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Diffusion Coefficients of Copper Chloride in Aqueous Solutions at 298.15 K and 310.15 K

Ribeiro, Ana C. F.; Esteso, Miguel A.; Lobo, Victor M. M.; Valente, Artur J. M.; Simões, Susana M. N.; Sobral, Abilio J. F. N.; Burrows, Hugh D.
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
26.75%
Mutual diffusion coefficients (interdiffusion coefficients) and molar conductivities have been measured for copper(II) chloride in water at 298.15 K and 310.15 K at concentrations between 0.005 mol·dm-3 and 0.05 mol·dm-3. The diffusion coefficients were measured using a conductometric cell. The experimental data are discussed on the basis of the Onsager−Fuoss model. The Nernst diffusion coefficients derived from diffusion (1.297 × 10-9 and 1.690 × 10-9) m2·s-1 and from conductance (1.282 × 10-9 and 1.663 × 10-9) m2·s-1 at two temperatures (298.15 K and 310.15 K, respectively) are in good agreement.; http://dx.doi.org/10.1021/je050220y

Mapeamento do potencial de instabilização de taludes rodoviários usando SIG e seções geológico-geotécnicas de campo com aplicação na rodovia SP-310; Mapping of the potential of instabilization of road slopes using Sig and geological-geotecnical sections of field with application in highway SP-310

Lopes, Ana Paula Rodrigues
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 14/09/2007 PT
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26.89%
O presente estudo desenvolveu uma metodologia para mapeamento de potencial de instabilização de taludes rodoviários. Utilizou-se, para tanto, SIG (Sistema de Informações Geográficas) e seções geológico-geotécnicas de detalhe obtidas em levantamentos de superfície. Esta metodologia foi utilizada em trecho da Rodovia Washington Luís (SP-310), sob duas condições distintas. Inicialmente, foi aplicada à totalidade da área estudada a ponderação dos atributos de percentual de declividade, materiais inconsolidados, curvatura de encostas e direção de vertentes, obtendo-se o mapa de potencial de instabilização. Na faixa da ADA (área diretamente afetada da rodovia - com 50 m de largura), esta metodologia deu especial ênfase às seções geológico-geotécnicas, que permitiram uma melhor compreensão da geometria dos taludes de corte e aterro e disposição dos materiais inconsolidados e foram utilizadas como critérios para a compartimentação destes taludes resultando no mapa de potencial de acidente. Outros produtos cartográficos deste estudo são os mapas hipsométrico, de declividade, de curvatura de encostas, de direção de vertentes e de materiais inconsolidados que serviram de base para a realização dos mapas de potencial de instabilização e de acidente...

Enhanced Virulence Mediated by the Murine Coronavirus, Mouse Hepatitis Virus Strain JHM, Is Associated with a Glycine at Residue 310 of the Spike Glycoprotein

Ontiveros, Evelena; Kim, Taeg S.; Gallagher, Thomas M.; Perlman, Stanley
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /10/2003 EN
Relevância na Pesquisa
26.75%
The coronavirus, mouse hepatitis virus strain JHM, causes acute and chronic neurological diseases in rodents. Here we demonstrate that two closely related virus variants, both of which cause acute encephalitis in susceptible strains of mice, cause markedly different diseases if mice are protected with a suboptimal amount of an anti-JHM neutralizing antibody. One strain, JHM.SD, caused acute encephalitis, while infection with JHM.IA resulted in no acute disease. Using recombinant virus technology, we found that the differences between the two viruses mapped to the spike (S) glycoprotein and that the two S proteins differed at four amino acids. By engineering viruses that differed by only one amino acid, we identified a serine-to-glycine change at position 310 of the S protein (S310G) that recapitulated the more neurovirulent phenotype. The increased neurovirulence mediated by the virus encoding glycine at position S310 was not associated with a different tropism within the central nervous system (CNS) but was associated with increased lateral spread in the CNS, leading to significantly higher brain viral titers. In vitro studies revealed that S310G was associated with decreased S1-S2 stability and with enhanced ability to mediate infection of cells lacking the primary receptor for JHM (“receptor-independent spread”). These enhanced fusogenic properties of viruses encoding a glycine at position 310 of the S protein may contribute to spread within the CNS...

A gamma methionine-310 to threonine substitution and consequent N-glycosylation at gamma asparagine-308 identified in a congenital dysfibrinogenemia associated with posttraumatic bleeding, fibrinogen Asahi.

Yamazumi, K; Shimura, K; Terukina, S; Takahashi, N; Matsuda, M
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /05/1989 EN
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26.75%
In an abnormal fibrinogen with severely impaired polymerization of fibrin monomers, we identified a methionine-to-threonine substitution at position 310 of the gamma chain. Furthermore, asparagine at position 308 was found to be N-glycosylated due to a newly formed consensus sequence, asparagine(308)-glycine(309)-threonine(310). The two structural defects in the mutant gamma chain may well perturb the conformation required for fibrin monomer polymerization that is specifically assigned to the D domain of fibrinogen. This alteration also seems to affect the intermolecular gamma chain cross-linking of fibrin and fibrinogen, although the amine acceptor gamma glutamine-398 was found to function normally. These functional abnormalities may well be related to posttraumatic hemorrhage as observed in a 33-yr-old man with moderate hemorrhagic diathesis related to injuries since his early adolescence. The structure of the extra carbohydrate moiety attached to asparagine-308 was found to be identical with those derived from the normal B beta and gamma chains as evidenced by HPLC.

Long polypeptide 310-helices at atomic resolution

Bavoso, Alfonso; Benedetti, Ettore; Di Blasio, Benedetto; Pavone, Vincenzo; Pedone, Carlo; Toniolo, Claudio; Bonora, Gian Maria
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /04/1986 EN
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26.98%
The crystal-state preferred conformation of the terminally blocked homooctapeptide from the Cα,α-dimethylated α-aminoisobutyric acid (Aib) residue, pBrBz-(Aib)8-OBut, in which pBrBz is para-bromobenzoyl and OBut is tert-butoxy, determined by x-ray diffraction analysis using direct methods, was found to be a 310-helix stabilized by six consecutive intramolecular N—H....O=C hydrogen bonds of the C10-III (or III′) type. This is the first observation at atomic resolution of a regular 310-helix longer than two complete turns. The solid-state structural analysis was extended to the terminally blocked, α-aminoisobutyric acid-rich octapeptide corresponding to the 2-9 sequence of the peptaibol antibiotics emerimicins III and IV, pBrBz-Aib3-L-Val-Gly-L-Leu-Aib2-OMe. Again, this peptide adopts a (right-handed) 310-helical structure, although slightly distorted at the level of the L-leucine residue. The role of specific amino acid sequence and peptide main-chain length in stabilizing either the 310- or the α-helical conformation and their possible implications on the nature of the channel formed by peptaibol antibiotics in the membrane are also briefly discussed.

Substitution of aspartic acid for glycine at position 310 in type II collagen produces achondrogenesis II, and substitution of serine at position 805 produces hypochondrogenesis: analysis of genotype-phenotype relationships.

Bonaventure, J; Cohen-Solal, L; Ritvaniemi, P; Van Maldergem, L; Kadhom, N; Delezoide, A L; Maroteaux, P; Prockop, D J; Ala-Kokko, L
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 01/05/1995 EN
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26.75%
Two different mutations were found in two unrelated probands with lethal chondrodysplasias, one with achondrogenesis type II and the other with the less severe phenotype of hypochondrogenesis. The mutations in the COL2A1 gene were identified by denaturing gradient gel electrophoresis analysis of genomic DNA followed by dideoxynucleotide sequencing and restriction site analysis. The proband with achondrogenesis type II had a heterozygous single-base mutation that substituted aspartate for glycine at position 310 of the alpha 1(II) chain of type II procollagen. The proband with hypochondrogenesis had a heterozygous single-base mutation that substituted serine for glycine at position 805. Type II collagen extracted from cartilage from the probands demonstrated the presence of type I collagen and a delayed electrophoretic mobility, indicating post-translational overmodifications. Analysis of CNBr peptides showed that, in proband 1, the entire peptides were overmodified. Examination of chondrocytes cultured in agarose or alginate indicated that there was a delayed secretion of type II procollagen. In addition, type II collagen synthesized by cartilage fragments from the probands demonstrated a decreased thermal stability. The melting temperature of the type II collagen containing the aspartate-for-glycine substitution was reduced by 4 degrees C...

Phosphorylation of Gata1 at serine residues 72, 142, and 310 is not essential for hematopoiesis in vivo

Rooke, Heather M.; Orkin, Stuart H.
Fonte: The American Society of Hematology Publicador: The American Society of Hematology
Tipo: Artigo de Revista Científica
Publicado em 01/05/2006 EN
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26.98%
Phosphorylation of transcription factors is important in posttranslational control of protein function. The indispensable zinc-finger transcription factor, Gata1, is phosphorylated constitutively at 6 serine residues (26, 49, 72, 142, 178, 187), and at a seventh (310) following induction of erythroid differentiation. However, the biologic consequences of phosphorylation with respect to function are unclear. To address this issue, we generated mice with serine-to-alanine mutations at the inducibly phosphorylated serine 310 alone or at conserved serine residues 72, 142, and 310 together. The peripheral blood parameters of the mice were normal, as was their response to acute erythropoietic stress. Analysis of hematopoietic progenitor populations during ontogeny and into adulthood showed a moderate decrease in erythroid burst-forming unit (BFU-E) and erythroid colony-forming unit (CFU-E) numbers only in the adult bone marrow of the triple mutant. Yet, later stage erythropoiesis was not perturbed. This suggests that any molecular consequences associated with loss of phosphorylation at residues 72, 142, and 310 can be compensated for in the in vivo environment.

The role of α-, 310-, and π-helix in helix→coil transitions

Armen, Roger; Alonso, Darwin O.V.; Daggett, Valerie
Fonte: Cold Spring Harbor Laboratory Press Publicador: Cold Spring Harbor Laboratory Press
Tipo: Artigo de Revista Científica
Publicado em /06/2003 EN
Relevância na Pesquisa
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The conformational equilibrium between 310- and α-helical structure has been studied via high-resolution NMR spectroscopy by Millhauser and coworkers using the MW peptide Ac-AMAAKAWAAKA AAARA-NH2. Their 750-MHz nuclear Overhauser effect spectroscopy (NOESY) spectra were interpreted to reflect appreciable populations of 310-helix throughout the peptide, with the greatest contribution at the N and C termini. The presence of simultaneous αN(i,i + 2) and αN(i,i + 4) NOE cross-peaks was proposed to represent conformational averaging between 310- and α-helical structures. In this study, we describe 25-nsec molecular dynamics simulations of the MW peptide at 298 K, using both an 8 Å and a 10 Å force-shifted nonbonded cutoff. The ensemble averages of both simulations are in reasonable agreement with the experimental helical content from circular dichroism (CD), the 3JHNα coupling constants, and the 57 observed NOEs. Analysis of the structures from both simulations revealed very little formation of contiguous i → i + 3 hydrogen bonds (310-helix); however, there was a large population of bifurcated i → i + 3 and i → i + 4 α-helical hydrogen bonds. In addition, both simulations contained considerable populations of π-helix (i → i + 5 hydrogen bonds). Individual turns formed over residues 1–9...

Energy landscape of a peptide consisting of α-helix, 310-helix, β-turn, β-hairpin, and other disordered conformations

Higo, Junichi; Ito, Nobutoshi; Kuroda, Masataka; Ono, Satoshi; Nakajima, Nobuyuki; Nakamura, Haruki
Fonte: Cold Spring Harbor Laboratory Press Publicador: Cold Spring Harbor Laboratory Press
Tipo: Artigo de Revista Científica
Publicado em /06/2001 EN
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26.75%
The energy landscape of a peptide [Ace-Lys-Gln-Cys-Arg-Glu-Arg-Ala-Nme] in explicit water was studied with a multicanonical molecular dynamics simulation, and the AMBER parm96 force field was used for the energy calculation. The peptide was taken from the recognition helix of the DNA-binding protein, c-Myb. A rugged energy landscape was obtained, in which the random-coil conformations were dominant at room temperature. The CD spectra of the synthesized peptide revealed that it is in the random state at room temperature. However, the 300 K canonical ensemble, Q(300K), contained α-helix, 310-helix, β-turn, and β-hairpin structures with small but notable probabilities of existence. The complete α-helix, imperfect α-helix, and random-coil conformations were separated from one another in the conformational space. This means that the peptide must overcome energy barriers to form the α-helix. The overcoming process may correspond to the hydrogen-bond rearrangements from peptide–water to peptide–peptide interactions. The β-turn, imperfect 310-helix, and β-hairpin structures, among which there are no energy barriers at 300 K, were embedded in the ensemble of the random-coil conformations. Two types of β-hairpin with different β-turn regions were observed in Q(300K). The two β-hairpin structures may have different mechanisms for the β-hairpin formation. The current study proposes a scheme that the random state of this peptide consists of both ordered and disordered conformations. In contrast...

Akt Cys-310-targeted Inhibition by Hydroxylated Benzene Derivatives Is Tightly Linked to Their Immunosuppressive Effects*

Lee, Ji Yeon; Lee, Yong Gyu; Lee, Jaehwi; Yang, Keum-Jin; Kim, Ae Ra; Kim, Joo Young; Won, Moo-Ho; Park, Jongsun; Yoo, Byong Chul; Kim, Sanghee; Cho, Won-Jea; Cho, Jae Youl
Fonte: American Society for Biochemistry and Molecular Biology Publicador: American Society for Biochemistry and Molecular Biology
Tipo: Artigo de Revista Científica
EN
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26.75%
The hydroxylated benzene metabolite hydroquinone (HQ) is mainly generated from benzene, an important industrial chemical, and is also a common dietary component. Although numerous reports have addressed the tumorigenesis-inducing effects of HQ, few papers have explored its molecular regulatory mechanism in immunological responses. In this study we characterized Akt (protein kinase B)-targeted regulation by HQ and its derivatives, in suppressing inflammatory responses using cellular, molecular, biochemical, and immunopharmacological approaches. HQ down-regulated inflammatory responses such as NO production, surface levels of pattern recognition receptors, and cytokine gene expression with IC50 values that ranged from 5 to 10 μm. HQ inhibition was mediated by blocking NF-κB activation via suppression of its translocation pathway, which is composed of Akt, IκBα kinase β, and IκBα. Of the targets in this pathway, HQ directly targeted and bound to the sulfhydryl group of Cys-310 of Akt and sequentially interrupted the phosphorylation of both Thr-308 and Ser-473 by mediation of β-mercaptoethanol, according to the liquid chromatography/mass spectroscopy analysis of the interaction of HQ with an Akt-derived peptide. Therefore, our data suggest that Akt and its target site Cys-310 can be considered as a prime molecular target of HQ-mediated immunosuppression and for novel anti-Akt-targeted immunosuppressive drugs.

The Drosophila miR-310 cluster negatively regulates synaptic strength at the neuromuscular junction

Tsurudome, Kazuya; Tsang, Karen; Liao, Edward H.; Ball, Robin; Penney, Jay; Yang, Jr-Shiuan; Elazzouzi, Fatima; He, Tao; Chishti, Athar; Lnenicka, Greg; Lai, Eric C.; Haghighi, A. Pejmun
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 09/12/2010 EN
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27.1%
Emerging data implicate microRNAs (miRNAs) in the regulation of synaptic structure and function, but we know little about their role in the regulation of neurotransmission in presynaptic neurons. Here we demonstrate that the miR-310-313 cluster is required for normal synaptic transmission at the Drosophila larval neuromuscular junction. Loss of miR-310-313 cluster leads to a significant enhancement of neurotransmitter release, which can be rescued with temporally restricted expression of mir-310-313 in larval presynaptic neurons. Kinesin family member, Khc-73 is a functional target for miR-310-313 as its expression is increased in mir-310-313 mutants and reducing it restores normal synaptic function. Cluster mutants show an increase in the active zone protein Bruchpilot accompanied by an increase in electron dense T-bars. Finally, we show that repression of Khc-73 by miR-310-313 cluster influences the establishment of normal synaptic homeostasis. Our findings establish a role for miRNAs in the regulation of neurotransmitter release.

310-Helix Conformation Facilitates the Transition of a Voltage Sensor S4 Segment toward the Down State

Schwaiger, Christine S.; Bjelkmar, Pär; Hess, Berk; Lindahl, Erik
Fonte: The Biophysical Society Publicador: The Biophysical Society
Tipo: Artigo de Revista Científica
Publicado em 16/03/2011 EN
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27.1%
The activation of voltage-gated ion channels is controlled by the S4 helix, with arginines every third residue. The x-ray structures are believed to reflect an open-inactivated state, and models propose combinations of translation, rotation, and tilt to reach the resting state. Recently, experiments and simulations have independently observed occurrence of 310-helix in S4. This suggests S4 might make a transition from α- to 310-helix in the gating process. Here, we show 310-helix structure between Q1 and R3 in the S4 segment of a voltage sensor appears to facilitate the early stage of the motion toward a down state. We use multiple microsecond-steered molecular simulations to calculate the work required for translating S4 both as α-helix and transformed to 310-helix. The barrier appears to be caused by salt-bridge reformation simultaneous to R4 passing the F233 hydrophobic lock, and it is almost a factor-two lower with 310-helix. The latter facilitates translation because R2/R3 line up to face E183/E226, which reduces the requirement to rotate S4. This is also reflected in a lower root mean-square deviation distortion of the rest of the voltage sensor. This supports the 310 hypothesis, and could explain some of the differences between the open-inactivated- versus activated-states.

The miR-310/13 cluster antagonizes β-catenin function in the regulation of germ and somatic cell differentiation in the Drosophila testis

Pancratov, Raluca; Peng, Felix; Smibert, Peter; Yang, Jr-Shiuan; Olson, Emily Ruth; Guha-Gilford, Ciaran; Kapoor, Amol J.; Liang, Feng-Xia; Lai, Eric C.; Flaherty, Maria Sol; DasGupta, Ramanuj
Fonte: Company of Biologists Publicador: Company of Biologists
Tipo: Artigo de Revista Científica
Publicado em 15/07/2013 EN
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27.05%
MicroRNAs (miRNAs) are regulators of global gene expression and function in a broad range of biological processes. Recent studies have suggested that miRNAs can function as tumor suppressors or oncogenes by modulating the activities of evolutionarily conserved signaling pathways that are commonly dysregulated in cancer. We report the identification of the miR-310 to miR-313 (miR-310/13) cluster as a novel antagonist of Wingless (Drosophila Wnt) pathway activity in a functional screen for Drosophila miRNAs. We demonstrate that miR-310/13 can modulate Armadillo (Arm; Drosophila β-catenin) expression and activity by directly targeting the 3′-UTRs of arm and pangolin (Drosophila TCF) in vivo. Notably, the miR-310/13-deficient flies exhibit abnormal germ and somatic cell differentiation in the male gonad, which can be rescued by reducing Arm protein levels or activity. Our results implicate a previously unrecognized function for miR-310/13 in dampening the activity of Arm in early somatic and germline progenitor cells, whereby inappropriate/sustained activation of Arm-mediated signaling or cell adhesion may impact normal differentiation in the Drosophila male gonad.

Validação do equipamento Tanita TBF-310 na estimação da composição corporal tendo como referência um modelo molecular a quarto compartimentos em judocas

Domingos, Christophe dos Santos
Fonte: Universidade Técnica de Lisboa Publicador: Universidade Técnica de Lisboa
Tipo: Dissertação de Mestrado
Publicado em //2015 POR
Relevância na Pesquisa
37.1%
A avaliação da composição corporal, especialmente ao nível das componentes moleculares,é relevante para a população atlética pela sua relação com o desempenho desportivo. Sabe-se que o modelo molecular a quatro compartimentos (4C) é o método de referência na avaliação da massa gorda (MG). No entanto, a sua implementação em contexto real é impraticável. Deste modo, treinadores e atletas procuram informar-se sobre a composição corporal usando os métodos mais acessíveis, onde a bioimpedância elétrica (BIA) se engloba, e mais ainda em desportos onde o peso é seletivo para a competição, como é o caso dos desportos de combate. A literatura mostra que existem diversas equações e equipamentos que utilizam a BIA mas poucos estudos foram conduzidos para determinar a sua validade na população atlética. O objectivo deste estudo é determinar a validade da BIA (Tanita, modelo TBF-310) na determinação da MG e massa isenta de gordura (MIG) em judocas de elite. Um total de 29 atletas, do sexo masculino, foram avaliados num período de estabilidade do peso entre Setembro e Outubro pelo método de referência (4C) e método alternativo (Tanita). Realizaram-se comparações de médias, coeficiente de correlação de concordância...

Rapid and multi-band variability of the TeV-bright active nucleus of the galaxy IC 310

The MAGIC Collaboration; Aleksić, J.; Antonelli, L. A.; Antoranz, P.; Babic, A.; de Almeida, U. Barres; Barrio, J. A.; González, J. Becerra; Bednarek, W.; Berger, K.; Bernardini, E.; Biland, A.; Blanch, O.; Bock, R. K.; Boller, A.; Bonnefoy, S.; Bonnoli
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
27.05%
Context. The radio galaxy IC 310 has recently been identified as a gamma-ray emitter based on observations at GeV energies with Fermi-LAT and at very high energies (VHE, E>100GeV) with the MAGIC telescopes. Originally classified as a head-tail radio galaxy, the nature of this object is subject of controversy since its nucleus shows blazar-like behavior. Aims. In order to understand the nature of IC 310 and the origin of the VHE emission we studied the spectral and flux variability of IC 310 from the X-ray band to the VHE gamma-ray regime. Methods. The light curve of IC 310 above 300GeV has been measured with the MAGIC telescopes from Oct. 2009 to Feb. 2010. Fermi-LAT data (2008-2011) in the 10-500GeV energy range were also analyzed. In X-ray, archival observations from 2003 to 2007 with XMM, Chandra, and Swift-XRT in the 0.5-10keV band were studied. Results. The VHE light curve reveals several high-amplitude and short-duration flares. Day-to-day flux variability is clearly present. The photon index between 120GeV and 8TeV remains at the value $\Gamma\sim2.0$ during both low and high flux states. The VHE spectral shape does not show significant variability, whereas the flux at 1TeV changes by a factor of $\sim7$. Fermi-LAT detected only eight gamma-ray events in the energy range 10GeV-500GeV in three years of observation. The measured photon index of $\Gamma=1.3\pm0.5$ in the Fermi-LAT range is very hard. The X-ray measurements show strong variability in flux and photon index. The latter varied from $1.76\pm0.07$ to $2.55\pm0.07$. Conclusion. The rapid variability measured confirms the blazar-like behavior of IC 310. The TeV emission seems to originate from scales of less than 80 Schwarzschild radii within the compact core of its FRI radio jet with orientation angle 10deg-38deg. The SED resembles that of an extreme blazar...

XMM-Newton Observation of IC 310 in the Outer Region of the Perseus Cluster of Galaxies

Sato, K.; Furusho, T.; Yamasaki, N. Y.; Ishida, M.; Matsushita, K.; Ohashi, T.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
27.1%
We present results from an XMM-Newton observation of the head-tail radio galaxy IC 310 located in the southwest region of the Perseus cluster. The spectrum is well-fitted by an absorbed power-law model with a photon index of $2.50 \pm 0.02$ with no significant absorption excess. The X-ray image shows a point-like emission at IC 310 without any signs of a structure correlated with the radio halo tail. The temperature of the intracluster medium surrounding IC 310 declines as a function of distance from the cluster center, from $ kT \sim 6$ keV in the northeast corner of the field of view to about 3 keV in the southwest region. Although we do not find any sharp edges in the surface brightness profile, a brightness excess over a smooth $\beta$ model by about 20% is seen. The temperature also rises by about 10% in the same region. This indicates that the IC 310 region is a subcluster probably infalling into the Perseus cluster, and the gas in front of IC 310 towards the Perseus cluster is likely to be compressed by the large-scale motion, which supports the view that the IC 310 system is undergoing a merger.; Comment: 7 pages, 8 figures (including color), accepted for publication in PASJ

Black Hole Lightning from the Peculiar Gamma-Ray Loud Active Galactic Nucleus IC 310

Glawion, Dorit Eisenacher; Sitarek, Julian; Mannheim, Karl; Colin, Pierre; Collaboration, for the MAGIC; Kadler, Matthias; Schulz, Robert; Ros, Eduardo; Bach, Uwe; Krauß, Felicia; Wilms, Jörn
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 20/08/2015
Relevância na Pesquisa
26.89%
The nearby active galaxy IC 310, located in the outskirts of the Perseus cluster of galaxies is a bright and variable multi-wavelength emitter from the radio regime up to very high gamma-ray energies above 100 GeV. Originally, the nucleus of IC 310 has been classified as a radio galaxy. However, studies of the multi-wavelength emission showed several properties similarly to those found from blazars as well as radio galaxies. In late 2012, we have organized the first contemporaneous multi-wavelength campaign including radio, optical, X-ray and gamma-ray instruments. During this campaign an exceptionally bright flare of IC 310 was detected with the MAGIC telescopes in November 2012 reaching an averaged flux level in the night of up to one Crab above 1 TeV with a hard spectrum over two decades in energy. The intra-night light curve showed a series of strong outbursts with flux-doubling time scales as fast as a few minutes. The fast variability constrains the size of the gamma-ray emission regime to be smaller than 20% of the gravitational radius of its central black hole. This challenges the shock acceleration models, commonly used to explain gamma-ray radiation from active galaxies. Here, we will present more details on the MAGIC data and discuss several possible alternative emission models.; Comment: 8 pages...

Insights into the particle acceleration of a peculiar gamma -ray radio galaxy IC 310

Sitarek, J.; Glawion, D. Eisenacher; Mannheim, K.; Colin, P.; Collaboration, for the MAGIC; Kadler, M.; Schultz, R.; Krauß, F.; Ros, E.; Bach, U.; Wilms, J.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 04/02/2015
Relevância na Pesquisa
26.89%
IC 310 has recently been identified as a gamma-ray emitter based on observations at GeV energies with Fermi-LAT and at very high energies (VHE, E > 100 GeV) with the MAGIC telescopes. Despite IC 310 having been classified as a radio galaxy with the jet observed at an angle > 10 degrees, it exhibits a mixture of multiwavelength properties of a radio galaxy and a blazar, possibly making it a transitional object. On the night of 12/13th of November 2012 the MAGIC telescopes observed a series of violent outbursts from the direction of IC 310 with flux-doubling time scales faster than 5 min and a peculiar spectrum spreading over 2 orders of magnitude. Such fast variability constrains the size of the emission region to be smaller than 20% of the gravitational radius of its central black hole, challenging the shock acceleration models, commonly used in explanation of gamma-ray radiation from active galaxies. Here we will show that this emission can be associated with pulsar-like particle acceleration by the electric field across a magnetospheric gap at the base of the jet.; Comment: 2014 Fermi Symposium proceedings - eConf C14102.1

The Aftermath of an Exceptional TeV Flare in the AGN Jet of IC 310

Eisenacher, Dorit; Colin, Pierre; Lombardi, Saverio; Sitarek, Julian; Zandanel, Fabio; Prada, Francisco; Linfors, Elina; Paneque, David; Elsässer, Dominik; Mannheim, Karl; Collaboration, for the MAGIC; Müller, Cornelia; Collaboration, for the Fermi-LAT;
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 02/08/2013
Relevância na Pesquisa
26.89%
The nearby active galaxy IC 310 (z=0.019), located in the Perseus cluster of galaxies is a bright and variable multi-wavelength emitter from the radio regime up to very high gamma-ray energies above 100 GeV. Very recently, a blazar-like compact radio jet has been found by parsec-scale VLBI imaging. Along with the unusually flat gamma-ray spectrum and variable high-energy emission, this suggests that IC 310 is the closest known blazar and therefore a key object for AGN research. As part of an intense observing program at TeV energies with the MAGIC telescopes, an exceptionally bright flare of IC 310 was detected in November 2012 reaching a flux level of up to >0.5 Crab units above 300 GeV. We have organized a multi-wavelength follow-up program, including the VLBA, Effelsberg 100 m, KVA, Swift, INTEGRAL, Fermi/LAT, and the MAGIC telescopes. We present preliminary results from the multi-wavelength follow-up program with the focus on the response of the jet to this exceptional gamma-ray flare.; Comment: Proceedings of the 33rd ICRC 2013, Rio de Janeiro, contribution #336

The EVN view of the highly variable TeV active galaxy IC 310

Schulz, R.; Kadler, M.; Ros, E.; Glawion, D. Eisenacher; Bach, U.; Elsässer, D.; Grossberger, C.; Kreykenbohm, I.; Mannheim, K.; Müller, C.; Trüstedt, J.; Wilms, J.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 12/02/2015
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Very-high-energy $\gamma$-ray observations of the active galaxy IC 310 with the MAGIC telescopes have revealed fast variability with doubling time scales of less than 4.8min. This implies that the emission region in IC 310 is smaller than 20% of the gravitational radius of the central supermassive black hole with a mass of $3\times 10^8 M_\odot$, which poses serious questions on the emission mechanism and classification of this enigmatic object. We report on the first quasi-simultaneous multi-frequency VLBI observations of IC 310 conducted with the EVN. We find a blazar-like one-sided core-jet structure on parsec scales, constraining the inclination angle to be less than $\sim 20^\circ$ but very small angles are excluded to limit the de-projected length of the large-scale radio jet.; Comment: 4 pages, proceedings of the 12th European VLBI Network Symposium and Users Meeting - EVN 2014, 7-10 October 2014, Cagliari, Italy. Published online in PoS, ID.109