Dilatonic, Current-Carrying Cosmic String

We study the implications of a scalar-tensorial gravity for the metric of an isolated self-gravitating superconducting cosmic string. These modifications are induced by an arbitrary coupling of a massless scalar field to the usual tensorial field in the gravitational Lagrangian. We derive the metric in the weak-field approximation and we analyse the behaviour of light in this spacetime. We end with some discussions.Comment: 12 pp, Latex, no figures, based on a talk given by M. E. X. Guimaraes at the COSMO 99, 27/9 to 02/10/99, ICTP, Trieste, I

On the duality in four-dimensional Lorentz-breaking field theories

We consider new issues of duality in four-dimensional Lorentz-breaking field theories. In particular, we demonstrate that the arising of the aether-like Lorentz-breaking term is necessary in order for the 4D models to display the duality analog between the MCS and self-dual models in 3D. We further study the dispersion relations in both theories and discuss the physical contents of the models involved in this new dualilty.Comment: 16 page

Impacto de agrotoxicos utilizados na cultura do tomateiro a adultos de Trichogramma pretiosum Riley (Hym.: Trichogrammatidae)

O presente trabalho objetivou avaliar o impacto de (g. i. a. L de água)Bacillus thuringiensis (0.05), Chlorantraniliprole (0.04), Etifenoprox (0.13), Fenpropathrin (0.45), Triflumuron (0.144), Azoxystrobin (0.15), Diphenconazole (0.125), tebuconazole (0.2), fluazitop-p-butil (2.5) e metribuzin (2.4) recomendados para o controle de pragas (insetos, doenças e plantas daninhas na cultura do tomateiro.Resumo

On the duality of three-dimensional superfield theories

Within the superfield approach, we consider the duality between the supersymmetric Maxwell-Chern-Simons and self-dual theories in three spacetime dimensions. Using a gauge embedding method, we construct the dual theory to the self-dual model interacting with a matter superfield, which turns out to be not the Maxwell-Chern-Simons theory coupled to matter, but a more complicated model, with a ``restricted'' gauge invariance. We stress the difficulties in dualizing the self-dual field coupled to matter into a theory with complete gauge invariance. After that, we show that the duality, achieved between these two models at the tree level, also holds up to the lowest order quantum corrections.Comment: 18 pages,2 figures, revtex4, v2: corrected reference

Pneumocephalus Following Unidentified Dural Puncture: A Case Report with an Unusual Neurological Presentation

Pneumocephalus is a rare consequence of epidural anesthesia, which may occur following inadvertent or unidentified dural puncture when the loss of resistance to air technique is applied to identify the epidural space. Headache is the most common symptom presented in this condition, usually with sudden onset. This case report describes an unusual presentation of diffuse pneumocephalus after an unidentified dural puncture. The patient (male, 67 years old) was submitted to epidural catheter placement for the treatment of acute exacerbation of ischemic chronic pain using loss of resistance to air technique. No cerebrospinal fluid or blood flashback was observed after needle withdrawal. Shortly after the intervention, the patient presented symptoms of lethargy, apathy, and hypophonia, which are not commonly associated with pneumocephalus. No motor or sensory deficits were detected. Cranial computed tomography showed air in the frontal horn of the left ventricle, subarachnoid space at interhemispheric fissure and basal cisterns, confirming the diagnosis of diffuse pneumocephalus. The patient remained under vigilance with oxygen therapy and the epidural catheter left in place. After 24 hours, cranial computed tomography showed air in the temporal and frontal horns of the left ventricle, with no air in the subarachnoid space. The patient presented no neurological signs or symptoms at this time. Although headache is the most common symptom presented in reported cases of pneumocephalus, this case shows the need for the clinician to be aware of other signs and symptoms that may be indicative of this condition, in order to properly diagnose and treat these patients.info:eu-repo/semantics/publishedVersio

A study of the Higgs and confining phases in Euclidean SU(2) Yang-Mills theories in 3d by taking into account the Gribov horizon

We study SU(2) three-dimensional Yang-Mills theories in presence of Higgs fields in the light of the Gribov phenomenon. By restricting the domain of integration in the functional integral to the first Gribov horizon, we are able to discuss a kind of transition between the Higgs and the confining phase in a semi-classical approximation. Both adjoint and fundamental representation for the Higgs field are considered, leading to a different phase structure.Comment: 12 pages. Version accepted for publication in the EPJ