1,432 research outputs found
Evidence for regulated expression of Telomeric Repeat-containing RNAs (TERRA) in parasitic trypanosomatids
The Telomeric Repeat-containing RNAs (TERRA) participate in the homeostasis of telomeres in higher eukaryotes. Here, we investigated the expression of TERRA in Leishmania spp. and Trypanosoma brucei and found evidences for its expression as a specific RNA class. The trypanosomatid TERRA are heterogeneous in size and partially polyadenylated. The levels of TERRA transcripts appear to be modulated through the life cycle in both trypanosomatids investigated, suggesting that TERRA play a stage-specific role in the life cycle of these early-branching eukaryotes
Tollip, an early regulator of the acute inflammatory response in the substantia nigra.
Tollip is a ubiquitously expressed protein, originally described as a modulator of the IL-1R/TLR-NF-κB signaling pathways. Although this property has been well characterized in peripheral cells, and despite some evidence of its expression in the central nervous system, the role of Tollip in neuroinflammation remains poorly understood. The present study sought to explore the implication of Tollip in inflammation in the substantia nigra pars compacta, the structure affected in Parkinson's disease.
We first investigated Tollip distribution in the midbrain by immunohistochemistry. Then, we addressed TLR4-mediated response by intra-nigral injections of lipopolysaccharide (LPS), a TLR4 agonist, on inflammatory markers in Tollip knockout (KO) and wild-type (WT) mice.
We report an unexpectedly high Tollip immunostaining in dopaminergic neurons of the mice brain. Second, intra-nigral injection of LPS led to increased susceptibility to neuroinflammation in Tollip KO compared to Tollip WT mice. This was demonstrated by a significant increase of tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), interleukin 6 (IL-6), and interferon gamma (IFN-γ) messenger RNA (mRNA) in the midbrain of Tollip KO mice upon LPS injection. Consistently, brain rAAV viral vector transduction with a nuclear factor kappa B (NF-κB)-inducible reporter gene confirmed increased NF-κB activation in Tollip KO mice. Lastly, Tollip KO mice displayed higher inducible NO synthase (iNOS) production, both at the messenger and protein level when compared to LPS-injected WT mice. Tollip deletion also aggravated LPS-induced oxidative and nitrosative damages, as indicated by an increase of 8-oxo-2'-deoxyguanosine and nitrotyrosine immunostaining, respectively.
Altogether, these findings highlight a critical role of Tollip in the early phase of TLR4-mediated neuroinflammation. As brain inflammation is known to contribute to Parkinson's disease, Tollip may be a potential target for neuroprotection
Managing Performance Throughout Periods of Travel
Understanding the impact of travel on physical performance is an increasing area of interest for the strength and conditioning practitioner. Previous research surrounding the effect of travel on the physiology of an athlete has focused on sleep. Of concern to coaches and athletes are strategies to help attenuate any detrimental impact of travel on subsequent performance. The aim of this article is to provide informative practical guidelines for before, during, and after travel that can be implemented by coaches and athletes. The key coping strategies addressed include timed light exposure; managing sleep deprivation and nutritional recommendations
ESPRESSO: The next European exoplanet hunter
The acronym ESPRESSO stems for Echelle SPectrograph for Rocky Exoplanets and
Stable Spectroscopic Observations; this instrument will be the next VLT high
resolution spectrograph. The spectrograph will be installed at the
Combined-Coud\'e Laboratory of the VLT and linked to the four 8.2 m Unit
Telescopes (UT) through four optical Coud\'e trains. ESPRESSO will combine
efficiency and extreme spectroscopic precision. ESPRESSO is foreseen to achieve
a gain of two magnitudes with respect to its predecessor HARPS, and to improve
the instrumental radial-velocity precision to reach the 10 cm/s level. It can
be operated either with a single UT or with up to four UTs, enabling an
additional gain in the latter mode. The incoherent combination of four
telescopes and the extreme precision requirements called for many innovative
design solutions while ensuring the technical heritage of the successful HARPS
experience. ESPRESSO will allow to explore new frontiers in most domains of
astrophysics that require precision and sensitivity. The main scientific
drivers are the search and characterization of rocky exoplanets in the
habitable zone of quiet, nearby G to M-dwarfs and the analysis of the
variability of fundamental physical constants. The project passed the final
design review in May 2013 and entered the manufacturing phase. ESPRESSO will be
installed at the Paranal Observatory in 2016 and its operation is planned to
start by the end of the same year.Comment: 12 pages, figures included, accepted for publication in Astron. Nach
HARPS3 for a roboticized Isaac Newton telescope
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.We present a description of a new instrument development, HARPS3, planned to be installed on an upgraded and roboticized Isaac Newton Telescope by end-2018. HARPS3 will be a high resolution (R = 115,000) echelle spectrograph with a wavelength range from 380-690 nm. It is being built as part of the Terra Hunting Experiment - a future 10 year radial velocity measurement programme to discover Earth-like exoplanets. The instrument design is based on the successful HARPS spectrograph on the 3.6m ESO telescope and HARPS-N on the TNG telescope. The main changes to the design in HARPS3 will be: a customised fibre adapter at the Cassegrain focus providing a stabilised beam feed and on-sky fibre diameter ~ 1.4 arcsec, the implementation of a new continuous flow cryostat to keep the CCD temperature very stable, detailed characterisation of the HARPS3 CCD to map the effective pixel positions and thus provide an improved accuracy wavelength solution, an optimised integrated polarimeter and the instrument integrated into a robotic operation. The robotic operation will optimise our programme which requires our target stars to be measured on a nightly basis. We present an overview of the entire project, including a description of our anticipated robotic operation.R.H. acknowledges the Science and Technologies Facilities Council (STFC) for his PhD studentship award (2015).J.I.G.H. acknowledges financial support from the Spanish Ministry of Economy and Competitiveness (MINECO)
under the 2013 Ram´on y Cajal program MINECO RYC-2013-14875.J.I.G.H., R.R., and S.S.T. also acknowledge the Spanish ministry project MINECO AYA2014-56359-P.NP and ES are grateful to Knut and Alice Wallenberg Foundation for a generous support of the Swedish contribution
to the THE project.AD acknowledges the support from Russian Foundation for Basic Research as part of research grant 15-52-12371
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
Combined search for the quarks of a sequential fourth generation
Results are presented from a search for a fourth generation of quarks
produced singly or in pairs in a data set corresponding to an integrated
luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in
2011. A novel strategy has been developed for a combined search for quarks of
the up and down type in decay channels with at least one isolated muon or
electron. Limits on the mass of the fourth-generation quarks and the relevant
Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a
simple extension of the standard model with a sequential fourth generation of
fermions. The existence of mass-degenerate fourth-generation quarks with masses
below 685 GeV is excluded at 95% confidence level for minimal off-diagonal
mixing between the third- and the fourth-generation quarks. With a mass
difference of 25 GeV between the quark masses, the obtained limit on the masses
of the fourth-generation quarks shifts by about +/- 20 GeV. These results
significantly reduce the allowed parameter space for a fourth generation of
fermions.Comment: Replaced with published version. Added journal reference and DO
High-resolution analysis of multi-copy variant surface glycoprotein gene expression sites in African trypanosomes
BACKGROUND: African trypanosomes cause lethal diseases in humans and animals and escape host immune attack by switching the expression of Variant Surface Glycoprotein (VSG) genes. The expressed VSGs are located at the ends of telomeric, polycistronic transcription units known as VSG expression sites (VSG-ESs). Each cell has many VSG-ESs but only one is transcribed in bloodstream-form parasites and all of them are inactive upon transmission to the insect vector mid-gut; a subset of monocistronic metacyclic VSG-ESs are then activated in the insect salivary gland. Deep-sequence analyses have been informative but assigning sequences to individual VSG-ESs has been challenging because they each contain closely related expression-site associated genes, or ESAGs, thought to contribute to virulence. RESULTS: We utilised ART, an in silico short read simulator to demonstrate the feasibility of accurately aligning reads to VSG-ESs. Then, using high-resolution transcriptomes from isogenic bloodstream and insect-stage Lister 427 Trypanosoma brucei, we uncover increased abundance in the insect mid-gut stage of mRNAs from metacyclic VSG-ESs and of mRNAs from the unusual ESAG, ESAG10. Further, we show that the silencing associated with allelic exclusion involves repression focussed at the ends of the VSG-ESs. We also use the approach to report relative fitness costs following ESAG RNAi from a genome-scale screen. CONCLUSIONS: By assigning sequences to individual VSG-ESs we provide new insights into VSG-ES transcription control, allelic exclusion and impacts on fitness. Thus, deeper insights into the expression and function of regulated multi-gene families are more accessible than previously anticipated. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12864-016-3154-8) contains supplementary material, which is available to authorized users
Recommended from our members
Modeling the summertime evolution of sea-ice melt ponds
1] We present a mathematical model describing the summer melting of sea ice. We simulate the evolution of melt ponds and determine area coverage and total surface ablation. The model predictions are tested for sensitivity to the melt rate of unponded ice, enhanced melt rate beneath the melt ponds, vertical seepage, and horizontal permeability. The model is initialized with surface topographies derived from laser altimetry corresponding to first-year sea ice and multiyear sea ice. We predict that there are large differences in the depth of melt ponds and the area of coverage between the two types of ice. We also find that the vertical seepage rate and the melt rate of unponded ice are important in determining the total surface ablation and area covered by melt ponds
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
- …
