6,235 research outputs found
Particle Multiplicity in Jets and Sub-jets with Jet Axis from Color Current
We study the particle multiplicity in a jet or sub-jet as derived from an
energy-multiplicity 2-particle correlation. This definition avoids the notion
of a globally fixed jet axis and allows for the study of smaller jet cone
openings in a more stable way. The results are sensitive to the mean color
current in the jet from primary parton which takes into
account intermediate partonic processes in the sub-jet production where at high energies. We generalize previous calculations in
Leading Logarithmic Approximation (LLA). The size of the effects related to
this jet axis definition are computed for multiplicities in sub-jets with
different opening angles and energies by including contributions from the
Modified LLA (MLLA) and Next-to-MLLA to the leading order QCD results
Phase diagram of an extended Agassi model
Background: The Agassi model is an extension of the Lipkin-Meshkov-Glick
model that incorporates the pairing interaction. It is a schematic model that
describes the interplay between particle-hole and pair correlations. It was
proposed in the 1960's by D. Agassi as a model to simulate the properties of
the quadrupole plus pairing model.
Purpose: The aim of this work is to extend a previous study by Davis and
Heiss generalizing the Agassi model and analyze in detail the phase diagram of
the model as well as the different regions with coexistence of several phases.
Method: We solve the model Hamiltonian through the Hartree-Fock-Bogoliubov
(HFB) approximation, introducing two variational parameters that play the role
of order parameters. We also compare the HFB calculations with the exact ones.
Results: We obtain the phase diagram of the model and classify the order of
the different quantum phase transitions appearing in the diagram. The phase
diagram presents broad regions where several phases, up to three, coexist.
Moreover, there is also a line and a point where four and five phases are
degenerated, respectively.
Conclusions: The phase diagram of the extended Agassi model presents a rich
variety of phases. Phase coexistence is present in extended areas of the
parameter space. The model could be an important tool for benchmarking novel
many-body approximations.Comment: Accepted for publication in PR
An extended Agassi model: algebraic structure, phase diagram, and large size limit
The Agassi model is a schematic two-level model that involves pairing and
monopole-monopole interactions. It is, therefore, an extension of the well
known Lipkin-Meshkov-Glick (LMG) model. In this paper we review the algebraic
formulation of an extension of the Agassi model as well as its bosonic
realization through the Schwinger representation. Moreover, a mean-field
approximation for the model is presented and its phase diagram discussed.
Finally, a analysis, with proportional to the degeneracy of each
level, is worked out to obtain the thermodynamic limit of the ground state
energy and some order parameters from the exact Hamiltonian diagonalization for
finite.Comment: Accepted in Physica Scripta. Focus on SSNET 201
The Dark Side of the Self-Determination Theory and Its Influence on the Emotional and Cognitive Processes of Students in Physical Education
Amongst the main objectives of physical education (PE) classes is the consolidation of healthy lifestyle habits in young people and adolescents. Nonetheless, these classes can also provide the basis from which adverse experiences are generated which affect students’ perceptions of these classes. Previously conducted studies have focused on motivational processes and not on emotional processes, nor on the way in which students learn. The objective of the present study was to explore the dark side of the self-determination theory, its influence on emotional intelligence and the meta-cognitive strategies of students. Methodology: A total of 1602 young people undertaking secondary education participated, with self-reported ages between 13 and 19 years. The following questionnaires were utilized: Controlling Coach Behaviors Scale, Frustration of Psychological Needs in PE classes Scale, Emotional Intelligence in PE Scale and Motivated Strategies for Learning Questionnaire. A structural equation model was developed which explained causal associations between the study variables. Results: Psychological control positively predicted each one of the sub-factors of frustration of psychological needs. Frustration of psychological needs negatively predicted emotional intelligence. Finally, emotional intelligence positively predicted meta-cognitive thinking. Conclusions: The influence and importance of the teaching style adopted by teachers is indicated, in addition to the effect of students’ psychological experiences on emotions and learning strategie
Descubrimiento automático de mappings en un caso de uso real con altas exigencias de certeza
Los sistemas de integración de información resuelven las diferencias entre las fuentes, en la mayoría de los casos, mediante la creación de mappings, puentes semánticos entre los elementos de las fuentes. Hasta ahora se han propuesto comparadores para generar un conjunto de mappings para cada par de elementos de las fuentes a integrar, y se han realizado estudios experimentales con ellos. El valor añadido del presente trabajo frente a los trabajos experimentales anteriores es que se ha llevado a cabo en un caso real embebido en una aplicación real (en el dominio geográfico) con altas exigencias de certeza
Features associated to woody hosts in the bacterial pathogen of olive plants Pseudomonas savastanoi pv. savastanoi
The causal agent of olive knot disease, Pseudomonas savastanoi pv. savastanoi, belongs to the Pseudomonas syringae complex, a bacterial group causing diseases in a broad variety of both woody and herbaceous plant species. Here we summarize our results regarding a set of P. savastanoi pv. savastanoi features exclusively found in the genomes of bacteria from the P. syringae complex isolated from woody hosts. Comparative genomics and evolutionary studies allowed us to identify a 15 kb genomic island (WHOP, from woody host and Pseudomonas), carrying a set of genes involved in degradation of phenolic compounds and exclusively found in bacterial pathogens of woody hosts. Deletion of several WHOP-encoded genes in Pseudomonas savastanoi pv. savastanoi NCPPB 3335 revealed that they play a role in the virulence of the strain in woody olive plants but not in in vitro-grown (nonwoody) plants. In addition, several type III secretion system effectors belonging to the HopAF, HopAO and HopBL families were shown to be clustered across the P. syringae complex according to the woody/herbaceous nature of their host of isolation. Further functional analyses of these virulence factors are needed to facilitate the design of novel strategies directed to control bacterial pathogens of woody hosts.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Comparative Analysis of the Type III Secretion System Effector Repertoires of Pseudomonas savastanoi Pathovars Pathogenic on Woody Hosts
Comunicación de tipo pósterThe species Pseudomonas savastanoi, a member of the Pseudomonas syringae complex,
includes four pathovars causing knots or excrescences in woody hosts: P. savastanoi pv.
savastanoi (Psv), pv. fraxini (Psf), pv. nerii (Psn) and pv. retacarpa (Psr), comprising isolates
from olive, ash, oleander and broom plants, respectively. Pathogenicity of P. savastanoi is
dependent, among other factors, on the type III secretion system (T3SS) and its effector
(T3E) repertoire. Furthermore, a putative role in the interaction with woody hosts has been
suggested for several of these T3E. The recent availability of the genome sequences of
several P. savastanoi strains isolated from different hosts has facilitated bioinformatics
predictions of their T3SS genes and T3E pools, the study of their distribution in other strains
of the P. syringae complex isolated from woody hosts and the functional analysis of several
of these secreted proteins. As previously reported for Psv, Psn and Psf, here we show that
pathogenicity of Psr ICMP16945, is also dependent on the T3SS. Psv strains NCPPB 3335,
ICMP4352 and PseNe107 share a core set of at least 22 T3E, 18 of which are also encoded in
Psn ICMP16943, Psf ICMP7711 and Psr ICMP16945. However, these three strains encode
truncated versions of 1-2 of these 18 T3E and, Psr ICMP16945 contains three pathovarspecific
T3E. Our results also show that several T3E, including HopAO1, are phylogenetically
clustered across the P. syringae complex according to the woody/herbaceous nature of their
host of isolation, suggesting host specialization of these effectors in this complex.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
OEGMerge: a case-based model for merging ontologies
No long ago ontology merging was a necessary activity, however, the current methods used in ontology merging present neither detailed cases nor an accurate formalization. For validating these methods, it is convenient to have a case list as complete as possible. In this paper we present the OEGMerge model, developed from the OEG (Ontological Engineering Group at UPM) experience, which describes precisely the merging casuistic and the actions to carry out in each case. In this first approach, the model covers only the taxonomy of concepts, attributes and relations
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