130,419 research outputs found
Computational analysis of internal and external EGR strategies combined with Miller cycle concept for a two stage turbocharged medium speed marine Diesel engine
No full textCombining dual stage turbocharging with extreme Miller timings to achieve NOx emissions reductions in marine Diesel engines
No full textDegradation of trans.ferulic and p-coumaric acid by Acinetobacter calcoaceticus DSM 586
No full textCell suspensions of Acinetobacter calcoaceticus strain DSM 586 and DSM 590 were able to grow on benzoic, p-hydroxybenzoic and vanillic acid as sole carbon source. Testing the utilization of trans-ferulic and p-coumaric acid, we found that the sole A. calcoaceticus DSM 586 efficiently degraded the lignocellulose related monomers. Cells induced with trans-ferulic acid were able to oxidize trans-ferulic, p-coumaric, vanillic, p-hydroxybenzoic and protocatechuic acid at rates higher than the uninduced culture. The same activity was found in the p-coumaric acid induced culture. Two aromatic compounds, vanillic and p-hydroxybenzoic acid, were isolated from culture filtrates of trans-ferulic and p-coumaric acid grown cells, respectively, and further characterized by high performance liquid chromatography, 1H- and 13C-nuclear magnetic resonance and ultraviolet spectrophotometry. Cell extracts of trans-ferulic or p-coumaric acid induced cultures were shown to rapidly convert protocatechuic acid to β-carboxymuconic acid. Moreover, A. calcoaceticus DSM 586 produced high levels of protocatechuic 3,4-dioxygenase compared to cathecol 1,2-dioxygenase and gentisate 1,2-dioxygenase in the degradation of trans-ferulic or p-coumaric acid. Based upon these results, a reaction sequence for the complete degradation of trans-ferulic and p-coumaric acid in A. calcoaceticus DSM 586 is proposed. © 1995
A DOE Analysis of Compression Ratio, Injection Timing, Injector Nozzle Hole Size and Number on Performance and Emissions in a Diesel Marine Engine
No full textMeSH term explosion and author rank improve expert recommendations
Full text linkInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Osteoblastic cell secretome: A novel role for progranulin during risedronate treatment
No full textIt is well established that osteoblasts, the key cells involved in bone formation during development and in adult life, secrete a number of glycoproteins harboring autocrine and paracrine functions. Thus, investigating the osteoblastic secretome could yield important information for the pathophysiology of bone. In the present study, we characterized for the first time the secretome of human Hobit osteoblastic cells. We discovered that the secretome comprised 89 protein species including the powerful growth factor progranulin. Recombinant human progranulin (6nM) induced phosphorylation of mitogen-activated protein kinase in both Hobit and osteocytic cells and induced cell proliferation and survival. Notably, risedronate, a nitrogen-containing bisphosphonate widely used in the treatment of osteoporosis, induced the expression and secretion of progranulin in the Hobit secretome. In addition, our proteomic study of the Hobit secretome revealed that risedronate induced the expression of ERp57, HSP60 and HSC70, three proteins already shown to be associated with the prevention of bone loss in osteoporosis. Collectively, our findings unveil novel targets of risedronate-evoked biological effects on osteoblast-like cells and further our understanding of the mechanisms of action of this currently used compound
Effect of Hanseniaspora vineae and Saccharomyces cerevisiae co-fermentations on aroma compound production in beer
Full text linkIn recent years, the boom of the craft beer industry refocused the biotech interest from ethanol production to diversification of beer aroma profiles. This study analyses the fermentative phenotype of a collection of non-conventional yeasts and examines their role in creating new flavours, particularly through co-fermentation with industrial Saccharomyces cerevisiae. High-throughput solid and liquid media fitness screening compared the ability of eight Saccharomyces and four non-Saccharomyces yeast strains to grow in wort. We determined the volatile profile of these yeast strains and found that Hanseniaspora vineae displayed a particularly high production of the desirable aroma compounds ethyl acetate and 2-phenethyl acetate. Given that H. vineae on its own can't ferment maltose and maltotriose, we carried out mixed wort co-fermentations with a S. cerevisiae brewing strain at different ratios. The two yeast strains were able to co-exist throughout the experiment, regardless of their initial inoculum, and the increase in the production of the esters observed in the H. vineae monoculture was maintained, alongside with a high ethanol production. Moreover, different inoculum ratios yielded different aroma profiles: the 50/50 S. cerevisiae/H. vineae ratio produced a more balanced profile, while the 10/90 ratio generated stronger floral aromas. Our findings show the potential of using different yeasts and different inoculum combinations to tailor the final aroma, thus offering new possibilities for a broader range of beer flavours and style
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
Full text linkBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
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