bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibition of Hepatitis C Virus Replication by GS-6620, a Potent
C
-Nucleoside Monophosphate Prodrug
Authors: Feng Joy Y. , Cheng Guofeng , Perry Jason , Barauskas Ona , Xu Yili , Fenaux Martijn , Eng Stacey , Tirunagari Neeraj , Peng Betty , Yu Mei , Tian Yang , Lee Yu-Jen , Stepan George , Lagpacan Leanna L. , Jin Debi , Hung Magdeleine , Ku Karin S. , Han Bin , Kitrinos Kathryn , Perron Michel , Birkus Gabriel , Wong Kelly A. , Zhong Weidong , Kim Choung U. , Carey Anne , Cho Aesop , Ray Adrian S.
Published: January 2014

As a class, nucleotide inhibitors (NIs) of the hepatitis C virus (HCV) nonstructural protein 5B (NS5B) RNA-dependent RNA polymerase offer advantages over other direct-acting antivirals, including properties, such as pangenotype activity, a high barrier to resistance, and reduced potential for drug-drug interactions. We studied the
in vitro
pharmacology of a novel
C
-nucleoside adenosine analog monophosphate prodrug, GS-6620. It was found to be a potent and selective HCV inhibitor against HCV replicons of genotypes 1 to 6 and against an infectious genotype 2a virus (50% effective concentration [EC
50
], 0.048 to 0.68 μM). GS-6620 showed limited activities against other viruses, maintaining only some of its activity against the closely related bovine viral diarrhea virus (EC
50
, 1.5 μM). The active 5′-triphosphate metabolite of GS-6620 is a chain terminator of viral RNA synthesis and a competitive inhibitor of NS5B-catalyzed ATP incorporation, with

K
i

/

K
m

values of 0.23 and 0.18 for HCV NS5B genotypes 1b and 2a, respectively. With its unique dual substitutions of 1′-CN and 2′-
C
-Me on the ribose ring, the active triphosphate metabolite was found to have enhanced selectivity for the HCV NS5B polymerase over host RNA polymerases. GS-6620 demonstrated a high barrier to resistance
in vitro
. Prolonged passaging resulted in the selection of the S282T mutation in NS5B that was found to be resistant in both cellular and enzymatic assays (>30-fold). Consistent with its
in vitro
profile, GS-6620 exhibited the potential for potent anti-HCV activity in a proof-of-concept clinical trial, but its utility was limited by the requirement of high dose levels and pharmacokinetic and pharmacodynamic variability.
Multilaboratory Study of Epidemiological Cutoff Values for Detection of Resistance in Eight Candida Species to Fluconazole, Posaconazole, and Voriconazole
Authors: Espinel-Ingroff A. , Pfaller M. A. , Bustamante B. , Canton E. , Fothergill A. , Fuller J. , Gonzalez G. M. , Lass-Flörl C. , Lockhart S. R. , Martin-Mazuelos E. , Meis J. F. , Melhem M. S. C. , Ostrosky-Zeichner L. , Pelaez T. , Szeszs M. W. , St-Germain G. , Bonfietti L. X. , Guarro J. , Turnidge J.
Published: January 2014

Although epidemiological cutoff values (ECVs) have been established forCandidaspp. and the triazoles, they are based on MIC data from a single laboratory. We have established ECVs for eightCandidaspecies and fluconazole, posaconazole, and voriconazole based on wild-type (WT) MIC distributions for isolates ofC. albicans(n= 11,241 isolates),C. glabrata(7,538),C. parapsilosis(6,023),C. tropicalis(3,748),C. krusei(1,073),C. lusitaniae(574),C. guilliermondii(373), andC. dubliniensis(162). The 24-h CLSI broth microdilution MICs were collated from multiple laboratories (in Canada, Brazil, Europe, Mexico, Peru, and the United States). The ECVs for distributions originating from ≥6 laboratories, which included ≥95% of the modeled WT population, for fluconazole, posaconazole, and voriconazole were, respectively, 0.5, 0.06 and 0.03 μg/ml forC. albicans, 0.5, 0.25, and 0.03 μg/ml forC. dubliniensis, 8, 1, and 0.25 μg/ml forC. glabrata, 8, 0.5, and 0.12 μg/ml forC. guilliermondii, 32, 0.5, and 0.25 μg/ml forC. krusei, 1, 0.06, and 0.06 μg/ml forC. lusitaniae, 1, 0.25, and 0.03 μg/ml forC. parapsilosis, and 1, 0.12, and 0.06 μg/ml forC. tropicalis. The low number of MICs (<100) for other less prevalent species (C. famata,C. kefyr,C. orthopsilosis,C. rugosa) precluded ECV definition, but their MIC distributions are documented. Evaluation of our ECVs for some species/agent combinations using published individual MICs for 136 isolates (harboring mutations in or upregulation ofERG11,MDR1,CDR1, orCDR2) and 64 WT isolates indicated that our ECVs may be useful in distinguishing WT from non-WT isolates.
Serum-Mediated Activation of Macrophages Reflects TcVac2 Vaccine Efficacy against Chagas Disease
Authors: Gupta Shivali , Silva Trevor S. , Osizugbo Jessica E. , Tucker Laura , Spratt Heidi M. , Garg Nisha J.
Published: January 2014

Chagas disease is endemic in Latin America and an emerging infectious disease in the United States. No effective treatments are available. The TcG1, TcG2, and TcG4 antigens are highly conserved in clinically relevantTrypanosoma cruziisolates and are recognized by B and T cells in infected hosts. Delivery of these antigens as a DNA prime/protein boost vaccine (TcVac2) elicited lytic antibodies and type 1 CD8+T cells that expanded upon challenge infection and provided >90% control of parasite burden and myocarditis in chagasic mice. Here we determined if peripheral blood can be utilized to capture the TcVac2-induced protection from Chagas disease. We evaluated the serum levels ofT. cruzikinetoplast DNA (TckDNA),T. cruzi18S ribosomal DNA (Tc18SrDNA), and murine mitochondrial DNA (mtDNA) as indicators of parasite persistence and tissue damage and monitored the effect of sera on macrophage phenotype. CirculatingTckDNA/Tc18SrDNA and mtDNA were decreased by >3- to 5-fold and 2-fold, respectively, in vaccinated infected mice compared to nonvaccinated infected mice. Macrophages incubated with sera from vaccinated infected mice exhibited M2 surface markers (CD16, CD32, CD200, and CD206), moderate proliferation, a low oxidative/nitrosative burst, and a regulatory/anti-inflammatory cytokine response (interleukin-4 [IL-4] plus IL-10 > tumor necrosis factor alpha [TNF-α]). In comparison, macrophages incubated with sera from nonvaccinated infected mice exhibited M1 surface markers, vigorous proliferation, a substantial oxidative/nitrosative burst, and a proinflammatory cytokine response (TNF-α ≫ IL-4 plus IL-10). Cardiac infiltration of macrophages and TNF-α and oxidant levels were significantly reduced in TcVac2-immunized chagasic mice. We conclude that circulatingTcDNA and mtDNA levels and macrophage phenotype mediated by serum constituents reflectin vivolevels of parasite persistence, tissue damage, and inflammatory/anti-inflammatory state and have potential utility in evaluating disease severity and efficacy of vaccines and drug therapies.
Neutrophils Are a Source of Gamma Interferon during Acute Salmonella enterica Serovar Typhimurium Colitis
Authors: Spees Alanna M. , Kingsbury Dawn D. , Wangdi Tamding , Xavier Mariana N. , Tsolis Renée M. , Bäumler Andreas J.
Published: January 2014

Gamma interferon (IFN-γ) is an important driver of intestinal inflammation during colitis caused bySalmonella entericaserovar Typhimurium. Here we used the mouse colitis model to investigate the cellular sources of IFN-γ in the cecal mucosa during the acute phase of anS. Typhimurium infection. While IFN-γ staining was detected in T cells, NK cells, and inflammatory monocytes at 2 days after infection, the majority of IFN-γ-positive cells in the cecal mucosa were neutrophils. Furthermore, neutrophil depletion blunted mucosalIfngexpression and reduced the severity of intestinal lesions duringS. Typhimurium infection. We conclude that neutrophils are a prominent cellular source of IFN-γ during the innate phase ofS. Typhimurium-induced colitis.
Specialized Science
Authors: Casadevall Arturo , Fang Ferric C.
Published: January 2014

As the body of scientific knowledge in a discipline increases, there is pressure for specialization. Fields spawn subfields that then become entities in themselves that promote further specialization. The process by which scientists join specialized groups has remarkable similarities to the guild system of the middle ages. The advantages of specialization of science include efficiency, the establishment of normative standards, and the potential for greater rigor in experimental research. However, specialization also carries risks of monopoly, monotony, and isolation. The current tendency to judge scientific work by the impact factor of the journal in which it is published may have roots in overspecialization, as scientists are less able to critically evaluate work outside their field than before. Scientists in particular define themselves through group identity and adopt practices that conform to the expectations and dynamics of such groups. As part of our continuing analysis of issues confronting contemporary science, we analyze the emergence and consequences of specialization in science, with a particular emphasis on microbiology, a field highly vulnerable to balkanization along microbial phylogenetic boundaries, and suggest that specialization carries significant costs. We propose measures to mitigate the detrimental effects of scientific specialism.
The association between hospitalisation for childhood head injury and academic performance: evidence from a population e-cohort study
Authors: Gabbe Belinda J , Brooks Caroline , Demmler Joanne C , Macey Steven , Hyatt Melanie A , Lyons Ronan A
Published: January 2014

Background

Childhood head injury has the potential for lifelong disability and burden. This study aimed to establish the association between admission to hospital for childhood head injury and early academic performance.

Methods

The Wales Electronic Cohort for Children (WECC) study is comprised of record-linked routinely collected data, on all children born or residing in Wales. Anonymous linking fields are used to link child and maternal health, environment and education records. Data from WECC were extracted for children born between September 1998 and August 2001. A Generalised Estimating Equation model, adjusted for clustering based on the maternal identifier as well as other key confounders, was used to establish the association between childhood head injury and performance on the Key Stage 1 (KS1) National Curriculum assessment administered to children aged 5–7 years. Head injury was defined as an emergency admission for >24 h for concussion, skull fracture or intracranial injury prior to KS1 assessment.

Results

Of the 101 892 eligible children, KS1 results were available for 90 661 (89%), and 290 had sustained a head injury. Children who sustained an intracranial injury demonstrated significantly lower adjusted odds of achieving a satisfactory KS1 result than children who had not been admitted to hospital for head injury (adjusted OR 0.46, 95% CI 0.30 to 0.72).

Conclusions

The findings of this population e-cohort study quantify the impact of head injury on academic performance, highlighting the need for enhanced head injury prevention strategies. The results have implications for the care and rehabilitation of children admitted to hospital with head injury.
Ground motions selection and scaling for nonlinear dynamic analysis of structures located in Eastern North America
Authors: Michaud Dominic , Léger Pierre
Published: January 2014

This paper presents the effectiveness of seven ground motion scaling methods and two spectral matching methods to achieve compatibility with the Canadian National Building Code (CNBC) 2005 uniform hazard spectrum for Montreal to perform nonlinear seismic analysis. Databases of 30 historical records and 30 Eastern North America simulated records have been selected to compute the reference mean seismic demand and its dispersion. The characteristics and destructive capacity of ground motions have been studied using a large number of indices computed from (i) the records themselves, (ii) a series of single degree of freedom structures, as well as (iii) a four-story steel frame. Record scaling methods to the target spectrum using (i) spectral intensity, (ii) reducing the mean square error, (iii) and minimizing dispersion as well as time domain spectral matching generated coherent seismic demand and dispersion in agreement with the reference values. Spectral matching to a specified elastic design spectrum does not reduce the dispersion of the nonlinear response. Therefore close spectral matching cannot be used to reduce the number of records to minimize the resources allocated in seismic safety assessment. At least seven records, as recommended in current CNBC and FEMA (2012) guidelines to compute an average response, should be used to characterize the nonlinear behaviour of structural systems.
Methylmercury biogeochemistry: a review with special reference to Arctic aquatic ecosystems
Authors: Lehnherr Igor
Published: January 2014

There has been increasing concern about mercury (Hg) levels in marine and freshwater organisms in the Arctic, due to the importance of traditional country foods such as fish and marine mammals to the diet of Northern Peoples. Due to its toxicity and ability to bioaccumulate and biomagnify in food webs, methylmercury (MeHg) is the form of Hg that is of greatest concern. The main sources of MeHg to Arctic aquatic ecosystems, the processes responsible for MeHg formation and degradation in the environment, MeHg bioaccumulation in Arctic biota and the human health implications for Northern Peoples are reviewed here. In Arctic marine ecosystems, Hg(II) methylation in the water column, rather than bottom sediments, is the primary source of MeHg, although a more quantitative understanding of the role of dimethylmercury (DMHg) as a MeHg source is needed. Because MeHg production in marine waters is limited by the availability of Hg(II), predicted increases in Hg(II) concentrations in oceans are likely to result in higher MeHg concentrations and increased exposure to Hg in humans and wildlife. In Arctic freshwaters, MeHg concentrations are a function of two antagonistic processes, net Hg(II) methylation in bottom sediments of ponds and lakes and MeHg photodemethylation in the water column. Hg(II) methylation is controlled by microbial activity and Hg(II) bioavailability, which in turn depend on interacting environmental factors (temperature, redox conditions, organic carbon, and sulfate) that induce nonlinear responses in MeHg production. Methylmercury bioaccumulation–biomagnification in Arctic aquatic food webs is a function of the MeHg reservoir in abiotic compartments, as well as ecological considerations such as food-chain length, growth rates, life-history characteristics, feeding behavior, and trophic interactions. Methylmercury concentrations in Arctic biota have increased significantly since the onset of the industrial age, and in some populations of fish, seabirds, and marine mammals toxicological thresholds are being exceeded. Due to the complex connection between Hg exposure and human health in Northern Peoples—arising from the dual role of country foods as both a potential Hg source and a nutritious, affordable food source with many physical and social health benefits—-reductions in anthropogenic Hg emissions are seen as the only viable long-term solution.
TENTH-ORDER QED CONTRIBUTION TO THE ELECTRON g-2 AND HIGH PRECISION TEST OF QUANTUM ELECTRODYNAMICS
Authors: KINOSHITA TOICHIRO
Published: January 2014

This paper presents the current status of the theory of electron anomalous magnetic moment ae ≡(g-2)/2, including a complete evaluation of 12,672 Feynman diagrams in the tenth-order perturbation theory. To solve this problem, we developed a code-generator which converts Feynman diagrams automatically into fully renormalized Feynman-parametric integrals. They are evaluated numerically by an integration routine VEGAS. The preliminary result obtained thus far is 9.16 (58) (α/π)5, where (58) denotes the uncertainty in the last two digits. This leads to ae( theory ) = 1.159 652 181 78 (77) ×10-3, which is in agreement with the latest measurement ae ( exp :2008) = 1.159 652 180 73 (28) ×10-3. It shows that the Feynman–Dyson method of perturbative QED works up to the precision of 10-12.
EFFECT OF HARVESTING AND PREY REFUGE IN A PREY–PREDATOR SYSTEM
Authors: LV YUNFEI , ZHANG ZHENGYANG , YUAN RONG , PEI YONGZHEN
Published: January 2014

Considering that the ecological system is often deeply perturbed by human exploiting activities, this paper deals with a prey–predator model with prey refuge in which both species are independently harvested. First, some sufficient conditions for global stability of equilibria are obtained, and the existence and uniqueness of limit cycles are established. Our results indicate that over-exploitation would result in the extinction of the population and an appropriate harvesting strategy should ensure the sustainability of the population, which is in line with reality. Furthermore, the existence of bionomic equilibrium is discussed. Finally, the influences of prey refuge and harvesting efforts on equilibrium density values are considered and some numerical simulations are given to illustrate our results.
AVIAN FLU: MODELING AND IMPLICATIONS FOR CONTROL
Authors: MARTCHEVA MAIA
Published: January 2014

At present, H5N1 avian influenza (AI) is a zoonotic disease where the transmission to humans occurs from infected domestic birds. Since 2003, more than 500 people have been infected and nearly 60% of them have died. If the H5N1 virus becomes efficiently human-to-human transmittable, a pandemic will occur with potentially high mortality. A mathematical model of AI, which involves human influenza, is introduced to better understand the complex epidemiology of AI and the emergence of a pandemic strain. Demographic and epidemiological data on birds and humans are used for the parameterization of the model. The differential equation system faithfully projects the cumulative number of H5N1 human cases and captures the dynamics of the yearly cases. The model is used to rank the efficacy of the current control measures used to prevent the emergence of a pandemic strain. We find that culling without re-population and vaccination are the two most efficient control measures each giving 22% decrease in the number of H5N1 infected humans for each 1% change in the affected parameters (μb, νb for culling and βb, νb for vaccination). Control measures applied to humans, such as wearing protective gear, are not very efficient, giving less than 1% decrease in the number of H5N1 infected humans for each 1% decrease in βY, the bird-to-human transmission coefficient of H5N1. Furthermore, we find that should a pandemic strain emerge, it will invade, possibly displacing the human influenza virus in circulation at that time. Moreover, higher prevalence levels of human influenza will obstruct the invasion capabilities of the pandemic H5N1 strain. This effect is not very pronounced, as we find that 1% increase in human influenza prevalence will decrease the invasion capabilities of the pandemic strain with 0.006%.
NUMERICAL SIMULATION OF RAYLEIGH–TAYLOR INSTABILITY BASED ON AN IMPROVED PARTICLE LEVEL SET METHOD
Authors: TIAN HUI , LI GUOJUN , ZHANG XIONGWEN
Published: January 2014

An improved particle correction procedure for particle level set method is proposed and applied to the simulation of Rayleigh–Taylor instability (RTI) of the incompressible two-phase immiscible fluids. In the proposed method, an improved particle correction method is developed to deal with all the relative positions between escaped particles and cell corners, which can reduce the disturbance arising in the distance function correction process due to the non-normal direction movement of escaped particles. The improved method is validated through accurately capturing the moving interface of the Zalesak's disk. Furthermore, coupled with the projection method for solving the Navier–Stokes equations, the time-dependent evolution of the RTI interface over a wide range of Reynolds numbers, Atwood numbers and Weber numbers are numerically investigated. A good agreement between the present results and the existing analytical solutions is obtained and the accuracy of the proposed method is further verified. Moreover, the effects of control parameters including viscosity, density ratio, and surface tension coefficient on the evolution of RTI are analyzed in detail, and a critical Weber number for the development of RTI is found.
FIRST MEASUREMENTS OF THE ρ3 SPIN DENSITY MATRIX ELEMENTS IN γp → pω USING CLAS AT JLAB
Authors:   (for the CLAS Collaboration), VERNARSKY BRIAN
Published: January 2014

In an effort towards a "complete" experiment for the ω meson, we present studies from an experiment with an unpolarized target and a circularly polarized photon beam (g1c), carried out using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. The experiment was analyzed using an extended maximum likelihood fit with partial wave amplitudes. New likelihood functions were calculated to account for the polarization of the photon beam. Both circular and linear polarizations are explored. The results of these fits are then used to project out the spin density matrix for the ω. First measurements of the ρ3 spin density matrix elements will be presented using this method.
NUCLEON RESONANCES AND GPDS IN AdS/QCD
Authors: VEGA ALFREDO , SCHMIDT IVAN , GUTSCHE THOMAS , LYUBOVITSKIJ VALERY E.
Published: January 2014

We discuss an holographic soft wall model to describe nucleon properties. We pay special attention to nucleon spectrum, GPDs in the skewness case for nucleons and electroproduction of the N (1440) Roper resonance in soft-wall AdS/QCD.
MEASUREMENTS OF SPIN OBSERVABLES IN PSEUDOSCALAR-MESON PHOTOPRODUCTION USING POLARIZED NEUTRONS IN SOLID HD
Authors:   (On behalf of CLAS collaboration), KAGEYA TSUNEO
Published: January 2014

Psuedo-scalar meson photo production measurements have been carried out with longitudinally-polarized neutrons using the circularly and linearly polarized photon beams and the CLAS at Thomas Jefferson National Accelerator Facility (Jlab). The experiment aims to obtain a complete set of spin observables on an efficient neutron target. Preliminary E asymmetries for the exclusive reaction, γ + n(p) → π- + p(p), selecting quasi free neutron kinematics are discussed.
BONN-GATCHINA ANALYSIS: DEVELOPMENT OF THE METHOD AND ANALYSIS OF NEW PHOTO-PRODUCTION DATA
Authors: SARANTSEV A.
Published: January 2014

The new method for a combined analysis of meson production data is presented. This method fully satisfies the unitarity and analyticity conditions and is suitable for an analysis of modern high statistic data. The results obtained in the framework of this approach are compared with the results of the K-matrix analysis. Including in the analysis of the meson production reaction the data from the γ-neutron collision allows us to extract the information about the helicity couplings [Formula: see text] and [Formula: see text] of nucleon states.
THE NUCLEON MASS AND PION-NUCLEON SIGMA TERM FROM A CHIRAL ANALYSIS OF Nf = 2 + 1 LATTICE QCD WORLD DATA
Authors: ALVAREZ-RUSO L. , LEDWIG T. , VICENTE VACAS M. J. , MARTIN-CAMALICH J.
Published: January 2014

Fits of the p4 covariant SU(2) baryon chiral perturbation theory to lattice QCD nucleon mass data from several collaborations for 2 and 2+1 flavors are presented. We consider contributions from explicit Δ(1232) degrees of freedom, finite volume and finite spacing corrections. We emphasize here on our Nf = 2 + 1 study. We obtain low-energy constants of natural size that are compatible with the rather linear pion-mass dependence of the nucleon mass observed in lattice QCD. We report a value of σπN = 41(5)(4) MeV in the 2 flavor case and σπN = 52(3)(8) MeV for 2+1 flavors.
LATEST RESULTS FROM BESIII
Authors:   (on behalf of the BESIII collaboration), LIANG YUTIE
Published: January 2014

Recent results of the BESIII experiment are presented, including the first observation of the M1 transition ψ(3686) → γηc(2S), the measurement of J/ψ → 3γ, ηc decays into baryon anti-baryon pairs, the discovery of Zc(3900), and the study of [Formula: see text].
ISSUES OF EFFECTIVE FIELD THEORIES WITH RESONANCES
Authors: GEGELIA JAMBUL , JAPARIDZE GEORGE
Published: January 2014

We address some issues of renormalization and symmetries of effective field theories with unstable particles - resonances. We also calculate anomalous contributions in the divergence of the singlet axial current in an effective field theory of massive SU(N) Yang-Mills fields interacting with fermions and discuss their possible relevance to the strong CP problem.
NEW INSIGHTS IN $\bar{K}N$ SCATTERING AND THE Λ(1405)
Authors: OLLER J. A.
Published: January 2014

We discuss in this talk aspects of [Formula: see text] plus coupled channels dynamics with special emphasis on the Λ(1405) resonance and isovector resonances in the same energy region. We comment on several experimental reactions giving rise to πΣ distributions with important implications on the spectroscopy. We also discuss recent theoretical models based con NLO SU(3) unitarized chiral perturbation theory.
POLARIZATION OBSERVABLES FOR K+Λ AND K+Σ0 PHOTOPRODUCTION FROM POLARIZED PROTONS
Authors:   (for the CLAS Collaboration), WALFORD NATALIE K. , KLEIN FRANZ J.
Published: January 2014

The search for undiscovered excited states of the nucleon continues to be a focus of experiments at Jefferson Lab. Recent LQCD calculations have confirmed long-standing quark-model predictions of many more states than have so far been identified.1 A large effort for the N* program has been launched using the CLAS detector to provide the database that will allow nearly model-independent partial wave analyses to be carried out in the search for such states. Polarization observables play a crucial role in this effort, as they are essential in disentangling overlapping resonant and non-resonant amplitudes. In 2010, double-polarization data were taken at JLab using circularly polarized photons incident on a transversely polarized frozen-spin butanol target.2 Our current analysis yields preliminary data of the T and F asymmetries of the K+Λ and K+Σ0 final states, which are compared to predictions of recent multipole analyses. This work is the first of its kind and will significantly broaden the world database for these reactions.
RESONANCE PRODUCTION AND DECAY IN PROTON-PROTON COLLISIONS AT T = 1.25 GeV MEASURED WITH HADES SPECTROMETER
Authors:   (for the HADES Collaboration), PRZYGODA W.
Published: January 2014

In this paper we report on the investigation of baryonic resonance production in proton-proton collisions at kinetic energy 1.25 GeV measured with HADES. Exclusive channels ppe+e- and ppe+e-γ as well as ppπ0 and npπ+ were studied. The resonance cross section was determined from hadronic channels in the framework of a one boson exchange model with the accuracy of 15%. The dilepton analysis proved the resonance origin of e+e- pairs and the Δ Dalitz decay was identified experimentally (in the pe+e- channel) for the first time. Investigation of hadronic reaction channels by means of the Partial Wave Analysis revealed a dominant contribution of P33(1232) but also sizeable non-resonant terms and interference effects.
N AND Δ HIDDEN-CHARM RESONANCES WITH HEAVY-QUARK SPIN SYMMETRY
Authors: ROMANETS OLENA , GARCÍA-RECIO CARMEN , SALCEDO LORENZO LUIS , NIEVES JUAN , TOLÓS LAURA
Published: January 2014

We study N and Δ hidden-charm baryon resonances that are generated dynamically from the s-wave interaction of pseudoscalar and vector mesons with 1/2+ and 3/2+ baryons. We use a unitary coupled-channels model that fulfills heavy-quark spin symmetry and respects spin-flavor symmetry in the light sector. We predict seven N-like and five Δ-like states with masses around 4 GeV, most of them as bound states. Some of these states form heavy-quark spin multiplets, which are almost degenerate in mass.
STUDY OF EXCITED NUCLEONS IN $\psi(3686)\to p\overline p \pi^0, p \overline p \eta$
Authors:   (on behalf of the BESIII collaboration), YUAN WENLONG
Published: January 2014

Based on 106×106 ψ(3686) events collected with BESIII at BEPCII, partial wave analysis (PWA) of [Formula: see text] and [Formula: see text] are performed. Clear signals for N(1535) are observed and the mass, width and spin-parity are measured from [Formula: see text]. 7 N* intermediate resonances including two significant new resonances N(2300) and N(2570) are observed and the mass, width and spin-parity are also measured from [Formula: see text].
TENSILE PROPERTIES OF GRAPHENE-NANOTUBE HYBRID STRUCTURES: A MOLECULAR DYNAMICS STUDY
Authors: ZHAN H. F. , XIA K. , GU Y. T.
Published: January 2014

Graphene has been reported with record-breaking properties which have opened up huge potential applications. A considerable research has been devoted to manipulate or modify the properties of graphene to target a more smart nanoscale device. Graphene and carbon nanotube hybrid structure (GNHS) is one of the promising graphene derivative, whose mechanical properties have been rarely discussed in literature. Therefore, the mechanical properties of GNHS is studied in this paper based on the large-scale molecular dynamics simulation. The target GNHS is constructed by considering two separate graphene layers that are being connected by single-wall carbon nanotubes (SWCNTs) according to the experimental observations. It is found that the GNHSs exhibit much lower yield strength, Young's modulus, and earlier yielding compared to bilayer graphene sheet. Fracture of GNHSs is found to initiate at the connecting region between carbon nanotubes (CNTs) and graphene. After failure, monatomic chains are normally observed at the front of the failure region, and the two graphene layers at the failure region without connecting CNTs will adhere to each other, generating a bilayer graphene sheet scheme (with a layer distance about 3.4 Å). This study will enrich the current understanding of the mechanical performance of GNHS, which will guide the design of GNHS and shed light on its various applications.
Integrating Task and Motion Planning for Unmanned Aerial Vehicles
Authors: Cons Matthew S. , Shima Tal , Domshlak Carmel
Published: January 2014

This paper investigates the problem where a fixed-winged unmanned aerial vehicle is required to find the shortest flyable path to traverse over multiple targets. The unmanned aerial vehicle is modeled as a Dubins vehicle: a vehicle with a minimum turn radius and the inability to go backward. This problem is called the Dubins traveling salesman problem, an extension of the well-known traveling salesman problem. We propose and compare different algorithms that integrate the task planning and the motion planning aspects of the problem, rather than treating the two separately. An upper bound on calculating kinematic satisfying paths for setting costs in the search algorithm is investigated. The proposed integrated algorithms are compared to hierarchical algorithms that solve the search aspect first and then solve the motion planning aspect second. Monte Carlo simulations are performed for a range of vehicle turn radii. The simulations results show the viability of the integrated approach and that using two plausible kinematic satisfying paths as an upper bound to determine the cost-so-far into a search algorithm generally improves performance in terms of the shortest path cost and search complexity.
Recovery modeling of negative bias temperature instability (NBTI) for SPICE-compatible circuit aging simulators
Authors: Küflüoğlu Haldun , Chancellor Cathy , Chen Min , Cirba Claude , Reddy Vijay
Published: January 2014

A feasible computational framework that enables improved predictability of NBTI degradation within commercially available tools is discussed. The NBTI model is used for real-time circuit operation where recovery is present. The complementary nature of implementation is readily incorporated into existing model extraction and verification tools. The method provides significantly enhanced accuracy in simulations when compared to circuit data, yet retains practicality and flexibility.
Selecting representative benchmark inputs for exploring microprocessor design spaces
Authors: Breughe Maximilien B. , Eeckhout Lieven
Published: January 2014

The design process of a microprocessor requires representative workloads to steer the search process toward an optimum design point for the target application domain. However, considering a broad set of workloads to cover the large space of potential workloads is infeasible given how time-consuming design space exploration typically is. Hence, it is crucial to select a small yet representative set of workloads, which leads to a shorter design cycle while yielding a (near) optimal design.

Prior work has mostly looked into selecting representative benchmarks; however, limited attention was given to the selection of benchmark
inputs
and how this affects workload representativeness during design space exploration. Using a set of 1,000 inputs for a number of embedded benchmarks and a design space with around 1,700 design points, we find that selecting a single or three random input(s) per benchmark potentially (in a worst-case scenario) leads to a suboptimal design that is 56% and 33% off, on average, relative to the optimal design in our design space in terms of Energy-Delay Product (EDP). We then propose and evaluate a number of methods for selecting representative inputs and show that we can find the optimum design point with as few as three inputs.
HPar
Authors: Zhao Zhijia , Bebenita Michael , Herman Dave , Sun Jianhua , Shen Xipeng
Published: January 2014

Parallelizing HTML parsing is challenging due to the complexities of HTML documents and the inherent dependencies in its parsing algorithm. As a result, despite numerous studies in parallel parsing, HTML parsing remains sequential today. It forms one of the final barriers for fully parallelizing browser operations to minimize the browser’s response time—an important variable for user experiences, especially on portable devices. This article provides a comprehensive analysis on the special complexities of parallel HTML parsing and presents a systematic exploration in overcoming those difficulties through specially designed speculative parallelizations. This work develops, to the best of our knowledge, the first pipelining and data-level parallel HTML parsers. The data-level parallel parser, named
HPar
, achieves up to 2.4× speedup on quadcore devices. This work demonstrates the feasibility of efficient, parallel HTML parsing for the first time and offers a set of novel insights for parallel HTML parsing
Easy, fast, and energy-efficient object detection on heterogeneous on-chip architectures
Authors: Totoni Ehsan , Dikmen Mert , Garzarán María Jesús
Published: January 2014

We optimize a visual object detection application (that uses Vision Video Library kernels) and show that OpenCL is a unified programming paradigm that can provide high performance when running on the Ivy Bridge heterogeneous on-chip architecture. We evaluate different mapping techniques and show that running each kernel where it fits the best and using software pipelining can provide 1.91 times higher performance and 42% better energy efficiency. We also show how to trade accuracy for energy at runtime. Overall, our application can perform accurate object detection at 40 frames per second (fps) in an energy-efficient manner.
Profile-guided transaction coalescing—lowering transactional overheads by merging transactions
Authors: Stipić Srđan , Smiljković Vesna , Unsal Osman , Cristal Adrián , Valero Mateo
Published: January 2014

Previous studies in software transactional memory mostly focused on reducing the overhead of transactional read and write operations. In this article, we introduce
transaction coalescing
, a profile-guided compiler optimization technique that attempts to reduce the overheads of starting and committing a transaction by merging two or more small transactions into one large transaction. We develop a profiling tool and a transaction coalescing heuristic to identify candidate transactions suitable for coalescing. We implement a compiler extension to automatically merge the candidate transactions at the compile time. We evaluate the effectiveness of our technique using the hash table micro-benchmark and the STAMP benchmark suite. Transaction coalescing improves the performance of the hash table significantly and the performance of Vacation and SSCA2 benchmarks by 19.4% and 36.4%, respectively, when running with 12 threads.
Beyond reuse distance analysis
Authors: Fauzia Naznin , Elango Venmugil , Ravishankar Mahesh , Ramanujam J. , Rastello Fabrice , Rountev Atanas , Pouchet Louis-Noël , Sadayappan P.
Published: January 2014

Emerging computer architectures will feature drastically decreased flops/byte (ratio of peak processing rate to memory bandwidth) as highlighted by recent studies on Exascale architectural trends. Further, flops are getting cheaper, while the energy cost of data movement is increasingly dominant. The understanding and characterization of data locality properties of computations is critical in order to guide efforts to enhance data locality.

Reuse distance analysis of memory address traces is a valuable tool to perform data locality characterization of programs. A single reuse distance analysis can be used to estimate the number of cache misses in a fully associative LRU cache of any size, thereby providing estimates on the minimum bandwidth requirements at different levels of the memory hierarchy to avoid being bandwidth bound. However, such an analysis only holds for the particular execution order that produced the trace. It cannot estimate potential improvement in data locality through dependence-preserving transformations that change the execution schedule of the operations in the computation.

In this article, we develop a novel dynamic analysis approach to characterize the inherent locality properties of a computation and thereby assess the potential for data locality enhancement via dependence-preserving transformations. The execution trace of a code is analyzed to extract a Computational-Directed Acyclic Graph (CDAG) of the data dependences. The CDAG is then partitioned into convex subsets, and the convex partitioning is used to reorder the operations in the execution trace to enhance data locality. The approach enables us to go beyond reuse distance analysis of a single specific order of execution of the operations of a computation in characterization of its data locality properties. It can serve a valuable role in identifying promising code regions for manual transformation, as well as assessing the effectiveness of compiler transformations for data locality enhancement. We demonstrate the effectiveness of the approach using a number of benchmarks, including case studies where the potential shown by the analysis is exploited to achieve lower data movement costs and better performance.
Designing a practical data filter cache to improve both energy efficiency and performance
Authors: Bardizbanyan Alen , Själander Magnus , Whalley David , Larsson-Edefors Per
Published: January 2014

Conventional Data Filter Cache (DFC) designs improve processor energy efficiency, but degrade performance. Furthermore, the single-cycle line transfer suggested in prior studies adversely affects Level-1 Data Cache (L1 DC) area and energy efficiency. We propose a practical DFC that is accessed early in the pipeline and transfers a line over multiple cycles. Our DFC design improves performance and eliminates a substantial fraction of L1 DC accesses for loads, L1 DC tag checks on stores, and data translation lookaside buffer accesses for both loads and stores. Our evaluation shows that the proposed DFC can reduce the data access energy by 42.5% and improve execution time by 4.2%.
A system architecture, processor, and communication protocol for secure implants
Authors: Strydis Christos , Seepers Robert M. , Peris-Lopez Pedro , Siskos Dimitrios , Sourdis Ioannis
Published: January 2014

Secure and energy-efficient communication between Implantable Medical Devices (IMDs) and authorized external users is attracting increasing attention these days. However, there currently exists no systematic approach to the problem, while solutions from neighboring fields, such as wireless sensor networks, are not directly transferable due to the peculiarities of the IMD domain. This work describes an original, efficient solution for secure IMD communication. A new implant system architecture is proposed, where security and main-implant functionality are made completely decoupled by running the tasks onto two separate cores. Wireless communication goes through a custom security ASIP, called SISC (Smart-Implant Security Core), which runs an energy-efficient security protocol. The security core is powered by RF-harvested energy until it performs external-reader authentication, providing an elegant defense mechanism against battery Denial-of-Service (DoS) and other, more common attacks. The system has been evaluated based on a realistic case study involving an artificial pancreas implant. When synthesized for a UMC 90nm CMOS ASIC technology, our system architecture achieves defense against unauthorized accesses having
zero energy cost
, running entity authentication through harvesting only 7.45μ
J
of RF energy from the requesting entity. In all other successfully authenticated accesses, our architecture achieves secure data exchange without affecting the performance of the main IMD functionality, adding less than 1‰ (1.3
mJ
) to the daily energy consumption of a typical implant. Compared to a singe-core, secure reference IMD, which would still be more vulnerable to some types of attacks, our secure system on chip (SoC) achieves high security levels at 56% energy savings and at an area overhead of less than 15%.
JIT technology with C/C++
Authors: Nuzman Dorit , Eres Revital , Dyshel Sergei , Zalmanovici Marcel , Castanos Jose
Published: January 2014

The growing gap between the advanced capabilities of static compilers as reflected in benchmarking results and the actual performance that users experience in real-life scenarios makes client-side dynamic optimization technologies imperative to the domain of static languages. Dynamic optimization of software distributed in the form of a platform-agnostic Intermediate-Representation (IR) has been very successful in the domain of managed languages, greatly improving upon interpreted code, especially when online profiling is used. However, can such feedback-directed IR-based dynamic code generation be viable in the domain of statically compiled, rather than interpreted, languages? We show that fat binaries, which combine the IR together with the statically compiled executable, can provide a practical solution for software vendors, allowing their software to be dynamically optimized without the limitation of binary-level approaches, which lack the high-level IR of the program, and without the warm-up costs associated with the IR-only software distribution approach. We describe and evaluate the fat-binary-based runtime compilation approach using SPECint2006, demonstrating that the overheads it incurs are low enough to be successfully surmounted by dynamic optimization. Building on Java JIT technologies, our results already improve upon common real-world usage scenarios, including very small workloads.
Evaluator-executor transformation for efficient pipelining of loops with conditionals
Authors: Jeong Yeonghun , Seo Seongseok , Lee Jongeun
Published: January 2014

Control divergence poses many problems in parallelizing loops. While predicated execution is commonly used to convert control dependence into data dependence, it often incurs high overhead because it allocates resources equally for both branches of a conditional statement regardless of their execution frequencies. For those loops with
unbalanced
conditionals, we propose a software transformation that divides a loop into two or three smaller loops so that the condition is evaluated only in the first loop, while the less frequent branch is executed in the second loop in a way that is much more efficient than in the original loop. To reduce the overhead of extra data transfer caused by the loop fission, we also present a hardware extension for a class of Coarse-Grained Reconfigurable Architectures (CGRAs). Our experiments using MiBench and computer vision benchmarks on a CGRA demonstrate that our techniques can improve the performance of loops over predicated execution by up to 65% (37.5%, on average), when the hardware extension is enabled. Without any hardware modification, our software-only version can improve performance by up to 64% (33%, on average), while simultaneously reducing the energy consumption of the entire CGRA including configuration and data memory by 22%, on average.
A survey of smart data pricing
Authors: Sen Soumya , Joe-Wong Carlee , Ha Sangtae , Chiang Mung
Published: January 2014

Traditionally, network operators have used simple flat-rate broadband data plans for both wired and wireless network access. But today, with the popularity of mobile devices and exponential growth of apps, videos, and clouds, service providers are gradually moving toward more sophisticated pricing schemes. This decade will therefore likely witness a major change in the ways in which network resources are managed, and the role of economics in allocating these resources. This survey reviews some of the well-known past broadband pricing proposals (both static and dynamic), including their current realizations in various consumer data plans around the world, and discusses several research problems and open questions. By exploring the benefits and challenges of pricing data, this article attempts to facilitate both the industrial and the academic communities' efforts in understanding the existing literature, recognizing new trends, and shaping an appropriate and timely research agenda.
From RSSI to CSI
Authors: Yang Zheng , Zhou Zimu , Liu Yunhao
Published: January 2014

The spatial features of emitted wireless signals are the basis of location distinction and determination for wireless indoor localization. Available in mainstream wireless signal measurements, the Received Signal Strength Indicator (RSSI) has been adopted in vast indoor localization systems. However, it suffers from dramatic performance degradation in complex situations due to multipath fading and temporal dynamics.

Break-through techniques resort to finer-grained wireless channel measurement than RSSI. Different from RSSI, the PHY layer power feature, channel response, is able to discriminate multipath characteristics, and thus holds the potential for the convergence of accurate and pervasive indoor localization. Channel State Information (CSI, reflecting channel response in 802.11 a/g/n) has attracted many research efforts and some pioneer works have demonstrated submeter or even centimeter-level accuracy. In this article, we survey this new trend of channel response in localization. The differences between CSI and RSSI are highlighted with respect to network layering, time resolution, frequency resolution, stability, and accessibility. Furthermore, we investigate a large body of recent works and classify them overall into three categories according to how to use CSI. For each category, we emphasize the basic principles and address future directions of research in this new and largely open area.
Survey and analysis of current mobile learning applications and technologies
Authors: Pereira Orlando R. E. , Rodrigues Joel J. P. C.
Published: January 2014

Distance learning, electronic learning, and mobile learning offer content, methods, and technologies that decrease the limitations of traditional education. Mobile learning (m-learning) is an extension of distance education, supported by mobile devices equipped with wireless technologies. It is an emerging learning model and process that requires new forms of teaching, learning, contents, and dynamics between actors. In order to ascertain the current state of knowledge and research, an extensive review of the literature in m-learning has been undertaken to identify and harness potential factors and gaps in implementation. This article provides a critical analysis of m-learning projects and related literature, presenting the findings of this aforementioned analysis. It seeks to facilitate the inquiry into the following question: “What is possible in m-learning using recent technologies?” The analysis will be divided into two main parts: applications from the recent online mobile stores and operating system standalone applications.