1,558 research outputs found
Ultraluminous Infrared Galaxies
At luminosities above ~10^{11} L_sun, infrared galaxies become the dominant
population of extragalactic objects in the local Universe (z < 0.5), being more
numerous than optically selected starburst and Seyfert galaxies, and QSOs at
comparable bolometric luminosity. At the highest luminosities, ultraluminous
infrared galaxies (ULIGs: L_ir > 10^{12} L_sun), outnumber optically selected
QSOs by a factor of ~1.5-2. All of the nearest ULIGs (z < 0.1) appear to be
advanced mergers that are powered by both a circumnuclear starburst and AGN,
both of which are fueled by an enormous concentration of molecular gas
(~10^{10} M_sun) that has been funneled into the merger nucleus. ULIGs may
represent a primary stage in the formation of massive black holes and
elliptical galaxy cores. The intense circumnuclear starburst that accompanies
the ULIG phase may also represent a primary stage in the formation of globular
clusters, and the metal enrichment of the intergalactic medium by gas and dust
expelled from the nucleus due to the combined forces of supernova explosions
and powerful stellar winds.Comment: LaTex, 6 pages with 4 embedded .eps figures. Postscript version plus
color plates available at
http://www.ifa.hawaii.edu/users/sanders/astroph/s186/plates.html To appear in
"Galaxy Interactions at Low and High Redshift" IAU Symposium 186, Kyoto,
Japan, eds. J.E. Barnes and D.B. Sander
The Production of Antibody by Invading B Cells Is Required for the Clearance of Rabies Virus from the Central Nervous System
Every year over 50,000 people die from rabies worldwide, primarily due to the poor availability of rabies vaccine in developing countries. However, even when vaccines are available, human deaths from rabies occur if exposure to the causative virus is not recognized and vaccination is not sought in time. This is because rabies virus immunity induced by the natural infection or current vaccines is generally not effective at removing disease-causing rabies virus from brain tissues. Our studies provide insight into why this is the case and how vaccination can be changed so that the immune response can clear the virus from brain tissues. We show that the type of immune response induced by a live-attenuated rabies virus vaccine may be the key. In animal models, live-attenuated rabies virus vaccines are effective at delivering the immune cells capable of clearing the virus into CNS tissues and promote recovery from a rabies virus infection that has spread to the brain while conventional vaccines based on killed rabies virus do not. The production of rabies-specific antibody by B cells that invade the CNS tissues is important for complete elimination of the virus. We hypothesize that similar mechanisms may promote rabies virus clearance from individuals who are diagnosed after the virus has reached, but not extensively spread, through the CNS
Thalamic inputs to dorsomedial striatum are involved in inhibitory control: evidence from the five-choice serial reaction time task in rats
Rationale
Corticostriatal circuits are widely implicated in the top-down control of attention including inhibitory control and behavioural flexibility. However, recent neurophysiological evidence also suggests a role for thalamic inputs to striatum in behaviours related to salient, reward-paired cues.
Objectives
Here, we used designer receptors exclusively activated by designer drugs (DREADDs) to investigate the role of parafascicular (Pf) thalamic inputs to the dorsomedial striatum (DMS) using the five-choice serial reaction time task (5CSRTT) in rats.
Methods
The 5CSRTT requires sustained attention in order to detect spatially and temporally distributed visual cues and provides measures of inhibitory control related to impulsivity (premature responses) and compulsivity (perseverative responses). Rats underwent bilateral Pf injections of the DREADD vector, AAV2-CaMKIIa-HA-hM4D(Gi)-IRES-mCitrine. The DREADD agonist, clozapine N-oxide (CNO; 1 ÎŒl bilateral; 3 ÎŒM) or vehicle, was injected into DMS 1 h before behavioural testing. Task parameters were manipulated to increase attention load or reduce stimulus predictability respectively.
Results
We found that inhibition of the Pf-DMS projection significantly increased perseverative responses when stimulus predictability was reduced but had no effect on premature responses or response accuracy, even under increased attentional load. Control experiments showed no effects on locomotor activity in an open field.
Conclusions
These results complement previous lesion work in which the DMS and orbitofrontal cortex were similarly implicated in perseverative responses and suggest a specific role for thalamostriatal inputs in inhibitory control
Hydroxymethylglutaryl-CoA reductase inhibition with simvastatin in acute lung injury to reduce pulmonary dysfunction (HARP-2) trial : study protocol for a randomized controlled trial
Acute lung injury (ALI) is a common devastating clinical syndrome characterized by life-threatening respiratory failure requiring mechanical ventilation and multiple organ failure. There are in vitro, animal studies and pre-clinical data suggesting that statins may be beneficial in ALI. The Hydroxymethylglutaryl-CoA reductase inhibition with simvastatin in Acute lung injury to Reduce Pulmonary dysfunction (HARP-2) trial is a multicenter, prospective, randomized, allocation concealed, double-blind, placebo-controlled clinical trial which aims to test the hypothesis that treatment with simvastatin will improve clinical outcomes in patients with ALI
A smartphone intervention for adolescent obesity: study protocol for a randomised controlled non-inferiority trial
Background
There are few evidence-based mobile health solutions for treating adolescent obesity. The primary aim of this parallel non-inferiority trial is to assess the effectiveness of an experimental smartphone application in reducing obesity at 12 months, compared to the Temple Street W82GO Healthy Lifestyles intervention.
Methods/design
The primary outcome measure is change in body mass index standardised deviation score at 12 months. The secondary aim is to compare the effect of treatment on secondary outcomes, including waist circumference, insulin sensitivity, quality of life, physical activity and psychosocial health. Adolescents with a body mass index at or above the 98th percentile (12 to 17 years) will be recruited from the Obesity clinic at Temple Street Childrenâs University Hospital in Dublin, Ireland. W82GO is a family-based lifestyle change intervention delivered in two phases over 12 months. In the current study, participants will be randomised for phase two of treatment to either usual care or care delivered via smartphone application. One hundred and thirty-four participants will be randomised between the two study arms. An intention-to-treat analysis will be used to compare treatment differences between the groups at 12 months.
Discussion
The results of this study will be disseminated via open access publication and will provide important information for clinicians, patients and policy makers regarding the use of mobile health interventions in the management of adolescent obesity.
Trial registration
Clinicaltrials.gov NCT01804855
Gravito-electromagnetic analogies
We reexamine and further develop different gravito-electromagnetic (GEM)
analogies found in the literature, and clarify the connection between them.
Special emphasis is placed in two exact physical analogies: the analogy based
on inertial fields from the so-called "1+3 formalism", and the analogy based on
tidal tensors. Both are reformulated, extended and generalized. We write in
both formalisms the Maxwell and the full exact Einstein field equations with
sources, plus the algebraic Bianchi identities, which are cast as the
source-free equations for the gravitational field. New results within each
approach are unveiled. The well known analogy between linearized gravity and
electromagnetism in Lorentz frames is obtained as a limiting case of the exact
ones. The formal analogies between the Maxwell and Weyl tensors are also
discussed, and, together with insight from the other approaches, used to
physically interpret gravitational radiation. The precise conditions under
which a similarity between gravity and electromagnetism occurs are discussed,
and we conclude by summarizing the main outcome of each approach.Comment: 60 pages, 2 figures. Improved version (compared to v2) with some
re-write, notation improvements and a new figure that match the published
version; expanded compared to the published version to include Secs. 2.3 and
A review of physical supply and EROI of fossil fuels in China
This paper reviews Chinaâs future fossil fuel supply from the perspectives of physical output and net energy output. Comprehensive analyses of physical output of fossil fuels suggest that Chinaâs total oil production will likely reach its peak, at about 230Â Mt/year (or 9.6Â EJ/year), in 2018; its total gas production will peak at around 350Â Bcm/year (or 13.6Â EJ/year) in 2040, while coal production will peak at about 4400Â Mt/year (or 91.9Â EJ/year) around 2020 or so. In terms of the forecast production of these fuels, there are significant differences among current studies. These differences can be mainly explained by different ultimately recoverable resources assumptions, the nature of the models used, and differences in the historical production data. Due to the future constraints on fossil fuels production, a large gap is projected to grow between domestic supply and demand, which will need to be met by increasing imports. Net energy analyses show that both coal and oil and gas production show a steady declining trend of EROI (energy return on investment) due to the depletion of shallow-buried coal resources and conventional oil and gas resources, which is generally consistent with the approaching peaks of physical production of fossil fuels. The peaks of fossil fuels production, coupled with the decline in EROI ratios, are likely to challenge the sustainable development of Chinese society unless new abundant energy resources with high EROI values can be found
Advancing Tests of Relativistic Gravity via Laser Ranging to Phobos
Phobos Laser Ranging (PLR) is a concept for a space mission designed to
advance tests of relativistic gravity in the solar system. PLR's primary
objective is to measure the curvature of space around the Sun, represented by
the Eddington parameter , with an accuracy of two parts in ,
thereby improving today's best result by two orders of magnitude. Other mission
goals include measurements of the time-rate-of-change of the gravitational
constant, and of the gravitational inverse square law at 1.5 AU
distances--with up to two orders-of-magnitude improvement for each. The science
parameters will be estimated using laser ranging measurements of the distance
between an Earth station and an active laser transponder on Phobos capable of
reaching mm-level range resolution. A transponder on Phobos sending 0.25 mJ, 10
ps pulses at 1 kHz, and receiving asynchronous 1 kHz pulses from earth via a 12
cm aperture will permit links that even at maximum range will exceed a photon
per second. A total measurement precision of 50 ps demands a few hundred
photons to average to 1 mm (3.3 ps) range precision. Existing satellite laser
ranging (SLR) facilities--with appropriate augmentation--may be able to
participate in PLR. Since Phobos' orbital period is about 8 hours, each
observatory is guaranteed visibility of the Phobos instrument every Earth day.
Given the current technology readiness level, PLR could be started in 2011 for
launch in 2016 for 3 years of science operations. We discuss the PLR's science
objectives, instrument, and mission design. We also present the details of
science simulations performed to support the mission's primary objectives.Comment: 25 pages, 10 figures, 9 table
Anti-Allergic Cromones Inhibit Histamine and Eicosanoid Release from Activated Human and Murine Mast Cells by Releasing Annexin A1
PMCID: PMC3601088This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
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