1,036 research outputs found
The Poker Face of Inelastic Dark Matter: Prospects at Upcoming Direct Detection Experiments
The XENON100 and CRESST experiments will directly test the inelastic dark
matter explanation for DAMA's 8.9? sigma anomaly. This article discusses how
predictions for direct detection experiments depend on uncertainties in
quenching factor measurements, the dark matter interaction with the Standard
Model and the halo velocity distribution. When these uncertainties are
accounted for, an order of magnitude variation is found in the number of
expected events at CRESST and XENON100.Comment: 5 pages, 3 figure
Direct Detection of Dark Matter Debris Flows
Tidal stripping of dark matter from subhalos falling into the Milky Way
produces narrow, cold tidal streams as well as more spatially extended "debris
flows" in the form of shells, sheets, and plumes. Here we focus on the debris
flow in the Via Lactea II simulation, and show that this incompletely
phase-mixed material exhibits distinctive high velocity behavior. Unlike tidal
streams, which may not necessarily intersect the Earth's location, debris flow
is spatially uniform at 8 kpc and thus guaranteed to be present in the dark
matter flux incident on direct detection experiments. At Earth-frame speeds
greater than 450 km/s, debris flow comprises more than half of the dark matter
at the Sun's location, and up to 80% at even higher speeds. Therefore, debris
flow is most important for experiments that are particularly sensitive to the
high speed tail of the dark matter distribution, such as searches for light or
inelastic dark matter or experiments with directional sensitivity. We show that
debris flow yields a distinctive recoil energy spectrum and a broadening of the
distribution of incidence direction.Comment: 22 pages, 7 figures; accepted for publication in PR
High Multiplicity Searches at the LHC Using Jet Masses
This article introduces a new class of searches for physics beyond the
Standard Model that improves the sensitivity to signals with high jet
multiplicity. The proposed searches gain access to high multiplicity signals by
reclustering events into large-radius, or "fat," jets and by requiring that
each event has multiple massive jets. This technique is applied to
supersymmetric scenarios in which gluinos are pair-produced and then
subsequently decay to final states with either moderate quantities of missing
energy or final states without missing energy. In each of these scenarios, the
use of jet mass improves the estimated reach in gluino mass by 20 % to 50 %
over current LHC searches.Comment: 9 pages, 6 figures; v3 corrects a few small typo
Cytotoxicity of the urokinase-plasminogen activator inhibitor carbamimidothioic acid (4-boronophenyl) methyl ester hydrobromide (BC-11) on triple-negative MDA-MB231 breast cancer cells
Abstract: BC-11 is an easily synthesized simple thiouronium-substituted phenylboronic acid, which has been shown to be cytotoxic on triple negative MDA-MB231 breast cancer cells by inducing a perturbation of cell cycle when administered at a concentration equal to its ED50 at 72 h (117 μM). Exposure of cells to BC-11, either pre-absorbed with a soluble preparation of the N-terminal fragment of urokinase-plasminogen activator (uPa), or in co-treatment with two different EGFR inhibitors, indicated that: (i) BC-11 acts via binding to the N-terminus of the enzyme where uPa- and EGF receptor-recognizing sites are present, thereby abrogating the growth-sustaining effect resulting from receptor binding; and (ii) the co-presence of the EGFR inhibitor PD153035 potentiates BC-11’s cytotoxicity. Exposure of cells to a higher concentration of BC-11 corresponding to its ED75 at 72 h (250 μM) caused additional impairment of mitochondrial activity, the production of reactive oxygen species and promotion of apoptosis. Therefore, BC-11 treatment appears to show potential for the development of this class of compounds in the prevention and/or therapy of “aggressive” breast carcinoma
The Dark Matter at the End of the Galaxy
Dark matter density profiles based upon Lambda-CDM cosmology motivate an
ansatz velocity distribution function with fewer high velocity particles than
the Maxwell-Boltzmann distribution or proposed variants. The high velocity tail
of the distribution is determined by the outer slope of the dark matter halo,
the large radius behavior of the Galactic dark matter density. N-body
simulations of Galactic halos reproduce the high velocity behavior of this
ansatz. Predictions for direct detection rates are dramatically affected for
models where the threshold scattering velocity is within 30% of the escape
velocity.Comment: 10 pages, 5 figure
Using statistical analyses for improving rating methods for groundwater vulnerability in contamination maps
With the aim of developing procedures coping with the disadvantages and emphasising the advantages of existing rating methods and the use of statistical methods for assessing groundwater vulnerability, we propose to combine the two approaches to perform a groundwater vulnerability assessment in a study area in Italy. In the case study, located in an area of northern Italy with both urban and agricultural sectors, keeping the structure of the DRASTIC rating method, we used a spatial statistical approach to calibrate weights and ratings of a series of variables, potentially affecting groundwater vulnerability. In order to verify the effectiveness of these procedures, the results were compared to a non-modified approach and to the map resulting from the ‘‘Time–Input’’ method, highlighting the advantages that can be obtained, and defining the general limit of these applications. The revised method shows a more realistic distribution of vulnerability classes in accordance with the distribution of wells impacted by high nitrate concentration, demonstrating the importance of taking into account the specific hydrogeological conditions of the area
Synthesis of hybrid anticancer agents based on kinase and histone deacetylase inhibitors
Fragments based on the VEGFR2i Semaxanib (SU5416, (vascular endothelial growth factor receptor-2
inhibitor) and the HDACi (histone deacetylase inhibitor) SAHA (suberanilohydroxamic acid) have been
merged to form a range of low molecular weight dual action hybrids. Vindication of this approach is
provided by SAR, docking studies, in vitro cancer cell line and biochemical enzyme inhibition data as well
as in vivo Xenopus data for the lead molecule (Z)-N1-(3-((1H-pyrrol-2-yl)methylene)-2-oxoindolin-5-yl)-
N8-hydroxyoctanediamide 6
Microsatellite polymorphism in tsetse flies (Diptera: Glossinidae).
In sub-Saharan Africa, tsetse flies are the vectors of trypanosomes, the causative agents of sleeping sickness in humans and nagana in animals. Certain wild populations of the palpalis group exhibit intraspecific variation and are suspect of manifest differences in vectorial capacity. The current study reports the identification of 13 polymorphic microsatellite loci from Glossina palpalis palpalis Robinean-Desvoidy. The majority of these markers amplify corresponding loci from the related species C. p. gambiensis Vanderplank, G. f. fuscipes Newstead, and G. tachinoides Westwood. Only seven of 13 loci were amplified from G. austeni Newstead. Genetic variability was estimated in one field population of G. p. gambiensis. These results confirmed that microsatellite markers may be used to examine the subpopulation structure of tsetse flies
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