bluuebunny/crossref_metadata_2025 huggingface dataset:
Safety and availability of clofazimine in the treatment of multidrug and extensively drug-resistant tuberculosis: analysis of published guidance and meta-analysis of cohort studies
Authors: Hwang Thomas J , Dotsenko Svetlana , Jafarov Azizkhon , Weyer Karin , Falzon Dennis , Lunte Kaspars , Nunn Paul , Jaramillo Ernesto , Keshavjee Salmaan , Wares Douglas F
Published: January 2014

Objectives

Given the spread of multidrug-resistant tuberculosis (MDR-TB), new therapies are urgently needed, including the repurposing of existing drugs. We aimed to assess key considerations for the clinical and programmatic use of clofazimine (Cfz), a riminophenazine with antimycobacterial activity currently used to treat leprosy.

Design

Fixed and random effects meta-analysis of cohort studies and systematic review.

Setting

Electronic and manual searches were combined.

Inclusion criteria

Observational studies on treatment of multidrug-resistant and extremely drug-resistant tuberculosis with Cfz or a Cfz-containing regimen, and published guidance and documents relating to cost and availability were eligible.

Results

5 observational studies enrolled 861 patients, of which 602 received Cfz. The pooled proportion of adverse drug reactions requiring discontinuation of Cfz treatment was 0.1% (95% CI (0.0 to 0.6%)), and the median frequency of all adverse events was 5.1%. Cfz showed in vitro efficacy againstMycobacterium tuberculosis, and Cfz-containing regimens may have had a useful role in the treatment of patients with drug-resistant strains and who had limited alternative treatment options. However, Cfz uptake remains insufficient to meet global needs; there is only one internationally quality-assured manufacturer, which produces a limited quantity of the drug prioritised for treatment of leprosy, the only indication for which the drug is registered.

Conclusions

While the data were limited, Cfz was associated with a risk for adverse drug reactions comparable to that of first-line TB treatment, which could be reasonably managed under programmatic conditions. However, low market availability and high cost are important barriers to access to Cfz for patients with MDR-TB.
Mycorrhizas in changing ecosystems,
Authors: Dickie Ian A. , Koele Nina , Blum Joel D. , Gleason James D. , McGlone Matthew S.
Published: January 2014

Ecosystems change between arbuscular mycorrhizal and ectomycorrhizal vegetation dominance over anthropological and geological time scales, yet consequences for ecosystem function are unclear. We review four hypotheses for the effect of mycorrhizal status on ecosystem function. Specifically, that differences between ectomycorrhizal and arbuscular mycorrhizal dominated ecosystems are driven by (1) foliar trait differences, (2) positive plant–soil feedback in ectomycorrhizal plants, (3) differences in the ability to dissolve rocks as a source of nutrition, and (4) differences in the ability to use organic nutrients. We find no universal difference in foliar traits with mycorrhizal status. A spatial simulation suggests that positive plant–soil feedback in ectomycorrhizal plants is unlikely to drive ecosystem differences. However, negative feedback appears to be more common in arbuscular mycorrhizal trees than ectomycorrhizal trees and may represent an important ecosystem difference. Rock dissolution occurs under both mycorrhizal types but may differ in rate. Hypothesis 4 was the best supported: a model and some field evidence suggest that decoupling of carbon and nutrients in ectomycorrhizal decomposition leads to inhibition of saprotrophic mineralization, with context-dependent effects. Greater understanding of organic nutrient utilization differences may be key to improving incorporation of mycorrhizas in ecosystem ecology.
Sexual dimorphism in leaf nitrogen content but not photosynthetic rates in Sagittaria latifolia (Alismataceae)
Authors: Wright Veronika L. , Dorken Marcel E.
Published: January 2014

Sexual dimorphism in reproductive costs between females and males in dioecious plants is associated with divergent morphologies, life histories, and physiologies between the sexes. In Sagittaria latifolia Willd. (Alismataceae), a previous experiment has shown that sexual reproduction imposes asymmetric costs for females vs. males, with greater biomass costs for females and greater nitrogen costs for males. Here we investigate whether sexual dimorphism in nitrogen expenditure for reproduction influences the nitrogen content of leaves under natural conditions and, if so, whether it is associated with differences in photosynthetic rates between the sexes. As expected, we found significantly lower leaf nitrogen content among males compared with females and a positive association between leaf nitrogen content and photosynthetic rates. However, this difference in nitrogen content between the sexes was not associated with different photosynthetic rates for females vs. males. Our study demonstrates that an underlying difference in nitrogen content between the sexes is maintained during flower and fruit production in a natural population, but, at least at the site used for this study, this difference was not associated with divergent photosynthetic rates.
East-derived strata in the Methow basin record rapid mid-Cretaceous uplift of the southern Coast Mountains batholith
Authors: Surpless Kathleen D. , Sickmann Zachary T. , Koplitz Trevor A.
Published: January 2014

The Jurassic–Cretaceous Methow basin of northern Washington State and southern British Columbia forms an overlap sequence linking several small tectonostratigraphic terranes. Sandstone petrography, sandstone and mudrock geochemistry, and detrital zircon U–Pb age and Hf analysis of mid-Cretaceous, east-derived Methow strata together document a remarkably uniform provenance signature that suggests proximal, abundant, and unchanging sediment sources throughout deposition. The eastern belt of the Coast Mountains batholith, intruded into Stikine and related inboard terranes of the Intermontane superterrane, along with Jurassic and Cretaceous plutons of the westernmost Okanogan Range, provide the best match to the provenance signature of east-derived sediment in the Methow basin during the mid-Cretaceous. Furthermore, the Cretaceous and Jurassic plutons of the eastern Coast Mountains batholith and western Okanogan Range were rapidly uplifted to provide the substantial thickness of sediment in the Methow basin, and they must have acted as a topographic barrier that effectively prevented sediment derived from the continental interior from reaching the basin. This uplift of a proximal eastern source occurred during regional late Early Cretaceous sinistral transpression and resulted in subsidence of the Methow trough and rapid deposition of east-derived strata in the Methow basin. Because Methow sediment sources apparently did not include the North American interior, the extent of post-depositional large-scale translation relative to the North American craton of the Methow basin with its proximal, eastern sources cannot be unequivocally determined.
John Tuzo Wilson: a man who moved mountains
Authors: West Gordon F. , Farquhar Ron M. , Garland George D. , Halls Henry C. , Morley Lawrence W. , Russell R. Don
Published: January 2014

Fifty years ago, the world’s Earth Scientists experienced the so-called “Revolution in the Earth Sciences”. In the decade from 1960 to 1970, a massive convergence took place from many diverse and contradictory theories about the tectonic processes operating on Earth (then loosely called “mountain building”) to a single widely accepted paradigm now called Plate Tectonics. A major player in leading the international “Revolution” was Canadian geophysicist J. Tuzo Wilson. This tribute reviews how he helped define and promote the Plate Tectonic paradigm, and also, from 1946 to 1967, how he led a rapid expansion of the role of geophysics in Canadian and international earth science. Wilson was a controversial figure before and during the “Revolution”, but his influence was large. It was not coincidental that earth science research in Canada grew by 1964 to the point where the National Research Council of Canada could add the Canadian Journal of Earth Sciences to its group of Canadian research journals.
Robust fixed-count density estimation with virtual plots
Authors: Magnussen Steen
Published: January 2014

Fixed-count sampling (plotless) remains attractive for forest inventories in difficult terrains and for their control of the number (k) of trees to measure. Although recent fixed-count estimators of density (PDE) are less biased than older ones, the risk of a nontrivial bias remains a deterrent. A recently published PDE based on a generic algorithm for predicting distances to the k + m nearest tree (m = 1, 2, ...) has attractive properties in terms of average bias and average root mean squared errors across a wide spectrum of spatial point patterns. However, the risk of a sizeable bias remains an issue. Sensitivity to spatial patterns is seen as its main weakness. It is hypothesized that a new PDE with robust properties will mitigate the bias issue and encourage wider use. To this end, a new PDE estimator is proposed. It builds on a mixture of observed and predicted distances to a set of k + m nearest trees to generate counts of actual and virtual trees inside a circle with a data-driven fixed radius. The proposed new robust fixed-count density estimator achieved an average absolute bias of 1.2% when tested across a wide range of point patterns (54 actual and four simulated). The maximum absolute bias was 4.4%, a significant reduction when compared with otherwise attractive alternative PDEs. Root mean squared errors and coverage of 95% confidence intervals were also encouraging. The deterrent bias issue in PDEs has been sharply reduced with the proposed estimator.
Examining the effect of diverse management strategies on landscape scale patterns of forest structure in Pennsylvania using novel remote sensing techniques
Authors: Dickinson Yvette , Zenner Eric K. , Miller Douglas
Published: January 2014

We used novel remote sensing techniques to compare the landscape-scale patterns of forest structure in Pennsylvania, USA under the management of four different agencies with varying primary objectives, including production forestry, wildlife habitat, recreation, and private ownership. We (i) developed a forest structure classification scheme using publicly available LiDAR and orthographic aerial imagery data, (ii) mapped the forest structure across twenty forested landscapes, and (iii) compared the landscape-scale forest structure patterns among the four forest management types. Our results indicate that different management philosophies and their associated forest management approaches have resulted in contrasting landscape-scale patterns of forest structure. Privately managed forests had shorter forests, higher densities of distinct patches, higher interspersion of patch types, and higher forest structure diversity at fine-scales (1.5 ha grain size) compared to forests lightly managed for recreation. Production forests under ecosystem management and forests managed for wildlife habitat exhibited intermediate patterns of forest structure. This variation in forest structure patterns among the forest managers is likely to have implications for wildlife habitat and other ecosystem services. Furthermore, greater emphasis is needed on encouraging private landowners to manage across property boundaries and providing the resources and tools to manage forests at the landscape scale.
Analysis of plastome and chondriome genome types in potato somatic hybrids from Solanum tuberosum × Solanum etuberosum
Authors: Tiwari Jagesh K. , Chandel Poonam , Singh Bir Pal , Bhardwaj Vinay
Published: January 2014

Cytoplasm types of the potato somatic hybrids from Solanum tuberosum × Solanum etuberosum were analysed using chloroplast (cp) and mitochondrial (mt) organelle genomes-specific markers. Of the 29 markers (15 cpDNA and 14 mtDNA) amplified in the 26 genotypes, 5 cpDNA (H3, NTCP4, NTCP8, NTCP9, and ALC1/ALC3) and 13 mtDNA markers showed polymorphism. The cluster analysis based on the mtDNA markers detected higher diversity compared with the cpDNA markers. Presence of new mtDNA fragments of the markers, namely, T11-2, Nsm1, pumD, Nsm3, and Nsm4, were observed, while monomorphic loci revealed highly conserved genomic regions in the somatic hybrids. The study revealed that the somatic hybrids had diverse cytoplasm types consisting predominantly of T-, W-, and C-, with a few A- and S-type cp genomes; and α-, β-, and γ-type mt genomes. Somatic hybridization has unique potential to widen the cytoplasm types of the cultivated gene pools from wild species through introgression by breeding methods.
Isolation and characterization of a wheat – Psathyrostachys huashanica ‘Keng’ 3Ns disomic addition line with resistance to stripe rust
Authors: Du Wanli , Wang Jing , Pang Yuhui , Wang Liangming , Wu Jun , Zhao Jixin , Yang Qunhui , Chen Xinhong
Published: January 2014

We isolated a wheat germplasm line, 22-2, which was derived from common wheat (Triticum aestivum ‘7182’) and Psathyrostachys huashanica ‘Keng’ (2n = 2x = 14, NsNs). Genomic composition and homoeologous relationships of 22-2 was analyzed using cytology, genomic in situ hybridization (GISH), EST–SSR, and EST–STS to characterize the alien chromatin in the transfer line. The cytological investigations showed that the chromosome number and configuration were 2n = 44 = 22 II. Mitotic and meiotic GISH using P. huashanica genomic DNA as the probe indicated that 22-2 contained a pair of P. huashanica chromosomes. The genomic affinities of the introduced P. huashanica chromosomes were determined by EST–SSR and EST–STS using multiple-loci markers from seven wheat homoeologous groups between the parents and addition line. One EST–SSR and 17 EST–STS markers, which were located on the homoeologous group 3 chromosomes of wheat, amplified polymorphic bands in 22-2 that were unique to P. huashanica. Thus, these markers suggested that the introduced Ns chromosome pair belonged to homoeologous group 3, so we designated 22-2 as a 3Ns disomic addition line. Based on disease reaction to mixed races (CYR31, CYR32, and Shuiyuan14) of stripe rust in the adult stages, 22-2 was found to have high resistance to stripe rust, which was possibly derived from its P. huashanica parent. Consequently, the new disomic addition line 22-2 could be a valuable donor source for wheat improvement depending on the excellent agronomic traits, especially, the introduction of novel disease resistance genes into wheat during breeding programs.
A Multi-Agent Care System to Support Independent Living
Authors: Kaluža Boštjan , Cvetković Božidara , Dovgan Erik , Gjoreski Hristijan , Gams Matjaž , Luštrek Mitja , Mirchevska Violeta
Published: January 2014

This paper presents a context-aware, multi-agent system called “Confidence” that helps elderly people remain independent longer by detecting falls and unusual movement, which may indicate a health problem. The system combines state-of-the-art sensor technologies and four groups of agents providing a reliable, robust, flexible monitoring system. It can call for help in case of an emergency, and issue warnings if unusual behavior is detected. The first group gathers data from the location and inertial sensors and suppresses noise. The second group reconstructs the position and activity of a person and detects the context. The third group assesses the person's condition in the environment and reacts to critical situations such as falls. The fourth group detects unusual behavior as an indicator of a potential health problem. The system was successfully tested on a scenario consisting of events that were difficult to recognize as falls, as well as in a scenario consisting of normal days and days when the person was ill. It was also demonstrated live several times, with excellent performance in complex situations.
Abductive Agents for Human Activity Monitoring
Authors: Vettier Benoit , Garbay Catherine
Published: January 2014

We propose in this paper a novel architecture for human activity monitoring, following conceptual, technical and experimental claims. From a conceptual viewpoint, we propose to approach the interpretation of sensor data as embedded into a multidimensional frame involving functional and non-functional requirements. Functional requirements involve considering the monitored person's specificities as well as the task to be performed. Non-functional requirements qualify the system activity. This frame of interpretation is continuously refined, to cope with evolving situations or expectations from the Observer. From a technical viewpoint, we propose to develop a multi-Agent architecture as a means for dependable, flexible monitoring. This paradigm allows to handle multiple, heterogeneous entities in a unified way. The Agents process incoming data with a dynamic population of hypotheses on several abstraction levels. This reasoning is abductive and fuzzy in nature. From the experimental viewpoint, we propose a dedicated evaluation approach to estimate the interpretative process unfolding. Functional and non-functional properties are presented to discuss the system's effectiveness, informativeness, sensitivity, efficiency and robustness, some of which are supported by qualitative, analytical discussions, others by quantitative measures.
A Projection Bias in Frequent Subgraph Mining Can Make a Difference
Authors: Douar Brahim , Latiri Chiraz , Liquiere Michel , Slimani Yahya
Published: January 2014

The aim of the frequent subgraph mining task is to find frequently occurring subgraphs in a large graph database. However, this task is a thriving challenge, as graph and subgraph isomorphisms play a key role throughout the computations. Since subgraph isomorphism testing is a hard problem, subgraph miners are exponential in runtime. To alleviate the complexity issue, we propose to introduce a bias in the projection operator and instead of using the costly subgraph isomorphism projection, one can use a polynomial projection having a semantically-valid structural interpretation. This paper presents a new projection operator for graphs named AC-projection, which exhibits nice theoretical complexity properties. We study the size of the search space as well as some practical properties of the projection operator. We also introduce a novel breadth-first algorithm for frequent AC-reduced subgraphs mining. Then, we prove experimentally that we can achieve an important performance gain (polynomial complexity projection) without or with non-significant loss of discovered patterns in terms of quality.
Antigen exposure leads to rigidification of germline antibody combining site
Authors: Gill Jasmita , Jayaswal Praapti , Salunke Dinakar M.
Published: January 2014

Immune complexes involving diverse antigens and corresponding antibodies were analyzed for mapping conformational transitions of an antibody before antigen binding, upon antigen binding and after antigen release. Molecular dynamics simulations of the two comprehensive datasets consisting of the antigen-free and antigen-bound structures of the germline antibodies 36-65 and BBE6.12H3 provided mechanistic model of antigen encounter by primary antibodies. While native germline antibodies exhibit substantial mobility in the antigen-combining sites, their antigen-bound states exhibit relatively rigid conformations, even in the absence of the antigen suggesting preservation of the structural state after antigen release. It is proposed that acquired rigidity by a germline antibody upon antigen binding may be the first step in affinity maturation in favor of that antigen.
KANE-PUMPLIN-REPKO FACTORIZATION: ITS APPLICATION TO PRECISION MEASUREMENTS OF TRANSVERSE SPIN ASYMMETRIES AND TO THE STUDY OF TMD EVOLUTION
Authors: SIVERS DENNIS
Published: January 2014

This article presents a summary of overlapping presentations by the author to the QCD Evolution 2013 Workshop (Jefferson Lab, May 6-10, 2013) and to the Opportunities for Polarized Physics at Fermilab workshop (Fermilab, May 20-22, 2013). It contains an introduction to the concept of Kane-Pumplin-Repko (KPR) factorization and describes how this concept can be used in the analysis of high precision measurements of parity-conserving transverse single-spin asymmetries. The discussion demonstrates that such measurements can not only probe directly for specific mechanisms that enhance our fundamental understanding of nonperturbative QCD dynamics but, because transverse spin asymmetries are unambiguously parameterized by a spin-directed momentum shift, 〈δkTN (x, μ2)〉 such measurements can also be used to calibrate other phenomenological applications of transverse momentum dependent distributions (TMDs) and of TMD evolution. The calibration supplied by these measurements can thus enable the use of TMD factorization for the exploration of a broad range of other aspects of hadronic structure. KPR factorization ensures that 〈δkTN (x, μ2)〉 remains invariant under TMD evolution and this invariance can be used in the precision comparison of transverse single-spin asymmetries in the Drell-Yan process with those in Semi-inclusive deep inelastic scattering.
EVOLUTION OF TRANSVERSE-DISTANCE DEPENDENT PARTON DENSITIES AT LARGE-XB AND GEOMETRY OF THE LOOP SPACE
Authors: CHEREDNIKOV IGOR O. , MERTENS TOM , TAELS PIETER , VAN DER VEKEN FREDERIK F.
Published: January 2014

We discuss possible applications of the equations of motion in the generalized Wilson loop space to the phenomenology of the three-dimensional parton distribution functions in the large-xB approximation. This regime is relevant for future experimental programs to be launched at the (approved) Jefferson Lab 12 GeV upgrade and the (planned) Electron-Ion Collider. We show that the geometrical evolution of the Wilson loops corresponds to the combined rapidity and renormalization-group equation of the transverse-distance dependent parton densities in the large-xB factorization scheme.
WHAT CAUSES TRANSVERSE SINGLE-SPIN ASYMMETRIES IN LEPTON-NUCLEON AND IN NUCLEON-NUCLEON SCATTERING?
Authors: METZ ANDREAS , PITONYAK DANIEL , SCHÄFER ANDREAS , SCHLEGEL MARC , VOGELSANG WERNER , ZHOU JIAN
Published: January 2014

Transverse single-spin asymmetries are among the most intriguing observables in hadronic physics. Though such asymmetries were already measured for the first time about four decades ago, their origin is still under debate. Here we consider transverse single-spin asymmetries in semi-inclusive lepton-nucleon scattering, in nucleon-nucleon scattering, and in inclusive lepton-nucleon scattering. It is argued that the single-spin asymmetries for those three processes may be simultaneously described in perturbative QCD, where the re-scattering of the active partons plays a crucial role. A comparison of single-spin asymmetries in different reactions can also shed light on the universality of transverse momentum dependent parton correlation functions. In particular, we discuss what existing data tells us about the predicted process dependence of the Sivers function.
EXPERIMENTAL DATA ON TRANSVERSE-MOMENTUM DISTRIBUTIONS FROM SEMI-INCLUSIVE DEEP-INELASTIC SCATTERING
Authors: SCHNELL GUNAR
Published: January 2014

The exploration of the structure of the nucleon reaches a new level of sophistication when explicit dependences on transverse momenta of partons in both parton distributions and fragmentation functions are included. These dependences lead to a manifold of new correlations between the nucleon and quark spin as well as their momenta and thus a wealth of experimental observables. A particular example is the novel Sivers function that—according to firm QCD predictions—has to change sign when going from the Drell-Yan process to semi-inclusive deep-inelastic scattering. Here a review is given on which knowledge has been gathered about transverse-momentum-dependent (TMD) distribution and fragmentation functions from semi-inclusive deep-inelastic scattering experiments.
NLO BFKL AND ANOMALOUS DIMENSIONS OF LIGHT-RAY OPERATORS
Authors: BALITSKY IAN
Published: January 2014

The anomalous dimensions of light-ray operators of twist two are obtained by analytical continuation of the anomalous dimensions of corresponding local operators. I demonstrate that the asymptotics of these anomalous dimensions at the "BFKL point" j → 1 can be obtained by comparing the light-cone operator expansion with the high-energy expansion in Wilson lines.
QCD REGGEON CALCULUS FROM JIMWLK EVOLUTION
Authors: ALTINOLUK TOLGA , CONTRERAS CARLOS , KOVNER ALEX , LEVIN EUGENE , LUBLINSKY MICHAEL , SHULKIM ARTHUR
Published: January 2014

We show explicitly how the high energy QCD evolution generated by the KLWMIJ Hamiltonian can be cast in the form of the QCD Reggeon Field Theory. We show how to reduce the KLWMIJ Hamitonian to physical color singlet degrees of freedom. We suggest a natural way of defining the Pomeron and other Reggeons in the framework of the KLWMIJ evolution and derive the QCD Reggeon Field Theory Hamiltonian which includes several lowest Reggeon operators. This Hamiltonian generates evolution equations for all Reggeons in the case of dilute-dense scattering, including the nonlinear Balitsky-Kovchegov equation for the Pomeron. We also find explicit expressions for the Reggeon conjugate operators in terms of QCD operators, and derive their evolution equations. This provides a natural and unambiguous framework for reggeization procedure introduced by Bartels.
NUCLEON SPIN DECOMPOSITION AT TWIST THREE
Authors: HATTA YOSHITAKA
Published: January 2014

I review the recent progress in understanding the complete gauge invariant decomposition of the nucleon spin with particular emphasis on its twist structure.
RECENT RESULTS ON HIGH-ENERGY SPIN PHENOMENA OF GLUONS AND SEA-QUARKS IN POLARIZED PROTON-PROTON COLLISIONS AT RHIC AT BNL
Authors: SURROW BERND
Published: January 2014

The STAR experiment at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory is carrying out a spin physics program in high-energy polarized proton collisions at [Formula: see text] GeV and [Formula: see text] GeV to gain a deeper insight into the spin structure and dynamics of the proton.

One of the main objectives of the spin physics program at RHIC is the precise determination of the polarized gluon distribution function. The STAR detector is well suited for the reconstruction of various final states involving jets, π0, π±, e± and γ, which allows to measure several different processes. Recent results suggest a gluon spin contribution to the proton spin at the same level as the quark spin contribution itself.

The production of W bosons in polarized p+p collisions at [Formula: see text] GeV opens a new era in the study of the spin-flavor structure of the proton. W-(+) bosons are produced in [Formula: see text] collisions and can be detected through their leptonic decays, [Formula: see text], where only the respective charged lepton is measured. Results of W-(+) production suggest a large asymmetry between the polarization of anti-u and anti-d quarks.
RECENT PROGRESS ON NUCLEON STRUCTURE WITH LATTICE QCD
Authors: LIN HUEY-WEN
Published: January 2014

I review recent progress made in the calculation of nucleon structure in lattice QCD. Due to space limitations, I will focus on a few specific topics: systematic control of lattice-QCD matrix elements, probing TeV-physics with the aid of nucleon tensor and scalar charges, and Bjorken-x dependence of nucleon parton distribution functions.
ANALYSIS OF αsFROM THE REALIZATION OF QUARK-HADRON DUALITY
Authors: COURTOY A. , LIUTI SIMONETTA
Published: January 2014

We present an analysis of the role of the running coupling constant at the intersection of perturbative and nonperturbative QCD in the context of the quark-hadron duality à la Bloom-Gilman. Our framework will be the unpolarized structure function of the proton in the resonance region. We suggest that the realization of duality is related to the inclusion of nonperturbative effects at the level of the coupling constant. The outcome of our analysis is a smooth transition from perturbative to nonperturbative QCD physics, embodied in the running of the coupling constant at intermediate scales.
MODEL INDEPENDENT CONSTRAINTS ON HADRON FORM FACTORS AT LARGE Q2 IN LIGHT-FRONT QCD
Authors: JI CHUENG-RYONG
Published: January 2014

Among the three forms of relativistic Hamiltonian dynamics proposed by Dirac in 1949, the front form has the largest number of kinematic generators. This distinction provides useful consequences in the analysis of physical observables in hadron physics. We discuss a rationale for using the front form dynamics, known nowadays as the light-front dynamics (LFD), and present a few explicit examples of hadron phenomenology that the front form uniquely can offer from the first principle QCD. In particular, model independent constraints are provided for the analyses of deuteron form factors and the NΔ transition form factors at large momentum transfer square Q2.
Retweeting the Fukushima nuclear radiation disaster
Authors: Li Jessica , Vishwanath Arun , Rao H. Raghav
Published: January 2014

The Japanese government tweeted to calm public fear, as the public generally listened to tweets expressing alarm.
A historical perspective of speech recognition
Authors: Huang Xuedong , Baker James , Reddy Raj
Published: January 2014

What do we know now that we did not know 40 years ago?
User and ISP Rights of Device Attachment and Device Management
Authors: Jordan Scott , Shaffer Gwen
Published: January 2014

Internet research often assumes users may connect devices without consent by their service providers. However, in many networks the service provider only allows use of devices obtained directly from the provider. We review how United States communications law addresses the rights of users to connect devices of their choice. We explicate a set of user and service provider rights. We propose legal requirements for attachment and management of devices. We illustrate how these proposed regulations would affect the services currently offered on telephone, cable, satellite, video networks, and cellular networks, as well as on the Internet.
A framework for applying the principles of depth perception to information visualization
Authors: Yildiz Zeynep Cipiloglu , Bulbul Abdullah , Capin Tolga
Published: January 2014

During the visualization of 3D content, using the depth cues selectively to support the design goals and enabling a user to perceive the spatial relationships between the objects are important concerns. In this novel solution, we automate this process by proposing a framework that determines important depth cues for the input scene and the rendering methods to provide these cues. While determining the importance of the cues, we consider the user's tasks and the scene's spatial layout. The importance of each depth cue is calculated using a fuzzy logic--based decision system. Then, suitable rendering methods that provide the important cues are selected by performing a cost-profit analysis on the rendering costs of the methods and their contribution to depth perception. Possible cue conflicts are considered and handled in the system. We also provide formal experimental studies designed for several visualization tasks. A statistical analysis of the experiments verifies the success of our framework.
Models of gaze control for manipulation tasks
Authors: Nunez-Varela Jose , Wyatt Jeremy L.
Published: January 2014

Human studies have shown that gaze shifts are mostly driven by the current task demands. In manipulation tasks, gaze leads action to the next manipulation target. One explanation is that fixations gather information about task relevant properties, where task relevance is signalled by reward. This work presents new computational models of gaze shifting, where the agent imagines ahead in time the informational effects of possible gaze fixations. Building on our previous work, the contributions of this article are: (i) the presentation of two new gaze control models, (ii) comparison of their performance to our previous model, (iii) results showing the fit of all these models to previously published human data, and (iv) integration of a visual search process. The first new model selects the gaze that most reduces positional uncertainty of landmarks (Unc), and the second maximises expected rewards by reducing positional uncertainty (RU). Our previous approach maximises the expected gain in cumulative reward by reducing positional uncertainty (RUG). In experiment ii the models are tested on a simulated humanoid robot performing a manipulation task, and each model's performance is characterised by varying three environmental variables. This experiment provides evidence that the RUG model has the best overall performance. In experiment iii, we compare the hand-eye coordination timings of the models in a robot simulation to those obtained from human data. This provides evidence that only the models that incorporate both uncertainty and reward (RU and RUG) match human data.
A circuit-architecture co-optimization framework for exploring nonvolatile memory hierarchies
Authors: Dong Xiangyu , Jouppi Norman P. , Xie Yuan
Published: January 2014

Many new memory technologies are available for building future energy-efficient memory hierarchies. It is necessary to have a framework that can quickly find the optimal memory technology at each hierarchy level. In this work, we first build a circuit-architecture joint design space exploration framework by combining RC circuit analysis and Artificial Neural Network (ANN)-based performance modeling. Then, we use this framework to evaluate some emerging nonvolatile memory hierarchies. We demonstrate that a Resistive RAM (ReRAM)-based cache hierarchy on an 8-core Chip-Multiprocessor (CMP) system can achieve a 24% Energy Delay Product (EDP) improvement and a 36% Energy Delay Area Product (EDAP) improvement compared to a conventional hierarchy with SRAM on-chip caches and DRAM main memory.
Modeling the impact of permanent faults in caches
Authors: Sánchez Daniel , Sazeides Yiannakis , Cebrián Juan M. , García José M. , Aragón Juan L.
Published: January 2014

The traditional performance cost benefits we have enjoyed for decades from technology scaling are challenged by several critical constraints including reliability. Increases in static and dynamic variations are leading to higher probability of parametric and wear-out failures and are elevating reliability into a prime design constraint. In particular, SRAM cells used to build caches that dominate the processor area are usually minimum sized and more prone to failure. It is therefore of paramount importance to develop effective methodologies that facilitate the exploration of reliability techniques for caches.

To this end, we present an analytical model that can determine for a given cache configuration, address trace, and random probability of permanent cell failure the exact expected miss rate and its standard deviation when blocks with faulty bits are disabled. What distinguishes our model is that it is fully analytical, it avoids the use of fault maps, and yet, it is both exact and simpler than previous approaches. The analytical model is used to produce the miss-rate trends (
expected miss-rate
) for future technology nodes for both uncorrelated and clustered faults. Some of the key findings based on the proposed model are (i) block disabling has a negligible impact on the
expected miss-rate
unless probability of failure is equal or greater than 2.6e-4, (ii) the fault map methodology can accurately calculate the
expected miss-rate
as long as 1,000 to 10,000 fault maps are used, and (iii) the
expected miss-rate
for execution of parallel applications increases with the number of threads and is more pronounced for a given probability of failure as compared to sequential execution.
The software inferno
Authors: Bell Alex E.
Published: January 2014

Dante's tale, as experienced by a software architect.
Making Consensus Tractable
Authors: Mossel Elchanan , Tamuz Omer
Published: January 2014

We study a model of consensus decision making in which a finite group of Bayesian agents has to choose between one of two courses of action. Each member of the group has a private and independent signal at his or her disposal, giving some indication as to which action is optimal. To come to a common decision, the participants perform repeated rounds of voting. In each round, each agent casts a vote in favor of one of the two courses of action, reflecting his or her current belief, and observes the votes of the rest.

We provide an efficient algorithm for the calculation the agents have to perform and show that consensus is always reached and that the probability of reaching a wrong decision decays exponentially with the number of agents.
Computationally efficient link prediction in a variety of social networks
Authors: Fire Michael , Tenenboim-Chekina Lena , Puzis Rami , Lesser Ofrit , Rokach Lior , Elovici Yuval
Published: January 2014

Online social networking sites have become increasingly popular over the last few years. As a result, new interdisciplinary research directions have emerged in which social network analysis methods are applied to networks containing hundreds of millions of users. Unfortunately, links between individuals may be missing either due to an imperfect acquirement process or because they are not yet reflected in the online network (i.e., friends in the real world did not form a virtual connection). The primary bottleneck in link prediction techniques is extracting the structural features required for classifying links. In this article, we propose a set of simple, easy-to-compute structural features that can be analyzed to identify missing links. We show that by using simple structural features, a machine learning classifier can successfully identify missing links, even when applied to a predicament of classifying links between individuals with at least one common friend. We also present a method for calculating the amount of data needed in order to build more accurate classifiers. The new
Friends measure
and
Same community
features we developed are shown to be good predictors for missing links. An evaluation experiment was performed on ten large social networks datasets: Academia.edu, DBLP, Facebook, Flickr, Flixster, Google+, Gowalla, TheMarker, Twitter, and YouTube. Our methods can provide social network site operators with the capability of helping users to find known, offline contacts and to discover new friends online. They may also be used for exposing hidden links in online social networks.
Personalized tag recommendation based on generalized rules
Authors: Cagliero Luca , Fiori Alessandro , Grimaudo Luigi
Published: January 2014

Tag recommendation is focused on recommending useful tags to a user who is annotating a Web resource. A relevant research issue is the recommendation of additional tags to partially annotated resources, which may be based on either personalized or collective knowledge. However, since the annotation process is usually not driven by any controlled vocabulary, the collections of user-specific and collective annotations are often very sparse. Indeed, the discovery of the most significant associations among tags becomes a challenging task.

This article presents a novel personalized tag recommendation system that discovers and exploits generalized association rules, that is, tag correlations holding at different abstraction levels, to identify additional pertinent tags to suggest. The use of generalized rules relevantly improves the effectiveness of traditional rule-based systems in coping with sparse tag collections, because: (i) correlations hidden at the level of individual tags may be anyhow figured out at higher abstraction levels and (ii) low-level tag associations discovered from collective data may be exploited to specialize high-level associations discovered in the user-specific context.

The effectiveness of the proposed system has been validated against other personalized approaches on real-life and benchmark collections retrieved from the popular photo-sharing system Flickr.
Active learning strategies for rating elicitation in collaborative filtering
Authors: Elahi Mehdi , Ricci Francesco , Rubens Neil
Published: January 2014

The accuracy of collaborative-filtering recommender systems largely depends on three factors: the quality of the rating prediction algorithm, and the quantity and quality of available ratings. While research in the field of recommender systems often concentrates on improving prediction algorithms, even the best algorithms will fail if they are fed poor-quality data during training, that is, garbage in, garbage out. Active learning aims to remedy this problem by focusing on obtaining better-quality data that more aptly reflects a user's preferences. However, traditional evaluation of active learning strategies has two major flaws, which have significant negative ramifications on accurately evaluating the system's performance (prediction error, precision, and quantity of elicited ratings). (1) Performance has been evaluated for each user independently (ignoring system-wide improvements). (2) Active learning strategies have been evaluated in isolation from unsolicited user ratings (natural acquisition).

In this article we show that an elicited rating has effects across the system, so a typical user-centric evaluation which ignores any changes of rating prediction of other users also ignores these cumulative effects, which may be more influential on the performance of the system as a whole (system centric). We propose a new evaluation methodology and use it to evaluate some novel and state-of-the-art rating elicitation strategies. We found that the system-wide effectiveness of a rating elicitation strategy depends on the stage of the rating elicitation process, and on the evaluation measures (MAE, NDCG, and Precision). In particular, we show that using some common user-centric strategies may actually degrade the overall performance of a system. Finally, we show that the performance of many common active learning strategies changes significantly when evaluated concurrently with the natural acquisition of ratings in recommender systems.
'Peace technologies' enable eyewitness reporting when disasters strike
Authors: Hyman Paul
Published: January 2014

Ushahidi---or "testimony" in Swahili---has played a central role in coordinating responses to crises around the globe.
How do you feel?
Authors: Geller Tom
Published: January 2014

Interfaces can sense your mood, if you let them.
MOOCs need more work; so do CS graduates
Authors: Guzdial Mark , Adams Joel C.
Published: January 2014

The
Communications
Web site, http://cacm.acm.org, features more than a dozen bloggers in the BLOG@CACM community. In each issue of
Communications
, we'll publish selected posts or excerpts.

twitter

Follow us on Twitter at http://twitter.com/blogCACM

http://cacm.acm.org/blogs/blog-cacm

Mark Guzdial assesses the first full year of massive open online courses, while Joel C. Adams considers the employment outlook for CS grads.
The Road to SDN
Authors: Feamster Nick , Rexford Jennifer , Zegura Ellen
Published: January 2014

Designing and managing networks has become more innovative over the past few years with the aid of SDN (software-defined networking). This technology seems to have appeared suddenly, but it is actually part of a long history of trying to make computer networks more programmable.
Brain Imaging Analysis
Authors: Bowman F. DuBois
Published: January 2014

The increasing availability of brain imaging technologies has led to intense neuroscientific inquiry into the human brain. Studies often investigate brain function related to emotion, cognition, language, memory, and responses to numerous other external stimuli, as well as resting-state brain function. Brain imaging studies also attempt to determine the functional or structural basis for psychiatric or neurological disorders and to examine the responses of these disorders to treatment. Neuroimaging is a highly interdisciplinary field, and statistics plays a critical role in establishing rigorous methods to extract information and to quantify evidence for formal inferences. Neuroimaging data present numerous challenges for statistical analysis, including the vast amounts of data collected from each individual and the complex temporal and spatial dependencies present in the data. I briefly provide background on various types of neuroimaging data and analysis objectives that are commonly targeted in the field. I also present a survey of existing methods aimed at these objectives and identify particular areas offering opportunities for future statistical contribution.
On the Suppression Band and Bandgap of Planar Electromagnetic Bandgap Structures
Authors: Mohajer-Iravani Baharak , Ramahi Omar M.
Published: January 2014

Electromagnetic bandgap structures are considered a viable solution for the problem of switching noise in printed circuit boards and packages. Less attention, however, has been given to whether or not the introduction of EBGs affects the EMI potential of the circuit to couple unwanted energy to neighboring layers or interconnects. In this paper, we show that the bandgap of EBG structures, as generated using the Brillouin diagram, does not necessarily correspond to the suppression bandwidth typically generated usingS-parameters. We show that the reactive near fields radiating from openings within the EBG layers can be substantial and are present in the entire frequency band including propagating and nonpropagating mode regions. These fields decay fast with distance; however, they can couple significant energy to adjacent layers and to signal lines. The findings are validated using full-wave three-dimensional numerical simulation. Based on this work, design guidelines for EBG structures can be drawn to insure not only suppression of switching noise but also minimization of EMI and insuring signal integrity.
The Effect of Inhibitory Neuron on the Evolution Model of Higher-Order Coupling Neural Oscillator Population
Authors: Qi Yi , Wang Rubin , Jiao Xianfa , Du Ying
Published: January 2014

We proposed a higher-order coupling neural network model including the inhibitory neurons and examined the dynamical evolution of average number density and phase-neural coding under the spontaneous activity and external stimulating condition. The results indicated that increase of inhibitory coupling strength will cause decrease of average number density, whereas increase of excitatory coupling strength will cause increase of stable amplitude of average number density. Whether the neural oscillator population is able to enter the new synchronous oscillation or not is determined by excitatory and inhibitory coupling strength. In the presence of external stimulation, the evolution of the average number density is dependent upon the external stimulation and the coupling term in which the dominator will determine the final evolution.
An Automatic Image Inpainting Algorithm Based on FCM
Authors: Liu Jiansheng , Liu Hui , Qiao Shangping , Yue Guangxue
Published: January 2014

There are many existing image inpainting algorithms in which the repaired area should be manually determined by users. Aiming at this drawback of the traditional image inpainting algorithms, this paper proposes an automatic image inpainting algorithm which automatically identifies the repaired area by fuzzy C-mean (FCM) algorithm. FCM algorithm classifies the image pixels into a number of categories according to the similarity principle, making the similar pixels clustering into the same category as possible. According to the provided gray value of the pixels to be inpainted, we calculate the category whose distance is the nearest to the inpainting area and this category is to be inpainting area, and then the inpainting area is restored by the TV model to realize image automatic inpainting.