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BONA FIDE, STRONG-VARIABLE GALACTIC LUMINOUS BLUE VARIABLE STARS ARE FAST ROTATORS: DETECTION OF A HIGH ROTATIONAL VELOCITY IN HR CARINAE

GROH, J. H.; DAMINELI, A.; HILLIER, D. J.; BARBA, R.; FERNANDEZ-LAJUS, E.; GAMEN, R. C.; MOISES, A. P.; SOLIVELLA, G.; TEODORO, M.
Fonte: IOP PUBLISHING LTD Publicador: IOP PUBLISHING LTD
Tipo: Artigo de Revista Científica
ENG
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25.88%
We report optical observations of the luminous blue variable (LBV) HR Carinae which show that the star has reached a visual minimum phase in 2009. More importantly, we detected absorptions due to Si lambda lambda 4088-4116. To match their observed line profiles from 2009 May, a high rotational velocity of nu(rot) similar or equal to 150 +/- 20 km s(-1) is needed (assuming an inclination angle of 30 degrees), implying that HR Car rotates at similar or equal to 0.88 +/- 0.2 of its critical velocity for breakup (nu(crit)). Our results suggest that fast rotation is typical in all strong-variable, bona fide galactic LBVs, which present S-Dor-type variability. Strong-variable LBVs are located in a well-defined region of the HR diagram during visual minimum (the ""LBV minimum instability strip""). We suggest this region corresponds to where nu(crit) is reached. To the left of this strip, a forbidden zone with nu(rot)/nu(crit) > 1 is present, explaining why no LBVs are detected in this zone. Since dormant/ex LBVs like P Cygni and HD 168625 have low nu(rot), we propose that LBVs can be separated into two groups: fast-rotating, strong-variable stars showing S-Dor cycles (such as AG Car and HR Car) and slow-rotating stars with much less variability (such as P Cygni and HD 168625). We speculate that supernova (SN) progenitors which had S-Dor cycles before exploding (such as in SN 2001ig...

Cis- and trans-splicing of mRNAs mediated by tRNA sequences in eukaryotic cells

Di Segni, Gianfranco; Gastaldi, Serena; Tocchini-Valentini, Glauco P.
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
EN
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The formation of chimeric mRNAs is a strategy used by human cells to increase the complexity of their proteome, as revealed by the ENCODE project. Here, we use Saccharomyces cerevisiae to show a way by which trans-spliced mRNAs can be generated. We demonstrate that a pretRNA inserted into a premRNA context directs the splicing reaction precisely to the sites of the tRNA intron. A suppressor pretRNA gene was inserted, in cis, into the sequence encoding the third cytoplasmic loop of the Ste2 or Ste3 G protein-coupled receptor. The hybrid RNAs are spliced at the specific pretRNA splicing sites, releasing both functional tRNAs that suppress nonsense mutations and translatable mRNAs that activate the signal transduction pathway. The RNA molecules extracted from yeast cells were amplified by RT-PCR, and their sequences were determined, confirming the identity of the splice junctions. We then constructed two fusions between the premRNA sequence (STE2 or STE3) and the 5′- or 3′-pretRNA half, so that the two hybrid RNAs can associate with each other, in trans, through their tRNA halves. Splicing occurs at the predicted pretRNA sites, producing a chimeric STE3-STE2 receptor mRNA. RNA trans-splicing mediated by tRNA sequences, therefore, is a mechanism capable of producing new kinds of RNAs...

Somatic Point Mutations in mtDNA Control Region Are Influenced by Genetic Background and Associated with Healthy Aging: A GEHA Study

Rose, Giuseppina; Romeo, Giuseppe; Dato, Serena; Crocco, Paolina; Bruni, Amalia C.; Hervonen, Antti; Majamaa, Kari; Sevini, Federica; Franceschi, Claudio; Passarino, Giuseppe;
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 14/10/2010 EN
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Tissue specific somatic mutations occurring in the mtDNA control region have been proposed to provide a survival advantage. Data on twins and on relatives of long-lived subjects suggested that the occurrence/accumulation of these mutations may be genetically influenced. To further investigate control region somatic heteroplasmy in the elderly, we analyzed the segment surrounding the nt 150 position (previously reported as specific of Leukocytes) in various types of leukocytes obtained from 195 ultra-nonagenarians sib-pairs of Italian or Finnish origin collected in the frame of the GEHA Project. We found a significant correlation of the mtDNA control region heteroplasmy between sibs, confirming a genetic influence on this phenomenon. Furthermore, many subjects showed heteroplasmy due to mutations different from the C150T transition. In these cases heteroplasmy was correlated within sibpairs in Finnish and northern Italian samples, but not in southern Italians. This suggested that the genetic contribution to control region mutations may be population specific. Finally, we observed a possible correlation between heteroplasmy and Hand Grip strength, one of the best markers of physical performance and of mortality risk in the elderly. Our study provides new evidence on the relevance of mtDNA somatic mutations in aging and longevity and confirms that the occurrence of specific point mutations in the mtDNA control region may represent a strategy for the age-related remodelling of organismal functions.

Targeting Social and Economic Correlates of Cancer Treatment Appointment Keeping among Immigrant Chinese Patients

Gany, Francesca; Ramirez, Julia; Chen, Serena; Leng, Jennifer C. F.
Fonte: Springer US Publicador: Springer US
Tipo: Artigo de Revista Científica
EN
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Chinese immigrants have high rates of a variety of cancers and face numerous social and economic barriers to cancer treatment appointment keeping. This study is a nested cohort of 82 Chinese patients participating in the Immigrant Cancer Portal Project. Twenty-two percent reported having missed appointments for oncology follow-up, radiation therapy, and/or chemotherapy. Patients most commonly reported needing assistance with financial support to enable appointment keeping. Efforts to further address social and economic correlates in cancer care should be developed for this population.

Fine Mapping of Five Loci Associated with Low-Density Lipoprotein Cholesterol Detects Variants That Double the Explained Heritability

Sanna, Serena; Li, Bingshan; Mulas, Antonella; Sidore, Carlo; Kang, Hyun M.; Jackson, Anne U.; Piras, Maria Grazia; Usala, Gianluca; Maninchedda, Giuseppe; Sassu, Alessandro; Serra, Fabrizio; Palmas, Maria Antonietta; Wood, William H.; Njølstad, Inger; L
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
EN
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Complex trait genome-wide association studies (GWAS) provide an efficient strategy for evaluating large numbers of common variants in large numbers of individuals and for identifying trait-associated variants. Nevertheless, GWAS often leave much of the trait heritability unexplained. We hypothesized that some of this unexplained heritability might be due to common and rare variants that reside in GWAS identified loci but lack appropriate proxies in modern genotyping arrays. To assess this hypothesis, we re-examined 7 genes (APOE, APOC1, APOC2, SORT1, LDLR, APOB, and PCSK9) in 5 loci associated with low-density lipoprotein cholesterol (LDL-C) in multiple GWAS. For each gene, we first catalogued genetic variation by re-sequencing 256 Sardinian individuals with extreme LDL-C values. Next, we genotyped variants identified by us and by the 1000 Genomes Project (totaling 3,277 SNPs) in 5,524 volunteers. We found that in one locus (PCSK9) the GWAS signal could be explained by a previously described low-frequency variant and that in three loci (PCSK9, APOE, and LDLR) there were additional variants independently associated with LDL-C, including a novel and rare LDLR variant that seems specific to Sardinians. Overall, this more detailed assessment of SNP variation in these loci increased estimates of the heritability of LDL-C accounted for by these genes from 3.1% to 6.5%. All association signals and the heritability estimates were successfully confirmed in a sample of ∼10...

Genotype calling and haplotyping in parent-offspring trios

Chen, Wei; Li, Bingshan; Zeng, Zhen; Sanna, Serena; Sidore, Carlo; Busonero, Fabio; Kang, Hyun Min; Li, Yun; Abecasis, Gonçalo R.
Fonte: Cold Spring Harbor Laboratory Press Publicador: Cold Spring Harbor Laboratory Press
Tipo: Artigo de Revista Científica
Publicado em /01/2013 EN
Relevância na Pesquisa
25.88%
Emerging sequencing technologies allow common and rare variants to be systematically assayed across the human genome in many individuals. In order to improve variant detection and genotype calling, raw sequence data are typically examined across many individuals. Here, we describe a method for genotype calling in settings where sequence data are available for unrelated individuals and parent-offspring trios and show that modeling trio information can greatly increase the accuracy of inferred genotypes and haplotypes, especially on low to modest depth sequencing data. Our method considers both linkage disequilibrium (LD) patterns and the constraints imposed by family structure when assigning individual genotypes and haplotypes. Using simulations, we show that trios provide higher genotype calling accuracy across the frequency spectrum, both overall and at hard-to-call heterozygous sites. In addition, trios provide greatly improved phasing accuracy—improving the accuracy of downstream analyses (such as genotype imputation) that rely on phased haplotypes. To further evaluate our approach, we analyzed data on the first 508 individuals sequenced by the SardiNIA sequencing project. Our results show that our method reduces the genotyping error rate by 50% compared with analysis using existing methods that ignore family structure. We anticipate our method will facilitate genotype calling and haplotype inference for many ongoing sequencing projects.

SHAVE: shrinkage estimator measured for multiple visits increases power in GWAS of quantitative traits

Meirelles, Osorio D; Ding, Jun; Tanaka, Toshiko; Sanna, Serena; Yang, Hsih-Te; Dudekula, Dawood B; Cucca, Francesco; Ferrucci, Luigi; Abecasis, Goncalo; Schlessinger, David
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
EN
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Measurement error and biological variability generate distortions in quantitative phenotypic data. In longitudinal studies with repeated measurements, the multiple measurements provide a route to reduce noise and correspondingly increase the strength of signals in genome-wide association studies (GWAS).To optimize noise correction, we have developed Shrunken Average (SHAVE), an approach using a Bayesian Shrinkage estimator. This estimator uses regression toward the mean for every individual as a function of (1) their average across visits; (2) their number of visits; and (3) the correlation between visits. Computer simulations support an increase in power, with results very similar to those expected by the assumptions of the model. The method was applied to a real data set for 14 anthropomorphic traits in ∼6000 individuals enrolled in the SardiNIA project, with up to three visits (measurements) for each participant. Results show that additional measurements have a large impact on the strength of GWAS signals, especially when participants have different number of visits, with SHAVE showing a clear increase in power relative to single visits. In addition, we have derived a relation to assess the improvement in power as a function of number of visits and correlation between visits. It can also be applied in the optimization of experimental designs or usage of measuring devices. SHAVE is fast and easy to run...

Informing Women on Menopause and Hormone Therapy: Know the Menopause a Multidisciplinary Project Involving Local Healthcare System

Donati, Serena; Satolli, Roberto; Colombo, Cinzia; Senatore, Sabrina; Cotichini, Rodolfo; Da Cas, Roberto; Spila Alegiani, Stefania; Mosconi, Paola
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 31/12/2013 EN
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The hidden genomic landscape of acute myeloid leukemia: subclonal structure revealed by undetected mutations

Bodini, Margherita; Ronchini, Chiara; Giacò, Luciano; Russo, Anna; Melloni, Giorgio E. M.; Luzi, Lucilla; Sardella, Domenico; Volorio, Sara; Hasan, Syed K.; Ottone, Tiziana; Lavorgna, Serena; Lo-Coco, Francesco; Candoni, Anna; Fanin, Renato; Toffoletti,
Fonte: American Society of Hematology Publicador: American Society of Hematology
Tipo: Artigo de Revista Científica
Publicado em 22/01/2015 EN
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The analyses carried out using 2 different bioinformatics pipelines (SomaticSniper and MuTect) on the same set of genomic data from 133 acute myeloid leukemia (AML) patients, sequenced inside the Cancer Genome Atlas project, gave discrepant results. We subsequently tested these 2 variant-calling pipelines on 20 leukemia samples from our series (19 primary AMLs and 1 secondary AML). By validating many of the predicted somatic variants (variant allele frequencies ranging from 100% to 5%), we observed significantly different calling efficiencies. In particular, despite relatively high specificity, sensitivity was poor in both pipelines resulting in a high rate of false negatives. Our findings raise the possibility that landscapes of AML genomes might be more complex than previously reported and characterized by the presence of hundreds of genes mutated at low variant allele frequency, suggesting that the application of genome sequencing to the clinic requires a careful and critical evaluation. We think that improvements in technology and workflow standardization, through the generation of clear experimental and bioinformatics guidelines, are fundamental to translate the use of next-generation sequencing from research to the clinic and to transform genomic information into better diagnosis and outcomes for the patient.

The Effect of viticultural climate on red and white wine typicity: characterization in Ibero-American grape-growing regions.

TONIETTO, J.; SOTES RUIZ, V.; ZANUS, M. C.; MONTES, C.; ULIARTE, E. M.; BRUNO, L. A.; CLIMACO, P.; PENA, A.; GUERRA, C. C.; CATANIA, C. D.; KOHLBERG, E. J.; PEREIRA, G. E.; RICARDO-DA-SILVA, J.-M.; RAGOUT, J. V.; NAVARRO, L. V.; LAUREANO, O.; CASTRO, R. d
Fonte: Journal International des Sciences de la Vigne et du Vin, Bordeaux, p. 19-23, 2014. Publicador: Journal International des Sciences de la Vigne et du Vin, Bordeaux, p. 19-23, 2014.
Tipo: Artigo em periódico indexado (ALICE)
EN
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This study is part of a CYTED (Ibero-American Program for Science, Technology and Development) project on vitivinicultural zoning. The objective was to characterize the effect of viticultural climate on red and white wine typicity in the macro Ibero-American viticultural region.; 2014; Spécial Laccave.

The INDEX-PM project: Health risks of indoor particulate matter

ARVANITIS Athanasios; KOTZIAS Dimitrios; KEPHALOPOULOS Stylianos; CARRER Paolo; CAVALLO Domenico; CESARONI G.; DE BROUWERE K; OLIVEIRA FERNANDES Eduardo; FORASTIERE F; FOSSATI Serena; FROMME H; HAVERINEN-SHAUGHNESSY U; JANTUNEN Matti; KATSOUYANNI K; KETTR
Fonte: PARLAR SCIENTIFIC PUBLICATIONS (P S P) Publicador: PARLAR SCIENTIFIC PUBLICATIONS (P S P)
Tipo: Articles in Journals Formato: Printed
ENG
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This article illustrates the methods and findings of assessing the health risks of exposure to indoor particulate matter in the frame of the European INDEX-PM project. The evaluation was performed by taking into account all sources and types of indoor particulate matter, and distinguishing it to PM from outdoor origin, from indoor combustion, environmental tobacco smoke, indoor air particles of biological origin, indoor resuspended mineral dust particles, semivolatile organic compounds, as well as secondary particles generated by indoor air chemistry. It comprises an outline of a state-ofthe- art review of existing exposure and dose-response data of indoor PM and focuses at deriving general and by-source risk characterisation and risk management options for reducing health effects associated to exposure to indoor PM.; JRC.I.1-Chemical Assessment and Testing

A land cover map of Latin America and the Caribbean in the framework of the SERENA project

Blanco P.D.; Colditz R.R.; Lopez Saldana G.; Hardtke L.A.; Llamas R.M.; Mari N.A.; Fischer A.; Caride C.; Acenolaza P.G.; del Valle H.F.; Lillo-Saavedra M.; Coronato F.; Opazo S.A.; Morelli F.; Anaya J.A.; Sione W.F.; Zamboni P.; Arroyo V.B.
Fonte: Universidade de Medellín Publicador: Universidade de Medellín
Tipo: Article; info:eu-repo/semantics/article
ENG
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56.63%
Land cover maps at different resolutions and mapping extents contribute to modeling and support decision making processes. Because land cover affects and is affected by climate change, it is listed among the 13 terrestrial essential climate variables. This paper describes the generation of a land cover map for Latin America and the Caribbean (LAC) for the year 2008. It was developed in the framework of the project Latin American Network for Monitoring and Studying of Natural Resources (SERENA), which has been developed within the GOFC-GOLD Latin American network of remote sensing and forest fires (RedLaTIF). The SERENA land cover map for LAC integrates: 1) the local expertise of SERENA network members to generate the training and validation data, 2) a methodology for land cover mapping based on decision trees using MODIS time series, and 3) class membership estimates to account for pixel heterogeneity issues. The discrete SERENA land cover product, derived from class memberships, yields an overall accuracy of 84% and includes an additional layer representing the estimated per-pixel confidence. The study demonstrates in detail the use of class memberships to better estimate the area of scarce classes with a scattered spatial distribution. The land cover map is already available as a printed wall map and will be released in digital format in the near future. The SERENA land cover map was produced with a legend and classification strategy similar to that used by the North American Land Change Monitoring System (NALCMS) to generate a land cover map of the North American continent...

The Effect of Viticultural Climate on Red and White Wine Typicity - Characterization in Ibero-American grape-growing regions

TONIETTO, J.; SOTES RUIZ, V.; ZANUS, M. C.; MONTES, C.; ULIARTE, E. M.; BRUNO, L. A.; CLIMACO, P.; PENA, A.; GUERRA, C. C.; CATANIA, C. D.; KOHLBERG, E. K.; PEREIRA, G. E.; RICARDO-DA-SILVA, J.-M.; RAGOUT, J. V.; NAVARRO, L. V.; LAUREANO, O.; DE CASTRO, R
Fonte: Spécial Laccave, J. Int. Sci. Vigne Vin, p. 19 - 23, 2014. Publicador: Spécial Laccave, J. Int. Sci. Vigne Vin, p. 19 - 23, 2014.
Tipo: Artigo em periódico indexado (ALICE)
EN
Relevância na Pesquisa
26%
Aim: This study is part of a CYTED (Ibero-American Program for Science, Technology and Development) project on vitivinicultural zoning. The objective was to characterize the effect of viticultural climate on red and white wine typicity in the macro Ibero-American viticultural region. Methods and results: The climate of 46 grape-growing regions in 6 Ibero-American countries (Argentina, Bolivia, Brazil, Chile, Spain and Portugal) was characterized using the three viticultural climate index of the Geoviticulture MCC System: the Heliothermal index HI, the Cool Night index CI and the Dryness index DI. The main sensory characteristics frequently observed in representative red and white wines of each of these regions were described by enology experts in the respective countries: intensity of colour, aroma, aroma-ripe fruit, body-palate concentration, alcohol, tannins (for red wines) and acidity as well as persistence on the palate. The data were submitted to a correlation analysis of the variables and Principal Component Analysis (PCA). Conclusion: The typicity of red and white wines was correlated with the HI, CI and DI viticultural climate indexes from the MCC System. The main wine sensory variables affected by viticultural climate were identified. Significance and impact of the study : The results can be used to project the potential impacts of climate change on wine sensory characteristics.; 2014

Challenges in recruiting subjects to a pilot trial of patient-managed in-hospital insulin

Acton, Emily K.; Leonard, Charles E.; Schutta, Mark H.; Cardillo, Serena; Troxel, Andrea B.; Trotta, Rebecca; Hennessy, Sean
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
Publicado em 01/10/2015 EN
Relevância na Pesquisa
25.88%

Intervention Mapping to Adapt Evidence-Based Interventions for Use in Practice: Increasing Mammography among African American Women

Highfield, Linda; Hartman, Marieke A.; Mullen, Patricia Dolan; Rodriguez, Serena A.; Fernandez, Maria E.; Bartholomew, L. Kay
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
EN
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25.88%
This paper describes and demonstrates the use of the systematic planning process, Intervention Mapping, to adapt an evidence-based public health intervention (EBI). We used a simplified version of Intervention Mapping (IM Adapt) to increase an intervention's fit with a new setting and population. IM Adapt guides researchers and practitioners in selecting an EBI, making decisions about whether and what to adapt, and executing the adaptation while guarding the EBI's essential elements (those responsible for effectiveness). We present a case study of a project in which we used IM Adapt to find, adapt, implement, and evaluate an EBI to improve mammography adherence for African American women in a new practice setting in Houston, Texas. IM Adapt includes the following (1) assess needs and organizational capacity; (2) find EBIs; (3) plan adaptations based on fit assessments; (4) make adaptations; (5) plan for implementation; and (6) plan for evaluation of the adapted EBI. The case study shows an example of how public health researchers and practitioners can use the tool to make it easier to find and use EBIs, thus encouraging greater uptake. IM Adapt adds to existing dissemination and adaptation models by providing detailed guidance on how to decide on effective adaptation...

The Formation and Evolution of Planetary Systems: Placing Our Solar System in Context with Spitzer

Meyer, Michael R.; Hillenbrand, Lynne A.; Backman, Dana; Beckwith, Steve; Bouwman, Jeroen; Brooke, Tim; Carpenter, John; Cohen, Martin; Cortes, Stephanie; Crockett, Nathan; Gorti, Uma; Henning, Thomas; Hines, Dean; Hollenbach, David; Kim, Jinyoung Serena;
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 03/01/2007
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25.88%
We provide an overview of the Spitzer Legacy Program ``Formation and Evolution of Planetary Systems" (FEPS) which was proposed in 2000, begun in 2001, and executed aboard the Spitzer Space Telescope between 2003 and 2006. This program exploits the sensitivity of Spitzer to carry out mid-infrared spectrophotometric observations of solar-type stars. With a sample of ~ 328 stars ranging in age from ~ 3 Myr to ~ 3 Gyr, we trace the evolution of circumstellar gas and dust from primordial planet-building stages in young circumstellar disks through to older collisionally generated debris disks. When completed, our program will help define the time scales over which terrestrial and gas giant planets are built, constrain the frequency of planetesimal collisions as a function of time, and establish the diversity of mature planetary architectures. In addition to the observational program, we have coordinated a concomitant theoretical effort aimed at understanding the dynamics of circumstellar dust with and without the effects of embedded planets, dust spectral energy distributions, and atomic and molecular gas line emission. Together with the observations, these efforts will provide astronomical context for understanding whether our Solar System - and its habitable planet - is a common or a rare circumstance. Additional information about the FEPS project can be found on the team website: feps.as.arizona.edu; Comment: To appear in the PASP...

The EXOTIME project: a status report on PG 1325+101 (QQ Vir)

Benatti, Serena; Silvotti, Roberto; Claudi, Riccardo U.; Schuh, Sonja; Lutz, Ronny; Kim, Seung-Lee; Janulis, Rimvydas; Paparò, Margit; Baran, Andrzej; Østensen, Roy
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 03/12/2010
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36.1%
After the discovery of V391 Peg b, the first planet detected around a post Red Giant phase star (Silvotti et al. 2007), the EXOTIME (EXOplanet search with the TIming MEthod) project is focused on the search for new planets with similar characteristics. The aim of the project is to organize a global observing network to collect as much data as possible for a sample of five subdwarf B (sdB) stars and share them in order to obtain a more precise analysis. These evolved pulsators may have extremely regular oscillation periods. This feature makes these stars suitable to search for planetary companions with the timing method as in the case of pulsars. In this contribution we present the project and some preliminary results for the star PG 1325+101 (QQ Vir) after the first two years of activity.; Comment: Proceedings of the 4th HELAS Conference (Lanzarote, 1-5 Feb. 2010), Astron. Nachrichten, in press

Metal-line emission from the warm-hot intergalactic medium: I. Soft X-rays

Bertone, Serena; Schaye, Joop; Vecchia, Claudio Dalla; Booth, C. M.; Theuns, Tom; Wiersma, Robert P. C.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
25.88%
Emission lines from metals offer one of the most promising ways to detect the elusive warm-hot intergalactic medium (WHIM; 10^5 K10^6 K). We find that the OVIII 18.97A is the strongest emission line, with a predicted maximum surface brightness of ~10^2 photon/s/cm^2/sr, but a number of other lines are only slightly weaker. All lines show a strong correlation between the intensity of the observed flux and the density and metallicity of the gas responsible for the emission. On the other hand, the potentially detectable emission consistently corresponds to the temperature at which the emissivity of the electronic transition peaks. The emission traces neither the baryonic nor the metal mass. In particular...

Metal-line emission from the warm-hot intergalactic medium: II. Ultraviolet

Bertone, Serena; Schaye, Joop; Booth, C. M.; Vecchia, Claudio Dalla; Theuns, Tom; Wiersma, Robert P. C.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
25.88%
Approximately half the baryons in the local Universe are thought to reside in the warm-hot intergalactic medium (WHIM). Emission lines from metals in the UV band are excellent tracers of the cooler fraction of this gas. We present predictions for the surface brightness of a sample of UV lines that could potentially be observed by the next generation of UV telescopes at z<1. We use a subset of simulations from the OWLS project to create emission maps and to investigate the effect of varying the physical prescriptions for star formation, supernova and AGN feedback, chemodynamics and radiative cooling. Most models produce results in agreement within a factor of a few, indicating that the predictions are robust. Of the lines we consider, C III is the strongest line, but it typically traces gas colder than 10^5 K. The same is true for Si IV. The second strongest line, C IV, traces circum-galactic gas with T~10^5 K. O VI and Ne VIII probe the warmer (T~10^5.5 K and T~10^6 K, respectively) and more diffuse gas that may be a better tracer of the large scale structure. N V emission is intermediate between C IV and O VI. The intensity of all emission lines increases strongly with gas density and metallicity, and for the bright emission it is tightly correlated with the temperature for which the line emissivity is highest. In particular...

Métodos de prospección arqueológica intensiva en el marco de un proyecto regional: el caso de la comarca de La Serena (Badajoz); Intensive survey methods in the framework of a regional project: the Serena Region study case

Mayoral Herrera, Victorino; Cerrillo Cuenca, E.; Celestino Pérez, S.
Fonte: Consejo Superior de Investigaciones Científicas (España) Publicador: Consejo Superior de Investigaciones Científicas (España)
Tipo: Artículo Formato: 2531331 bytes; application/pdf
SPA
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19 páginas, 10 figuras, 4 láminas.; [ES] El propósito de este trabajo es mostrar la metodología de prospección de superficie empleada en el marco de un proyecto regional sobre la evolución del paisaje en la comarca de La Serena (Badajoz). Se parte de una utilización crítica del concepto de sitio arqueológico y de una valoración del significado de estrategias intensivas de prospección de superficie en el contexto del estudio de la estructuración de los paisajes agrarios preindustriales. Se exponen los planteamientos, diseño y ejecución de los últimos trabajos efectuados. En una primera etapa se realiza una estimación global de la densidad de ítems y se determinan los posibles puntos de interés. Posteriormente se caracterizan cualitativamente las dispersiones detectadas mediante un muestreo aleatorio estratificado. Se pretende de este modo desterrar procedimientos selectivos y poco sistemáticos en la recogida de materiales de superficie, que conducen a notables sesgos en la información. Se destaca el balance alcanzado entre el tiempo y trabajo invertido y la resolución de información obtenida. La puesta en marcha de este método ha revelado su eficacia para caracterizar entidades arqueológicas que frecuentemente no se consideran en los análisis de tipo regional. Se discuten otros factores que interfieren en el reconocimiento de las dispersiones...