28 research outputs found
A large diversity of non-rhizobial endophytes found in legume root nodules in Flanders (Belgium)
We analysed the genetic properties of non-rhizobial root nodule endophytes (NRE) isolated from indigenous legumes in Flanders. In total, 654 isolates were obtained from 30 different plant species within the Faboideae legume subfamily. Partial sequencing of the 16S rRNA gene revealed a large diversity of different taxa from the classes Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Actinobacteria, Firmibacteria, Flavobacteria and Sphingobacteria. Many of the isolates belonged to the genera Bacillus (17.9%) and Pseudomonas (15.9%). No symbiosis (nodC) or nitrogen fixation related genes (nifH) could be detected amongst the isolates, which indicate the endophytic nature of the bacteria. Statistical analysis grouped the investigated plant species into six clusters according to the presence of particular NRE. However, no correlations could be found within these six clusters towards plant tribes or ecoregions the plants had been sampled from. Cluster analysis of the ecoregions according to the presence of NRE, revealed correlations between bacterial genera and those areas. However, groups present in the ecoregions did not correlate with the groups present in the different plant clusters. When combining our previous study on rhizobial diversity recovered from the same sampling campaign (De Meyer etal., 2011) with the current study, 84.1% of the isolates belonged to the traditional rhizobia groups and only 15.9% were NRE. The Loamy ecoregion yielded the lowest number of culturable NRE (8.04%) and the Campine ecoregion the highest number (24.19%). The present study highlights the frequent presence of these NRE in root nodules. The occurrence of certain rhizobia was correlated with the presence of particular NRE, suggesting their presence may not be accidental, however their functions remain unclear at this point
Caplacizumab reduces the frequency of major thromboembolic events, exacerbations, and death in patients with acquired thrombotic thrombocytopenic purpura.
BACKGROUND
Acquired thrombotic thrombocytopenic purpura (aTTP) is a life-threatening autoimmune thrombotic microangiopathy. In spite of treatment with plasma exchange and immunosuppression, patients remain at risk for thrombotic complications, exacerbations and death. In the Phase II TITAN study, treatment with caplacizumab, an anti-vWF Nanobody(Âź) , was shown to reduce the time to confirmed platelet count normalization and exacerbations during treatment.
OBJECTIVE
The clinical benefit of caplacizumab was further investigated in a post-hoc analysis of the incidence of major thromboembolic events and exacerbations during the study drug treatment period and TTP-related death during the study.
METHODS
The Standardized MedDRA Query (SMQ) for 'embolic and thrombotic events' was run to investigate the occurrence of major thromboembolic events and exacerbations in the safety population of the TITAN study, which consisted of 72 patients of whom 35 received caplacizumab and 37 received placebo.
RESULTS
Four events (1 pulmonary embolism and 3 aTTP exacerbations) were reported in 4 patients in the caplacizumab group, while 20 such events were reported in 14 patients in the placebo group (2 acute myocardial infarctions, 1 ischemic and 1 hemorrhagic stroke, 1 pulmonary embolism, 1 deep vein thrombosis, 1 venous thrombosis and 13 aTTP exacerbations). Two of the placebo-treated patients died from aTTP during the study.
CONCLUSION
In total, 11.4% of caplacizumab-treated patients versus 43.2% of placebo-treated patients experienced one or more major thromboembolic event, an exacerbation or died. This analysis shows the potential for caplacizumab to reduce the risk of major thromboembolic morbidities and mortality associated with aTTP. This article is protected by copyright. All rights reserved
The dynamics of quark-gluon plasma and AdS/CFT
In these pedagogical lectures, we present the techniques of the AdS/CFT
correspondence which can be applied to the study of real time dynamics of a
strongly coupled plasma system. These methods are based on solving
gravitational Einstein's equations on the string/gravity side of the AdS/CFT
correspondence. We illustrate these techniques with applications to the
boost-invariant expansion of a plasma system. We emphasize the common
underlying AdS/CFT description both in the large proper time regime where
hydrodynamic dynamics dominates, and in the small proper time regime where the
dynamics is far from equilibrium. These AdS/CFT methods provide a fascinating
arena interrelating General Relativity phenomenae with strongly coupled gauge
theory physics.Comment: 35 pages, 3 figures. Lectures at the 5th Aegean summer school, `From
gravity to thermal gauge theories: the AdS/CFT correspondence'. To appear in
the proceedings in `Lecture Notes in Physics
Long-Range Rapidity Correlations in Heavy Ion Collisions at Strong Coupling from AdS/CFT
We use AdS/CFT correspondence to study two-particle correlations in heavy ion
collisions at strong coupling. Modeling the colliding heavy ions by shock waves
on the gravity side, we observe that at early times after the collision there
are long-range rapidity correlations present in the two-point functions for the
glueball and the energy-momentum tensor operators. We estimate rapidity
correlations at later times by assuming that the evolution of the system is
governed by ideal Bjorken hydrodynamics, and find that glueball correlations in
this state are suppressed at large rapidity intervals, suggesting that
late-time medium dynamics can not "wash out" the long-range rapidity
correlations that were formed at early times. These results may provide an
insight on the nature of the "ridge" correlations observed in heavy ion
collision experiments at RHIC and LHC, and in proton-proton collisions at LHC.Comment: 32 pages, 2 figures; v2: typos corrected, references adde
Quantum Fluctuations and the Unruh Effect in Strongly-Coupled Conformal Field Theories
Through the AdS/CFT correspondence, we study a uniformly accelerated quark in
the vacuum of strongly-coupled conformal field theories in various dimensions,
and determine the resulting stochastic fluctuations of the quark trajectory.
From the perspective of an inertial observer, these are quantum fluctuations
induced by the gluonic radiation emitted by the accelerated quark. From the
point of view of the quark itself, they originate from the thermal medium
predicted by the Unruh effect. We scrutinize the relation between these two
descriptions in the gravity side of the correspondence, and show in particular
that upon transforming the conformal field theory from Rindler space to the
open Einstein universe, the acceleration horizon disappears from the boundary
theory but is preserved in the bulk. This transformation allows us to directly
connect our calculation of radiation-induced fluctuations in vacuum with the
analysis by de Boer et al. of the Brownian motion of a quark that is on average
static within a thermal medium. Combining this same bulk transformation with
previous results of Emparan, we are also able to compute the stress-energy
tensor of the Unruh thermal medium.Comment: 1+31 pages; v2: reference adde
Early-Time Energy Loss in a Strongly-Coupled SYM Plasma
We carry out an analytic study of the early-time motion of a quark in a
strongly-coupled maximally-supersymmetric Yang-Mills plasma, using the AdS/CFT
correspondence. Our approach extracts the first thermal effects as a small
perturbation of the known quark dynamics in vacuum, using a double expansion
that is valid for early times and for (moderately) ultrarelativistic quark
velocities. The quark is found to lose energy at a rate that differs
significantly from the previously derived stationary/late-time result: it
scales like T^4 instead of T^2, and is associated with a friction coefficient
that is not independent of the quark momentum. Under conditions representative
of the quark-gluon plasma as obtained at RHIC, the early energy loss rate is a
few times smaller than its late-time counterpart. Our analysis additionally
leads to thermally-corrected expressions for the intrinsic energy and momentum
of the quark, in which the previously discovered limiting velocity of the quark
is found to appear naturally.Comment: 39 pages, no figures. v2: Minor corrections and clarifications.
References added. Version to be published in JHE
Improved Holographic QCD
We provide a review to holographic models based on Einstein-dilaton gravity
with a potential in 5 dimensions. Such theories, for a judicious choice of
potential are very close to the physics of large-N YM theory both at zero and
finite temperature. The zero temperature glueball spectra as well as their
finite temperature thermodynamic functions compare well with lattice data. The
model can be used to calculate transport coefficients, like bulk viscosity, the
drag force and jet quenching parameters, relevant for the physics of the
Quark-Gluon Plasma.Comment: LatEX, 65 pages, 28 figures, 9 Tables. Based on lectures given at
several Schools. To appear in the proceedinds of the 5th Aegean School
(Milos, Greece
Pre-clinical imaging of transgenic mouse models of neuroblastoma using a dedicated 3-element solenoid coil on a clinical 3T platform.
Background The use of clinical MRI scanners to conduct pre-clinical research facilitates comparisons with clinical studies. Here the utility and sensitivity of anatomical and functional MRI data/biomarkers acquired from transgenic mouse models of neuroblastoma using a dedicated radiofrequency (RF) coil on a clinical 3T scanner was evaluated.Methods Multiparametric MRI of transgenic mice bearing abdominal neuroblastomas was performed at 3T, and data cross-referenced to that acquired from the same mice on a pre-clinical 7T MRI system. T2-weighted imaging, quantitation of the native longitudinal relaxation time (T1) and the transverse relaxation rate (R2*), and dynamic contrast-enhanced (DCE)-MRI, was used to assess tumour volume, phenotype and response to cyclophosphamide or cabozantinib.Results Excellent T2-weighted image contrast enabled clear tumour delineation at 3T. Significant correlations of tumour volume (R=0.98, P2* (R=0.87, P2* (Ptrans for each tumour (median Ktrans values of 0.202, 0.168 and 0.114âmin-1). Cyclophosphamide elicited a significant reduction in both tumour burden (P1 (P<0.01), whereas cabozantinib induced significant (P<0.01) tumour growth delay.Conclusions Simultaneous multiparametric MRI of multiple tumour-bearing animals using this coil arrangement at 3T can provide high efficiency/throughput for both phenotypic characterisation and evaluation of novel therapeutics, and facilitate the introduction of functional MRI biomarkers into aligned imaging-embedded clinical trials