Bipolar querying of valid-time intervals subject to uncertainty

Databases model parts of reality by containing data representing properties of real-world objects or concepts. Often, some of these properties are time-related. Thus, databases often contain data representing time-related information. However, as they may be produced by humans, such data or information may contain imperfections like uncertainties. An important purpose of databases is to allow their data to be queried, to allow access to the information these data represent. Users may do this using queries, in which they describe their preferences concerning the data they are (not) interested in. Because users may have both positive and negative such preferences, they may want to query databases in a bipolar way. Such preferences may also have a temporal nature, but, traditionally, temporal query conditions are handled specifically. In this paper, a novel technique is presented to query a valid-time relation containing uncertain valid-time data in a bipolar way, which allows the query to have a single bipolar temporal query condition

Spectral classification, HR diagram and distribution of symbiotic stars

45 symbiotic stars observed in the direction of the galactic bulge are classified in spectral type using TiO 6180 Å, 7100 Å and VO λ 6865 Å, absorption feature indices and visual comparation. The effective temperatures obtained are used together with K data from the literature to estimate the bolometric luminosity of the giant components, and the corresponding HR Diagram is plotted together with evolutionary tracks for intermediate mass stars. Statistical distances to the known galactic symbiotic stars are also derived from the calibration of the bolometric luminosities of galactic bulge symbiotic giants. The results are used to gain insight on the mass and evolutionary status of both S- and D- type symbiotic giants, as well as their spatial distribution and position in the stellar populations scheme of our galaxy. The importance of the ST-Teff relation is also addressed.Asociación Argentina de Astronomí

Lesiones en el manguito rotador tras luxación anterior de hombro en pacientes mayores de 40 años.

Se ha realizado un estudio prospectivo de la evolución de 32 luxaciones anteriores de hombro en pacientes de más de 40 años con el objetivo de establecer la incidencia, localización y tipo de rotura del manguito rotador a causa de la luxación, conocer evolución clínica y establecer los criterios clínicos que nos permitan sospechar una rotura del manguito rotador, sin necesidad de recurrir a resonancia magnética (RM) de entrada. Los pacientes fueron sometidos a estudio mediante RM, clasificando las lesiones observadas en cinco grados en función de la extensión de la rotura, siendo el grupo 1 la integridad del manguito. El 90% de los casos presentó una rotura del manguito rotador asociada a la luxación. Tras un periodo de rehabilitación se demostró una diferencia significativa en la recuperación de la abducción en los pacientes con manguito íntegro, siendo un signo clínico de importancia para valorar el estado del manguito rotador.A prospective study of the evolution of 32 anterior dislocations of the shoulder in patients older than forty years has been done with the objective of establishing the incidence, location and kind of tear caused by the dislocation, to know the evolution and to establish the clinical parameters that allow us to suspect an injury of the rotator cuff without the help of magnetic resonance (MR) in the beginning. All the patients were studied with MR, doing a classification of the tears in five degrees, depending on the extension of the tears, being the group 1 the integrity of the rotator cuff. In 90% of the cases a rotator cuff tear has been found to be associated with the dislocation. After the rehabilitation, a significative difference in the recovery of the abduction has been demonstrated in the patients with integrity of the rotator cuff, being an important clinical sign to know the state of the rotator cuff

Refugee Women’s Experiences of Violence and Resilience: Early Explorations

Refugee experiences of violence are well known and may include violence in the country of origin, in refugee camps, countries of detention and, especially for women and children, in their own families before and after resettlement. The resilience of former refugees to violence has been noted in recent times by a range of agencies. Across Australia, a number of initiatives are in place to deal with experiences of violence in these communities, including policing programs, settlement support services, community support groups and torture and trauma survival services. This paper will report on the preliminary findings of a qualitative project investigating the relationship between refugee women, violence and resilience in the context of resettlement. Focusing on interviews with service providers, the paper will explore how resilience is understood within, and may impact on, service provision.Sydney Institute of Criminology; School of Social Sciences at the University of Western Sydne

Spin Transport in Two Dimensional Hopping Systems

A two dimensional hopping system with Rashba spin-orbit interaction is considered. Our main interest is concerned with the evolution of the spin degree of freedom of the electrons. We derive the rate equations governing the evolution of the charge density and spin polarization of this system in the Markovian limit in one-particle approximation. If only two-site hopping events are taken into account, the evolution of the charge density and of the spin polarization is found to be decoupled. A critical electric field is found, above which oscillations are superimposed on the temporal decay of the total polarization. A coupling between charge density and spin polarization occurs on the level of three-site hopping events. The coupling terms are identified as the anomalous Hall effect and the recently proposed spin Hall effect. Thus, an unpolarized charge current through a sheet of finite width leads to a transversal spin accumulation in our model system.Comment: 15 pages, 3 figure

The beat of a fuzzy drum: fuzzy Bessel functions for the disc

The fuzzy disc is a matrix approximation of the functions on a disc which preserves rotational symmetry. In this paper we introduce a basis for the algebra of functions on the fuzzy disc in terms of the eigenfunctions of a properly defined fuzzy Laplacian. In the commutative limit they tend to the eigenfunctions of the ordinary Laplacian on the disc, i.e. Bessel functions of the first kind, thus deserving the name of fuzzy Bessel functions.Comment: 30 pages, 8 figure

Numerical simulations of a non-commutative theory: the scalar model on the fuzzy sphere

We address a detailed non-perturbative numerical study of the scalar theory on the fuzzy sphere. We use a novel algorithm which strongly reduces the correlation problems in the matrix update process, and allows the investigation of different regimes of the model in a precise and reliable way. We study the modes associated to different momenta and the role they play in the ``striped phase'', pointing out a consistent interpretation which is corroborated by our data, and which sheds further light on the results obtained in some previous works. Next, we test a quantitative, non-trivial theoretical prediction for this model, which has been formulated in the literature: The existence of an eigenvalue sector characterised by a precise probability density, and the emergence of the phase transition associated with the opening of a gap around the origin in the eigenvalue distribution. The theoretical predictions are confirmed by our numerical results. Finally, we propose a possible method to detect numerically the non-commutative anomaly predicted in a one-loop perturbative analysis of the model, which is expected to induce a distortion of the dispersion relation on the fuzzy sphere.Comment: 1+36 pages, 18 figures; v2: 1+55 pages, 38 figures: added the study of the eigenvalue distribution, added figures, tables and references, typos corrected; v3: 1+20 pages, 10 eps figures, new results, plots and references added, technical details about the tests at small matrix size skipped, version published in JHE

The Fuzzy Disc

We introduce a finite dimensional matrix model approximation to the algebra of functions on a disc based on noncommutative geometry. The algebra is a subalgebra of the one characterizing the noncommutative plane with a * product and depends on two parameters N and theta. It is composed of functions which decay exponentially outside a disc. In the limit in which the size of the matrices goes to infinity and the noncommutativity parameter goes to zero the disc becomes sharper. We introduce a Laplacian defined on the whole algebra and calculate its eigenvalues. We also calculate the two--points correlation function for a free massless theory (Green's function). In both cases the agreement with the exact result on the disc is very good already for relatively small matrices. This opens up the possibility for the study of field theories on the disc with nonperturbative methods. The model contains edge states, a fact studied in a similar matrix model independently introduced by Balachandran, Gupta and Kurkcuoglu.Comment: 17 pages, 8 figures, references added and correcte

Renormalization group and nonequilibrium action in stochastic field theory

We investigate the renormalization group approach to nonequilibrium field theory. We show that it is possible to derive nontrivial renormalization group flow from iterative coarse graining of a closed-time-path action. This renormalization group is different from the usual in quantum field theory textbooks, in that it describes nontrivial noise and dissipation. We work out a specific example where the variation of the closed-time-path action leads to the so-called Kardar-Parisi-Zhang equation, and show that the renormalization group obtained by coarse graining this action, agrees with the dynamical renormalization group derived by directly coarse graining the equations of motion.Comment: 33 pages, 3 figures included in the text. Revised; one reference adde

Identification and characterization of a nodH ortholog from the alfalfa-nodulating Or191-like rhizobia

Nodulation of Medicago sativa (alfalfa) is known to be restricted to Sinorhizobium meliloti and a few other rhizobia that include the poorly characterized isolates related to Rhizobium sp. strain Or191. Distinctive features of the symbiosis between alfalfa and S. meliloti are the marked specificity from the plant to the bacteria and the strict requirement for the presence of sulfated lipochitooligosaccharides (Nod factors [NFs]) at its reducing end. Here, we present evidence of the presence of a functional nodH-encoded NF sulfotransferase in the Or191-like rhizobia. The nodH gene, present in single copy, maps to a high molecular weight megaplasmid. As in S. meliloti, a nodF homolog was identified immediately upstream of nodH that was transcribed in the opposite direction (local synteny). This novel nodH ortholog was cloned and shown to restore both NF sulfation and the Nif +Fix+ phenotypes when introduced into an S. meliloti nodH mutant. Unexpectedly, however, nodH disruption in the Or191-like bacteria did not abolish their ability to nodulate alfalfa, resulting instead in a severely delayed nodulation. In agreement with evidence from other authors, the nodH sequence analysis strongly supports the idea that the Or191-like rhizobia most likely represent a genetic mosaic resulting from the horizontal transfer of symbiotic genes from a sinorhizobial megaplasmid to a not yet clearly identified ancestor.Instituto de Biotecnologia y Biologia Molecula