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- Hsiao, Tiger Yu-Yang, et al.
(författare)
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JWST Reveals a Possible z similar to 11 Galaxy Merger in Triply Lensed MACS0647-JD
- 2023
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Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8205 .- 2041-8213. ; 949:2
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Tidskriftsartikel (refereegranskat)abstract
- MACS0647-JD is a triply lensed z similar to 11 galaxy originally discovered with the Hubble Space Telescope. The three lensed images are magnified by factors of similar to 8, 5, and 2 to AB mag 25.1, 25.6, and 26.6 at 3.5 mu m. The brightest is over a magnitude brighter than other galaxies recently discovered at similar redshifts z > 10 with JWST. Here, we report new JWST imaging that clearly resolves MACS0647-JD as having two components that are either merging galaxies or stellar complexes within a single galaxy. The brighter larger component "A" is intrinsically very blue (ss similar to-2.6 +/- 0.1), likely due to very recent star formation and no dust, and is spatially extended with an effective radius similar to 70 +/- 24 pc. The smaller component "B" (r similar to 20-+ 58 pc) appears redder (ss similar to-2 +/- 0.2), likely because it is older (100-200 Myr) with mild dust extinction (AV similar to 0.1 mag). With an estimated stellar mass ratio of roughly 2:1 and physical projected separation similar to 400 pc, we may be witnessing a galaxy merger 430 million years after the Big Bang. We identify galaxies with similar colors in a high-redshift simulation, finding their star formation histories to be dissimilar, which is also suggested by the spectral energy distribution fitting, suggesting they formed further apart. We also identify a candidate companion galaxy "C" similar to 3 kpc away, likely destined to merge with A and B. Upcoming JWST Near Infrared Spectrograph observations planned for 2023 January will deliver spectroscopic redshifts and more physical properties for these tiny magnified distant galaxies observed in the early universe.
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| 2. |
- Olivier, Cecille, et al.
(författare)
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New strategies for the conduct of clinical trials in paediatric Pulmonary Arterial Hypertension (PAH): Outcome of a multi-stakeholder meeting with patients, academia, industry and regulators held at EMA on Monday 12th June 2017
- 2019
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Ingår i: Journal of the American Heart Association. - 2047-9980. ; 8:10, s. 1-10
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Forskningsöversikt (refereegranskat)abstract
- Aims: Drug development for paediatric pulmonary arterial hypertension (PAH) ispressingly needed. Experts from the US Food and Drug Administration, EuropeanMedicines Agency, Health Canada, key opinion leaders, academia, patients, and industry representatives held a workshop on 12th June 2017 dedicated to addressing challenges and unmet needs. This report summarises the approaches proposed during the meeting to address key issues in extrapolation, trial design, and study endpoints in pediatric drug development.Methods and Results: A pre-workshop stakeholder survey was conducted and showed that most respondents believe the pathophysiology of heritable PAH and some forms of idiopathic PAH is thought to be sufficiently similar in adult and paediatric patients, although the clinical manifestations may differ. In this situation, placebo-controlled trials might not be required to confirm clinical benefit in paediatrics. The study endpoints used to support drug approvals in adults were reviewed to determine if these existing study endpoints can be applied in paediatric PAH efficacy trials. It showed that non-invasive study endpoints, such as the time to clinical worsening, WHO functionalclass, and 6-Minute-Walk-Test could be applicable in paediatric PAH trials, although each presents some limitations in paediatrics.Conclusion: Extrapolation of efficacy from informative adult studies may be appropriate in some forms of PAH. Initial dose-finding studies and exposure-response modelling are warranted in paediatric PAH, followed by an efficacy and safety study to explore the response to treatment and exposure-response relationship. A novel, non-invasive, developmentally-appropriate, and reliable study endpoint needs to be developed.
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| 3. |
- Scuteri, Angelo, et al.
(författare)
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Arterial stiffness and influences of the metabolic syndrome: A cross-countries study.
- 2014
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Ingår i: Atherosclerosis. - : Elsevier BV. - 1879-1484 .- 0021-9150. ; 233:2, s. 654-660
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Tidskriftsartikel (refereegranskat)abstract
- Specific clusters of metabolic syndrome (MetS) components impact differentially on arterial stiffness, indexed as pulse wave velocity (PWV). Of note, in several population-based studies participating in the MARE (Metabolic syndrome and Arteries REsearch) Consortium the occurrence of specific clusters of MetS differed markedly across Europe and the US. The aim of the present study was to investigate whether specific clusters of MetS are consistently associated with stiffer arteries in different populations. We studied 20,570 subjects from 9 cohorts representing 8 different European countries and the US participating in the MARE Consortium. MetS was defined in accordance with NCEP ATPIII criteria as the simultaneous alteration in ≥3 of the 5 components: abdominal obesity (W), high triglycerides (T), low HDL cholesterol (H), elevated blood pressure (B), and elevated fasting glucose (G). PWV measured in each cohort was "normalized" to account for different acquisition methods. MetS had an overall prevalence of 24.2% (4985 subjects). MetS accelerated the age-associated increase in PWV levels at any age, and similarly in men and women. MetS clusters TBW, GBW, and GTBW are consistently associated with significantly stiffer arteries to an extent similar or greater than observed in subjects with alteration in all the five MetS components - even after controlling for age, sex, smoking, cholesterol levels, and diabetes mellitus - in all the MARE cohorts. In conclusion, different component clusters of MetS showed varying associations with arterial stiffness (PWV).
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| 4. |
- Scuteri, Angelo, et al.
(författare)
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Metabolic syndrome across Europe: Different clusters of risk factors
- 2015
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Ingår i: European Journal of Preventive Cardiology. - : Oxford University Press (OUP). - 2047-4881 .- 2047-4873. ; 22:4, s. 486-491
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Tidskriftsartikel (refereegranskat)abstract
- Background: Metabolic syndrome (MetS) remains a controversial entity. Specific clusters of MetS components - rather than MetS per se - are associated with accelerated arterial ageing and with cardiovascular (CV) events. To investigate whether the distribution of clusters of MetS components differed cross-culturally, we studied 34,821 subjects from 12 cohorts from 10 European countries and one cohort from the USA in the MARE (Metabolic syndrome and Arteries REsearch) Consortium. Methods: In accordance with the ATP III criteria, MetS was defined as an alteration three or more of the following five components: elevated glucose (G), fasting glucose >= 110 mg/dl; low HDL cholesterol, <40mg/dl for men or <50 mg/dl for women; high triglycerides (T), >= 150 mg/dl; elevated blood pressure (B), >= 130/ >= 85 mmHg; abdominal obesity (W), waist circumference >102 cm for men or >88 cm for women. Results: MetS had a 24.3% prevalence (8468 subjects: 23.9% in men vs. 24.6% in women, p < 0.001) with an age-associated increase in its prevalence in all the cohorts. The age-adjusted prevalence of the clusters of MetS components previously associated with greater arterial and CV burden differed across countries (p < 0.0001) and in men and women (p < 0.0001). In details, the cluster TBW was observed in 12% of the subjects with MetS, but was far more common in the cohorts from the UK (32.3%), Sardinia in Italy (19.6%), and Germany (18.5%) and less prevalent in the cohorts from Sweden (1.2%), Spain (2.6%), and the USA (2.5%). The cluster GBW accounted for 12.7% of subjects with MetS with higher occurrence in Southern Europe (Italy, Spain, and Portugal: 31.4, 18.4, and 17.1% respectively) and in Belgium (20.4%), than in Northern Europe (Germany, Sweden, and Lithuania: 7.6, 9.4, and 9.6% respectively). Conclusions: The analysis of the distribution of MetS suggested that what follows under the common definition of MetS is not a unique entity rather a constellation of cluster of MetS components, likely selectively risky for CV disease, whose occurrence differs across countries.
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| 5. |
- Welch, Brian, et al.
(författare)
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JWST Imaging of Earendel, the Extremely Magnified Star at Redshift z=6.2
- 2022
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Ingår i: Astrophysical Journal Letters. - : Institute of Physics (IOP). - 2041-8205 .- 2041-8213. ; 940
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Tidskriftsartikel (refereegranskat)abstract
- The gravitationally lensed star WHL 0137-LS, nicknamed Earendel, was identified with a photometric redshift z (phot) = 6.2 +/- 0.1 based on images taken with the Hubble Space Telescope. Here we present James Webb Space Telescope (JWST) Near Infrared Camera images of Earendel in eight filters spanning 0.8-5.0 mu m. In these higher-resolution images, Earendel remains a single unresolved point source on the lensing critical curve, increasing the lower limit on the lensing magnification to mu > 4000 and restricting the source plane radius further to r < 0.02 pc, or similar to 4000 au. These new observations strengthen the conclusion that Earendel is best explained by an individual star or multiple star system and support the previous photometric redshift estimate. Fitting grids of stellar spectra to our photometry yields a stellar temperature of T (eff) similar to 13,000-16,000 K, assuming the light is dominated by a single star. The delensed bolometric luminosity in this case ranges from log(L)=5.8 L-theta, which is in the range where one expects luminous blue variable stars. Follow-up observations, including JWST NIRSpec scheduled for late 2022, are needed to further unravel the nature of this object, which presents a unique opportunity to study massive stars in the first billion years of the universe.
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