bluuebunny/crossref_metadata_2025 huggingface dataset:
DISCRETE SECOND-ORDER EULER–POINCARÉ EQUATIONS: APPLICATIONS TO OPTIMAL CONTROL
Authors: COLOMBO LEONARDO , JIMÉNEZ FERNANDO , DE DIEGO DAVID MARTÍN
Published: April 2012

In this paper we will discuss some new developments in the design of numerical methods for optimal control problems of Lagrangian systems on Lie groups. We will construct these geometric integrators using discrete variational calculus on Lie groups, deriving a discrete version of the second-order Euler–Lagrange equations. Interesting applications as, for instance, a discrete derivation of the Euler–Poincaré equations for second-order Lagrangians and its application to optimal control of a rigid body, and of a Cosserat rod are shown at the end of the paper.
WHITE UPCONVERSION LUMINESCENCE FROM (Yb3+/Tm3+/Ho3+) TRIDOPED GdF3 NANORODS AFTER HEAT TREATMENT
Authors: GUO LINNA , WANG YUHUA , ZHANG JIA , WANG YANZHAO , DONG PENGYU
Published: April 2012

A series of Ho3+/Yb3+/Tm3+ tridoped GdF 3 nanorods with different dopant concentrations were synthesized by a hydrothermal method. Transmission electron microscope (TEM) images indicate that the length and diameter of the nanorods is about 90 nm and 31 nm, respectively on average. No bright white upconversion light was observed from the samples with different Yb 3+, Ho 3+ or Tm 3+ concentrations. Unexpectedly, the emission color coordinates of the samples after heat treatment move toward the central white region of the chromaticity diagram, and among these samples, the color coordinate (0.349, 0.329) of GdF 3:15% Yb 3+, 0.1% Ho 3+, 0.8% Tm 3+ is the most close to the standard white light (0.333, 0.333). This is unlike previous reports in which white light was achieved via tuning dopant concentration or excitation power. The reasons for the above phenomenon are presented by means of FT-IR spectra and the energy level diagram of dopants.
LOCATING THE BLAZAR EMISSION SITE WITH FERMI VARIABILITY
Authors: GEORGANOPOULOS MARKOS , DOTSON AMANDA , KAZANAS DEMOSTHENES , PERLMAN ERIC
Published: April 2012

This work presents a method for settling the following ongoing debate: is the GeV emission of powerful blazars produced inside the sub-pc size broad line region (BLR) or further out at scales of ~ 10 pc where the IR photon field of the dusty molecular torus dominates over that the UV field of the BLR? In the first case the GeV emission is most probably external Compton (EC) scattering of the ~ 10 eV BLR photons21, while in the second the seed photons for the EC GeV emission are the ~ 0.1 eV photons of the dust9 in the molecular torus8. The issue of the energy dissipation location is connected to the jet formation and collimation process25 and, as we argue here, can be resolved with Fermi spectral variability observations.
LINEARLY POLARIZED SUPERLUMINAL WAVES IN PULSAR WINDS
Authors: ARKA IOANNA , KIRK JOHN G.
Published: April 2012

Pulsar winds are the ideal environment for the study of non-linear electromagnetic waves. It is generally thought that a pulsar launches a striped wind, a magnetohydrodynamic entropy wave, where plasma sheets carried along with the flow separate regions of alternating magnetic field. But when the density drops below a critical value, or equivalently for distances from the pulsar greater than a critical radius, a strong superluminal wave can also propagate. In this contribution we discuss the conversion of the equatorial striped wind into a linearly polarized superluminal wave, and we argue that this mode is important for the conversion of Poynting flux to kinetic energy flux before the outflow reaches the termination shock.
CONSTRAINTS ON X-RAY POLARIZATION OF SYNCHROTRON JETS FROM STELLAR-MASS BLACK HOLES
Authors: RUSSELL D. M.
Published: April 2012

For most black hole X-ray binaries, the fraction of X-ray flux originating in the synchrotron jets is generally thought to be low in the hard state. However in one intriguing case, the infrared – X-ray correlations, evolution of broadband spectra and timing signatures suggest that synchrotron emission from a jet likely dominated both the infrared and X-ray flux on the hard state decline of an outburst of XTE J1550–564 at a luminosity of ~ (2 × 10-4 – 2 × 10-3) L Edd . Synchrotron emission from the relativistic jets launched close to black holes can be highly linearly polarized, depending on the configuration of the magnetic field. It has recently been shown that the polarimetric signature of their jets is detected in the infrared and is highly variable. This reveals the magnetic geometry in a region of the compact jet near its base, close to the black hole. From these results, it is predicted that in some cases, high (possibly up to 10%), variable levels of X-ray polarization from synchrotron emission originating in jets will be detected from accreting black holes by future spaceborne X-ray polarimeters.
CONSTRAINING THE PULSAR POWER IN GAMMA-RAY BINARIES THROUGH THERMAL X-RAY EMISSION
Authors: ZABALZA VÍCTOR , BOSCH-RAMON VALENTÍ , PAREDES JOSEP MARIA
Published: April 2012

Gamma-ray binaries are binary systems that show non-thermal broadband emission from radio to gamma rays. If the system comprises a massive star and a young non-accreting pulsar, their winds collide producing non-thermal emission, most likely from the shocked pulsar wind. Thermal X-rays are expected from the shocked stellar wind, with a spectrum akin to the one observed in massive star binaries. The goal of this work is, through the study of the thermal X-ray emission from the shocked stellar wind in pulsar gamma-ray binaries, constrain the pulsar spin-down luminosity and the stellar wind properties. A semi-analytic model is developed to compute the thermal X-ray emission from the shocked stellar wind in pulsar gamma-ray binaries. The model results are compared with XMM-Newton observations of LS 5039, a candidate pulsar gamma-ray binary with a strong stellar wind. Exploring the range of possible values for the stellar mass-loss rate and orbital inclination, we obtain an upper limit on the pulsar spin-down luminosity of 6 × 1036 erg s-1. We conclude that, to explain the non-thermal luminosity of LS 5039 in the pulsar wind scenario, a non-thermal to spin-down luminosity ratio very close to unity may be required.
PARTICLE ACCELERATION AT THE TERMINATION SHOCK OF STRIPED PULSAR WINDS
Authors: SIRONI LORENZO , SPITKOVSKY ANATOLY
Published: April 2012

The relativistic wind of pulsars consists of toroidal stripes of opposite magnetic field polarity, separated by current sheets of hot plasma. By means of multi-dimensional particle-in-cell simulations, we investigate particle acceleration and magnetic field dissipation at the termination shock of a relativistic striped pulsar wind. At the shock, the flow compresses and the alternating fields annihilate by driven magnetic reconnection. Irrespective of the stripe wavelength λ or the wind magnetization σ (in the regime σ ≫1 of magnetically dominated flows), shock-driven reconnection transfers all the magnetic energy of alternating fields to the particles. In the limit λ/(rL σ) ≫ 1, where rL is the relativistic Larmor radius in the wind, the post-shock spectrum approaches a flat power-law tail with slope around -1.5, populated by particles accelerated by the reconnection electric field. Our findings place important constraints on the models of non-thermal radiation from Pulsar Wind Nebulae.
CLOSE BINARY PROGENITORS OF HYPERNOVAE
Authors: BARKOV MAXIM V.
Published: April 2012

In this paper we propose a new plausible mechanism of supernova explosions specific to close binary systems. The starting point is the common envelope phase in the evolution of a binary consisting of a red super giant and a neutron star. As the neutron star spirals towards the center of its companion it spins up via disk accretion. Depending on the specific angular momentum of gas captured by the neutron star via the Bondi-Hoyle mechanism, it may reach millisecond periods either when it is still inside the common envelope or after it has merged with the companion core. The high accretion rate may result in strong differential rotation of the neutron star and generation of a magnetar-strength magnetic field. The magnetar wind can blow away the common envelope if its magnetic field is as strong as 1015 G, and can destroy the entire companion if it is as strong as 1016 G. The total explosion energy can be comparable to the rotational energy of a millisecond pulsar and reach 1052 erg. The result is an unusual type-II supernova with very high luminosity during the plateau phase, followed by a sharp drop in brightness and a steep light-curve tail. The remnant is either a solitary magnetar or a close binary involving a Wolf-Rayet star and a magnetar. When this Wolf-Rayet star explodes this will be a third supernovae explosion in the same binary. A particularly interesting version of the binary progenitor involves merger of a red super giant star with an ultra-compact companion, neutron star or black hole. In the case if a strong magnetic field is not generated on the surface of a neutron star then it will collapse to a black hole. After that we expect the formation of a very long-lived accretion disk around the black hole. The Blandford-Znajek driven jet from this black hole may drive not only hypernovae explosion but produce a bright X-ray transient event on a time scale of 104 s.
THE UNUSUAL EMISSION STRUCTURE 140 PC FROM THE CORE IN THE JET OF THE RADIO GALAXY 3C 120
Authors: CASADIO CAROLINA , GÓMEZ JOSÉ L. , ROCA-SOGORB MAR , AGUDO IVÁN
Published: April 2012

We present Very Long Baseline Array observations of the radio galaxy 3C 120 during 2010, revealing the existence of a very unusual component (hereafter C80) located at 80 mas (deprojected to 140 pc) with a brightness temperature ≈ 600 times higher than expected at such distance from the core. No significant changes in the position and flux density of C80 has been observed from its discovered up to these new observations suggesting that it may be associated with a strong recollimation shock. Components downstream of C80 move at superluminal velocities, resembling the situation near the HST-1 component in M87.
SUPERGIANT FAST X-RAY TRANSIENTS: SWIFT RESULTS AND THEORETICAL PROGRESS
Authors:   on behalf of the SFXT project. http://www.ifc.inaf.it/sfxt/, FARINELLI RUBEN , ROMANO PATRIZIA , VERCELLONE STEFANO , CECCOBELLO C. , TITARCHUK L.
Published: April 2012

We present an overview of our Supergiant Fast X-ray Transients (SFXT) project, by highlighting the unique observational contribution Swift is giving to this exciting new field. Since 2007 Swift has been detecting outbursts from these fast transients with the BAT and following them intensively for days with the XRT so that we now have a firm estimate of the time SFXTs spend in each intensity phase. We summarize some preliminary results on our XSPEC model that numerically solves the bulk-motion radiative transfer equation with a strong magnetic field, in the Fokker-Planck approximation.
SIMULATION OF SHOCK-SHOCK INTERACTION IN PARSEC-SCALE JETS
Authors: FROMM CHRISTIAN M. , PERUCHO MANEL , ROS EDUARDO , MIMICA PETAR , SAVOLAINEN TUOMAS , LOBANOV ANDREI P. , ZENSUS J. ANTON
Published: April 2012

The analysis of the radio light curves of the blazar CTA 102 during its 2006 flare revealed a possible interaction between a standing shock wave and a traveling one. In order to better understand this highly non-linear process, we used a relativistic hydrodynamic code to simulate the high energy interaction and its related emission. The calculated synchrotron emission from these simulations showed an increase in turnover flux density, Sm, and turnover frequency, νm, during the interaction and decrease to its initial values after the passage of the traveling shock wave.
IMPLICATIONS OF PC AND KPC JET ASYMMETRY TO THE COSMIC RAY ACCELERATION
Authors: GIZANI NECTARIA A. B.
Published: April 2012

We probe the role that the directional asymmetry, between relativistic outflows and kilo-parsec scale jets, play in the acceleration of cosmic rays. For this reason we use two powerful, nearby Active Galactic Nuclei (AGNs). These radio galaxies are atypical compared to the usual AGN as they contain ring-like features instead of hotspots. Our VLBI radio data have revealed a substantial misalignment between their small and large scale jets. Taking into account the overall information we have obtained about the AGNs themselves (VLA and VLBI radio data at 18 cm) and their clusters (X-ray observations) our study supports the present ideas of powerful radiogalaxies (radio quiet and radio loud) being sources of cosmic rays as well as their ability to accelarate the latter to ultra high energies.
EXTENDED REGIONS OF RADIO EMISSION NOT ASSOCIATED WITH THE AGN PHENOMENON AS SOURCES OF ACCELERATION OF COSMIC RAYS: THE CASE OF cD GALAXIES
Authors: GIZANI NECTARIA A. B.
Published: April 2012

Diffuse, non-thermal extended emission not associated with the AGN phenomenon, found in many clusters of galaxies hosted by an AGN, are related to the acceleration of cosmic rays. In the current work we present preliminary evidence of absence of such formations in clusters of galaxies hosted by optically identified cD galaxies. Our subsample consists of three powerful low redshift radiogalaxies, centered in poor clusters of galaxies. We have searched for radio relics and (mini) halos which could be forming as a result of the confinement of cosmic rays by bubbles creayed by the AGN. We report on the work in progress.
ACCRETION AND OUTFLOW FROM A MAGNETIZED, NEUTRINO COOLED TORUS AROUND THE GAMMA RAY BURST CENTRAL ENGINE
Authors: JANIUK AGNIESZKA , MOSCIBRODZKA MONIKA
Published: April 2012

Gamma Ray Bursts (GRB) are the extremely energetic transient events, visible from the most distant parts of the Universe. They are most likely powered by accretion on the hyper-Eddington rates that proceeds onto a newly born stellar mass black hole. This central engine gives rise to the most powerful, high Lorentz factor jets that are responsible for energetic gamma ray emission. We investigate the accretion flow evolution in GRB central engine, using the 2D MHD simulations in General Relativity. We compute the structure and evolution of the extremely hot and dense torus accreting onto the fast spinning black hole, which launches the magnetized jets. We calculate the chemical structure of the disk and account for neutrino cooling. Our preliminary runs apply to the short GRB case (remnant torus accreted after NS-NS or NS-BH merger). We estimate the neutrino luminosity of such an event for chosen disk and central BH mass.
MAGNETIC FIELD AMPLIFICATION BY RELATIVISTIC SHOCKS IN AN INHOMOGENEOUS MEDIUM
Authors: MIZUNO YOSUKE , POHL MARTIN , NIEMIEC JACEK , ZHANG BING , NISHIKAWA KEN-ICHI , HARDEE PHILIP E.
Published: April 2012

We perform two-dimensional relativistic magnetohydrodynamic simulations of a mildly relativistic shock propagating through an inhomogeneous medium. We show that the postshock region becomes turbulent owing to preshock density inhomogeneity, and the magnetic field is strongly amplified due to the stretching and folding of field lines in the turbulent velocity field. The amplified magnetic field evolves into a filamentary structure in two-dimensional simulations. The magnetic energy spectrum is flatter than the Kolmogorov spectrum and indicates that the so-called small-scale dynamo is occurring in the postshock region. We also find that the amplitude of magnetic-field amplification depends on the direction of the mean preshock magnetic field.
FIELD AMPLIFICATION, VORTEX FORMATION, AND ELECTRON ACCELERATION IN A PLASMA PROTOSHOCK: EFFECT OF ASYMMETRIC DENSITY PROFILE
Authors: MURPHY GARETH C. , DIECKMANN MARK E. , O'C DRURY LUKE
Published: April 2012

Gamma ray bursts (GRBs) are thought to originate from highly relativistic jets. The fireball model predicts internal shocks in the jets, causing magnetic field to be amplified & particles to be accelerated. We model the effects of an asymmetric density configuration for an internal plasma collision in a quasi-parallel magnetic field. We measured electron acceleration & found that a tenuous population of electrons is accelerated to Lorentz factors of ~ 300 - close to energy equipartition with ions. We found that the filaments did not remain static, but were deflected by the Lorentz force & rolled up into small vortices, which themselves merge to form a larger current vortex.
THE HIGH-ENERGY PROPERTIES OF 3C 454.3: A FOUR-YEAR STUDY
Authors:   on behalf of the AGILE Team, VERCELLONE STEFANO
Published: April 2012

The blazar 3C 454.3 has become the most active and brightest γ-ray source of the sky, earning the nickname of Crazy Diamond. The short-term variability in the γ-ray energy band and the extremely high peak fluxes reached during intense flaring episodes make 3C 454.3 one of the best targets to investigate the blazar jet properties. We will review four years of observational properties of this remarkable source, discussing both short- and long-term multi-wavelength campaigns, with particular emphasis on the recent flaring episode which occurred on 2010 November 20, when 3C 454.3 reached on a daily time-scale a gamma-ray flux (E > 100 MeV) higher than 6 × 10-5 photons cm-2 s-1, about six times the flux of the brightest γ-ray steady source, the Vela Pulsar.
ClC-3 is a candidate of the channel proteins mediating acid-activated chloride currents in nasopharyngeal carcinoma cells
Authors: Wang Liwei , Ma Wenbo , Zhu Linyan , Ye Dong , Li Yuan , Liu Shanwen , Li Huarong , Zuo Wanhong , Li Bingxue , Ye Wencai , Chen Lixin
Published: April 2012

Acid-activated chloride currents have been reported in several cell types and may play important roles in regulation of cell function. However, the molecular identities of the channels that mediate the currents are not defined. In this study, activation of the acid-induced chloride current and the possible candidates of the acid-activated chloride channel were investigated in human nasopharyngeal carcinoma cells (CNE-2Z). A chloride current was activated when extracellular pH was reduced to 6.6 from 7.4. However, a further decrease of extracellular pH to 5.8 inhibited the current. The current was weakly outward-rectified and was suppressed by hypertonicity-induced cell shrinkage and by the chloride channel blockers 5-nitro-2–3-phenylpropylamino benzoic acid (NPPB), tamoxifen, and 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid disodium salt hydrate (DIDS). The permeability sequence of the channel to anions was I− > Br− > Cl− > gluconate−. Among the ClC chloride channels, ClC-3 and ClC-7 were strongly expressed in CNE-2Z cells. Knockdown of ClC-3 expression with ClC-3 small interfering (si)RNA prevented the activation of the acid-induced current, but silence of ClC-7 expression with ClC-7 siRNA did not significantly affect the current. The results suggest that the chloride channel mediating the acid-induced chloride current was volume sensitive. ClC-3 is a candidate of the channel proteins that mediate or regulate the acid-activated chloride current in nasopharyngeal carcinoma cells.
Diode probes for spatiotemporal optical control of multiple neurons in freely moving animals
Authors: Stark Eran , Koos Tibor , Buzsáki György
Published: April 2012

Neuronal control with high temporal precision is possible with optogenetics, yet currently available methods do not enable to control independently multiple locations in the brains of freely moving animals. Here, we describe a diode-probe system that allows real-time and location-specific control of neuronal activity at multiple sites. Manipulation of neuronal activity in arbitrary spatiotemporal patterns is achieved by means of an optoelectronic array, manufactured by attaching multiple diode-fiber assemblies to high-density silicon probes or wire tetrodes and implanted into the brains of animals that are expressing light-responsive opsins. Each diode can be controlled separately, allowing localized light stimulation of neuronal activators and silencers in any temporal configuration and concurrent recording of the stimulated neurons. Because the only connections to the animals are via a highly flexible wire cable, unimpeded behavior is allowed for circuit monitoring and multisite perturbations in the intact brain. The capacity of the system to generate unique neural activity patterns facilitates multisite manipulation of neural circuits in a closed-loop manner and opens the door to addressing novel questions.
Learning complex temporal patterns with resource-dependent spike timing-dependent plasticity
Authors: Hunzinger Jason F. , Chan Victor H. , Froemke Robert C.
Published: April 2012

Studies of spike timing-dependent plasticity (STDP) have revealed that long-term changes in the strength of a synapse may be modulated substantially by temporal relationships between multiple presynaptic and postsynaptic spikes. Whereas long-term potentiation (LTP) and long-term depression (LTD) of synaptic strength have been modeled as distinct or separate functional mechanisms, here, we propose a new shared resource model. A functional consequence of our model is fast, stable, and diverse unsupervised learning of temporal multispike patterns with a biologically consistent spiking neural network. Due to interdependencies between LTP and LTD, dendritic delays, and proactive homeostatic aspects of the model, neurons are equipped to learn to decode temporally coded information within spike bursts. Moreover, neurons learn spike timing with few exposures in substantial noise and jitter. Surprisingly, despite having only one parameter, the model also accurately predicts in vitro observations of STDP in more complex multispike trains, as well as rate-dependent effects. We discuss candidate commonalities in natural long-term plasticity mechanisms.
Rapid changes in extracellular glutamate induced by natural arousing stimuli and intravenous cocaine in the nucleus accumbens shell and core
Authors: Wakabayashi Ken T. , Kiyatkin Eugene A.
Published: April 2012

Glutamate (Glu) is a major excitatory neurotransmitter, playing a crucial role in the functioning of the nucleus accumbens (NAc), a critical area implicated in somatosensory integration and regulation of motivated behavior. In this study, high-speed amperometry with enzyme-based biosensors was used in freely moving rats to examine changes in extracellular Glu in the NAc shell and core induced by a tone, tail pinch (TP), social interaction with a male conspecific (SI), and intravenous (iv) cocaine (1 mg/kg). To establish the contribution of Glu to electrochemical signal changes, similar recordings were conducted with null (Glu0) sensors, which were exposed to the same chemical and physical environment but were insensitive to Glu. TP, SI, and cocaine, but not a tone, induced relatively large and prolonged current increases detected by both Glu and Glu0 sensors. However, current differentials revealed very rapid, much smaller, and transient increases in extracellular Glu levels, more predominantly in the NAc shell than core. In contrast to monophasic responses with natural stimuli, cocaine induced a biphasic Glu increase in the shell, with a transient peak during the injection and a slower postinjection peak. Therefore, Glu is phasically released in the NAc after exposure to natural arousing stimuli and cocaine; this release is rapid, stimulus dependent, and structure specific, suggesting its role in triggering neural and behavioral activation induced by these stimuli. This study also demonstrates the need for multiple in vitro and in vivo controls to reveal relatively small, highly phasic, and transient fluctuations in Glu levels occurring under behaviorally relevant conditions.
Midbrain contributions to sensorimotor decision making
Authors: Felsen Gidon , Mainen Zachary F.
Published: April 2012

Making decisions about future actions is a fundamental function of the nervous system. Classical theories hold that separate sets of brain regions are responsible for selecting and implementing an action. Traditionally, action selection has been considered the domain of high-level regions, such as the prefrontal cortex, whereas action generation is thought to be carried out by dedicated cortical and subcortical motor regions. However, increasing evidence suggests that the activity of individual neurons in cortical motor structures reflects abstract properties of “decision variables” rather than conveying simple motor commands. Less is known, though, about the role of subcortical structures in decision making. In particular, the superior colliculus (SC) is critical for planning and initiating visually guided, gaze-displacing movements and selecting visual targets, but whether and how it contributes more generally to sensorimotor decisions are unclear. Here, we show that the SC is intimately involved in orienting decisions based on odor cues, even though the SC does not explicitly process olfactory stimuli. Neurons were recorded from the intermediate and deep SC layers in rats trained to perform a delayed-response, odor-cued spatial choice task. SC neurons commonly fired well in advance of movement initiation, predicting the chosen direction nearly 1 s before movement. Moreover, under conditions of sensory uncertainty, SC activity varied with task difficulty and reward outcome, reflecting the influence of decision variables on the intercollicular competition thought to underlie orienting movements. These results indicate that the SC plays a more general role in decisions than previously appreciated, extending beyond visuomotor functions.
3D QSAR of Pyrrolo Pyrimidine and Thieno Pyrimidines as Human Thymidylate Synthase Inhibitors
Authors: Kumari K. Meena , Yamini L. , Vijjulatha M.
Published: April 2012

Thymidylate synthase (TS) is a crucial enzyme for DNA biosynthesis and many nonclassical lipophilic antifolates targeting this enzyme are quite efficient and encouraging as antitumor drugs. We report 3D‐QSAR analyses on pyrrolo pyrimidine and thieno pyrimidine antifolates to contemplate the mechanism of action and structure‐activity relationship of these molecules. By applying leave‐one‐out (LOO) cross‐validation study, cross‐validated q2 value of 0.523 and 0.566 for CoMFA Ligand based (LB) and Receptor based (RB), 0.516 and 0.471 for CoMSIA LB and RB respectively. while the non‐cross‐validated r2 values were found to be 0.974 and 0.969 for CoMFA LB and RB, 0.983 and 0.972 for CoMSIA LB and RB respectively. The models were graphically interpreted using CoMFA and CoMSIA contour plots. The results obtained from this study were used for rational design of potent inhibitors against thymidylate synthase.
Influence of Perceived Racial Discrimination on Health and Behaviour of Immigrant Children in British Columbia
Authors: George M. Anne , Bassani Cherylynn , Armstrong Robert W.
Published: April 2012

This study examines the influence of perceived discrimination on the health and behaviour of ethnic minority immigrant children in British Columbia, Canada. Using data from the New Canadian Children and Youth Study, we examine perceived discrimination experienced by the parent, family, and cultural group in Canada to test the influence of micro-, meso-, and macrolevels of discrimination on children. Families from 6 ethnic backgrounds participated in the study. Parents’ perceptions of the child’s health and six behavioral scales (hyperactivity, prosocial behaviour, emotional problems, aggression, indirect aggression, and a general combined behaviour scale) were examined as outcome variables. After controlling for ethnicity and background variables, our findings suggest that perceived micro- and macrodiscrimination has the greatest influence on the health and behaviour of our immigrant child sample. Variation among ethnic groups provided the largest explanation of health and behavioural discrepancies in our study.
Risk Factors for Gestational Diabetes Mellitus in a Large Population of Women Living in Spain: Implications for Preventative Strategies
Authors: Ramos-Leví Ana M. , Pérez-Ferre Natalia , Fernández M. Dolores , del Valle Laura , Bordiu Elena , Bedia Ana Rosa , Herraiz Miguel A. , Torrejón M. José , Calle-Pascual Alfonso L.
Published: April 2012

The aim of this study is to establish a risk appraisal model for GDM by identifying modifiable factors that can help predict the risk of GDM in a large population of 2194 women living in Spain. They were recruited between 2009-2010 when screening for GDM was performed. Participants completed a questionnaire on socio-demographic, anthropomorphic and behavioral characteristics, and reproductive and medical history. A total of 213 (9.7%) women were diagnosed as having GDM. Age, pregestational body weight (BW) and body mass index (BMI), and number of events of medical, obstetric and family history were significantly associated with GDM. After logistic regression model, biscuits and pastries intake <4 times/week, red and processed meats intake <6 servings/week, sugared drinks <4 servings/week, light walking >30 minutes/day, and 30 minutes/day of sports at least 2 days/week, compared with opposite consumption, was associated with less GDM risk. Our study identified several pregestational modifiable lifestyle risk factors associated with an increase in the risk of developing GDM. This may represent a promising approach for the prevention of GDM and subsequent complications. Further intervention studies are needed to evaluate if this appraisal model of risk calculation can be useful for prevention and treatment of GDM.
3D‐QSAR Study of Indol‐2‐yl Ethanones Derivatives as Novel Indoleamine 2,3‐Dioxygenase (IDO) Inhibitors
Authors: Bhadoriya Kamlendra S. , Jain Shailesh V. , Bari Sanjaykumar B. , Chavhan Manish L. , Vispute Kuldeep R.
Published: April 2012

3D‐QSAR approach using kNN‐MFA was applied to a series of Indol‐2‐yl ethanones derivatives as novel IDO inhibitors. For the purpose, 22 compounds were used to develop models. To elucidate the structural properties required for IDO inhibitory activity, we report here k‐nearest neighbor molecular field analysis (kNN‐MFA)‐based 3D‐QSAR model for Indol‐2‐yl ethanones derivatives as novel IDO inhibitors. Overall model classification accuracy was 76.27% (q2 = 0.7627, representing internal validation) in training set and 79.35% (pred_r2 = 0.7935, representing external validation) in test set using sphere exclusion and forward as a method of data selection and variable selection, respectively. Contour maps using this approach showed that hydrophobic and steric effects dominantly determine binding affinities. The information rendered by 3D‐QSAR model may lead to a better understanding of structural requirements of IDO inhibitors and can help in the design of novel potent molecules.
The Long-Term Outcomes after Radical Prostatectomy of Patients with Pathologic Gleason 8–10 Disease
Authors: Lewinshtein Dan , Teng Brandon , Valencia Ashley , Gibbons Robert , Porter Christopher R.
Published: April 2012

Background. We explored the long-term clinical outcomes including metastases-free survival and prostate cancer-specific survival (PCSS) in patients with pathologic Gleason 8–10 disease after radical prostatectomy (RP).Methods. We report on 91 patients with PCSS data with a median followup of 8.2 years after RP performed between 1988 and 1997. Cox regression and Kaplan-Meier analysis were used to evaluate year of surgery, pathologic stage, and surgical margin status as predictors of PCSM.Results. Median age was 65 years (IQR: 61–9), and median PSA was 9.7 ng/ml (IQR: 6.1–13.4). Of all patients, 62 (68.9%) had stage T3 disease or higher, and 48 (52.7%) had a positive surgical margin. On multivariate analysis, none of the predictors were statistically significant. Of all patients, the predicted 10-year BCR-free survival, mets-free survival, and PCSS were 59% (CI: 53%–65%), 88% (CI: 84%–92%), and 94% (CI: 91%–97%), respectively.Conclusions. We have demonstrated that cancer control is durable even 10 years after RP in those with pathologic Gleason 8–10 disease. Although 40% will succumb to BCR, only 6% of patients died of their disease. These results support the use of RP for patients with high-risk localized prostate cancer.
Characterization of Fly Ash Generated from Matla Power Station in Mpumalanga, South Africa
Authors: Ayanda Olushola S. , Fatoki Olalekan S. , Adekola Folahan A. , Ximba Bhekumusa J.
Published: April 2012

In this study, fly ash was obtained from Matla power station and the physicochemical properties investigated. The fly ash was characterized by x‐ray fluorescence, x‐ray diffraction, scanning electron microscopy, and inductively coupled plasma mass spectrometry. Surface area, particle size, ash and carbon contents, pH, and point of zero charge were also measured. The results showed that the fly ash is alkaline and consists mainly of mullite (Al6Si2O13) and quartz (SiO2). Highly toxic metals As, Sb, Cd, Cr, and Pb as well as metals that are essential to health in trace amounts were also present. The storage and disposal of coal fly ash can thus lead to the release of leached metals into soils, surface and ground waters, find way into the ecological systems and then cause harmful effect to man and its environments.
Laser Performance of 1% at. Yb : Lu2O3 Ceramic
Authors: Pirri Angela , Toci Guido , Vannini Matteo
Published: April 2012

We present the performance of a laser prototype based on 1% at. Yb : Lu2O3 ceramic, longitudinally pumped in quasi-CW regime at 968 nm. A slope efficiency of 49% with respect to the absorbed pump power was obtained for laser operation at 1032.5 nm. We studied the effects on the laser oscillation due to the reinjection of the residual pump. The thermal behavior of the sample was investigated by means of numerical simulations, accounting for the different thermal load resulting from spontaneous and laser emission. Finally, we report the measured level of the Amplified Spontaneous Emission, which is found to be less than 0.1 mW.
Magnetic and Spectroscopic Studies of the Synthesized Metal Complexes of Bis(Pyridine‐2‐carbo) Hydrazide and Their Antimicrobial Studies
Authors: Singh Netra Pal , Anu  , Singh Jagvir
Published: April 2012

Cobalt(II), Nickel(II), Copper(II) and Manganese(II) complexes, having the general composition {M(L)2X2}, have been synthesized [where L= bis(pyridine‐2‐carbo) hydrazide(L), and X = Cl–]. All the Metal complexes reported here have been characterized by elemental analysis, molar conductance, magnetic moments, IR, electronic and mass spectral studies. All the complexes were found to have magnetic moments corresponding to unpaired electrons. The possible geometries of the complexes were assigned on the basis of electronic and infrared spectral studies. On the basis of molar conductance values the complexes show 1:2 electrolytic nature. Newly synthesized ligand and its Metal complexes have been screened against Staphylococcus aureus (ATCC 25923), Staphylococcus aureus (ATCC 3160) bacterial species and Candida albicans (227) and Staphylococcus cereviscae (361) fungal species.
System Identification Using Multilayer Differential Neural Networks: A New Result
Authors: Pérez-Cruz J. Humberto , Alanis A. Y. , Rubio José de Jesús , Pacheco Jaime
Published: April 2012

In previous works, a learning law with a dead zone function was developed for multilayer differential neural networks. This scheme requires strictly a priori knowledge of an upper bound for the unmodeled dynamics. In this paper, the learning law is modified in such a way that this condition is relaxed. By this modification, the tuning process is simpler and the dead‐zone function is not required anymore. On the basis of this modification and by using a Lyapunov‐like analysis, a stronger result is here demonstrated: the exponential convergence of the identification error to a bounded zone. Besides, a value for upper bound of such zone is provided. The workability of this approach is tested by a simulation example.
Photonic Crystal Fibers for Sensing Applications
Authors: Pinto Ana M. R. , Lopez-Amo Manuel
Published: April 2012

Photonic crystal fibers are a kind of fiber optics that present a diversity of new and improved features beyond what conventional optical fibers can offer. Due to their unique geometric structure, photonic crystal fibers present special properties and capabilities that lead to an outstanding potential for sensing applications. A review of photonic crystal fiber sensors is presented. Two different groups of sensors are detailed separately: physical and biochemical sensors, based on the sensor measured parameter. Several sensors have been reported until the date, and more are expected to be developed due to the remarkable characteristics such fibers can offer.
A Systematic Review of Xuezhikang, an Extract from Red Yeast Rice, for Coronary Heart Disease Complicated by Dyslipidemia
Authors: Shang Qinghua , Liu Zhaolan , Chen Keji , Xu Hao , Liu Jianping
Published: April 2012

Objective. This systematic review aims to evaluate the benefit and side effect of Xuezhikang for coronary heart disease (CHD) complicated by dyslipidemia.Methods. All randomized clinical trials (RCTs) with Xuezhikang as a treatment for CHD combined with dyslipidemia were considered for inclusion. Data extraction and analyses and quality assessment were conducted according to the Cochrane standards.Results. We included 22 randomized trials. Xuezhikang showed significant benefit on the incidence of all-cause deaths, CHD deaths, myocardial infarction, and revascularization as compared with placebo based on conventional treatment for CHD. It remarkably lowered total cholesterol (TC), triglyceride (TG), and low-density lipoprotein-cholesterol (LDL-C) as compared with the placebo or inositol nicotinate group, which was similar to statins group. Xuezhikang also raised high-density lipoprotein cholesterol (HDL-C) compared to placebo or no intervention, which was similar to Inositol nicotinate and slightly inferior to statins. The incidence of adverse events did not differ between the Xuezhikang and control group.Conclusions. Xuezhikang showed a comprehensive lipid-regulating effect and was safe and effective in reducing cardiovascular events in CHD patients complicated by dyslipidemia. However, more rigorous trials with high quality are needed to give high level of evidence.
A Facile Synthesis and Studies of Some New Chalcones and Their Derivatives Based on Heterocyclic Ring
Authors: Solankee A. , Patel K. , Patel R.
Published: April 2012

Chalcones (6a-f) have been prepared by the condensation of ketone (5) and different aromatic and heterocyclic aldehydes. These chalcones (6a-f) on treatment with guanidine hydrochloride and phenyl hydrazine hydrochloride in presence of alkali give aminopyrimidines (7a-f) and phenylpyrazolines (8a-f) respectively. All the newly synthesized compounds have been characterized on the basis of IR, 1HNMR spectral data as well as physical data. Antibacterial activity (minimum inhibitory concentration MIC) against Gram‐positive S. aureus MTCC 96 and S. pyogeneus MTCC 442 and Gram‐negative P. aeruginosa MTCC 1688 and E. coli MTCC 443 bacteria, as well as antifungal acivities (MIC) against C. albicans MTCC 227, A. niger MTCC 282 and A. clavatus MTCC 1323 were determined by broth dilution method.
Electromagnetic Field Coupling to Overhead Wire Configurations: Antenna Model versus Transmission Line Approach
Authors: Poljak Dragan , El Khamlichi Drissi Khalil
Published: April 2012

The paper deals with two different approaches for the analysis of electromagnetic field coupling to finite length overhead wire: the wire antenna theory (AT) and the transmission line (TL) method. The analysis is carried out in the frequency and time domain, respectively. Within the frequency domain analysis the wire antenna formulation deals with the corresponding set of Pocklington integrodifferential equation, while the transmission line model uses the telegrapher's equations. The set of Pocklington equations is solved via the Galerkin-Bubnov scheme of the Indirect Boundary Element Method (GB-IBEM), while the telegrapher’s equations are treated using the chain matrix method and the modal equation to derive per-unit-length parameters. For the case of the time domain analysis AT model uses the space-time Hallen integral equation set, while TL approach deals with the time domain version of the telegrapher’s equations. Hallen equations are handled via time domain version of GB-IBEM, while time domain telegrapher’s equations are solved by using Finite Difference Time Domain (FDTD) method. Many illustrative computational examples for the frequency and time domain response, respectively, for several configurations of overhead wires, obtained via different approaches, are given in this paper.
Porphyria Cutanea Tarda with Constrictive Pericarditis: A Rare Association
Authors: Jasleen Kaur , Sharma Nidhi , Kalsy Jyotika , Sharma Mughda
Published: April 2012

Porphyria cutanea tarda(PCT) is characterised by photosensitivity and bulla formation on photoexposed parts which heals with scaring and pigmentation. PCT is frequently associated with diabetes mellitus, lupus erythematosus and hepetitis C virus infection. We are reporting and Indian patient of PCT associated with pericarditis which is very rare.
A Risk Model for Lung Cancer Incidence
Authors: Hoggart Clive , Brennan Paul , Tjonneland Anne , Vogel Ulla , Overvad Kim , Østergaard Jane Nautrup , Kaaks Rudolf , Canzian Federico , Boeing Heiner , Steffen Annika , Trichopoulou Antonia , Bamia Christina , Trichopoulos Dimitrios , Johansson Mattias , Palli Domenico , Krogh Vittorio , Tumino Rosario , Sacerdote Carlotta , Panico Salvatore , Boshuizen Hendriek , Bueno-de-Mesquita H. Bas , Peeters Petra H.M. , Lund Eiliv , Gram Inger Torhild , Braaten Tonje , Rodríguez Laudina , Agudo Antonio , Sánchez-Cantalejo Emilio , Arriola Larraitz , Chirlaque Maria-Dolores , Barricarte Aurelio , Rasmuson Torgny , Khaw Kay-Tee , Wareham Nicholas , Allen Naomi E. , Riboli Elio , Vineis Paolo
Published: April 2012

Risk models for lung cancer incidence would be useful for prioritizing individuals for screening and participation in clinical trials of chemoprevention. We present a risk model for lung cancer built using prospective cohort data from a general population which predicts individual incidence in a given time period. We build separate risk models for current and former smokers using 169,035 ever smokers from the multicenter European Prospective Investigation into Cancer and Nutrition (EPIC) and considered a model for never smokers. The data set was split into independent training and test sets. Lung cancer incidence was modeled using survival analysis, stratifying by age started smoking, and for former smokers, also smoking duration. Other risk factors considered were smoking intensity, 10 occupational/environmental exposures previously implicated with lung cancer, and single-nucleotide polymorphisms at two loci identified by genome-wide association studies of lung cancer. Individual risk in the test set was measured by the predicted probability of lung cancer incidence in the year preceding last follow-up time, predictive accuracy was measured by the area under the receiver operator characteristic curve (AUC). Using smoking information alone gave good predictive accuracy: the AUC and 95% confidence interval in ever smokers was 0.843 (0.810–0.875), the Bach model applied to the same data gave an AUC of 0.775 (0.737–0.813). Other risk factors had negligible effect on the AUC, including never smokers for whom prediction was poor. Our model is generalizable and straightforward to implement. Its accuracy can be attributed to its modeling of lifetime exposure to smoking. Cancer Prev Res; 5(6); 834–46. ©2012 AACR.
A Novel Taspine Derivative, HMQ1611, Inhibits Breast Cancer Cell Growth via Estrogen Receptor α and EGF Receptor Signaling Pathways
Authors: Zhan Yingzhuan , Zhang Yanmin , Liu Cuicui , Zhang Jie , Smith Wanli W. , Wang Nan , Chen Yinnan , Zheng Lei , He Langchong
Published: April 2012

Breast cancer is a common cancer with a leading cause of cancer mortality in women. Currently, the chemotherapy for breast cancer is underdeveloped. Here, we report a novel taspine derivative, HMQ1611, which has anticancer effects using in vitro and in vivo breast cancer models. HMQ1611 reduced cancer cell proliferation in four human breast cancer cell lines including MDA-MB-231, SK-BR-3, ZR-75-30, and MCF-7. HMQ1611 more potently reduced growth of estrogen receptor α (ERα)-positive breast cancer cells (ZR-75-30 and MCF-7) than ERα-negative cells (MDA-MB-231 and SK-BR-3). Moreover, HMQ1611 arrested breast cancer cell cycle at S-phase. In vivo tumor xenograft model, treatment of HMQ1611 significantly reduced tumor size and weight compared with vehicles. We also found that HMQ1611 reduced ERα expression and inhibited membrane ERα-mediated mitogen—activated protein kinase (MAPK) signaling following the stimulation of cells with estrogen. Knockdown of ERα by siRNA transfection in ZR-75-30 cells attenuated HMQ1611 effects. In contrast, overexpression of ERα in MDA-MB-231 cells enhanced HMQ1611 effects, suggesting that ERα pathway mediated HMQ1611′s inhibition of breast cancer cell growth in ERα-positive breast cancer. HMQ1611 also reduced phosphorylation of EGF receptor (EGFR) and its downstream signaling players extracellular signal—regulated kinase (ERK)1/2 and AKT activation both in ZR-75-30 and MDA-MB-231 cells. These results showed that the novel compound HMQ1611 had anticancer effects, and partially via ERα and/or EGFR signaling pathways, suggesting that HMQ1611 may be a potential novel candidate for human breast cancer intervention. Cancer Prev Res; 5(6); 864–73. ©2012 AACR.
Chronic Inhibition of cGMP Phosphodiesterase 5A Improves Diabetic Cardiomyopathy
Authors: Giannetta Elisa , Isidori Andrea M. , Galea Nicola , Carbone Iacopo , Mandosi Elisabetta , Vizza Carmine D. , Naro Fabio , Morano Susanna , Fedele Francesco , Lenzi Andrea
Published: April 2012

Background—

cGMP phosphodiesterase type 5 protein is upregulated in myocardial hypertrophy. However, it has never been ascertained whether phosphodiesterase type 5 inhibition exerts an antiremodeling effect in nonischemic heart disease in humans. We explored the cardioreparative properties of a selective phosphodiesterase type 5 inhibitor, sildenafil, in a model of diabetic cardiomyopathy.

Methods and Results—

Fifty-nine diabetic men (60.3±7.4 years) with cardiac magnetic resonance imaging consistent with nonischemic, nonfailing diabetic cardiomyopathy (reduced circumferential strain [σ], −12.6±3.1; increased left ventricular [LV] torsion [θ], 18.4±4.6°; and increased ratio of LV mass to volume, 2.1±0.5 g/mL) were randomized to receive sildenafil or placebo (100 mg/d). At baseline, the metabolic indices were correlated with torsion, strain, N-terminal pro–B-type natriuretic peptide, vascular endothelial growth factor, monocyte chemotactic protein-1, and blood pressure. After 3 months, sildenafil produced a significant improvement compared with placebo in LV torsion (Δθ: sildenafil, −3.89±3.11° versus placebo, 2.13±2.35°;
P
<0.001) and strain (Δσ: sildenafil, −3.30±1.86 versus placebo, 1.22±1.84;
P
<0.001). Sildenafil-induced improvement of LV contraction was accompanied by consistent changes in chamber geometry and performance, with a 6.5±11 improvement in mass-to-volume ratio over placebo (
P
=0.021). Monocyte chemotactic protein-1 and transforming growth factor-β were the only markers affected by active treatment (Δmonocyte chemotactic protein-1: −75.30±159.28 pg/mL,
P
=0.032; Δtransforming growth factor-β: 5.26±9.67 ng/mL,
P
=0.009). No changes were found in endothelial function, afterload, or metabolism.

Conclusions—

The early features of diabetic cardiomyopathy are LV concentric hypertrophy associated with altered myocardial contraction dynamics. Chronic phosphodiesterase type 5 inhibition, at this stage, has an antiremodeling effect, resulting in improved cardiac kinetics and circulating markers. This effect is independent of any other vasodilatory or endothelial effects and is apparently exerted through a direct intramyocardial action.

Clinical Trial Registration—

URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT00692237.