16 research outputs found
Circumstellar Medium Interaction in SN 2018lab, A Low-Luminosity II-P Supernova observed with TESS
We present photometric and spectroscopic data of SN 2018lab, a low luminosity
type IIP supernova (LLSN) with a V-band peak luminosity of mag.
SN 2018lab was discovered by the Distance Less Than 40 Mpc (DLT40) SNe survey
only 0.73 days post-explosion, as determined by observations from the
Transiting Exoplanet Survey Satellite (TESS). TESS observations of SN 2018lab
yield a densely sampled, fast-rising, early time light curve likely powered by
circumstellar medium (CSM) interaction. The blue-shifted, broadened flash
feature in the earliest spectra (2 days) of SN 2018lab provide further
evidence for ejecta-CSM interaction. The early emission features in the spectra
of SN 2018lab are well described by models of a red supergiant progenitor with
an extended envelope and close-in CSM. As one of the few LLSNe with observed
flash features, SN 2018lab highlights the need for more early spectra to
explain the diversity of flash feature morphology in type II SNe
State of the knowledge on European marine habitat mapping and degraded habitats
During the last decades, several EU Directives and other international legislations have generated a large number of national initiatives (e.g. marine atlases) and EU programmes on habitat mapping. Nevertheless, the outcomes of these initiatives are fragmented and, to our best knowledge, to date there is no systematic assessment regarding the nature, quality and availability of information across the European seas. One of the main goals of the MERCES project (www.merces-project.eu) is to produce a census of available maps of European key marine habitats, along with their degradation status and restoration potential in the European Seas, providing a potential basis for future discussion on restoration activities.
MERCES is producing a census of European marine key habitat maps, degraded habitat maps and investigating key habitat restoration potential. To do this MERCES has
i. reviewed known existing habitat maps of European regional seas and provided source citations for all of the information
ii. reviewed degraded habitat map resources by regional sea and habitat type (e.g. seagrass, macroalgae, coral gardens, sponge aggregations, seamounts, vents), associated habitat deterioration (e.g. extent of decline), the most common human activities and pressures reported, and the recovery and restoration potential of these habitats
iii. reviewed 6 key habitats (including kelp and macroalgal forests, seagrass meadows, coralligenous assemblages, coral gardens and deep-sea bottom communities) and linked 6 major habitat features, such as dynamics, connectivity, structural complexity and vulnerability, to consequences for restoration and the likelihood of restoration succes
Current marine pressures and mechanisms driving changes in marine habitats
Human activities and the resultant pressures they place on the marine environment have been widely demonstrated to contribute to habitat degradation, therefore, their identification and quantification is an essential step towards any meaningful restoration effort. The overall scope of MERCES Deliverable 1.2 is to review current knowledge regarding the major marine pressures placed upon marine ecosystems in EU waters and the mechanisms by which they impact habitats in order to determine potential restoration pathways. An understanding of their geographical distribution is critical for any local assessment of degradation, as well as for planning conservation and restoration actions. This information would ideally be in the form of maps, which: (a) compile single or multiple activities and pressures over broad scales, integrating and visualizing available data and allowing direct identification of aggregations as well as gaps and (b) may be overlaid with habitat maps (or any other map layer containing additional information), thus combining different data levels and producing new information to be used for example when implementing EU policies. The deliverable also documents typical example habitat case studies, the prominent impacts and consequences of activities and pressures towards the identification of possible restoration or mitigation actions. Finally the deliverable discusses pressures, assessments, marine spatial planning and blue growth potential.
Activities and pressures are used in a strict sense, where marine activities are undertaken to satisfy the needs of societal drivers (e.g. aquaculture or tourism) and pressures are considered to be the mechanism through which an activity has an actual or potential effect on any part of the ecosystem (e.g. for demersal trawling activity, one pressure would be abrasion of the seabed). Habitats are addressed using a nested approach from large-scale geological features (e.g. shallow soft bottoms) to species-characterised habitats (e.g. Posidonia meadows) because of the way they are referred to in current policy documents which lack standard and precise definitions
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Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial.
Importance: Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited. Objective: To determine whether hydrocortisone improves outcome for patients with severe COVID-19. Design, Setting, and Participants: An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020. Interventions: The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (n = 143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (n = 152), or no hydrocortisone (n = 108). Main Outcomes and Measures: The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%). Results: After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (n = 137), shock-dependent (n = 146), and no (n = 101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively. Conclusions and Relevance: Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions. Trial Registration: ClinicalTrials.gov Identifier: NCT02735707
Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19
IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19.
Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19.
DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022).
INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days.
MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes.
RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively).
CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes.
TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570
Hotter than Expected: Hubble Space Telescope (HST)/WFC3 Phase-resolved Spectroscopy of a Rare Irradiated Brown Dwarf with Strong Internal Heat Flux
With infrared flux contrasts larger than typically seen in hot Jupiter, tidally locked white dwarf–brown dwarf binaries offer a superior opportunity to investigate atmospheric processes in irradiated atmospheres. NLTT5306 is such a system, with a M _BD = 52 ± 3 M _Jup brown dwarf, orbiting a T _eff = 7756 ± 35 K white dwarf with an ultra-short period of ∼102 minutes. We present Hubble Space Telescope/Wide Field Camera 3 spectroscopic phase curves of NLTT5306, consisting of 47 spectra from 1.1 to 1.7 μ m with an average signal-to-noise ratio ∼ 65 per wavelength. We extracted the phase-resolved spectra of the brown dwarf NLTT5306B, finding a small <100 K day–night temperature difference (∼5% of the average day-side temperature). Our best-fit model phase curves revealed a complex wavelength-dependence on amplitudes and relative phase offsets, suggesting longitudinal–vertical atmospheric structure. The night-side spectrum was well fit by a cloudy, nonirradiated atmospheric model while the day side was best matched by a cloudy, weakly irradiated model. Additionally, we created a simple radiative energy redistribution model of the atmosphere and found evidence for efficient day-to-night heat redistribution and a moderately high Bond albedo. We also discovered an internal heat flux much higher than expected given the published system age, leading to an age reassessment that resulted in NLTT5306B most likely being much younger. We find that NLTT5306B is the only known significantly irradiated brown dwarf where the global temperature structure is not dominated by external irradiation, but rather its own internal heat. Our study provides an essential insight into the drivers of global circulation and day-to-night heat transport as a function of irradiation, rotation rate, and internal heat
Interim analysis of patient recruitment, compliance and experience using smart watches for cardiac monitoring following curative-intent radiotherapy to the thorax
Habitat mapping in the European Seas - is it fit for purpose in the marine restoration agenda?
Este artículo contiene 10 páginas, 10 figuras.As habitat mapping is crucially important for developing effective management and restoration plans, the aim of this
work was to produce a census of available map resources at the European scale focusing on: a) key marine habitats; b)
degraded habitats; c) human activities and pressures acting on degraded habitats, and d) the restoration potential of
degraded habitats. Almost half of the 580 map records were derived from grey literature and web resources but
contained no georeferenced files for download, thus limiting further use of the data. Biogeographical heterogeneity was
observed and varied between the type and quality of information provided. This variability was mainly related to
differences in research efforts and stakeholder focus. Habitat degradation was assessed in only 28% of the map records
and was mostly carried out in a qualitative manner. Less than half of the map records included assessments on the
recovery/restoration potential of the degraded habitats, with passive restoration by removal of human activities being
the most commonly recommended measure. The current work has identified several gaps and challenges both in the
thematic and geographic coverage of the available map resources, as well as in the approaches implemented for the
harmonized assessment of habitat degradation. These should guide future mapping initiatives in order to more comprehensively
support and advise the marine habitat restoration agenda for better meeting the objectives set in relevant
policy documents and legislative acts in Europe.This research has received funding from the European Union’s
Horizon 2020, research and innovation programme under grant
agreement No 689518 (MERCES: Marine Ecosystem Restoration in
Changing European Seas). TM was supported by Program Investigador
FCT, Portugal (IF/01194/2013).Peer reviewe