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Uma reflexão histórica e crítica sobre música e educação: análise do projeto de lei do Senado n. 330 de 2006 que deu origem à Lei n. 11.769, de 18 de agosto de 2008

Gonçalves, Paula Cristina da Silva
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Trabalho de Conclusão de Curso Formato: 147 f.
Português
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26.68%
The objective of this study is to analyze the trajectory of the bill the Senate No. 330 of 2006 that led to Law no. 11,769 of 18 August 2008, amending Article 26 of the Law of Directives and Bases of Education (Act 9394 of 1996) to be held about the mandatory teaching of music in primary education, after more than 30 years of absence from the scene national public education, until to be sanctioned with partial veto, noting the historical importance of this artistic aspect as widely performed in various ways and for many different purposes. The return of the compulsory teaching of music reappears in the realms of teaching systematized public by bringing the possibility of thinking about music, see it beyond the medias execute that permeate society today.; O objeto deste trabalho é analisar a trajetória do Projeto de Lei do Senado N° 330 de 2006 que deu origem à Lei Nº. 11.769 de 1 8 de agosto de 2008, que altera o artigo 26 da Lei de Diretrizes e Bases da Educação (Lei 9.394 de 1996) para dispor a respeito da obrigatoriedade do ensino da música na educação básica, após mais de 30 anos de ausência no cenário educativo nacional público, até ser sancionado com veto parcial, destacando a importância histórica dessa vertente artística tão amplamente executada nas mais variadas formas e para as mais variadas finalidades. O retorno do ensino obrigatório da música ressurge nas esferas do ensino sistematizado público trazendo a possibilidade de pensar a música...

A 330 kb CENP-A binding domain and altered replication timing at a human neocentromere

Lo, Anthony W.I.; Craig, Jeffrey M.; Saffery, Richard; Kalitsis, Paul; Irvine, Danielle V.; Earle, Elizabeth; Magliano, Dianna J.; Choo, K.H.Andy
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
Publicado em 17/04/2001 Português
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Centromere protein A (CENP-A) is an essential centromere-specific histone H3 homologue. Using combined chromatin immunoprecipitation and DNA array analysis, we have defined a 330 kb CENP-A binding domain of a 10q25.3 neocentromere found on the human marker chromosome mardel(10). This domain is situated adjacent to the 80 kb region identified previously as the neocentromere site through lower-resolution immunofluorescence/FISH analysis of metaphase chromosomes. The 330 kb CENP-A binding domain shows a depletion of histone H3, providing evidence for the replacement of histone H3 by CENP-A within centromere-specific nucleosomes. The DNA within this domain has a high AT-content comparable to that of α-satellite, a high prevalence of LINEs and tandem repeats, and fewer SINEs and potential genes than the surrounding region. FISH analysis indicates that the normal 10q25.3 genomic region replicates around mid-S phase. Neocentromere formation is accompanied by a replication time lag around but not within the CENP-A binding region, with this lag being significantly more prominent to one side. The availability of fully sequenced genomic markers makes human neocentromeres a powerful model for dissecting the functional domains of complex higher eukaryotic centromeres.

Localization of neutralizing epitopes and the receptor-binding site within the amino-terminal 330 amino acids of the murine coronavirus spike protein.

Kubo, H; Yamada, Y K; Taguchi, F
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /09/1994 Português
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To localize the epitopes recognized by monoclonal antibodies (MAbs) specific for the S1 subunit of the murine coronavirus JHMV spike protein, we have expressed S1 proteins with different deletions from the C terminus of S1. S1utt is composed of the entire 769-amino-acid (aa) S1 protein; S1NM, S1N, S1n(330), and S1n(220) are deletion mutants with 594, 453, 330, and 220 aa from the N terminus of the S1 protein. The expressed S1 deletion mutant proteins were examined for reactivities to a panel of MAbs. All MAbs classified in groups A and B, those reactive to most mouse hepatitis virus (MHV) strains and those specific for isolate JHMV, respectively, recognized S1N(330) and the larger S1 deletion mutants but failed to react with S1N(220). MAbs in group C, specific for the larger S protein of JHMV, reacted only with the S1utt protein without any deletion. These results indicated that the domain composed of the N-terminal 330 aa comprised the cluster of conformational epitopes recognized by MAbs in groups A and B. It was also shown that the epitopes of MAbs in group C were not restricted to the region missing in the smaller S protein. These results together with the fact that all MAbs in group B retained high neutralizing activity suggested the possibility that the N-terminal 330 aa are responsible for binding to the MHV-specific receptors. In investigate this possibility...

Ribulose 1,5-bisphosphate carboxylase. Effect on the catalytic properties of changing methionine-330 to leucine in the Rhodospirillum rubrum enzyme.

Terzaghi, B E; Laing, W A; Christeller, J T; Petersen, G B; Hill, D F
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 01/05/1986 Português
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Oligonucleotide-directed mutagenesis of cloned Rhodospirillum rubrum ribulose bisphosphate carboxylase/oxygenase with a synthetic 13mer oligonucleotide primer was used to effect a change at Met-330 to Leu-330. The resultant enzyme was kinetically examined in some detail and the following changes were found. The Km(CO2) increased from 0.16 to 2.35 mM, the Km(ribulose bisphosphate) increased from 0.05 to 1.40 mM for the carboxylase reaction and by a similar amount for the oxygenase reaction. The Ki(O2) increased from 0.17 to 6.00 mM, but the ratio of carboxylase activity to oxygenase activity was scarcely affected by the change in amino acid. The binding of the transition state analogue 2-carboxyribitol 1,5-bisphosphate was reversible in the mutant and essentially irreversible in the wild type enzyme. Inhibition by fructose bisphosphate, competitive with ribulose bisphosphate, was slightly increased in the mutant enzyme. These data suggest that the change of the residue from methionine to leucine decreases the stability of the enediol reaction intermediate.

The fate of 2,4,6-tri-(3′,5′-di-tert.-butyl-4′- hydroxybenzyl)mesitylene (Ionox 330) in the dog and rat

Wright, A. S.; Crowne, R. S.; Hathway, D. E.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /04/1965 Português
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27.05%
1. Unchanged Ionox 330 is quantitatively eliminated in the faeces of dogs, rats and man after oral administration, and 14C is absent from the urine and expired gases of rats intubated with [14C]Ionox 330. Dogs and rats do not show a sex difference in this pattern of elimination. 2. Quantitative elimination of [14C]Ionox 330 and the absence of 14C in the carcass and viscera of rats 72hr. after dosage show that this substance does not accumulate in the body. 3. No metabolites are formed in consequence of the ingestion of Ionox 330. 4. Rats eliminate three-quarters or more of a dose (285·7mg./kg. body wt.) of Ionox 330 in 24hr. and the remainder during 24–48hr., and dogs eliminate the whole dose (90mg./kg. body wt.) within 48hr. and a variable proportion within 24hr. These rates of elimination are consistent with the passage of unabsorbed material through the alimentary canal. 5. After removal of the alimentary canal, radioactivity is absent from the carcass and remaining viscera of rats 8, 16 and 24hr. after ingestion of [14C]Ionox 330, and this strongly suggests the absence of alimentary absorption. 6. The absence of 14C in the 24hr. bile of animals with biliary fistulae establishes that [14C]Ionox 330 is not absorbed from the gastro-intestinal tract.

Analysis of Phosphorylation of Connexin43 at S325/328/330 in Normoxic and Ischemic Heart

Lampe, Paul D.; Cooper, Cynthia D.; King, Timothy J.; Burt, Janis M.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
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The functional consequences of Connexin43 (Cx43) phosphorylation remain largely unexplored. Using an antibody that specifically recognizes Cx43 phosphorylated at serines 325/328/330 (pS325/328/330), we show that this form of Cx43 as well as total Cx43 labeling was restricted to the intercalated disk region of normal ventricular tissue. In ischemic heart, significant relocalization of total Cx43 to the lateral edges of myocytes was evident; however pS325/328/330-Cx43 remained predominately at the intercalated disk. Western immunoblots indicated a 8-fold decrease in pS325/328/330-Cx43 in ischemic tissue. Peptide binding and competition experiments indicated that our antibody mainly detected Cx43 phosphorylated at S328 and/or S330 in heart tissue. To evaluate how this change in Cx43 phosphorylation might contribute to ischemia-induced downregulation of intercellular communication, we stably transfected Cx43−/− cells with Cx43-S325/328/330A (Cx43-TM). Cx43-TM was not efficiently processed to isoforms that have been correlated with gap junction assembly. Nevertheless, Cx43-TM cells were electrically coupled, although coupling developed over a slowed time course. Fully open channels were only rarely observed in the Cx43-TM cells, and Lucifer Yellow dye coupling was significantly reduced compared to wild-type. These data suggest that phosphorylation of Cx43 at serines 325...

The specificity of nephritogenic antibodies. V. Glomerular localization of anti-GP 330 and anti-GP 90 antibodies present in passive Heymann serum.

Bagchus, W. M.; Hoedemaeker, P. J.; Slegers, J. F.; Bakker, W. W.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /12/1988 Português
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Administration in the rat of rabbit antibodies directed against rat tubular brushborder antigens (FXIA) leads to membranous glomerulopathy (HICN) associated with glomerular immune complexes (ICXS). These anti-FXIA antibodies (Abs) contain two major specificities, anti-GP 330 and anti-GP 90. The contribution of each specificity to the localization of anti-FXIA Abs was studied by direct immunofluorescence. Perfusion studies, under conditions which avoid ischaemia, confirmed that in this system glomerular localization of anti-FXIA Abs depends only on anti-GP 90 Abs, and the failure of anti-GP 330 Abs to localize after perfusion could not be attributed to ischaemia. In contrast, intravenous (i.v.) injection of anti-GP 330 Abs results in granular deposits of rabbit IgG, similar to those observed using anti-FXIA Abs. Injection i.v. of anti-GP 90 Abs results only in (faint) linear deposits. Using alternating and combined perfusion studies with these Abs, it is shown that anti-GP 90 Abs do not influence localization of anti-GP 330 Abs. In addition, systemic administration of anti-GP 90 Abs combined with perfusion of anti-GP 330 Abs does not facilitate localization of anti-GP 330 Abs. Although directly after i.v. injection of anti-FXIA Abs some anti-GP 90 Abs probably localize in the glomerular capillary wall...

Conformational isomerization kinetics of pent-1-en-4-yne with 3,330 cm−1 of internal energy measured by dynamic rotational spectroscopy

Dian, Brian C.; Brown, Gordon G.; Douglass, Kevin O.; Rees, Frances S.; Johns, James E.; Nair, Pradeep; Suenram, Richard D.; Pate, Brooks H.
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
Português
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We demonstrate the application of molecular rotational spectroscopy to measure the conformation isomerization rate of vibrationally excited pent-1-en-4-yne (pentenyne). The rotational spectra of single quantum states of pentenyne are acquired by using a combination of IR–Fourier transform microwave double-resonance spectroscopy and high-resolution, single-photon IR spectroscopy. The quantum states probed in these experiments have energy eigenvalues of ≈3,330 cm−1 and lie above the barrier to conformational isomerization. At this energy, the presence of intramolecular vibrational energy redistribution (IVR) is indicated through the extensive local perturbations found in the high-resolution rotation–vibration spectrum of the acetylenic C–H stretch normal-mode fundamental. The fact that the IVR process produces isomerization is deduced through a qualitatively different appearance of the excited-state rotational spectra compared with the pure rotational spectra of pentenyne. The rotational spectra of the vibrationally excited molecular eigenstates display coalescence between the characteristic rotational frequencies of the stable cis and skew conformations of the molecule. This coalescence is observed for quantum states prepared from laser excitation originating in the ground vibrational state of either of the two stable conformers. Experimental isomerization rates are extracted by using a three-state Bloch model of the dynamic rotational spectra that includes the effects of chemical exchange between the stable conformations. The time scale for the conformational isomerization rate of pentenyne at total energy of 3...

Two microRNAs, miR-330 and miR-125b-5p, mark the juxtaglomerular cell and balance its smooth muscle phenotype

Medrano, Silvia; Monteagudo, Maria C.; Sequeira-Lopez, Maria Luisa S.; Pentz, Ellen S.; Gomez, R. Ariel
Fonte: American Physiological Society Publicador: American Physiological Society
Tipo: Artigo de Revista Científica
Português
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We have shown that microRNAs (miRNAs) are necessary for renin cell specification and kidney vascular development. Here, we used a screening strategy involving microarray and in silico analyses, along with in situ hybridization and in vitro functional assays to identify miRNAs important for renin cell identity. Microarray studies using vascular smooth muscle cells (SMCs) of the renin lineage and kidney cortex under normal conditions and after reacquisition of the renin phenotype revealed that of 599 miRNAs, 192 were expressed in SMCs and 234 in kidney cortex. In silico analysis showed that the highly conserved miR-330 and miR-125b-5p have potential binding sites in smoothelin (Smtn), calbindin 1, smooth muscle myosin heavy chain, α-smooth muscle actin, and renin genes important for the myoepithelioid phenotype of the renin cell. RT-PCR studies confirmed miR-330 and miR-125b-5p expression in kidney and SMCs. In situ hybridization revealed that under normal conditions, miR-125b-5p was expressed in arteriolar SMCs and in juxtaglomerular (JG) cells. Under conditions that induce reacquisition of the renin phenotype, miR-125b-5p was downregulated in arteriolar SMCs but remained expressed in JG cells. miR-330, normally absent, was expressed exclusively in JG cells of treated mice. In vitro functional studies showed that overexpression of miR-330 inhibited Smtn expression in SMCs. On the other hand...

MicroRNA-330 Is an Oncogenic Factor in Glioblastoma Cells by Regulating SH3GL2 Gene

Qu, Shengtao; Yao, Yilong; Shang, Chao; Xue, Yixue; Ma, Jun; Li, Zhen; Liu, Yunhui
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 21/09/2012 Português
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27.01%
MicroRNAs have recently emerged as key regulators of cancers. This study was therefore conducted to investigate the role of miR-330 in biological behaviors of human glioblastoma U87 and U251 cell lines and its molecular mechanism. SH3GL2 gene was identified as the target of miR-330. MiR-330 overexpression was established by transfecting miR-330 precursor into U87 and U251 cells, and its effects on proliferation, migration, invasion, cell cycle and apoptosis were studied. Overexpression of miR-330 can enhance cellular proliferation, promote migration and invasion, activate cell cycle and also inhibit apoptosis in U87 and U251 cells. Collectively, these above-mentioned results suggest that miRNA-330 plays an oncogenic role in human glioblastoma by regulating SH3GL2 gene and might be a new therapeutic target of human glioblastoma.

MiR-330-Mediated Regulation of SH3GL2 Expression Enhances Malignant Behaviors of Glioblastoma Stem Cells by Activating ERK and PI3K/AKT Signaling Pathways

Yao, Yilong; Xue, Yixue; Ma, Jun; Shang, Chao; Wang, Ping; Liu, Libo; Liu, Wenjing; Li, Zhen; Qu, Shengtao; Li, Zhiqing; Liu, Yunhui
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 15/04/2014 Português
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27.05%
MicroRNAs are currently considered as an active and rapidly evolving area for the treatment of tumors. In this study, we elucidated the biological significance of miR-330 in glioblastoma stem cells (GSCs) as well as the possible molecular mechanisms. SH3GL2 is mainly distributed in the central nervous system and considered to be a tumor suppressor in many tumors. In the present study, we identified miR-330 as a potential regulator of SH3GL2 and we found that it was to be inversely correlated with SH3GL2 expression in GSCs which were isolated from U87 cell lines. The expression of miR-330 enhanced cellular proliferation, promoted cell migration and invasion, and dampened cell apoptosis. When the GSCs were co-transfected with the plasmid containing short hairpin RNA directed against human SH3GL2 gene and miR-330 mimic, we found that miR-330 promoted the malignant behavior of GSCs by down-regulating the expression of SH3GL2. Meanwhile, the ERK and PI3K/AKT signaling pathways were significantly activated, leading to the decreased expression of apoptotic protein and increased expression of anti-apoptotic protein. Furthermore, in orthotopic mouse xenografts, the mice given stable over-expressed SH3GL2 cells co-transfected with miR-330 knockdown plasmid had the smallest tumor sizes and longest survival. In conclusion...

The Association of −330 Interleukin-2 Gene Polymorphism with Its Plasma Concentration in Iranian Multiple Sclerosis Patients

Sayad, Arezou; Movafagh, Abolfazl
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
Português
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26.81%
Multiple sclerosis (MS) is a chronic neuroinflammatory demyelinating disease of the central nervous system. The cytokine genes are involved in autoimmune diseases such as MS. In this study, we report the influence of −330 interleukin-2 (IL2) gene polymorphism on its plasma levels in a group of Iranian MS patients. In this study 100 MS patients and 100 ethnically, age, and sex matched healthy controls were selected from Medical Genetics Department of Sarem Women Hospital. Blood samples of all individuals were collected in EDTA tubes. The restriction fragment length polymorphism PCR (RFLP) method was applied to determine various alleles and genotypes in these individuals. Plasma concentration of IL2 was measured in all the samples using human IL2 kit. The frequency of −330 T/T IL2 genotype was higher in MS patients compared to normal individuals. Accordingly, the plasma levels of IL2 were significantly higher (P < 0.0001) in patients when compared to the control group. In conclusion, in case of MS patients the −330 T/T IL2 genotype is associated with higher plasma levels of IL2.

MicroRNA-330-3p functions as an oncogene in human esophageal cancer by targeting programmed cell death 4

Meng, Hui; Wang, Kai; Chen, Xuedan; Guan, Xingying; Hu, Liwen; Xiong, Gang; Li, Juan; Bai, Yun
Fonte: e-Century Publishing Corporation Publicador: e-Century Publishing Corporation
Tipo: Artigo de Revista Científica
Publicado em 15/02/2015 Português
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27.01%
MicroRNAs comprise a family of small non-coding RNA molecules that have emerged as key post-transcriptional regulators of gene expression. Aberrant miRNA expression has been linked to various human tumors. This study was aimed to identify novel miRNAs involved in the carcinogenesis of esophageal squamous cell carcinoma (ESCC) and their potential functions. We performed miRNA microarray and found that miR-330-3p was highly expressed in ESCC tumor tissues. qRT-PCR further confirmed the result in other 35 pairs of ESCC tumor tissues and ESCC cell lines. Ectopic expression of miR-330-3p significantly promoted ESCC cell proliferation, survival, migration, invasion in vitro and stimulated tumor formation in nude mice. Knockdown of miR-330-3p leaded to the opposite effects. The luciferase assay confirmed that miR-330-3p directly interacted with the PDCD4 mRNA 3’ un-translated region (UTR). Moreover, expression of PDCD4 was inversely associated with miR-330-3p in ESCC tissues. Silencing of PDCD4 significantly promoted cell growth, cell migration, invasion and inhibited cisplatin-induced apoptosis in ESCC cells. This study suggested that miR-330-3p might play an oncogenic role in the development of ESCC partially via suppression of PDCD4 expression.

The Broad Anti-AML Activity of the CD33/CD3 BiTE Antibody Construct, AMG 330, Is Impacted by Disease Stage and Risk

Harrington, Kimberly H.; Gudgeon, Chelsea J.; Laszlo, George S.; Newhall, Kathryn J.; Sinclair, Angus M.; Frankel, Stanley R.; Kischel, Roman; Chen, Guang; Walter, Roland B.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 25/08/2015 Português
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27.13%
The CD33/CD3-bispecific T-cell engaging (BiTE) antibody construct, AMG 330, potently lyses CD33+ leukemic cells in vitro. Using specimens from 41 patients with acute myeloid leukemia (AML), we studied the factors that might contribute to clinical response or resistance. For this purpose, thawed aliquots of primary AML samples were immunophenotypically characterized and subjected to various doses of AMG 330 in the presence or absence of healthy donor T-cells. After 48 hours, drug-specific cytotoxicity was quantified and correlated with CD33 expression levels, amounts of T-cells present, and other disease characteristics. AMG 330 caused modest cytotoxicity that was correlated with the amount of autologous T-cells (P = 0.0001) but not CD33 expression, as AMG 330 exerted marked cytotoxic effects in several specimens with minimal CD33 expression. With healthy donor T-cells added, AMG 330 cytotoxicity depended on the drug dose and effector:target (E:T) cell ratio. High cytotoxic activity was observed even with minimal CD33 expression, and AMG 330 cytotoxicity and CD33 expression correlated only at high E:T cell ratio and high AMG 330 doses (P<0.003). AMG 330 resulted in significantly higher cytotoxicity in specimens from patients with newly diagnosed AML than those with relapsed/refractory disease despite similar levels of CD33 on myeloblasts. AMG 330 cytotoxicity also appeared greater in specimens from patients with favorable-risk disease as compared to other specimens. Together...

T-cell ligands modulate the cytolytic activity of the CD33/CD3 BiTE antibody construct, AMG 330

Laszlo, G S; Gudgeon, C J; Harrington, K H; Walter, R B
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
Português
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26.96%
Preclinical and emerging clinical studies demonstrate that bispecific T-cell engaging (BiTE) antibody constructs can potently lyse targeted tumor cells, but the determinants for their activity remain incompletely understood. Using human acute myeloid leukemia (AML) cell lines engineered to overexpress individual T-cell ligands, we found that expression of the inhibitory ligands, PD-L1 and PD-L2, reduced the cytolytic activity of the BiTE antibody construct targeting CD33, AMG 330; conversely, expression of the activating ligands, CD80 and CD86, augmented the cytotoxic activity of AMG 330. Consistent with these findings, treatment with an activating antibody directed at the co-stimulatory T-cell receptor, CD28, significantly increased AMG 330-induced cytotoxicity in human AML cell lines. Using specimens from 12 patients with newly diagnosed or relapsed/refractory AML, we found that activation of CD28 also increased the activity of AMG 330 in primary human AML cells (P=0.023). Together, our findings indicate that T-cell ligands and co-receptors modulate the anti-tumor activity of the CD33/CD3 BiTE antibody construct, AMG 330. These findings suggest that such ligands/co-receptors could serve as biomarkers of response and that co-treatment strategies with pharmacological modulators of T-cell receptor signaling could be utilized to further enhance the activity of this targeted therapeutic.

The VLT-FLAMES Survey of Massive Stars: Observations centered on the Magellanic Cloud clusters NGC 330, NGC 346, NGC 2004, and the N11 region

Evans, C. J.; Lennon, D. J.; Smartt, S. J.; Trundle, C.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
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We present new observations of 470 stars using the Fibre Large Array Multi-Element Spectrograph (FLAMES) instrument in fields centered on the clusters NGC 330 and NGC 346 in the Small Magellanic Cloud (SMC), and NGC 2004 and the N11 region in the Large Magellanic Cloud (LMC). A further 14 stars were observed in the N11 and NGC 330 fields using the Ultraviolet and Visual Echelle Spectrograph (UVES) for a separate programme. Spectral classifications and stellar radial velocities are given for each target, with careful attention to checks for binarity. In particular we have investigated previously unexplored regions around the central LH9/LH10 complex of N11, finding ~25 new O-type stars from our spectroscopy. We have observed a relatively large number of Be-type stars that display permitted Fe II emission lines. These are primarily not in the cluster cores and appear to be associated with classical Be-type stars, rather than pre main-sequence objects. The presence of the Fe II emission, as compared to the equivalent width of H$\alpha$, is not obviously dependent on metallicity. We have also explored the relative fraction of Be- to normal B-type stars in the field-regions near to NGC 330 and NGC 2004, finding no strong evidence of a trend with metallicity when compared to Galactic results. A consequence of service observations is that we have reasonable time-sampling in three of our FLAMES fields. We find lower limits to the binary fraction of O- and early B-type stars of 23 to 36%. One of our targets (NGC346-013) is especially interesting with a massive...

Spectroscopy of Be stars in the Small Magellanic Cloud cluster NGC 330

Keller, Stefan C.; Bessell, Michael S.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 28/09/1998 Português
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The presence of an anomalously large population of Be stars in the young cluster NGC 330 in the SMC has been noted by Feast (1972), Bessell & Wood (1993), Grebel (1996) and most recently Keller et al. (1998). We present results from follow-up medium resolution spectra of the bright Be stars identified in Keller et al. (1998) and in the spectroscopic study of Mazzali et al. (1996). We find that the study of Mazzali et al. has overestimated the number of Be stars within NGC 330. Many of the bright B type stars identified by Mazzali et al. as Be stars show no signs of emission after correction for the diffuse HII emission pervading the cluster field. In the study of Mazzali et al. (1996) evidence is presented suggesting that all Be stars in NGC 330 have a common inclination of their rotation axes to the line of sight. For our sample of Be stars we present the emission equivalent widths and observed rotational velocities. An examination of these quantities shows that there is no evidence of a preferential alignment of the rotational axes, rather we are observing a population with random rotational axis alignment and disk size.; Comment: 10 pages, A+A accepted

The Low-Mass X-ray Binary X1822-330 in the Globular Cluster NGC 6652: A Serendipitous ASCA Observation

Mukai, Koji; Smale, Alan P.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 19/11/1999 Português
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26.81%
The Low Mass X-ray Binary (LMXB) X1822-330 in NGC 6652 is one of 12 bright, or transient, X-ray sources to have been discovered in Globular Clusters. We report on a serendipitous ASCA observation of this Globular Cluster LMXB, during which a Type I burst was detected and the persistent, non-burst emission of the source was at its brightest level recorded to date. No orbital modulation was detected, which argues against a high inclination for the X1822-330 system. The spectrum of the persistent emission can be fit with a power law plus a partial covering absorber, although other models are not ruled out. Our time-resolved spectral analysis through the burst shows, for the first time, clear evidence for spectral cooling from kT=2.4+/-0.6 keV to kT=1.0+/0.1 keV during the decay. The measured peak flux during the burst is ~10% of the Eddington luminosity for a 1.4 Msun neutron star. These are characteristic of a Type I burst, in the context of the relatively low quiescent luminosity of X1822-330.; Comment: 9 pages, 5 figures, accepted for ApJ

BeppoSAX study of the X-ray binary XB 1832-330 located in the globular cluster NGC 6652

Parmar, A. N.; Oosterbroek, T.; Sidoli, L.; Stella, L.; Frontera, F.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 22/10/2001 Português
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Results of a 2001 March 17-20 BeppoSAX observation of the X-ray binary XB 1832-330 located in the globular cluster NGC 6652 are presented. In contrast to the majority of luminous globular cluster X-ray sources, the (0.1-200 keV) BeppoSAX spectrum cannot be fit with a disk-blackbody and comptt Comptonization model, unless partial covering is included. This confirms the ASCA detection of partial covering by Mukai & Smale (2000). The best-fit spectral parameters are similar to those of the globular cluster sources with orbital periods of <1 hr, implying that XB 1832-330 is also an ultra-compact system. A plausible optical candidate to XB 1832-330 has recently been discovered by Heinke et al. (2001) which shows evidence for possible 0.92, 2.22, or 4.44 hr periodicities. We find no evidence for any 2-10 keV periodic modulation at any of these periods with a 2 sigma upper limit to the semi-amplitude of any sinusoid of < 1.5%.; Comment: 5 pages. To appear in A&A

Fast transition of type-B QPO in the black hole transient XTE J1817-330

Sriram, K.; Rao, A. R.; Choi, C. S.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 07/03/2012 Português
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The evolution of different types of quasi-periodic oscillations (QPOs) and the coupled radiative/physical changes in the accretion disk are still poorly understood. In a few black hole binaries it was found that fast evolution of QPOs is associated with spectral variations. Such studies in other black hole binaries are important to understand the QPO phenomenon. For the black hole transient XTE J1817-330, we study fast QPO transitions and accompanying spectral variations to investigate what causes the spectral variation during the QPO transition. Roy et al. (2011) found QPOs in ten RXTE observations of XTE J1817-330. We found that, among the ten observations, only one observation shows erratic dips in its X-ray light curve. The power density spectra and the corresponding energy spectra were extracted and analyzed for the dip and non-dip sections of the light curve. We found that type-B $\sim$6 Hz QPO changes into type-A QPO in a few tens of seconds along with a flux decrease. This transient evolution is accompanied with a significant spectral variation. We report a transient QPO feature and accompanying spectral variation in XTE J1817-330. Based on our findings, we discuss the origin of fast evolution of QPOs and spectral variations.; Comment: 8 pages...