4,591 research outputs found
Clinical and serologic responses to human âapathogenic' trypanosomes
We describe a female patient suffering from a benign self-healing febrile disease with strongly positive serology for Trypanosoma brucei. The patient showed a clinical picture with similarities to that of human African trypanosomiasis (HAT). HAT due to T. b. gambiense and T. b. rhodesiense were ruled out. We performed serologic tests because the patient was worried about HAT after receiving tsetse bites. The possibilities of an infection with human âapathogenic' trypanosomes such as T. b. brucei, T. congolense or T. vivax are discusse
Strange and singlet form factors of the nucleon: Predictions for G0, A4, and HAPPEX-II experiments
We investigate the strange and flavor-singlet electric and magnetic form
factors of the nucleon within the framework of the SU(3) chiral quark-soliton
model. Isospin symmetry is assumed and the symmetry-conserving SU(3)
quantization is employed, rotational and strange quark mass corrections being
included. For the experiments G0, A4, and HAPPEX-II we predict the quantities
and . The dependence
of the results on the parameters of the model and the treatment of the Yukawa
asymptotic behavior of the soliton are investigated.Comment: 16 pages, 3 figures, Final version for publication in Eur. Phys. J.
Q-Value and Half-Lives for the Double-Beta-Decay Nuclide 110Pd
The 110Pd double-beta decay Q-value was measured with the Penning-trap mass
spectrometer ISOLTRAP to be Q = 2017.85(64) keV. This value shifted by 14 keV
compared to the literature value and is 17 times more precise, resulting in new
phase-space factors for the two-neutrino and neutrinoless decay modes. In
addition a new set of the relevant matrix elements has been calculated. The
expected half-life of the two-neutrino mode was reevaluated as 1.5(6) E20 yr.
With its high natural abundance, the new results reveal 110Pd to be an
excellent candidate for double-beta decay studies
Microscopic description of cluster radioactivity in actinide nuclei
Cluster radioactivity is the emission of a fragment heavier than an α particle and lighter than mass 50. The range of clusters observed in experiments goes from 14C to 32Si while the heavy mass residue is always a nucleus in the neighborhood of the doubly-magic 208Pb nucleus. Cluster radioactivity is described in this paper as very asymmetric nuclear fission. A new fission valley leading to a decay with large fragment mass asymmetry matching the cluster radioactivity products is found. The mass octupole moment is found to be more convenient than the standard quadrupole moment as the parameter driving the system to fission. The mean-field Hartree-Fock-Bogoliubov theory with the phenomenological Gogny interaction has been used to compute the cluster emission properties of a wide range of even-even actinide nuclei from 222Ra to 242Cm, where emission of the clusters has been experimentally observed. Computed half-lives for cluster emission are compared with experimental results. The noticeable agreement obtained between the predicted properties of cluster emission (namely, cluster masses and emission half-lives) and the measured data confirms the validity of the proposed methodology in the analysis of the phenomenon of cluster radioactivity. A continuous fission path through the scission point has been described using the neck parameter constraintThe work of LMR was supported by Ministerio de Ciencia e Innovacion (Spain) Grants No. FPA2009-08958 and No. FIS2009-07277, as well as by Consolider-Ingenio 2010 Programs CPAN CSD2007-00042 and MULTIDARK CSD2009- 00064. The work of MW was supported by Ministerstwo Nauki i Szkolnictwa Wyzszego (Poland) under Grant No. N N202 23113
The near-infrared and ice-band variability of Haro 6-10
We have monitored the angularly resolved near infrared and 3.1 micron
ice-band flux of the components of the young binary Haro 6-10 on 23 occasions
during the years 1988 to 2000. Our observations reveal that both the visible
star Haro 6-10 (Haro 6-10S) and its infrared companion (Haro 6-10N) show
significant variation in flux on time scales as short as a month. The
substantial flux decrease of Haro 6-10S over the last four years carries the
reddening signature of increased extinction. However, a comparable K-band flux
increase observed in the IRC is associated with a dimming in the H-band and
cannot be explained by lower extinction. Absorption in the 3.1 micron water-ice
feature was always greater towards the IRC during our observations, indicating
a larger amount of obscuring material along its line of sight. We detect
variability in the ice-band absorption towards Haro 6-10S and Haro 6-10N,
significant at the 3.5 sigma and 2.0 sigma levels, respectively.Comment: 8 pages, 6 Figures, Accepted for Publication in Astronomy &
Astrophysic
The WITCH experiment: Acquiring the first recoil ion spectrum
The standard model of the electroweak interaction describes beta-decay in the
well-known V-A form. Nevertheless, the most general Hamiltonian of a beta-decay
includes also other possible interaction types, e.g. scalar (S) and tensor (T)
contributions, which are not fully ruled out yet experimentally. The WITCH
experiment aims to study a possible admixture of these exotic interaction types
in nuclear beta-decay by a precise measurement of the shape of the recoil ion
energy spectrum. The experimental set-up couples a double Penning trap system
and a retardation spectrometer. The set-up is installed in ISOLDE/CERN and was
recently shown to be fully operational. The current status of the experiment is
presented together with the data acquired during the 2006 campaign, showing the
first recoil ion energy spectrum obtained. The data taking procedure and
corresponding data acquisition system are described in more detail. Several
further technical improvements are briefly reviewed.Comment: 11 pages, 6 figures, conference proceedings EMIS 2007
(http://emis2007.ganil.fr), published also in NIM B:
doi:10.1016/j.nimb.2008.05.15
Large-scale magnetized outflows from the Virgo Cluster spiral NGC 4569 : a galactic wind in a ram pressure wind
Using the Effelsberg radio telescope at 4.85Â GHz and 8.35Â GHz we
discovered large symmetric lobes of polarized radio emission around the
strongly H
CXCR-4 expression by circulating endothelial progenitor cells and SDF-1 serum levels are elevated in septic patients
Background: Endothelial progenitor cell (EPC) numbers are increased in septic patients and correlate with survival. In this study, we investigated, whether surface expression of chemokine receptors and other receptors important for EPC homing is upregulated by EPC from septic patients and if this is associated with clinical outcome.
Methods: Peripheral blood mononuclear cells from septic patients (n =â30), ICU control patients (n =â11) and healthy volunteers (n =â15) were isolated by Ficoll density gradient centrifugation. FACS-analysis was used to measure the expression of the CXC motif chemokine receptors (CXCR)-2 andâââ4, the receptor for advanced glycation endproducts (RAGE) and the stem cell factor receptor c-Kit. Disease severity was assessed via the Simplified Acute Physiology Score (SAPS) II. The serum concentrations of vascular endothelial growth factor (VEGF), stromal cell-derived factor (SDF)-1α and angiopoietin (Ang)-2 were determined with Enzyme linked Immunosorbent Assays.
Results: EPC from septic patients expressed significantly more CXCR-4, c-Kit and RAGE compared to controls and were associated with survival-probability. Significantly higher serum concentrations of VEGF, SDF-1α and Ang-2 were found in septic patients. SDF-1α showed a significant association with survival.
Conclusions: Our data suggest that SDF-1α and CXCR-4 signaling could play a crucial role in EPC homing in the course of sepsis
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