3,753 research outputs found
Kepler-445, Kepler-446 And The Occurrence Of Compact Multiples Orbiting Mid-M Dwarf Stars
We confirm and characterize the exoplanetary systems Kepler-445 and Kepler-446: two mid-M dwarf stars, each with multiple, small, short-period transiting planets. Kepler-445 is a metal-rich ([ Fe/H] = + 0.25 0.10) M4 dwarf with three transiting planets, and Kepler-446 is a metal-poor ([ Fe/H] = -0.30 0.10) M4 dwarf also with three transiting planets. Kepler-445c is similar toGJ 1214b: both in planetary radius and the properties of the host star. The Kepler-446 system is similar to the Kepler-42 system: both are metal-poor with large galactic space velocities and three short-period, likely rocky transiting planets that were initially assigned erroneously large planet-to-star radius ratios. We independently determined stellar parameters from spectroscopy and searched for and fitted the transit light curves for the planets, imposing a strict prior on stellar density in order to remove correlations between the fitted impact parameter and planet-to-star radius ratio for short-duration transits. Combining Kepler-445, Kepler-446, and Kepler-42, and isolating all mid-M dwarf stars observed by Kepler with the precision necessary to detect similar systems, we calculate that 21+ 7 -5 % of mid-M dwarf stars host compact multiples ( multiple planets with periods of less than 10 days) for a wide range of metallicities. We suggest that the inferred planet masses for these systems support highly efficient accretion of protoplanetary disk metals by mid-M dwarf protoplanets.NSF DGE1144152, AST-1005313NASA NAS5-26555NASA Office of Space Science NNX13AC07GAstronom
Attenuation of Traumatic Brain Injury-Induced Cognitive Impairment in Mice by Targeting Increased Cytokine Levels with a Small Molecule Experimental Therapeutic
BACKGROUND: Evidence from clinical studies and preclinical animal models suggests that proinflammatory cytokine overproduction is a potential driving force for pathology progression in traumatic brain injury (TBI). This raises the possibility that selective targeting of the overactive cytokine response, a component of the neuroinflammation that contributes to neuronal dysfunction, may be a useful therapeutic approach. MW151 is a CNS-penetrant, small molecule experimental therapeutic that selectively restores injury- or disease-induced overproduction of proinflammatory cytokines towards homeostasis. We previously reported that MW151 administered post-injury (p.i.) is efficacious in a closed head injury (CHI) model of diffuse TBI in mice. Here we test dose dependence of MW151 to suppress the target mechanism (proinflammatory cytokine up-regulation), and explore the therapeutic window for MW151 efficacy.
METHODS: We examined suppression of the acute cytokine surge when MW151 was administered at different times post-injury and the dose-dependence of cytokine suppression. We also tested a more prolonged treatment with MW151 over the first 7 days post-injury and measured the effects on cognitive impairment and glial activation.
RESULTS: MW151 administered up to 6 h post-injury suppressed the acute cytokine surge, in a dose-dependent manner. Administration of MW151 over the first 7 days post-injury rescues the CHI-induced cognitive impairment and reduces glial activation in the focus area of the CHI.
CONCLUSIONS: Our results identify a clinically relevant time window post-CHI during which MW151 effectively restores cytokine production back towards normal, with a resultant attenuation of downstream cognitive impairment
A New FUSE Survey of Interstellar HD
We have used archival FUSE data to complete a survey of interstellar HD in 41
lines of sight with a wide range of extinctions. This follow up to an earlier
survey was made to further assess the utility of HD as a cosmological probe; to
analyze the HD formation process; and to see what trends with other
interstellar properties were present in the data. We employed the
curve-of-growth method, supported by line profile fitting, to derive accurate
column densities of HD. We find that the N(HD)/2N(H2) ratio is substantially
lower than the atomic D/H ratio and conclude that the molecular ratio has no
bearing on cosmology, because local processes are responsible for the formation
of HD. Based on correlations with E(B-V), H2, CO, and iron depletion, we find
that HD is formed in the densest portion of the clouds; the slope of the
logN(HD)/log(H2) correlation is greater than 1.0, caused by the destruction
rate of HD declining more slowly than that of H2; and, as a sidelight, that the
depletions are density dependent.Comment: 30 pages, 13 figures; Accepted for publication in Ap
Group 5 ITI Consensus Report: Implant placement and loading protocols
ObjectivesWorking Group 5 was convened to discuss and find consensus on the topics of implant placement and loading protocols associated with single missing teeth in the anterior maxilla (aesthetic zone). Consensus statements, clinical recommendations, patient perspectives and future research suggestions were developed and presented to the plenary for discussion and approval.Materials and MethodsTwo systematic reviews were developed and submitted prior to the conference. The group considered in detail the systematic reviews and developed statements, clinical recommendations, patient perspectives and future research suggestions based on the findings of the reviews and experience of group members. Definitive versions were developed after presentation to and discussion by the plenary.ResultsFive consensus statements were developed and approved from each systematic review. Twelve clinical recommendations were developed by the group based on both reviews and experience. Three patient perspectives were developed, and five suggestions made for future research.ConclusionsBased on the findings of the systematic reviews and experience of group members, the Type 1A protocol (immediate placement and immediate loading), when utilized in the anterior maxilla under favorable conditions, is considered predictable and is associated with high survival rates. The procedure is considered clinically viable and is associated with aesthetic outcomes, although surgical, technical, and biological complications can occur
S-wave eta'-proton FSI; phenomenological analysis of near-threshold production of pi0, eta, and eta' mesons in proton-proton collisions
We describe a novel technique for comparing total cross sections for the
reactions pp --> pp pi(0), pp --> pp eta, and pp --> pp eta' close to
threshold. The initial and final state proton-proton interactions are factored
out of the total cross section, and the dependence of this reduced cross
section on the volume of phase space is discussed. Different models of the
proton-proton interaction are compared. We argue that the scattering length of
the S-wave eta'-proton interaction is of the order of 0.1 fm.Comment: 10 pages, 5 figure
Dual bronchodilators in Bronchiectasis study (DIBS): protocol for a pragmatic, multicentre, placebo-controlled, three-arm, double-blinded, randomised controlled trial studying bronchodilators in preventing exacerbations of bronchiectasis
INTRODUCTION: Bronchiectasis is a long-term lung condition, with dilated bronchi, chronic inflammation, chronic infection and acute exacerbations. Recurrent exacerbations are associated with poorer clinical outcomes such as increased severity of lung disease, further exacerbations, hospitalisations, reduced quality of life and increased risk of death. Despite an increasing prevalence of bronchiectasis, there is a critical lack of high-quality studies into the disease and no treatments specifically approved for its treatment. This trial aims to establish whether inhaled dual bronchodilators (long acting beta agonist (LABA) and long acting muscarinic antagonist (LAMA)) taken as either a stand-alone therapy or in combination with inhaled corticosteroid (ICS) reduce the number of exacerbations of bronchiectasis requiring treatment with antibiotics during a 12 month treatment period. METHODS: This is a multicentre, pragmatic, double-blind, randomised controlled trial, incorporating an internal pilot and embedded economic evaluation. 600 adult patients (≥18 years) with CT confirmed bronchiectasis will be recruited and randomised to either inhaled dual therapy (LABA+LAMA), triple therapy (LABA+LAMA+ICS) or matched placebo, in a 2:2:1 ratio (respectively). The primary outcome is the number of protocol defined exacerbations requiring treatment with antibiotics during the 12 month treatment period. ETHICS AND DISSEMINATION: Favourable ethical opinion was received from the North East-Newcastle and North Tyneside 2 Research Ethics Committee (reference: 21/NE/0020). Results will be disseminated in peer-reviewed publications, at national and international conferences, in the NIHR Health Technology Assessments journal and to participants and the public (using lay language). TRIAL REGISTRATION NUMBER: ISRCTN15988757
Near Threshold K+K- Meson-Pair Production in Proton-Proton Collisions
The near threshold total cross section and angular distributions of K+K- pair
production via the reaction pp --> ppK+K- have been studied at an excess energy
of Q = 17 MeV using the COSY-11 facility at the cooler synchrotron COSY. The
obtained cross section as well as an upper limit at an excess energy of Q = 3
MeV represent the first measurements on the K+K- production in the region of
small excess energies where production via the channel pp --> pp Phi --> ppK+K-
is energetically forbidden. The possible influence of a resonant production via
intermediate scalar states f0(980) and a0(980) is discussed.Comment: 8 pages, 6 figures, replaced with revised version, accepted for
publication in Phys. Lett.
Energy Dependence of the Near-Threshold Total Cross-Section for the pp --> pp eta' Reaction
Total cross sections for the pp --> pp eta' reaction have been measured in
the excess energy range from Q = 1.53 MeV to Q = 23.64 MeV. The experiment has
been performed at the internal installation COSY-11 using a stochastically
cooled proton beam of the COoler SYnchrotron COSY and a hydrogen cluster
target. The determined energy dependence of the total cross section weakens the
hypothesis of the S-wave repulsive interaction between the eta' meson and the
proton. New data agree well with predictions based on the phase-space
distribution modified by the proton-proton final-state-interaction (FSI) only.Comment: 12 pages, 1 table, 4 figure
Uneven and combined development and unequal exchange: the second wind of neoliberal ‘free trade’?
With capitalist social relations emerging in a prior system of absolutist states in Europe, the outward expansion of capitalism through conditions of uneven and combined development became dependent on the existence of multiple political entities. States in turn are brought into relations of unequal exchange within the global economy. This article analyses the way in which current neoliberal ‘free trade’ policies are related to these fundamental capitalist dynamics, deepening further processes of uneven and combined development as well as unequal exchange
Interlocutions with passive revolution
© The Author(s) 2018. This article critically engages with debates on uneven and combined development and particularly the lack of attention given in this literature to accounts of spatial diversity in capitalism’s outward expansion as well as issues of Eurocentrism. Through interlocutions with Antonio Gramsci on his theorising of state formation and capitalist modernity and the notion of passive revolution, we draw out the internal relationship between the structuring condition of uneven and combined development and the class agency of passive revolution. Interlocuting with passive revolution places Antonio Gramsci firmly within a stream of classic social theory shaping considerations of capitalist modernity. As a result, by building on cognate theorising elsewhere, passive revolution can then be established as a lateral field of causality that necessarily grasps spatio-temporal dynamics linked to both state and subaltern class practices of transformation in social property relations, situated within the structuring conditions of uneven and combined development
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