902 research outputs found
A novel interplanetary communications relay
A case study of a potential Earth-Mars interplanetary communications relay, designed to ensure continuous communications, is detailed. The relay makes use of orbits based on artificial equilibrium points via the application of continuous low thrust, which allows a spacecraft to hover above the orbital plane of Mars and thus ensure communications when the planet is occulted with respect to the Earth. The artificial equilibria of two different low-thrust propulsion technologies are considered: solar electric propulsion, and a solar sail/solar electric propulsion hybrid. In the latter case it is shown that the combination of sail and solar electric propulsion may prove advantageous, but only under specific circumstances of the relay architecture suggested. The study takes into account factors such as the spacecraft's power requirements and communications band utilized to determine the mission and system architecture. A detailed contingency analysis is considered for recovering the relay after increasing periods of spacecraft motor failure, and combined with a consideration for how best to deploy the relay spacecraft to maximise propellant reserves and mission duration
Effect of Levodopa-Carbidopa Intestinal Gel on Non-Motor Symptoms in Patients with Advanced Parkinson\u27s Disease
Background: Levodopa-carbidopa intestinal gel (LCIG; carbidopa-levodopa enteral suspension in the United States), delivered via percutaneous gastrojejunostomy (PEG-J) and titrated in the inpatient setting, is an established treatment option for advanced Parkinson\u27s disease (PD) patients with motor fluctuations. However, long-term prospective data on the efficacy of LCIG on non-motor symptoms and the safety of outpatient titration are limited.
Methods: In this 60-week, open-label phase 3b study, LCIG titration was initiated in an outpatient setting following PEG-J placement in PD patients. The efficacy of LCIG on motor and non-motor symptoms, quality of life, and safety was assessed.
Results: Thirty-nine patients were enrolled in the study and 28 patients completed the treatment. A majority of patients (54%) completed outpatient titration within the first week of LCIG infusion. LCIG led to significant reductions from baseline in Non-Motor Symptom Scale (NMSS) total score (least squares mean ± SE = â17.6 ± 3.6, P \u3c 0.001) and 6 of the NMSS domain scores (sleep/fatigue, attention/memory, gastrointestinal tract, urinary, sexual function, miscellaneous) at week 12. These reductions were maintained at week 60 with the exception of the urinary domain. âOffâ time (â4.9 ± 0.5 hours/day, P \u3c 0.001) and âOnâ time without troublesome dyskinesia (â4.3 ± 0.6 hours/day, P \u3c 0.001) were improved at week 60. Adverse events (AEs) were reported in 37 (95%) patients.
Conclusions: LCIG treatment led to reductions in non-motor symptom burden and motor fluctuations in advanced PD patients. The safety profile was consistent with previous studies that used inpatient titration and outpatient titration did not appear to pose additional risk
InforMing the PAthway of COPD Treatment (IMPACT Trial) Single-Inhaler Triple Therapy (Fluticasone Furoate/Umeclidinium/Vilanterol) Versus Fluticasone Furoate/Vilanterol and Umeclidinium/Vilanterol in Patients With COPD: Analysis o the Western Europe and North America Regions
Chronic obstructive pulmonary disease (COPD) is a lung disease characterized by airflow limitation and progressive respiratory symptoms.1 Global public health trends estimate that the COPD burden will continue to rise, with COPD deaths estimated to increase to 4.4% of all deaths in Europe and 6.3% in the World Health Organization-defined region of the Americas by 2060.2 There are differences in the COPD burden in different regions reflecting variations in etiology,3,4 disease severity,5 symptoms,6 medication use,7 and health care systems and utilization.7 These differences may help inform therapeutic strategies to optimize therapeutic approaches to reducing symptoms and exacerbation risk.1
In the global InforMing the PAthway of COPD Treatment (IMPACT) trial, single-inhaler triple therapy fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) reduced moderate/severe exacerbation rates and improved lung function and health-related quality of life versus FF/VI or UMEC/VI dual therapy in patients â„40 years of age with symptomatic COPD and a history of exacerbations.8 Within trial populations, regional differences such as patient characteristics, treatment patterns, access to care and cultural/socioeconomic factors may dictate treatment choices and influence disease severity and progression in particular geographical locations. For example, a meta-analysis conducted in 2015 comprising 123 studies between 1990 and 2010 found that the overall prevalence of COPD as well as the rate of increase was higher in the Americas (including both North and South America) compared with Europe.9 Furthermore, a cross-sectional study assessing the burden of COPD symptoms in the United States and Europe found variations between patients across countries who had experienced at least 1 symptom of COPD.10 In Europe, patients with more frequent symptoms were more likely to experience worsening of symptoms and unexpected hospitalization. Whereas in the United States, patients with more frequent symptoms were not only more likely to experience worsening of symptoms but also longer lasting symptoms and a longer length of exacerbations.10 A further difference was that treatment adherence was higher in the United States than Europe, however, adherence was consistent across patients in Europe when assessed by modified Global initiative for chronic Obstructive Lung Disease (GOLD) 2014 groups11 but varied in the United States with adherence highest in the GOLD Group C and lowest in Group A.10 Therefore, it is important to evaluate how overall population results pertain to patients treated in particular regions. As IMPACT is one of the largest trials conducted in patients with COPD to date, we have the unique opportunity to analyze study outcomes in patients enrolled in Western Europe and North America, the 2 main regions from an enrollment perspective
Observation of two new baryon resonances
Two structures are observed close to the kinematic threshold in the mass spectrum in a sample of proton-proton collision data, corresponding
to an integrated luminosity of 3.0 fb recorded by the LHCb experiment.
In the quark model, two baryonic resonances with quark content are
expected in this mass region: the spin-parity and
states, denoted and .
Interpreting the structures as these resonances, we measure the mass
differences and the width of the heavier state to be
MeV,
MeV,
MeV, where the first and second
uncertainties are statistical and systematic, respectively. The width of the
lighter state is consistent with zero, and we place an upper limit of
MeV at 95% confidence level. Relative
production rates of these states are also reported.Comment: 17 pages, 2 figure
Search for hidden-sector bosons in decays
A search is presented for hidden-sector bosons, , produced in the decay
, with and
. The search is performed using -collision data
corresponding to 3.0 fb collected with the LHCb detector. No significant
signal is observed in the accessible mass range
MeV, and upper limits are placed on the branching fraction product
as
a function of the mass and lifetime of the boson. These limits are of
the order of for lifetimes less than 100 ps over most of the
range, and place the most stringent constraints to date on many
theories that predict the existence of additional low-mass bosons.Comment: All figures and tables, along with supplementary material, are
available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-036.htm
Study of and decays and determination of the CKM angle
We report a study of the suppressed and favored
decays, where the neutral meson is detected
through its decays to the and CP-even and
final states. The measurement is carried out using a proton-proton
collision data sample collected by the LHCb experiment, corresponding to an
integrated luminosity of 3.0~fb. We observe the first significant
signals in the CP-even final states of the meson for both the suppressed
and favored modes, as well as
in the doubly Cabibbo-suppressed final state of the decay. Evidence for the ADS suppressed decay , with , is also presented. From the observed
yields in the , and their
charge conjugate decay modes, we measure the value of the weak phase to be
. This is one of the most precise
single-measurement determinations of to date.Comment: 22 pages, 9 figures; All figures and tables, along with any
supplementary material and additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-020.htm
Observation of resonances consistent with pentaquark states in decays
Observations of exotic structures in the channel, that we refer to
as pentaquark-charmonium states, in decays are
presented. The data sample corresponds to an integrated luminosity of 3/fb
acquired with the LHCb detector from 7 and 8 TeV pp collisions. An amplitude
analysis is performed on the three-body final-state that reproduces the
two-body mass and angular distributions. To obtain a satisfactory fit of the
structures seen in the mass spectrum, it is necessary to include two
Breit-Wigner amplitudes that each describe a resonant state. The significance
of each of these resonances is more than 9 standard deviations. One has a mass
of MeV and a width of MeV, while the second
is narrower, with a mass of MeV and a width of MeV. The preferred assignments are of opposite parity, with one
state having spin 3/2 and the other 5/2.Comment: 48 pages, 18 figures including the supplementary material, v2 after
referee's comments, now 19 figure
Search for the rare decays and
A search for the rare decay of a or meson into the final
state is performed, using data collected by the LHCb experiment
in collisions at and TeV, corresponding to an integrated
luminosity of 3 fb. The observed number of signal candidates is
consistent with a background-only hypothesis. Branching fraction values larger
than for the decay mode are
excluded at 90% confidence level. For the decay
mode, branching fraction values larger than are excluded at
90% confidence level, this is the first branching fraction limit for this
decay.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-044.htm
A model-independent confirmation of the state
The decay is analyzed using of
collision data collected with the LHCb detector. A model-independent
description of the mass spectrum is obtained, using as input the
mass spectrum and angular distribution derived directly from data,
without requiring a theoretical description of resonance shapes or their
interference. The hypothesis that the mass spectrum can be
described in terms of reflections alone is rejected with more than
8 significance. This provides confirmation, in a model-independent way,
of the need for an additional resonant component in the mass region of the
exotic state.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-038.htm
Study of boson production in association with beauty and charm
The associated production of a boson with a jet originating from either a
light parton or heavy-flavor quark is studied in the forward region using
proton-proton collisions. The analysis uses data corresponding to integrated
luminosities of 1.0 and collected with the LHCb detector
at center-of-mass energies of 7 and 8 TeV, respectively. The bosons are
reconstructed using the decay and muons with a transverse
momentum, , larger than 20 GeV in the pseudorapidity range
GeV
and . The sum of the muon and jet momenta must satisfy
GeV. The fraction of jet events that originate from beauty
and charm quarks is measured, along with the charge asymmetries of the
and production cross-sections. The ratio of the jet to
jet production cross-sections is also measured using the
decay. All results are in agreement with Standard Model predictions
- âŠ