bluuebunny/crossref_metadata_2025 huggingface dataset:
Correct folding of an α-helix and a β-hairpin using a polarized 2D torsional potential
Authors: Gao Ya , Li Yongxiu , Mou Lirong , Lin Bingbing , Zhang John Z. H. , Mei Ye
Published: June 2015

A new modification to the AMBER force field that incorporates the coupled two-dimensional main chain torsion energy has been evaluated for the balanced representation of secondary structures. In this modified AMBER force field (AMBER032D), the main chain torsion energy is represented by 2-dimensional Fourier expansions with parameters fitted to the potential energy surface generated by high-level quantum mechanical calculations of small peptides in solution. Molecular dynamics simulations are performed to study the folding of two model peptides adopting either α-helix or β-hairpin structures. Both peptides are successfully folded into their native structures using an AMBER032D force field with the implementation of a polarization scheme (AMBER032Dp). For comparison, simulations using a standard AMBER03 force field with and without polarization, as well as AMBER032D without polarization, fail to fold both peptides successfully. The correction to secondary structure propensity in the AMBER03 force field and the polarization effect are critical to folding Trpzip2; without these factors, a helical structure is obtained. This study strongly suggests that this new force field is capable of providing a more balanced preference for helical and extended conformations. The electrostatic polarization effect is shown to be indispensable to the growth of secondary structures.
Single-Molecule Imaging Reveals Dynamics of CREB Transcription Factor Bound to Its Target Sequence
Authors: Sugo Noriyuki , Morimatsu Masatoshi , Arai Yoshiyuki , Kousoku Yoshinori , Ohkuni Aya , Nomura Taishin , Yanagida Toshio , Yamamoto Nobuhiko
Published: June 2015

Proper spatiotemporal gene expression is achieved by selective DNA binding of transcription factors in the genome. The most intriguing question is how dynamic interactions between transcription factors and their target sites contribute to gene regulation by recruiting the basal transcriptional machinery. Here we demonstrate individual binding and dissociation events of the transcription factor cAMP response element-binding protein (CREB), both in vitro and in living cells, using single-molecule imaging. Fluorescent–tagged CREB bound to its target sequence cAMP-response element (CRE) for a remarkably longer period (dissociation rate constant: 0.21 s-1) than to an unrelated sequence (2.74 s-1). Moreover, CREB resided at restricted positions in the living cell nucleus for a comparable period. These results suggest that CREB stimulates transcription by binding transiently to CRE in the time range of several seconds.
In silico identification of AMPylating enzymes and study of their divergent evolution
Authors: Khater Shradha , Mohanty Debasisa
Published: June 2015

AMPylation is a novel post-translational modification (PTM) involving covalent attachment of an AMP moiety to threonine/tyrosine side chains of a protein. AMPylating enzymes belonging to three different families, namely Fic/Doc, GS-ATase and DrrA have been experimentally characterized. Involvement of these novel enzymes in a myriad of biological processes makes them interesting candidates for genome-wide search. We have used SVM and HMM to develop a computational protocol for identification of AMPylation domains and their classification into various functional subfamilies catalyzing AMPylation, deAMPylation, phosphorylation and phosphocholine transfer. Our analysis has not only identified novel PTM catalyzing enzymes among unannotated proteins, but has also revealed how this novel enzyme family has evolved to generate functional diversity by subtle changes in sequence/structures of the proteins. Phylogenetic analysis of Fic/Doc has revealed three new isofunctional subfamilies, thus adding to their functional divergence. Also, frequent occurrence of Fic/Doc proteins on highly mobile and unstable genomic islands indicated their evolution via extensive horizontal gene transfers. On the other hand phylogenetic analyses indicate lateral evolution of GS-ATase family and an early duplication event responsible for AMPylation and deAMPylation activity of GS-ATase. Our analysis also reveals molecular basis of substrate specificity of DrrA proteins.
Melanophilin Stimulates Myosin-5a Motor Function by Allosterically Inhibiting the Interaction between the Head and Tail of Myosin-5a
Authors: Yao Lin-Lin , Cao Qing-Juan , Zhang Hai-Man , Zhang Jie , Cao Yang , Li Xiang-dong
Published: June 2015

The tail-inhibition model is generally accepted for the regulation of myosin-5a motor function. Inhibited myosin-5a is in a folded conformation in which its globular tail domain (GTD) interacts with its head and inhibits its motor function and high Ca2+ or cargo binding may reduce the interaction between the GTD and the head of myosin-5a, thus activating motor activity. Although it is well established that myosin-5a motor function is regulated by Ca2+, little is known about the effects of cargo binding. We previously reported that melanophilin (Mlph), a myosin-5a cargo-binding protein, is capable of activating myosin-5a motor function. Here, we report that Mlph-GTBDP, a 26 amino-acid-long peptide of Mlph, is sufficient for activating myosin-5a motor function. We demonstrate that Mlph-GTBDP abolishes the interaction between the head and GTD of myosin-5a, thereby inducing a folded-to-extended conformation transition for myosin-5a and activating its motor function. Mutagenesis of the GTD shows that the GTD uses two distinct, non-overlapping regions to interact with Mlph-GTBDP and the head of myosin-5a. We propose that the GTD is an allosteric protein and that Mlph allosterically inhibits the interaction between the GTD and head of myosin-5a, thereby activating myosin-5a motor function.
Surface Mn(II) oxidation actuated by a multicopper oxidase in a soil bacterium leads to the formation of manganese oxide minerals
Authors: Zhang Zhen , Zhang Zhongming , Chen Hong , Liu Jin , Liu Chang , Ni Hong , Zhao Changsong , Ali Muhammad , Liu Fan , Li Lin
Published: June 2015

In this manuscript, we report that a bacterial multicopper oxidase (MCO266) catalyzes Mn(II) oxidation on the cell surface, resulting in the surface deposition of Mn(III) and Mn(IV) oxides and the gradual formation of bulky oxide aggregates. These aggregates serve as nucleation centers for the formation of Mn oxide micronodules and Mn-rich sediments. A soil-borne Escherichia coli with high Mn(II)-oxidizing activity formed Mn(III)/Mn(IV) oxide deposit layers and aggregates under laboratory culture conditions. We engineered MCO266 onto the cell surfaces of both an activity-negative recipient and wild-type strains. The results confirmed that MCO266 governs Mn(II) oxidation and initiates the formation of deposits and aggregates. By contrast, a cell-free substrate, heat-killed strains and intracellularly expressed or purified MCO266 failed to catalyze Mn(II) oxidation. However, purified MCO266 exhibited Mn(II)-oxidizing activity when combined with cell outer membrane component (COMC) fractions in vitro. We demonstrated that Mn(II) oxidation and aggregate formation occurred through an oxygen-dependent biotic transformation process that requires a certain minimum Mn(II) concentration. We propose an approximate electron transfer pathway in which MCO266 transfers only one electron to convert Mn(II) to Mn(III) and then cooperates with other COMC electron transporters to transfer the other electron required to oxidize Mn(III) to Mn(IV).
Aptamer-based Sandwich Assay and its Clinical Outlooks for Detecting Lipocalin-2 in Hepatocellular Carcinoma (HCC)
Authors: Lee Kyeong-Ah , Ahn Ji-Young , Lee Sang-Hee , Singh Sekhon Simranjeet , Kim Dae-Ghon , Min Jiho , Kim Yang-Hoon
Published: June 2015

We validated a single-stranded, DNA aptamer-based, diagnostic method capable of detecting Lipocalin-2 (LCN2), a biomarker from clinically relevant hepatocellular carcinoma (HCC) patient serum, in the sandwich assay format. Nine aptamers (LCN2_apta1 to LCN2_apta9) for LCN2 were screened with SELEX processes and a sandwich pair (LCN2_apta2 and LCN2_apta4) was finally chosen using surface plasmon resonance (SPR) and dot blotting analysis. The result of the proposed aptamer sandwich construction shows that LCN2 was sensitively detected in the concentration range of 2.5–500 ng mL−1 with a limit of detection of 0.6 ng mL−1. Quantitative measurement tests in HCC patients were run on straight serum and were compared with the performance of the conventional antibody-based ELISA kit. The aptamer sandwich assay demonstrated an excellent dynamic range for LCN2 at clinically relevant serum levels, covering sub-nanogram per mL concentrations. The new approach offers a simple and robust method for detecting serum biomarkers that have low and moderate abundance. It consists of functionalization, hybridization and signal read-out and no dilution is required. The results of the study demonstrate the capability of the aptamer sandwich assay platform for diagnosing HCC and its potential applicability to the point-of-care testing (POCT) system.
Molecular and structural analysis of Legionella DotI gives insights into an inner membrane complex essential for type IV secretion
Authors: Kuroda Takuya , Kubori Tomoko , Thanh Bui Xuan , Hyakutake Akihiro , Uchida Yumiko , Imada Katsumi , Nagai Hiroki
Published: June 2015

The human pathogen Legionella pneumophila delivers a large array of the effector proteins into host cells using the Dot/Icm type IVB secretion system. Among the proteins composing the Dot/Icm system, an inner membrane protein DotI is known to be crucial for the secretion function but its structure and role in type IV secretion had not been elucidated. We report here the crystal structures of the periplasmic domains of DotI and its ortholog in the conjugation system of plasmid R64, TraM. These structures reveal a striking similarity to VirB8, a component of type IVA secretion systems, suggesting that DotI/TraM is the type IVB counterpart of VirB8. We further show that DotI and its partial paralog DotJ form a stable heterocomplex. R64 TraM, encoded by the conjugative plasmid lacking DotJ ortholog, forms a homo-hexamer. The DotI-DotJ complex is distinct from the core complex, which spans both inner and outer membranes to form a substrate conduit and seems not to stably associate with the core complex. These results give insight into VirB8-family inner membrane proteins essential for type IV secretion and aid towards understanding the molecular basis of secretion systems essential for bacterial pathogenesis.
Nodal bilayer-splitting controlled by spin-orbit interactions in underdoped high-Tc cuprates
Authors: Harrison N. , Ramshaw B. J. , Shekhter A.
Published: June 2015

The highest superconducting transition temperatures in the cuprates are achieved in bilayer and trilayer systems, highlighting the importance of interlayer interactions for high Tc. It has been argued that interlayer hybridization vanishes along the nodal directions by way of a specific pattern of orbital overlap. Recent quantum oscillation measurements in bilayer cuprates have provided evidence for a residual bilayer-splitting at the nodes that is sufficiently small to enable magnetic breakdown tunneling at the nodes. Here we show that several key features of the experimental data can be understood in terms of weak spin-orbit interactions naturally present in bilayer systems, whose primary effect is to cause the magnetic breakdown to be accompanied by a spin flip. These features can now be understood to include the equidistant set of three quantum oscillation frequencies, the asymmetry of the quantum oscillation amplitudes in c-axis transport compared to ab-plane transport and the anomalous magnetic field angle dependence of the amplitude of the side frequencies suggestive of small effective g-factors. We suggest that spin-orbit interactions in bilayer systems can further affect the structure of the nodal quasiparticle spectrum in the superconducting phase. PACS numbers: 71.45.Lr, 71.20.Ps, 71.18.+y
Solid-state Reaction of Azolium Hydrohalogen Salts with Silver Dicyanamide – Unexpected Formation of Cyanoguanidine-azoles, Reaction Mechanism and Their Hypergolic Properties
Authors: Liu Wei , Lin Qiu-han , Li Yu-chuan , Chen Peng-wan , Fang Tao , Zhang Ru-bo , Pang Si-ping
Published: June 2015

Cyanoguanidines as well as azoles are important bioactive groups, which play an important role in the medical application; meanwhile, the high nitrogen content makes them excellent backbones for energetic materials. A Novel and simple method that combined these two fragments into one molecular compound was developed through the transformation of dicyanamide ionic salts. In return, compounds 4–11 were synthesized and fully characterized by IR, MS, NMR and elemental analysis. Meanwhile, the structures of compounds 4, 8 and 11 were confirmed by X-ray crystal diffraction. Detailed reaction mechanisms were studied through accurate calculations on the reaction energy profiles of the azolium cations and DCA anion, which revealed the essence of the transformation proceeding. Meanwhile, compound 8 exhibits excellent hypergolic property, which could be potentially novel molecular hypergolic fuel.
Three-dimensional patterns from the thin-film drying of amino acid solutions
Authors: Zhang Xuehua , Crivoi Alexandru , Duan Fei
Published: June 2015

Experimental atomic force microscopy (AFM) images show the dried-in patterns from amino acid solutions which can be in the form of dots or networks. The three-dimensional lattice-gas Kinetic Monte Carlo (KMC) model is applied to simulate the formation of dot-like and network-like particle structures from the evaporating thin films of solutions. A sigmoidal jump in the chemical potential value is implemented to obtain dual-scale structures with the grain size distribution peaking at two distinctive values. The simulated and experimental results are qualitatively comparable.
Mechanisms linking metabolism of Helicobacter pylori to 18O and 13C-isotopes of human breath CO2
Authors: Som Suman , De Anulekha , Banik Gourab Dutta , Maity Abhijit , Ghosh Chiranjit , Pal Mithun , Daschakraborty Sunil B. , Chaudhuri Sujit , Jana Subhra , Pradhan Manik
Published: June 2015

The gastric pathogen Helicobacter pylori utilize glucose during metabolism, but the underlying mechanisms linking to oxygen-18 (18O) and carbon-13 (13C)-isotopic fractionations of breath CO2 during glucose metabolism are poorly understood. Using the excretion dynamics of 18O/16O and 13C/12C-isotope ratios of breath CO2, we found that individuals with Helicobacter pylori infections exhibited significantly higher isotopic enrichments of 18O in breath CO2 during the 2h-glucose metabolism regardless of the isotopic nature of the substrate, while no significant enrichments of 18O in breath CO2 were manifested in individuals without the infections. In contrast, the 13C-isotopic enrichments of breath CO2 were significantly higher in individuals with Helicobacter pylori compared to individuals without infections in response to 13C-enriched glucose uptake, whereas a distinguishable change of breath 13C/12C-isotope ratios was also evident when Helicobacter pylori utilize natural glucose. Moreover, monitoring the 18O and 13C-isotopic exchange in breath CO2 successfully diagnosed the eradications of Helicobacter pylori infections following a standard therapy. Our findings suggest that breath 12C18O16O and 13C16O16O can be used as potential molecular biomarkers to distinctively track the pathogenesis of Helicobacter pylori and also for eradication purposes and thus may open new perspectives into the pathogen’s physiology along with isotope-specific non-invasive diagnosis of the infection.
Quantifying of total volatile basic nitrogen (TVB-N) content in chicken using a colorimetric sensor array and nonlinear regression tool
Authors: Urmila Khulal , Li Huanhuan , Chen Quansheng , Hui Zhe , Zhao Jiewen
Published: June 2015

Total volatile basic nitrogen (TVB-N) content is an important indicator for evaluating meat's freshness.
Trace determination of five organophosphorus pesticides by using QuEChERS coupled with dispersive liquid–liquid microextraction and stacking before micellar electrokinetic chromatography
Authors: Wei Jinchao , Cao Jiliang , Tian Ke , Hu Yuanjia , Su Huanxing , Wan Jianbo , Li Peng
Published: June 2015

The proposed method offers an ideal solution for the determination of trace pesticides in real samples with complex matrices.
Practical catalytic method for synthesis of sterically hindered anilines
Authors: Mailig Melrose , Rucker Richard P. , Lalic Gojko
Published: June 2015

Synthesis of sterically hindered 1° and 2° anilines from arylboronic esters is accomplished using air-stable and commercially available catalyst precursors.
Bis(4-pyridyl)mercury – a new linear tecton in crystal engineering: coordination polymers and co-crystallization processes
Authors: Mocanu Teodora , Raţ Ciprian I. , Maxim Catalin , Shova Sergiu , Tudor Violeta , Silvestru Cristian , Andruh Marius
Published: June 2015

Three new coordination polymers have been obtained using bis(4-pyridyl)mercury (py2Hg) as a spacer: [Cu(Hmea)2(py2Hg)](ClO4)2·2(py2Hg) (1), [Cu2(pa)2(py2Hg)(ClO4)2]·0.5(py2Hg)·H2O (2), and [Cu2(pa)2(py2Hg)2](BF4)2 (3) (Hmea = monoethanolamine; Hpa = propanolamine).
Surface-enhanced Raman scattering behaviour of 4-mercaptophenyl boronic acid on assembled silver nanoparticles
Authors: Li Shuangshuang , Zhou Qun , Chu Wenya , Zhao Wei , Zheng Junwei
Published: June 2015

SERS properties of 4-mercaptophenylboronic acid (4-MPBA) on AgNPs were studied systematically; a self-condensation reaction of 4-MPBA, competitor of the binding of glucose, was found to preferentially happen at higher pH values.
On the development of a facile approach based on the use of ionic liquids: preparation of PLLA (sc-PLA)/high surface area nano-graphite systems
Authors: Gardella Lorenza , Furfaro Davide , Galimberti Maurizio , Monticelli Orietta
Published: June 2015

A method to prepare composite systems based on polylactide and high surface area nano-graphite has been developed, consisting of the application of ionic liquids as dispersing/exfoliating agents for nanofillers.
Preparation of silver nanoparticles embedded hierarchically porous AlPO4 monoliths
Authors: Cai Xiaobo , Zhu Wenjun , Yang Hui , Xu Chenyang , Nakanishi Kazuki , Kanamori Kazuyoshi , Guo Xingzhong
Published: June 2015

Silver nanoparticles were homogenously embedded on the skeletons of hierarchically porous AlPO4 by immersing the monoliths in a silver colloid.
Efficient synthetic supramolecular channels and their light-deactivated ion transport in bilayer lipid membranes
Authors: Bao Chunyan , Ma Meixin , Meng Funa , Lin Qiuning , Zhu Linyong
Published: June 2015

Efficient ion transport and photo-deactivation was achieved from the self-assembled channel of o-nitrobenzyl-based amphiphilic small molecules.
Drift-corrected nanoplasmonic hydrogen sensing by polarization
Authors: Wadell Carl , Langhammer Christoph
Published: June 2015

Accurate and reliable hydrogen sensors are an important enabling technology for the large-scale introduction of hydrogen as a fuel or energy storage medium. To enable the long-term use of plasmonic sensors in this particular context, we introduce a concept for drift-correction based on light polarization utilizing symmetric sensor and sensing material nanoparticles arranged in a heterodimer.
Monitoring patterned enzymatic polymerization on DNA origami at single-molecule level
Authors: Okholm A. H. , Aslan H. , Besenbacher F. , Dong M. , Kjems J.
Published: June 2015

Site-selective enzymatic polymerization by TdT on surface-bound DNA origami embedded in BSA. DNA polymerization was visualized real time by AFM.
One-pot synthesis of high-index faceted AgCl nanocrystals with trapezohedral, concave hexoctahedral structures and their photocatalytic activity
Authors: Zhang Haibin , Lu Yonggang , Liu Hong , Fang Jingzhong
Published: June 2015

The one-pot solvothermal synthesis of AgCl semiconductor nanocrystals with high-index faceted trapezohedral and concave hexoctahedral structures is reported for the first time.
Facile construction of fluorescent polymeric aggregates with various morphologies by self-assembly of supramolecular amphiphilic graft copolymers
Authors: Ji Xiaofan , Li Yang , Wang Hu , Zhao Run , Tang Guping , Huang Feihe
Published: June 2015

Facile construction of fluorescent polymeric aggregates with various morphologies was realized by self-assembly of supramolecular amphiphilic graft copolymers.
Catalytic enantioselective synthesis of quaternary 3,3′-indolyloxindoles by combination of Rh(ii) complexes and chiral phosphines
Authors: Chen Dian-Feng , Zhang Chen-long , Hu Yue , Han Zhi-Yong , Gong Liu-Zhu
Published: June 2015

Rh(ii)/chiral phosphine combined catalysis has been developed for a highly efficient sequential C–H functionalization/asymmetric allylation or Michael addition reaction to afford a diverse range of quaternary 3,3′-indolyloxindole derivatives.
Highly flexible and conductive composite films of silk fibroin and silver nanowires for optoelectronic devices
Authors: Qi Ning , Zhao Bing , Wang Shu-Dong , Al-Deyab Salem S. , Zhang Ke-Qin
Published: June 2015

Silver nanowire-coated silk fibroin composite films assisted by ion sputtering exhibited excellent flexibility, conductivity, which used to light LED device.
Quantum molecular modelling of ibuprofen bound to human serum albumin
Authors: Dantas Diego S. , Oliveira Jonas I. N. , Lima Neto José X. , da Costa Roner F. , Bezerra Eveline M. , Freire Valder N. , Caetano Ewerton W. S. , Fulco Umberto L. , Albuquerque Eudenilson L.
Published: June 2015

The total interaction energies of the ibuprofen complexed with FA3/FA4 and FA6 binding sites of human serum albumin are in agreement with the hypothesis that the Sudlow's site II is the main binding pocket for ibuprofen.
Hydrophilic molecularly imprinted microspheres functionalized with amino and carboxyl groups for highly selective recognition of human hemoglobin in aqueous solution
Authors: Lai Jia-Ping , Zuo Yue , Sun Hui , Yu Ying
Published: June 2015

HMIMs functionalized with amino and carboxyl groups were synthesized for HHb. The HMIMs exhibit selective recognition properties toward the target protein. QCM results demonstrate the HMIMs coated electrode shows a more sensitive response to HHb than the NIMs coated one.
High-performance dye-sensitized solar cell based on an electrospun poly(vinylidene fluoride-co-hexafluoropropylene)/cobalt sulfide nanocomposite membrane electrolyte
Authors: Vijayakumar E. , Subramania A. , Fei Zhaofu , Dyson Paul J.
Published: June 2015

Electrospun PVdF-HFP/CoS (1 wt%) nanocomposite membrane prepared by electrospinning technique.
Boron and phosphorous-doped graphene as a metal-free electrocatalyst for the oxygen reduction reaction in alkaline medium
Authors: Jo Gayoung , Sanetuntikul Jakkid , Shanmugam Sangaraju
Published: June 2015

Phosphorous and boron-doped graphene, prepared using a single precursor, showed reasonable oxygen reduction activity and excellent stability in alkaline electrolyte.
Improving the SERS detection sensitivity of aromatic molecules by a PDMS-coated Au nanoparticle monolayer film
Authors: Qian Chen , Guo Qinghua , Xu Minmin , Yuan Yaxian , Yao Jianlin
Published: June 2015

In this paper, we reported a facile strategy to fabricate a PDMS film-coated Au nanoparticle monolayer film (Au MLF) composite substrate for improving SERS detection of aromatic molecules in water and in the atmosphere.
Magnetoplasmons in simple hexagonal graphite
Authors: Chen Rong-Bin , Chiu Chih-Wei , Lin Ming-Fa
Published: June 2015

Magneto-electronic Coulomb excitations in simple hexagonal graphite (SHG) are studied within the randomphase approximation.
Vitamin E TPGS based nanogel for the skin targeting of high molecular weight anti-fungal drug: development and in vitro and in vivo assessment
Authors: Kaur Lakhvir , Jain Subheet Kumar , Singh Kanwaldeep
Published: June 2015

Enhanced skin permeation and deposition potential of nanogel containing Vitamin E TPGS.
Potent and selective inhibition of SH3 domains with dirhodium metalloinhibitors
Authors: Vohidov Farrukh , Knudsen Sarah E. , Leonard Paul G. , Ohata Jun , Wheadon Michael J. , Popp Brian V. , Ladbury John E. , Ball Zachary T.
Published: June 2015

Specific, designed histidine–rhodium interactions allow a metallopeptide to bind Lyn kinase with nanomolar affinity and to activate kinase activity.
The shape effect of TiO2 in VOx/TiO2 catalysts for selective reduction of NO by NH3
Authors: Shi Quanquan , Li Yong , Zhou Yan , Miao Shu , Ta Na , Zhan Ensheng , Liu Jingyue (Jimmy) , Shen Wenjie
Published: June 2015

Octahedral vanadia species on TiO2 {001} showed a significantly higher activity for selective reduction of NO by NH3 than tetrahedral vanadia species on TiO2 {101}.
Thermally tunable circular dichroism and circularly polarized luminescence of tetraphenylethene with two cholesterol pendants
Authors: Ye Qiang , Zhu Dandan , Zhang Hongxing , Lu Xuemin , Lu Qinghua
Published: June 2015

A novel cholesteric liquid crystal molecule 2CTPE with thermally tunable CPL properties based on cholesterol and tetraphenylethylene was successfully synthesized.
The molecular picture of amplified spontaneous emission of star-shaped functionalized-truxene derivatives
Authors: Ma Lin , Wu Zhaoxin , Zhou Guijiang , Yuan Fang , Yu Yue , Yao Chunliang , Ning Shuya , Hou Xun , Li Yu , Wang Shufeng , Gong Qihuang
Published: June 2015

Organic optical gain materials are the basis for organic solid-state lasers.
Colour laser printer identification using halftone texture fingerprint
Authors: Kim Do‐Guk , Lee Heung‐Kyu
Published: June 2015

Numerous forgeries are made by precise and fast colour laser printers, and they have the ability to cause severe harm to society. To prevent such forgeries, printer identification can be employed as a countermeasure. A new method is presented to identify colour laser printers using halftone texture fingerprints. The method uses images photographed without an additional close‐up lens as input images, and halftone texture fingerprints are extracted in the curvelet transform domain. The extracted halftone texture fingerprint is used in correlation‐based detection, and the colour laser printer of the most similar known halftone texture fingerprint is determined as the source colour laser printer. Experiments are performed on five colour laser printers and the performance is compared with existing methods. Experimental results show that the method overcomes the limitations of existing methods.
Short‐circuit protection of LLC resonant converter using voltages across resonant tank elements
Authors: Zaikin Denys Igorovych
Published: June 2015

This paper describes two methods for the short‐circuit protection of the LLC resonant converter. One of them uses the voltage across the capacitor and the other uses the voltage across the inductor of the resonant tank. These voltages can be processed (integrated or differentiated) to recover the resonant tank current. The two circuits illustrated in the described methods make it possible to develop a robust LLC converter design and to avoid using lossy current measurement elements, such as a shunt resistor or current transformer. The methods also allow measuring resonant tank current without breaking high‐current paths and connecting the measuring circuit in parallel with the inductor or capacitor of the resonant tank. Practical implementations of these indirect current measurements have been experimentally tested for the short‐circuit protection of the 1600 W LLC converter.
Selectable marker-free co-expression of Nicotiana rustica CN and Nicotiana tabacum HAK1 genes improves resistance to tobacco mosaic virus in tobacco
Authors: Qin Li-Jun , Zhao Dan , Zhang Yi , Zhao De-Gang
Published: June 2015

The viral disease caused by tobacco mosaic virus (TMV) is the most prevalent viral disease in many tobacco production areas. A breeding strategy based on resistance genes is an effective method for improving TMV resistance in tobacco. Also, the physiological status of plants is also critical to disease resistance improvement. Potassium ion is one of the most abundant inorganic nutrients in plant cells, and mediates plant responses to abiotic and biotic stresses. Improving K+ content in soil by fertilising can enhance diseases resistance of crops. However, the K+ absorption in plants depends mostly on K+ transporters located in cytoplasmic membrane. Therefore, the encoding genes for K+ transporters are putative candidates to target for improving tobacco mosaic virus resistance. In this work, the synergistic effect of a N-like resistance gene CN and a tobacco putative potassium transporter gene HAK1 was studied. The results showed that TMV-resistance in CN-HAK1-containing tobaccos was significantly enhanced though a of strengthening leaf thickness and reduction in the size of necrotic spots compared with only CN-containing plants, indicating the improvement of potassium nutrition in plant cells could increase the tobacco resistance to TMV by reducing the spread of the virus. Quantitative real-time polymerase chain reaction (qRT–PCR) analysis for TMV-CP expression in the inoculated leaf of the transgenic and wild-type plants also supported the conclusion. Further, the results of defence-related determination including antioxidative enzymes (AOEs) activity, salicylic acid (SA) content and the expression of resistance-related genes demonstrated CN with HAK1 synergistically enhanced TMV-resistance in transgenic tobaccos. Additionally, the HAK1- overexpression significantly improved the photosynthesis and K+-enriching ability in trans-CN-HAK1 tobaccos, compared with other counterparts. Finally, this work provides a method for screening new varieties of marker-free and safe transgenic antiviral tobacco.
Evolutionary and phenotypic analysis of live virus isolates suggests arthropod origin of a pathogenic RNA virus family
Authors: Marklewitz Marco , Zirkel Florian , Kurth Andreas , Drosten Christian , Junglen Sandra
Published: June 2015

Significance

Knowledge of the origin and evolution of viruses provides important insight into virus emergence involving the acquisition of genes necessary for the infection of new host species or the development of pathogenicity. The family
Bunyaviridae
contains important arthropod-borne pathogens of humans, animals, and plants. In this study, we provide a comprehensive characterization of two novel lineages of insect-specific bunyaviruses that are in basal phylogenetic relationship to the rodent-borne hantaviruses, the only genus within the
Bunyaviridae
that is not transmitted by arthropod vectors. These data, together with ancestral state reconstruction of bunyavirus hosts for major virus lineage bifurcations, suggest that the vertebrate-infecting viruses evolved from arthropod-specific progenitors.
Extrachromosomal circular DNA is common in yeast
Authors: Møller Henrik D. , Parsons Lance , Jørgensen Tue S. , Botstein David , Regenberg Birgitte
Published: June 2015

Significance

We performed a screen for extrachromosomal circular DNAs containing segments of genomic yeast DNA. We found 1,756 such extrachromosomal circular DNAs containing about 23% of the total yeast genomic information. The abundance of these circular forms of genomic DNA suggests that eccDNA formation might be a common mutation that can arise in any part of the genome, and not in only a few special loci. We propose that eccDNAs may be precursors to the copy number variation in eukaryotic genomes characteristic of both the evolutionary process and cancer progression.
Effect of Predator Size and Prey Characteristics on Piscivory of Juvenile Largemouth Bass
Authors: Einfalt Lisa M. , Parkos Joseph J. , Wahl David H.
Published: June 2015

Largemouth Bass Micropterus salmoides undergo a diet shift to fish prey during the juvenile stage, but mechanisms influencing piscivorous behavior are largely unknown. In laboratory experiments, we examined ontogenetic effects of predator and prey size on piscivory of juvenile Largemouth Bass. Prey size preferences were determined in aquaria experiments by introducing multiple size ranges of either Bluegill Lepomis macrochirus, Gizzard Shad Dorosoma cepedianum, or Fathead Minnow Pimephales promelas with a Largemouth Bass from one of three length‐classes (30, 50, and 75 mm TL). For Gizzard Shad, Largemouth Bass most often selected larger sizes (33–65% of Largemouth Bass length) than in experiments with either Fathead Minnow or Bluegill (25–48%). Although an optimal foraging model (handling time/prey dry mass) predicted most prey sizes chosen, Largemouth Bass, with their large gape, chose slightly larger prey than predicted for all three prey species. Using optimal‐sized prey, we further investigated differential prey vulnerability and development of foraging behavior of juvenile Largemouth Bass (30–75 mm) in experiments conducted in a 750‐L tank. Prey increased schooling and distance maintained from predators as they grew, but all sizes of Largemouth Bass foraged similarly, suggesting differences in predation success were due to prey morphology and species‐specific behavioral responses of prey. Results of our study can provide better predictions for prey consumption patterns of piscivorous juvenile Largemouth Bass in field settings.
Influence of Postcapture Ventilation Assistance on Migration Success of Adult Sockeye Salmon following Capture and Release
Authors: Robinson Kendra A. , Hinch Scott G. , Raby Graham D. , Donaldson Michael R. , Robichaud Dave , Patterson David A. , Cooke Steven J.
Published: June 2015

Catch and release is a tactic employed in recreational fisheries to help conserve and sustain fish populations, but postrelease mortality can occur when fish fail to recover from the stress and exhaustion of capture. Depending on factors like the duration of the stressor and whether air exposure occurs, fish can be lethargic or have negative equilibrium upon release; some anglers are motivated to attempt to manually revive fish upon release by assisting with water flow across the gills. Indeed, some management agencies and angling groups recommend different recovery techniques, but very little scientifically defensible evidence exists about the utility of assisted ventilation. We conducted two separate field experiments on Sockeye Salmon Oncorhynchus nerka in the lower Fraser River basin in which fish were (1) exposed to a standardized exercise stressor with air exposure or (2) angled by volunteer anglers and air exposed, with a subset of fish in each experiment then being provided with 1 min of assisted ventilation before release with a radio transmitter. Assisted ventilation took the form of simply holding the fish below the water surface, facing into a flow of ∼0.5 m/s. Postrelease behavior and migration success were examined in both experiments by radio‐tracking fish, using a combination of fixed stations and manual tracking. Our results from both experiments provide no support for the utility of this revival technique in benefiting the migration success of Sockeye Salmon exhausted from a capture‐and‐release event. Future experiments should test the survival and physiological benefits of different revival techniques and durations for fish at different levels of postcapture impairment.
Characterization of Isolates of Streptococcus agalactiae from Diseased Farmed and Wild Marine Fish from the U.S. Gulf Coast, Latin America, and Thailand
Authors: Soto Esteban , Wang Rui , Wiles Judy , Baumgartner Wes , Green Christopher , Plumb John , Hawke John
Published: June 2015

We examined Lancefield serogroup B Streptococcus isolates recovered from diseased, cultured hybrid Striped Bass (Striped Bass Morone saxatilis × White Bass M. chrysops) and wild and cultured Gulf Killifish Fundulus grandis from coastal waters of the U.S. Gulf of Mexico (Gulf coast) and compared those isolates to strains from tilapias Oreochromis spp. reared in Mississippi, Thailand, Ecuador, and Honduras and to the original Gulf coast strain identified by Plumb et al. (1974). The isolates were subjected to phylogenetic, biochemical, and antibiotic susceptibility analyses. Genetic analysis was performed using partial sequence comparison of (1) the 16S ribosomal RNA (rRNA) gene; (2) the sipA gene, which encodes a surface immunogenic protein; (3) the cspA gene, which encodes a cell surface-associated protein; and (4) the secY gene, which encodes components of a general protein secretion pathway. Phylogenies inferred from sipA, secY, and cspA gene sequence comparisons were more discriminating than that inferred from the 16S rRNA gene sequence comparison. The U.S. Gulf coast strains showed a high degree of similarity to strains from South America and Central America and belonged to a unique group that can be distinguished from other group B streptococci. In agreement with the molecular findings, biochemical and antimicrobial resistance analyses demonstrated that the isolates recovered from the U.S. Gulf coast and Latin America were more similar to each other than to isolates from Thailand. Three laboratory challenge methods for inducing streptococcosis in Gulf Killifish were evaluated—intraperitoneal (IP) injection, immersion (IMM), and immersion plus abrasion (IMMA)—using serial dilutions of S. agalactiae isolate LADL 97-151, a representative U.S. Gulf coast strain. The dose that was lethal to 50% of test fish by 14 d postchallenge was approximately 2 CFU/fish via IP injection. In contrast, the fish that were challenged via IMM or IMMA presented cumulative mortality less than 40% by 14 d postchallenge.

Received July 31, 2014; accepted March 11, 2015
Eye movements reflect and shape strategies in fraction comparison
Authors: Ischebeck Anja , Weilharter Marina , Körner Christof
Published: June 2015

The comparison of fractions is a difficult task that can often be facilitated by separately comparing components (numerators and denominators) of the fractions—that is, by applying so-called component-based strategies. The usefulness of such strategies depends on the type of fraction pair to be compared. We investigated the temporal organization and the flexibility of strategy deployment in fraction comparison by evaluating sequences of eye movements in 20 young adults. We found that component-based strategies could account for the response times and the overall number of fixations observed for the different fraction pairs. The analysis of eye movement sequences showed that the initial eye movements in a trial were characterized by stereotypical scanning patterns indicative of an exploratory phase that served to establish the kind of fraction pair presented. Eye movements that followed this phase adapted to the particular type of fraction pair and indicated the deployment of specific comparison strategies. These results demonstrate that participants employ eye movements systematically to support strategy use in fraction comparison. Participants showed a remarkable flexibility to adapt to the most efficient strategy on a trial-by-trial basis. Our results confirm the value of eye movement measurements in the exploration of strategic adaptation in complex tasks.
The Concept of Opera
Authors: Goehr Lydia
Published: June 2015

Chapter 5 investigates opera’s concept historically, given a context in which the terms of the individual arts—music, painting, poetry, sculpture, architecture, dance, or ballet—have been contested, often by contests being staged within the artworks themselves. This context is best described as agonisticand paragonal. Connecting opera’s concept to the ancient Greek notion of agôn—contest/debate—and to the Renaissance idea of the paragone—comparison/contest—opens up a two-fold path. It leads the concept, via a “fatherly” hand, to its claimed origins in Classical Athens and, via a “maternal” hand, to its claimed birth in Italy. The ancestral discourse of origin and birth begs for serious deconstruction. Yet, its impact on opera’s history is pervasive and undeniable. This chapter thus investigates the discourse critically, to reveal its use and its abuse in the many histories written—pro and contra opera as an art.
Meaning
Authors: Kramer Lawrence
Published: June 2015

The distinguishing resource of meaning in opera is operatic voice—not only opera’s most obvious feature but also the source of its generic identity. To a large extent this voice defines itself as a force of rupture, something nearly impossible for other vocal modalities to assimilate or appropriate. Opera as a genre depends on the difference between its own mode of vocalization and any other. For that reason, the self-reflexive staging of opera’s dependence on this singular voice is also a primary generic feature. Opera recurrently gazes at itself through the mirror of its voice. The potentials and perplexities of this self-marking, or “re-marking,” take exemplary form in scenes from Mozart’s Don Giovanni, Wagner’s Tannhäuser, and John Adams’s Doctor Atomic.
Castrato Acts
Authors: Feldman Martha
Published: June 2015

Chapter 18 delineates issues surrounding castrati as performative beings. It explores the intersubjective dimensions of castrato performance onstage and off, including the perspectives of tourists who followed castrato appearances at opera houses while on the grand tour or encountered them in salons and churches, with special attention drawn to early modern issues of cultural tourism, celebrity culture, and singing. The chapter then explores scholars’ preoccupations with castrati since about 1980, when they began to read castrato voices through the thickly psychoanalytic lenses of Freud and Lacan and the post-structural views of Barthes, Foucault, Bakhtin, and Derrida. Finally, it examines a more recent “machine turn” in castrato studies, manifest in (1) collaborations between musicians, sound engineers, and film/TV producers who have attempted to reconstruct the castrato voice; and (2) a scholarly move toward thinking about mechanism in historical connection with ways that early modern castrati were produced and staged.
Regietheater/Director’s Theater
Authors: Müller Ulrich
Published: June 2015

This chapter discusses the meaning and history of the German term for “Director’s Theater,” which, since the 1950s, has been a favorite term of the German-speaking feuilleton and later was adopted by the international press. For the audience, not for the reviewers, it has in many cases a negative, even an aggressive meaning. The first well-known protagonists were the opera directors Wieland Wagner (Bayreuth/Stuttgart) and Walter Felsenstein (Komische Oper Berlin). The social and artistic context is presented with many details and important examples; the chapter also defines modern Regietheater as a visualization of different subtexts, including even the individual personal problems of the director. A final case study is dedicated to Joachim Herz, one of the most influential German opera directors, who “invented” several methods of interpretation that are very common today but also fiercely polemicized against opera productions that deconstructed plot and action.
Exoticism
Authors: Sheppard W. Anthony
Published: June 2015

Chapter 36 considers the difficulty in defining exoticism, in determining its contentious relationship to the concept of orientalist representation and to the analysis of cross-cultural influence, and the attempts that have been made to establish a periodization of its historical development. The discussion provides an overview of scholarly approaches to exoticism over time, focusing on those scholars who have been most active in this field and on the influence of the cultural historian and critic Edward Said. The chapter concludes with a case study of the persistence of exoticism in modernist and postmodernist operas, including in specific works by Arnold Schoenberg, Roger Sessions, Igor Stravinsky, and John Corigliano.
Operatic Images
Authors: Greenwald Helen M.
Published: June 2015

This chapter addresses the extended visual constellation of images that reflect not only opera’s devoted audiences, but also a larger segment of the public that may experience opera simply through everyday encounters with books, newspapers, and advertising. A central issue is the way composers tailored the visual components of opera to engage cultural icons and the visual milieu of an intended audience. Questions considered include: How did composers and librettists engage a culture’s visual history and use those images to transmit their message? What did the audience expect to see and what would they have understood that modern viewers cannot or do not any longer comprehend? How does opera sell itself or other products? The chapter examines caricatures, advertisements, stagecraft, and ideology. It concludes with a case study of Verdi’s 1846 Attila and its use of imagery to project a timely and meaningful political message.
Writing the History of Opera
Authors: Gossett Philip
Published: June 2015

Chapter 47 begins with a discussion of the question, “What Is Opera?” for the purpose of defining a platform for the historiography of opera. It then explores theories of genre, criticism, and biography that tend to obscure accepted definitions, leading to a deeper analysis of the relationship between a work and its creator. The central portion of the chapter concerns the fluidity of the operatic work, focusing on examples by Rossini, Verdi, Bellini, Donizetti, and several works of the twentieth and twenty-first centuries. The central issue of the chapter is the need for historians to find ways to address opera’s “complete history,” including the interrelationships of composition, performance, and revisions when writing a historical narrative for opera.
Innovation and Antitrust Policy
Authors: Cotter Thomas
Published: June 2015

Section 7.1 provides a brief overview of the role of IPRs in promoting innovation, according to standard economic theory. Section 7.2 discusses the relationship between antitrust and IP law in promoting social welfare. Section 7.3 then highlights three ways in which antitrust can play a useful role in innovation policy. Section 7.4 concludes.
Tying Arrangements
Authors: Hovenkamp Herbert , Hovenkamp Erik
Published: June 2015

Tying arrangements, sometimes known as “ties,” “tie-ins,” “tied-in sales,” or “bundles,” occur when a firm offers two separate products together, refusing to sell one of them without the other. Identifying when two things are really a single product—such as a shirt and its buttons or an automobile and its tires—has proven controversial. The dominant position looks at ordinary business practices in order to determine whether the products are commonly sold separately. Competitive harm is a threat in a very few situations involving actual market foreclosure or the use of ties to enable dominant firms to retain their market position as one technology rolls into the next. As a result, the so-called per se rule for tying is wrongheaded and ties should be addressed under the rule of reason, with fairly substantial proof requirements on challengers.
Cartels and Collusion
Authors: Levenstein Margaret , Suslow Valerie
Published: June 2015

Cartels occur in a wide range of products and industries and engage in a range of behaviors in their efforts to increase profits. This chapter discusses the variety of techniques that cartels use to set prices. They may agree to a minimum price, target prices, or specific increases (or even decreases). The timing of price announcements may be intentionally manipulated to disguise collusive activity. Cartels engage in specific behaviors that facilitate monitoring of one another’s pricing. Successful collusion thus requires extensive communication, both via private and public signals. The most important determinant of cartel breakup is effective antitrust policy. Theory suggests that cartels break up as a result of cheating by member firms tempted by short-term profits, but empirical analysis rarely finds cheating that destroys cartels. Neither cartel breakup nor cartel formation appears highly correlated with the business cycle.