bluuebunny/crossref_metadata_2025 huggingface dataset:
Femtosecond laser‐induced ionization/dissociation tandem mass spectrometry (fsLID‐MS/MS) of deprotonated phosphopeptide anions
Authors: Smith Scott A. , Kalcic Christine L. , Cui Li , Reid Gavin E.
Published: November 2013

RATIONALE

Radical‐directed dissociation techniques provide structural information which is complementary to that from conventional collision‐induced dissociation (CID). The analysis of phosphopeptide anions is warranted due to their relatively acidic character. As femtosecond laser‐induced ionization/dissociation tandem mass spectrometry (fsLID‐MS/MS) is uniquely initiated by field ionization, an investigation is warranted to determine whether fsLID may provide novel analytical utility for phosphopeptide anions.

METHODS

Twenty‐three synthetic deprotonated phosphopeptide anions were introduced into a three‐dimensional quadrupole ion trap mass spectrometer via electrospray ionization. The ion trap was interfaced with a near‐IR (802 nm) ultrashort‐pulsed (35 fs FWHM) ultrahigh‐powered (peak power ~1014 W/cm2) laser system. Performance comparisons are made with other techniques applied to phosphopeptide anion analysis, including CID, electron detachment dissociation (EDD), negative electron transfer dissociation (NETD), activated electron photodetachment dissociation (activated‐EPD), and ultraviolet photodissociation (UVPD).

RESULTS

FsLID‐MS/MS of multiply deprotonated phosphopeptide anions provides sequence information via phosphorylation‐intact a/x ions in addition to other sequence ions, satellite ions, and side‐chain losses. Novel fragmentation processes include selective c‐ion formation N‐terminal to Ser/Thr and a phosphorylation‐specific correlation between xn–98 ion abundances and phosphorylation at the nth residue. Sequencing‐quality data required about 30 s of signal averaging. fsLID‐MS/MS of singly deprotonated phosphopeptides did not yield product anions with stable trajectories, despite significant depletion of the precursor.

CONCLUSIONS

Multiply deprotonated phosphopeptide anions were sequenced via negative‐mode fsLID‐MS/MS, with phosphosite localization facilitated by a/x ion series in addition to diagnostic xn–98 ions. fsLID‐MS/MS is qualitatively competitive with other techniques. Further efficiency enhancements (e.g., implementation on a linear trap or/and higher pulse frequencies) may permit sequence analyses on chromatographic timescales. Copyright © 2013 John Wiley & Sons, Ltd.
Photopolymerizable Synthons from Glycerol Derivatives
Authors: Mhanna Ali , Sadaka Faten , Boni Gilles , Brachais Claire‐Hélène , Brachais Laurent , Couvercelle Jean‐Pierre , Plasseraud Laurent , Lecamp Laurence
Published: November 2013

Photopolymerizable monomers based on monoglycerides were prepared by a convenient two‐step procedure. The first one consists of the synthesis of highly pure monoglycerides by an organocatalyzed solvent‐free route. This process was carried out by condensation of bio‐sourced carboxylic acids (i.e. butyric, decanoic, undecylenic or stearic acids) with glycerol carbonate or glycidol in the presence of a quaternary ammonium salt as a catalyst. The obtained bio‐based monoglycerides were modified in the second step by reaction with acryloyl and methacryloyl chloride leading to a series of new diacrylated and dimethacrylated monomers. The structures of the monoglycerides, diacrylated and dimethacrylated monomers were fully characterized by spectroscopic methods. Photopolymerization investigations monitored by infrared spectroscopy were achieved under ultraviolet radiation in the presence of a photoinitiator. The resulting cross‐linked materials were analyzed by thermal gravimetric analysis, gel content determination and tests of swelling in water, ethanol and methylene chloride. Data relative to the pendulum hardness of these materials are also included.
Boundary Conformal Field Theory and the Worldsheet Approach to D-Branes
Authors: Recknagel Andreas , Schomerus Volker
Published: November 2013

Boundary conformal field theory is concerned with a class of two-dimensional quantum field theories which display a rich mathematical structure and have many applications ranging from string theory to condensed matter physics. In particular, the framework allows discussion of strings and branes directly at the quantum level. Written by internationally renowned experts, this comprehensive introduction to boundary conformal field theory reaches from theoretical foundations to recent developments, with an emphasis on the algebraic treatment of string backgrounds. Topics covered include basic concepts in conformal field theory with and without boundaries, the mathematical description of strings and D-branes, and the geometry of strongly curved spacetime. The book offers insights into string geometry that go beyond classical notions. Describing the theory from basic concepts, and providing numerous worked examples from conformal field theory and string theory, this reference is of interest to graduate students and researchers in physics and mathematics.
Complementarity in the Line of Fire
Authors: Nouwen Sarah M. H.
Published: November 2013

Of the many expectations attending the creation of the first permanent International Criminal Court, the greatest has been that the principle of complementarity would catalyse national investigations and prosecutions of conflict-related crimes and lead to the reform of domestic justice systems. Sarah Nouwen explores whether complementarity has had such an effect in two states subject to ICC intervention: Uganda and Sudan. Drawing on extensive empirical research and combining law, legal anthropology and political economy, she unveils several effects and outlines the catalysts for them. However, she also reveals that one widely anticipated effect – an increase in domestic proceedings for conflict-related crimes – has barely occurred. This finding leads to the unravelling of paradoxes that go right to the heart of the functioning of an idealistic Court in a world of real constraints.
Democracy and its Elected Enemies
Authors: Rosefielde Steven , Mills Daniel Quinn
Published: November 2013

Democracy and its Elected Enemies reveals that American politicians have usurped their constitutional authority, substituting their economic and political sovereignty for the people's. This has been accomplished by creating an enormous public service sector operating in the material interest of politicians themselves and of their big business and big social advocacy confederates to the detriment of workers, the middle class and the non-political rich, jeopardizing the nation's security in the process. Steven Rosefielde and Daniel Quinn Mills contend that this usurpation is the source of America's economic decline and fading international power, and provide an action plan for restoring 'true' democracy in which politicians only provide the services people vote for within the civil and property rights protections set forth in the constitution.
Collective Security
Authors: Tsagourias Nicholas , White Nigel D.
Published: November 2013

This analysis of collective security covers its institutional, operational and legal parameters along with the United Nations system, presenting it as a global public order institution for maintaining peace. The authors study its constitutional premises as they are shaped by the forces of law and politics. After an historical account of initiatives and projects for global peace, the authors explain the morphology of collective security as a global public order institution and outline its triggers, institutions, actors, components and tools. They go on to analyse its legal properties and the processes of political, legal and criminal accountability. The analysis and assessment are informed throughout by practice drawn from examples including Korea, Iraq and Libya, and by a wealth of cases from national and international jurisdictions.
Disasters and the American State
Authors: Roberts Patrick S.
Published: November 2013

Disasters and the American State offers a thesis about the trajectory of federal government involvement in preparing for disaster shaped by contingent events. Politicians and bureaucrats claim credit for the government's successes in preparing for and responding to disaster, and they are also blamed for failures outside of government's control. New interventions have created precedents and established organizations and administrative cultures that accumulated over time and produced a general trend in which citizens, politicians and bureaucrats expect the government to provide more security from more kinds of disasters. The trend reached its peak when the Federal Emergency Management Agency adopted the idea of preparing for 'all hazards' as its mantra. Despite the rhetoric, however, the federal government's increasingly bold claims and heightened public expectations are disproportionate to the ability of the federal government to prevent or reduce the damage caused by disaster.
Polychronicon Ranulphi Higden, monachi Cestrensis
Authors: Higden Ranulf
Published: November 2013

Ranulf Higden (d.1364) was a monk at the abbey of St Werburgh in Chester. His most important literary work is this universal chronicle, which survives in over a hundred Latin manuscripts, testifying to its popularity. The earliest version of it dates from 1327, but Higden continued writing until his death, expanding and updating the text. It was also continued in other monastic houses, most importantly by John Malvern of Worcester. The English translation made by John Trevisa in the 1380s was also widely circulated and is included in this work, published in nine volumes for the Rolls Series between 1865 and 1886. The chronicle shows how fourteenth-century scholars understood world history and geography. Volume 4 contains the rest of Book 3, on the Hellenistic period up to the birth of Christ, and the start of Book 4, up to the end of the first century CE.
Trade, Institutions, and Ethnic Tolerance: Evidence from South Asia
Authors: JHA SAUMITRA
Published: November 2013

I provide evidence that the degree to which medieval Hindus and Muslims could provide complementary, nonreplicable services and a mechanism to share the gains from exchange has resulted in a sustained legacy of ethnic tolerance in South Asian towns. Due to Muslim-specific advantages in Indian Ocean shipping, interethnic complementarities were strongest in medieval trading ports, leading to the development of institutional mechanisms that further supported interethnic exchange. Using novel town-level data spanning South Asia's medieval and colonial history, I find that medieval ports, despite being more ethnically mixed, were five times less prone to Hindu-Muslim riots between 1850 and 1950, two centuries after Europeans disrupted Muslim overseas trade dominance, and remained half as prone between 1950 and 1995. Household-level evidence suggests that these differences reflect local institutions that emerged to support interethnic medieval trade, continue to influence modern occupational choices and organizations, and substitute for State political incentives in supporting interethnic trust.
Becoming a Composer: Walther's Songs inDie Meistersinger
Authors: GROOS ARTHUR
Published: November 2013

Walther von Stolzing's songs inDie Meistersinger von Nürnberghave not attracted much critical interest, in part because of their deceptive appearance as straightforward diegetic music or stage songs. But in addition to comprising an extended ‘musical joke’ illustrating the hero's desire-driven progress towards musical competence, these songs also pursue a historicising agenda, replacing the Meistersingers' pre-modern rule-driven poetics of imitation with a modern aesthetics of inspiration.
Pioneers in Optics: George Gabriel Stokes and William Hyde Wollaston
Authors: Davidson Michael W.
Published: November 2013

Born in Ireland on August 13, 1819, George Stokes was the youngest of six children. His father, a rector, directed his early education before sending him to a school in Dublin. Stokes attended Bristol College in England, followed by Pembroke College at Cambridge University, where he studied mathematics. He graduated in 1841 and was bestowed with many honors, including a fellowship that enabled him to remain at Cambridge. In 1849, Stokes was appointed Lucasian Professor of Mathematics and spent the rest of his life working at the prestigious school.
99mTc-labeled benzothiazole and stilbene derivatives as imaging agents for Aβ plaques in cerebral amyloid angiopathy
Authors: Jia Jianhua , Cui Mengchao , Dai Jiapei , Wang Xuedan , Ding Yu-Shin , Jia Hongmei , Liu Boli
Published: November 2013

99mTc-labeled probes in this study for the Aβ plaques in the blood vessels of the brain may be used as SPECT imaging agents for the diagnosis of CAA.
Retracted Article: Red luminescent manganese-doped zinc sulphide nanocrystals and their antibacterial study
Authors: Singh Prashant K. , Sharma Prashant K. , Kumar Manvendra , Dutta Ranu , Sundaram Shanthy , Pandey Avinash C.
Published: November 2013

The red luminescence of ZnS:Mn2+ nanocrystals at ∼612 nm and the broad spectrum antibacterial activity of biotin capped ZnS:Mn2+ nanocrystals.
Wideband simplified feed for printed log‐periodic dipole array antenna
Authors: Zhai G.H. , Cheng Y. , Min D. , Zhu S.Z. , Gao J.J.
Published: November 2013

A novel simple approach is presented for designing a broadband single layer substrate printed log‐periodic dipole array (PLPDA) antenna by using microstrip technology. The PLPDA antenna has the merits of wide bandwidth, low profile and light weight, which should be fed by the balanced line. The balanced line, created by the geometric features of the microstrip, provides a balun with a considerably wide bandwidth with low profile, broad bandwidth and low insertion loss etc. The prototype of the proposed microstrip printed log‐periodic array at Ka band is designed and fabricated; the measured data are in good agreement with the simulated results.
Improved bounds on restricted isometry constant for orthogonal matching pursuit
Authors: Wen Jinming , Zhu Xiaomei , Li Dongfang
Published: November 2013

First, a counter example is constructed to show that for any given positive integer K ≥ 2 and for any (1/√K + 1) ≤ t < 1, there always exists a K‐sparse x and a matrix A with the restricted isometry constant δK+1 = t such that the orthogonal matching pursuit (OMP) algorithm fails in K iterations. Secondly, it is shown that even when δK + 1 = (1/(√K + 1)), the OMP algorithm can also perfectly recover every K‐sparse vector x from y = Ax in K iterations. This improves the best existing results which were independently given by Mo and Shen and Wang and Shim.
Efficiency and reliability of Fowler‐Nordheim tunnelling in CMOS floating‐gate transistors
Authors: Rumberg B. , Graham D.W.
Published: November 2013

Floating‐gate transistors are increasingly used for digital and/or analogue non‐volatile memory in standard CMOS integrated circuits. The mask design of the floating‐gate's tunnelling junction, where erasure and/or writing occur, is examined. Aided by static and transient tunnelling current measurements for a variety of tunnelling junctions, recommendations for constructing these junctions to minimise the duration, power consumption and oxide degradation of programming are presented.
Study of a geo‐multicast framework for efficient message dissemination at unmanned level crossings
Authors: Ansari Keyvan , Feng Yanming , Singh Jack
Published: November 2013

Collisions among trains and cars at road/rail level crossings (LXs) can have severe consequences such as high level of fatalities, injuries and significant financial losses. As communication and positioning technologies have significantly advanced, implementing vehicular ad hoc networks (VANETs) in vicinity of unmanned LXs, generally LXs without barriers, is seen as an efficient and effective approach to mitigate or even eliminate collisions without imposing huge infrastructure costs. VANETs necessitate unique communication strategies, in which routing protocols take a prominent part in their scalability and overall performance, through finding optimised routes quickly and with low bandwidth overheads. This article studies a novel geo‐multicast framework that incorporates a set of models for communication, message flow and geo‐determination of endangered vehicles with a reliable receiver‐based geo‐multicast protocol to support cooperative level crossings (CLXs), which provide collision warnings to the endangered motorists facing road/rail LXs without barriers. This framework is designed and studied as part of a $5.5 m Government and industry funded project, entitled ‘Intelligent‐Transport‐Systems to improve safety at road/rail crossings’. Combined simulation and experimental studies of the proposed geo‐multicast framework have demonstrated promising outcomes as cooperative awareness messages provide actionable critical information to endangered drivers who are identified by CLXs.
Groove optimization for drag reduction
Authors: Mohammadi A. , Floryan J. M.
Published: November 2013

Optimal shapes of laminar, drag reducing longitudinal grooves in a pressure driven flow have been determined. It has been shown that such shapes can be characterized using reduced geometry models involving only a few Fourier modes. Two classes of grooves have been studied, i.e., the equal-depth grooves, which have the same height and depth, and the unequal-depth grooves. It has been shown that the optimal shape in the former case can be approximated by a certain universal trapezoid. There exists an optimum depth in the latter case and this depth, combined with the corresponding groove shape, defines the optimal geometry; this shape is well-approximated by a Gaussian function. Drag reduction due to the use of the optimal grooves has been determined. The analysis has been extended to kinematically driven flows. It has been shown that in this case the longitudinal grooves always increase the flow resistance.
Internal wave and boundary current generation by tidal flow over topography
Authors: Dettner Amadeus , Swinney Harry L. , Paoletti M. S.
Published: November 2013

The relationship between boundary currents generated by tidal flow over topography and the radiated internal wave power is examined in two-dimensional numerical simulations of a uniformly stratified fluid. The radiated power PIW and kinetic energy density of the boundary currents are computed as a function of the internal wave slope SIW and the criticality parameter ε (ratio of the maximum topographic slope to SIW). Both SIW and ε are varied two orders of magnitude about unity by changing the tidal frequency, stratification, or topographic shape and slope. We consider cases where the hydrostatic approximation is valid (SIW ≪ 1), as well as test theoretical predictions for models of the deep ocean where the beam slope diverges and the hydrostatic approximation fails. We confirm that resonant boundary currents characterized by large kinetic energy densities form over critical topography (ε = 1). However, we find that this resonance phenomenon does not extend to the power radiated by internal waves that propagate away from the topography. Further, by directly comparing the kinetic energy density to the energy flux of the generated internal waves, we find that the more easily measured kinetic energy density cannot be used as a proxy to characterize the conversion of tidal energy to radiated internal wave power. Whether the hydrostatic approximation is valid or fails, our measurements of the radiated power can be described as PIW = Ptidef (ε, shape)/SIW, where Ptide is the effective tidal power that interacts with the topography, and π/8 < f (ε, shape) < π/4 is bounded below by the theoretical prediction of Bell [“Topographically generated internal waves in the open ocean,” J. Geophys. Res. 80, 320–327 (1975)] for ε → 0 and above by Llewellyn Smith and Young [“Tidal conversion at a very steep ridge,” J. Fluid Mech. 495, 175–191 (2003)] for ε → ∞.
Microwave resonances in dielectric samples probed in Corbino geometry: Simulation and experiment
Authors: Felger M. Maximilian , Dressel Martin , Scheffler Marc
Published: November 2013

The Corbino approach, where the sample of interest terminates a coaxial cable, is a well-established method for microwave spectroscopy. If the sample is dielectric and if the probe geometry basically forms a conductive cavity, this combination can sustain well-defined microwave resonances that are detrimental for broadband measurements. Here, we present detailed simulations and measurements to investigate the resonance frequencies as a function of sample and probe size and of sample permittivity. This allows a quantitative optimization to increase the frequency of the lowest-lying resonance.
Transport spectroscopy of a graphene quantum dot fabricated by atomic force microscope nanolithography
Authors: Puddy R. K. , Chua C. J. , Buitelaar M. R.
Published: November 2013

We report low-temperature transport spectroscopy of a graphene quantum dot fabricated by atomic force microscope nanolithography. The excellent spatial resolution of the atomic force microscope allows us to reliably fabricate quantum dots with short constrictions of less than 15 nm in length. Transport measurements demonstrate that the device is dominated by a single quantum dot over a wide gate range. The electron spin system of the quantum dot is investigated by applying an in-plane magnetic field. The results are consistent with a Landé g-factor ∼2 but no regular spin filling sequence is observed, most likely due to disorder.
Fast identification of wheat 1BL.1RS translocation by reversed-phase ultra-performance liquid chromatography (RP-UPLC)
Authors: Zhou Jianwen , Han Caixia , Cao Hui , Zhen Shoumin , Yu Zitong , Li Xiaohui , Ma Wujun , Yan Yueming
Published: November 2013

The 1BL.1RS chromosomal translocation in wheat is the result of replacement of the short arm of chromosome 1B of wheat by the short arm of chromosome 1R of rye, which had been widely used as a parental line in worldwide wheat breeding, resulting in a high percentage of wheat cultivars containing this translocation. A fast and reliable approach to identify this translocation is highly desirable in modern wheat breeding. This study compared reversed-phase ultra-performance liquid chromatography (RP-UPLC), acidic polyacrylamide gel electrophoresis (A-PAGE), liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), allelic-specific PCR, and reversed-phase high-performance liquid chromatography (RP-HPLC) approaches to identify the 1BL.1RS translocation in 76 bread wheat cultivars. Two gliadin bands in the Gli-B1 region of A-PAGE separation were confirmed by LC-MS/MS to be omega secalins from the 1BL.1RS translocation, and they can be used as reliable protein markers for identifying the translocation. A few specific minor peaks eluted at 12–13 min on the RP-UPLC patterns can readily differentiate the 1BL.1RS translocation. Of the 76 wheat cultivars tested, 40 were identified as carrying the 1BL.1RS translocation by RP-UPLC, which was consistent with the results of A-PAGE, HPLC, and PCR. Compared with other established methods, RP-UPLC showed a clear advantage in fast identification of the 1BL.1RS translocation with higher reliability and lower costs, and it is therefore ideal for large-scale screening of the 1BL.1RS translocation in wheat breeding.
Selective inhibitor of endosomal trafficking pathways exploited by multiple toxins and viruses
Authors: Gillespie Eugene J. , Ho Chi-Lee C. , Balaji Kavitha , Clemens Daniel L. , Deng Gang , Wang Yao E. , Elsaesser Heidi J. , Tamilselvam Batcha , Gargi Amandeep , Dixon Shandee D. , France Bryan , Chamberlain Brian T. , Blanke Steven R. , Cheng Genhong , de la Torre Juan Carlos , Brooks David G. , Jung Michael E. , Colicelli John , Damoiseaux Robert , Bradley Kenneth A.
Published: November 2013

Significance

Bacterial and viral infections are a significant public health burden. To corrupt normal host cellular functions, many bacterial toxins and all viruses must gain entry to host cells, a process that exploits the host’s own cellular machinery. In this study, we use high-throughput technologies to screen for chemical inhibitors of bacterial toxin and viral entry. We report the discovery of a small molecule that inhibits several viruses and bacterial toxins. In addition to the therapeutic potential, this compound represents a powerful probe for dissecting the mechanisms of mammalian membrane trafficking processes.
Molecular determinants of PI3Kγ-mediated activation downstream of G-protein–coupled receptors (GPCRs)
Authors: Vadas Oscar , Dbouk Hashem A. , Shymanets Aliaksei , Perisic Olga , Burke John E. , Abi Saab Widian F. , Khalil Bassem D. , Harteneck Christian , Bresnick Anne R. , Nürnberg Bernd , Backer Jonathan M. , Williams Roger L.
Published: November 2013

Significance

Pathology of many diseases depends on signaling by phosphoinositide 3-kinase gamma (PI3Kγ), the lipid kinase that is exquisitely adapted to activation downstream of heterotrimeric G-protein–coupled receptors (GPCRs). Using hydrogen–deuterium exchange mass spectrometry, we demonstrate the mechanism by which the p110γ catalytic subunit and its p101 regulatory subunit interact with G-protein Gβγ heterodimers liberated upon GPCR activation. We identify residues in both p110γ and p101 interacting with Gβγ heterodimers on membranes. This enabled us to generate Gβγ-insensitive p110γ and p101 variants that eliminate activation of PI3Kγ by Gβγs without affecting the enzyme’s basal activity or its activation by the small G-protein Ras. Ablating the interaction of PI3Kγ with Gβγ heterodimers attenuates signaling, chemotaxis, and transformation driven by a GPCR agonist in cell lines.
Mutually opposing forces during locomotion can eliminate the tradeoff between maneuverability and stability
Authors: Sefati Shahin , Neveln Izaak D. , Roth Eatai , Mitchell Terence R. T. , Snyder James B. , MacIver Malcolm A. , Fortune Eric S. , Cowan Noah J.
Published: November 2013

Significance

Animals often produce substantial forces in directions that do not directly contribute to movement. For example, running and flying insects produce side-to-side forces as they travel forward. These forces generally “cancel out,” and so their role remains a mystery. Using a multidisciplinary approach, we show that mutually opposing forces can enhance both maneuverability and stability at the same time, although at some energetic cost. In addition to challenging the maneuverability–stability dichotomy within locomotion, our results challenge the same tradeoff within the engineering of mobile robots. This may inspire the exploration of a new set of strategies for the design and control of mobile systems.
Stable three-dimensional metallic carbon with interlocking hexagons
Authors: Zhang Shunhong , Wang Qian , Chen Xiaoshuang , Jena Puru
Published: November 2013

Significance

Carbon is an amazing material: it not only forms the chemical basis for all known life but also, because of its rich physics and chemistry, displays an array of structures: from the age-old graphite and diamond to more recent C
60
fullerene, 1D nanotube, and 2D graphene. One of the unsolved issues in carbon science has been to find a 3D form of carbon that is metallic under ambient conditions. This paper addresses this important challenge. Using state-of-the-art theoretical calculations, we predict the existence of such a phase that is formed from interlocking hexagons and is dynamically, mechanically, and thermally stable. It is suggested that this new form of carbon may be synthesized chemically by using benzene or polyacenes molecules.
Estrogen receptor (ER) β expression in oligodendrocytes is required for attenuation of clinical disease by an ERβ ligand
Authors: Khalaj Anna J. , Yoon JaeHee , Nakai Jaspreet , Winchester Zachary , Moore Spencer M. , Yoo Timothy , Martinez-Torres Leonardo , Kumar Shalini , Itoh Noriko , Tiwari-Woodruff Seema Kaushalya
Published: November 2013

Significance

Multiple sclerosis (MS) is a debilitating neurodegenerative disease characterized by inflammation and demyelination. Immunomodulatory agents slow, but do not prevent, disease progression and offer only indirect neuroprotection. The estrogen receptor β (ERβ) ligand diarylpropionitrile (DPN) has direct neuroprotective effects in a mouse model of MS by stimulating endogenous myelination. Here we elucidate the cell type(s) mediating DPN’s effects. Conditional knockout of ERβ in oligodendrocyte (OL) lineage cells prevented DPN-induced improvement in clinical disease and myelination, partially prevented callosal conduction improvement, and prevented activation of a pathway implicated in OL survival/axon myelination. Our results indicate that DPN-conferred neuroprotection in a mouse model of MS is mediated by ERβ in OLs and inform highly targeted pharmacotherapeutic approaches to MS treatment.
ADP-ribosyl-acceptor hydrolase 3 regulates poly (ADP-ribose) degradation and cell death during oxidative stress
Authors: Mashimo Masato , Kato Jiro , Moss Joel
Published: November 2013

Significance

Poly (ADP-ribose) (PAR) participates in initiating parthanatos, cell death mediated by apoptosis-inducing factor (AIF), following genotoxic stress. PAR translocation from the nucleus to cytoplasm is an essential step for AIF-mediated cell death. Here, we report that poly (ADP-ribose) glycohydrolase (PARG) enhances PAR translocation by releasing protein-free PAR fragments from nuclear acceptor proteins. ADP-ribosyl-acceptor hydrolase (ARH) 3 lowers PAR levels in the nucleus and cytoplasm, preventing PAR translocation and then parthanatos. Elucidation of the sequential action of PARG and ARH3 in the PAR-mediated pathway provides a better understanding of mechanisms underlying oxidative stress and may lead to new therapeutic targets.
Conformational inactivation induces immunogenicity of the receptor-binding pocket of a bacterial adhesin
Authors: Kisiela Dagmara I. , Rodriguez Victoria B. , Tchesnokova Veronika , Avagyan Hovhannes , Aprikian Pavel , Liu Yan , Wu Xue-Ru , Thomas Wendy E. , Sokurenko Evgeni V.
Published: November 2013

Significance

Antibodies targeting the receptor-binding pocket of viral and bacterial adhesins are highly protective against infection. However, functional site epitopes in the antigens are not always highly immunogenic, possibly because of the binding epitope-masking effects of natural ligand–receptor interactions. By using the mannose-specific fimbrial adhesin of
Escherichia coli
, FimH, we demonstrate that locking the adhesin in a low-binding conformation abrogates its capability to interact with mannose but, at the same time, facilitates the immune response against binding-pocket epitopes and production of adhesion-inhibitory antibodies. We believe our findings provide insight into strategies to elicit neutralizing and functional antibodies against a broad spectrum of receptor-binding proteins.
Honey bees selectively avoid difficult choices
Authors: Perry Clint J. , Barron Andrew B.
Published: November 2013

Significance

Here we show that honey bees (
Apis mellifera
) can adaptively alter their behavior in a choice test in response to trial difficulty. Bees preferentially opt out of difficult trials and by doing so, improve their success rate. We discuss whether this choice involves assessing degree of uncertainty (considered a definition of basic metacognition) or whether this task might be solved by associative mechanisms. We propose a hypothesis for how uncertainty might be processed within the known circuitry of the insect brain to frame the concept of uncertainty as a topic for neurobiological analysis.
Regulatory R region of the CFTR chloride channel is a dynamic integrator of phospho-dependent intra- and intermolecular interactions
Authors: Bozoky Zoltan , Krzeminski Mickael , Muhandiram Ranjith , Birtley James R. , Al-Zahrani Ateeq , Thomas Philip J. , Frizzell Raymond A. , Ford Robert C. , Forman-Kay Julie D.
Published: November 2013

Significance

Intrinsically disordered proteins lack persistent folded structure but are abundant and critical for regulatory protein interactions. They represent a challenge to the structure/function paradigm, particularly when significant disorder remains on interaction with partners. Although many disordered protein interactions have been described, little is known about multiple interactions of hub proteins or dependence on posttranslational modifications of the interaction network from a biophysical perspective. Cystic fibrosis transmembrane conductance regulator (CFTR), the chloride channel mutated in cystic fibrosis, is controlled by a disordered, phosphorylated regulatory region. Our detailed characterizations of phosphorylation-dependent interactions of the regulatory region and structural models of its highly dynamic complexes provide direct insight into the basis of CFTR regulation and the general binding mechanisms of disordered hub proteins.
Photoswitchable nanoparticles for in vivo cancer chemotherapy
Authors: Tong Rong , Chiang Homer H. , Kohane Daniel S.
Published: November 2013

Significance

The importance of this research is in the demonstration of the effectiveness and improved safety of a nanoparticulate chemotherapeutic formulation that can be phototriggered to shrink in size at the tumor site. That shrinkage enhanced nanoparticle penetration into tumors and also triggered local drug release. The result was increased efficacy and reduced systemic toxicity. The phototriggered formulation also relieved the compression of tumor blood vessels, which is a recognized barrier to nanoparticle accumulation in tumors.
Rescue of a primary myelofibrosis model by retinoid-antagonist therapy
Authors: Hong Suk-Hyun , Dvorak-Ewell Melita , Stevens Hazel Y. , Barish Grant D. , Castro Glenda L. , Nofsinger Russell , Frangos John A. , Shoback Dolores , Evans Ronald M.
Published: November 2013

Significance

Our work identifies a therapeutically tractable yet previously unrecognized repressive epigenetic feature of primary myelofibrosis that controls a key cytokine circuit in the bone marrow microenvironment. Though lacking previous clinical utility, we show that an orally active retinoic acid receptor antagonist can normalize thrombopoietin production, restore bone integrity, and dramatically reduce fibrosis. This identification of a pathway-specific drug for primary myelofibrosis opens up an avenue of treatment options and provides insight into the complex mechanisms underlying myelofibrosis.
Neural mechanisms of reactivation-induced updating that enhance and distort memory
Authors: St. Jacques Peggy L. , Olm Christopher , Schacter Daniel L.
Published: November 2013

Significance

Reactivation is a key process that updates memory by strengthening existing memories and incorporating relevant new information, thus supporting the dynamic and flexible nature of memory. This adaptive function, however, can sometimes contribute to memory distortions. The current study examines how neural mechanisms that operate during reactivation of memories for a museum tour contribute to enhancement of existing memories, while also supporting integration of novel information that can contribute to false memories. Our results reveal similarities and differences in the neural mechanisms of reactivation associated with subsequent true and false memories for real-world events, thereby illuminating how memories change over time as a consequence of reactivation—a process that has important implications for understanding the unreliability of eyewitness memories.
Two appendages homologous between basal bodies and centrioles are formed using distinct Odf2 domains
Authors: Tateishi Kazuhiro , Yamazaki Yuji , Nishida Tomoki , Watanabe Shin , Kunimoto Koshi , Ishikawa Hiroaki , Tsukita Sachiko
Published: November 2013

Ciliogenesis is regulated by context-dependent cellular cues, including some transduced through appendage-like structures on ciliary basal bodies called transition fibers and basal feet. However, the molecular basis for this regulation is not fully understood. The Odf2 gene product, ODF2/cenexin, is essential for both ciliogenesis and the formation of the distal and subdistal appendages on centrioles, which become basal bodies. We examined the effects of Odf2 deletion constructs on ciliogenesis in Odf2-knockout F9 cells. Electron microscopy revealed that ciliogenesis and transition fiber formation required the ODF2/cenexin fragment containing amino acids (aa) 188–806, whereas basal foot formation required aa 1–59 and 188–806. These sequences also formed distal and subdistal appendages, respectively, indicating that the centriole appendages are molecularly analogous to those on basal bodies. We used the differential formation of appendages by Odf2 deletion constructs to study the incorporation and function of molecules associated with each appendage type. We found that transition fibers and distal appendages were required for ciliogenesis and subdistal appendages stabilized the centrosomal microtubules.
Lysosomal sorting receptors are essential for secretory granule biogenesis in Tetrahymena
Authors: Briguglio Joseph S. , Kumar Santosh , Turkewitz Aaron P.
Published: November 2013

Secretory granules, such as neuronal dense core vesicles, are specialized for storing cargo at high concentration and releasing it via regulated exocytosis in response to extracellular stimuli. Here, we used expression profiling to identify new components of the machinery for sorting proteins into mucocysts, secretory granule-like vesicles in the ciliate Tetrahymena thermophila. We show that assembly of mucocysts depends on proteins classically associated with lysosome biogenesis. In particular, the delivery of nonaggregated, but not aggregated, cargo proteins requires classical receptors of the sortilin/VPS10 family, which indicates that dual mechanisms are involved in sorting to this secretory compartment. In addition, sortilins are required for delivery of a key protease involved in T. thermophila mucocyst maturation. Our results suggest potential similarities in the formation of regulated secretory organelles between even very distantly related eukaryotes.
Self-organized rhythmic patterns in geochemical systems
Authors: L'Heureux Ivan
Published: November 2013

Chemical oscillating patterns are ubiquitous in geochemical systems. Although many such patterns result from systematic variations in the external environmental conditions, it is recognized that some patterns are due to intrinsic self-organized processes in a non-equilibrium nonlinear system with positive feedback. In rocks and minerals, periodic precipitation (Liesegang bands) and oscillatory zoning constitute good examples of patterns that can be explained using concepts from nonlinear dynamics. Generally, as the system parameters exceed some threshold values, the steady (time-independent) state characterizing the system loses its stability. The system then evolves towards other time-dependent solutions (‘attractors’) that may have an oscillatory behaviour or a complex chaotic one. In this review, we describe many of these pattern types taken from a variety of geological environments: eruptive, sedimentary, hydrothermal or metamorphic. One particular example (periodic precipitation of pyrite bands in an evolving sapropel sediment) is presented here for the first time. This will help in convincing the reader that the tools of nonlinear dynamics may be useful to understand the history of our planet.
Bifurcation dynamics of natural drainage networks
Authors: Petroff Alexander P. , Devauchelle Olivier , Seybold Hansjörg , Rothman Daniel H.
Published: November 2013

As water erodes a landscape, streams form and channellize the surficial flow. In time, streams become highly ramified networks that can extend over a continent. Here, we combine physical reasoning, mathematical analysis and field observations to understand a basic feature of network growth: the bifurcation of a growing stream. We suggest a deterministic bifurcation rule arising from a relationship between the position of the tip in the network and the local shape of the water table. Next, we show that, when a stream bifurcates, competition between the stream and branches selects a special bifurcation angleα=2π/5. We confirm this prediction by measuring several thousand bifurcation angles in a kilometre-scale network fed by groundwater. In addition to providing insight into the growth of river networks, this result presents river networks as a physical manifestation of a classical mathematical problem: interface growth in a harmonic field. In the final sections, we combine these results to develop and explore a one-parameter model of network growth. The model predicts the development of logarithmic spirals. We find similar features in the kilometre-scale network.
The secret gardener: vegetation and the emergence of biogeomorphic patterns in tidal environments
Authors: Da Lio Cristina , D'Alpaos Andrea , Marani Marco
Published: November 2013

The presence and continued existence of tidal morphologies, and in particular of salt marshes, is intimately connected with biological activity, especially with the presence of halophytic vegetation. Here, we review recent contributions to tidal biogeomorphology and identify the presence of multiple competing stable states arising from a two-way feedback between biomass productivity and topographic elevation. Hence, through the analysis of previous and new results on spatially extended biogeomorphological systems, we show that multiple stable states constitute a unifying framework explaining emerging patterns in tidal environments from the local to the system scale. Furthermore, in contrast with traditional views we propose that biota in tidal environments is not just passively adapting to morphological features prescribed by sediment transport, but rather it is ‘The Secret Gardener’, fundamentally constructing the tidal landscape. The proposed framework allows to identify the observable signature of the biogeomorphic feedbacks underlying tidal landscapes and to explore the response and resilience of tidal biogeomorphic patterns to variations in the forcings, such as the rate of relative sea-level rise.
Molecular epidemiology of paramyxoviruses in Zambian wild rodents and shrews
Authors: Sasaki Michihito , Muleya Walter , Ishii Akihiro , Orba Yasuko , Hang’ombe Bernard M. , Mweene Aaron S. , Moonga Ladslav , Thomas Yuka , Kimura Takashi , Sawa Hirofumi
Published: November 2013

Rodents and shrews are known to harbour various viruses. Paramyxoviruses have been isolated from Asian and Australian rodents, but little is known about them in African rodents. Recently, previously unknown paramyxovirus sequences were found in South African rodents. To date, there have been no reports related to the presence and prevalence of paramyxoviruses in shrews. We found a high prevalence of paramyxoviruses in wild rodents and shrews from Zambia. Semi-nested reverse transcription-PCR assays were used to detect paramyxovirus RNA in 21 % (96/462) of specimens analysed. Phylogenetic analysis revealed that these viruses were novel paramyxoviruses and could be classified as morbillivirus- and henipavirus-related viruses, and previously identified rodent paramyxovirus-related viruses. Our findings suggest the circulation of previously unknown paramyxoviruses in African rodents and shrews, and provide new information regarding the geographical distribution and genetic diversity of paramyxoviruses.
catena-Poly[N,N,N′,N′-tetramethylethylendiammonium [[tetrabromidoantimonate(III)]-μ-bromido] hemihydrate]
Authors: Kharrat Houda , Kamoun Slaheddine , Michaud François
Published: November 2013

The asymmetric unit of the title compound {(C6H18N2)2[Sb2Br10]·H2O}n, consists of two tetramethylethylendiammonium cations that are located on centres of inversion, as well as one tetramethylethylendiammonium cation, one water molecule, one distorted octahedral [SbBr6]3−anion and one bisphenoidal [SbBr4]−anion in general positions. The [SbBr6]3−and [SbBr4]−anions are linked together by two long Sb—Br bonds of 3.2709 (8) and 3.5447 (7) Å into {[Sb2Br10]4−}nchains along [001]. One of the three tetramethylethylendiammonium cations is disordered and was refined using a split model (occupancy ratio 0.58:0.42). The cations and the water molecule are connected to the {[Sb2Br10]4−}npolymeric anions by weak N—H ...Br and O(water)—H ...Br hydrogen bonding.
1-Nitro-4-(4-nitrophenoxy)benzene: a second monoclinic polymorph
Authors: Naz Mehwish , Akhter Zareen , McKee Vickie , Nadeem Arif
Published: November 2013

In the title compound, C12H8N2O5, the aromatic rings are inclined to one another by 56.14 (7)°. The nitro groups are inclined by to the benzene rings to which they are attached by 3.86 (17) and 9.65 (15)°. In the crystal, molecules are linked by C—H...O hydrogen bonds, forming a three-dimensional structure. The title compound is a new monoclinic polymorph, crystallizing in space groupP21/c. The first polymorph crystallized in space groupC2/cand the molecule possesses twofold rotation symmetry. Two low-temperature structures of this polymorph (150 K and 100 K, respectively) have been reported [Meciarovaet al.(2004). Private Communication (refcode IXOGAD). CCDC, Cambridge, England, and Dey & Desiraju (2005).Chem. Commun.pp. 2486–2488].
Bis(2,2′-bipyridine)[1,9-bis(diphenylphosphanyl)-1,2,3,4,6,7,8,9-octahydropyrimido[1,2-a]pyrimidin-5-ium]ruthenium(II) hexafluoridophosphate dibromide dichloromethane disolvate monohydrate
Authors: Shang Congcong , Vendier Laure , Sutra Pierre , Igau Alain
Published: November 2013

In the cation of the title complex, [Ru(C31H32N3P2)(C10H8N2)2](PF6)(Br)2·2CH2Cl2·H2O, the ruthenium ion is coordinated in a distorted octahedral geometry by two 2,2′-bipyridine (bpy) ligands and a chelating cationicN-diphenylphosphino-1,3,4,6,7,8-hexahydro-2-pyrimido[1,2-a]pyrimidine [(PPh2)2-hpp] ligand. The tricationic charge of the complex is balanced by two bromide and one hexafluoridophosphate counter-anions. The compound crystallized with two molecules of dichloromethane (one of which is equally disordered about a Cl atom) and a water molecule. In the crystal, one of the Br anions bridges two water moleculesviaO—H...Br hydrogen bonds, forming a centrosymmetric diamond-shapedR42(8) motif. The cation and anions and the solvent molecules are linkedviaC—H...F, C—H...Br, C—H...Cl and C—H...O hydrogen bonds, forming a three-dimensional network.
N1-(Thiophen-2-ylmethyl)-N3,N3-bis[3-(thiophen-2-ylmethylammonio)propyl]propane-1,3-diammonium hexafluoridosilicate methanol trisolvate
Authors: Haque Syed A. , Cooper Dominique N. , Powell Douglas R. , Venkatraman Ramaiyer , Hossain Md. Alamgir
Published: November 2013

In the title compound, C24H40N4S34+·2SiF62−·3CH3OH, the central tertiary amine function is protonated and is connected to three thiophen-2-ylmethylamino-n-propyl groups, forming the arms of a T-shaped cation that has two pockets. Each arm contains one protonated secondary amine function, and each pocket is occupied by one SiF62−anion bondedviatwo N—H...F interactions with the protonated amine group on the middle arm, while two methanol solvent molecules are N—H...O hydrogen-bonded with the other secondary protonated amine groups on the side arms. Weak O—H...O and O—H...F hydrogen bonds between the solvent molecules and between the solvent molecules and the anions, respectively, are also observed. All three thiophene groups in the arms are disordered over two sets of sites, with occupancy ratios of 0.828 (3):0.172 (3), 0.910 (2):0.090 (2) and 0.890 (3):0.110 (3).
Di-μ-oxido-bis({2,2′-[ethane-1,2-diylbis(nitrilomethanylylidene)]diphenolato}titanium(IV)) chloroform disolvate
Authors: Zaitsev Kirill V. , Karlov Sergey S. , Piskun Yulia A. , Vasilenko Irina V. , Churakov Andrei V.
Published: November 2013

In the title structure, [Ti2(C16H16N2O2)2O2]·2CHCl3, the Ti atom is coordinated in a distorted octahedral geometry by theO,N,N′,O′ donor set of the salalen ligand and by two μ2-oxide O atoms, which bridge two Ti(salalen) fragments into a centrosymmetric dimeric unit. In the central Ti2(μ2-O)2fragment, the metal–oxygen distances are significantly different [1.7962 (19) and 1.9292 (19) Å]. In the crystal, the chloroform molecule is anchoredviaan N—H...Cl and a bifurcated C—H...(O,O) hydrogen bond. Slipped π–π stacking [shortest C...C distance = 3.585 (4) Å] and C—H...π interactions contribute to the coherence of the structure.