1,722 research outputs found
Seismic vulnerability assessment: Methodological elements and applications to the case of Romania
This paper is intended to present some studies undertaken in order to develop a seismic vulnerability estimation system to fit the needs of development of earthquake scenarios and of development of an integrated disaster risk management system for Romania. Methodological aspects are dealt with, in connection with the criteria of categorization of buildings, with the definition of parameters used for characterizing vulnerability, with the setting up of an inventory of buildings and with the calibration of parameters characterizing vulnerability. Action was initiated along the coordinates referred to in connection with the methodological aspects mentioned above. The approach was made, as far as possible, specific to the conditions of Romania. Some data on results obtained to date are presented.seismic vulnerability, vulnerability estimation, earthquake scenarios, categorization of buildings, inventory of buildings, expected earthquake impact
Second order perturbation theory for embedded eigenvalues
We study second order perturbation theory for embedded eigenvalues of an
abstract class of self-adjoint operators. Using an extension of the Mourre
theory, under assumptions on the regularity of bound states with respect to a
conjugate operator, we prove upper semicontinuity of the point spectrum and
establish the Fermi Golden Rule criterion. Our results apply to massless
Pauli-Fierz Hamiltonians for arbitrary coupling.Comment: 30 pages, 2 figure
Flammability Tests on Hot Surface for Several Hydraulic Fluids
Industrial equipment using hydraulic fluids are design to accept higher load and speed, implicitly higher temperatures, including for fluids. Leakages from enclosures like gear boxes or hydraulic systems could increase the risk of fluid reaching hot surfaces, thus producing fires hard to be controlled and isolated. The designer have to evaluate the flammability of fluids and they should select several solutions for a particular application in order to estimate the costs of different solutions and to mitigate the risk of having accidental fires due to a specific fluid grade. The tests were done with the help of an original equipment allowing a dedicated soft assistance in order to protect the operator and to sustain reproducibility, according to the standard SR EN ISO 20823:2004 Petroleum and related products. The determination of the flammability characteristics of fluids in contact with hot surfaces - Manifold ignition test, There were tested the following grades of hydraulic oil HLP 68 X-Oil, HFC Prista, MHE 40 Prista (100% oil), a rapeseed oil (obtained after a dewaxing process) and an emulsion oil-in-water (5% vol. MHE 40 Prista). There were identified distinct behaviours of these fluids under the test condition
Genetic survey of alveolar and cystic echinococcoses in Romania: first molecular evidence of Echinococcus multilocularis in humans in the country
Cystic echinococcosis (CE) and alveolar echinococcosis (AE) are considered as one of the most
important zoonotic diseases in Romania, where they are subject to mandatory reporting. To obtain
more knowledge about the genetic diversity of Echinococcus causative agents of these diseases, 11
isolates from humans and ungulate intermediate hosts from the two regions of Romania were genotyped
using mitochondrial markers. In clinical samples of fi ve patients from north-eastern Romania
(Iasi, Botosani, Vaslui counties), Echinococcus multilocularis was identifi ed as causal agent by cox1
sequence analysis. To the best of our knowledge this fi nding presents the fi rst molecular evidence
of E. multilocularis in humans from Romania. Only two cases of AE in patients were previously documented
in the country by serological methods. In our four patients the most widespread European
variant E5 of E. multilocularis was recorded, whereas in isolate from Vaslui county three nucleotide
substitutions were detected as compared to the most related E5 haplotype. One of these mutations
(411T/G) matched N1 and N2 haplotypes described previously from North America. In six CE samples
retrieved from western Romania (Caras-Severin and Timis counties), two human isolates were
diagnosed as Echinococcus canadensis G7, one as E. granulosus s.s. G1 and one as E. granulosus
s.s. G3 using atp6 and rrnS sequencing. In ungulates, the cattle isolate was allocated to E. granulosus
s.s. G1 and pig isolate to E. canadensis G7. The two G7 fi ndings in humans reinforced the
recent view that G7 was underestimated as compared to the E. granulosus s.s. regarding human
CE threat that can be further employed for identifying sources of infections and establishing suitable
preventive measures
Automatic Liver Segmentation Using an Adversarial Image-to-Image Network
Automatic liver segmentation in 3D medical images is essential in many
clinical applications, such as pathological diagnosis of hepatic diseases,
surgical planning, and postoperative assessment. However, it is still a very
challenging task due to the complex background, fuzzy boundary, and various
appearance of liver. In this paper, we propose an automatic and efficient
algorithm to segment liver from 3D CT volumes. A deep image-to-image network
(DI2IN) is first deployed to generate the liver segmentation, employing a
convolutional encoder-decoder architecture combined with multi-level feature
concatenation and deep supervision. Then an adversarial network is utilized
during training process to discriminate the output of DI2IN from ground truth,
which further boosts the performance of DI2IN. The proposed method is trained
on an annotated dataset of 1000 CT volumes with various different scanning
protocols (e.g., contrast and non-contrast, various resolution and position)
and large variations in populations (e.g., ages and pathology). Our approach
outperforms the state-of-the-art solutions in terms of segmentation accuracy
and computing efficiency.Comment: Accepted by MICCAI 201
On perturbations of Dirac operators with variable magnetic field of constant direction
We carry out the spectral analysis of matrix valued perturbations of
3-dimensional Dirac operators with variable magnetic field of constant
direction. Under suitable assumptions on the magnetic field and on the
pertubations, we obtain a limiting absorption principle, we prove the absence
of singular continuous spectrum in certain intervals and state properties of
the point spectrum. Various situations, for example when the magnetic field is
constant, periodic or diverging at infinity, are covered. The importance of an
internal-type operator (a 2-dimensional Dirac operator) is also revealed in our
study. The proofs rely on commutator methods.Comment: 12 page
Methylation landscape in the genome of higher plants of agronomical interest
In eukaryotic cells the methylation of cytosines in DNA is an essential mechanism which is implied in the dynamic organization of the genome structure, in relation to genes expression. Plant genomes contain a significant proportion and variable according to the species, of sequences which are likely to be methylated during the life of the plant. It is known that the establishment and the maintenance of methylation profiles in both genomic areas and specific sequences constitute a crucial mediator in the modulation of genes expression during development. Recent studies have evidenced the implication of epimutations in the adaptation of plants to their environment particularly in response to biotic and abiotic stresses. Recently, the complete mapping of methylation in the genomes of Arabidopsis thaliana and rice provided invaluable information on the distribution of methylation within genes in relation to their expression. The impact of changes in the methylation profiles on the characters of agronomic importance has not been intensively studied yet, whereas this question takes a considerable importance in the context of an increasing food demand and foreseen global climate changes. The METHYLANDSCAPE project proposes to isolate genomic DNA sequences on the basis of their degree of methylation and to connect the variation of their methylation profiles with, on the one hand, the expression of the corresponding genes and, on the other hand, with environmental or developmental processes. Thus, it should be possible to identify genes which expression is differentially controlled by methylation during development and/or in situation of stress, and likely to have an influence on the agronomic value of the plant. The METHYLANDSCAPE partners thus propose to bring signification advances in plant genomics on four original species, by integrating DNA methylation mapping and the relationship between epigenome and transcriptome, up to the generation of methylation-sensitive markers linked with characters of agronomic importance. (Texte intégral
Spectral theory for a mathematical model of the weak interaction: The decay of the intermediate vector bosons W+/-, II
We do the spectral analysis of the Hamiltonian for the weak leptonic decay of
the gauge bosons W+/-. Using Mourre theory, it is shown that the spectrum
between the unique ground state and the first threshold is purely absolutely
continuous. Neither sharp neutrino high energy cutoff nor infrared
regularization are assumed.Comment: To appear in Ann. Henri Poincar\'
- âŠ