4,426 research outputs found
Long-range correlation and multifractality in Bach's Inventions pitches
We show that it can be considered some of Bach pitches series as a stochastic
process with scaling behavior. Using multifractal deterend fluctuation analysis
(MF-DFA) method, frequency series of Bach pitches have been analyzed. In this
view we find same second moment exponents (after double profiling) in ranges
(1.7-1.8) in his works. Comparing MF-DFA results of original series to those
for shuffled and surrogate series we can distinguish multifractality due to
long-range correlations and a broad probability density function. Finally we
determine the scaling exponents and singularity spectrum. We conclude fat tail
has more effect in its multifractality nature than long-range correlations.Comment: 18 page, 6 figures, to appear in JSTA
On-cloud decision-support system for non-small cell lung cancer histology characterization from thorax computed tomography scans
Non-Small Cell Lung Cancer (NSCLC) accounts for about 85% of all lung cancers. Developing non-invasive techniques for NSCLC histology characterization may not only help clinicians to make targeted therapeutic treatments but also prevent subjects from undergoing lung biopsy, which is challenging and could lead to clinical implications. The motivation behind the study presented here is to develop an advanced on-cloud decision-support system, named LUCY, for non-small cell LUng Cancer histologY characterization directly from thorax Computed Tomography (CT) scans. This aim was pursued by selecting thorax CT scans of 182 LUng ADenocarcinoma (LUAD) and 186 LUng Squamous Cell carcinoma (LUSC) subjects from four openly accessible data collections (NSCLC-Radiomics, NSCLC-Radiogenomics, NSCLC-Radiomics-Genomics and TCGA-LUAD), in addition to the implementation and comparison of two end-to-end neural networks (the core layer of whom is a convolutional long short-term memory layer), the performance evaluation on test dataset (NSCLC-Radiomics-Genomics) from a subject-level perspective in relation to NSCLC histological subtype location and grade, and the dynamic visual interpretation of the achieved results by producing and analyzing one heatmap video for each scan. LUCY reached test Area Under the receiver operating characteristic Curve (AUC) values above 77% in all NSCLC histological subtype location and grade groups, and a best AUC value of 97% on the entire dataset reserved for testing, proving high generalizability to heterogeneous data and robustness. Thus, LUCY is a clinically-useful decision-support system able to timely, non-invasively and reliably provide visually-understandable predictions on LUAD and LUSC subjects in relation to clinically-relevant information
A new scenario for the Domerian-Toarcian transition
Pour tenter de mieux comprendre l’événement d’anoxie océanique globale au Toarcien inférieur, il convient
de remonter aux changements environnementaux qui ont précédé cette phase paroxysmale. En effet, la comparaison des
séquences sédimentaires et biostratigraphiques du passage Domérien-Toarcien entre la Téthys occidentale (Maroc,
Espagne, Portugal) et l’Europe du Nord-Ouest (Causses, Allemagne, Angleterre) fait apparaître une importante lacune
dans la région septentrionale.
La faune d’Arieticeratinae (Emaciaticeras, Canavaria, Fontanelliceras) et d’Harpoceratinae (Lioceratoides, Neolioceratoides),
accompagnée ensuite de Dactylioceras particuliers (groupe mirabile-polymorphum = sous-genre Eodactylites),
fait presque totalement défaut en Europe du Nord-Ouest, alors qu’elle abonde dans les dernières alternances
marno-calcaires, sans changement lithologique notable avec le Domérien des coupes téthysiennes. Cette faune est intercalée
entre les derniers Pleuroceras et les Dactylioceras du groupe tenuicostatum. Ces derniers apparaissent dans les argiles
succédant immédiatement au dernier banc calcaire à Dactylioceras mirabile au Portugal notamment. C’est là le
diachronisme déjà reconnu entre les limites lithostratigraphique (disparition des bancs calcaires) et biostratigraphique
(apparition du genre Dactylioceras) au passage Domérien-Toarcien.
Cette observation peut s’intégrer dans un nouveau scénario paléo-océanographique prenant en compte à la fois la
tendance régressive majeure du Domérien supérieur (conduisant à une lacune régionale importante), l’abondance de matière
charbonneuse dans les premiers dépôts transgressifs du Toarcien et l’événement anoxique global subséquent.
Dans la partie supérieure du Domérien, l’existence d’un fort volcanisme peut être déduite des données relatives
aux variations des isotopes du strontium [McArthur et al., 2000]. A ce pic de strontium sont associées une faible anomalie
négative du δ13
C à la limite Domérien-Toarcien et des valeurs particulièrement élevées du δ18
O [Morettini et Bartolini,
1999]. Nous pensons que cette activité volcanique débute par des émissions massives de SO2 induisant des pluies
acides, un obscurcissement et un refroidissement. A cette phase de refroidissement correspond une augmentation de
l’englacement des pôles et une régression responsable de la lacune majeure évoquée plus haut, particulièrement sensible
dans les mers épicontinentales. Bien que les preuves directes d’une glaciation fini-domérienne fassent actuellement défaut
[Hallam, 2001], le glacio-eustatisme nous semble le seul mécanisme permettant d’expliquer une oscillation marine
importante mais de courte durée [Brandt, 1986 ; Dewey et Pitman, 1998]. En effet, le cycle régression-transgression
s’étale sur environ deux zones d’ammonites, la lacune sédimentaire en elle-même recouvrant essentiellement les
sous-zones à Elisa et Mirabile.
Ce premier épisode serait suivi, dans la zone à Tenuicostatum, par une importante perturbation du cycle du carbone
responsable d’un effet de serre. Le réchauffement, provoquerait alors la transgression bien connue du Toarcien inférieur,
cachetant le hiatus sédimentaire dans la province nord-ouest européenne. L’intervalle de temps correspondant à
cette lacune aurait permis à la végétation de coloniser les immenses surfaces nouvellement émergées. C’est le lessivage
et l’oxydation de la matière organo-humique et bactérienne accumulée pendant cette période, associée à une élévation
de la température, qui aurait enclenché le mécanisme d’anoxie lors du paroxysme de la transgression
The DNA-binding domain of the Chd1 chromatin-remodelling enzyme contains SANT and SLIDE domains
The ATP-dependent chromatin-remodelling enzyme Chd1 is a 168-kDa protein consisting of a double chromodomain, Snf2-related ATPase domain, and a C-terminal DNA-binding domain. Here, we show the DNA-binding domain is required for Saccharomyces cerevisiae Chd1 to bind and remodel nucleosomes. The crystal structure of this domain reveals the presence of structural homology to SANT and SLIDE domains previously identified in ISWI remodelling enzymes. The presence of these domains in ISWI and Chd1 chromatin-remodelling enzymes may provide a means of efficiently harnessing the action of the Snf2-related ATPase domain for the purpose of nucleosome spacing and provide an explanation for partial redundancy between these proteins. Site directed mutagenesis was used to identify residues important for DNA binding and generate a model describing the interaction of this domain with DNA. Through inclusion of Chd1 sequences in homology searches SLIDE domains were identified in CHD6–9 proteins. Point mutations to conserved amino acids within the human CHD7 SLIDE domain have been identified in patients with CHARGE syndrome
Determination of the b quark mass at the M_Z scale with the DELPHI detector at LEP
An experimental study of the normalized three-jet rate of b quark events with
respect to light quarks events (light= \ell \equiv u,d,s) has been performed
using the CAMBRIDGE and DURHAM jet algorithms. The data used were collected by
the DELPHI experiment at LEP on the Z peak from 1994 to 2000. The results are
found to agree with theoretical predictions treating mass corrections at
next-to-leading order. Measurements of the b quark mass have also been
performed for both the b pole mass: M_b and the b running mass: m_b(M_Z). Data
are found to be better described when using the running mass. The measurement
yields: m_b(M_Z) = 2.85 +/- 0.18 (stat) +/- 0.13 (exp) +/- 0.19 (had) +/- 0.12
(theo) GeV/c^2 for the CAMBRIDGE algorithm. This result is the most precise
measurement of the b mass derived from a high energy process. When compared to
other b mass determinations by experiments at lower energy scales, this value
agrees with the prediction of Quantum Chromodynamics for the energy evolution
of the running mass. The mass measurement is equivalent to a test of the
flavour independence of the strong coupling constant with an accuracy of 7
permil.Comment: 24 pages, 10 figures, Accepted by Eur. Phys. J.
Measurement and Interpretation of Fermion-Pair Production at LEP energies above the Z Resonance
This paper presents DELPHI measurements and interpretations of
cross-sections, forward-backward asymmetries, and angular distributions, for
the e+e- -> ffbar process for centre-of-mass energies above the Z resonance,
from sqrt(s) ~ 130 - 207 GeV at the LEP collider. The measurements are
consistent with the predictions of the Standard Model and are used to study a
variety of models including the S-Matrix ansatz for e+e- -> ffbar scattering
and several models which include physics beyond the Standard Model: the
exchange of Z' bosons, contact interactions between fermions, the exchange of
gravitons in large extra dimensions and the exchange of sneutrino in R-parity
violating supersymmetry.Comment: 79 pages, 16 figures, Accepted by Eur. Phys. J.
A Determination of the Centre-of-Mass Energy at LEP2 using Radiative 2-fermion Events
Using e+e- -> mu+mu-(gamma) and e+e- -> qqbar(gamma) events radiative to the
Z pole, DELPHI has determined the centre-of-mass energy, sqrt{s}, using energy
and momentum constraint methods. The results are expressed as deviations from
the nominal LEP centre-of-mass energy, measured using other techniques. The
results are found to be compatible with the LEP Energy Working Group estimates
for a combination of the 1997 to 2000 data sets.Comment: 20 pages, 6 figures, Accepted by Eur. Phys. J.
Study of Inclusive J/psi Production in Two-Photon Collisions at LEP II with the DELPHI Detector
Inclusive J/psi production in photon-photon collisions has been observed at
LEP II beam energies. A clear signal from the reaction gamma gamma -> J/psi+X
is seen. The number of observed N(J/psi -> mu+mu-) events is 36 +/- 7 for an
integrated luminosity of 617 pb^{-1}, yielding a cross-section of
sigma(J/psi+X) = 45 +/- 9 (stat) +/- 17 (syst) pb. Based on a study of the
event shapes of different types of gamma gamma processes in the PYTHIA program,
we conclude that (74 +/- 22)% of the observed J/psi events are due to
`resolved' photons, the dominant contribution of which is most probably due to
the gluon content of the photon.Comment: 13 pages, 8 figures, Accepted by Phys. Lett.
Evidence for an Excess of Soft Photons in Hadronic Decays of Z^0
Soft photons inside hadronic jets converted in front of the DELPHI main
tracker (TPC) in events of qqbar disintegrations of the Z^0 were studied in the
kinematic range 0.2 < E_gamma < 1 GeV and transverse momentum with respect to
the closest jet direction p_T < 80 MeV/c. A clear excess of photons in the
experimental data as compared to the Monte Carlo predictions is observed. This
excess (uncorrected for the photon detection efficiency) is (1.17 +/- 0.06 +/-
0.27) x 10^{-3} gamma/jet in the specified kinematic region, while the expected
level of the inner hadronic bremsstrahlung (which is not included in the Monte
Carlo) is (0.340 +/- 0.001 +/- 0.038) x 10^{-3} gamma/jet. The ratio of the
excess to the predicted bremsstrahlung rate is then (3.4 +/- 0.2 +/- 0.8),
which is similar in strength to the anomalous soft photon signal observed in
fixed target experiments with hadronic beams.Comment: 37 pages, 9 figures, Accepted by Eur. Phys. J.
A Measurement of the Tau Hadronic Branching Ratios
The exclusive and semi-exclusive branching ratios of the tau lepton hadronic
decay modes (h- v_t, h- pi0 v_t, h- pi0 pi0 v_t, h- \geq 2pi0 v_t, h- \geq 3pi0
v_t, 2h- h+ v_t, 2h- h+ pi0 v_t, 2h- h+ \geq 2pi0 v_t, 3h- 2h+ v_t and 3h- 2h+
\geq 1pi0 v_t) were measured with data from the DELPHI detector at LEP.Comment: 53 pages, 18 figures, Accepted by Eur. Phys. J.
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