684 research outputs found
Communes d’Aulus-les-Bains et Suc-et-Sentenac
No full textLa prospection inventaire réalisée en 2015 s’est concentrée sur la commune de Suc-et-Sentenac et plus précisément la zone ouest de la forêt domaniale située juste à l’est du Port de Lers. En effet, ce secteur s’est avéré particulièrement riche en vestiges anthropiques. L’enquête de terrain a ciblé la couronne forestière de la tourbière de Bernadouze qui est au cœur d’une recherche en écologie globale pilotée par l’OHM Haut-Vicdessos dirigée par D. Galop (laboratoire GEODE). Cette campagne de ..
Nomenclature for HKT transporters, key determinants of plant salinity tolerance
No full textJ. Damien Platten, Olivier Cotsaftis, Pierre Berthomieu, Hans Bohnert, Romola J. Davenport, David J. Fairbairn, Tomoaki Horie, Roger A. Leigh, Hong-Xuan Lin, Sheng Luan, Pascal Mäser, Omar Pantoja, Alonso Rodríguez-Navarro, Daniel P. Schachtman, Julian I. Schroeder, Hervé Sentenac, Nobuyuki Uozumi, Anne-Aliénor Véry, Jian-Kang Zhu, Elizabeth S. Dennis and Mark Teste
Modulation of yeast genome expression in response to defective RNA polymerase III-dependent transcription
No full textIdentification of an ortholog of the eukaryotic RNA polymerase III subunit RPC34 in Crenarchaeota and Thaumarchaeota suggests specialization of RNA polymerases for coding and non-coding RNAs in Archaea.
No full textContains fulltext :
80405.pdf (Publisher’s version ) (Open Access)One of the hallmarks of eukaryotic information processing is the co-existence of 3 distinct, multi-subunit RNA polymerase complexes that are dedicated to the transcription of specific classes of coding or non-coding RNAs. Archaea encode only one RNA polymerase that resembles the eukaryotic RNA polymerase II with respect to the subunit composition. Here we identify archaeal orthologs of the eukaryotic RNA polymerase III subunit RPC34. Genome context analysis supports a function of this archaeal protein in the transcription of non-coding RNAs. These findings suggest that functional separation of RNA polymerases for protein-coding genes and non-coding RNAs might predate the origin of the Eukaryotes
The parabolic implosion for f0(z) = z + z v+1 + φ(2v=Z)
No full textIn this thesis
we examine the bifurcation in behaviour (for
the dynamics)
which occurs
when we perturb the holomorphic
germ
fo(z)
=z+ zv+1 +
O(zv+2) defined in
a neigh-
bourhood
of
0,
so that the
multiple
fixed
point at
0
splits
into
v+1
fixed
points
(counted
with multiplicity).
The
phenomenon observed is
called
the
parabolic
implosion,
since
the
perturbation will
typically
cause the filled Julia
set
(if it is defined) to "implode. "
The
main tool
used
for
studying
this bifurcation is the Fatou
coordinates and
the
associated
Ecalle
cylinders.
We
show the existence of
these for
a
family
of well
behaved
f's
close to fo,
and
that these depend continuously upon
f.
Each
well
behaved f
will
have
a gate structure which gives a qualitative
description
of the "egg-beater dynamic" for f. Each
gate
between the fixed
points of
f
will
have
an associated complex number called
the lifted
phase.
(Minus
the
real part of
the lifted
phase is
a rough measure of
how
many
iterations it takes
for
an orbit to
pass through the
gate. ) The
existence of maps with any
desired
gate structure and any
(sensible) lifted
phases is
shown.
This leads to
a simple parameterisation of
the
well
behaved maps.
We
are particularly
interested in
sequences fk
→
fo
where all
the lifted
phases of the
fk
converge to
some
limits,
modulo
Z. We
show that there is
a non-trivial
Lavaurs
reap
g associated with these limits,
which commutes with
fo. The dynamics
of
fk
are shown
to (in
some sense) converge to the dynamics
of
the
system
(fo,
g).
We
also prove
that for
any
Lavaurs map g there is
a sequence fk
→
fo
so that
fk
k
→ g
as
k
→ +oo, uniformly on compact sets
Mapping desiccation fissures using 3-D electrical resistivity tomography
No full textDiscontinuities which may form in a soil mass due to desiccation have been shown to be a source of engineering concern in situations where low permeability barriers are required. Current methods for assessing the condition of such geo-barriers, are mainly based on visual inspections, which are inadequate when the soil surface is obscured by vegetation. Electrical Resistivity Tomography (ERT) has been shown to be sensitive to the presence of fissures in 2-D with inversion models mapping the fissure's positions and enabling their growth to be monitored. This paper presents a method for mapping fissured networks in 3-D using miniature arrays under laboratory conditions. The results of two experiments using compacted clay from two separate embankments show a good comparison between the visible surface fissures and the surface model obtained from a 3-D inversion, as well as showing good agreement between the vertical sections of the model and the exposed model interior following dissection. Additionally the results confirm that the 3-D method is suitable for monitoring the onset of fissuring. A comparison of Schlumberger, Dipole–Dipole and combined arrays for visualising the fissures is also presented, indicating that the combined method produces the most accurate image of the subsurface, while the Schlumberger array provides a greater resolution than the Dipole–Dipole array, alongside the added benefit of shorter survey times
Structure-function analysis of the RNA polymerase III subcomplex C17/25 and genome-wide distribution of RNA polymerase II
No full text
The RPC31 gene of Saccharomyces cerevisiae encodes a subunit of RNA polymerase C (III) with an acidic tail.
No full textInternational audienceThe RPC31 gene encoding the C31 subunit of Saccharomyces cerevisiae RNA polymerase C (III) has been isolated, starting from a C-terminal fragment cloned on a lambda gt11 library. It is unique on the yeast genome and lies on the left arm of chromosome XIV, very close to a NotI site. Its coding sequence perfectly matches the amino acid sequence of two oligopeptides prepared from purified C31. It is also identical to the ACP2 gene previously described as encoding an HMG1-like protein (W. Haggren and D. Kolodrubetz, Mol. Cell. Biol. 8:1282-1289, 1988). Thus, ACP2 and RPC31 are allelic and encode a subunit of RNA polymerase C. The c31 protein has a highly acidic C-terminal tail also found in several other chromatin-interacting proteins, including animal HMG1. Outside this domain, however, there is no appreciable homology to any known protein. The growth phenotypes of a gene deletion, of insertions, and of nonsense mutations indicate that the C31 protein is strictly required for cell growth and that most of the acidic domain is essential for its function. Random mutagenesis failed to yield temperature-sensitive mutants, but a slowly growing mutant was constructed by partial suppression of a UAA nonsense allele of RPC31. Its reduced rate of tRNA synthesis in vivo relative to 5.8S rRNA supports the hypothesis that the C31 protein is a functional subunit of RNA polymerase C
Desiccation cracking detection using 2-D and 3-D electrical resistivity tomography : validation on a flood embankment
No full textDesiccation cracks forming in earthen structures are a known source of engineering concern. In particular such fissures forming in flood embankments can affect their stability leading to failure when overtopped. These and other problems related to safety have raised the importance of using efficient and reliable tools, especially when relatively fast, non-invasive and extensive investigations are required. Geophysical techniques, such as Electrical Resistivity Tomography (ERT), allow for accurate assessment and monitoring of shallow depths within engineering structures. The presented study examines the use of miniature and field scale ERT on a fissured flood embankment near Hull, UK. Two separate sections were surveyed in summer and winter using both 2-D and 3-D configurations, allowing seasonal evaluation of embankment condition. The field results were validated through forward modelling, with different fissure configurations and the effect of topography. The results show that the resolution of the cracks increased with smaller electrode spacing. It was found that ERT can be used on a larger scale to detect zones of fissuring with fissured networks being displayed. The ability to detect cracks was diminished when surveying in winter with cracks reducing in size due to seasonal swelling of the soil. The resistivity models obtained showed anomalies with far lower resistivity than those obtained in summer. The study showed that miniature surveys could be used to examine small sections in detail allowing imaging for horizontal subsurface fissures. The larger scale surveys provided important spatial information allowing the distribution of fissures on the embankment to be made. The study recommends that geophysical surveying of flood defences should be used as a routine assessment tool to detect desiccation cracks within the embankment, and that these surveys should be completed in the summer, where cracks are most prominent
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