11,595 research outputs found
Mycobacteria-induced anaemia revisited : a molecular approach reveals the involvement of NRAMP1 and lipocalin-2, but not of hepcidin
Anaemia is a frequent complication of chronic infectious diseases but the exact mechanisms by which it develops remain to be clarified. In the present work, we used a mouse model of mycobacterial infection to study molecular alterations of iron metabolism induced by infection. We show that four weeks after infection with Mycobacterium avium BALB/c mice exhibited a moderate anaemia, which was not accompanied by an increase on hepatic hepcidin mRNA expression. Instead, infected mice presented increased mRNA expression of ferroportin (Slc40a1), ceruloplasmin (Cp), hemopexin (Hpx), heme-oxygenase-1 (Hmox1) and lipocalin-2 (Lcn2). Both the anaemia and the mRNA expression changes of iron-related genes were largely absent in C.D2 mice which bear a functional allele of the Nramp1 gene. Data presented in this work suggest that anaemia due to a chronic mycobacterial infection may develop in the absence of elevated hepcidin expression, is influenced by Nramp1 and may involve lipocalin-2.This work was supported by the EEC Framework 6 (LSHM-CT-2006037296 EuroIron1) and FCT-approved grant
POCTI/MGI/40132/2001, funded by FEDER.
Sandro Gomes was supported by FCT PhD grant SFRH/BD/29257/2006
Reproductive parameters and the use of MOET in transgenic founder goat carrying the human granulocyte colony-stimulating factor (hG-CSF) gene.
Abstract: This study aimed to monitor estrous cycle parameters of a human granulocyte colony-stimulating factor (hG-CSF)-transgenic founder female goat and to perform superovulation and embryo recovery (surgical or transcervical method) for further transfer to recipients to quickly obtain offspring. Two experiments were performed using a transgenic (TF) and a non-transgenic (NTF) female. In experiment 1, three estrous cycles were monitored for the following parameters: estrus behavior, progesterone concentration and ovarian activity. In experiment 2, two superovulation/embryo recovery sessions were performed and the recovered embryos were transferred to previously prepared recipients. Data were compared by either t test or Fisher's exact test. The mean interval between natural estrus was 20.7 ± 0.6 and 19.7 ± 0.6 (P > 0.05) days for the TF and NTF, respectively. Progesterone concentrations and ovarian activity were normal and similar between goats. The ovulation rate was similar between TF and NTF (12.0 ± 1.4 vs. 18.0 ± 4.2 CL; P > 0.05). No significant differences in embryo recovery rate (P > 0.05) were observed between the surgical and transcervical methods for TF (69.2 vs. 72.7%) or NTF (100.0 vs. 86.7%). Sixteen embryos from the TF were transferred to recipients, and eight kids were born. Among these kids, the transgene was identified in three (two males and one female), resulting in a transgenesis rate of 37.5%. In summary, the TF is a true founder, since she proved fertility and capacity of transmitting the hG-CSF transgene to progeny, suggesting that the analyzed reproductive traits were not compromised by the presence of the transgene
Subwavelength metamaterial for communications and sensing
Silicon photonics is considered a breakthrough technology with strong impact in areas as diverse as data center interconnection, high performance computing, the deployment of 5G future communication systems or lab-on-a-chip sensors. The emergence of sub-wavelength grating waveguides (SWG) has been fundamental to achieve advanced devices with unprecedented performance in integrated optics. In this talk we will focus on our recent progress in designing sub-wavelength engineered devices like ultra-broadband mode (de)multiplexers and converters [1], ultra-narrowband Bragg filters [2], sensing waveguides with enhanced sensitivity [3], or suspended silicon mid-infrared waveguides capable of covering the full transparency window of silicon [4], among other.
This work was supported by the Ministerio de Economía y Competitividad, Programa Estatal de Investigación, Desarrollo e Innovación Orientada a los Retos de la Sociedad (Proyecto TEC2016-80718-R), and the Universidad de Málaga (Campus de Excelencia Internacional Andalucía Tech).Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tech
Nuclear astrophysics with radioactive ions at FAIR
R. Reifarth et al: ; 12 págs.; 9 figs.; Open Access funded by Creative Commons Atribution Licence 3.0 ; Nuclear Physics in Astrophysics VI (NPA6)The nucleosynthesis of elements beyond iron is dominated by neutron captures
in the s and r processes. However, 32 stable, proton-rich isotopes cannot be formed during
those processes, because they are shielded from the s-process
ow and r-process -decay chains.
These nuclei are attributed to the p and rp process.
For all those processes, current research in nuclear astrophysics addresses the need for more
precise reaction data involving radioactive isotopes. Depending on the particular reaction, direct
or inverse kinematics, forward or time-reversed direction are investigated to determine or at least
to constrain the desired reaction cross sections.
The Facility for Antiproton and Ion Research (FAIR) will oer unique, unprecedented
opportunities to investigate many of the important reactions. The high yield of radioactive
isotopes, even far away from the valley of stability, allows the investigation of isotopes involved
in processes as exotic as the r or rp processes.This project was supported by the HGF Young Investigators Project VH-NG-327, EMMI, H4F,
HGS-HIRe, JINA, NAVI, DFG and ATHENA.Peer Reviewe
Measurement of the ratio of branching fractions BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma)
The ratio of branching fractions of the radiative B decays B0 -> K*0 gamma
and Bs0 -> phi gamma has been measured using 0.37 fb-1 of pp collisions at a
centre of mass energy of sqrt(s) = 7 TeV, collected by the LHCb experiment. The
value obtained is BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma) = 1.12 +/- 0.08
^{+0.06}_{-0.04} ^{+0.09}_{-0.08}, where the first uncertainty is statistical,
the second systematic and the third is associated to the ratio of fragmentation
fractions fs/fd. Using the world average for BR(B0 -> K*0 gamma) = (4.33 +/-
0.15) x 10^{-5}, the branching fraction BR(Bs0 -> phi gamma) is measured to be
(3.9 +/- 0.5) x 10^{-5}, which is the most precise measurement to date.Comment: 15 pages, 1 figure, 2 table
Integrating transposable elements in the 3D genome
Chromosome organisation is increasingly recognised as an essential component of genome regulation, cell fate and cell health. Within the realm of transposable elements (TEs) however, the spatial information of how genomes are folded is still only rarely integrated in experimental studies or accounted for in modelling. Whilst polymer physics is recognised as an important tool to understand the mechanisms of genome folding, in this commentary we discuss its potential applicability to aspects of TE biology. Based on recent works on the relationship between genome organisation and TE integration, we argue that existing polymer models may be extended to create a predictive framework for the study of TE integration patterns. We suggest that these models may offer orthogonal and generic insights into the integration profiles (or "topography") of TEs across organisms. In addition, we provide simple polymer physics arguments and preliminary molecular dynamics simulations of TEs inserting into heterogeneously flexible polymers. By considering this simple model, we show how polymer folding and local flexibility may generically affect TE integration patterns. The preliminary discussion reported in this commentary is aimed to lay the foundations for a large-scale analysis of TE integration dynamics and topography as a function of the three-dimensional host genome
Multi-particle azimuthal correlations in p-Pb and Pb-Pb collisions at the CERN Large Hadron Collider
Measurements of multi-particle azimuthal correlations (cumulants) for charged
particles in p-Pb and Pb-Pb collisions are presented. They help address the
question of whether there is evidence for global, flow-like, azimuthal
correlations in the p-Pb system. Comparisons are made to measurements from the
larger Pb-Pb system, where such evidence is established. In particular, the
second harmonic two-particle cumulants are found to decrease with multiplicity,
characteristic of a dominance of few-particle correlations in p-Pb collisions.
However, when a gap is placed to suppress such correlations,
the two-particle cumulants begin to rise at high-multiplicity, indicating the
presence of global azimuthal correlations. The Pb-Pb values are higher than the
p-Pb values at similar multiplicities. In both systems, the second harmonic
four-particle cumulants exhibit a transition from positive to negative values
when the multiplicity increases. The negative values allow for a measurement of
to be made, which is found to be higher in Pb-Pb collisions at
similar multiplicities. The second harmonic six-particle cumulants are also
found to be higher in Pb-Pb collisions. In Pb-Pb collisions, we generally find
which is indicative of a Bessel-Gaussian
function for the distribution. For very high-multiplicity Pb-Pb
collisions, we observe that the four- and six-particle cumulants become
consistent with 0. Finally, third harmonic two-particle cumulants in p-Pb and
Pb-Pb are measured. These are found to be similar for overlapping
multiplicities, when a gap is placed.Comment: 25 pages, 11 captioned figures, 3 tables, authors from page 20,
published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/87
Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at = 5.02 TeV
Two-particle angular correlations between unidentified charged trigger and
associated particles are measured by the ALICE detector in p-Pb collisions at a
nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum
range 0.7 5.0 GeV/ is examined,
to include correlations induced by jets originating from low
momen\-tum-transfer scatterings (minijets). The correlations expressed as
associated yield per trigger particle are obtained in the pseudorapidity range
. The near-side long-range pseudorapidity correlations observed in
high-multiplicity p-Pb collisions are subtracted from both near-side
short-range and away-side correlations in order to remove the non-jet-like
components. The yields in the jet-like peaks are found to be invariant with
event multiplicity with the exception of events with low multiplicity. This
invariance is consistent with the particles being produced via the incoherent
fragmentation of multiple parton--parton scatterings, while the yield related
to the previously observed ridge structures is not jet-related. The number of
uncorrelated sources of particle production is found to increase linearly with
multiplicity, suggesting no saturation of the number of multi-parton
interactions even in the highest multiplicity p-Pb collisions. Further, the
number scales in the intermediate multiplicity region with the number of binary
nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/161
Charge separation relative to the reaction plane in Pb-Pb collisions at TeV
Measurements of charge dependent azimuthal correlations with the ALICE
detector at the LHC are reported for Pb-Pb collisions at TeV. Two- and three-particle charge-dependent azimuthal correlations in
the pseudo-rapidity range are presented as a function of the
collision centrality, particle separation in pseudo-rapidity, and transverse
momentum. A clear signal compatible with a charge-dependent separation relative
to the reaction plane is observed, which shows little or no collision energy
dependence when compared to measurements at RHIC energies. This provides a new
insight for understanding the nature of the charge dependent azimuthal
correlations observed at RHIC and LHC energies.Comment: 12 pages, 3 captioned figures, authors from page 2 to 6, published
version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/286
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