15,336 research outputs found
The First Fermi-LAT SNR Catalog SNR and Cosmic Ray Implications
Galactic cosmic ray (CRs) sources, classically proposed to be Supernova
Remnants (SNRs), must meet the energetic particle content required by direct
measurements of high energy CRs. Indirect gamma-ray measurements of SNRs with
the Fermi Large Area Telescope (LAT) have now shown directly that at least
three SNRs accelerate protons. With the first Fermi LAT SNR Catalog, we have
systematically characterized the GeV gamma-rays emitted by 279 SNRs known
primarily from radio surveys. We present these sources in a multiwavelength
context, including studies of correlations between GeV and radio size, flux,
and index, TeV index, and age and environment tracers, in order to better
understand effects of evolution and environment on the GeV emission. We show
that previously sufficient models of SNRs' GeV emission no longer adequately
describe the data. To address the question of CR origins, we also examine the
SNRs' maximal CR contribution assuming the GeV emission arises solely from
proton interactions. Improved breadth and quality of multiwavelength data,
including distances and local densities, and more, higher resolution gamma-ray
data with correspondingly improved Galactic diffuse models will strengthen this
constraint.Comment: 8 pages, 10 figures; in Proceedings of the 34th International Cosmic
Ray Conference (ICRC 2015), The Hague (The Netherlands
Stability of quantum states of finite macroscopic systems against classical noises, perturbations from environments, and local measurements
We study the stability of quantum states of macroscopic systems of finite
volume V, against weak classical noises (WCNs), weak perturbations from
environments (WPEs), and local measurements (LMs). We say that a pure state is
`fragile' if its decoherence rate is anomalously great, and `stable against
LMs' if the result of a LM is not affected by another LM at a distant point. By
making full use of the locality and huge degrees of freedom, we show the
following: (i) If square fluctuation of every additive operator is O(V) or less
for a pure state, then it is not fragile in any WCNs or WPEs. (ii) If square
fluctuations of some additive operators are O(V^2) for a pure state, then it is
fragile in some WCNs or WPEs. (iii) If a state (pure or mixed) has the `cluster
property,' then it is stable against LMs, and vice versa. These results have
many applications, among which we discuss the mechanism of symmetry breaking in
finite systems.Comment: 6 pages, no figure.Proof of the theorem is described in the revised
manuscrip
CCD Washington photometry of four poorly studied open clusters in the two inner quadrants of the galactic plane
Complementing our Washington photometric studies on Galactic open clusters
(OCs), we now focus on four poorly studied OCs located in the first and fourth
Galactic quadrants, namely BH 84, NGC 5381, BH 211 and Czernik 37. We have
obtained CCD photometry in the Washington system and passbands down
to 18.5 magnitudes for these four clusters. Their positions and
sizes were determined using the stellar density radial profiles. We derived
reddening, distance, age and metallicity of the clusters from extracted
color-magnitude diagrams (CMDs), using theoretical isochrones
computed for the Washington system. There are no previous photometric data in
the optical band for BH 84, NGC 5381 and BH 211. The CMDs of the observed
clusters show relatively well defined main sequences, except for Czernik 37,
wherein significant differential reddening seems to be present. The red giant
clump is clearly seen only in BH 211. For this cluster, we estimated the age in
(1000) Myr, assuming a metallicity of = 0.019. BH 84 was
found to be much older than it was previously believed, while NGC 5381 happened
to be much younger than previously reported. The heliocentric distances to
these clusters are found to range between 1.4 and 3.4 kpc. BH 84 appears to be
located at the solar galactocentric distance, while NGC 5381, BH 211 and
Czernik 37 are situated inside the solar ring.Comment: 30 pages, 9 figures, 10 table
Cannabinoids in the treatment of epilepsy: current status and future prospects
Cannabidiol (CBD) is one of the prominent phytocannabinoids found in Cannabis sativa, differentiating from Δ9-tetrahydrocannabinol (THC) for its non-intoxicating profile and its antianxiety/antipsychotic effects. CBD is a multi-target drug whose anti-convulsant properties are supposed to be independent of endocannabinoid receptor CB1 and might be related to several underlying mechanisms, such as antagonism on the orphan GPR55 receptor, regulation of adenosine tone, activation of 5HT1A receptors and modulation of calcium intracellular levels. CBD is a lipophilic compound with low oral bioavailability (6%) due to poor intestinal absorption and high first-pass metabolism. Its exposure parameters are greatly influenced by feeding status (ie, high fatcontaining meals). It is mainly metabolized by cytochrome P 450 (CYP) 3A4 and 2C19, which it strongly inhibits. A proprietary formulation of highly purified, plant-derived CBD has been recently licensed as an adjunctive treatment for Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS), while it is being currently investigated in tuberous sclerosis complex. The regulatory agencies’ approval was granted based on four pivotal double-blind, placebocontrolled, randomized clinical trials (RCTs) on overall 154 DS patients and 396 LGS ones, receiving CBD 10 or 20 mg/kg/day BID as active treatment. The primary endpoint (reduction in monthly seizure frequency) was met by both CBD doses. Most patients reported adverse events (AEs), generally from mild to moderate and transient, which mainly consisted of somnolence, sedation, decreased appetite, diarrhea and elevation in aminotransferase levels, the last being documented only in subjects on concomitant valproate therapy. The interaction between CBD and clobazam, likely due to CYP2C19 inhibition, might contribute to some AEs, especially somnolence, but also to CBD clinical effectiveness. Cannabidivarin (CBDV), the propyl analogue of CBD, showed anti-convulsant properties in pre-clinical studies, but a plant-derived, purified proprietary formulation of CBDV recently failed the Phase II RCT in patients with uncontrolled focal seizures
Conserved spin and orbital phase along carbon nanotubes connected with multiple ferromagnetic contacts
We report on spin dependent transport measurements in carbon nanotubes based
multi-terminal circuits. We observe a gate-controlled spin signal in non-local
voltages and an anomalous conductance spin signal, which reveal that both the
spin and the orbital phase can be conserved along carbon nanotubes with
multiple ferromagnetic contacts. This paves the way for spintronics devices
exploiting both these quantum mechanical degrees of freedom on the same
footing.Comment: 8 pages - minor differences with published versio
Web-interface for geo-referencing forest economic valuation surveys
PosterIn New Zealand, 90% of forests consist of one type of exotic tree: Radiata pine (Pinus radiata).
A study on the management of such exotic planted forests in New Zealand for the conservation of threatened native animals and plants (e.g., kiwi, kakabeak) is undergoing and socio-economic questionnaires are an important tool to understand public views on the role of exotic forests for the native species.
In such questionnaires, is important to understand the relationship of the answers to landscape elements, either natural (e.g. mountain) or more artificial (e.g. buildings).
An online tool to geo-reference the answers has been developed to retrieve (and treat with confidentially) coordinates by the interviewed. The tool uses a mix of programming languages (HTML, Javascript, PHP, and Ajax) as well as the GoogleMaps© application programming interface to interact with the user to locate their living place.
The tool supplies the coordinates to the analysts which, through landscape metrics, will relate the qualitative importance given by certain answers to the proximity to certain elements in the landscape.
The tool (see link below) can be adapted to any survey that could consider the coordinates of the answers as an added value to the questionnaires analysis.
Link: http://home.isa.utl.pt/~joaopalma/surveys/nzfalco
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