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  • 1
    In: Astronomy & Astrophysics, EDP Sciences, Vol. 675 ( 2023-07), p. A78-
    Abstract: We analyse cold-gas distributions in Virgo cluster galaxies using resolved observations of CO(2-1), which traces molecular hydrogen (H 2 ), and H  I from the Virgo Environment Traced In CO (VERTICO) and VLA Imaging of Virgo in Atomic Gas (VIVA) surveys. From a theoretical perspective, it is expected that environmental processes in clusters will have a stronger influence on diffuse atomic gas compared to the relatively dense molecular gas component, and that these environmental perturbations can compress the cold interstellar medium in cluster galaxies, leading to elevated star formation. In this work we observationally test these predictions for star-forming satellite galaxies within the Virgo cluster. We divided our Virgo galaxy sample into H  I -normal, H  I -tailed, and H  I -truncated classes and show, unsurprisingly, that the H  I -tailed galaxies have the largest quantitative H  I asymmetries. We also compared Virgo galaxies to a control sample of non-cluster galaxies and find that the former, on average, have H  I asymmetries that are 40 ± 10% larger than the latter. There is less separation between control, H  I -normal, H  I -tailed, and H  I -truncated galaxies in terms of H 2 asymmetries, and on average, Virgo galaxies have H 2 asymmetries that are only marginally (20 ± 10%) larger than the control sample. We find a weak correlation between H  I and H 2 asymmetries over our entire sample, but a stronger correlation for the galaxies that are strongly impacted by environmental perturbations. Finally, we divided the discs of the H  I -tailed Virgo galaxies into a leading half and trailing half according to the observed tail direction. We find evidence for excess molecular gas mass on the leading halves of the disc. This excess molecular gas is accompanied by an excess in the star formation rate such that the depletion time is, on average, unchanged.
    Type of Medium: Online Resource
    ISSN: 0004-6361 , 1432-0746
    RVK:
    RVK:
    Language: English
    Publisher: EDP Sciences
    Publication Date: 2023
    detail.hit.zdb_id: 1458466-9
    SSG: 16,12
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  • 2
    In: Astronomy & Astrophysics, EDP Sciences, Vol. 634 ( 2020-02), p. A121-
    Abstract: Context. Cloud-scale surveys of molecular gas reveal the link between giant molecular cloud properties and star formation across a range of galactic environments. Cloud populations in galaxy disks are considered to be representative of the normal star formation process, while galaxy centers tend to harbor denser gas that exhibits more extreme star formation. At high resolution, however, molecular clouds with exceptional gas properties and star formation activity may also be observed in normal disk environments. In this paper we study the brightest cloud traced in CO(2–1) emission in the disk of nearby spiral galaxy NGC 628. Aims. We characterize the properties of the molecular and ionized gas that is spatially coincident with an extremely bright H  II region in the context of the NGC 628 galactic environment. We investigate how feedback and large-scale processes influence the properties of the molecular gas in this region. Methods. High-resolution ALMA observations of CO(2–1) and CO(1−0) emission were used to characterize the mass and dynamical state of the “headlight” molecular cloud. The characteristics of this cloud are compared to the typical properties of molecular clouds in NGC 628. A simple large velocity gradient (LVG) analysis incorporating additional ALMA observations of 13 CO(1−0), HCO + (1−0), and HCN(1−0) emission was used to constrain the beam-diluted density and temperature of the molecular gas. We analyzed the MUSE spectrum using Starburst99 to characterize the young stellar population associated with the H  II region. Results. The unusually bright headlight cloud is massive (1 − 2 × 10 7   M ⊙ ), with a beam-diluted density of n H 2  = 5 × 10 4 cm −3 based on LVG modeling. It has a low virial parameter, suggesting that the CO emission associated with this cloud may be overluminous due to heating by the H  II region. A young (2 − 4 Myr) stellar population with mass 3 × 10 5   M ⊙ is associated. Conclusions. We argue that the headlight cloud is currently being destroyed by feedback from young massive stars. Due to the large mass of the cloud, this phase of the its evolution is long enough for the impact of feedback on the excitation of the gas to be observed. The high mass of the headlight cloud may be related to its location at a spiral co-rotation radius, where gas experiences reduced galactic shear compared to other regions of the disk and receives a sustained inflow of gas that can promote the mass growth of the cloud.
    Type of Medium: Online Resource
    ISSN: 0004-6361 , 1432-0746
    RVK:
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    Language: English
    Publisher: EDP Sciences
    Publication Date: 2020
    detail.hit.zdb_id: 1458466-9
    SSG: 16,12
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  • 3
    In: The Astrophysical Journal, American Astronomical Society, Vol. 892, No. 2 ( 2020-04-07), p. 148-
    Type of Medium: Online Resource
    ISSN: 1538-4357
    Language: Unknown
    Publisher: American Astronomical Society
    Publication Date: 2020
    detail.hit.zdb_id: 2207648-7
    detail.hit.zdb_id: 1473835-1
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  • 4
    In: The Astrophysical Journal, American Astronomical Society, Vol. 940, No. 2 ( 2022-12-01), p. 176-
    Abstract: We measure the molecular-to-atomic gas ratio, R mol , and the star formation rate (SFR) per unit molecular gas mass, SFE mol , in 38 nearby galaxies selected from the Virgo Environment Traced in CO (VERTICO) survey. We stack ALMA 12 CO ( J = 2−1) spectra coherently using H i velocities from the VIVA survey to detect faint CO emission out to galactocentric radii r gal ∼ 1.2 r 25 . We determine the scale lengths for the molecular and stellar components, finding a ∼3:5 relation compared to ∼1:1 in field galaxies, indicating that the CO emission is more centrally concentrated than the stars. We compute R mol as a function of different physical quantities. While the spatially resolved R mol on average decreases with increasing radius, we find that the mean molecular-to-atomic gas ratio within the stellar effective radius R e , R mol ( r 〈 R e ), shows a systematic increase with the level of H i , truncation and/or asymmetry (H I perturbation). Analysis of the molecular- and the atomic-to-stellar mass ratios within R e , R ⋆ mol ( r 〈 R e ) and R ⋆ atom ( r 〈 R e ) , shows that VERTICO galaxies have increasingly lower R ⋆ atom ( r 〈 R e ) for larger levels of H I perturbation (compared to field galaxies matched in stellar mass), but no significant change in R ⋆ m o l ( r 〈 R e ) . We also measure a clear systematic decrease of the SFE mol within R e , SFE mol ( r 〈 R e ), with increasingly perturbed H i . Therefore, compared to field galaxies from the field, VERTICO galaxies are more compact in CO emission in relation to their stellar distribution, but increasingly perturbed atomic gas increases their R mol and decreases the efficiency with which their molecular gas forms stars.
    Type of Medium: Online Resource
    ISSN: 0004-637X , 1538-4357
    RVK:
    Language: Unknown
    Publisher: American Astronomical Society
    Publication Date: 2022
    detail.hit.zdb_id: 2207648-7
    detail.hit.zdb_id: 1473835-1
    SSG: 16,12
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  • 5
    Online Resource
    Online Resource
    EDP Sciences ; 2022
    In:  EPJ Web of Conferences Vol. 265 ( 2022), p. 00007-
    In: EPJ Web of Conferences, EDP Sciences, Vol. 265 ( 2022), p. 00007-
    Abstract: This work presents an overview of the main results from the EMIR Multi-Line Probe of the ISM Regulating Galaxy Evolution (EMPIRE) survey, an IRAM-30m Large Program (∼ 500 h) which observed tracers of high density molecular gas across the disks of nine nearby, star-forming galaxies. EMPIRE is the first comprehensive and systematic study mapping high-density tracers including HCN, HCO + and HNC, as well as optically thin J = 1−0 transitions of 13 CO and C 18 O. Such a combination of spectroscopic tracers offers the best way to study cold, immediately star-forming gas to address how dense gas fractions and star formation efficiencies vary across and among galaxies. The extensive and sensitive data collected from EMPIRE has allowed us to relate the fraction of star-forming gas and its ability to form stars to local interstellar medium (ISM) and dynamical conditions, such as stellar surface densities, ISM dynamical pressure or molecular gas surface densities. The main results from EMPIRE show that the star formation efficiency in the dense gas varies systematically in all galactic disks. Therefore, this provides support for a context-dependent role of gas density, where dense gas fractions follow interstellar pressure, but star formation only takes place in local over-densities. The EMPIRE survey has successfully turned into a stepping stone for on-going and future projects, aiming to link the large-scale EMPIRE extragalactic results to high-resolution measurements, accessible from our Milky Way.
    Type of Medium: Online Resource
    ISSN: 2100-014X
    Language: English
    Publisher: EDP Sciences
    Publication Date: 2022
    detail.hit.zdb_id: 2595425-8
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  • 6
    In: Stroke, Ovid Technologies (Wolters Kluwer Health), Vol. 53, No. 12 ( 2022-12), p. 3728-3740
    Abstract: We aim to compare the outcome of patients from urban areas, where the referral center is able to perform thrombectomy, with patients from nonurban areas enrolled in the RACECAT trial (Direct Transfer to an Endovascular Center Compared to Transfer to the Closest Stroke Center in Acute Stroke Patients With Suspected Large Vessel Occlusion). Methods: Patients with suspected large vessel occlusion stroke, as evaluated by a Rapid Arterial Occlusion Evaluation score of ≥5, from urban catchment areas of thrombectomy-capable centers during RACECAT trial enrollment period were included in the Stroke Code Registry of Catalonia. Primary outcome was disability at 90 days, as assessed by the shift analysis on the modified Rankin Scale score, in patients with an ischemic stroke. Secondary outcomes included mortality at 90 days, rate of thrombolysis and thrombectomy, time from onset to thrombolysis, and thrombectomy initiation. Propensity score matching was used to assemble a cohort of patients with similar characteristics. Results: The analysis included 1369 patients from nonurban areas and 2502 patients from urban areas. We matched 920 patients with an ischemic stroke from urban areas and nonurban areas based on their propensity scores. Patients with ischemic stroke from nonurban areas had higher degrees of disability at 90 days (median [interquartle range] modified Rankin Scale score, 3 [2–5] versus 3 [1–5], common odds ratio, 1.25 [95% CI, 1.06–1.48] ); the observed average effect was only significant in patients with large vessel stroke (common odds ratio, 1.36 [95% CI, 1.08–1.65]). Mortality rate was similar between groups(odds ratio, 1.02 [95% CI, 0.81–1.28] ). Patients from nonurban areas had higher odds of receiving thrombolysis (odds ratio, 1.36 [95% CI, 1.16–1.67]), lower odds of receiving thrombectomy(odds ratio, 0.61 [95% CI, 0.51–0.75] ), and longer time from stroke onset to thrombolysis (mean difference 38 minutes [95% CI, 25–52]) and thrombectomy(mean difference 66 minutes [95% CI, 37–95] ). Conclusions: In Catalonia, Spain, patients with large vessel occlusion stroke triaged in nonurban areas had worse neurological outcomes than patients from urban areas, where the referral center was able to perform thrombectomy. Interventions aimed at improving organizational practices and the development of thrombectomy capabilities in centers located in remote areas should be pursued. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02795962.
    Type of Medium: Online Resource
    ISSN: 0039-2499 , 1524-4628
    RVK:
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2022
    detail.hit.zdb_id: 1467823-8
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  • 7
    In: Stroke, Ovid Technologies (Wolters Kluwer Health), Vol. 54, No. 3 ( 2023-03), p. 770-780
    Abstract: We aim to assess whether time of day modified the treatment effect in the RACECAT trial (Direct Transfer to an Endovascular Center Compared to Transfer to the Closest Stroke Center in Acute Stroke Patients With Suspected Large Vessel Occlusion Trial), a cluster-randomized trial that did not demonstrate the benefit of direct transportation to a thrombectomy-capable center versus nearest local stroke center for patients with a suspected large vessel stroke triaged in nonurban Catalonia between March 2017 and June 2020. Methods: We performed a post hoc analysis of RACECAT to evaluate if the association between initial transport routing and functional outcome differed according to trial enrollment time: daytime (8:00 am –8:59 pm ) and nighttime (9:00 pm –7:59 am ). Primary outcome was disability at 90 days, as assessed by the shift analysis on the modified Rankin Scale score, in patients with ischemic stroke. Subgroup analyses according to stroke subtype were evaluated. Results: We included 949 patients with an ischemic stroke, of whom 258 patients(27%) were enrolled during nighttime. Among patients enrolled during nighttime, direct transport to a thrombectomy-capable center was associated with lower degrees of disability at 90 days (adjusted common odds ratio [acOR] , 1.620 [95% CI, 1.020–2.551]); no significant difference between trial groups was present during daytime (acOR, 0.890 [95% CI, 0.680–1.163] ; P interaction =0.014). Influence of nighttime on the treatment effect was only evident in patients with large vessel occlusion(daytime, acOR 0.766 [95% CI, 0.548–1.072]; nighttime, acOR, 1.785 [95% CI, 1.024–3.112] ; P interaction 〈 0.01); no heterogeneity was observed for other stroke subtypes ( P interaction 〉 0.1 for all comparisons). We observed longer delays in alteplase administration, interhospital transfers, and mechanical thrombectomy initiation during nighttime in patients allocated to local stroke centers. Conclusions: Among patients evaluated during nighttime for a suspected acute severe stroke in non-urban areas of Catalonia, direct transport to a thrombectomy-capable center was associated with lower degrees of disability at 90 days. This association was only evident in patients with confirmed large vessel occlusion on vascular imaging. Time delays in alteplase administration and interhospital transfers might mediate the observed differences in clinical outcome. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02795962.
    Type of Medium: Online Resource
    ISSN: 0039-2499 , 1524-4628
    RVK:
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2023
    detail.hit.zdb_id: 1467823-8
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  • 8
    In: JAMA, American Medical Association (AMA), Vol. 327, No. 18 ( 2022-05-10), p. 1782-
    Abstract: In nonurban areas with limited access to thrombectomy-capable centers, optimal prehospital transport strategies in patients with suspected large-vessel occlusion stroke are unknown. Objective To determine whether, in nonurban areas, direct transport to a thrombectomy-capable center is beneficial compared with transport to the closest local stroke center. Design, Setting, and Participants Multicenter, population-based, cluster-randomized trial including 1401 patients with suspected acute large-vessel occlusion stroke attended by emergency medical services in areas where the closest local stroke center was not capable of performing thrombectomy in Catalonia, Spain, between March 2017 and June 2020. The date of final follow-up was September 2020. Interventions Transportation to a thrombectomy-capable center (n = 688) or the closest local stroke center (n = 713). Main Outcomes and Measures The primary outcome was disability at 90 days based on the modified Rankin Scale (mRS; scores range from 0 [no symptoms] to 6 [death] ) in the target population of patients with ischemic stroke. There were 11 secondary outcomes, including rate of intravenous tissue plasminogen activator administration and thrombectomy in the target population and 90-day mortality in the safety population of all randomized patients. Results Enrollment was halted for futility following a second interim analysis. The 1401 enrolled patients were included in the safety analysis, of whom 1369 (98%) consented to participate and were included in the as-randomized analysis (56% men; median age, 75 [IQR, 65-83] years; median National Institutes of Health Stroke Scale score, 17 [IQR, 11-21] ); 949 (69%) comprised the target ischemic stroke population included in the primary analysis. For the primary outcome in the target population, median mRS score was 3 (IQR, 2-5) vs 3 (IQR, 2-5) (adjusted common odds ratio [OR], 1.03; 95% CI, 0.82-1.29). Of 11 reported secondary outcomes, 8 showed no significant difference. Compared with patients first transported to local stroke centers, patients directly transported to thrombectomy-capable centers had significantly lower odds of receiving intravenous tissue plasminogen activator (in the target population, 229/482 [47.5%] vs 282/467 [60.4%]; OR, 0.59; 95% CI, 0.45-0.76) and significantly higher odds of receiving thrombectomy (in the target population, 235/482 [48.8%] vs 184/467 [39.4%]; OR, 1.46; 95% CI, 1.13-1.89). Mortality at 90 days in the safety population was not significantly different between groups (188/688 [27.3%] vs 194/713 [27.2%]; adjusted hazard ratio, 0.97; 95% CI, 0.79-1.18). Conclusions and Relevance In nonurban areas in Catalonia, Spain, there was no significant difference in 90-day neurological outcomes between transportation to a local stroke center vs a thrombectomy-capable referral center in patients with suspected large-vessel occlusion stroke. These findings require replication in other settings. Trial Registration ClinicalTrials.gov Identifier: NCT02795962
    Type of Medium: Online Resource
    ISSN: 0098-7484
    RVK:
    Language: English
    Publisher: American Medical Association (AMA)
    Publication Date: 2022
    detail.hit.zdb_id: 2958-0
    detail.hit.zdb_id: 2018410-4
    SSG: 5,21
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  • 9
    In: Magnetic Resonance in Chemistry, Wiley, Vol. 31, No. 13 ( 1993-12)
    Abstract: 1 H two‐dimensional NMR experiments on nickel(II)‐substituted azurin have been successfully applied. Despite the short relaxation times of the hyperfine‐shifted resonances, the combined use of NOESY and COSY spectra allowed the assignment of 15 resonances belonging to the metal‐coordinated residues Gly‐45, His‐46, His‐117 and Met‐121. Even in the case of the two broad and furthest downfield resonances, the NOESY spectra were successful in assigning these signals to the β‐CH 2 protons of Cys‐112. The protons of the non‐coordinated residues Met‐13, Phe‐15 and Trp‐48 were also assigned via NOESY, COSY and TOCSY experiments.
    Type of Medium: Online Resource
    ISSN: 0749-1581 , 1097-458X
    URL: Issue
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    Language: English
    Publisher: Wiley
    Publication Date: 1993
    detail.hit.zdb_id: 1475029-6
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  • 10
    In: Journal of Inorganic Biochemistry, Elsevier BV, Vol. 45, No. 4 ( 1992-3), p. 231-243
    Type of Medium: Online Resource
    ISSN: 0162-0134
    RVK:
    Language: English
    Publisher: Elsevier BV
    Publication Date: 1992
    detail.hit.zdb_id: 1491314-8
    SSG: 12
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