Publications by authors named "Michelson P"

Background: The goal of cystic fibrosis transmembrane conductance regulator (CFTR) modulators is to reach normal CFTR function in people with cystic fibrosis. Vanzacaftor-tezacaftor-deutivacaftor restored CFTR function in vitro and in phase 2 trials in participants aged 18 years and older resulting in improvements in CFTR function, as measured by sweat chloride concentrations and lung function as measured by spirometry. We aimed to evaluate the efficacy and safety of vanzacaftor-tezacaftor-deutivacaftor compared with standard of care elexacaftor-tezacaftor-ivacaftor in individuals with cystic fibrosis aged 12 years and older.

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Background: Advanced cystic fibrosis lung disease (ACFLD) is common, is associated with reduced quality of life, and remains the most frequent cause of death in individuals with cystic fibrosis (CF). These consensus guidelines provide recommendations to the CF community on management of both common and unique issues that arise when individuals reach a state of ACFLD.

Methods: The CF Foundation assembled a multidisciplinary expert panel consisting of three workgroups: Pulmonary management; Management of comorbid conditions; Symptom management and psychosocial issues.

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Undernutrition is common in cystic fibrosis (CF) and is correlated with long-term outcomes, yet current nutritional interventions have not demonstrated consistent improvements in energy intake, and subsequently, growth. Development of novel nutritional interventions to increase energy intake is essential to improve clinical outcomes of individuals with CF. Ready-to-use supplemental food (RUSF) is a modifiable, inexpensive, palatable, safe, and nutrient-dense food for treatment or prevention of acute malnutrition in developing countries.

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The gamma-ray sky has been observed with unprecedented accuracy in the last decade by the Fermi -large area telescope (LAT), allowing us to resolve and understand the high-energy Universe. The nature of the remaining unresolved emission [unresolved gamma-ray background (UGRB)] below the LAT source detection threshold can be uncovered by characterizing the amplitude and angular scale of the UGRB fluctuation field. This Letter presents a measurement of the UGRB autocorrelation angular power spectrum based on eight years of Fermi-LAT Pass 8 data products.

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We use joint observations by the X-ray Telescope (XRT) and the Large Area Telescope (LAT) of gamma-ray burst (GRB) afterglows to investigate the nature of the long-lived high-energy emission observed by LAT. Joint broadband spectral modeling of XRT and LAT data reveal that LAT non-detections of bright X-ray afterglows are consistent with a cooling break in the inferred electron synchrotron spectrum below the LAT and/or XRT energy ranges. Such a break is sufficient to suppress the high-energy emission so as to be below the LAT detection threshold.

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Objective: The purpose of this study was to describe the variability and test-retest reliability of a commercially available subjective visual vertical (SVV) system known as Virtual SVV (Interacoustics). In addition, the study aimed to compare the reliability of the Virtual system with a previously established bucket test of SVV.

Study Design: Fifteen participants with normal hearing, normal middle ear function, and normal utricular function were included in the study.

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Objective: To evaluate the effectiveness of a physician-led rapid response team program on morbidity and mortality following unplanned admission to the PICU.

Design: Before-after study.

Setting: Single-center quaternary-referral PICU.

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Millisecond pulsars (MSPs) are old neutron stars that spin hundreds of times per second and appear to pulsate as their emission beams cross our line of sight. To date, radio pulsations have been detected from all rotation-powered MSPs. In an attempt to discover radio-quiet gamma-ray MSPs, we used the aggregated power from the computers of tens of thousands of volunteers participating in the Einstein@Home distributed computing project to search for pulsations from unidentified gamma-ray sources in Fermi Large Area Telescope data.

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The Large Area Telescope on board the Fermi Gamma-ray Space Telescope has collected the largest ever sample of high-energy cosmic-ray electron and positron events since the beginning of its operation. Potential anisotropies in the arrival directions of cosmic-ray electrons or positrons could be a signature of the presence of nearby sources. We use almost seven years of data with energies above 42 GeV processed with the Pass 8 reconstruction.

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We report on the search for spectral irregularities induced by oscillations between photons and axionlike-particles (ALPs) in the γ-ray spectrum of NGC 1275, the central galaxy of the Perseus cluster. Using 6 years of Fermi Large Area Telescope data, we find no evidence for ALPs and exclude couplings above 5×10^{-12}  GeV^{-1} for ALP masses 0.5≲m_{a}≲5  neV at 95% confidence.

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The Fermi Large Area Telescope (LAT) Collaboration has recently released a catalog of 360 sources detected above 50 GeV (2FHL). This catalog was obtained using 80 months of data re-processed with Pass 8, the newest event-level analysis, which significantly improves the acceptance and angular resolution of the instrument. Most of the 2FHL sources at high Galactic latitude are blazars.

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We have measured the gamma-ray emission spectrum of the Moon using the data collected by the Large Area Telescope onboard the Fermi satellite during its first seven years of operation, in the energy range from 30 MeV up to a few GeV. We have also studied the time evolution of the flux, finding a correlation with the solar activity. We have developed a full Monte Carlo simulation describing the interactions of cosmic rays with the lunar surface.

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The dwarf spheroidal satellite galaxies (dSphs) of the Milky Way are some of the most dark matter (DM) dominated objects known. We report on γ-ray observations of Milky Way dSphs based on six years of Fermi Large Area Telescope data processed with the new Pass8 event-level analysis. None of the dSphs are significantly detected in γ rays, and we present upper limits on the DM annihilation cross section from a combined analysis of 15 dSphs.

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Background: Flexible airway endoscopy (FAE) is an accepted and frequently performed procedure in the evaluation of children with known or suspected airway and lung parenchymal disorders. However, published technical standards on how to perform FAE in children are lacking.

Methods: The American Thoracic Society (ATS) approved the formation of a multidisciplinary committee to delineate technical standards for performing FAE in children.

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Purpose: To evaluate the effects of oral N-acetylcysteine (NAC), which replenishes systemic glutathione, on decreasing inflammation and improving lung function in CF airways.

Methods: A multicenter, randomized, double-blind proof of concept study in which 70 CF subjects received NAC or placebo orally thrice daily for 24 weeks.

Endpoints: primary, change in sputum human neutrophil elastase (HNE) activity; secondary, FEV(1) and other clinical lung function measures; and safety, the safety and tolerability of NAC and the potential of NAC to promote pulmonary hypertension in subjects with CF.

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Article Synopsis
  • Recent measurements from ATIC-2, CREAM, and PAMELA have revealed unexpected patterns in cosmic-ray proton and helium spectra, showing hardening above several hundred GeV and a gradual softening below this range.
  • The findings suggest a harder spectrum for helium compared to protons, which may provide insights into the origins of high-energy cosmic rays.
  • Analysis using Fermi Large Area Telescope data indicates that both single and broken power law models fit the local proton spectrum well, with indices around 2.68 and 2.61 for energies above 200 GeV.
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Observations of occultations of bright -ray sources by the Sun may reveal predicted pair halos around blazars andor new physics, such as, e.g., hypothetical light dark matter particles-axions.

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The observations of the exceptionally bright gamma-ray burst (GRB) 130427A by the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope provide constraints on the nature of these unique astrophysical sources. GRB 130427A had the largest fluence, highest-energy photon (95 GeV), longest γ-ray duration (20 hours), and one of the largest isotropic energy releases ever observed from a GRB. Temporal and spectral analyses of GRB 130427A challenge the widely accepted model that the nonthermal high-energy emission in the afterglow phase of GRBs is synchrotron emission radiated by electrons accelerated at an external shock.

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Gamma-ray burst (GRB) 130427A is one of the most energetic GRBs ever observed. The initial pulse up to 2.5 seconds is possibly the brightest well-isolated pulse observed to date.

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Background: Congenital pulmonary vein stenosis (PVS) is associated with high mortality because surgical repair is usually not feasible or is ineffective. In addition, acquired PVS after repair of congenital heart disease is a potential complication that occurs in 5% to 10% of patients and carries a poor prognosis. Lung transplantation has been proposed as a viable option.

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Cosmic rays are particles (mostly protons) accelerated to relativistic speeds. Despite wide agreement that supernova remnants (SNRs) are the sources of galactic cosmic rays, unequivocal evidence for the acceleration of protons in these objects is still lacking. When accelerated protons encounter interstellar material, they produce neutral pions, which in turn decay into gamma rays.

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The light emitted by stars and accreting compact objects through the history of the universe is encoded in the intensity of the extragalactic background light (EBL). Knowledge of the EBL is important to understand the nature of star formation and galaxy evolution, but direct measurements of the EBL are limited by galactic and other foreground emissions. Here, we report an absorption feature seen in the combined spectra of a sample of gamma-ray blazars out to a redshift of z ∼ 1.

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Millisecond pulsars, old neutron stars spun up by accreting matter from a companion star, can reach high rotation rates of hundreds of revolutions per second. Until now, all such "recycled" rotation-powered pulsars have been detected by their spin-modulated radio emission. In a computing-intensive blind search of gamma-ray data from the Fermi Large Area Telescope (with partial constraints from optical data), we detected a 2.

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We measured separate cosmic-ray electron and positron spectra with the Fermi Large Area Telescope. Because the instrument does not have an onboard magnet, we distinguish the two species by exploiting Earth's shadow, which is offset in opposite directions for opposite charges due to Earth's magnetic field. We estimate and subtract the cosmic-ray proton background using two different methods that produce consistent results.

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