4,789 research outputs found
Studying the coincidence excess between EXPLORER and NAUTILUS during 1998
The coincidences between EXPLORER and NAUTILUS during 1998 (Astone et al.
2001) are more deeply studied. It is found that the coincidence excess is
greater in the ten-day period 7-17 September 1998 and it occurs at the sidereal
hour 4, when the detectors axes are perpendicular to the Galactic Disk. The
purpose of this paper is to bring our results with the GW detectors to the
attention of scientists working in the astrophysical field, and ask them
whether are they aware of any special phenomenon occurring when EXPLORER and
NAUTILUS showed a coincidence excess.Comment: 5 pages, 7 figures, submitted to A &
Asymptotics of the Packet Speed and Cost in a Mobile Wireless Network Model
An infinite number of nodes move on R^2 according
to a random waypoint model; a single packet is traveling
towards a destination (located at an infinite distance away) using
combinations of wireless transmissions and physical transport
on the buffers of nodes. In earlier work [1] we defined two
performance metrics, namely, the long-term average speed with
which the packet travels towards its destination, and the rate
with which transmission cost accumulates with distance covered.
Analytical expressions were derived for these metrics, under
specific ergodicity assumptions. In this paper we give a precise
description of the induced Markov process, we show that it is
indeed (uniformly) geometrically ergodic, and that the law of
large numbers holds for the random variables of interest. In
particular, we show that the two performance metrics are well-
defined and asymptotically constant with probability one.European Union’s
Horizon 2020 Research and Innovation programme under
grant agreement No. 645220 (Road-, Air- and Water-based
Future Internet Experimentation - RAWFIE)
High genetic diversity within and among bitter cassava cultivated in three soil types in Central Amazonia.
Bitter cassava is an important food crop that was domesticated in Amazonia. Although it is exclusively propagated by stem cuttings, cassava retained its ability of sexual reproduction. The occurrence and incorporation of sexual plants into the stock of clonal varieties contributes to the high genetic diversity observed within the crop. Despite being well adapted to nutrient deprived soils of Amazonia, ethnobotanical observations showed that communities of smallholder farmers along the middle Madeira River, in Central Amazonia, also cultivate cassava in the highly fertile soils of the floodplains and Amazonian dark earths (ADE). These farmers grow different sets of varieties in each soil type, which may also contribute to the maintenance of high levels of genetic diversity within the crop. We evaluated with 10 nuclear microsatellite markers the genetic diversity within and among some of the most commonly cultivated bitter cassava varieties grown on ADE, floodplain and Oxisols soils in the middle Madeira region. High levels of genetic diversity within varieties were observed (HO ranging from 0.495 to 0.707, and HE ranging from 0.250 to 0.460). Additionally, varieties were generally highly differentiated from each other. Although high levels of genetic diversity were previously observed in studies carried out in regions of low soil fertility in other parts of Amazonia, we identified that management of different soil types is important to the maintenance of genetically distinct stocks of varieties, which also contributes to the maintenance of the genetic diversity within the crop
Antiviral activity of fecal water samples from HIV-1 infected subjects treated with a specific probiotic formulation
Objectives: The aim of the study was to investigate if the supplementation with multistrain probiotics may be able to modulate T cell response in HIV-1 infected patients and to evaluate the anti-HIV activity of probiotic by studying fecal water (FW) samples. Methods: Three HIV-1-positive patients (Pt1, Pt2 and Pt3) on long-term suppressive combined antiretroviral therapy (cART) received a specific multi-strain probiotic supplementation (Vivomixx ®), for six months (T6). Levels of T cell subsets were evaluated by flow cytometry. Anti- HIV activity of FW samples was evaluated in vitro. Results: CD4+ T cells levels increased in all HIV-1 infected patients whereas activation markers (CD38 and HLA-DR) were decreased both on CD4+ and CD8+ T cells. FW samples presented an increased inhibitory activity against HIV-1 compared to T0 (FW-Pt1: T0 =40%, T6 = 65% of reduction; FW Pt2: T0 = 26%, T6 = 46% of reduction; FW Pt3: T0 = 47%, T6 = 94% of reduction). Discussion: Our data suggest that the administration of the specific probiotic formulation improves the antiviral status of people living with HIV-1 under cART, also modulating T cell response. Conclusion: Anti-HIV activity of FW may have several public health and social implications for sexually transmitted diseases that need to be further explored
Increasing the bandwidth of resonant gravitational antennas: The case of Explorer
Resonant gravitational wave detectors with an observation bandwidth of tens
of hertz are a reality: the antenna Explorer, operated at CERN by the ROG
collaboration, has been upgraded with a new read-out. In this new
configuration, it exhibits an unprecedented useful bandwidth: in over 55 Hz
about its frequency of operation of 919 Hz the spectral sensitivity is better
than 10^{-20} /sqrt(Hz) . We describe the detector and its sensitivity and
discuss the foreseable upgrades to even larger bandwidths.Comment: 4 pages- 4 figures Acceted for publication on Physical Review Letter
Study of the coincidences between the gravitational wave detectors EXPLORER and NAUTILUS in 2001
We report the result from a search for bursts of gravitational waves using
data collected by the cryogenic resonant detectors EXPLORER and NAUTILUS during
the year 2001, for a total measuring time of 90 days. With these data we
repeated the coincidence search performed on the 1998 data (which showed a
small coincidence excess) applying data analysis algorithms based on known
physical characteristics of the detectors. With the 2001 data a new interesting
coincidence excess is found when the detectors are favorably oriented with
respect to the Galactic Disk
Performance of a Tungsten-Cerium Fluoride Sampling Calorimeter in High-Energy Electron Beam Tests
A prototype for a sampling calorimeter made out of cerium fluoride crystals
interleaved with tungsten plates, and read out by wavelength-shifting fibres,
has been exposed to beams of electrons with energies between 20 and 150 GeV,
produced by the CERN Super Proton Synchrotron accelerator complex. The
performance of the prototype is presented and compared to that of a Geant4
simulation of the apparatus. Particular emphasis is given to the response
uniformity across the channel front face, and to the prototype's energy
resolution.Comment: 6 pages, 6 figures, Submitted to NIM
Microstructural Changes in the Striatum and Their Impact on Motor and Neuropsychological Performance in Patients with Multiple Sclerosis
Grey matter (GM) damage is a clinically relevant feature of multiple sclerosis (MS) that has been previously assessed with diffusion tensor imaging (DTI). Fractional anisotropy (FA) of the basal ganglia and thalamus might be increased in MS patients, and correlates with disability scores. Despite the established role of the striatum and thalamus in motor control, mood and cognition, the impact of DTI changes within these structures on motor and neuropsychological performance has not yet been specifically addressed in MS. We investigated DTI metrics of deep GM nuclei and their potential association with mobility and neuropsychological function. DTI metrics from 3T MRI were assessed in the caudate, putamen, and thalamus of 30 MS patients and 10 controls. Sixteen of the patients underwent neuropsychological testing. FA of the caudate and putamen was higher in MS patients compared to controls. Caudate FA correlated with Expanded Disability Status Scale score, Ambulation Index, and severity of depressive symptomatology. Putamen and thalamus FA correlated with deficits in memory tests. In contrast, cerebral white matter (WM) lesion burden showed no significant correlation with any of the disability, mobility and psychometric parameters. Our findings support evidence of FA changes in the basal ganglia in MS patients, as well as deep GM involvement in disabling features of MS, including mobility and cognitive impairment. Deep GM FA appears to be a more sensitive correlate of disability than WM lesion burden
Comparison of the Genetic Organization, Expression Strategies and Oncogenic Potential of HTLV-1 and HTLV-2
Human T cell leukemia virus types 1 and 2 (HTLV-1 and HTLV-2) are genetically related complex retroviruses that are capableof immortalizing human T-cells in vitro and establish life-long persistent infections in vivo. In spite of these apparent similarities,HTLV-1 and HTLV-2 exhibit a significantly different pathogenic potential. HTLV-1 is recognized as the causative agent of adult Tcell eukemia/lymphoma (ATLL) and tropical spastic paraparesis/HTLV-1-associatedmyelopathy (TSP/HAM). In contrast,HTLV- 2 has not been causally linked to human malignancy, although it may increase the risk of developing inflammatory neuropathies and infectious diseases. The present paper is focused on the studies aimed at defining the viral genetic determinants of the pathobiology of HTLV-1 and HTLV-2 through a comparison of the expression strategies and functional properties of the different gene products of the two viruses
Permanent water swelling effect in low temperature thermally reduced graphene oxide
We demonstrate permanent water trapping in reduced graphene oxide after high relative humidity exposure. For this purpose, we grew graphene oxide films via spin-coating on glass substrates followed by thermal reduction. The electrical resistance of the planar device was then measured. We observed that resistance is significantly increased after water vapor exposure and remains stable even after 250 days in ambient conditions. Various techniques were applied to desorb the water and decrease (recover) the material's resistance, but it was achieved only with low temperature thermal annealing (180 °C) under forming gas (H2/N2 mixture). The permanent effect of water absorption was also detected by x-ray photoelectron spectroscopy.</p
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