and fipronil synergy on honeybee
In ecosystems, a variety of biological, chemical and physical stressors may act in combination to induce illness in populations of living organisms. While recent surveys reported that parasite-insecticide interactions can synergistically and negatively affect honeybee survival, the importance of sequence in exposure to stressors has hardly received any attention. In this work, Western honeybees (Apis mellifera) were sequentially or simultaneously infected by the microsporidian parasite Nosema ceranae and chronically exposed to a sublethal dose of the insecticide fipronil, respectively chosen as biological and chemical stressors. Interestingly, every combination tested led to a synergistic effect on honeybee survival, with the most significant impacts when stressors were applied at the emergence of honeybees. Our study presents significant outcomes on beekeeping management but also points out the potential risks incurred by any living organism frequently exposed to both pathogens and insecticides in their habitat
Identification of Circulating Proteins associated With General Cognitive Function among Middle-Aged and Older adults
Identifying circulating proteins associated with cognitive function may point to biomarkers and molecular process of cognitive impairment. Few studies have investigated the association between circulating proteins and cognitive function. We identify 246 protein measures quantified by the SomaScan assay as associated with cognitive function (p \u3c 4.9E-5, n up to 7289). Of these, 45 were replicated using SomaScan data, and three were replicated using Olink data at Bonferroni-corrected significance. Enrichment analysis linked the proteins associated with general cognitive function to cell signaling pathways and synapse architecture. Mendelian randomization analysis implicated higher levels of NECTIN2, a protein mediating viral entry into neuronal cells, with higher Alzheimer\u27s disease (AD) risk (p = 2.5E-26). Levels of 14 other protein measures were implicated as consequences of AD susceptibility (p \u3c 2.0E-4). Proteins implicated as causes or consequences of AD susceptibility may provide new insight into the potential relationship between immunity and AD susceptibility as well as potential therapeutic targets
Demographic responses of Daphnia magna fed transgenic Bt-maize
The food/feed quality of a variety of genetically modified (GM) maize expressing Cry1Ab Bt-toxin was tested over the life-cycle of Daphnia magna, an arthropod commonly used as model organism in ecotoxicological studies. Demographic responses were compared between animals fed GM or unmodified (UM) near isogenic maize, with and without the addition of predator smell. Age-specific data on survival and birth rates were integrated and analysed using life tables and Leslie matrices. Survival, fecundity and population growth rate (PGR) data generally disfavoured transgenic Bt-maize as feed for D. magna compared to animals fed the unmodified (UM) near isogenic line of maize. Decomposition of age-specific effects revealed that the most important contributions to a reduced PGR in the GM-fed group came from both fecundity and survival differences early in life. We conclude that juvenile and young adult stages are the most sensitive experimental units and should be prioritized in future research. These stages are often omitted in toxicological/ecotoxicological studies and in feeding trials
Identification of circulating proteins associated with general cognitive function among middle-aged and older adults
Identifying circulating proteins associated with cognitive function may point to biomarkers and molecular process of cognitive impairment. Few studies have investigated the association between circulating proteins and cognitive function. We identify 246 protein measures quantified by the SomaScan assay as associated with cognitive function (p < 4.9E-5, n up to 7289). Of these, 45 were replicated using SomaScan data, and three were replicated using Olink data at Bonferroni-corrected significance. Enrichment analysis linked the proteins associated with general cognitive function to cell signaling pathways and synapse architecture. Mendelian randomization analysis implicated higher levels of NECTIN2, a protein mediating viral entry into neuronal cells, with higher Alzheimer’s disease (AD) risk (p = 2.5E-26). Levels of 14 other protein measures were implicated as consequences of AD susceptibility (p < 2.0E-4). Proteins implicated as causes or consequences of AD susceptibility may provide new insight into the potential relationship between immunity and AD susceptibility as well as potential therapeutic targets
In situ degradability of corn stover and elephant-grass harvested at four stages of maturity
Among tropical forages, corn silage is largely used by farmers trying to explore the maximum genetic potential from the animals. However, other tropical forages, such as elephant-grass (Pennisetum purpureum), are more productive and therefore cheaper to use than corn silage. Our objective was to compare the in situ degradability of elephant-grass with that from corn hybrids, all harvested at four stages of maturity. The experimental design followed a randomized block design with nested subplots. Two corn hybrids: AG5011, ZN8392 were harvested with 25, 30, 35, and 40% dry matter (DM) in the whole plant, and separated in stem + leaf sheath + leaf blade (stover), and cobs. Elephant-grass was harvested with 30, 40, 50 and 60 days after a leveling cut. Dried and ground samples were incubated in nylon bags inside the rumen for 0, 6, 12, 24, 48 and 72 h to estimate the kinetics of ruminal DM and neutral detergent fiber (NDF) degradation. The advance of maturity increased the NDF and acid detergent fiber (ADF) content in elephant-grass, and reduced its DM degradability. However, maturity had little or no effect on fiber content and DM degradability of corn stover. Elephant-grass had a higher NDF degradability than corn stover, and there was no effect of maturity on NDF degradability of either elephant-grass or corn stover. Fiber degradability of elephant-grass was not worse than that of corn stover, and therefore the choice of forage should be made on economical analysis rather than assuming an intrinsic low production potential for elephant-grass based diets.Dentre as forragens, a silagem de milho é amplamente utilizada pelos fazendeiros que visam explorar o máximo do potencial genético dos animais. No entanto, outros volumosos tropicais como o capim-elefante (Pennisetum purpureum) são mais produtivos e, portanto, mais baratos do que a silagem de milho. Nosso objetivo foi comparar a degradabilidade in situ do capim-elefante com a degradabilidade de híbridos de milho, colhidos em quatro estágios de maturidade. O experimento seguiu um delineamento de blocos ao acaso com sub-parcelas. Dois híbridos de milho: AG5011 e ZN8392 foram colhidos com 25, 30, 35 e 40% matéria seca (MS) na planta toda e separados na fração colmo + bainha + folhas e espigas. Capim elefante foi colhido 30, 40, 50 e 60 dias após o corte de nivelamento. As amostras secas e trituradas foram incubadas no rúmen por 0, 6, 12, 24, 48 e 72 h para cálculo da cinética da degradação ruminal da MS e da fibra em detergente neutro (FDN). O avanço da maturidade aumentou os teores de FDN e fibra em detergente ácido (FDA) do capim elefante e reduziu a degradabilidade da MS. Entretanto, a maturidade teve pouco efeito sobre os teores de fibra e a degradabilidade da MS da fração planta dos híbridos de milho. O capim elefante apresentou maior degradabilidade da FDN do que híbridos de milho, e não houve efeito da maturidade sobre a degradabilidade da FDN das duas espécies. A degradabilidade da fibra de capim-elefante não é pior do que a de híbridos de milho e, portanto a escolha da forragem deve ser feita com base em análises econômicas ao invés de assumir um menor potencial de produção em dietas a base de capim elefante
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