bluuebunny/crossref_metadata_2025_split huggingface dataset:
The acceptability and safety of praziquantel alone and in combination with mebendazole in the treatment of Schistosoma mansoni and soil-transmitted helminthiasis in children aged 1–4 years in Uganda
Authors: NAMWANJE HARRIET , KABATEREINE NARCIS B. , OLSEN ANNETTE 
Published: February 2011

SUMMARYObjective. There is limited information on the acceptability and safety of praziquantel for treatment of schistosomiasis in children below the age of four years. In addition, although mebendazole has been extensively used together with praziquantel against infections with schistosomiasis and soil-transmitted helminthiasis (STH) in school-aged children, no specific acceptability or safety studies have been published on this drug combination in younger children. Methods. A randomized clinical trial was conducted to determine the safety of praziquantel alone and in combination with mebendazole in the treatment of Schistosoma mansoni and STH in children aged 1 to 4 years. Results. A total of 596 children from Bwondha fishing community in Mayuge district and Wang-Kado fishing community in Nebbi district were investigated using duplicate Kato-Katz thick smears of two stool samples and 130 (21·8%) were found infected with S. mansoni. Of these, 19·2% (25) had heavy intensity of infections. Of the infected children, 82 were included and randomised into praziquantel (40 mg/kg) + mebendazole (500 mg) or praziquantel (40 mg/kg) alone. Conclusion. Many symptoms were reported before treatment while very few were reported after treatment and all on treatment day. No serious adverse events were reported or observed after treatment. Praziquantel with or without mebendazole was well tolerated in small children in the study area.
Failing to adapt – the ageing immune system's role in cancer pathogenesis
Authors: Jones Christopher M 
Published: February 2011

SummaryA person's risk of developing cancer rises exponentially with age, an increase that is widely considered to result from cumulative exposure to mutagenic agents. However, cancer incidence rates decelerate and plateau beyond 85 years of age and numerous malignant pathologies peak in incidence during early or middle life, indicating an important role for additional factors in controlling the timing and nature of cancer development. Given that immune function is known to decrease with age, malignant neoplastic change may be induced by increased chronic infection and the onset of a pervasive low grade inflammatory environment. This article discusses in detail the ageing immune system's role in cancer pathogenesis and demonstrates that key polymorphisms coding for relatively low pro-inflammatory cytokine production act to protect some populations from age-induced neoplastic transformation.
Relativistic jets: Physics and simulations
Authors: Hawley John F. 
Published: February 2011

AbstractJets are one of the more dramatic and visible manifestations of black hole accretion. It is becoming increasingly accepted that magnetic fields underlie the mechanism behind the launching of relativistic jets. At the same time it is now appreciated that the fundamental driving mechanism behind accretion is due to magnetohydrodynamical processes and the stresses they engender. Global disk simulations in full general relativity have begun to reveal the radial dependence of disk stresses and the intimate connections between accretion and jet-launching. This talk will review the issues involved, the recent progress that has been made, and the challenges that remain.
Probing the accretion disk - jet connection via instabilities in the inner accretion flow. From microquasars to quasars
Authors: Janiuk Agnieszka , Czerny Bożena , Mościbrodzka Monika , Siemiginowska Aneta 
Published: February 2011

AbstractWe present various instability mechanisms in the accreting black hole systems which might indicate at the connection between the accretion disk and jet. The jets observed in microquasars can have a peristent or blobby morphology. Correlated with the accretion luminosity, this might provide a link to the cyclic outbursts of the disk. Such duty-cycle type of behaviour on short timescales results from the thermal instability caused by the radiation pressure domination. The same type of instability may explain the cyclic radioactivity of the supermassive black hole systems. The somewhat longer timescales are characteristic for the instability caused by the partial hydrogen ionization. The distortions of the jet direction and complex morphology of the sources can be caused by precession of the disk-jet axis.
Self-consistent spectra from GRMHD simulations with radiative cooling A link to reality for Sgr A*
Authors: Drappeau Samia , Dibi Salomé , Markoff Sera , Fragile Chris 
Published: February 2011

AbstractCosmos++ (Anninos et al. 2005) is one of the first fully relativistic magneto-hydro-dynamical (MHD) codes that can self-consistently account for radiative cooling, in the optically thin regime. As the code combines a total energy conservation formulation with a radiative cooling function, we have now the possibility to produce spectra energy density from these simulations and compare them to data. In this paper, we present preliminary results of spectra calculated using the same cooling functions from 2D Cosmos++ simulations of the accretion flow around Sgr A*. The simulation parameters were designed to roughly reproduce Sgr A*'s behavior at very low (10−8–10−7 M⊙/yr) accretion rate, but only via spectra can we test that this has been achieved.
Radiation from matter entrainment in astrophysical jets: the AGN case
Authors: Araudo A. T. , Bosch-Ramon V. , Romero G. E. 
Published: February 2011

AbstractJets are found in a variety of astrophysical sources. In all the cases the jet propagates with a supersonic velocity through the external medium, which can be inhomogeneous, and inhomogeneities could penetrate into the jet. The interaction of the jet material with an obstacle produces a bow-like shock within the jet in which particles can be accelerated up to relativistic energies and emit high-energy photons. In this work, we explore the active galactic nuclei scenario, focusing on the dynamical and radiative consequences of the interaction at different jet heights. We find that the produced high-energy emission could be detectable by the current γ-ray telescopes. In general, the jet-clump interactions are a possible mechanism to produce (steady or flaring) high-energy emission in many astrophysical sources in which jets are present.
Unveiling the nature of extragalactic jets with Chandra observations
Authors: Massaro F. , Cheung C. C. , Harris D. E. 
Published: February 2011

AbstractIn 1974 Fanaroff & Riley divided the extended radio sources into two classes, on the basis of their radio morphology and power. For several years we have been collecting basic parameters for extragalactic jets detected in the X-rays, looking for an extension of the classification criterion, based on their radio and X-rays properties. The fact that different processes have been proposed to explain their X-ray radiation, (synchrotron vs inverse Compton emission) suggests the possibility of a new classification scheme. However, comparing the radio-to-X-ray properties of the extragalactic jets, several aspects on their nature became unexpectedly unclear.
Radio variability of blazars
Authors: Fan J. H. , Xu W. , Pan J. , Yuan Y. H. 
Published: February 2011

AbstractIn this work, we present the analysis results using UMRAO preliminary data base. We used the light curves 1) to get the shortest timescales and then to get the brightness temperature so that we can estimate the Doppler factors; 2) to investigate the periodicity and discuss the variability index. We also used the data base to discuss the polarization properties of blazars. We found that the periodicity distribution in BL Lacs and that in the flat spectrum radio quasars should be from the same distribution. The Doppler factor in FSRQs is higher than that in BL. The polarization in BLs are higher than that in the flat spectrum radio quasars
3D-MHD simulations of the evolution of magnetic fields in FR II radio sources
Authors: Huarte-Espinosa Martín , Krause Martin , Alexander Paul 
Published: February 2011

Abstract3D-MHD numerical simulations of bipolar, hypersonic, weakly magnetized jets and synthetic synchrotron observations are presented to study the structure and evolution of magnetic fields in FR II radio sources. The magnetic field setup in the jet is initially random. The power of the jets as well as the observational viewing angle are investigated. We find that synthetic polarization maps agree with observations and show that magnetic fields inside the sources are shaped by the jets' backflow. Polarimetry statistics correlates with time, the viewing angle and the jet-to-ambient density contrast. The magnetic structure inside thin elongated sources is more uniform than for ones with fatter cocoons. Jets increase the magnetic energy in cocoons, in proportion to the jet velocity. Both, filaments in synthetic emission maps and 3D magnetic power spectra suggest that turbulence develops in evolved sources.
Relativistic jets in Narrow-Line Seyfert 1
Authors: Foschini L. , Angelakis E. , Bonnoli G. , Calderone G. , Colpi M. , D'Ammando F. , Donato D. , Falcone A. , Fuhrmann L. , Ghisellini G. , Ghirlanda G. , Hauser M. , Kovalev Y. Y. , Maraschi L. , Nieppola E. , Richards J. , Stamerra A. , Tagliaferri G. , Tavecchio F. , Thompson D. J. , Tibolla O. , Tramacere A. , Wagner S. 
Published: February 2011

AbstractNarrow-Line Seyfert 1 (NLS1) class of active galactic nuclei (AGNs) is generally radio-quiet, but a small percent of them are radio-loud. The recent discovery by Fermi/LAT of high-energy γ-ray emission from 4 NLS1s proved the existence of relativistic jets in these systems. It is therefore important to study this new class of γ-ray emitting AGNs. Here we report preliminary results about the observations of the July 2010 γ-ray outburst of PMN J0948+0022, when the source flux exceeded for the first time 10−6 ph cm−2 s−1 (E > 100 MeV).
Investigating accretion disk – radio jet coupling across the stellar mass scale
Authors: Miller-Jones James C. A. , Sivakoff Gregory R. , Altamirano Diego , Körding Elmar G. , Krimm Hans A. , Maitra Dipankar , Remillard Ron A. , Russell David M. , Tudose Valeriu , Dhawan Vivek , Fender Rob P. , Heinz Sebastian , Markoff Sera , Migliari Simone , Rupen Michael P. , Sarazin Craig L. 
Published: February 2011

AbstractRelationships between the X-ray and radio behavior of black hole X-ray binaries during outbursts have established a fundamental coupling between the accretion disks and radio jets in these systems. I begin by reviewing the prevailing paradigm for this disk-jet coupling, also highlighting what we know about similarities and differences with neutron star and white dwarf binaries. Until recently, this paradigm had not been directly tested with dedicated high-angular resolution radio imaging over entire outbursts. Moreover, such high-resolution monitoring campaigns had not previously targetted outbursts in which the compact object was either a neutron star or a white dwarf. To address this issue, we have embarked on the Jet Acceleration and Collimation Probe Of Transient X-Ray Binaries (JACPOT XRB) project, which aims to use high angular resolution observations to compare disk-jet coupling across the stellar mass scale, with the goal of probing the importance of the depth of the gravitational potential well, the stellar surface and the stellar magnetic field, on jet formation. Our team has recently concluded its first monitoring series, including (E)VLA, VLBA, X-ray, optical, and near-infrared observations of entire outbursts of the black hole candidate H 1743-322, the neutron star system Aquila X-1, and the white dwarf system SS Cyg. Here I present preliminary results from this work, largely confirming the current paradigm, but highlighting some intriguing new behavior, and suggesting a possible difference in the jet formation process between neutron star and black hole systems.
Jet-disk connection in OJ287
Authors: Valtonen Mauri J. , Savolainen Tuomas , Wiik Kaj 
Published: February 2011

AbstractA model for OJ 287 consisting of two orbiting black holes has been constructed using optical light curve data. The model has successfully predicted the occurrence of sharp optical outbursts of OJ 287 for the past 15 years. Here we test if also the variations in the radio jet position angle can be explained within the framework of this same model, which has most of its parameters fixed by the timing of the optical flares. The model applied here has only three free parameters left, the (trivial) zero point of the jet position angle, the time lag between changes in the disk and jet orientations, and the zero point of the viewing angle. Despite its simplicity and the small number of free parameters, the model appears to be able to reproduce the main properties of the observed position angle variations during the past 30 years. The best fits are obtained when the time lag is either ~4 or ~14 years. However, the jet orientation seems to be unrelated to the direction of the spin of the primary black hole. This implies, assuming that the basic model is correct, that the mean orientation of the jet is determined by the orientation of the inner accretion disk, not by the spin axis of the black hole.
Connections between jet formation and multiwavelength spectral evolution in black hole transients
Authors: Kalemci Emrah , Chun Yoon-Young , Dinçer Tolga , Buxton Michelle , Tomsick John A. , Corbel Stephane , Kaaret Philip 
Published: February 2011

AbstractMultiwavelength observations are the key to understand conditions of jet formation in Galactic black hole transient (GBHT) systems. By studying radio and optical-infrared evolution of such systems during outburst decays, the compact jet formation can be traced. Comparing this with X-ray spectral and timing evolution we can obtain physical and geometrical conditions for jet formation, and study the contribution of jets to X-ray emission.In this work, first X-ray evolution - jet relation for XTE J1752-223 will be discussed. This source had very good coverage in X-rays, optical, infrared and radio. A long exposure with INTEGRAL also allowed us to study gamma-ray behavior after the jet turns on. We will also show results from the analysis of data from GX 339-4 in the hard state with SUZAKU at low flux levels. The fits to iron line fluorescence emission show that the inner disk radius increases by a factor of >27 with respect to radii in bright states. This result, along with other disk radius measurements in the hard state will be discussed within the context of conditions for launching and sustaining jets.
A new model of emission from microquasar jets, and possible explanation to the outliers of the fundamental plane
Authors: Pe'er Asaf , Casella Piergiorgio 
Published: February 2011

AbstractWe present a new model of emission from jets in microquasars, which implements elements from the study of jets in gamma-ray bursts to these objects. By assuming that electrons are accelerated once at the base of the jet to a power law distribution above a low energy Maxwellian, and are cooled by synchrotron emission and possible adiabatic energy losses along the jet, a wealth of spectra can be obtained. We show our theoretical results which can explain some of the key observations. In particular, we show that: (I) a flat radio spectrum, as is frequently seen, is a natural outcome of the model; (II) Strong magnetic field results in a flux decay in the optical/UV band as Fν ~ ν−1/2, irrespective of many of the uncertainties of the model. (III) An increase of the magnetic field above a critical value of ~105 G leads to a sharp decrease in the flux at the radio band, while the flux at higher frequencies saturates to a constant value. We conclude that scatter in the values of the magnetic field may provide a natural explanation to the observed scatter in the radio/X ray luminosity correlation seen in these objects.
MHD simulations of jet formation - protostellar jets & applications to AGN jets
Authors: Fendt Christian , Vaidya Bhargav , Porth Oliver , Nezami Somayeh Sheikh 
Published: February 2011

AbstractJet formation MHD simulations are presented considering a variety of model setups. The first approach investigates the interrelation between the disk magnetisation profile and jet collimation. Our results suggest (and quantify) that outflows launched from a very concentrated region at the inner disk tend to be weakly collimated. In the second approach, jet formation is investigated from a magnetic field configuration consisting of a stellar dipole superposed by a strong disk field. We find that the central dipole considerably de-collimates the disk wind. In addition, reconnection flares are launched in the interaction region of disk and stellar magnetic field, subsequently changing the outflow mass flux by factors of two. The time interval between flare ejection is about 1000 Keplerian periods - surprisingly similar to the observed time lag between jet knots. The third approach considers radiative pressure effects on jet collimation - an environment which is interesting mainly for outflows from massive young stars (but also for relativistic jets). Finally we present relativistic MHD simulations of jet formation from accretion disks extenting the previous non-relativistic approaches.
Side-entrainment in a jet embedded in a sidewind
Authors: López-Cámara D. , Raga A. C. 
Published: February 2011

AbstractIn this study, we present the results from 3D simulations in which a side-streaming motion pushes the post-bow shock into direct contact with the jet beam. This is a possible mechanism for modeling well collimated molecular jets as an atomic/ionic flow which entrains molecules initially present only in the surrounding environment.
Feedback Mechanisms, Judgment Bias, and Trust Formation in Online Auctions*
Authors: Wolf James R. , Muhanna Waleed A. 
Published: February 2011

ABSTRACTOnline markets, like eBay, Amazon, and others rely on electronic reputation or feedback systems to curtail adverse selection and moral hazard risks and promote trust among participants in the marketplace. These systems are based on the idea that providing information about a trader's past behavior (performance on previous market transactions) allows market participants to form judgments regarding the trustworthiness of potential interlocutors in the marketplace. It is often assumed, however, that traders correctly process the data presented by these systems when updating their initial beliefs. In this article, we demonstrate that this assumption does not hold. Using a controlled laboratory experiment simulating an online auction site with 127 participants acting as buyers, we find that participants interpret seller feedback information in a biased (non‐Bayesian) fashion, overemphasizing the compositional strength (i.e., the proportion of positive ratings) of the reputational information and underemphasizing the weight (predictive validity) of the evidence as represented by the total number of transactions rated. Significantly, we also find that the degree to which buyers misweigh seller feedback information is moderated by the presentation format of the feedback system as well as attitudinal and psychological attributes of the buyer. Specifically, we find that buyers process feedback data presented in an Amazon‐like format—a format that more prominently emphasizes the strength dimension of feedback information—in a more biased (less‐Bayesian) manner than identical ratings data presented using an eBay‐like format. We further find that participants with greater institution‐based trust (i.e., structural assurance) and prior online shopping experience interpreted feedback data in a more biased (less‐Bayesian) manner. The implications of these findings for both research and practice are discussed.
Why Competition from a Multi‐Channel E‐Tailer Does Not Always Benefit Consumers*
Authors: Jeffers Patrick I. , Nault Barrie R. 
Published: February 2011

ABSTRACTEmpirical studies have delivered mixed conclusions on whether the widely acclaimed assertions of lower electronic retail (e‐tail) prices are true and to what extent these prices impact conventional retail prices, profits, and consumer welfare. For goods that require little in‐person pre‐ or postsales support such as CDs, DVDs, and books, we extend Balasubramanian's e‐tailer‐in‐the‐center, spatial, circular market model to examine the impact of a multichannel e‐tailer's presence on retailers' decisions to relocate, on retail prices and profits, and consumer welfare. We demonstrate several counter‐intuitive results. For example, when the disutility of buying online and shipping costs are relatively low, retailers are better off by not relocating in response to an e‐tailer's entry into the retail channel. In addition, such an entry—a multichannel strategy—may lead to increased retail prices and increased profits across the industry. Finally, consumers can be better off with less channel competition. The underlying message is that inferences regarding prices, profits, and consumer welfare critically depend on specifications of the good, disutility and shipping costs versus transportation costs (or more generally, positioning), and competition.
Building a Model of Technology Preference: The Case of Channel Choices
Authors: Muthitcharoen Achita (Mi) , Palvia Prashant C. , Grover Varun 
Published: February 2011

ABSTRACTIntention theories, such as the Theory of Reasoned Action, the Theory of Planned Behavior, and the Technology Acceptance Model (TAM), have been widely adopted to explain information system usage. These theories, however, do not explicitly consider the availability of alternative systems that users may have access to and may have a preference for. Recent calls for advancing knowledge in technology acceptance have included the examination of selection among competing channels and extending the investigation beyond adoption of a single technology. In this study, we provide a theoretical extension to the TAM by integrating preferential decision knowledge to its constructs. The concept of Attitude‐Based Preference and Attribute‐Based Preference are introduced to produce a new intention model, namely the Model of Technology Preference (MTP). MTP was validated in the context of alternative behaviors in adopting two service channels: one a technology‐based online store and the other a traditional brick‐and‐mortar store. A sample of 320 responses was used to run a structural equation model. Empirical results show that MTP is a powerful predictor of alternative behaviors. Furthermore, in the context of service channel selection, incorporating preferential decision knowledge into intention models can be used to develop successful business strategies.
Streptococcus pneumoniae Isolates from Middle Ear Fluid and Nasopharynx of Children with Acute Otitis Media Exhibit Phase Variation
Authors: Arai Jun , Hotomi Muneki , Hollingshead Susan K. , Ueno Yumi , Briles David E. , Yamanaka Noboru 
Published: February 2011

ABSTRACT
Pneumococcal phase variation of 37 middle ear and 31 nasopharyngeal isolates obtained from children with acute otitis media was examined in the absence of intervening culture. The fraction of the opaque colonies was significantly higher in middle ear isolates than in nasopharyngeal isolates. The difference is probably the result of the pneumococci adapting to differential selective environments.
Evaluation of the Gen-Probe Aptima HIV-1 RNA Qualitative Assay as an Alternative to Western Blot Analysis for Confirmation of HIV Infection
Authors: Pierce Virginia M. , Neide Brandy , Hodinka Richard L. 
Published: February 2011

ABSTRACT
The Gen-Probe Aptima HIV-1 RNA qualitative assay was evaluated as an alternative to Western blot analysis for the confirmation of HIV infection using serum samples that were repeatedly reactive for HIV antibodies. The Aptima HIV assay readily discriminated between HIV-1-infected and -uninfected individuals and effectively reduced the number of indeterminate results relative to Western blot analysis.