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  • 1
    Publikationsdatum: 2017-04-01
    Beschreibung: A precision measurement of jet cross sections in neutral current deep-inelastic scattering for photon virtualities $$5.5
    Print ISSN: 1434-6044
    Digitale ISSN: 1434-6052
    Thema: Physik
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  • 2
    Publikationsdatum: 2017-11-01
    Beschreibung: The strong coupling constant $$alpha _mathrm{s}$$ α s is determined from inclusive jet and dijet cross sections in neutral-current deep-inelastic ep scattering (DIS) measured at HERA by the H1 collaboration using next-to-next-to-leading order (NNLO) QCD predictions. The dependence of the NNLO predictions and of the resulting value of $$alpha _mathrm{s} (m_mathrm{Z})$$ α s ( m Z ) at the Z-boson mass $$m_Z$$ m Z are studied as a function of the choice of the renormalisation and factorisation scales. Using inclusive jet and dijet data together, the strong coupling constant is determined to be $$alpha _mathrm{s} (m_mathrm{Z}) =0.1157,(20)_mathrm{exp},(29)_mathrm{th}$$ α s ( m Z ) = 0.1157 ( 20 ) exp ( 29 ) th . Complementary, $$alpha _mathrm{s} (m_mathrm{Z})$$ α s ( m Z ) is determined together with parton distribution functions of the proton (PDFs) from jet and inclusive DIS data measured by the H1 experiment. The value $$alpha _mathrm{s} (m_mathrm{Z}) =0.1142,(28)_mathrm{tot}$$ α s ( m Z ) = 0.1142 ( 28 ) tot obtained is consistent with the determination from jet data alone. The impact of the jet data on the PDFs is studied. The running of the strong coupling is tested at different values of the renormalisation scale and the results are found to be in agreement with expectations.
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    Thema: Physik
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  • 3
    Publikationsdatum: 2015-08-11
    Beschreibung: In this study, the influence of twenty different single (i.e. 19 amino acids and ammonium sulphate) and two multiple nitrogen sources (N-sources) on growth and fermentation (i.e. glucose consumption and ethanol production) performance of Saccharomyces cerevisiae and of four wine-related non- Saccharomyces yeast species ( Lachancea thermotolerans , Metschnikowia pulcherrima , Hanseniaspora uvarum and Torulaspora delbrueckii ) was investigated during alcoholic fermentation. Briefly, the N-sources with beneficial effects on all performance parameters (or for the majority of them) for each yeast species were alanine, arginine, asparagine, aspartic acid, glutamine, isoleucine, ammonium sulphate, serine, valine and mixtures of 19 amino acids and of 19 amino acids plus ammonium sulphate (for S. cerevisiae ), serine (for L. thermotolerans ), alanine (for H. uvarum ), alanine and asparagine (for M. pulcherrima ), arginine, asparagine, glutamine, isoleucine and mixture of 19 amino acids (for T. delbrueckii ). Furthermore, our results showed a clear positive effect of complex mixtures of N-sources on S. cerevisiae and on T. delbrueckii (although to a lesser extent) as to all performance parameters studied, whereas for L. thermotolerans , H. uvarum and M. pulcherrima , single amino acids affected growth and fermentation performance to the same extent as the mixtures. Moreover, we found groups of N-sources with similar effects on the growth and/or fermentation performance of two or more yeast species. Finally, the influences of N-sources observed for T. delbrueckii and H. uvarum resembled those of S. cerevisiae the most and the least, respectively. Overall, this work contributes to an improved understanding of how different N-sources affect growth, glucose consumption and ethanol production of wine-related yeast species under oxygen-limited conditions, which, in turn, may be used to, e.g. optimize growth and fermentation performance of the given yeast upon N-source supplementation during wine fermentations.
    Print ISSN: 0175-7598
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    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
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  • 4
    Publikationsdatum: 2015-08-11
    Beschreibung: Saccharopolyspora spinosa produces tetra-cyclic macrolide spinosyns, a group of highly efficient pesticidal agents. However, this species lacks efficient vectors for genetic manipulation. In this study, the circular plasmid pCM32 was newly isolated from Saccharopolyspora endophytica YIM 61095. The complete nucleotide sequence of pCM32 consists of 14,611 bp and is predicted to encode 17 open reading frames (ORFs). Interestingly, a putative int gene in pCM32 was predicted by homologous alignment to encode an integrase belonging to the tyrosine family of integrases/recombinases. Plasmid pCM238 containing this int locus derived from pCM32 could be transferred by conjugation from Escherichia coli into Sa. spinosa at a high frequency. Integration of pCM238 in the host chromosome was demonstrated as site-specific recombination (at the tRNA Ser gene) via a 56-bp core sequence within the attP / attB sites. Plasmid pCM265, a shuttle vector containing the int and attP sequences of pCM32, was constructed to introduce foreign genes into Sa. spinosa . The production of spinosad approximately doubled in Sa. spinosa NRRL18395 after introducing pCM265-derived plasmids carrying the genes for phosphofructokinase (PFK) or anthranilate synthase. These results indicate that plasmid pCM32 is an actinomycete integrative and conjugative element (AICE) and that its derived integrative vectors are useful for efficiently introducing foreign DNA into Sa. spinosa .
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  • 5
    Publikationsdatum: 2015-08-11
    Beschreibung: In this work, Nannochloropsis salina was cultivated in a continuous-flow flat-plate photobioreactor, working at different residence times and irradiations to study the effect of the specific light supply rate on biomass productivity and photosynthetic efficiency. Changes in residence times lead to different steady-state cell concentrations and specific growth rates. We observed that cultures at steady concentration were exposed to different values of light intensity per cell. This specific light supply rate was shown to affect the photosynthetic status of the cells, monitored by fluorescence measurements. High specific light supply rate can lead to saturation and photoinhibition phenomena if the biomass concentration is not optimized for the selected operating conditions. Energy balances were applied to quantify the biomass growth yield and maintenance requirements in N. salina cells.
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    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
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  • 6
    Publikationsdatum: 2015-08-12
    Beschreibung: An open reading frame CC1225 from the Caulobacter crescentus CB15 genome sequence belongs to the Gfo/Idh/MocA protein family and has 47 % amino acid sequence identity with the glucose-fructose oxidoreductase from Zymomonas mobilis ( Zm GFOR). We expressed the ORF CC1225 in the yeast Saccharomyces cerevisiae and used a yeast strain expressing the gene coding for Zm GFOR as a reference. Cell extracts of strains overexpressing CC1225 (renamed as Cc aaor ) showed some Zm GFOR type of activity, producing D-gluconate and D-sorbitol when a mixture of D-glucose and D-fructose was used as substrate. However, the activity in Cc aaor expressing strain was 〉100-fold lower compared to strains expressing Zm gfor . Interestingly, C. crescentus AAOR was clearly more efficient than the Zm GFOR in converting in vitro a single sugar substrate D-xylose (10 mM) to xylitol without an added cofactor, whereas this type of activity was very low with Zm GFOR. Furthermore, when cultured in the presence of D-xylose, the S. cerevisiae strain expressing Cc aaor produced nearly equal concentrations of D-xylonate and xylitol (12.5 g D-xylonate l −1 and 11.5 g D-xylitol l −1 from 26 g D-xylose l −1 ), whereas the control strain and strain expressing Zm gfor produced only D-xylitol (5 g l −1 ). Deletion of the gene encoding the major aldose reductase, Gre3p, did not affect xylitol production in the strain expressing Cc aaor , but decreased xylitol production in the strain expressing Zm gfor . In addition, expression of Cc aaor together with the D-xylonolactone lactonase encoding the gene xylC from C. crescentus slightly increased the final concentration and initial volumetric production rate of both D-xylonate and D-xylitol. These results suggest that C. crescentus AAOR is a novel type of oxidoreductase able to convert the single aldose substrate D-xylose to both its oxidized and reduced product.
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    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
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  • 7
    Publikationsdatum: 2015-08-12
    Beschreibung: We have previously shown that overexpression of the human tumor suppressor protein P53 causes cell death of the yeast Saccharomyces cerevisiae . P53 overproduction led to transcriptional downregulation of some yeast genes, such as the TRX1/2 thioredoxin system, which plays a key role in cell protection against various oxidative stresses induced by reactive oxygen species (ROS). In the present work, the impact of TRX2 overexpression on apoptosis mediated by p53 overexpression in yeast is investigated. In yeast cells expressing P53 under an inducible promoter together with TRX2 under a strong constitutive promoter, we showed that Tr2p overproduction reduced the apoptotic effect exerted by P53 and increased the viability of the P53-overproducing cells. Furthermore, measurements of ROS amounts by flow cytometry and fluorescence microscopy indicated that the TRX2 protein acted probably through its increased detoxifying activity on the P53-generated ROS. The steady-state level and activity of P53 were not affected by TRX2 overexpression, as shown by western blotting and functional analysis of separated alleles in yeast (FASAY), respectively. The growth inhibitory effect of P53 was partially reversed by the antioxidant N -acetylcysteine. Our data strengthen the idea that overexpression of a single gene ( trx2 ) decreases the p53 -mediated cell death by decreasing ROS accumulation.
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    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
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  • 8
    Publikationsdatum: 2015-08-12
    Beschreibung: The moving bed biofilm reactor-membrane bioreactor (MBBR-MBR) is a novel solution to conventional activated sludge processes and membrane bioreactors. In this study, a pure MBBR-MBR was studied. The pure MBBR-MBR mainly had attached biomass. The bioreactor operated with a hydraulic retention time (HRT) of 9.5 h. The kinetic parameters for heterotrophic and autotrophic biomasses, mainly nitrite-oxidizing bacteria (NOB), were evaluated. The analysis of the bacterial community structure of the ammonium-oxidizing bacteria (AOB), NOB, and denitrifying bacteria (DeNB) from the pure MBBR-MBR was carried out by means of pyrosequencing to detect and quantify the contribution of the nitrifying and denitrifying bacteria in the total bacterial community. The relative abundance of AOB, NOB, and DeNB were 5, 1, and 3 %, respectively, in the mixed liquor suspended solids (MLSS), and these percentages were 18, 5, and 2 %, respectively, in the biofilm density (BD) attached to carriers. The pure MBBR-MBR had a high efficiency of total nitrogen (TN) removal of 71.81 ± 16.04 %, which could reside in the different bacterial assemblages in the fixed biofilm on the carriers. In this regard, the kinetic parameters for autotrophic biomass had values of Y A  = 2.3465 mg O 2  mg N −1 , μ m, A  = 0.7169 h −1 , and K NH  = 2.0748 mg N L −1 .
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  • 9
    Publikationsdatum: 2015-08-12
    Beschreibung: Slow sand filtration (SSF) is an effective low-tech water treatment method for pathogen and particle removal. Yet despite its application for centuries, it has been uncertain to which extent pathogenic microbes are removed by mechanical filtration or due to ecological interactions such as grazing and competition for nutrients. In this study, we quantified the removal of bacterial faecal indicators, Escherichia coli and Enterococcus faecalis , from secondary effluent of a wastewater treatment plant and analysed the microbial community composition in compartments of laboratory model SSF columns. The columns were packed with different sand grain sizes and eliminated 1.6–2.3 log units of faecal indicators, which translated into effluents of bathing water quality according to the EU directive (〈500 colony forming units of E. coli per 100 ml) for columns with small grain size. Most of that removal occurred in the upper filter area, the Schmutzdecke . Within that same zone, total bacterial numbers increased however, thus suggesting a specific elimination of the faecal indicators. The analysis of the microbial communities also revealed that some taxa were removed more from the wastewater than others. These results accentuate the contribution of biological mechanisms to water purification in SSF.
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  • 10
    Publikationsdatum: 2015-08-12
    Beschreibung: Pseudoalteromonas is widespread in various marine environments, and most strains can affect invertebrate larval settlement and metamorphosis by forming biofilms. However, the impact and the molecular basis of population diversification occurring in Pseudoalteromonas biofilms are poorly understood. Here, we show that morphological diversification is prevalent in Pseudoalteromonas species during biofilm formation. Two types of genetic variants, wrinkled (frequency of 12 ± 5 %) and translucent (frequency of 5 ± 3 %), were found in Pseudoalteromonas lipolytica biofilms. The inducing activities of biofilms formed by the two variants on larval settlement and metamorphosis of the mussel Mytilus coruscus were significantly decreased, suggesting strong antifouling activities. Using whole-genome re-sequencing combined with genetic manipulation, two genes were identified to be responsible for the morphology alternations. A nonsense mutation in AT00 _ 08765 led to a wrinkled morphology due to the overproduction of cellulose, whereas a point mutation in AT00 _ 17125 led to a translucent morphology via a reduction in capsular polysaccharide production. Taken together, the results suggest that the microbial behavior on larval settlement and metamorphosis in marine environment could be affected by the self-generated variants generated during the formation of marine biofilms, thereby rendering potential application in biocontrol of marine biofouling.
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    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
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  • 11
    Publikationsdatum: 2015-08-13
    Beschreibung: This study used an artificial enrichment microbial consortium to examine the effects of different substrate conditions on microbial diversity, composition, and function (e.g., zinc leaching efficiency) through adding pyrite (SP group), chalcopyrite (SC group), or both (SPC group) in sphalerite bioleaching systems. 16S rRNA gene sequencing analysis showed that microbial community structures and compositions dramatically changed with additions of pyrite or chalcopyrite during the sphalerite bioleaching process. Shannon diversity index showed a significantly increase in the SP (1.460), SC (1.476), and SPC (1.341) groups compared with control (sphalerite group, 0.624) on day 30, meanwhile, zinc leaching efficiencies were enhanced by about 13.4, 2.9, and 13.2 %, respectively. Also, additions of pyrite or chalcopyrite could increase electric potential (ORP) and the concentrations of Fe 3+ and H + , which were the main factors shaping microbial community structures by Mantel test analysis. Linear regression analysis showed that ORP, Fe 3+ concentration, and pH were significantly correlated to zinc leaching efficiency and microbial diversity. In addition, we found that leaching efficiency showed a positive and significant relationship with microbial diversity. In conclusion, our results showed that the complicated substrates could significantly enhance microbial diversity and activity of function.
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  • 12
    Publikationsdatum: 2015-08-13
    Beschreibung: A metagenomic fosmid expression library established from environmental DNA (eDNA) from the shallow hot vent sediment sample collected from the Levante Bay, Vulcano Island (Aeolian archipelago) was established in Escherichia coli . Using activity-based screening assays, we have assessed 9600 fosmid clones corresponding to approximately 350 Mbp of the cloned eDNA, for the lipases/esterases/lactamases, haloalkane and haloacid dehalogenases, and glycoside hydrolases. Thirty-four positive fosmid clones were selected from the total of 120 positive hits and sequenced to yield ca. 1360 kbp of high-quality assemblies. Fosmid inserts were attributed to the members of ten bacterial phyla, including Proteobacteria , Bacteroidetes , Acidobateria , Firmicutes , Verrucomicrobia , Chloroflexi , Spirochaetes , Thermotogae , Armatimonadetes , and Planctomycetes . Of ca. 200 proteins with high biotechnological potential identified therein, we have characterized in detail three distinct α/β-hydrolases (LIPESV12_9, LIPESV12_24, LIPESV12_26) and one new α-arabinopyranosidase (GLV12_5). All LIPESV12 enzymes revealed distinct substrate specificities tested against 43 structurally diverse esters and 4 p -nitrophenol carboxyl esters. Of 16 different glycosides tested, the GLV12_5 hydrolysed only p -nitrophenol-α-( l )-arabinopyranose with a high specific activity of about 2.7 kU/mg protein. Most of the α/β-hydrolases were thermophilic and revealed a high tolerance to, and high activities in the presence of, numerous heavy metal ions. Among them, the LIPESV12_24 was the best temperature-adapted, retaining its activity after 40 min of incubation at 90 °C. Furthermore, enzymes were active in organic solvents (e.g., 〉30 % methanol). Both LIPESV12_24 and LIPESV12_26 had the GXSXG pentapeptides and the catalytic triads Ser-Asp-His typical to the representatives of carboxylesterases of EC 3.1.1.1.
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  • 13
    Publikationsdatum: 2015-08-13
    Beschreibung: Feruloyl or ferulic acid esterase (Fae, EC 3.1.1.73) catalyzes the hydrolysis of ester bonds between polysaccharides and phenolic acid compounds in xylan side chain. In this study, the thermostability of a type A feruloyl esterase (AuFaeA) from Aspergillus usamii was increased by iterative saturation mutagenesis (ISM). Two amino acids, Ser33 and Asn92, were selected for saturation mutagenesis according to the B-factors analyzed by B-FITTER software and ΔΔG values predicted by PoPMuSiC algorithm. After screening the saturation mutagenesis libraries constructed in Pichia pastoris , 15 promising variants were obtained. The best variant S33E/N92-4 (S33E/N92R) produced a T m value of 44.5 °C, the half-lives ( t 1/2 ) of 35 and 198 min at 55 and 50 °C, respectively, corresponding to a 4.7 °C, 2.33- and 3.96-fold improvement compared to the wild type. Additionally, the best S33 variant S33-6 (S33E) was thermostable at 50 °C with a t 1/2 of 82 min, which was 32 min longer than that of the wild type. All the screened S33E/N92 variants were more thermostable than the best S33 variant S33-6 (S33E). This work would contribute to the further studies on higher thermostability modification of type A feruloyl esterases, especially those from fungi. The thermostable feruloyl esterase variants were expected to be potential candidates for industrial application in prompting the enzymic degradation of plant biomass materials at elevated temperatures.
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  • 14
    Publikationsdatum: 2015-08-13
    Beschreibung: Riemerella anatipestifer infection causes high mortality for ducks which results in major economic losses in the duck industry. In this study, we identified a mutant strain RA-M1 by Tn 4351 transposon mutagenesis, in which the M949_1603 gene encoding glycosyl transferase was inactivated. PCR analysis revealed that M949_1603 gene is specifically existed in R. anatipestifer serotype 1 strains. RA-M1 presented no reactivity to the anti-lipopolysaccharide (LPS) MAb in an indirect ELISA. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) followed by Western blotting demonstrated that RA-M1 LPS had a deficiency in ladder-like binding pattern to rabbit antiserum against R. anatipestifer serotype 1 strain CH3, indicating that the O-antigen structure of RA-M1 was changed. RA-M1 showed significant attenuated virulence in ducks and higher sensitivity to normal duck serum, compared with its parent strain CH3. Furthermore, cross-protection of RA-M1 for R. anatipestifer serotypes 1, 2, and 10 strains was evaluated. Ducks that received two immunizations with inactivated RA-M1 vaccine were 100 % protected from challenge with R. anatipestifer serotype 1 strain WJ4, serotype 2 strain Yb2, and serotype 10 strain HXb2. No changes were observed in the liver, heart, or spleen samples from the protected ducks during autopsy and histological examination. Furthermore, vaccination generated high antibody titers of 1:12,800 against serotypes 1, 2, and 10 strains and enhanced production of interleukin 2 (IL-2) and IL-4 in ducks. These results suggested that M949_1603 gene is associated with serotype 1 O-antigen biosynthesis, and mutant RA-M1 could be used as a novel cross-protection vaccine candidate to protect ducks against R. anatipestifer infection.
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  • 15
    Publikationsdatum: 2015-08-13
    Beschreibung: Saccharopolyspora spinosa can produce spinosad as a major secondary metabolite, which is an environmentally friendly agent for insect control. Cobalamin-independent methionine synthase (MetE) is an important enzyme in methionine biosynthesis, and this enzyme is probably closely related to spinosad production. In this study, its corresponding gene metE was inactivated, which resulted in a rapid growth and glucose utilisation rate and almost loss of spinosad production. A label-free quantitative proteomics-based approach was employed to obtain insights into the mechanism by which the metabolic network adapts to the absence of MetE. A total of 1440 proteins were detected from wild-type and Δ metE mutant strains at three time points: stationary phase of Δ metE mutant strain (S1 Δ metE , 67 h), first stationary phase of wild-type strain (S1 WT , 67 h) and second stationary phase of wild-type strain (S2 WT , 100 h). Protein expression patterns were determined using an exponentially modified protein abundance index (emPAI) and analysed by comparing S1 Δ metE /S1 WT and S1 Δ metE /S2 WT . Results showed that differentially expressed enzymes were mainly involved in primary metabolism and genetic information processing. This study demonstrated that the role of MetE is not restricted to methionine biosynthesis but rather is involved in global metabolic regulation in S. spinosa .
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  • 16
    Publikationsdatum: 2015-08-13
    Beschreibung: Chlorella vulgaris encapsulated in alginate beads were added into a bioreactor treating synthetic wastewater using Pseudomonas putida . A symbiotic CO 2 /O 2 gas exchange was established between the two microorganisms for photosynthetic aeration of wastewater. During batch operation, glucose removal efficiency in the bioreactor improved from 50 % in 12 h without aeration to 100 % in 6 h, when the bioreactor was aerated photosynthetically. During continuous operation, the bioreactor was operated at a low hydraulic retention time of 3.3 h at feed concentrations of 250 and 500 mg/L glucose. The removal efficiency at 500 mg/L increased from 73 % without aeration to 100 % in the presence of immobilized microalgae. The initial microalgae concentration was critical to achieve adequate aeration, and the removal rate increased with increasing microalgae concentration. The highest removal rate of 142 mg/L-h glucose was achieved at an initial microalgae concentration of 190 mg/L. Quantification of microalgae growth in the alginate beads indicated an exponential growth during symbiosis, indicating that the bioreactor performance was limited by oxygen production rates. Under symbiotic conditions, the chlorophyll content of the immobilized microalgae increased by more than 30 %. These results indicate that immobilized microalgae in symbiosis with heterotrophic bacteria are promising in wastewater aeration.
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  • 17
    Publikationsdatum: 2015-08-04
    Beschreibung: The microbiological production of 2,3-butanediol (2,3-BDO) has attracted considerable attention as an alternative way to produce high-value chemicals from renewable sources. Among the number of 2,3-BDO-producing microorganisms, Klebsiella pneumoniae has been studied most extensively and is known to produce large quantity of 2,3-BDO from a range of substrates. On the other hand, the pathogenic characteristics of the bacteria have limited its industrial applications. In this study, two major virulence traits, outer core LPS and fimbriae, were removed through homologous recombination from 2,3-BDO-producing K. pneumoniae 2242 to expand its uses to the industrial scale. The K. pneumoniae 2242 ∆wabG mutant strain was found to have an impaired capsule, which significantly reduced its ability to bind to the mucous layer and evade the phagocytic activity of macrophage. The association with the human ileocecal epithelial cell, HCT-8, and the bladder epithelial cell, T-24, was also reduced dramatically in the K. pneumoniae 2242 ∆fimA mutant strain that was devoid of fimbriae. However, the growth rate and production yield for 2,3-BDO were unaffected. The K. pneumoniae strains developed in this study, which are devoid of the major virulence factors, have a high potential for the efficient and sustainable production of 2,3-BDO.
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  • 18
    Publikationsdatum: 2015-08-04
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  • 19
    Publikationsdatum: 2015-08-04
    Beschreibung: Various food proteins including, e.g. gluten, collagen and casein are rich in l -proline residues. Due to the cyclic structure of proline, these proteins are well protected from enzymatic degradation by typical digestive enzymes. Proline-specific peptidases (PsP) belong to different families of hydrolases acting on peptide bonds (EC 3.4.x.x). They occur in various organisms including bacteria, fungi, plants and insects. Based on their biochemical characteristics, PsP type enzymes are further grouped into different subclasses of which prolyl aminopeptidases (EC 3.4.11.5, PAP), prolyl carboxypeptidases (EC 3.4.17.16, PCP) and prolyl oligopeptidases/prolyl endopeptidases (EC 3.4.21.26, POP/PEP) are of major interest for applications in food biotechnology. This mini review summarises the biochemical assays employed for these subclasses of PsP and their structural properties and the reaction mechanisms. A special focus was set on PsP derived from fungi and insects and important industrial applications in the field of food biotechnology. The degradation of gluten and collagen as well as the hydrolysis of bitter peptides are discussed.
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  • 20
    Publikationsdatum: 2015-08-04
    Beschreibung: The paper describes the preparation of new probiotic formulations based on chitosan-coated alginate microcapsules containing three different probiotic strains, Lactobacillus plantarum PBS067, Lactobacillus rhamnosus PBS070, and Bifidobacterium animalis subsp. lactis PBS075 taken individually and as a mixture of them. The effects of microencapsulation on the viability of the strains in conditions simulating the gastrointestinal tract and under industrial processes conditions were studied. In addition, an evaluation of their probiotic properties was also investigated by in vitro tests on the human intestinal cell line HT-29 to explore the effect of microencapsulation on health beneficial effect of the considered strains. Non-encapsulated cells were completely destroyed when exposed to simulated gastric juice and other stress conditions, while encapsulated cells exhibited a significantly higher resistance to artificial intestinal juice and heat and osmotic treatment. Moreover, in this study, the effect of the various microencapsulated probiotic strain formulations was compared with analogous formulations also containing the β-glucan Pleuran. The microencapsulation effectively protected the selected bacteria, as single strain and as a mixture of the three strains in both the formulations with and without Pleuran, from simulating gastrointestinal tract and industrial process conditions in delivering the viable cells without any significant adverse effect on their functionalities. The comparative study of the immunomodulatory properties of each single strain and the mixture of the three strains revealed a synergistic effect of the probiotic mixture, but no appreciable difference between the two kinds of formulations could be detected, as the effect of Pleuran is covered by the higher potential of the probiotic strains.
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  • 21
    Publikationsdatum: 2015-08-04
    Beschreibung: Strategies for bioremediation of atrazine, a pesticide commonly polluting groundwater in low concentrations, were studied in two boreal nonagricultural soils. Atrazine was not mineralized in soil without bioremediation treatments. In biostimulation treatment with molasses, up to 52 % of atrazine was mineralized at 10 °C, even though the degradation gene copy numbers did not increase. Incubations with radioactively labeled atrazine followed by microautoradiographic analysis revealed that bioremediation strategies increased the relative proportion of active degraders from 0.3 up to 1.9 % of the total bacterial count. These results indicate that atrazine degradation might not solely be facilitated by atzA / trzN – atzB genes. In combined biostimulation treatment using citrate or molasses and augmentation with Pseudomonas citronellolis ADP or Arthrobacter aurescens strain TC1, up to 76 % of atrazine was mineralized at 30 °C, and the atrazine degradation gene numbers increased up to 10 7  copies g −1 soil. Clone libraries from passive samplers in groundwater monitoring wells revealed the presence of phylogenetic groups formerly shown to include atrazine degraders, and the presence of atrazine degradation genes atzA and atzB . These results show that the mineralization of low concentrations of atrazine in the groundwater zone at low temperatures is possible by bioremediation treatments.
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  • 22
    Publikationsdatum: 2015-08-04
    Beschreibung: We expressed a glucansucrase, DsrI, from Leuconostoc mesenteroides that catalyzes formation of water-insoluble glucans from sucrose using a nisin-controlled gene expression system in Lactococcus lactis . These polymers have potential for production of biodegradable gels, fibers, and films. We optimized production of DsrI using several different background vectors, signal peptides, strains, induction conditions, and bioreactor parameters to increase extracellular accumulation. Optimal production of the enzyme utilized a high-copy plasmid, pMSP3535H3, which contains a nisin immunity gene, L. lactis LM0230, and bioreactors maintained at pH 6.0 to stabilize the enzyme. We were able to significantly improve growth using the lactic acid inhibitor heme and by continuous removal of lactic acid with anion exchange resins, but enzyme production was less than the controls. The recombinant enzyme under optimized conditions accumulated in the culture medium to approximately 380 mg/L, which was over 150-fold higher compared to the native L. mesenteroides strain. Methods are also included for purification of DsrI utilizing the glucan-binding domain of the enzyme.
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  • 23
    Publikationsdatum: 2015-08-04
    Beschreibung: Glutathione is a valuable tripeptide widely used in the pharmaceutical, food, and cosmetic industries. In industrial fermentation, glutathione is currently produced primarily using the yeast Saccharomyces cerevisiae . Intracellular glutathione exists in two forms; the majority is present as reduced glutathione (GSH) and a small amount is present as oxidized glutathione (GSSG). However, GSSG is more stable than GSH and is a more attractive form for the storage of glutathione extracted from yeast cells after fermentation. In this study, intracellular GSSG content was improved by engineering thiol oxidization metabolism in yeast. An engineered strain producing high amounts of glutathione from over-expression of glutathione synthases and lacking glutathione reductase was used as a platform strain. Additional over-expression of thiol oxidase (1.8.3.2) genes ERV1 or ERO1 increased the GSSG content by 2.9-fold and 2.0-fold, respectively, compared with the platform strain, without decreasing cell growth. However, over-expression of thiol oxidase gene ERV2 showed almost no effect on the GSSG content. Interestingly, ERO1 over-expression did not decrease the GSH content, raising the total glutathione content of the cell, but ERV1 over-expression decreased the GSH content, balancing the increase in the GSSG content. Furthermore, the increase in the GSSG content due to ERO1 over-expression was enhanced by additional over-expression of the gene encoding Pdi1, whose reduced form activates Ero1 in the endoplasmic reticulum. These results indicate that engineering the thiol redox metabolism of S. cerevisiae improves GSSG and is critical to increasing the total productivity and stability of glutathione.
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  • 24
    Publikationsdatum: 2015-08-04
    Beschreibung: Baculoviruses have a long history of safe use as specific, environmentally friendly insecticides that provide alternatives to chemical pesticides for controlling insect pests. However, their use has been limited by several factors, particularly their slow pathogenicity. In this study, we constructed a recombinant Bombyx mori nucleopolyhedrovirus (BmNPV) and an Autographa californica multiple nucleopolyhedrovirus (AcMNPV) that expressed an insect-specific cyto-insectotoxin (Cit1a) from the venom of the central Asian spider Lachesana tarabaevi . Cit1a is a comparatively long linear cytolytic molecule that contains a predicted α-helix structure composed of two short membrane-acting antimicrobial peptides (MAMPs) that are joined together in a “head-to-tail” shape. Cit1a fused to polyhedrin gene ( polh ) ( polh - cit1a ) was expressed in the nuclei as polyhedra in silkworm larvae, Bm5 and Sf9 cells. An early death of Bm5 and Sf9 cells by recombinant BmNPV/Polh-Cit1a and AcMNPV/Polh-Cit1a was observed compared with control viruses that lacked the toxin gene. The infected cells showed a loss of cytoplasm, membrane integrity, and structural changes, suggesting that recombinant baculovirus-infected cells were killed by the necrosis caused by Cit1a. In addition, the BmNPV/Polh-Cit1a showed a significant reduction in the median lethal time (LT 50 ) against silkworm larvae compared with those of control BmNPV that lacked the cit1a gene.
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  • 25
    Publikationsdatum: 2015-08-04
    Beschreibung: Organic carbon, nitrogen, and sulfur are highly concentrated in municipal solid waste (MSW) landfill leachate, which usually frustrates conventional leachate treatment technologies from the perspective of energy costs. Therefore, the possibility of converting leachate to a new energy source via microbial fuel cell (MFC) technology has been examined recently. This paper summarizes the power output and energy recovery efficiency of the leachate-fed MFCs according to different feeding patterns, cell structures, and loading rates. Also, we assess potential energy-generating chemicals in leachate like nitrogen and sulfur compounds and propose alternative pathways, which may lift strict ratios between organic carbon and nitrogen content in conventional denitrification of leachate and are expected to achieve a higher voltage than traditional organic-oxygen based cells. Although currently power output of leachate-fed MFCs is limited, it seems well possible that dynamic characteristics of MSW leachates and microbial physiologies underlying some bio-electrochemically efficient activities (e.g., direct interspecies electron transfer) could be stimulated in MFC systems to improve the present status.
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  • 26
    facet.materialart.
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    Springer
    Publikationsdatum: 2015-08-04
    Beschreibung: A Higgs field of particle physics can play the role of the inflaton in the early universe if it is non-minimally coupled to gravity. The Higgs inflation scenario predicts a small tensor to scalar ratio: \(r\simeq 0.003\) . Although this value is consistent with the upper bound \(r〈0.12\) given by the BICEP2/ Keck Array and Planck data, it is not at their maximum likelihood point: \(r\simeq 0.05\) . Inflationary observables depend not only on the inflationary models, but they also depend on the initial conditions of inflation. Changing the initial state of inflation can improve the value of r . In this work, we study the Higgs inflation model under general initial conditions and show that there is a subset of these general initial conditions which leads to enhancement of r . Then we show that this region of parameter space is consistent with a non-Gaussianity bound.
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  • 27
    Publikationsdatum: 2015-08-04
    Beschreibung: When Morris and Thorne first proposed that traversable wormholes may be actual physical objects, they concentrated on the geometry by specifying the shape and redshift functions. This mathematical approach necessarily raises questions regarding the determination of the required stress-energy tensor. This paper discusses a natural way to obtain a complete wormhole solution by assuming that the wormhole (1) is supported by generalized Chaplygin gas and (2) admits conformal Killing vectors.
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  • 28
    Publikationsdatum: 2015-08-05
    Beschreibung: Many filamentous fungi produce only conidia for dispersal and survival in vitro or in vivo. Here, we show that the developmental regulator WetA and the velvet protein VosA are not only required for conidial maturation but indispensable for conidiation in Beauveria bassiana , a filamentous entomopathogen. Deletion of wetA or vosA resulted in more than 90 % transcriptional depression of brlA and abaA , two activator genes in the central developmental pathway, during the critical period of conidiophore development and conidiation. Consequently, Δ wetA and Δ vosA strains lost 98 % in and 88 % of their conidiation capacities under optimal culture conditions, respectively. The conidia of Δ wetA showed more defective features than those of Δ vosA , including smaller size, lesser density, lower hydrophobicity, and impaired cell walls although intracellular trehalose content decreased more in the aging culture of Δ vosA than of Δ wetA . As a result, conidial sensitivity to cell wall perturbation was elevated in Δ wetA but unaffected in Δ vosA , which produced conidia more sensitive to the oxidant menadione and the wet-heat stress at 45 °C. Both deletion mutants showed similar defects in conidial tolerance to high osmolarity or UV-B irradiation but no change in conidial sensitivity to the other oxidant H 2 O 2 or the fungicide carbendazim. Moreover, Δ wetA lost more virulence to Galleria mellonella larvae than Δ vosA . All these phenotypical changes were restored by either wetA or vosA complementation. Taken together, WetA and VosA are indispensable for asexual development and contribute differentially to conidial quality and hence the biological control potential of B. bassiana against insect pests.
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  • 29
    facet.materialart.
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    Springer
    Publikationsdatum: 2015-08-08
    Beschreibung: In this article, we study the charmed baryon states \(\Lambda _c(2625)\) and \(\Xi _c(2815)\) with the spin-parity \({3\over 2}^-\) by subtracting the contributions from the corresponding charmed baryon states with the spin-parity \({3\over 2}^+\) using the QCD sum rules, and suggest a formula \( \mu =\sqrt{M_{\Lambda _c/\Xi _c}^2-{\mathbb {M}}_c^2}\) with the effective mass \({\mathbb {M}}_c=1.8\,\mathrm {GeV}\) to determine the energy scales of the QCD spectral densities, and make reasonable predictions for the masses and pole residues. The numerical results indicate that the \(\Lambda _c(2625)\) and \(\Xi _c(2815)\) have at least two remarkable under-structures.
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  • 30
    Publikationsdatum: 2015-08-08
    Beschreibung: We study the radiative leptonic \(B_c\rightarrow \gamma \ell {\bar{\nu }}\) decays in nonrelativistic QCD effective field theory, and we explore the contribution from a fast-moving photon. As a result, interactions between the photon and the heavy quarks can be integrated out, resulting in the factorization formula for the decay amplitude. We calculate not only the relevant short-distance coefficients at leading order and next-to-leading order in \(\alpha _s\) , but also the nonrelativistic corrections at the order \(|\mathrm {v}|^2\) in our analysis. We find that the QCD corrections can significantly decrease the branching ratio, and this is of great importance in extracting the long-distance operator matrix elements of \(B_c\) . For phenomenological application, we present our results for the photon energy, lepton energy and lepton-neutrino invariant mass distribution.
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  • 31
    Publikationsdatum: 2015-08-21
    Beschreibung: The effect of chitosan with different molecular weights and other natural substances on dextransucrase (DSase) activity from a representative oral pathogen Streptococcus mutans was elucidated. Among other bioactive substances, amino-monosaccharides such as glucosamine, mannosamine, and galactosamine exerted the enzyme inhibitory activity over 95 % of DSase. The specified hydrolysates derived from the hydrolysis of high molecular weight chitosan (HMWC) designated to CTSN, CTSN-P, CTSN-B, and CTSN-S with different molecular weights ranging from 3 to 8 kDa showed the similar inhibitory activity toward DSase. Also, the hyaluronic acid (MW 8.9 kDa), sulfated chitin, and amino-monosaccharides demonstrated the significant activity, CTSN, CTSN-P, CTSN-B, and CTSN-S are of potent bioactive substances that can be prepared in the cheapest way compared with other molecules tested available for antibacterial agent useful for human oral health.
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  • 32
    Publikationsdatum: 2015-08-21
    Beschreibung: Rifamycin is a broad-spectrum antimicrobial drug produced commercially by submerged fermentation where the yields are far less in comparison to its demand in human drug therapy. Addressing the need, sequential mutational strain improvement was carried using UV and EtBr that resulted in improved strain yielding rifamycin SV up to 4.32 g/L. Further optimization of six important fermentation factors was followed which include temperature, agitation, inoculum level, period of fermentation, inorganic nitrogen source and amino acids. For the first time, we report a maximum yield of 5.32 g/L of rifamycin SV. Among the amino acids, proline known for its slowest assimilation by Amycolatopsis mediterranei produced the highest improvement in antibiotic yields. Following mutational strain improvement and process optimization, a total of 3.8-fold increase in antibiotic titre was achieved. Following a conventional procedure of mutational strain improvement, highest yield of rifamycin SV was reported by optimizing submerged fermentation process.
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  • 33
    Publikationsdatum: 2015-08-21
    Beschreibung: A new molecularly imprinted polymer (MIP), prepared by hispidin as the template molecule, was synthesized and applied as an adsorbent phase for solid phase extraction (SPE) to isolate and enrich hispidin from eight species of mushrooms. The optimization of synthesis and the adsorption behaviors of the MIPs were investigated in detail. In comparison with C 18 -SPE, MIP-SPE displayed high selectivity and good affinity for hispidin for extract of Phellinus igniarius. The antioxidant activity of the extracts after using the MIPs was evaluated by free radical scavenging activity, and inhibition of erythrocyte hemolysis, and lipid peroxidation. This developed method provided a rapid, selective, and effective approach for separation and enrichment of active compounds from the natural products.
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  • 34
    Publikationsdatum: 2015-08-23
    Beschreibung: We point out a weak side of the commonly used determination of scalar cosmological perturbations lying in the fact that their average values can be nonzero for some matter distributions. It is shown that introduction of the finite-range gravitational potential instead of the infinite-range one resolves this problem. The concrete illustrative density profile is investigated in detail in this connection.
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  • 35
    Publikationsdatum: 2015-08-23
    Beschreibung: A consistent BPS formalism to study the existence of topological axially symmetric vortices in generalized versions of the Born–Infeld–Higgs electrodynamics is implemented. Such a generalization modifies the field dynamics via the introduction of three nonnegative functions depending only in the Higgs field, namely, \(G(|\phi |)\) , \(w(|\phi |) \) , and \(V(|\phi |)\) . A set of first-order differential equations is attained when these functions satisfy a constraint related to the Ampère law. Such a constraint allows one to minimize the system’s energy in such way that it becomes proportional to the magnetic flux. Our results provides an enhancement of the role of topological vortex solutions in Born–Infeld–Higgs electrodynamics. Finally, we analyze a set of models entailing the recovery of a generalized version of Maxwell–Higgs electrodynamics in a certain limit of the theory.
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  • 36
    facet.materialart.
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    Springer
    Publikationsdatum: 2015-08-25
    Beschreibung: I put forward a qualitatively new dynamical mechanism for solving the electroweak hierarchy problem that does not require new physics at the electroweak scale. I argue that the infrared fluctuations of the gravitational field may provide a partial screening of the Higgs mass, similar to the infrared screening of the electric charge in quantum electrodynamics.
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  • 37
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    Springer
    Publikationsdatum: 2015-08-25
    Beschreibung: It is thought that the spacetime geometry around black hole candidates is described by the Kerr solution, but an observational confirmation is still missing. Today, the continuum-fitting method and the analysis of the iron K \(\alpha \) line cannot unambiguously test the Kerr paradigm because of the degeneracy among the parameters of the system, in the sense that it is impossible with current X-ray data to distinguish a Kerr black hole from a non-Kerr object with different values of the model parameters. In this paper, we study the possibility of testing the Kerr nature of black hole candidates with X-ray spectropolarimetric measurements. Within our simplified model that does not include the effect of returning radiation, we find that it is impossible to test the Kerr metric and the problem is still the strong correlation between the spin and possible deviations from the Kerr geometry. Moreover, the correlation is very similar to that of the other two techniques, which makes the combination of different measurements not very helpful. Nevertheless, our results cannot be taken as conclusive and, in order to arrive at a final answer, the effect of returning radiation should be properly taken into account.
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  • 38
    Publikationsdatum: 2015-08-21
    Beschreibung: Vinyl chloride (VC), a known human carcinogen, is a common and persistent groundwater pollutant at many chlorinated solvent contaminated sites. The remediation of such sites is challenging because of the lack of knowledge on the microorganisms responsible for in situ VC degradation. To address this, the microorganisms involved in carbon assimilation from VC were investigated in a culture enriched from contaminated site groundwater using stable isotope probing (SIP) and high-throughput sequencing. The mixed culture was added to aerobic media, and these were amended with labeled ( 13 C-VC) or unlabeled VC ( 12 C-VC). The cultures were sacrificed on days 15, 32, and 45 for DNA extraction. DNA extracts and SIP ultracentrifugation fractions were subject to sequencing as well as quantitative PCR (qPCR) for a functional gene linked to VC-assimilation ( etnE ). The gene etnE encodes for epoxyalkane coenzyme M transferase, a critical enzyme in the pathway for VC degradation. The relative abundance of phylotypes was compared across ultracentrifugation fractions obtained from the 13 C-VC- and 12 C-VC-amended cultures. Four phylotypes were more abundant in the heavy fractions (those of greater buoyant density) from the 13 C-VC-amended cultures compared to those from the 12 C-VC-amended cultures, including Nocardioides , Brevundimonas , Tissierella , and Rhodoferax. Therefore, both a previously identified VC-assimilating genus ( Nocardioides ) and novel microorganisms were responsible for carbon uptake. Enrichment of etnE with time was observed in the heavy fractions, and etnE sequences illustrated that VC-assimilators harbor similar Nocardioides- like etnE . This research provides novel data on the microorganisms able to assimilate carbon from VC.
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  • 39
    Publikationsdatum: 2015-08-21
    Beschreibung: As antibiotic resistance continues to spread globally, there is growing interest in the potential to limit the spread of antibiotic resistance genes (ARGs) from wastewater sources. In particular, operational conditions during sludge digestion may serve to discourage selection of resistant bacteria, reduce horizontal transfer of ARGs, and aid in hydrolysis of DNA. This study applied metagenomic analysis to examine the removal efficiency of ARGs through thermophilic and mesophilic anaerobic digestion using bench-scale reactors. Although the relative abundance of various ARGs shifted from influent to effluent sludge, there was no measureable change in the abundance of total ARGs or their diversity in either the thermophilic or mesophilic treatment. Among the 35 major ARG subtypes detected in feed sludge, substantial reductions (removal efficiency 〉90 %) of 8 and 13 ARGs were achieved by thermophilic and mesophilic digestion, respectively. However, resistance genes of aad A, mac B, and sul 1 were enriched during the thermophilic anaerobic digestion, while resistance genes of erythromycin esterase type I, sul 1, and tet M were enriched during the mesophilic anaerobic digestion. Efflux pump remained to be the major antibiotic resistance mechanism in sludge samples, but the portion of ARGs encoding resistance via target modification increased in the anaerobically digested sludge relative to the feed. Metagenomic analysis provided insight into the potential for anaerobic digestion to mitigate a broad array of ARGs.
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  • 40
    Publikationsdatum: 2015-08-21
    Beschreibung: Yersinia pestis , an infectious bacterium that is a causative agent of plague, a disease which has been shown to be one of the most feared in history and which has caused millions of deaths. The capsule-like fraction 1 (F1) antigen expressed by Y. pestis is a known specific marker for the identification of the bacteria; therefore, the detection of F1 is important for Y. pestis recognition. In this study, a rapid, sensitive, and specific technique, the lateral flow assay (LFA), was successfully developed to detect Y. pestis by the recombinant F1 antigen. The assay that utilized an anti-F1 polyclonal antibody (Pab) to identify the bacteria was based on a double-antibody sandwich format on a nitrocellulose membrane. With the LFA method, 50 ng/ml of recombinant F1 protein and 10 5 CFU/mL of Y. pestis could be detected in less than 10 min. This assay also showed no cross-reaction with other Yersinia spp. or with some selected capsule-producing Enterobacteriaceae strains. Furthermore, detection of Y. pestis in simulated samples has been evaluated. The detection sensitivity of Y. pestis in various matrices was 10 5 CFU/mL, which was identical to that in PBS buffer. The results obtained suggest that LFA is an excellent tool for detection of Y. pestis contamination in an environment and hence can be used to monitor plague diseases when they emerge.
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  • 41
    Publikationsdatum: 2015-08-21
    Beschreibung: Microbial production of biodiesel from renewable feedstock has attracted intensive attention. Biodiesel is known to be produced from short-chain alcohols and fatty acyl-CoAs through the expression of wax ester synthase/fatty acyl-CoA: diacylglycerol acyltransferase that catalyzes the esterification of short-chain alcohols and fatty acyl-CoAs. Here, we engineered Escherichia coli to produce various fatty alcohol acetate esters, which depend on the expression of Saccharomyces cerevisiae alcohol acetyltransferase ATF1 that catalyzes the esterification of fatty alcohols and acetyl-CoA. The fatty acid biosynthetic pathways generate fatty acyl-ACPs, fatty acyl-CoAs, or fatty acids, which can be converted to fatty alcohols by fatty acyl-CoA reductase, fatty acyl-ACP reductase, or carboxylic acid reductase, respectively. This study showed the biosynthesis of biodiesel from three fatty acid biosynthetic pathway intermediates.
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  • 42
    Publikationsdatum: 2015-08-21
    Beschreibung: We investigate unitarity within the complex-mass scheme, a convenient universal scheme for perturbative calculations involving unstable particles in quantum field theory which guarantees exact gauge invariance. Since this scheme requires one to introduce complex masses and complex couplings, the Cutkosky cutting rules, which express perturbative unitarity in theories of stable particles, are no longer valid. We derive corresponding rules for scalar theories with unstable particles based on Veltman’s largest-time equation and prove unitarity in this framework.
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  • 43
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    Springer
    Publikationsdatum: 2015-08-21
    Beschreibung: We compute the decays \({B\rightarrow D^*_0}\) and \({B\rightarrow D^*_2}\) with finite masses for the b and c quarks. We first discuss the spectral properties of both the B meson as a function of its momentum and the \(D^*_0\) and \(D^*_2\) at rest. We compute the theoretical formulae leading to the decay amplitudes from the three-point and two-point correlators. We then compute the amplitudes at zero recoil of \({B\rightarrow D^*_0}\) , which turns out not to be vanishing contrary to what happens in the heavy quark limit. This opens the possibility to get better agreement with experiment. To improve the continuum limit we have added a set of data with smaller lattice spacing. The \({B\rightarrow D^*_2}\) vanishes at zero recoil and we show a convincing signal but only slightly more than 1 sigma from 0. In order to reach quantitatively significant results we plan to exploit fully smaller lattice spacings as well as another lattice regularisation.
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  • 44
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    Springer
    Publikationsdatum: 2015-08-23
    Beschreibung: We present a simulation study of the prospects for the mass measurement of TeV-scale light-flavored right-handed squarks at a 3 TeV \(e^+e^-\) collider based on CLIC technology. In the considered model, these particles decay into their standard-model counterparts and the lightest neutralino, resulting in a signature of two jets plus missing energy. The analysis is based on full GEANT4 simulations of the CLIC_ILD detector concept, including Standard Model physics backgrounds and beam-induced hadronic backgrounds from two-photon processes. The analysis serves as a generic benchmark for the reconstruction of highly energetic jets in events with substantial missing energy. Several jet finding algorithms were evaluated, with the longitudinally invariant \(k_t\) algorithm showing a high degree of robustness towards beam-induced background while preserving the features typically found in algorithms developed for \(e^+e^-\) collisions. The presented study of the reconstruction of light-flavored squarks shows that for TeV-scale squark masses, sub-percent accuracy on the mass measurement can be achieved at CLIC.
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  • 45
    Publikationsdatum: 2015-08-23
    Beschreibung: We evaluate the Hadamard function and the vacuum expectation value (VEV) of the current density for a charged scalar field, induced by flat boundaries in spacetimes with an arbitrary number of toroidally compactified spatial dimensions. The field operator obeys the Robin conditions on the boundaries and quasiperiodicity conditions with general phases along compact dimensions. In addition, the presence of a constant gauge field is assumed. The latter induces Aharonov–Bohm-type effect on the VEVs. There is a region in the space of the parameters in Robin boundary conditions where the vacuum state becomes unstable. The stability condition depends on the lengths of compact dimensions and is less restrictive than that for background with trivial topology. The vacuum current density is a periodic function of the magnetic flux, enclosed by compact dimensions, with the period equal to the flux quantum. It is explicitly decomposed into the boundary-free and boundary-induced contributions. In sharp contrast to the VEVs of the field squared and the energy-momentum tensor, the current density does not contain surface divergences. Moreover, for Dirichlet condition it vanishes on the boundaries. The normal derivative of the current density on the boundaries vanish for both Dirichlet and Neumann conditions and is nonzero for general Robin conditions. When the separation between the plates is smaller than other length scales, the behavior of the current density is essentially different for non-Neumann and Neumann boundary conditions. In the former case, the total current density in the region between the plates tends to zero. For Neumann boundary condition on both plates, the current density is dominated by the interference part and is inversely proportional to the separation.
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  • 46
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    Publikationsdatum: 2015-08-25
    Beschreibung: A small tensor-to-scalar ratio r may lead to distinctive phenomenology of high-scale supersymmetry. Assuming the same origin of SUSY breaking between the inflation and visible sector, we show model independent features. The simplest hybrid inflation, together with a new linear term for the inflaton field which is induced by a large gravitino mass, is shown to be consistent with all experimental data for r of order \(10^{-5}\) . For superpartner masses far above the weak scale we find that the reheating temperature after inflation might be below the value required by thermal leptogenesis if the inflaton decays to its products perturbatively, but above it if the decay is non-perturbatively instead. Remarkably, the gravitino overproduction can be evaded in such high-scale supersymmetry because of the kinematically blocking effect.
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  • 47
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    Springer
    Publikationsdatum: 2015-08-25
    Beschreibung: We show how leading radiative corrections can be implemented in the general description of \(h\rightarrow 4\ell \) decays by means of pseudo observables (PO). With the inclusion of such corrections, the PO description of \(h\rightarrow 4\ell \) decays can be matched to next-to-leading-order electroweak calculations both within and beyond the Standard Model (SM). In particular, we demonstrate that with the inclusion of such corrections the complete next-to-leading-order SM prediction for the \(h\rightarrow 2e2\mu \) dilepton mass spectrum is recovered within \(1\,\%\) accuracy. The impact of radiative corrections for non-standard PO is also briefly discussed.
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  • 48
    Publikationsdatum: 2015-08-14
    Beschreibung: Epidermal growth factor (EGF) ameliorates stress and prevents incomplete gastrointestinal development in early-weaned piglets in commercial swine farming. This study aimed to further analyze the biological activities of intracellularly expressed EGF (IE-EGF), extracellularly expressed EGF (EE-EGF), and tagged EGF (T-EGF) from Saccharomyces cerevisiae in early-weaned pigs. In this study, we assigned 24 pigs to each of 5 groups that were provided a basic diet (the control group) or a diet supplemented with empty vector-expressing S. cerevisia e [the INVSc1(EV) group], T-EGF-expressing S. cerevisiae [the INVSc1-TE(−) group], EE-EGF-expressing S. cerevisiae [the INVSc1-EE(+) group], or IE-EGF-expressing S. cerevisiae [the INVSc1-IE(+) group]. All treatments were delivered at a dose of 60 μg EGF/kg body weight (BW) everyday. All the piglets were sacrificed after 21 day to determine their physio-biochemical indexes, immune functions, and intestinal development. In the piglet experiments, recombinant S. cerevisiae survived throughout the intestinal tract. The BW and intestinal development (e.g., mean villous height, crypt depth, villous height:crypt depth ratio (IVR), and total protein, DNA, and RNA contents) of the piglets were significantly enhanced in the INVSc1-IE(+) group compared with the animals in the INVSc1-EE(+) and INVSc1-TE(−) groups ( P  〈 0.05). In addition, increased proliferating cell nuclear antigen (PCNA) staining was observed in the piglets that received the INVSc1-IE(+) treatment (approximately 80 %) compared with those that received the INVSc1-TE(−) (approximately 70 %) and INVSc1-EE(+) treatments (approximately 70 %). The levels of lactate dehydrogenase (LDH), creatine kinase (CK), alkaline phosphatase (ALP), immunoglobulin A (IgA), immunoglobulin M (IgM), and immunoglobulin G (IgG) were also significantly increased in the INVSc1-IE(+) group compared with the INVSc1-EE(+) and INVSc1-TE(−) groups ( P  〈 0.05). Furthermore, the proliferation of piglet enterocytes was also significantly stimulated by both IE-EGF and EE-EGF compared with T-EGF in vitro ( P  〈 0.05). Our data further demonstrate the previously reported hypothesis that IE-EGF is more suitable than EE-EGF or T-EGF for applications in early-weaned pigs.
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  • 49
    Publikationsdatum: 2015-08-14
    Beschreibung: With the rapid development of molecular diagnostic techniques, there is a growing need for quality controls and standards with favorable properties to monitor the entire detection process. In this study, we describe a novel method to produce armored hepatitis B virus (HBV) and human papillomavirus (HPV) DNA for use in nucleic acid tests, which was confirmed to be stable, homogeneous, noninfectious, nuclease resistant, and safe for shipping. We demonstrated that MS2 bacteriophage could successfully package double-stranded DNA of 1.3-, 3-, 3.5-, and 6.5-kb length into viral capsids with high reassembly efficiency. This is the first application of RNA bacteriophage MS2 as a platform to encapsulate double-stranded DNA, forming virus-like particles (VLPs) which were indistinguishable from native MS2 capsids in size and morphology. Moreover, by analyzing the interaction mechanism of pac site and the MS2 coat protein (CP), we found that in addition to the recognized initiation signal TR-RNA, TR-DNA can also trigger spontaneous reassembly of CP dimers, providing a more convenient and feasible method of assembly. In conclusion, this straightforward and reliable manufacturing approach makes armored DNA an ideal control and standard for use in clinical laboratory tests and diagnostics, possessing prospects for broad application, especially providing a new platform for the production of quality controls for DNA viruses.
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  • 50
    Publikationsdatum: 2015-08-14
    Beschreibung: Lipids are naturally derived products that offer an attractive, renewable alternative to petroleum-based hydrocarbons. While naturally produced long-chain fatty acids can replace some petroleum analogs, medium-chain fatty acid would more closely match the desired physical and chemical properties of currently employed petroleum products. In this study, we engineered Yarrowia lipolytica , an oleaginous yeast that naturally produces lipids at high titers, to produce medium-chain fatty acids. Five different acyl-acyl carrier protein (ACP) thioesterases with specificity for medium-chain acyl-ACP molecules were expressed in Y. lipolytica , resulting in formation of either decanoic or octanoic acid. These novel fatty acid products were found to comprise up to 40 % of the total cell lipids. Furthermore, the reduction in chain length resulted in a twofold increase in specific lipid productivity in these engineered strains. The medium-chain fatty acids were found to be incorporated into all lipid classes.
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  • 51
    Publikationsdatum: 2015-08-14
    Beschreibung: Long-term stable cell growth and production of vindoline, catharanthine, and ajmalicine of cambial meristematic cells (CMCs) from Catharanthus roseus were observed after 2 years of culture. C. roseus CMCs were treated with β-cyclodextrin (β-CD) and methyl jasmonate (MeJA) individually or in combination and were cultured both in conventional Erlenmeyer flasks (100, 250, and 500 mL) and in a 5-L stirred hybrid airlift bioreactor. CMCs of C. roseus cultured in the bioreactor showed higher yields of vindoline, catharanthine, and ajmalicine than those cultured in flasks. CMCs of C. roseus cultured in the bioreactor and treated with 10 mM β-CD and 150 μM MeJA gave the highest yields of vindoline (7.45 mg/L), catharanthine (1.76 mg/L), and ajmalicine (58.98 mg/L), concentrations that were 799, 654, and 426 % higher, respectively, than yields of CMCs cultured in 100-mL flasks without elicitors. Quantitative reverse transcription (RT)-PCR showed that β-CD and MeJA upregulated transcription levels of genes related to the biosynthesis of terpenoid indole alkaloids (TIAs). This is the first study to report that β-CD induced the generation of NO, which plays an important role in mediating the production of TIAs in C. roseus CMCs. These results suggest that β-CD and MeJA can enhance the production of TIAs in CMCs of C. roseus , and thus, CMCs of C. roseus have significant potential to be an industrial platform for production of bioactive alkaloids.
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  • 52
    Publikationsdatum: 2015-08-14
    Beschreibung: Mechanisms of glutathione (GSH) over-accumulation in mutant Saccharomyces cerevisiae Y518 screened by ultraviolet and nitrosoguanidine-induced random mutagenesis were studied. Y518 accumulated higher levels of GSH and l -cysteine than its wild-type strain. RNA-Seq and pathway enrichment analysis indicated a difference in the expression of key genes involved in cysteine production, the GSH biosynthesis pathway, and antioxidation processes. GSH1 , MET17 , CYS4 , GPX2 , CTT1 , TRX2 , and SOD1 and the transcriptional activators SKN7 and YAP1 were up-regulated in the mutant. Moreover, Y518 showed a dysfunctional respiratory chain resulting from dramatically weakened activity of complex III and significant elevation of intracellular reactive oxygen species (ROS) levels. The supplementation of antimycin A in the culture of the parent strain showed equivalent changes of ROS and GSH level. This study indicates that defective complex III prompts abundant endogenic ROS generation, which triggers an oxidative stress response and upregulation of gene expression associated with GSH biosynthesis. This finding may be helpful for developing new strategies for GSH fermentation process optimization or metabolic engineering.
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  • 53
    Publikationsdatum: 2015-08-14
    Beschreibung: Prenyltransferases of the dimethylallyltryptophan synthase (DMATS) superfamily are involved in the biosynthesis of secondary metabolites and contribute as modification enzymes significantly to structural diversity of natural products. They show usually broad specificity toward their aromatic substrates with regiospecific prenylations on aromatic rings. However, most members of this superfamily exhibit a high specificity toward their prenyl donors and usually accept exclusively dimethylallyl diphosphate (DMAPP). Recently, several indole prenyltransferases from this family were also demonstrated to accept unnatural DMAPP analogs such as methylallyl, 2-pentenyl and benzyl diphosphate for alkylation, or benzylation of the indole ring. Partial or complete shift of the substitution position was observed for these enzymes. In this study, we report the acceptance of these DMAPP analogs by two tyrosine O -prenyltransferases TyrPT from Aspergillus niger and SirD from Leptosphaeria maculans for alkylation or benzylation of tyrosine and derivatives. NMR and mass spectrometry (MS) analyses of nine isolated enzyme products confirmed the regiospecific O- or N -alkylation or benzylation at position C-4 of the aromatic ring, which is the same prenylation position of these enzymes in the presence of DMAPP.
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  • 54
    Publikationsdatum: 2015-08-14
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  • 55
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    Publikationsdatum: 2015-08-14
    Beschreibung: A comprehensive review of physics at an \(e^+e^-\) linear collider in the energy range of \(\sqrt{s}=92\)  GeV–3 TeV is presented in view of recent and expected LHC results, experiments from low-energy as well as astroparticle physics. The report focusses in particular on Higgs-boson, top-quark and electroweak precision physics, but also discusses several models of beyond the standard model physics such as supersymmetry, little Higgs models and extra gauge bosons. The connection to cosmology has been analysed as well.
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  • 56
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    Publikationsdatum: 2015-08-15
    Beschreibung: We investigate the fragmentation instability of hairy black holes in the theory with a Gauss–Bonnet (GB) term in asymptotically flat spacetime. Our approach is through the non-perturbative fragmentation instability. By this approach, we investigate whether the initial black hole can be broken into two black holes by comparing the entropy of the initial black hole with the sum of those of two fragmented black holes. The relation between the black hole instability and the GB coupling with dilaton hair are presented. We describe the phase diagrams with respect to the mass of the black hole solutions and coupling constants. We find that a perturbatively stable black hole can be unstable under fragmentation.
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  • 57
    Publikationsdatum: 2015-07-30
    Beschreibung: A pulse-shape discrimination method based on artificial neural networks was applied to pulses simulated for different background, signal and signal-like interactions inside a germanium detector. The simulated pulses were used to investigate variations of efficiencies as a function of used training set. It is verified that neural networks are well-suited to identify background pulses in true-coaxial high-purity germanium detectors. The systematic uncertainty on the signal recognition efficiency derived using signal-like evaluation samples from calibration measurements is estimated to be 5 %. This uncertainty is due to differences between signal and calibration samples.
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  • 58
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    Publikationsdatum: 2015-08-05
    Beschreibung: Isolates of Aspergillus species are able to produce a large number of secondary metabolites. The profiles of biosynthetic families of secondary metabolites are species specific, whereas individual secondary metabolite families can occur in other species, even those phylogenetically and ecologically unrelated to Aspergillus . Furthermore, there is a high degree of chemo-consistency from isolate to isolate in a species even though certain metabolite gene clusters are silenced in some isolates. Genome sequencing projects have shown that the diversity of secondary metabolites is much larger in each species than previously thought. The potential of finding even further new bioactive drug candidates in Aspergillus is evident, despite the fact that many secondary metabolites have already been structure elucidated and chemotaxonomic studies have shown that many new secondary metabolites have yet to be characterized. The genus Aspergillus is cladistically holophyletic but phenotypically polythetic and very diverse and is associated to quite different sexual states. Following the one fungus one name system, the genus Aspergillus is restricted to a holophyletic clade that include the morphologically different genera Aspergillus , Dichotomomyces , Phialosimplex , Polypaecilum and Cristaspora . Secondary metabolites common between the subgenera and sections of Aspergillus are surprisingly few, but many metabolites are common to a majority of species within the sections. We call small molecule extrolites in the same biosynthetic family isoextrolites. However, it appears that secondary metabolites from one Aspergillus section have analogous metabolites in other sections (here also called heteroisoextrolites). In this review, we give a genus-wide overview of secondary metabolite production in Aspergillus species. Extrolites appear to have evolved because of ecological challenges rather than being inherited from ancestral species, at least when comparing the species in the different sections of Aspergillus . Within the Aspergillus sections, secondary metabolite pathways seem to inherit from ancestral species, but the profiles of these secondary metabolites are shaped by the biotic and abiotic environment. We hypothesize that many new and unique section-specific small molecule extrolites in each of the Aspergillus will be discovered.
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  • 59
    Publikationsdatum: 2015-08-06
    Beschreibung: Gene amplification using dihydrofolate reductase gene ( dhfr ) and methotrexate (MTX) is widely used for recombinant protein production in mammalian cells and is typically conducted in DHFR-deficient Chinese hamster ovary (CHO) cell lines. Generation of DHFR-deficient cells can be achieved by an expression vector incorporating short hairpin RNA (shRNA) that targets the 3′-untranslated region (UTR) of endogenous dhfr . Thus, shRNAs were designed to target the 3′-UTR of endogenous dhfr , and shRNA-2 efficiently down-regulated dhfr expression in CHO-K1 cells. A single gene copy of shRNA-2 also decreased the translational level of DHFR by 80 % in Flp-In CHO cells. shRNA-2 was then incorporated into a plasmid vector expressing human erythropoietin (EPO) and an exogenous DHFR to develop EPO-producing cells in the Flp-In system. The specific EPO productivity ( q EPO ) was enhanced by stepwise increments of MTX concentration, and differences in the amplification rate were observed in Flp-In CHO cells that expressed shRNA-2. In addition, the q EPO increased by more than 2.5-fold in the presence of 500 nM MTX. The mRNA expression level and gene copy numbers of dhfr were correlated with increased productivity in the cells, which is influenced by inhibition of endogenous dhfr . This study reveals that an expression vector including shRNA that targets the 3′-UTR of endogenous dhfr can enhance the transgene amplification rate and productivity by generating DHFR-deficient cells. This approach may be applied for amplifying the foreign gene in wild-type cell lines as a versatile single-plasmid vector.
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  • 60
    Publikationsdatum: 2015-08-08
    Beschreibung: Biological activities of medicinal mushrooms have been attributed to β-(1→3),(1→6)-glucans that are present in the cell wall of fungi and some plants. Antitumor, immunomodulatory, antimicrobial, antinociception, antiinflammatory, prebiotic, antioxidant, and antidiabetic are some of different properties already described for β-(1→3),(1→6)-glucans. Immune activation systems, including specific β-glucan receptors like Dectin-1, complement (CR3), and Toll (TLR), have been identified to clarify these biological effects. The β-(1→3)-glucans are synthesized by β-(1→3)-glucan synthase (GLS), an enzyme belonging to the glucosyltransferase group, which has a catalytic unit (FKS) and another regulatory (RHO). The mechanisms for adding β-(1→6) branches to the non-reducing ends of the β-(1→3)-glucan chains are unclear until now. Due to the biological importance of β-(1→3),(1→6)-glucan, it is necessary to understand the biochemical and molecular mechanisms of its synthesis, both to optimize the production of bioactive compounds and to develop antifungal drugs that interrupt this process. Therefore, the aim of this review is to gather information about the potential of β-(1→3),(1→6)-glucans, their methods of isolation, purification, and chemical characterization, as well as how these biomolecules are synthesized by fungi and what studies involving biotechnology or molecular biology have contributed to this subject.
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  • 61
    Publikationsdatum: 2015-06-03
    Beschreibung: In this article, we calculate the form factors and the coupling constant of the vertex \(D_{s}^{*}D_{s}\phi \) using the three-point QCD sum rules. We consider the contributions of the vacuum condensates up to dimension 7 in the operator product expansion. And all possible off-shell cases are considered, \(\phi \) , \(D_{s}\) and \(D_{s}^{*}\) , resulting in three different form factors. Then we fit the form factors into analytical functions and extrapolate them into time-like regions, which giving the coupling constant for the process. Our analysis indicates that the coupling constant for this vertex is \(G_{D_{s}^{*}D{_{s}}\phi }=4.12\pm 0.70\,\mathrm{GeV}^{-1}\) . The results of this work are very useful in the other phenomenological analysis. As an application, we calculate the coupling constant for the decay channel \(D_{s}^{*}\rightarrow D_{s}\gamma \) and analyze the width of this decay with the assumption of the vector meson dominance of the intermediate \(\phi (1020)\) . Our final result about the decay width of this decay channel is \(\Gamma =0.59\pm 0.15\,\mathrm{keV}\) .
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  • 62
    Publikationsdatum: 2015-06-06
    Beschreibung: Bluetongue virus (BTV) is the causative agent of bluetongue (BT), an important sheep disease that caused great economic loss to the sheep industry. There are 26 BTV serotypes based on the outer protein VP2. However, the serotypes BTV-1 and BTV-16 are the two most prevalent serotypes in China. Vaccination is the most effective method of preventing viral infections. Therefore, the need for an effective vaccine against BTV is urgent. In this study, DNA vaccines and recombinant fowlpox virus (rFPV) vaccines expressing VP2 alone or VP2 in combination with VP5 or co-expressing the VP2 and VP5 proteins of BTV-1 were evaluated in both mice and sheep. Several strategies were tested in mice, including DNA vaccine prime and boost, rFPV vaccine prime and boost, and DNA vaccine prime and rFPV vaccine boost. We then determined the best vaccine strategy in sheep. Our results indicated that a strategy combining a DNA vaccine prime (co-expressing VP2 and VP5) followed by an rFPV vaccine boost (co-expressing VP2 and VP5) induced a high titer of neutralizing antibodies in sheep. Therefore, our data suggest that a DNA vaccine consisting of a pCAG-(VP2+VP5) prime and an rFPV-(VP2+VP5) boost is an important candidate for the design of a novel vaccine against BTV-1.
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  • 63
    Publikationsdatum: 2015-06-06
    Beschreibung: Numerous species of wild-grown mushrooms are among the most vulnerable organisms for contamination with radiocesium released from a radioactive fallout. A comparison was made on radiocesium as well as the natural gamma ray-emitting radionuclide ( 40 K) activity concentrations in the fruiting bodies of several valued edible Boletus mushrooms collected from the region of Europe and Yunnan Province in China. Data available for the first time for Boletus edulis collected in Yunnan, China, showed a very weak contamination with 137 Cs. Radiocesium concentration activity of B. edulis samples that were collected between 2011 and 2014 in Yunnan ranged from 5.2 ± 1.7 to 10 ± 1 Bq kg −1 dry matter for caps and from 4.7 ± 1.3 to 5.5 ± 1.0 Bq kg −1 dry matter for stipes. The mushrooms Boletus badius , B. edulis , Boletus impolitus , Boletus luridus , Boletus pinophilus , and Boletus reticulatus collected from the European locations between 1995 and 2010 showed two to four orders of magnitude greater radioactivity from 137 Cs compared to B. edulis from Yunnan. The nuclide 40 K in B. badius was equally distributed between the caps and stipes, while for B. edulis , B. impolitus , B. luridus , B. pinophilus , and B. reticulatus , the caps were richer, and for each mushroom, activity concentration seemed to be more or less species-specific.
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  • 64
    Publikationsdatum: 2015-06-08
    Beschreibung: A novel TaqMan-based multiplex real-time PCR method combined with propidium monoazide (PMA) treatment was firstly developed for the simultaneous quantification of viable Vibrio parahaemolyticus and Listeria monocytogenes in raw shrimp. The optimization of PMA concentration showed that 100 μM was considered optimal to effectively inhibit 10 8  CFU/mL dead cells of both bacteria. The high specificity of this method was confirmed on tests using 96 target and non-target strains. The optimized assay could detect as low as 10 1 –10 2  CFU/g of each strain on the artificially contaminated shrimp, and its amplification efficiencies were up to 100 and 106 % for V. parahaemolyticus and L. monocytogenes , respectively. Furthermore, this assay has been successfully applied to describe the behavior of these two pathogens in raw shrimps stored at 4 °C. In conclusion, this PMA TaqMan-based multiplex real-time PCR technique, where the whole procedure takes less than 5 h, provides an effective and rapid tool for monitoring contamination of viable V. parahaemolyticus and L. monocytogenes in seafood, improving seafood safety and protecting public health.
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  • 65
    Publikationsdatum: 2015-06-09
    Beschreibung: A hybrid airlift reactor was adopted to retain aerobic granules in the reactor successfully for continuous operation. It was found that aerobic granules maintained excellent physical structure stability in the continuous-flow reactor with reactor performance as good as batch operation. However, flocs appeared after batch operation was switched to continuous operation, and chemical oxygen demand (COD) in the wastewater was thus removed by co-existed granules and flocs in the reactor. Furthermore, excessive precipitation of CaCO 3 as needled shaped aragonite in the continuous aerobic granular sludge reactor was observed, which led to the further enhancement of settling ability of granules with sludge volume index (SVI) reduction from 32 to 2 ml g −1 but specific oxygen utilization rate (SOUR) decrease from 61 to 23 mg O 2  g −1 MLVSS h −1 . Thus, apart from the physical structure stability, bioactivity stability of granules should be also considered as an important parameter to evaluate the continuous operation of aerobic granular sludge. Furthermore, the decrease in granule polysaccharide content implied that protein was more important for aragonite precipitation. The excessive aragonite precipitation in the continuous-flow reactor could be due to the competition between flocs and granules. In addition, the degradation of polysaccharide in aerobic granules under a continuous-flow mode may also contribute to excessive aragonite precipitation.
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  • 66
    Publikationsdatum: 2015-06-09
    Beschreibung: Extensive N -body simulations are among the key means for the study of numerous astrophysical and cosmological phenomena, so various schemes are developed for possibly higher accuracy computations. We demonstrate the principal possibility for revealing the evolution of a perturbed Hamiltonian system with an accuracy independent on time. The method is based on the Laplace transform and the derivation and analytical solution of an evolution equation in the phase space for the resolvent and using computer algebra.
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  • 67
    Publikationsdatum: 2015-06-09
    Beschreibung: A search for a standard model Higgs boson produced in association with a top-quark pair and decaying to bottom quarks is presented. Events with hadronic jets and one or two oppositely charged leptons are selected from a data sample corresponding to an integrated luminosity of 19.5 \(\,\text {fb}^\text {-1}\) collected by the CMS experiment at the LHC in \(\mathrm {p}\mathrm {p}\) collisions at a centre-of-mass energy of 8 \(\,\hbox {TeV}\) . In order to separate the signal from the larger \(\hbox {t}\overline{\hbox {t}}\)  + jets background, this analysis uses a matrix element method that assigns a probability density value to each reconstructed event under signal or background hypotheses. The ratio between the two values is used in a maximum likelihood fit to extract the signal yield. The results are presented in terms of the measured signal strength modifier, \(\mu \) , relative to the standard model prediction for a Higgs boson mass of 125 \(\,\hbox {GeV}\) . The observed (expected) exclusion limit at a 95 % confidence level is \(\mu 〈4.2\) (3.3), corresponding to a best fit value \(\hat{\mu }=1.2^{+1.6}_{-1.5}\) .
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  • 68
    facet.materialart.
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    Publikationsdatum: 2015-06-09
    Beschreibung: In this paper we are concerned with the effects of an anisotropic pressure on the boundary conditions of the anisotropic Lane–Emden equation and the homology theorem. Some new exact solutions of this equation are derived. Then some of the theorems governing the Newtonian perfect fluid star are extended, taking the anisotropic pressure into account.
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  • 69
    Publikationsdatum: 2015-06-09
    Beschreibung: An optimized digital shaping filter has been developed for the Gerda experiment which searches for neutrinoless double beta decay in \(^{76}\) Ge. The Gerda Phase I energy calibration data have been reprocessed and an average improvement of 0.3 keV in energy resolution (FWHM) corresponding to 10 % at the \(Q\) value for \(0\nu \beta \beta \) decay in \(^{76}\) Ge is obtained. This is possible thanks to the enhanced low-frequency noise rejection of this Zero Area Cusp (ZAC) signal shaping filter.
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  • 70
    Publikationsdatum: 2015-06-09
    Beschreibung: A generalisation of the narrow-width approximation (NWA) is formulated which allows for a consistent treatment of interference effects between nearly mass-degenerate particles in the factorisation of a more complicated process into production and decay parts. It is demonstrated that interference effects of this kind arising in BSM models can be very large, leading to drastic modifications of predictions based on the standard NWA. The application of the generalised NWA is demonstrated both at tree level and at one-loop order for an example process where the neutral Higgs bosons h and H of the MSSM are produced in the decay of a heavy neutralino and subsequently decay into a fermion pair. The generalised NWA, based on on-shell matrix elements or their approximations leading to simple weight factors, is shown to produce UV- and IR-finite results which are numerically close to the result of the full process at tree level and at one-loop order, where an agreement of better than \(1\,\%\) is found for the considered process. The most accurate prediction for this process based on the generalised NWA, taking into account also corrections that are formally of higher orders, is briefly discussed.
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  • 71
    Publikationsdatum: 2015-06-09
    Beschreibung: A new theory of gravity called Eddington-inspired Born–Infeld (EiBI) gravity was recently proposed by Bañados and Ferreira. This theory leads to some exciting new features, such as free of cosmological singularities. In this paper, we first obtain a charged EiBI black hole solution with a nonvanishing cosmological constant when the electromagnetic field is included in. Then based on it, we study the strong gravitational lensing by the asymptotic flat charged EiBI black hole. The strong deflection limit coefficients and observables are shown to closely depend on the additional coupling parameter \(\kappa \) in the EiBI gravity. It is found that, compared with the corresponding charged black hole in general relativity, the positive coupling parameter \(\kappa \) will shrink the black hole horizon and photon sphere. Moreover, the coupling parameter will decrease the angular position and relative magnitudes of the relativistic images, while increase the angular separation, which may shine new light on testing such gravity theory in near future by the astronomical instruments.
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  • 72
    Publikationsdatum: 2015-08-04
    Beschreibung: This manuscript is devoted to the investigation of the Bianchi type I universe in the context of f ( R ,  T ) gravity. For this purpose, we explore the exact solutions of locally rotationally symmetric Bianchi type I spacetime. The modified field equations are solved by assuming an expansion scalar \(\theta \) proportional to the shear scalar \(\sigma \) , which gives \(A=B^n\) , where A ,   B are the metric coefficients and n is an arbitrary constant. In particular, three solutions have been found and physical quantities are calculated in each case.
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  • 73
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    Springer
    Publikationsdatum: 2015-08-04
    Beschreibung: By detecting redshift drift in the spectra of the Lyman- \(\alpha \) forest of distant quasars, the Sandage–Loeb (SL) test directly measures the expansion of the universe, covering the “redshift desert” of \(2 \lesssim z \lesssim 5\) . Thus this method is definitely an important supplement to the other geometric measurements and will play a crucial role in cosmological constraints. In this paper, we quantify the ability of the SL test signal by a CODEX-like spectrograph for constraining interacting dark energy. Four typical interacting dark energy models are considered: (i) \(Q=\gamma H\rho _c\) , (ii) \(Q=\gamma H\rho _{de}\) , (iii) \(Q=\gamma H_0\rho _c\) , and (iv) \(Q=\gamma H_0\rho _{de}\) . The results show that for all the considered interacting dark energy models, relative to the current joint SN  \(+\)  BAO  \(+\)  CMB  \(+\)   \(H_0\) observations, the constraints on \(\Omega _m\) and \(H_0\) would be improved by about 60 and 30–40 %, while the constraints on w and \(\gamma \) would be slightly improved, with a 30-year observation of the SL test. We also explore the impact of the SL test on future joint geometric observations. In this analysis, we take the model with \(Q=\gamma H\rho _c\) as an example, and we simulate future SN and BAO data based on the space-based project WFIRST. We find that with the future geometric constraints, the redshift drift observations would help break the geometric degeneracies in a meaningful way, thus the measurement precisions of \(\Omega _m\) , \(H_0\) , w , and \(\gamma \) could be substantially improved using future probes.
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  • 74
    Publikationsdatum: 2015-08-05
    Beschreibung: Venom, the mucus layer covering the body surface, ink glands, mammary glands, milk, and various animal secretory functions as both a physical and chemical defense barrier against bacteria and virus infections. Previously, several studies reported that l -amino acid oxidases (LAAOs) present in animal secretary fluids have strong antimicrobial activities and selective cytotoxic activities against Gram-positive and Gram-negative bacteria, various pathogenic bacteria, viruses, and parasite species. These LAAOs catalyze oxidative deamination of an l -amino acid substrate with the generation of hydrogen peroxide. The antibacterial activity of LAAOs is completely inhibited by catalase; thus, LAAOs kill bacteria by the hydrogen peroxide generated from the oxidation of l -amino acid substrates. This review focuses on the selective, specific, and local antibacterial actions of various LAAOs that may be used as novel therapeutic agents against infectious diseases. LAAOs that are suitable leads for combating multidrug-resistant bacterial infections are also studied.
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  • 75
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    Springer
    Publikationsdatum: 2015-08-05
    Beschreibung: To identify the nature of the newly observed charged resonance \(Z_c(4200)^+\) , we study its hadronic decays \(Z_c(4200)^+\rightarrow J/\psi \pi ^+, Z_c(4200)^+\rightarrow \eta _c\rho ^+\) and \(Z_c(4200)^+\rightarrow D^+\bar{D}^{*0}\) as a charmonium-like tetraquark state. In the framework of the QCD sum rules, we calculate the three-point functions and extract the coupling constants and decay widths for these interaction vertices. Including all these channels, the full decay width of the \(Z_c(4200)^+\) state is consistent with the experimental value reported by the Belle Collaboration, supporting the tetraquark interpretation of this state.
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  • 76
    Publikationsdatum: 2015-08-07
    Beschreibung: Experiments were designed to validate the two common DNA extraction protocols (CTAB-based method and DNeasy Blood & Tissue Kit) used to effectively recover actinobacterial DNA from sponge samples in order to study the sponge-associated actinobacterial diversity. This was done by artificially spiking sponge samples with actinobacteria (spores, mycelia and a combination of the two). Our results demonstrated that both DNA extraction methods were effective in obtaining DNA from the sponge samples as well as the sponge samples spiked with different amounts of actinobacteria. However, it was noted that in the presence of the sponge, the bacterial 16S rRNA gene could not be amplified unless the combined DNA template was diluted. To test the hypothesis that the extracted sponge DNA contained inhibitors, dilutions of the DNA extracts were tested for six sponge species representing five orders. The results suggested that the inhibitors were co-extracted with the sponge DNA, and a high dilution of this DNA was required for the successful PCR amplification for most of the samples. The optimized PCR conditions, including primer selection, PCR reaction system and program optimization, further improved the PCR performance. However, no single PCR condition was found to be suitable for the diverse sponge samples using various primer sets. These results highlight for the first time that the DNA extraction methods used are effective in obtaining actinobacterial DNA and that the presence of inhibitors in the sponge DNA requires high dilution coupled with fine tuning of the PCR conditions to achieve success in the study of sponge-associated actinobacterial diversity.
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  • 77
    Publikationsdatum: 2015-08-08
    Beschreibung: A search for heavy long-lived multi-charged particles is performed using the ATLAS detector at the LHC. Data collected in 2012 at \(\sqrt{s}=8\)  TeV from pp collisions corresponding to an integrated luminosity of 20.3 fb \(^{-1}\) are examined. Particles producing anomalously high ionisation, consistent with long-lived massive particles with electric charges from \(|q|=2e\) to \(|q|=6e\) are searched for. No signal candidate events are observed, and 95 % confidence level cross-section upper limits are interpreted as lower mass limits for a Drell–Yan production model. The mass limits range between 660 and 785 GeV.
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  • 78
    Publikationsdatum: 2015-08-08
    Beschreibung: Bacterial cell envelope is generally accepted as the primary target for a photo-induced oxidative stress. It is plausible that DNA damage occurs during the antimicrobial photoinactivation. Here we investigate the correlation between DNA damage and photoinactivation by evaluating the level of RecA-based DNA repair system in Staphylococcus aureus . By using exogenous photosensitizers (new methylene blue (NMB), toluidine blue O (TBO), 5,10,15,20-tetrakis(1-methyl-4-pyridinio)porphyrin tetra( p -toluenesulfonate) (TMPyP), zinc phthalocyanine (ZnPc), Rose Bengal (RB)) and ALA-induced endogenous porphyrin-dependent blue light (405 nm), several outcomes were observed: (i) an increase of DNA damage (from gel electrophoresis in DNA damage assay), (ii) an increase of recA expression (luminescence assay in recA - lux strain), and (iii) an increase of RecA protein level (Western blotting). When recA expression was repressed by novobiocin, or abolished by deleting the gene, S . aureus susceptibility towards photoinactivation was increased at approximately a hundred-fold. The absence of RecA increases DNA damage to yield bactericidal effect. In novobiocin-resistant mutant ( gyrB ), as opposed to wild type, neither RecA protein level nor cell’s susceptibility was affected by photoinactivation (when novobiocin is present). This is to suggest that GyrB-dependent inhibition mediated recA repression. Therefore, we have established the role of RecA in DNA damage during photoinactivation. With the use of rifampicin mutation frequency and Ames tests, we demonstrated that photoinactivation did not increase S . aureus mutagenesis and potentially is not mutagenic toward eukaryotic cells. The results suggest that the treatment is considered safe. In conclusion, we provide an evidence that recA inhibitor may serve as therapeutic adjuvant for antimicrobial photoinactivation. Clinical relevance of our findings warrants further investigations.
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  • 79
    Publikationsdatum: 2015-08-10
    Beschreibung: Calcitonin participates in controlling homeostasis of calcium and phosphorus and plays an important role in bone metabolism. The aim of this study was to endow an industrial strain of Saccharomyces cerevisiae with the ability to express chimeric human/salmon calcitonin (hsCT) without the use of antibiotics. To do so, a homologous recombination plasmid pUC18- rDNA2 - ura 3- P pgk - 5hsCT - rDNA1 was constructed, which contains two segments of ribosomal DNA of 1.1 kb ( rDNA1 ) and 1.4 kb ( rDNA2 ), to integrate the heterologous gene into host rDNA. A DNA fragment containing five copies of a chimeric human/salmon calcitonin gene ( 5hsCT ) under the control of the promoter for phosphoglycerate kinase ( P pgk ) was constructed to express 5hsCT in S. cerevisiae using ura 3 as a selectable auxotrophic marker gene. After digestion by restriction endonuclease Hpa I, a linear fragment, rDNA2 - ura 3- P pgk - 5hsCT - rDNA1 , was obtained and transformed into the △ ura3 mutant of S. cerevisiae by the lithium acetate method. The ura 3- P pgk - 5hsCT sequence was introduced into the genome at rDNA sites by homologous recombination, and the recombinant strain YS- 5hsCT was obtained. Southern blot analysis revealed that the 5hsCT had been integrated successfully into the genome of S. cerevisiae . The results of Western blot and ELISA confirmed that the 5hsCT protein had been expressed in the recombinant strain YS- 5hsCT . The expression level reached 2.04 % of total proteins. S. cerevisiae YS- 5hsCT decreased serum calcium in mice by oral administration and even 0.01 g lyophilized S. cerevisiae YS- 5hsCT /kg decreased serum calcium by 0.498 mM. This work has produced a commercial yeast strain potentially useful for the treatment of osteoporosis.
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  • 80
    Publikationsdatum: 2015-08-10
    Beschreibung: Since total petroleum hydrocarbons (TPH) are toxic and persistent in environments, studying the impact of oil contamination on microbial communities in different soils is vital to oil production engineering, effective soil management and pollution control. This study analyzed the impact of oil contamination on the structure, activity and function in carbon metabolism of microbial communities of Chernozem soil from Daqing oil field and Cinnamon soil from Huabei oil field through both culture-dependent techniques and a culture-independent technique—pyrosequencing. Results revealed that pristine microbial communities in these two soils presented disparate patterns, where Cinnamon soil showed higher abundance of alkane, (polycyclic aromatic hydrocarbons) PAHs and TPH degraders, number of cultivable microbes, bacterial richness, bacterial biodiversity, and stronger microbial activity and function in carbon metabolism than Chernozem soil. It suggested that complicated properties of microbes and soils resulted in the difference in soil microbial patterns. However, the changes of microbial communities caused by oil contamination were similar in respect of two dominant phenomena. Firstly, the microbial community structures were greatly changed, with higher abundance, higher bacterial biodiversity, occurrence of Candidate_division_BRC1 and TAO6 , disappearance of BD1-5 and Candidate_division_OD1 , dominance of Streptomyces , higher percentage of hydrocarbon-degrading groups, and lower percentage of nitrogen-transforming groups. Secondly, microbial activity and function in carbon metabolism were significantly enhanced. Based on the characteristics of microbial communities in the two soils, appropriate strategy for in situ bioremediation was provided for each oil field. This research underscored the usefulness of combination of culture-dependent techniques and next-generation sequencing techniques both to unravel the microbial patterns and understand the ecological impact of contamination.
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  • 81
    Publikationsdatum: 2015-08-10
    Beschreibung: Hydrogen is a promising alternative as an energetic carrier and its production by dark fermentation from wastewater has been recently proposed, with special attention to crude glycerol as potential substrate. In this study, two different feeding strategies were evaluated for replacing the glucose substrate by glycerol substrate: a one-step strategy (glucose was replaced abruptly by glycerol) and a step-by-step strategy (progressive decrease of glucose concentration and increase of glycerol concentration from 0 to 5 g L −1 ), in a continuous stirred tank reactor (12 h of hydraulic retention time (HRT), pH 5.5, 35 °C). While the one-step strategy led to biomass washout and unsuccessful H 2 production, the step-by-step strategy was efficient for biomass adaptation, reaching acceptable hydrogen yields (0.4 ± 0.1 mol H2  mol −1 glycerol consumed ) around 33 % of the theoretical yield independently of the glycerol concentration. Microbial community structure was investigated by single-strand conformation polymorphism (SSCP) and denaturing gradient gel electrophoresis (DGGE) fingerprinting techniques, targeting either the total community (16S ribosomal RNA (rRNA) gene) or the functional Clostridium population involved in H 2 production (hydA gene), as well as by 454 pyrosequencing of the total community. Multivariate analysis of fingerprinting and pyrosequencing results revealed the influence of the feeding strategy on the bacterial community structure and suggested the progressive structural adaptation of the community to increasing glycerol concentrations, through the emergence and selection of specific species, highly correlated to environmental parameters. Particularly, this work highlighted an interesting shift of dominant community members (putatively responsible of hydrogen production in the continuous stirred tank reactor (CSTR)) according to the gradient of glycerol proportion in the feed, from the family Veillonellaceae to the genera Prevotella and Clostridium sp., putatively responsible of hydrogen production in the CSTR.
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  • 82
    Publikationsdatum: 2015-08-14
    Beschreibung: Fucosyl- N -acetylglucosamine disaccharides are important core structures that form part of human mucosal and milk glyco-complexes. We have previously shown that AlfB and AlfC α-L-fucosidases from Lactobacillus casei are able to synthesize fucosyl-α-1,3-- N -acetylglucosamine (Fuc-α1,3-GlcNAc) and fucosyl-α-1,6- N -acetylglucosamine (Fuc-α1,6-GlcNAc), respectively, in transglycosylation reactions. Here, these reactions were performed in a semipreparative scale, and the produced disaccharides were purified. The maximum yields obtained of Fuc-α1,3-GlcNAc and Fuc-α1,6-GlcNAc were 4.2 and 9.3 g/l, respectively. The purified fucosyl-disaccharides were then analyzed for their prebiotic effect in vitro using strains from the Lactobacillus casei / paracasei / rhamnosus group and from Bifidobacterium species. The results revealed that 6 out of 11  L. casei strains and 2 out of 6  L. rhamnosus strains tested were able to ferment Fuc-α1,3-GlcNAc, and L. casei BL87 and L. rhamnosus BL327 strains were also able to ferment Fuc-α1,6-GlcNAc. DNA hybridization experiments suggested that the metabolism of Fuc-α1,3-GlcNAc in those strains relies in an α-L-fucosidase homologous to AlfB. Bifidobacterium breve and Bibidobacterium pseudocatenolatum species also metabolized Fuc-α1,3-GlcNAc. Notably, L-fucose was excreted from all the Lactobacillus and Bifidobacterium strains fermenting fucosyl-disaccharides, except from strains L. rhamnosus BL358 and BL377, indicating that in these latest strains, L-fucose was catabolized. The fucosyl-disaccharides were also tested for their inhibitory potential of pathogen adhesion to human colon adenocarcinoma epithelial (HT29) cell line. Enteropathogenic Escherichia coli (EPEC) strains isolated from infantile gastroenteritis were used, and the results showed that both fucosyl-disaccharides inhibited adhesion to different extents of certain EPEC strains to HT29 cells in tissue culture.
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  • 83
    Publikationsdatum: 2015-08-14
    Beschreibung: Gluconacetobacter xylinus (formerly Acetobacter xylinum and presently Komagataeibacter medellinensis ) is known to produce cellulose as a stable pellicle. However, it is also well known to lose this ability very easily. We investigated the on and off mechanisms of cellulose producibility in two independent cellulose-producing strains, R1 and R2. Both these strains were isolated through a repetitive static culture of a non-cellulose-producing K. medellinensis NBRC 3288 parental strain. Two cellulose synthase operons, types I and II, of this strain are truncated by the frameshift mutation in the bcsBI gene and transposon insertion in the bcsCII gene, respectively. The draft genome sequencing of R1 and R2 strains revealed that in both strains the bcsBI gene was restored by deletion of a nucleotide in its C-rich region. This result suggests that the mutations in the bcsBI gene are responsible for the on and off mechanism of cellulose producibility. When we looked at the genomic DNA sequences of other Komagataeibacter species, several non-cellulose-producing strains were found to contain similar defects in the type I and/or type II cellulose synthase operons. Furthermore, the phylogenetic relationship among cellulose synthase genes conserved in other bacterial species was analyzed. We observed that the cellulose genes in the Komagataeibacter shared sequence similarities with the γ-proteobacterial species but not with the α-proteobacteria and that the type I and type II operons could be diverged from a same ancestor in Komagataeibacter .
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  • 84
    Publikationsdatum: 2015-08-14
    Beschreibung: Currently, contamination of indoor environment by fungi and molds is considered as a public health problem. The monitoring of indoor airborne fungal contamination is a common tool to help understanding the link between fungi in houses and respiratory problems. Classical analytical monitoring methods, based on cultivation and microscopic identification, depend on the growth of the fungi. Consequently, they are biased by difficulties to grow some species on certain culture media and under certain conditions or by noncultivable or dead fungi that can consequently not be identified. However, they could have an impact on human health as they might be allergenic. Since molecular methods do not require a culture step, they seem an excellent alternative for the monitoring of indoor fungal contaminations. As a case study, we developed a SYBR® green real-time PCR-based assay for the specific detection and identification of Aspergillus versicolor , which is frequently observed in indoor environment and known to be allergenic. The developed primers amplify a short region of the internal transcribed spacer 1 from the 18S ribosomal DNA complex. Subsequently, the performance of this quantitative polymerase chain reaction (qPCR) method was assessed using specific criteria, including an evaluation of the selectivity, PCR efficiency, dynamic range, and repeatability. The limit of detection was determined to be 1 or 2 copies of genomic DNA of A. versicolor . In order to demonstrate that this SYBR® green qPCR assay is a valuable alternative for monitoring indoor fungal contamination with A. versicolor , environmental samples collected in contaminated houses were analyzed and the results were compared to the ones obtained with the traditional methods.
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  • 85
    Publikationsdatum: 2015-08-13
    Beschreibung: We study to which extent SUSY extensions of the Standard Model can describe the excess of events of 3.0 standard deviations observed by ATLAS in the on- Z signal region, respecting constraints by CMS on similar signal channels as well as constraints from searches for jets and \(E^\mathrm{miss}_\text {T}\) . GMSB-like scenarios are typically in conflict with these constraints, and do not reproduce well the shape of the \(E^\mathrm{miss}_\text {T}\) distribution of the data. An alternative scenario with two massive neutralinos can improve fits to the total number of events as well as to the \(H_\text {T}\) and \(E^\mathrm{miss}_\text {T}\) distributions. Such a scenario can be realised within the NMSSM.
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  • 86
    Publikationsdatum: 2015-08-13
    Beschreibung: Leading-twist operators have a remarkable property that their divergence vanishes in a free theory. Recently it was suggested that this property can be used for an alternative technique to calculate anomalous dimensions of leading-twist operators and allows one to gain one order in perturbation theory so that, i.e., two-loop anomalous dimensions can be calculated from one-loop Feynman diagrams, etc. In this work we study the feasibility of this program by a toy-model example of the \(\varphi ^3\) theory in six dimensions. Our conclusion is that this approach is valid, although it does not seem to present considerable technical simplifications as compared to the standard technique. It does provide one, however, with a very nontrivial check of the calculation as the structure of the contributions is very different.
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  • 87
    facet.materialart.
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    Springer
    Publikationsdatum: 2015-08-13
    Beschreibung: Recently, a family of interesting analytical brane solutions were found in f ( R ) gravity with \(f(R)=R \,+\, \alpha R^2\) in Bazeia et al. (Phys Lett B 729:127 2014 ). In these solutions, the inner brane structure can be turned on by tuning the value of the parameter \(\alpha \) . In this paper, we investigate how the parameter \(\alpha \) affects the localization and the quasilocalization of the tensorial gravitons around these solutions. It is found that, in a range of \(\alpha \) , despite the brane having an inner structure, there is no graviton resonance. However, in some other regions of the parameter space, although the brane has no internal structure, the effective potential for the graviton Kaluza–Klein (KK) modes has a singular structure, and there exist a series of graviton resonant modes. The contribution of the massive graviton KK modes to Newton’s law of gravity is discussed briefly.
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  • 88
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    Springer
    Publikationsdatum: 2015-08-13
    Beschreibung: The production of the Standard Model Higgs boson in association with a vector boson, followed by the dominant decay to \(H \rightarrow b\bar{b}\) , is a strong prospect for confirming and measuring the coupling to b -quarks in pp collisions at \(\sqrt{s}=14\)  TeV. We present an updated study of the prospects for this analysis, focussing on the most sensitive highly Lorentz-boosted region. The evolution of the efficiency and composition of the signal and main background processes as a function of the transverse momentum of the vector boson are studied covering the region 200–1000 GeV, comparing both a conventional dijet and jet substructure selection. The lower transverse momentum region (200–400 GeV) is identified as the most sensitive region for the Standard Model search, with higher transverse momentum regions not improving the statistical sensitivity. For much of the studied region (200–600 GeV), a conventional dijet selection performs as well as the substructure approach, while for the highest transverse momentum regions ( \(〉\) 600 GeV), which are particularly interesting for Beyond the Standard Model and high luminosity measurements, the jet substructure techniques are essential.
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  • 89
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    Springer
    Publikationsdatum: 2015-08-13
    Beschreibung: Massive QED, in contrast with its massless counterpart, possesses two conserved charges; one is a screened (vanishing) Maxwell charge which is directly associated with the massive vector mesons through the identically conserved Maxwell current, while the presence of a particle-antiparticle counting charge depends on the matter. A somewhat peculiar situation arises for couplings of Hermitian matter fields to massive vector potentials; in that case the only current is the screened Maxwell current and the coupling disappears in the massless limit. In the case of self-interacting massive vector mesons the situation becomes even more peculiar in that the usually renormalizability guaranteeing validity of the first order power-counting criterion breaks down in second order and requires the compensatory presence of additional Hermitian H -fields. Some aspect of these observation have already been noticed in the BRST gauge theoretic formulation, but here we use a new setting based on string-local vector mesons which is required by Hilbert space positivity (“off-shell unitarity”). This new formulation explains why spontaneous symmetry breaking cannot occur in the presence of higher spin \(s\ge 1\)  fields. The coupling to H -fields induces Mexican hat-like self-interactions; they are not imposed and bear no relation with spontaneous symmetry breaking; they are rather consequences of the foundational causal localization properties realized in a Hilbert space setting. In the case of self-interacting massive vector mesons their presence is required in order to maintain the first order power-counting restriction of renormalizability also in second order. The presentation of the new Hilbert space setting for vector mesons which replaces gauge theory and extends on-shell unitarity to its off-shell counterpart is the main motivation for this work. The new Hilbert space setting also shows that the second order Lie-algebra structure of self-interacting vector mesons is a consequence of the principles of QFT and promises a deeper understanding of the origin of confinement.
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  • 90
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    Springer
    Publikationsdatum: 2015-08-13
    Beschreibung: We develop a methodology for the construction of a Hessian representation of Monte Carlo sets of parton distributions, based on the use of a subset of the Monte Carlo PDF replicas as an unbiased linear basis, and of a genetic algorithm for the determination of the optimal basis. We validate the methodology by first showing that it faithfully reproduces a native Monte Carlo PDF set (NNPDF3.0), and then, that if applied to Hessian PDF set (MMHT14) which was transformed into a Monte Carlo set, it gives back the starting PDFs with minimal information loss. We then show that, when applied to a large Monte Carlo PDF set obtained as combination of several underlying sets, the methodology leads to a Hessian representation in terms of a rather smaller set of parameters (MC-H PDFs), thereby providing an alternative implementation of the recently suggested Meta-PDF idea and a Hessian version of the recently suggested PDF compression algorithm (CMC-PDFs). The mc2hessian conversion code is made publicly available together with (through LHAPDF6 ) a Hessian representations of the NNPDF3.0 set, and the MC-H PDF set.
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  • 91
    Publikationsdatum: 2015-08-13
    Beschreibung: We explore a fermionic dark matter model with a possible extension of Standard Model of particle physics into two Higgs doublet model. Higgs doublets couple to the singlet fermionic dark matter through a non-renormalisable coupling providing a new physics scale. We explore the viability of such dark matter candidate and constrain the model parameter space by collider serach, relic density of DM, direct detection measurements of DM-nucleon scattering cross-section and with the experimentally obtained results from indirect search of dark matter.
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  • 92
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    Springer
    Publikationsdatum: 2015-08-15
    Beschreibung: An overview of the flavour problem is presented, with emphasis on the theoretical efforts to find a satisfactory description of the fermion masses and the mixing angles.
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  • 93
    Publikationsdatum: 2015-08-10
    Beschreibung: Alphaproteobacterium strain Q-1 produces an extracellular multicopper oxidase (IOX), which catalyzes iodide (I – ) oxidation to form molecular iodine (I 2 ). In this study, the antimicrobial activity of the IOX/iodide system was determined. Both Gram-positive and Gram-negative bacteria tested were killed completely within 5 min by 50 mU mL –1 of IOX and 10 mM iodide. The sporicidal activity of the system was also tested and compared with a common iodophor, povidone-iodine (PVP-I). IOX (300 mU mL –1 ) killed Bacillus cereus , B. subtilis , and Geobacillus stearothermophilus spores with decimal reduction times of 2.58, 7.62, and 40.9 min, respectively. However, 0.1 % PVP-I killed these spores with much longer decimal reduction times of 5.46, 38.0, and 260 min, respectively. To evaluate the more superior sporicidal activity of the IOX system over PVP-I, the amount of free iodine (non-complexed I 2 ) was determined by an equilibrium dialysis technique. The IOX system included more than 40 mg L –1 of free iodine, while PVP-I included at most 25 mg L –1 free iodine. Our results suggest that the new enzyme-based antimicrobial system is effective against a wide variety of microorganisms and bacterial spores, and that its strong biocidal activity is due to its high free iodine content, which is probably maintained by re-oxidation of iodide released after oxidation of cell components by I 2 .
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    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
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  • 94
    Publikationsdatum: 2015-08-14
    Beschreibung: Many different organic compounds may be converted by microbial biotransformation to high-value products for the chemical and pharmaceutical industries. This review summarizes the use of strains of Aspergillus niger , a well-known filamentous fungus used in numerous biotechnological processes, for biochemical transformations of organic compounds. The substrates transformed include monocyclic, bicyclic, and polycyclic aromatic hydrocarbons; azaarenes, epoxides, chlorinated hydrocarbons, and other aliphatic and aromatic compounds. The types of reactions performed by A. niger , although not unique to this species, are extremely diverse. They include hydroxylation, oxidation of various functional groups, reduction of double bonds, demethylation, sulfation, epoxide hydrolysis, dechlorination, ring cleavage, and conjugation. Some of the products may be useful as new investigational drugs or chemical intermediates.
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  • 95
    Publikationsdatum: 2015-08-14
    Beschreibung: Nitrogen is an important nutrient in alcoholic fermentation because its starvation affects both fermentation kinetics and the formation of yeast metabolites. In most alcoholic fermentations, yeasts have to ferment in nitrogen-starved conditions, which requires modifications of cell functions to maintain a high sugar flux and enable cell survival for long periods in stressful conditions. In this review, we present an overview of our current understanding of the responses of the wine yeast Saccharomyces cerevisiae to variations of nitrogen availability. Adaptation to nitrogen starvation involves changes in the activity of signaling pathways such as target of rapamycin (TOR) and nitrogen catabolite repression (NCR), which are important for the remodeling of gene expression and the establishment of stress responses. Upon starvation, protein degradation pathways involving autophagy and the proteasome play a major role in nitrogen recycling and the adjustment of cellular activity. Recent progress in the understanding of the role of these mechanisms should enable advances in fermentation management and the design of novel targets for the selection or improvement of yeast strains.
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  • 96
    Publikationsdatum: 2015-08-14
    Beschreibung: Cell cultures often require the addition of animal serum and other supplements. In this study, silk sericin, a bioactive protein, recovered from the waste of silk floss production was hydrolysed into three pepsin-degraded sericin peptides with different ranges of molecular mass. Normal animal cells, tumour cells and hybridoma cells were cultured systematically in FBS culture media containing sericin as a supplement or serum substitute. The culture test and microscopic observation of L929 cells showed that the smaller molecular weight of the degraded sericin is most suitable for cell culture. The cell culture results showed that with the degradation of sericin, for normal mouse fibroblast L929 cells, addition of 0.75 % sericin into FBS culture medium yields cell viability that is superior to FBS culture medium alone. When all serum was replaced by sericin, cell viability in the sericin medium could reach about one half of that in FBS medium. When in a medium containing a mixture of FBS: sericin (6:4, v/v ), the cell culture effect is about 80 %. For the cultures of four tumour and one hybridoma cells, regardless of the molecular weight range, these degraded sericin peptides could substitute all serum in FBS media. The cell viability and proliferation of these tumour and hybridoma cells are equivalent or superior to that in FBS medium. In other words, cell viability and proliferation of these tumour and hybridoma cells in sericin media are more preferable to serum media. The mechanism of the sericin protein to promote cell growth and proliferation will be further investigated later.
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  • 97
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    Springer
    Publikationsdatum: 2015-08-14
    Beschreibung: Levansucrase catalyzes three distinct reactions depending on the fructosyl acceptor molecule, including polymerization, transfructosylation, and hydrolysis. As a key biocatalyst in the synthesis of levan and levan-type fructooligosaccharides, levansucrase has been widely and intensively studied. Due to the promising physiological effects of levan and levan-type fructooligosaccharides, they exhibit great potential in food and pharmaceutical industries. Another important point that attracts much attention is the wide substrate specificity of levansucrase toward monosaccharides, disaccharides, and aromatic and alkyl alcohols, producing diverse sucrose analogues, hetero-oligosaccharides (especially lactosucrose), and interesting fructosides. The present article summarizes and discusses the recent applications of microbial levansucrase in detail.
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  • 98
    Publikationsdatum: 2015-08-14
    Beschreibung: Hog lagoons can be major sources of waste and nutrient contamination to watersheds adjacent to pig farms. Fecal source tracking methods targeting Bacteroidetes 16S rRNA genes in pig fecal matter may underestimate or fail to detect hog lagoon contamination in riverine environments. In order to detect hog lagoon wastewater contamination in the Cape Fear Watershed, where a large number of hog farms are present, we conducted pyrosequencing analyses of Bacteroidetes 16S rRNA genes in hog lagoon waste and identified new hog lagoon-specific marker sequences. Additional pyrosequencing analyses of Bacteroidetes 16S rRNA genes were conducted with surface water samples collected at 4 sites during 5 months in the Cape Fear Watershed. Using an operational taxonomic unit (OTU) identity cutoff value of 97 %, these newly identified hog lagoon markers were found in 3 of the river samples, while only 1 sample contained the pig fecal marker. In the sample containing the pig fecal marker, there was a relatively high percentage (14.1 %) of the hog lagoon markers and a low pig fecal marker relative abundance of 0.4 % in the Bacteroidetes 16S rRNA gene sequences. This suggests that hog lagoon contamination must be somewhat significant in order for pig fecal markers to be detected, and low levels of hog lagoon contamination cannot be detected targeting only pig-specific fecal markers. Thus, new hog lagoon markers have a better detection capacity for lagoon waste contamination, and in conjunction with a pig fecal marker, provide a more comprehensive and accurate detection of hog lagoon waste contamination in susceptible watersheds.
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  • 99
    Publikationsdatum: 2015-08-14
    Beschreibung: Ginseng is one of the most important plants in oriental medicine. The pharmacological effects of this medicinal herb are mostly correlated to the major bioactive triterpene saponin, called ginsenoside. Due to the long cultivation period of ginseng and increased ginsenoside level in aged root, we need to develop strategies to increase ginseng productivity in cell and tissue culture in a faster way. Elicitation is already considered to improve the yield of this valuable secondary metabolite; especially, different types, timings, and durations of elicitation could affect the ginsenoside production and heterogeneity. Activation of ginsenoside biosynthetic genes and ginsenoside accumulation mediated by elicitor-induced signaling molecules would be helpful for commercial production of individual ginsenosides. Jasmonic acid is the well-known signaling molecule which mainly involved in ginsenoside accumulation. Ca 2+ spiking and reactive oxygen species, nitric oxide, and ethylene production are other messengers which mediate production of ginsenoside. This review highlights the elicitation strategies for production of the ginsenoside based on the principle of putative signal transduction pathways.
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  • 100
    Publikationsdatum: 2015-09-16
    Beschreibung: The production of the massive bosons \(Z^0\) and \(W^{\pm }\) could provide an excellent tool to study cold nuclear matter effects and the modifications of nuclear parton distribution functions (nPDFs) relative to the parton distribution functions (PDFs) of a free proton in high-energy nuclear reactions at the LHC as well as in heavy-ion collisions (HIC) with much higher center-of-mass energies available in the future colliders. In this paper we calculate the rapidity and transverse momentum distributions of the vector boson and their nuclear modification factors in p + Pb collisions at \(\sqrt{s_{NN}}=63\)  TeV and in Pb + Pb collisions at \(\sqrt{s_{NN}}=39\)  TeV in the framework of perturbative QCD by utilizing three parametrization sets of nPDFs: EPS09, DSSZ, and nCTEQ. It is found that in heavy-ion collisions at such high colliding energies, both the rapidity distribution and the transverse momentum spectrum of vector bosons are considerably suppressed in wide kinematic regions with respect to p + p reactions due to large nuclear shadowing effect. We demonstrate that the massive vector boson production processes with sea quarks in the initial state may give more contributions than those with valence quarks in the initial state; therefore in future heavy-ion collisions the isospin effect is less pronounced and the charge asymmetry of the W boson will be reduced significantly as compared to that at the LHC. A large difference between results with nCTEQ and results with EPS09 and DSSZ is observed in nuclear modifications of both rapidity and \(p_T\) distributions of \(Z^0\) and W in the future HIC.
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