bluuebunny/crossref_metadata_2025 huggingface dataset:
Visualizing the Replication Cycle of Bunyamwera Orthobunyavirus Expressing Fluorescent Protein-Tagged Gc Glycoprotein
Authors: Shi Xiaohong , van Mierlo Joël T. , French Andrew , Elliott Richard M.
Published: June 2010

The virion glycoproteins Gn and Gc of Bunyamwera virus (BUNV), the prototype of the
Bunyaviridae
family and also of the
Orthobunyavirus
genus, are encoded by the medium (M) RNA genome segment and are involved in both viral attachment and entry. After their synthesis Gn and Gc form a heterodimer in the endoplasmic reticulum (ER) and transit to the Golgi compartment for virus assembly. The N-terminal half of the Gc ectodomain was previously shown to be dispensable for virus replication in cell culture (X. Shi, J. Goli, G. Clark, K. Brauburger, and R. M. Elliott, J. Gen. Virol. 90:2483-2492, 2009.). In this study, the coding sequence for a fluorescent protein, either enhanced green fluorescent protein (eGFP) or mCherry fluorescent protein, was fused to the N terminus of truncated Gc, and two recombinant BUNVs (rBUNGc-eGFP and rBUNGc-mCherry) were rescued by reverse genetics. The recombinant viruses showed bright autofluorescence under UV light and were competent for replication in various mammalian cell lines. rBUNGc-mCherry was completely stable over 10 passages, whereas internal, in-frame deletions occurred in the chimeric Gc-eGFP protein of rBUNGc-eGFP, resulting in loss of fluorescence between passages 5 and 7. Autofluorescence of the recombinant viruses allowed visualization of different stages of the infection cycle, including virus attachment to the cell surface, budding of virus particles in Golgi membranes, and virus-induced morphological changes to the Golgi compartment at later stages of infection. The fluorescent protein-tagged viruses will be valuable reagents for live-cell imaging studies to investigate virus entry, budding, and morphogenesis in real time.
Tinnitus and mobile phone use
Authors: Hutter Hans-Peter , Moshammer Hanns , Wallner Peter , Cartellieri Monika , Denk-Linnert Doris-Maria , Katzinger Michaela , Ehrenberger Klaus , Kundi Michael
Published: June 2010

Objectives

The mechanisms that produce tinnitus are not fully understood. While tinnitus can be associated with diseases and disorders of the ear, retrocochlear diseases and vascular pathologies, there are few known risk factors for tinnitus apart from these conditions. There is anecdotal evidence of an link between mobile phone use and tinnitus, but so far there have been no systematic investigations into this possible association.

Methods

100 consecutive patients presenting with tinnitus were enrolled in an individually matched case–control study. For each case a control subject was randomly selected from visiting outpatients matched for sex and age. The patient's history was obtained and clinical examinations were conducted to exclude patients with known underlying causes of tinnitus. Mobile phone use was assessed based on the Interphone Study protocol. ORs were computed by conditional logistic regression with years of education and living in an urban area as covariates.

Results

Mobile phone use up to the index date (onset of tinnitus) on the same side as the tinnitus did not have significantly elevated ORs for regular use and intensity or for cumulative hours of use. The risk estimate was significantly elevated for prolonged use (≥4 years) of a mobile phone (OR 1.95; CI 1.00 to 3.80).

Conclusions

Mobile phone use should be included in future investigations as a potential risk factor for developing tinnitus.
Work-related mortality in England and Wales, 1979–2000
Authors: Coggon David , Harris E Clare , Brown Terry , Rice Simon , Palmer Keith T
Published: June 2010

Background

To explore time trends in deaths attributable to work in England and Wales, and identify priorities for prevention, we conducted a proportional analysis of mortality by occupation over a 22-year period.

Methods

Analysis was based on deaths in men aged 20–74 years during 1979–1980 and 1982–2000 with a recorded occupation. Proportional mortality ratios, standardised for age and social class, were calculated for pre-specified combinations of occupation and cause of death, for which excess mortality could reasonably be attributed to work. Differences between observed and expected numbers of deaths by cause and occupation were expressed as annual excess death rates.

Results

Mortality attributable to work declined substantially over the period of study, with total excess death rates of 733.2 per year during 1979–1990 and 471.7 per year during 1991–2000. The largest contributing hazards were chronic obstructive pulmonary disease and pneumoconiosis in coal miners, pleural cancer from asbestos, and motor vehicle accidents in lorry drivers. In contrast to most other hazards, there was no clear decline in excess mortality attributable to asbestos, or in deaths from sino-nasal cancer associated with exposure to wood dust.

Conclusions

The overall decline in mortality attributable to work is likely to reflect reduced employment in more hazardous occupations, as well as improvements in working conditions. It is imperative to ensure that occupational exposures to asbestos and wood dust are now adequately controlled. Further research is needed on accidents involving lorries with the aim of developing more effective strategies for the prevention of injury.
SPIN PERIODICITY MEASUREMENTS OF WHITE DWARFS HOSTED IN SOUTHERN HARD X–RAY INTERMEDIATE POLAR CANDIDATES
Authors: ANDRUCHOW ILEANA , MASETTI NICOLA , DE MARTINO DOMITILLA , CELLONE SERGIO A. , MASON ELENA , BONNET-BIDAUD JEAN-MARC
Published: June 2010

Thanks to the combination of hard X–ray data afforded with the INTEGRAL satellite and optical spectroscopy at various telescopes, a number of new, possibly magnetic, Cataclysmic Variables (CVs) has been recently discovered. We here report on the preliminary analysis of B-band optical photometry performed with the 2.15m "Jorge Sahade" telescope at CASLEO (Argentina) on 5 CVs discovered at hard X–rays with INTEGRAL and which show features of a magnetic white dwarf (WD) in their optical spectra. The aim of these observations is to derive the orbital periods of these systems and the spin periodicity of their accreting WD.
HIGH-ENERGY EMISSION FROM JET–CLOUD INTERACTIONS IN AGNs
Authors: ARAUDO ANABELLA T. , BOSCH-RAMON VALENTÍ , ROMERO GUSTAVO E.
Published: June 2010

Active galactic nuclei present continuum and line emission. The emission lines are originated by gas located close to the central supermassive black hole. Some of these lines are broad, and would be produced in a small region called broad-line region. This region could be formed by clouds surrounding the central black hole. In this work, we study the interaction of such clouds with the base of the jets in active galactic nuclei, and we compute the produced high-energy emission. We focus on sources with low luminosities in the inner jet regions, to avoid strong gamma-ray absorption. We find that the resulting high-energy radiation may be significant in Centaurus A. Also, this phenomenon might be behind the variable gamma-ray emission detected in M87, if very large dark clouds are present. The detection of jet–cloud interactions in active galactic nuclei would give information on the properties of the jet base and the very central regions.
GAMMA-RAYS FROM SS 433 AND ITS INTERACTION WITH THE W50 NEBULA
Authors: BORDAS POL , BOSCH-RAMON VALENTÍ , PAREDES JOSEP MARIA
Published: June 2010

We investigate the production of gamma-rays in the inner regions of SS 433 and in its interaction between its jets and the W50 nebula. We estimate the VHE emission that can be generated within the jets at distances ≳ 1013 cm from the compact object. We also apply a theoretical model of the jet/medium interaction to SS 433/W50. We compare the predicted fluxes to observations of SS 433 at TeV energies, and derive new constraints of the physical properties of this system.
THE RELATIONSHIP AMONG XBLs, RBLs AND FSRQs
Authors: WANG HONG-GUANG , FAN JUN-HUI , HUANG YONG , PAN JING , YANG JIANG-HE
Published: June 2010

In this work, we revisited the relationship between the subclasses of blazars (X–ray selected BL Lacertae objects (XBLs), radio selected BL Lacertae objects (RBLs), and flat spectrum radio quasars (FSRQs)) based on a sample of blazars. We found that the FSRQs–RBLs–XBLs relationship is clear in their bolometric luminosity, emission line luminosity and the accretion ratio with V FSRQs > V RBLs > V XBLs , where V stands for the three parameters. However, there is no clear difference amongst their central black hole masses. The bolometric luminosity is closely correlated with the emission line luminosity and the accretion ratio.
A MODEL FOR THE INNER JET HIGH-ENERGY EMISSION OF CENTAURUS A
Authors: ORELLANA MARIANA , ROMERO GUSTAVO E.
Published: June 2010

We investigate the spectral energy distribution (SED) of Centaurus A resulting from a steady compact acceleration region, located close to the central black hole, where both leptonic and hadronic relativistic populations arise. We present here results of such a model, where we have considered synchrotron radiation by primary electrons and protons, inverse Compton scattering, and gamma-ray emission originated by the inelastic hadronic interactions between relativistic protons and cold nuclei within the jets. Photo-meson production by relativistic hadrons were also taken into account, as well as the effects of secondary particles injected by all interactions. The internal and external absorption of gamma-rays is shown to be of great relevance to shape the observable SED, which was also recently constrained by the results of Fermi and HESS.
THE COSMIC RADIO BACKGROUND AND JET CONNECTION
Authors: SINGAL JACK , STAWARZ LUKASZ , PETROSIAN VAHE , LAWRENCE ANDREW
Published: June 2010

The recently characterized Cosmic Radio Background provides a unique perspective in which to study the nonthermal universe, including properties and cosmological evolution of active galaxies and their outflows. As much as 1/3 of the total intensity of the radio background can be due to emission resulting from classical jet processes in radio galaxies and radio quiet quasars. Furthermore, weak jet activity in Seyferts and ordinary star-forming galaxies may also be important.
RADIATION FROM RELATIVISTIC SHOCKS WITH TURBULENT MAGNETIC FIELDS
Authors: NISHIKAWA K.-I. , NIMIEC J. , MEDVEDEV M. , ZHANG B. , HARDEE P. , MIZUNO Y. , NORDLUND Å. , FREDERIKSEN J. , SOL H. , POHL M. , HARTMANN D. H. , OKA M. , FISHMAN J. F.
Published: June 2010

Using our new 3D relativistic electromagnetic particle (REMP) code parallelized with MPI, we investigated long-term particle acceleration associated with a relativistic electron–positron jet propagating in an unmagnetized ambient electron–positron plasma. We have also performed simulations with electron-ion jets. The simulations were performed using a much longer simulation system than our previous simulations in order to investigate the full nonlinear stage of the Weibel instability for electron–positron jets and its particle acceleration mechanism. Cold jet electrons are thermalized and ambient electrons are accelerated in the resulting shocks for pair plasma case. Acceleration of ambient electrons leads to a maximum ambient electron density three times larger than the original value for pair plasmas. Behind the bow shock in the jet shock strong electromagnetic fields are generated. These fields may lead to time-dependent afterglow emission. We calculated radiation from electrons propagating in a uniform parallel magnetic field to verify the technique. We also used the new technique to calculate emission from electrons based on simulations with a small system with two different cases for Lorentz factors (15 and 100). We obtained spectra which are consistent with those generated from electrons propagating in turbulent magnetic fields with red noise. This turbulent magnetic field is similar to the magnetic field generated at an early nonlinear stage of the Weibel instability.
HIGH-ENERGY PHENOMENA STUDIED WITH X–RAY POLARIMETRY
Authors: MATT GIORGIO
Published: June 2010

After more than 30 years since the last X–ray polarimetric measurements, performed in the 70's by the OSO-8 satellite, thanks to recent technological advances, polarimetry is considered again as a viable technique for studing X–ray sources. In this contribution the author briefly discusses a couple of astrophysical situations, related to the topics of this conference, where X–ray polarimetry can be extremely useful. The author also discusses the observational perspectives, listing the main future space missions (proposed or even already approved) carrying on-board an X–ray polarimeter.
VERITAS: STATUS SUMMARY 2009
Authors:   VERITAS Collaboration (see for list of institutions), WEEKES T. C. , ACCIARI V. A. , ARLEN T. , AUNE T. , BEILICKE M. , BENBOW W. , BOLTUCH D. , BRADBURY S. M. , BUCKLEY J. H. , BUGAEV V. , BYRUM K. , CANNON A. , CESARINI A. , CIUPIK L. , CHOW Y. C. , COGAN P. , CUI W. , DUKE C. , FEGAN S. J. , FINLEY J. P. , FINNEGAN G. , FORTIN P. , FORTSON L. , FURNISS A. , GALANTE N. , GALL D. , GILLANDERS G. H. , GODAMBE S. , GRUBE J. , GUENETTE R. , GYUK G. , HANNA D. , HOLDER J. , HORAN D. , HUI C. M. , HUMENSKY T. B. , IMRAN A. , KAARET P. , KARLSSON N. , KERTZMAN M. , KIEDA D. , KONOPELKO A. , KRAWCZYNSKI H. , KRENNRICH F. , LANG M. J. , MAIER G. , MCARTHUR S. , MCCANN A. , MCCUTCHEON M. , MILLIS J. , MORIARTY P. , ONG R. A. , OTTE A. N. , PANDEL D. , PERKINS J. S. , PICHEL A. , POHL M. , QUINN J. , RAGAN K. , REYES L. C. , REYNOLDS P. T. , ROACHE E. , ROSE H. J. , ROVERO A. , SCHROEDTER M. , SEMBROSKI G. H. , SMITH A. W. , STEELE D. , SWORDY S. P. , THEILING M. , THIBADEAU S. , TONER J. A. , VARLOTTA A. , VASSILIEV V. V. , VINCENT S. , WAGNER R. G. , WAKELY S. P. , WARD J. E. , WEINSTEIN A. , WILLIAMS D. A. , WISSEL S. , WOOD M. , ZITZER B.
Published: June 2010

VERITAS is a ground-based gamma-ray observatory that uses the imaging atmospheric Cherenkov technique and operates in the very-high energy (VHE) region of the gamma-ray spectrum from 100 GeV to 50 TeV. The observatory consists of an array of four 12 m-diameter imaging atmospheric Cherenkov telescopes located in southern Arizona, USA. The four-telescope array has been fully operational since September 2007, and over the last two years, VERITAS has been operating with high reliability and sensitivity. It is currently one of the most sensitive VHE observatories. This paper summarizes the status of VERITAS as of October 2009, and describes the detection of several new VHE gamma-ray sources.
RESULTS FROM H.E.S.S. OBSERVATIONS OF RELATIVISTIC SOURCES
Authors:   For the H.E.S.S. Collaboration, DE ALMEIDA ULISSES BARRES
Published: June 2010

The High Energy Stereoscopic System (H.E.S.S.) is a southern hemisphere array of four Imaging Atmospheric Cherenkov Telescopes observing the sky in the very-high energy gamma-ray range (E > 100 GeV ). VHE observations are an invaluable tool to study the acceleration and propagation of energetic particles in many astrophysical systems where relativistic outflows are the main drivers of the emission, such as AGNs and galactic binary systems. In this paper the main results of the H.E.S.S. observations of these objects will be reviewed, and the general picture that emerges from them will be presented. We will also comment on prospects for future investigations with H.E.S.S.-II.
RESULTS FROM GALACTIC OBSERVATIONS WITH MAGIC
Authors:   On behalf of the MAGIC Collaboration, RICO JAVIER
Published: June 2010

MAGIC is a single-dish Cherenkov telescope located on La Palma (Spain), hence with an optimal view on the Northern sky. Sensitive to the 30 GeV–30 TeV energy band, it is nowadays the only ground-based instrument being able to measure high-energy gamma-rays below 100 GeV. With the operation in coincidence with MACIC-II, starting in Fall 2009, the sensitivity will be improved by a factor ~ 2. We review the results obtained by MAGIC on the very-high energy emission from pulsars, binary systems and microquasars.
SEARCH FOR NEARBY EXTRAGALACTIC SOURCES OF THE HIGHEST ENERGY COSMIC RAYS
Authors:   For the Pierre Auger Collaboration, HARARI DIEGO
Published: June 2010

The Pierre Auger Observatory has measured that the flux of cosmic rays is strongly suppressed above 4 × 1019 eV . This is consistent with the prediction that cosmic rays with larger energies can only arrive from nearby sources since they must surmount the losses caused by propagation through the cosmic microwave background. The observatory has also found evidence that the inhomogeneous distribution of nearby extragalactic matter imprints its anisotropy upon the arrival directions of cosmic rays with energy above ~ 6 × 1019 eV . Correlations are observed with the positions of active galactic nuclei within 100 Mpc, and with other distributions of local extragalactic objects. An excess of events is observed from a region of the sky close to the location of the radio source Cen A. Current measurements identify neither individual sources nor a specific class of sites of origin. We review these results and discuss the perspectives that similar studies with future data, complemented with further measurements of composition of the cosmic rays, may identify their astrophysical sources.
ICECUBE NEUTRINO OBSERVATORY
Authors:   For the IceCube Collaboration, ABBASI RASHA
Published: June 2010

This contribution is a brief report on the IceCube kilometer cubed neutrino telescope located at the geographical South Pole. IceCube construction is on schedule to be completed in 2011. The full detector will consist of 86 strings, each with 60 digital optical modules. At the time of writing 59 strings of IceCube are taking data. Based on the data taken to date, the telescope meets its design goals. Selected results of ongoing analysis of IceCube detector data are presented.
SIMULATIONS OF DYNAMICS AND EMISSION FROM MAGNETIZED GRB AFTERGLOWS
Authors: MIMICA PETAR , GIANNIOS DIMITRIOS , ALOY MIGUEL ANGEL
Published: June 2010

The role of magnetic fields in the GRB flow is still controversial. The afterglow emission, particularly the early phases, may provide a probe into the magnetization of the outflow. Using ultrahigh resolution relativistic MHD simulations, the interaction between radially expanding magnetized ejecta with the interstellar medium is studied. We explore the effect of the magnetic field strength of the ejecta on the afterglow structure, particularly regarding the presence and strength of a reverse shock. We compute synthetic afterglow light curves to quantify the effect of the magnetization of the flow on observed radiation.
THE X–RAY CORONA AND JET OF CYGNUS X-1
Authors: MALZAC JULIEN , BELMONT RENAUD
Published: June 2010

Evidence is presented indicating that in the hard state of Cygnus X-1, the coronal magnetic field might be below equipartition with radiation (suggesting that the corona is not powered by magnetic field dissipation) and that the ion temperature in the corona is significantly lower than what predicted by ADAF like models. It is also shown that the current estimates of the jet power set interesting contraints on the jet velocity (which is at least mildly relativistic), the accretion efficiency (which is large in both spectral states), and the nature of the X–ray emitting region (which is unlikely to be the jet).
IS THE CORONA THE SOURCE OF THE EJECTED MATERIAL IN MICROQUASARS?
Authors: RODRIGUEZ JEROME , PRAT LIONEL
Published: June 2010

Microquasar outbursts are characterized by spectral state transitions. The transitions between states characterized by a hard spectrum and those characterized by a soft spectrum are of particular interest. Besides drastic spectral and timing changes, these transitions often show discrete ejections detectable in the radio domain. The mechanisms giving birth to the ejections, the links with accretion and the exact nature of the ejected material are still largely unknown. We present systematic X–ray spectral analysis prior to the ejection in several microquasars, and show that, in each case, the properties of the corona drastically evolve, while that of the disc remain roughly constant. We intepret this behavior as possibly due to an ejection of the corona at the spectral transition.
TWO-COMPONENT JETS AND THE FANAROFF–RILEY DICHOTOMY
Authors: MELIANI ZAKARIA , KEPPENS RONY , SAUTY CHRISTOPHE
Published: June 2010

Transversely stratified jets are observed in many classes of astrophysical objects, ranging from young stellar objects, μ-quasars, to active galactic nuclei and even in gamma-ray bursts. Theoretical arguments support this transverse stratification of jets with two components induced by intrinsic features of the central engine (accretion disk + black hole). In fact, according to the observations and theoretical models, a typical jet has an inner fast low density jet, surrounded by a slower, denser, extended jet. We elaborate on this model and investigate for the first time this two-component jet evolution with very high resolution in 3D. We demonstrate that two-component jets with a high kinetic energy flux contribution from the inner jet are subject to the development of a relativistically enhanced, rotation-induced Rayleigh–Taylor type non-axisymmetric instability. This instability induces–strong mixing between both components, decelerating the inner jet and leading to overall jet decollimation. This novel scenario of sudden jet deceleration and decollimation can explain the radio source Fanaroff–Riley dichotomy as a consequence of the efficiency of the central engine in launching the inner jet component versus the outer jet component. We infer that the FRII/FRI transition, interpreted in our two-component jet scenario, occurs when the relative kinetic energy flux of the inner to the outer jet exceeds a critical ratio.
ON MAGNETIC SELF-COLLIMATION OF RELATIVISTIC JETS
Authors: GLOBUS N. , CAYATTE V. , SAUTY C.
Published: June 2010

We present a semi-analytical model using the equations of general relativistic magnetohydrodynamics (GRMHD) for jets emitted by a rotating black hole. We assume steady axisymmetric outflows of a relativistic ideal fluid in Kerr metrics. We express the conservation equations in the frame of the FIDucial Observer (FIDO or ZAMO) using a 3+1 space–time splitting. Calculating the total energy variation between a non-polar field line and the polar axis, we extend to the Kerr metric the simple criterion for the magnetic collimation of jets obtained for a nonrotating black hole by Meliani et al.10 We show that the black role rotation induced a more efficient magnetic collimation of the jet.
GAMMA-RAY EMISSION FROM AGNS (SPECIAL FOCUS ON BL LAC OBJECTS)
Authors: TAVECCHIO F.
Published: June 2010

Blazars, radio-loud active galactic nuclei with the relativistic jet closely aligned with the line of sight, dominate the extragalactic sky observed at gamma-ray energies, above 100 MeV. We discuss some of the emission properties of these sources, focusing in particular on the "blazar sequence" and the interpretative models of the high-energy emission of BL Lac objects.
M 87 — TEN YEARS OF TEV GAMMA-RAY OBSERVATIONS
Authors: BEILICKE MATTHIAS
Published: June 2010

The giant radio galaxy M 87 is located 16.7 Mpc away and harbours a supermassive black hole in its center. Structures of its relativistic plasma jet are resolved at radio, optical and X–ray energies. M 87 belongs to the class of active galactic nuclei and is one of only a few radio galaxies detected at very-high energies (E > 100 GeV ). This makes it a unique laboratory to study jet physics and the corresponding emission processes. The results obtained from TeV gamma-ray observations during the last decade are discussed.
PERIODICITY ANALYSIS OF THE SPECTRAL INDEX IN 3C 273 AND 3C 446
Authors: YUAN YU-HAI , FAN JUN-HUI
Published: June 2010

In this work, we used the preliminary data of University of Michigan Radio Astronomy Observatory (UMRAO) for the spectral index calculation for two blazars, 3C 273 (1226+023) and 3C 446 (2223-052), and found that the spectral indices are variable. Therefore, we used three methods (Jurkevich method (J), the discrete correlation analysis (D), and the Periodogram method (P)) to investigate the period in the spectral index variation curves. The results show that 3C 273 has a quasi-period of 8.8 ± 1.3 yr , and 3C 446 has a period of 5.8 ± 1.2 yr .
Lipopolysaccharides directly decrease Ca2+ oscillations and the hyperpolarization-activated nonselective cation current If in immortalized HL-1 cardiomyocytes
Authors: Wondergem Robert , Graves Bridget M. , Ozment-Skelton Tammy R. , Li Chuanfu , Williams David L.
Published: June 2010

Lipopolysaccharide (LPS) has been implicated in sepsis-mediated heart failure and chronic cardiac myopathies. We determined that LPS directly and reversibly affects cardiac myocyte function by altering regulation of intracellular Ca2+ concentration ([Ca2+]i) in immortalized cardiomyocytes, HL-1 cells. [Ca2+]i oscillated (<0.4 Hz), displaying slow and transient components. LPS (1 μg/ml), derived either from Escherichia coli or from Salmonella enteritidis , reversibly abolished Ca2+ oscillations and decreased basal [Ca2+]i by 30–40 nM. HL-1 cells expressed Toll-like receptors, i.e., TLR-2 and TLR-4. Thus, we differentiated effects of LPS on [Ca2+]i and Ca2+ oscillations by addition of utlrapure LPS, a TLR-4 ligand. Ultrapure LPS had no effect on basal [Ca2+]i, but it reduced the rate of Ca2+ oscillations. Interestingly, Pam3CSK4, a TLR-2 ligand, affected neither Ca2+ parameter, and the effect of ultrapure LPS and Pam3CSK4 combined was similar to that of utlrapure LPS alone. Thus, unpurified LPS directly inhibits HL-1 calcium metabolism via TLR-4 and non-TLR-4-dependent mechanisms. Since others have shown that endotoxin impairs the hyperpolarization-activated, nonselective cationic pacemaker current ( If), which is expressed in HL-1 cells, we utilized whole cell voltage-clamp techniques to demonstrate that LPS (1 μg/ml) reduced If in HL-1 cells. This inhibition was marginal at physiologic membrane potentials and significant at very negative potentials ( P < 0.05 at −140, −150, and −160 mV). So, we also evaluated effects of LPS on tail currents of fully activated If. LPS reduced the slope conductance of the tail currents from 498 ± 140 pS/pF to 223 ± 65 pS/pF ( P < 0.05) without affecting reversal potential of −11 mV. Ultrapure LPS had similar effect on If, whereas Pam3CSK4 had no effect on If. We conclude that LPS inhibits activation of If, enhances its deactivation, and impairs regulation of [Ca2+]i in HL-1 cardiomyocytes via TLR-4 and other mechanisms.
Nerve-released acetylcholine contracts urinary bladder smooth muscle by inducing action potentials independently of IP3-mediated calcium release
Authors: Nausch Bernhard , Heppner Thomas J. , Nelson Mark T.
Published: June 2010

Nerve-released ACh is the main stimulus for contraction of urinary bladder smooth muscle (UBSM). Here, the mechanisms by which ACh contracts UBSM are explored by determining Ca2+ and electrical signals induced by nerve-released ACh. Photolysis of caged inositol 1,4,5-trisphosphate (IP3) evoked Ca2+ release from the sarcoplasmic reticulum. Electrical field stimulation (20 Hz) induced Ca2+ waves within the smooth muscle that were present only during stimulus application. Ca2+ waves were blocked by inhibition of muscarinic ACh receptors (mAChRs) with atropine and depletion of sarcoplasmic reticulum Ca2+ stores with cyclopiazonic acid (CPA), and therefore likely reflect activation of IP3 receptors (IP3Rs). Electrical field stimulation also increased excitability to induce action potentials (APs) that were accompanied by Ca2+ flashes, reflecting Ca2+ entry through voltage-dependent Ca2+ channels (VDCCs) during the action potential. The evoked Ca2+ flashes and APs occurred as a burst with a lag time of ∼1.5 s after onset of stimulation. They were not inhibited by blocking IP3-mediated Ca2+ waves, but by blockers of mAChRs (atropine) and VDCCs (diltiazem). Nerve-evoked contractions of UBSM strips were greatly reduced by blocking VDCCs, but not by preventing IP3-mediated Ca2+ signaling with cyclopiazonic acid or inhibition of PLC with U73122. These results indicate that ACh released from nerve varicosities induces IP3-mediated Ca2+ waves during stimulation; but contrary to expectations, these signals do not appear to participate in contraction. In addition, our data provide compelling evidence that UBSM contractions evoked by nerve-released ACh depend on increased excitability and the resultant Ca2+ entry through VDCCs during APs.
Race, sex, and the regulation of urine osmolality: observations made during water deprivation
Authors: Hancock Michael L. , Bichet Daniel G. , Eckert George J. , Bankir Lise , Wagner Mary Anne , Pratt J. Howard
Published: June 2010

A more concentrated urine is excreted by blacks than whites and by men than women. The purpose of this study was to explore the physiological bases for the race and sex effects during water deprivation when osmoregulation is challenged and differences are amplified. Drinking water was withheld from 17 blacks (10 men) and 19 whites (9 men) for 24 h. Vasopressin (VP) levels and osmolality in plasma (Posmol) and urine (Uosmol) were measured basally and then every 4 h. Uosmol was higher in blacks at baseline ( P = 0.01) and during water deprivation ( P = 0.046). Before and during water deprivation, no differences were seen in levels of VP, Posmol, or the VP-Uosmol relationship between blacks and whites. Although VP levels were initially higher in men ( P < 0.02 for samples collected over the first 12 h), over the last 12 h of water deprivation, Uosmol was higher ( P = 0.027) and more responsive to the level of VP (in terms of slopes, P = 0.0001) in women than men. Our results suggest that, after a period of water deprivation, there develops a sensitivity of the collecting duct to VP that is greater in women. Although Uosmol is higher in blacks, the race difference in water conservation did not appear to result from differences in the level of VP or the sensitivity of the collecting duct to VP. Upstream effects such as Na+ uptake in the thick ascending limb, with its ensuing effects on water reabsorption, need to be considered in future studies of the relationship of race to water conservation.
Sex differences in acute ANG II-mediated hemodynamic responses in mice
Authors: Schneider Markus P. , Wach Paul F. , Durley Melissa K. , Pollock Jennifer S. , Pollock David M.
Published: June 2010

Male sex is associated with higher blood pressure and greater renal injury, perhaps related to greater sensitivity to ANG II. In anesthetized male and female C57BLK/6 mice, we assessed responses of mean arterial pressure (MAP) and renal vascular resistance (RVR; Transonic flow probe) to acute bolus injections of ANG II (0.3–3.0 μg/kg iv) and phenylephrine (PE; 30–300 μg/kg) during low-, normal-, and high-sodium diets. The role of reactive oxygen species was determined by coadministration of tempol. ANG II type 1 and type 2 (AT1 and AT2) receptor and endothelial nitric oxide synthase (NOS3) expression were determined in dissected kidney vessels. While no difference was found on the low-sodium (LS) diet, MAP and RVR responses to ANG II were greater in males during the normal-sodium (NS) and high-sodium (HS) diets (e.g., RVR response at ANG II 3.0 μg/kg during NS: +329 ± 22 vs. +271 ± 28 mmHg·ml−1·min, P = 0.029, effect size = 0.75). Tempol had no effect on the sex-dependent responses on any of the diets. On the LS diet, AT1 and AT2 receptor expression was higher in males. No sex differences were found on the NS diet. On the HS diet, AT1 was higher, and NOS3 expression was lower in males. Acute responses to ANG II are greater in male mice during NS and HS diets, which is, in part, related to differences in AT1, AT2, and NOS3 expression in kidney vessels. Mouse models will be useful to study the role of sex differences in ANG II sensitivity for cardiovascular and renal disease.
Skeletal muscle structural and energetic characteristics in subjects with sickle cell trait, α-thalassemia, or dual hemoglobinopathy
Authors: Vincent Lucile , Féasson Léonard , Oyono-Enguéllé Samuel , Banimbek Viviane , Monchanin Géraldine , Dohbobga Macias , Wouassi Dieudonné , Martin Cyril , Gozal David , Geyssant André , Thiriet Patrice , Denis Christian , Messonnier Laurent
Published: June 2010

Previous studies have shown that subjects with sickle cell trait (SCT), α-thalassemia (α-t), and the dual hemoglobinopathy (SCT/α-t) manifest subtle, albeit significant, differences during exercise. To better understand such differences, we assessed skeletal muscle histomorphological and energetic characteristics in 10 control HbAA subjects (C), 5 subjects with α-t (α-t), 6 SCT carriers (SCT) and 9 SCT carriers with α-t (SCT/α-t). Subjects underwent a muscle biopsy and also performed an incremental maximal exercise and a time to exhaustion test. There were no observable differences in daily energy expenditure, maximal power output (Pmax), or time to exhaustion at 110% Pmax ( Tex) among the groups. Blood lactate concentrations measured at the end of the Tex, muscle fiber type distribution, and mean phosphofructokinase (PFK), lactate dehydrogenase (LDH), β-hydroxyacyl-CoA-dehydrogenase (HAD), and citrate synthase (CS) activities were all similar among the four groups. However, SCT was associated with a lower cytochrome- c oxidase (COx) activity in type IIa fibers ( P < 0.05), and similar trends were observed in fiber types I and IIx. Trends toward lower creatine kinase (CK) activity ( P = 0.0702) and higher surface area of type IIx fibers were observed in SCT ( P = 0.0925). In summary, these findings support most of the previous observations in SCT, such as 1) similar maximal power output and associated maximal oxygen consumption (V̇o2max) values and 2) lower exercise performances during prolonged submaximal exercise. Furthermore, performances during short supramaximal exercise were not different in SCT. Finally, the dual hemoglobinopathy condition does not seem to affect muscle characteristics.
Reliability of Long-Interval Cortical Inhibition in Healthy Human Subjects: A TMS–EEG Study
Authors: Farzan Faranak , Barr Mera S. , Levinson Andrea J. , Chen Robert , Wong Willy , Fitzgerald Paul B. , Daskalakis Zafiris J.
Published: June 2010

Cortical inhibition (CI) is measured by transcranial magnetic stimulation (TMS) combined with electromyography (EMG) through long-interval CI (LICI) and cortical silent period (CSP) paradigms. Recently, we illustrated that LICI can be measured from the dorsolateral prefrontal cortex (DLPFC) through combined TMS with electroencephalography (EEG). We further demonstrated that LICI had different effects on cortical oscillations in the DLPFC compared with motor cortex. The purpose of this study was to establish the validity and reliability of TMS–EEG indices of CI and to replicate our previous findings in an extended sample. The validity of TMS–EEG was examined by evaluating its relationship to standard EMG measures of LICI and the CSP in the left motor cortex in 36 and 16 subjects, respectively. Test–retest reliability was examined in 14 subjects who returned for a repeat session within 7 days of the first session. LICI was applied to the left DLPFC in 30 subjects to compare LICI in the DLPFC with that in the motor cortex. In the motor cortex, EEG measures of LICI correlated with EMG measures of LICI and CSP. All indices of LICI showed high test–retest reliability in motor cortex and DLPFC. Gamma and beta oscillations were significantly inhibited in the DLPFC but not in the motor cortex, confirming previous findings in an extended sample. These findings demonstrate that indexing LICI through TMS combined with EEG is a valid and reliable method to evaluate inhibition from motor and prefrontal regions.
Equivalence of the Apollonian and Its Inner Metric
Authors: Hästö Peter , Ponnusamy S. , Sahoo S. K.
Published: June 2010

We show that the equivalence of the Apollonian metric
and its inner metric remains unchanged by the removal of a point from the
domain. For this we need to assume that the complement of the domain is not
contained in a hyperplane. This improves a result of the authors wherein the
same conclusion was reached under the stronger assumption that the domain
contains an exterior point.
Porosity and Mechanical Strength of an Autoclaved Clayey Cellular Concrete
Authors: Guglielmi P. O. , Silva W. R. L. , Repette W. L. , Hotza D.
Published: June 2010

This paper investigates the porosity and the mechanical strength of an Autoclaved Clayey Cellular Concrete (ACCC) with the binder produced with 75 wt% kaolinite clay and 25 wt% Portland cement. Aluminum powder was used as foaming agent, from 0.2 wt% to 0.8 wt%, producing specimens with different porosities. The results show that the specimens with higher content of aluminum presented pore coalescence, which can explain the lower porosity of these samples. The porosities obtained with the aluminum contents used in the study were high (approximately 80%), what accounts for the low mechanical strength of the investigated cellular concretes (maximum of 0.62 MPa). Nevertheless, comparing the results obtained in this study to the ones for low temperature clayey aerated concrete with similar compositions, it can be observed that autoclaving is effective for increasing the material mechanical strength.
Hybrid Viscosity Iterative Method for Fixed Point, Variational Inequality and Equilibrium Problems
Authors: Chen Yi-An , Zhang Yi-Ping
Published: June 2010

We introduce an iterative scheme by the viscosity iterative method for finding a common element of the solution set of an equilibrium problem, the solution set of the variational inequality, and the fixed points set of infinitely many nonexpansive mappings in a Hilbert space. Then we prove our main result under some suitable conditions.
The Expression and Functions of Toll-Like Receptors in Atherosclerosis
Authors: Cole Jennifer E. , Georgiou Ektoras , Monaco Claudia
Published: June 2010

Inflammation drives atherosclerosis. Both immune and resident vascular cell types are involved in the development of atherosclerotic lesions. The phenotype and function of these cells are key in determining the development of lesions. Toll-like receptors are the most characterised innate immune receptors and are responsible for the recognition of exogenous conserved motifs on pathogens, and, potentially, some endogenous molecules. Both endogenous and exogenous TLR agonists may be present in atherosclerotic plaques. Engagement of toll-like receptors on immune and resident vascular cells can affect atherogenesis as signalling downstream of these receptors can elicit proinflammatory cytokine release, lipid uptake, and foam cell formation and activate cells of the adaptive immune system. In this paper, we will describe the expression of TLRs on immune and resident vascular cells, highlight the TLR ligands that may act through TLRs on these cells, and discuss the consequences of TLR activation in atherosclerosis.
The Relationship between Tests of Neurocognition and Performance on a Laparoscopic Simulator
Authors: Kuzbari Oumar , Crystal Howard , Bral Pedram , Atiah Rima A. A. , Kuzbari Imad , Khachani Amine , Aslam Muhammad Faisal , Minkoff Howard
Published: June 2010

Objective. To estimate if there is a relationship between the results of tests of neurocognition and performance on a laparoscopic surgery simulator.Methods and Materials. Twenty participants with no prior laparoscopic experience had baseline cognitive tests administered (Trail Making Test, Part A and B (TMT-A and TMT-B), Grooved Peg Board Test, Symbol Digit Modalities Test, Symbol Digit Recall Test, and Stroop Interference Test), completed a demographic questionnaire, and then performed laparoscopy using a simulator. We correlated the results of cognitive tests with laparoscopic surgical performance.Results. One cognitive test sensitive to frontal lobe function, TMT-A, significantly correlated with laparoscopic surgical performance on the simulator (correlation coefficient of 0.534 withP<.05). However, the correlation between performance and other cognitive tests (TMT-B, Grooved Peg Board Test, Symbol Digit Modalities Test, Symbol Digit Recall Test, and Stroop Interference Test) was not statistically significant.Conclusion. Laparoscopic performance may be related to measures of frontal lobe function. Neurocognitive tests may predict motor skills abilities and performance on laparoscopic simulator.
Cytokine-Induced Monocyte Characteristics in SLE
Authors: Zhang Zhe , Maurer Kelly , Perin Juan C. , Song Li , Sullivan Kathleen E.
Published: June 2010

Monocytes in SLE have been described as having aberrant behavior in a number of assays. We examined gene expression and used a genome-wide approach to study the posttranslational histone mark, H4 acetylation, to examine epigenetic changes in SLE monocytes. We compared SLE monocyte gene expression and H4 acetylation with three types of cytokine-treated monocytes to understand which cytokine effects predominated in SLE monocytes. We found thatγ-interferon andα-interferon both replicated a broad range of the gene expression changes seen in SLE monocytes. H4 acetylation in SLE monocytes was overall higher than in controls and there was less correlation of H4ac with cytokine-treated cells than when gene expression was compared. A set of chemokine genes had downregulated expression and H4ac. Therefore, there are significant clusters of aberrantly expressed genes in SLE which are strongly associated with altered H4ac, suggesting that these cells have experienced durable changes to their epigenome.
Unsupervised Segmentation Methods of TV Contents
Authors: El-Khoury Elie , Sénac Christine , Joly Philippe
Published: June 2010

We present a generic algorithm to address various temporal segmentation topics of audiovisual contents such as speaker diarization, shot, or program segmentation. Based on a GLR approach, involving the ΔBIC criterion, this algorithm requires the value of only a few parameters to produce segmentation results at a desired scale and on most typical low-level features used in the field of content-based indexing. Results obtained on various corpora are of the same quality level than the ones obtained by other dedicated and state-of-the-art methods.
Bacteriophage Administration Reduces the Concentration ofListeria monocytogenesin the Gastrointestinal Tract and Its Translocation to Spleen and Liver in Experimentally Infected Mice
Authors: Mai Volker , Ukhanova Maria , Visone Lee , Abuladze Tamar , Sulakvelidze Alexander
Published: June 2010

To investigate the efficacy of phage supplementation in reducing pathogen numbers, mice were treated via oral gavage with aListeria monocytogenesphage preparation (designated ListShield) before being orally infected withL. monocytogenes. The concentrations ofL. monocytogenesin the liver, spleen, and intestines were significantly lower (P<.05) in the phage-treated than in the control mice. Phage and antibiotic treatments were similarly effective in reducing the levels ofL. monocytogenesin the internal organs of the infected mice. However, the significant weight loss detected in the control and antibiotic-treated groups was not observed in the infected, ListShield-treated mice. Long-term (90 days), biweekly treatment of uninfected mice with ListShield did not elicit detectable changes in the microbiota of their large intestines or deleterious changes in their health. Our data support the potential feasibility of using bacteriophages to control proliferation ofL. monocytogenesin mice without affecting commensal microbiota composition.
Dynamic MRR Function Optimization Using Calculus of Variations
Authors: Lan Tian-Syung
Published: June 2010

A dynamic machining model to optimize the control of material removal rate (MRR) for a cutting tool undergoing the considerations of fixed tool life and maximum machining rate is established in this paper. This study not only applies material removal rate mathematically into the objective function, but also implements Calculus of Variations to comprehensively optimize the control of material removal rate. In addition, the optimal solution for the dynamic machining model to gain the maximum profit is provided, and the decision criteria for selecting the optimal solution of the dynamic machining model are then recommended. Moreover, the computerized analyses to simulate both the dynamic and traditional machining models for a numerical example are also promoted. This study definitely contributes an applicable approach to the dynamic function of material removal rate and provides the efficient tool to concretely optimize the profit of a cutting tool for operation planning and control in modern machining industry with profound insight.
Modulation of Muscle Atrophy, Fatigue and MLC Phosphorylation by MuRF1 as Indicated by Hindlimb Suspension Studies on MuRF1-KO Mice
Authors: Labeit Siegfried , Kohl Christine H. , Witt Christian C. , Labeit Dittmar , Jung Jeong , Granzier Henk
Published: June 2010

MuRF1 is a member of the TRIM/RBCC superfamily, a gene family that encompasses a large variety of proteins, all sharing the conserved TRIM (TripartiteMotive) sequential array ofRING,B-box, and coiled-coil domains. Within this family, MuRF1(also named TRIM63) is a specialized member that contributes to the development of muscle atrophy and sarcopenia. Here we studied MuRF1's role in muscle atrophy during muscle unloading induced by hindlimb suspension. Consistent with previous studies, we found that MuRF1 inactivation leads to an attenuated muscle atrophy response. The amount of protection was higher as compared to the denervation model, and within the 10 day-suspension period the soleus muscle was spared from atrophy in MuRF1-KO mice. Contractility studies on hindlimb suspended muscle tissues suggested that MuRF1's functions extend beyond muscle trophicity and implicate MuRF1 in muscle fatigue and MLC phosphorylation control: soleus muscle from MuRF1-KO mice fatigued significantly faster and in addition showed a reduced posttetanic twitch potentiation. Thus the present work further established the role of MuRF1 in muscle atrophy and for the first time shows that MuRF1 plays a role in muscle fatigue and twitch potentiation.
Nonviral Gene Delivery to Mesenchymal Stem Cells Using Cationic Liposomes for Gene and Cell Therapy
Authors: Madeira C. , Mendes R. D. , Ribeiro S. C. , Boura J. S. , Aires-Barros M. R. , da Silva C. L. , Cabral J. M. S.
Published: June 2010

Mesenchymal stem cells (MSCs) hold a great promise for application in several therapies due to their unique biological characteristics. In order to harness their full potential in cell-or gene-based therapies it might be advantageous to enhance some of their features through gene delivery strategies. Accordingly, we are interested in developing an efficient and safe methodology to genetically engineer human bone marrow MSC (BM MSC), enhancing their therapeutic efficacy in Regenerative Medicine. The plasmid DNA delivery was optimized using a cationic liposome-based reagent. Transfection efficiencies ranged from ~2% to ~35%, resulting from using a Lipid/DNA ratio of 1.25 with a transgene expression of 7 days. Importantly, the number of plasmid copies in different cell passages was quantified for the first time and ~20,000 plasmid copies/cell were obtained independently of cell passage. As transfected MSC have shown high viabilities (>90%) and recoveries (>52%) while maintaining their multipotency, this might be an advantageous transfection strategy when the goal is to express a therapeutic gene in a safe and transient way.