1,070 research outputs found
Transcriptome profiling of gene expression during immunisation trial against Fasciola hepatica : Identification of genes and pathways involved in conferring immunoprotection in a murine model
Background: Fasciolosis remains a significant food-borne trematode disease causing high morbidity around the world and affecting grazing animals and humans. A deeper understanding concerning the molecular mechanisms by which Fasciola hepatica infection occurs, as well as the molecular basis involved in acquiring protection is extremely important when designing and selecting new vaccine candidates. The present study provides a first report of microarray-based technology for describing changes in the splenic gene expression profile for mice immunised with a highly effective, protection-inducing, multi-epitope, subunit-based, chemically-synthesised vaccine candidate against F. hepatica. Methods: The mice were immunised with synthetic peptides containing B- and T-cell epitopes, which are derived from F. hepatica cathepsin B and amoebapore proteins, as novel vaccine candidates against F. hepatica formulated in an adjuvant adaptation vaccination system; they were experimentally challenged with F. hepatica metacercariae. Spleen RNA from mice immunised with the highest protection-inducing synthetic peptides was isolated, amplified and labelled using Affymetrix standardised protocols. Data was then background corrected, normalised and the expression signal was calculated. The Ingenuity Pathway Analysis tool was then used for analysing differentially expressed gene identifiers for annotating bio-functions and constructing and visualising molecular interaction networks. Results: Mice immunised with a combination of three peptides containing T-cell epitopes induced high protection against experimental challenge according to survival rates and hepatic damage scores. It also induced differential expression of 820 genes, 168 genes being up-regulated and 652 genes being down-regulated, p value <0.05, fold change ranging from -2.944 to 7.632. A functional study of these genes revealed changes in the pathways related to nitric oxide and reactive oxygen species production, Interleukin-12 signalling and production in macrophages and Interleukin-8 signalling with up-regulation of S100 calcium-binding protein A8, Matrix metallopeptidase 9 and CXC chemokine receptor 2 genes. Conclusion: The data obtained in the present study provided us with a more comprehensive overview concerning the possible molecular pathways implied in inducing protection against F. hepatica in a murine model, which could be useful for evaluating future vaccine candidates. © 2017 The Author(s)
Remasking of Candida albicans β-Glucan in Response to Environmental pH Is Regulated by Quorum Sensing
Candida albicans is a commensal yeast of the human gut which is tolerated by the immune system but has the potential to become an opportunistic pathogen. One way in which C. albicans achieves this duality is through concealing or exposing cell wall pathogen-associated molecular patterns (PAMPs) in response to host-derived environment cues (pH, hypoxia, and lactate). This cell wall remodeling allows C. albicans to evade or hyperactivate the host’s innate immune responses, leading to disease. Previously, we showed that adaptation of C. albicans to acidic environments, conditions encountered during colonization of the female reproductive tract, induces significant cell wall remodeling resulting in the exposure of two key fungal PAMPs (β-glucan and chitin). Here, we report that this pH-dependent cell wall remodeling is time dependent, with the initial change in pH driving cell wall unmasking, which is then remasked at later time points. Remasking of β-glucan was mediated via the cell density-dependent fungal quorum sensing molecule farnesol, while chitin remasking was mediated via a small, heat-stable, nonproteinaceous secreted molecule(s). Transcript profiling identified a core set of 42 genes significantly regulated by pH over time and identified the transcription factor Efg1 as a regulator of chitin exposure through regulation of CHT2. This dynamic cell wall remodeling influenced innate immune recognition of C. albicans, suggesting that during infection, C. albicans can manipulate the host innate immune responses
Thermal neutron background at Laboratorio Subterráneo de Canfranc (LSC)
The thermal neutron background at Laboratorio Subterráneo de Canfranc (LSC) has been determined using several He proportional counter detectors. Bare and Cd shielded counters were used in a series of long measurements. Pulse shape discrimination techniques were applied to discriminate between neutron and gamma signals as well as other intrinsic contributions. Montecarlo simulations allowed us to estimate the sensitivity of the detectors and calculate values for the background flux of thermal neutrons inside Hall-A of LSC. The obtained value is (3.5±0.8)×10 n/cms, and is within an order of magnitude compared to similar facilities.This work was supported partially by the Spanish Ministerio de
Ciencia e InnovaciĂłn and its Plan Nacional de I+D+i de FĂsica de
PartĂculas projects: FPA2016-76765-P and FPA2018-096717-B-C21.
The authors want to acknowledge the help provided by the staff at LSC
in the preparation and support for this work
Bar pattern speeds in CALIFA galaxies: I. Fast bars across the Hubble sequence
The bar pattern speed () is defined as the rotational
frequency of the bar, and it determines the bar dynamics. Several methods have
been proposed for measuring . The non-parametric method
proposed by Tremaine \& Weinberg (1984; TW) and based on stellar kinematics is
the most accurate. This method has been applied so far to 17 galaxies, most of
them SB0 and SBa types. We have applied the TW method to a new sample of 15
strong and bright barred galaxies, spanning a wide range of morphological types
from SB0 to SBbc. Combining our analysis with previous studies, we investigate
32 barred galaxies with their pattern speed measured by the TW method. The
resulting total sample of barred galaxies allows us to study the dependence of
on galaxy properties, such as the Hubble type. We measured
using the TW method on the stellar velocity maps provided by
the integral-field spectroscopy data from the CALIFA survey. Integral-field
data solve the problems that long-slit data present when applying the TW
method, resulting in the determination of more accurate . In
addition, we have also derived the ratio of the corotation radius to
the bar length of the galaxies. According to this parameter, bars can be
classified as fast ( \cal{R}\%\cal{R}$ and the galaxy morphological
type. Our results indicate that independent of the Hubble type, bars have been
formed and then evolve as fast rotators. This observational result will
constrain the scenarios of formation and evolution of bars proposed by
numerical simulations.Comment: 17 pages, 10 figures, accepted for publication in A&
Representations of Quantum Bicrossproduct Algebras
We present a method to construct induced representations of quantum algebras
having the structure of bicrossproduct. We apply this procedure to some quantum
kinematical algebras in (1+1)--dimensions with this kind of structure:
null-plane quantum Poincare algebra, non-standard quantum Galilei algebra and
quantum kappa Galilei algebra.Comment: LaTeX 2e, 35 page
Insights on the stellar mass-metallicity relation from the CALIFA survey
We use spatially and temporally resolved maps of stellar population
properties of 300 galaxies from the CALIFA integral field survey to investigate
how the stellar metallicity (Z*) relates to the total stellar mass (M*) and the
local mass surface density (*) in both spheroidal and disk dominated
galaxies. The galaxies are shown to follow a clear stellar mass-metallicity
relation (MZR) over the whole 10 to 10 M range. This
relation is steeper than the one derived from nebular abundances, which is
similar to the flatter stellar MZR derived when we consider only young stars.
We also find a strong relation between the local values of * and Z* (the
ZR), betraying the influence of local factors in determining Z*. This
shows that both local (*-driven) and global (M*-driven) processes are
important in determining the metallicity in galaxies. We find that the overall
balance between local and global effects varies with the location within a
galaxy. In disks, * regulates Z*, producing a strong ZR whose
amplitude is modulated by M*. In spheroids it is M* who dominates the physics
of star formation and chemical enrichment, with * playing a minor,
secondary role. These findings agree with our previous analysis of the star
formation histories of CALIFA galaxies, which showed that mean stellar ages are
mainly governed by surface density in galaxy disks and by total mass in
spheroids.Comment: 6 pages, 3 figures, accepted for publication in ApJ
CALIFA, the Calar Alto Legacy Integral Field Area survey: IV. Third public data release
This paper describes the third public data release (DR3) of the Calar Alto Legacy Integral Field Area (CALIFA) survey. Science-grade quality data for 667 galaxies are made public, including the 200 galaxies of the second public data release (DR2). Data were obtained with the integral-field spectrograph PMAS/PPak mounted on the 3.5 m telescope at the Calar Alto Observatory. Three different spectral setups are available: i) a low-resolution V500 setup covering the wavelength range 3745-7500 Å (4240-7140 Å unvignetted) with a spectral resolution of 6.0 Å (FWHM) for 646 galaxies, ii) a medium-resolution V1200 setup covering the wavelength range 3650-4840 Å (3650-4620 Å unvignetted) with a spectral resolution of 2.3 Å (FWHM) for 484 galaxies, and iii) the combination of the cubes from both setups (called COMBO) with a spectral resolution of 6.0 Å and a wavelength range between 3700-7500 Å (3700-7140 Å unvignetted) for 446 galaxies. The Main Sample, selected and observed according to the CALIFA survey strategy covers a redshift range between 0.005 and 0.03, spans the color-magnitude diagram and probes a wide range of stellar masses, ionization conditions, and morphological types. The Extension Sample covers several types of galaxies that are rare in the overall galaxy population and are therefore not numerous or absent in the CALIFA Main Sample. All the cubes in the data release were processed using the latest pipeline, which includes improved versions of the calibration frames and an even further improved image reconstruction quality. In total, the third data release contains 1576 datacubes, including ~1.5 million independent spectra. © 2016 ESO.SFS thanks the CONACYT-125180 and DGAPA-IA100815 projects for providing him support in this study. R.G.B., R.G.D., and E.P. are supported by grants AYA2014-57490-P and JA-FQM-2828. SZ is supported by the EU Marie Curie Integration Grant >SteMaGE> No. PCIG12-GA-2012-326466 (Call Identifier: FP7-PEOPLE-2012 CIG). J. F.-B. from grant AYA2013-48226-C3-1-P from the Spanish Ministry of Economy and Competitiveness (MINECO), as well as from the FP7 Marie Curie Actions of the European Commission, via the Initial Training Network DAGAL under REA grant agreement 289313 B.G-L- acknowledges financial support by the Spanish MINECO under grants AYA2013-41656-P and AYA2015-68217-P Support for L.G. is provided by the Ministry of Economy, Development, and Tourism's Millennium Science Initiative through grant IC12009, awarded to The Millennium Institute of Astrophysics, MAS. L.G. also acknowledges support by CONICYT through FONDECYT grant 3140566, and AYA2013-42227-P from the Spanish Ministerio de Ciencia e Innovacion and TIC 114 and PO08-TIC-3531 from Junta de Andalucia. AG acknowledges support from the FP7/2007-2013 under grant agreement no. 267251 (AstroFIt). RAM was funded by the Spanish programme of International Campus of Excellence Moncloa (CEI). JMA acknowledges support from the European Research Council Starting Grant (SEDmorph; P.I. V. Wild). I.M. and A.d.O. acknowledge the support by the projects AYA2010-15196 from the Spanish Ministerio de Ciencia e Innovacion and TIC 114 and PO08-TIC-3531 from Junta de Andalucia. AMI acknowledges support from Agence Nationale de la Recherche through the STILISM project (ANR-12-BS05-0016-02). M.M. acknowledges financial support from AYA2010-21887-004-02 from the Ministerio de Economia y Competitividad. PSB acknowledges support from the Ramon y Cajal program, grant ATA2010-21322-C03-02 from the Spanish Ministry of Economy and Competitiveness (MINECO). C.J.W. acknowledges support through the Marie Curie Career Integration Grant 303912. V.W. acknowledges support from the European Research Council Starting Grant (SEDMorph P.I. V. Wild) and European Career Re-integration Grant (Phiz-Ev P.I. V. Wild). YA acknowledges financial support from the Ramon y Cajal programme (RyC-2011-09461) and project AYA2013-47742-C4-3-P, both managed by the Ministerio de Economia y Competitividad, as well as the >Study of Emission-Line Galaxies with Integral Field Spectroscopy> (SELGIFS) programme, funded by the EU (FP7-PEOPLE-2013-IRSES-612701) within the Marie-Sklodowska-Curie Actions scheme. ROM acknowledges support from CAPES (Brazil) through a PDJ fellowship from project 88881.030413/2013-01, program CSF-PVE.Peer Reviewe
The O3N2 and N2 abundance indicators revisited: improved calibrations based on CALIFA and Te-based literature data
The use of IFS is since recently allowing to measure the emission line fluxes
of an increasingly large number of star-forming galaxies both locally and at
high redshift. The main goal of this study is to review the most widely used
empirical oxygen calibrations, O3N2 and N2, by using new direct abundance
measurements. We pay special attention to the expected uncertainty of these
calibrations as a function of the index value or abundance derived and the
presence of possible systematic offsets. This is possible thanks to the
analysis of the most ambitious compilation of Te-based HII regions to date.
This new dataset compiles the Te-based abundances of 603 HII regions extracted
from the literature but also includes new measurements from the CALIFA survey.
Besides providing new and improved empirical calibrations for the gas
abundance, we also present here a comparison between our revisited calibrations
with a total of 3423 additional CALIFA HII complexes with abundances derived
using the ONS calibration by Pilyugin et al. (2010). The combined analysis of
Te-based and ONS abundances allows us to derive their most accurate calibration
to date for both the O3N2 and N2 single-ratio indicators, in terms of all
statistical significance, quality and coverage of the space of parameters. In
particular, we infer that these indicators show shallower abundance
dependencies and statistically-significant offsets compared to those of Pettini
and Pagel (2004), Nagao et al. (2006) and P\'erez-Montero and Contini (2009).
The O3N2 and N2 indicators can be empirically applied to derive oxygen
abundances calibrations from either direct abundance determinations with random
errors of 0.18 and 0.16, respectively, or from indirect ones (but based on a
large amount of data) reaching an average precision of 0.08 and 0.09 dex
(random) and 0.02 and 0.08 dex (systematic; compared to the direct
estimations),respectively.Comment: 12 pages, 5 figures, accepted for publication in A&
Graded contractions and bicrossproduct structure of deformed inhomogeneous algebras
A family of deformed Hopf algebras corresponding to the classical maximal
isometry algebras of zero-curvature N-dimensional spaces (the inhomogeneous
algebras iso(p,q), p+q=N, as well as some of their contractions) are shown to
have a bicrossproduct structure. This is done for both the algebra and, in a
low-dimensional example, for the (dual) group aspects of the deformation.Comment: LaTeX file, 20 pages. Trivial changes. To appear in J. Phys.
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