899 research outputs found
Functional Microbial Features Driving Community Assembly During Seed Germination and Emergence
Microbial interactions occurring on and around seeds are especially important for plant fitness since seed-borne microorganisms are the initial source of inoculum for the plant microbiota. In this study, we analyze structural and functional changes occurring within the plant microbiota at these early stages of the plant cycle, namely germination and emergence. To this purpose, we performed shotgun DNA sequencing of microbial assemblages associated to seeds, germinating seeds and seedlings of two plant species: bean and radish. We observed an enrichment of and during emergence and a set of functional traits linked to copiotrophy that could be responsible for this selection as a result of an increase of nutrient availability after germination. Representative bacterial isolates of taxa that are selected in seedlings showed indeed faster bacterial growth rate in comparison to seed-associated bacteria isolates. Finally, binning of metagenomics contigs results in the reconstruction of population genomes of the major bacterial taxa associated to the samples. Together, our results demonstrate that, although seed microbiota varied across plant species, nutrient availability during germination elicits changes of the composition of microbial communities by potentially selecting microbial groups with functional traits linked to copiotrophy. The data presented here represents the first attempts to empirically assess changes in the microbial community during plant emergence and moves us toward a more holistic understanding of the plant microbiome
CacheZoom: How SGX Amplifies The Power of Cache Attacks
In modern computing environments, hardware resources are commonly shared, and
parallel computation is widely used. Parallel tasks can cause privacy and
security problems if proper isolation is not enforced. Intel proposed SGX to
create a trusted execution environment within the processor. SGX relies on the
hardware, and claims runtime protection even if the OS and other software
components are malicious. However, SGX disregards side-channel attacks. We
introduce a powerful cache side-channel attack that provides system adversaries
a high resolution channel. Our attack tool named CacheZoom is able to virtually
track all memory accesses of SGX enclaves with high spatial and temporal
precision. As proof of concept, we demonstrate AES key recovery attacks on
commonly used implementations including those that were believed to be
resistant in previous scenarios. Our results show that SGX cannot protect
critical data sensitive computations, and efficient AES key recovery is
possible in a practical environment. In contrast to previous works which
require hundreds of measurements, this is the first cache side-channel attack
on a real system that can recover AES keys with a minimal number of
measurements. We can successfully recover AES keys from T-Table based
implementations with as few as ten measurements.Comment: Accepted at Conference on Cryptographic Hardware and Embedded Systems
(CHES '17
The fundamental parameters of the roAp star Equulei
Physical processes working in the stellar interiors as well as the evolution
of stars depend on some fundamental stellar properties, such as mass, radius,
luminosity, and chemical abundances. A classical way to test stellar interior
models is to compare the predicted and observed location of a star on
theoretical evolutionary tracks in a H-R diagram. This requires the best
possible determinations of stellar mass, radius, luminosity and abundances. To
derive its fundamental parameters, we observed the well-known rapidly
oscillating Ap star, Equ, using the visible spectro-interferometer
VEGA installed on the optical CHARA array. We computed the calibrated squared
visibility and derived the limb-darkened diameter. We used the whole energy
flux distribution, the parallax and this angular diameter to determine the
luminosity and the effective temperature of the star. We obtained a
limb-darkened angular diameter of 0.564~~0.017~mas and deduced a radius of
~=~2.20~~0.12~. Without considering the multiple
nature of the system, we derived a bolometric flux of erg~cm~s and an effective temperature of
7364~~235~K, which is below the effective temperature that has been
previously determined. Under the same conditions we found a luminosity of
~=~12.8~~1.4~. When the contribution of the closest
companion to the bolometric flux is considered, we found that the effective
temperature and luminosity of the primary star can be, respectively, up to
~100~K and up to ~0.8~L smaller than the values mentioned
above.These new values of the radius and effective temperature should bring
further constraints on the asteroseismic modelling of the star.Comment: Accepted by A&
Relationship between carcass weight, adipose tissue androstenone level and expression of the hepatic 3β-hydroxysteroid dehydrogenase in entire commercial pigs
Boar taint is a major meat-quality defect in pigs and is due to excessive accumulation of skatole and androstenone in adipose tissue. The present work investigated the relationship between carcass weight, levels of skatole and androstenone in adipose tissue, and expression of the hepatic androstenone-metabolising enzyme 3β-hydroxysteroid dehydrogenase (3β-HSD), in 22 entire male and 22 entire female crossbred pigs (Large White (40%) × Landrace (40%) × Duroc (20%)). Animals of each gender were divided into two subgroups (11 pigs in each subgroup): (i) conventional weight (carcass weight 59 to 77 kg) and (ii) heavy weight (carcass weight 84 to 95 kg). No relationship between carcass weight and adipose tissue skatole level was found for entire male pigs (r 2 = 0.013, P > 0.05). There was a significant negative relationship between carcass weight and expression of the hepatic 3β-HSD protein (r 2 = 0.502, P 0.05). 3β-HSD expression was 59% higher in conventional-weight male pigs when compared with heavy-weight animals (P < 0.05) and 36% higher in heavy-weight females when compared with heavy-weight males (P < 0.05). It is concluded that an increase in slaughter weight of entire commercial crossbred Large White pigs is accompanied by inhibition of expression of the hepatic 3β-HSD protein, which might result in a reduced rate of hepatic androstenone clearance with its subsequent accumulation in adipose tissue. It is suggested that regulation of pig hepatic 3β-HSD expression is under the control of sex hormones. © 2007 The Animal Consortium
Results on the Wess-Zumino consistency condition for arbitrary Lie algebras
The so-called covariant Poincare lemma on the induced cohomology of the
spacetime exterior derivative in the cohomology of the gauge part of the BRST
differential is extended to cover the case of arbitrary, non reductive Lie
algebras. As a consequence, the general solution of the Wess-Zumino consistency
condition with a non trivial descent can, for arbitrary (super) Lie algebras,
be computed in the small algebra of the 1 form potentials, the ghosts and their
exterior derivatives. For particular Lie algebras that are the semidirect sum
of a semisimple Lie subalgebra with an ideal, a theorem by Hochschild and Serre
is used to characterize more precisely the cohomology of the gauge part of the
BRST differential in the small algebra. In the case of an abelian ideal, this
leads to a complete solution of the Wess-Zumino consistency condition in this
space. As an application, the consistent deformations of 2+1 dimensional
Chern-Simons theory based on iso(2,1) are rediscussed.Comment: 39 pages Latex file, 1 eps figure, typos and proof of lemma 5
correcte
Rationale and protocol for using a smartphone application to study autism spectrum disorders: SMARTAUTISM
INTRODUCTION: Longitudinal studies on the evolution of autism spectrum disorder (ASD) symptoms are limited and have primarily used repeated measurements performed several months apart. However, measurements of changes in everyday life should more closely reflect the \u27real life\u27 of the patient and his or her family. We propose to study the child\u27s ASD symptoms and their effect on the quality of life, psychological status and anxiety of the child\u27s parents over a 6-month period using SMARTAUTISM, a smartphone application.
METHOD AND ANALYSIS: This is a prospective, longitudinal, exploratory, open study with a 6-month follow-up period. Data will be recorded longitudinally over multiple weeks under natural conditions. The factors affecting the quality of life and anxiety of parents of children with ASD and the children\u27s functional symptoms will be examined, and the feasibility of using a smartphone application designed for parents of ASD patients will be assessed.
PRIMARY OBJECTIVE: Explore the evolution of a child\u27s behaviour over 6 months and the (psychological and social) effects of these changes on the family.
SECONDARY OBJECTIVE: Assess the feasibility of our application by examining the filling rate and application usage by parents for 6 months. 100 families containing 1 child diagnosed with ASD will be included. At baseline, sociodemographic, psychiatric and medical data will be recorded. The correlations of the general epidemiological variables (primary outcome measure) will be evaluated via multivariate analysis. The application filling rate (relative to the ideal filling rate) will be used to assess the feasibility of the application (secondary outcome measure).
ETHICS AND DISSEMINATION: The SMARTAUTISM study has the approval of the local ethics committee, and data security will be ensured via the use of encryption and a secure medical server. The use of this application will be proposed at autism resource centres across France
An investigation of the close environment of beta Cep with the VEGA/CHARA interferometer
High-precision interferometric measurements of pulsating stars help to
characterize their close environment. In 1974, a close companion was discovered
around the pulsating star beta Cep using the speckle interferometry technique
and features at the limit of resolution (20 milli-arcsecond or mas) of the
instrument were mentioned that may be due to circumstellar material. Beta Cep
has a magnetic field that might be responsible for a spherical shell or
ring-like structure around the star as described by the MHD models. Using the
visible recombiner VEGA installed on the CHARA long-baseline interferometer at
Mt. Wilson, we aim to determine the angular diameter of beta Cep and resolve
its close environment with a spatial resolution up to 1 mas level. Medium
spectral resolution (R=6000) observations of beta Cep were secured with the
VEGA instrument over the years 2008 and 2009. These observations were performed
with the S1S2 (30m) and W1W2 (100m) baselines of the array. We investigated
several models to reproduce our observations. A large-scale structure of a few
mas is clearly detected around the star with a typical flux relative
contribution of 0.23 +- 0.02. Our best model is a co-rotational geometrical
thin ring around the star as predicted by magnetically-confined wind shock
models. The ring inner diameter is 8.2 +- 0.8 mas and the width is 0.6 +- 0.7
mas. The orientation of the rotation axis on the plane of the sky is PA = 60 +-
1 deg, while the best fit of the mean angular diameter of beta Cep gives UD[V]
= 0.22 +- 0.05 mas. Our data are compatible with the predicted position of the
close companion of beta Cep. These results bring additional constraints on the
fundamental parameters and on the future MHD and asteroseismological models of
the star.Comment: Paper accepted for publication in A&A (in press
A mobile data acquisition system
A mobile data aquisition (MobiDAQ) was developed for the ATLAS central hadronic
calorimeter (TileCal). MobiDAQ has been designed in order to test the functionalities of the TileCal
front-end electronics and to acquire calibration data before the final back-end electronics were built
and tested. MobiDAQ was also used to record the first cosmic ray events acquired by an ATLAS
subdetector in the underground experimental area
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